Geochemical modelling of groundwater evolution and residence time at the Olkiluoto site

Energy Technology Data Exchange (ETDEWEB)

Pitkaenen, P.; Luukkonen, A. [VTT Communities and Infrastructure, Espoo (Finland); Ruotsalainen, P. [Fintact Oy (Finland); Leino-Forsman, H.; Vuorinen, U. [VTT Chemical Technology, Espoo (Finland)

1999-05-01

An understanding of the geochemical evolution of groundwater is an essential part of the performance assessment and safety analysis of the final disposal of radioactive waste into the bedrock. The performance of technical barriers and migration of possibly released radionuclides depend on chemical conditions. A prerequisite for understanding these factors is the ability to specify the water-rock interactions which control chemical conditions in groundwater. The objective of this study is to interpret the processes and factors which control the hydrogeochemistry, such as pH and redox conditions. A model of the hydrogeochemical progress in different parts of the crystalline bedrock at Olkiluoto has been created and the significance of chemical reactions and groundwater mixing along different flowpaths calculated. Long term hydrodynamics have also been evaluated. The interpretation and modelling are based on water samples (63 altogether) obtained from precipitation, Baltic Sea, soil layer, shallow wells in the bedrock, and eight deep boreholes in the bedrock for which a comprehensive data set on dissolved chemical species and isotopes was available. Some analyses of dissolved gases and fracture calcite and their isotopic measurements were also utilised. The data covers the bedrock at Olkiluoto to a depth of 1000 m. The results from groundwater chemistry, isotopes, petrography, hydrogeology of the site, geomicrobial studies, and PCA and speciation calculations were used in the evaluation of evolutionary processes at the site. The geochemical interpretation of water-rock interaction, isotope-chemical evolution and mixing of palaeo water types were approached by mass-balance calculations (NETPATH). Reaction-path calculations (EQ3/6) were used to verify the thermodynamic feasibility of the reaction models obtained. The interpretation and calculation of hydrochemical data from Olkiluoto reveals the complex nature of hydrogeochemical evolution at the site. Changes in

Site scale groundwater flow in Olkiluoto - complementary simulations

International Nuclear Information System (INIS)

Loefman, J.

2000-06-01

This work comprises of the complementary simulations to the previous groundwater flow analysis at the Olkiluoto site. The objective is to study the effects of flow porosity, conceptual model for solute transport, fracture zones, land uplift and initial conditions on the results. The numerical simulations are carried out up to 10000 years into the future employing the same modelling approach and site-specific flow and transport model as in the previous work except for the differences in the case descriptions. The result quantities considered are the salinity and the driving force in the vicinity of the repository. The salinity field and the driving force are sensitive to the flow porosity and the conceptual model for solute transport. Ten-fold flow porosity and the dual-porosity approach retard the transport of solutes in the bedrock resulting in brackish groundwater conditions at the repository at 10000 years A.P. (in the previous work the groundwater in the repository turned into fresh). The higher driving forces can be attributed to the higher concentration gradients resulting from the opposite effects of the land uplift, which pushes fresh water deeper and deeper into the bedrock, and the higher flow porosity and the dual-porosity model, which retard the transport of solutes. The cases computed (unrealistically) without fracture zones and postglacial land uplift show that they both have effect on the results and can not be ignored in the coupled and transient groundwater flow analyses. The salinity field and the driving force are also sensitive to the initial salinity field especially at the beginning during the first 500 years A.P. The sensitivity will, however, diminish as soon as fresh water dilutes brackish and saline water and decreases the concentration gradients. Fresh water conditions result in also a steady state for the driving force in the repository area. (orig.)

Olkiluoto site description 2011

International Nuclear Information System (INIS)

2012-12-01

This fourth version of the Olkiluoto Site Report, produced by the OMTF (Olkiluoto Modelling Task Force), updates the Olkiluoto Site Report 2008 with the data and knowledge obtained up to December 2010. A descriptive model of the site (the Site Descriptive Model, SDM), i.e. a model describing the geological and hydrogeological structure of the site, properties of the bedrock and the groundwater and its flow, and the associated interacting processes and mechanisms. The SDM is divided into six parts: surface system, geology, rock mechanics, hydrogeology, hydrogeochemistry and transport properties

Olkiluoto site description 2011

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

This fourth version of the Olkiluoto Site Report, produced by the OMTF (Olkiluoto Modelling Task Force), updates the Olkiluoto Site Report 2008 with the data and knowledge obtained up to December 2010. A descriptive model of the site (the Site Descriptive Model, SDM), i.e. a model describing the geological and hydrogeological structure of the site, properties of the bedrock and the groundwater and its flow, and the associated interacting processes and mechanisms. The SDM is divided into six parts: surface system, geology, rock mechanics, hydrogeology, hydrogeochemistry and transport properties.

{sup 18}O, {sup 2}H and {sup 3}H isotopic composition of precipitation and shallow groundwater in Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Hendriksson, N. [Geological Survey of Finland, Espoo (Finland); Karhu, J.; Niinikoski, P. [Univ. of Helsinki (Finland)

2014-12-15

The isotopic composition of oxygen and hydrogen in local precipitation is a key parameter in the modelling of local water circulation. This study was initiated in order to provide systematic monthly records of the isotope content of atmospheric precipitation in the Olkiluoto area and to establish the relation between local rainfall and newly formed groundwater. During January 2005 - December 2012, a total of 85 cumulative monthly rainfall samples and 68 shallow groundwater samples were collected and the isotopic composition of oxygen and hydrogen was recorded for all those samples. Tritium values are available for 79 precipitation and 65 groundwater samples. Based on the 8-year monitoring, the long-term weighted annual mean isotope values of precipitation and the mean values of shallow groundwater are -11.59 per mille and -11.27 per mille for δ{sup 18}O, - 82.3 per mille and -80.3 per mille for δ{sup 2}H and 9.8 and 9.1 TU for tritium, respectively. Based on these data, the mean stable isotope ratios of groundwater represent the long-term mean annual isotopic composition of local precipitation. The precipitation data were used to establish the local meteoric water line (LMWL) for the Olkiluoto area. The line is formulated as: δ{sup 2}H = 7.45 star δ{sup 18}O + 3.82. The isotope time series reveal a change in time. The increasing trend for the δ{sup 18}O and δ{sup 2}H values may be related to climatic variability while the gradual decline observed in the {sup 3}H data is attributed to the still continuing decrease in atmospheric {sup 3}H activity in the northern hemisphere. The systematic seasonal and long-term tritium trends suggest that any potential ground-level tritium release from the Olkiluoto nuclear power plants is insignificant. The d-excess values of Olkiluoto precipitation during the summer period indicated that a notable amount of re-cycled Baltic Sea water may have contributed to precipitation in the Finnish southern coast. Preliminary estimates

Geochemical modelling of the groundwater at the Olkiluoto site

International Nuclear Information System (INIS)

Pitkaenen, P.; Snellman, M.; Leino-Forsman, H.; Vuorinen, U.

1994-04-01

A preliminary model for probable processes responsible for the evolution of the groundwater at the nuclear waste investigation site Olkiluoto (in Finland) is presented. The hydrological data was collected from boreholes drilled down to 1000-m depth into crystalline bedrock. Based on chemical, isotopic, petrographic and hydrological data as well as ion plots and speciation calculations with PHREEQE the thermodynamic controls on the water composition and trends constraining these processes are evaluated. In order to determine the reactions which can explain the changes along the flow path during the evolution of groundwater system and to determine to which extent these reactions take place, mass-balance calculations with the NETPATH program were used. Mass transfer calculations with the EQ6 program were used to test the feasibility of the model derived, to predict reaction paths and composition of equilibrium solutions for the redox reactions. (57 refs., 43 figs., 10 tabs.)

Quantitation and identification of methanogens and sulphate reducers in Olkiluoto groundwater

International Nuclear Information System (INIS)

Bomberg, M.; Nyyssoenen, M.; Itaevaara, M.

2010-08-01

involved in methanogenesis (mcrA) or sulphate reduction (dsrB) and enables the study of these microbial processes in the deep bedrock groundwater. In the GEOFUNC project, groundwater samples were studied from depths ranging from -14.5 m to -581 m comprising samples from both drillholes in Olkiluoto and groundwater stations in the ONKALO. Methanogenic archaea were present in almost all samples. The highest number of methanogens was detected in the samples ONK-PVA1 (-14.5 m), OL-KR40 (-349 to -351 m and -545 to -553 m) and OL-KR47 (-334 to -338 m) and OL-KR23 (-347 to -376 m). In the samples, where the salinity exceeded 19 g/l (Cl, Na, Ca), the number of methanogens was very low. Sulphate reducing bacteria were present in all studied samples. The highest number of sulphate reducers were detected in the samples ONK-PVA1 (-14.5 m), OL-KR23 (-347 to -376 m) and OLKR11 (-531 to -558 m) and OL-KR40 (-545 to -553 m), however, the last two samples are evident artefact mixtures of SO4 - and CH4 -rich groundwaters, thus they do not represent undisturbed in situ conditions in groundwater system. The diversity of methanogens changed in relation to depth and a clear division into phylogenetic groups containing either mcrA sequences from samples close to the land surface or mcrA sequences from deeper samples. The sulphate reducers were different in all studied samples. Despite their important ecological functions, both methanogens and sulphate reducers were present as only small fractions of the total microbial community in the Olkiluoto groundwater. The methanogens comprised at the most 0.44 % of the microbial community (-349 m) and the sulphate reducers 1.55 % (-14.5 m) and 1.3 % (-531 m). The results presented in this report give indications to the diversity and quantity of the populations of methanogenic archaea and sulphate reducing bacteria in the deep groundwater of Olkiluoto. In spite of the small number of methanogens and sulphate reducers in the environment there ecological

Evolution of the Olkiluoto site. Palaeohydrogeochemical considerations

International Nuclear Information System (INIS)

Smellie, J.; Pitkaenen, P.; Koskinen, L.

2014-05-01

present times at Olkiluoto. Investigation results from matrix porewaters and fracture groundwaters indicate at least five to six different end-member water types that have contributed to current groundwater compositions. Salinity in these end-member waters varies from fresh water to highly saline brine and they seem to represent source waters from different environmental conditions, i.e. meteoric and marine waters from glacial to warm, and humid to arid climates. There are, however, several areas of uncertainty that have been highlighted during the present study that need to be resolved. For example, attempts to integrate the hydrogeology, groundwater chemistry and porewater chemistry, and their relationship to the palaeoevolution of the Olkiluoto site before and since the start of last glaciation, have encountered some difficulties. These include the choice of initial boundary conditions for the hydrogeological modelling, the necessity to consider alternative scenarios to explain present groundwater conditions, the choice of model input parameter values for diffusion and matrix pore diffusivity, and resolving potential problems associated with sampling and analysis of the porewaters. Some uncertainties are also related to the experimentally derived porewater concentrations. For example, one explanation to salinity differences between matrix porewaters and fracture groundwaters may be anion exclusion which has been interpreted in several laboratory experiments based on Olkiluoto and Finnish rock samples. Presently plans and studies are underway to address the many uncertainties that have resulted from this study and additional corroborative (or otherwise) data should be available in the near future. (orig.)

Evolution of the Olkiluoto site. Palaeohydrogeochemical considerations

Energy Technology Data Exchange (ETDEWEB)

Smellie, J. (ed.) [Conterra AB, Stockholm (Sweden); Pitkaenen, P.; Koskinen, L.; and others

2014-05-15

present times at Olkiluoto. Investigation results from matrix porewaters and fracture groundwaters indicate at least five to six different end-member water types that have contributed to current groundwater compositions. Salinity in these end-member waters varies from fresh water to highly saline brine and they seem to represent source waters from different environmental conditions, i.e. meteoric and marine waters from glacial to warm, and humid to arid climates. There are, however, several areas of uncertainty that have been highlighted during the present study that need to be resolved. For example, attempts to integrate the hydrogeology, groundwater chemistry and porewater chemistry, and their relationship to the palaeoevolution of the Olkiluoto site before and since the start of last glaciation, have encountered some difficulties. These include the choice of initial boundary conditions for the hydrogeological modelling, the necessity to consider alternative scenarios to explain present groundwater conditions, the choice of model input parameter values for diffusion and matrix pore diffusivity, and resolving potential problems associated with sampling and analysis of the porewaters. Some uncertainties are also related to the experimentally derived porewater concentrations. For example, one explanation to salinity differences between matrix porewaters and fracture groundwaters may be anion exclusion which has been interpreted in several laboratory experiments based on Olkiluoto and Finnish rock samples. Presently plans and studies are underway to address the many uncertainties that have resulted from this study and additional corroborative (or otherwise) data should be available in the near future. (orig.)

Analysis results of PAVE sampling of groundwaters from open boreholes OL-KR2, OL-KR7, OL-KR13 and OL-KR15 at Olkiluoto, Eurajoki, in 2004

Energy Technology Data Exchange (ETDEWEB)

Hirvonen, H. [Teollisuuden Voima Oyj, Eurajoki (Finland); Hatanpaa, E. [lnsinoeoeritoimisto Paavo Ristola Oy, Hollola (Finland)

2005-12-15

Four groundwater samples were collected at Olkiluoto from open boreholes OL-KR2, OL-KR7, OL-KR13 and OL-KR15 with pressurised water sampling equipment (PAVE) between summer 2004 and the beginning of 2005. The aim of the ground water sampling was to get information for the basis of the monitoring program during ONKALO construction. Sampling sections were mainly chosen so that the results of the chemical analyses from earlier studies could be used for comparison. This study is a part of Olkiluoto's monitoring programme (OMO). This study presents the sampling methods and the results of the laboratory analyses of groundwater samples from the open boreholes OL-KR2/328.5-330.5 m, OL-KR7/275.5- 289.5 m, OL-KR13/362-365 m and OL-KR15/241-245 m. The analytical results of the groundwater samplings are compared to earlier analytical results. According to Davis and De Wiest's ( 1967) classification, all ground water samples represent the borehole water type Na-Cl. All ground water samples were brackish ( 1000 mg/L < TDS < 1 0000 mg/L) according to Davis's ( 1964) TDS classification. Comparison of analytical results of the samples to earlier results shows that some changes have occurred between samplings. Other parameters, with couple of particular exceptions, have a downward trend, but bicarbonate concentration has increased in all boreholes. Concentrations of main parameters have changed most in OL-KR7 and OL-KR13 waters. Gas analyses results have not changed significantly, but increased carbon dioxide concentration is noticed in gas analysis results also. (orig.)

Groundwater sampling from shallow boreholes (PP and PR) and groundwater observation tubes (PVP) at Olkiluoto in 2004

Energy Technology Data Exchange (ETDEWEB)

Hirvonen, H. [Teollisuuden Voima Oyj, Eurajoki (Finland)

2005-11-15

Groundwater sampling from the shallow boreholes and groundwater observation tubes was performed in summer 2004 (PP2, PP3, PP7, PP8, PRl, PVPl, PVP3A, PVP3B, PVP4A and PVP4B) and in autumn 2004 (PP2, PP3, PP5, PP7, PP8, PP9, PP36, PP37, PP39, PR1, PR2, PVP1, PVP3A, PVP3B, PVP4A, PVP8A, PVP9A, PVP9B, PVP10B, PVP11, PVP12, PVP13, PVP14 and PVP20). The results from previous samplings have been used in the hydrogeochemical baseline characterization at Olkiluoto and some of the latest results have also been part of the ONKALO monitoring program. This study contains data on preliminary pumping of the sampling points and pumping for groundwater sampling and chemical analyses in the laboratory. This study also includes comparison with analytical results obtained between 1995-2004. The total dissolved solids (TDS) of groundwater samples were mainly below 1000 mg/L. According to Davis's TDS classification, these waters were fresh waters. The only exception was the water sample from shallow borehole PP7 (1400mg/L and 1450mg/L), which was brackish. Several different groundwater types were observed, but the most common water type was Ca-HCO{sub 3} (five samples). Analytical results from 1995-2003 were compared. During 2001-2003 in groundwater samples from sampling points PVP1, PVP9A and PP7 all measured main parameters changed considerably, but from summer 2003 to autumn 2004 the greatest alterations occurred in PR2, PVP1, PVP3A and PVP3B waters. These changes can be seen in almost all parameters. For other samples only minor changes in results were observed during the reference period. (orig.)

Results of Monitoring at Olkiluoto in 2007. Hydrogeochemistry

Energy Technology Data Exchange (ETDEWEB)

Pitkaenen, P.; Partamies, S. (VTT, Espoo (Finland)); Lahdenperae, A.-M.; Ahokas, T.; Penttinen, T. (Poeyry Environment Oy, Vantaa (Finland)); Lehtinen, A. (Posiva Oy, Helsinki (Finland)); Pedersen, K. (Microbial Analytics Sweden AB (Sweden)); Lamminmaeki, T. (Teollisuuden Voima Oy, Olkiluoto (Finland)); Hatanpaeae, E. (Ramboll Analytics Oy, Lahti (Finland))

2008-07-15

. Hydrogeochemical development in them requires close monitoring in the future. The gas results also correspond very well to the baseline data suggesting no influence of ONKALO on the groundwater conditions, although gases are not considered to be as sensitive indicators of changes as dissolved solids. Groundwater sampling from ONKALO has so far not revealed notably high SO{sub 4} contents, which are relatively common in surface based sampling at 100 to 300 m depth. The number of groundwater samples and the potential sampling locations are small after excavation passed through HZ19 at about 100 m depth due to low permeability of the host rock. The 2H- and 18O- compositions in samples taken from ONK-KR3 and particularly ONK-KR4 show a tendency towards isotopic composition of Korvensuo water, suggesting that water from the reservoir may discharge in these drillholes. Earlier shallow groundwater data from bedrock between ONKALO and Korvensuo are lacking, making it impossible to evaluate if this is caused by ONKALO or if water from the reservoir has already earlier infiltrated and mixed in the shallow depths. Microbiological data obtained during the 2007 monitoring programme with three independent methods support the results that suggest the 300 m depth level in Olkiluoto to be more active with respect to microbiological processes than the depth interval between 20 and 250 m. Starting at a depth of approximately 300 m, there are steep gradients of decreasing sulphate and increasing methane concentrations with depth; together with the peaks in biomass and sulphide concentration at this depth (Pedersen 2008) these suggest that anaerobic methane oxidation may be a significant process at 300 m depth in Olkiluoto. Gefinex S400 sounding curves show slight changes in comparison with the 2004 - 2006 ARD curves. The differences may mostly be caused by the new earthwork structures or the alteration of the moisture of soil and bedrock. According to the monitoring results, decreasing resistivity

Reactive transport predictions for an Olkiluoto. Final repository tunnel unit

International Nuclear Information System (INIS)

Luukkonen, A.; Nordman, H.

2007-09-01

The presented hydrogeochemical reactive transport calculations concentrate to a defined unit piece (unit cell) of the planned Olkiluoto repository that is under design for spent nuclear fuel. The material properties assigned to the tunnel unit are based on literature as far as possible. Calculations make up geochemical future scenarios on the repository evolution. Most recent predictions on the potential future climate at Olkiluoto are utilised together with estimates how future hydraulic conditions affect the repository. Two climate scenarios are considered in detail. The Weichselian-R scenario is based on the repetition of the last glacial cycle, while the Emissions-M scenario attempts to predict the future groundwater conditions at Olkiluoto in the situation where the atmospheric greenhouse gasses delay the next glacial cycle at least for 100,000 years. The groundwater compositions, considered active at the repository depth in future, are judged in this study. Several geochemical processes are considered active at the repository depth. Calculations concentrate on the changes occurring with time within the tunnel unit. All simulations are done in geochemically reducing conditions. It turns out that sulphur cycling in these conditions is in central role considering the safety assessment studies of Olkiluoto repository. Furthermore, groundwater salinity and cation occupancy within the exchange sites of montmorillonite contributes to sealing properties of the engineered barrier system. Calculations attempt to estimate effects of possible future scenarios for the Olkiluoto repository. The results indicate that the buffer capacities assigned to the tunnel unit are large enough, at least to next 100,000 years, to maintain dissolved sulphide contents low in the groundwater infiltrating through the tunnel engineered barrier system. Geochemical reactions raise the bicarbonate levels within the groundwater. This is a useful buffer if low pH conditions emerge in the

Results of Monitoring at Olkiluoto in 2005. Rock Mechanics

International Nuclear Information System (INIS)

Riikonen, S.

2006-08-01

Programme of Monitoring (Posiva 2003 b) was introduced to study Olkiluoto investigation are both during and following the excavation of underground test facility, ONKALO. Programme consists of four main headings: rock mechanics, hydrology and hydrogeology, geochemistry and other types of disturbance. Monitoring programme in year 2005 consist of three fields of research: microseismic measurements, GPS measurements and precise levelling. This report presents Posiva's rock mechanical monitoring programme results from the year 2005. Report has been composed from annual reports of microseismic measurements, GPS measurements and precise levelling by Sanna Riikonen. In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. This report gives the results of microseismic monitoring during the year 2005. Also the changes in the structure and the operation procedure of the network are described. The network has operated nearly continuously. The total duration of network failures has been about 8 hours. Altogether 2159 events have been located in the Olkiluoto area, in reported time period. The magnitudes of the observed events range from ML = -2.1to ML = 1.6 (ML = magnitude in local Richter's scale). Most of them are explosions. Three of the observed events are be classified as microearthquakes. Evidence of activity that would has influence on the safety of the ONKALO, have not found. The GPS based deformation studies has been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. Twenty GPS measurement campaigns have been carried out at Olkiluoto since 1995. According to the time series of the GPS results 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than ± 0.22 mm/a. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. The local velocity components are small but

Results of monitoring at Olkiluoto in 2004. Rock mechanics

International Nuclear Information System (INIS)

Riikonen, S.

2005-09-01

This report presents Posiva Oy's results of the rock mechanical monitoring programme from the year 2004. Monitoring programme was established for long time monitoring of modifications in the bedrock during the excavation of the ONKALO underground research facility stated in Olkiluoto island. This is the first annual report where rock mechanical research work has being reported also from the monitoring point of view. Rock mechanical research work consists of both GPS measurements and microseismic measurements carried out in Olkiluoto island. Both measurements have been performed during several years even before monitoring programme was established. GPS measurements have been carried out since 1995 and microseismic network has operated since 2002. There have been no significant changes in observations when studying rock mechanical results from the year 2004 and comparing them to results from the previous years. Therefore it can be said, that so far ONKALO has barely had any effect on rock mechanics in Olkiluoto. Report has been composed from the annual reports of GPS measurements.(orig.)

Prediction of long-term influence of ONKALO and Korvensuo reservoir on groundwater level and water balance components on Olkiluoto island

International Nuclear Information System (INIS)

Karvonen, T.

2010-08-01

The Olkiluoto surface hydrological model was used to compute the influence of various ONKALO leakage scenarios on changes in groundwater level in overburden soils and hydraulic heads in the bedrock. Moreover, the model effect of ONKALO leakages on water balance components of the Olkiluoto Island (runoff, evapotranspiration, discharge to the sea area through the bedrock and discharge from the Korvensuo reservoir) and on the thickness and area of unsaturated bedrock layer were computed. Leakages into ONKALO lower the groundwater level in overburden soils especially during those years when precipitation is smaller than the long-term average value 550 mm a -1 . According to model results groundwater level can be below sea level if leakage rate into ONKALO is 180 l/min or more. If leakage rate is smaller than 180 l/min groundwater level is above sea level all the time also during dry years. The modelling results show that there are local water divides inside the island both on the southern and northern side of ONKALO at all time points and for all leakage rates. The local water divides ensure that sea water cannot intrude to ONKALO via surface waters. A more detailed version of the Olkiluoto surface hydrological model was developed for the area around the infiltration experiment. Site scale data were available for the location of the most transmissive hydrogeological zones. The analysis of hydraulic responses has shown that there are local connections between different areas around the pumping drillhole OL-KR14. The importance of the local responses was verified by an additional small hydrogeological zone HZInf connecting HZ19A, HZ19C, OL-KR14, OL-PP66, OL-PP68 and OL-PP69 that was added to the model. In future studies it is necessary to describe the local zones explicitly in the model to allow more realistic flow simulations. Discharge has been measured manually in four measuring weirs since March 2003. The old V-shaped measuring weirs were replaced by new automatic

Results of Monitoring at Olkiluoto in 2007. Rock Mechanics

International Nuclear Information System (INIS)

Mattila, J.; Hakala, M.

2008-06-01

Posiva Oy has operated a local microseismic at Olkiluoto network since February 2002. During the monitoring in 2007, altogether 2207 events have been located in the Olkiluoto area, in the reported time period. The magnitudes of the observed events range from ML = -2.1 to 1.5 (ML = magnitude in local Richter's scale). All these events are explosions. Evidence of seismic activity that would have influence on the safety of the ONKALO, have not been observed. One recorded event was a microearthquake of magnitude ML 1.9, which occurred in Laitila, approximately 40 km from Olkiluoto. The GPS based deformation studies have been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. Since then, altogether 24 GPS measurement campaigns have been carried out at Olkiluoto. According to the time series of the GPS results, 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than ± 0.20 mm/a. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. These local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliably determined (maximum velocity is -0.21 mm/a ± 0.02 mm/a) In order to monitor vertical movements at Olkiluoto, precise leveling campaigns of the GPS stations were started in the area in autumn 2003. Since then, leveling campaigns have taken place in 2005 and 2007, including the leveling of the existing GPS network and line from Olkiluoto Island to Lapijoki at the main land. Additional smaller leveling campaigns took place in 2006. The campaign in autumn 2007 consisted of the levellings of all measured and undestroyed points of the earlier campaigns. Compared to the mean theoretical land uplift, the nodal bench mark near the crossing of Olkiluodontie and Satamatie had risen in four years 2.6 mm more than the nodal bench

Results of Monitoring at Olkiluoto in 2010. Rock Mechanics

Energy Technology Data Exchange (ETDEWEB)

Lahti, M [ed.; Siren, T

2011-12-15

The rock mechanical monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The construction of ONKALO is not expected to induce large-scale movements of the rock blocks or affect the rate of isostatic uplift but the evaluation of any tectonic events is important for the safety assessment. The monitoring consists of seismic measurements, GPS measurements and precise levelling campaigns at Olkiluoto and vicinity and extensometer and convergence measurements carried out in ONKALO. Posiva established a local seismic network of six stations on the island of Olkiluoto in 2002. After that the number of seismic stations has increased gradually. In 2010 the permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during 2010.

Results of Monitoring at Olkiluoto in 2010. Rock Mechanics

International Nuclear Information System (INIS)

Lahti, M.; Siren, T.

2011-12-01

The rock mechanical monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The construction of ONKALO is not expected to induce large-scale movements of the rock blocks or affect the rate of isostatic uplift but the evaluation of any tectonic events is important for the safety assessment. The monitoring consists of seismic measurements, GPS measurements and precise levelling campaigns at Olkiluoto and vicinity and extensometer and convergence measurements carried out in ONKALO. Posiva established a local seismic network of six stations on the island of Olkiluoto in 2002. After that the number of seismic stations has increased gradually. In 2010 the permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during 2010

Results of monitoring at Olkiluoto in 2006. Rock mechanics

International Nuclear Information System (INIS)

Mattila, J.

2007-07-01

Posiva Oy has operated a local microseismic at Olkiluto network since February 2002. During the monitoring in 2006, altogether 2041 events have been located in the Olkiluoto area, in the reported time period. The magnitudes of the observed events range from ML = -1.1 to 3.1 (ML = magnitude in local Richter's scale). Most of the events are construction-related explosions but two of them are recorded as microearthquakes. Evidence of seismic activity that would have influence on the safety of the ONKALO, have not been observed. The observed earthquakes that occurred in 2006 were small, with a magnitude of ML -0.6 and ML= -0.9. The earthquakes relate to small movements in brittle deformation zones OL-BFZ043 and OL-BFZ034. Estimated peak slip values of the earthquakes are 14 μm and 4 μm and the source radiuses 11 and 8 meters, respectively. The GPS based deformation studies have been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. Since then, altogether 22 GPS measurement campaigns have been carried out at Olkiluoto. According to the time series of the GPS results, 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than ± 0.22 mm/a. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. These local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliably determined (maximum velocity is -0.23 mm/a ± 0.023 mm/a) (orig.)

Olkiluoto biosphere description 2006

International Nuclear Information System (INIS)

Haapanen, R.; Aro, L.; Ilvesniemi, H.; Kareinen, T.; Kirkkala, T.; Mykrae, S.; Turkki, H.; Lahdenperae, A.-M.; Ikonen, A.T.K.

2007-02-01

This report summarises the current knowledge of the biosphere of Olkiluoto, and it is the first Biosphere Description Report. The elements considered were climate, topography, land use, overburden, terrestrial vegetation and fauna and sea flora, fauna and water. The principal aim was to present a synthesis of the present state (now to 2020) and the main features of past evolution of the biosphere at the site using currently available data. The lack of site specific parameters and their importance was discussed. Conceptual ecosystem models are presented for land and sea. Currently available data made it possible to calculate the biomass of the terrestrial vegetation and further convert it to carbon. In the case of terrestrial animals, preliminary figures are given for moose alone due to lack of sitespecific data. For the same reason, the sea ecosystem model was not quantified within this work. The ecosystems on Olkiluoto do not deviate from the surrounding areas. Since mires are few on Olkiluoto, forests are the most important land ecosystem. However, coastal areas are the transition zones between land and sea, and also potential sites for deep groundwater discharge. The major interest concerning aquatic ecosystems was laid on four future lakes potentially developing from the sea due to the land up-lift. Current sea sediments near Olkiluoto are future land areas, and thus very important. Spatially, the forest ecosystems of Olkiluoto are now most comprehensively covered, while the temporal coverage is highest in sea ecosystems. Lack of data is greatest in terrestrial fauna and sea sediments. During this work, the system boundaries were crossed and the use of data over disciplines was started. The data were mostly in agreement, but some discrepancies were detected. To solve these, and to supplement the existing data, some recommendations were given. (orig.)

Bentonite as a colloid source in groundwaters at Olkiluoto

International Nuclear Information System (INIS)

Vuorinen, U.; Hirvonen, H.

2005-02-01

In this work bentonite was studied as a potential source of colloids in Olkiluoto groundwaters. Samples were collected at two groundwater stations, PVA1 at 37.5 m dept and PVA3 at 95.6 m depth, in the VLJ-tunnel. The deeper groundwater at PVA3 was more saline (2.6g/L of Cl-) than the shallow at PVA1 (0.8g/L of Cl-). A bentonite source had been assembled at each groundwater station so that two sample lines were available for water samples; one for collecting a sample before and the other for collecting a sample after interaction with bentonite. Before starting the actual colloid sampling groundwaters from both sample lines at both stations were analysed. Only minor alterations, mostly within the uncertainty limits of the analysis methods, were brought about in the water chemistries after interaction with the bentonite sources. The only clear changes were seen in the concentration of iron which decreased after interaction with bentonite in the groundwaters at both stations. After groundwater sampling the actual colloid sampling was performed. The water samples were collected and treated inside a movable nitrogen filled glove-box. The samples could be collected from each sampling line directly in the glove-box via two quick-couplings that had been assembled on the front face of the box. The sample lines had been assembled with 0.45 μm filters before entering the glove-box, because only colloids smaller than 0.45 μm were of interest, as they are not prone to sedimentation in slow groundwater flows and therefore could act as potential radionuclide carriers. Colloid samples were collected and treated similarly from both sampling lines at both groundwater stations. For estimating the colloid content the groundwater samples were filtered with centrifugal ultrafiltration tubes of different cut-off values (0.3 μm, 300kD and 10kD). The ultrafiltrations produced the colloid-containing concentrate fractions and the soluble substances-containing filtrate fractions. In

Results of monitoring at Olkiluoto in 2009. Rock mechanics

International Nuclear Information System (INIS)

Lahti, M.; Hakala, M.

2010-09-01

The rock mechanical monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The construction of ONKALO is not expected to induce large-scale movements of the rock blocks or affect the rate of isostatic uplift but the evaluation of any tectonic events is important for the safety assessment. The monitoring consists of seismic measurements, GPS measurements and precise levelling campaigns at Olkiluoto and vicinity and additionally extensometer and convergence measurements carried out in ONKALO. Posiva established a local seismic network of six stations on the island of Olkiluoto in 2002. The number of seismic stations has increased gradually being in 2009 altogether 14. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semi-regional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale. The smaller target area is s called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. All the expected excavation induced events assumingly occur within this volume. At the moment the seismic ONKALO block includes 10 seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. The seismic network has operated continuously in 2009 and during the year altogether 1256 events have been located in the Olkiluoto area. Most of them (1161) are explosions that occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (1135 events)

Installation of groundwater observation tubes OL-PVP30-35 at Olkiluoto in Eurajoki 2009

International Nuclear Information System (INIS)

Toropainen, V.

2009-10-01

In order to widen the Posivas groundwater monitoring network at Olkiluoto, Suomen Malmi Oy (Smoy) to install eight new groundwater observation tubes. The identification numbers of the groundwater observation tubes are OL-PVP30, OL-PVP31A and 31B, OL-PVP32, OL-PVP33, OL-PVP34A and 34B and OL-PVP35. The observation tubes were installed between January 28th and February 17th in 2009. The drilling rig used in the installation work was a GM-200 rig. Drilling equipment consisted of casing tubes (n 90/77 mm) with drilling bit, 55 mm geo rods and 64 mm drilling bits. Monitoring pipes (PVC, n 60/52 mm) were lowered into the holes inside the casings. The monitoring pipes consist of a lower section of riser pipe, a middle section of screen pipe and an upper section of riser pipe. The screen pipe slot size is 0.3 mm and the length of the screen section is one or two metres. Protective stainless steel covers with lock-up caps were installed around the monitoring tubes. In addition to the installation of the tubes, the work included observation of soil/drill cuttings quality during drilling, time-penetration measurements and water level measurements after installation. (orig.)

Electromagnetic Sampo monitoring soundings at Olkiluoto 2010

International Nuclear Information System (INIS)

Korhonen, K.; Korpisalo, A.; Ojamo, H.

2010-12-01

The Geological Survey of Finland has carried out electromagnetic frequency-domain depth soundings at fixed measurement stations in Olkiluoto annually since 2004. The purpose of the soundings is to monitor the groundwater conditions in the vicinity of the ONKALO rock characterization facility which will ultimately be part of the final nuclear waste disposal facility for the Finnish nuclear power companies. A new monitoring survey was carried out at the turn of May-June 2010. The survey resulted in 38 successfully performed soundings at 10 stations. The data set spanning the time period of 2004 to 2010 was interpreted with layered-earth models. Most of the interpretations indicate no systematic changes in the level of deep saline groundwater. However, at one station there are indications of a systematic rise in the groundwater level. (orig.)

Numbers, biomass and cultivable diversity of microbial populations relate to depth and borehole-specific conditions in groundwater from depths of 4-450 m in Olkiluoto, Finland.

Science.gov (United States)

Pedersen, Karsten; Arlinger, Johanna; Eriksson, Sara; Hallbeck, Anna; Hallbeck, Lotta; Johansson, Jessica

2008-07-01

Microbiology, chemistry and dissolved gas in groundwater from Olkiluoto, Finland, were analysed over 3 years; samples came from 16 shallow observation tubes and boreholes from depths of 3.9-16.2 m and 14 deep boreholes from depths of 35-742 m. The average total number of cells (TNC) was 3.9 x 10(5) cells per ml in the shallow groundwater and 5.7 x 10(4) cells per ml in the deep groundwater. There was a significant correlation between the amount of biomass, analysed as ATP concentration, and TNC. ATP concentration also correlated with the stacked output of anaerobic most probable number cultivations of nitrate-, iron-, manganese- and sulphate-reducing bacteria, and acetogenic bacteria and methanogens. The numbers and biomass varied at most by approximately three orders of magnitude between boreholes, and TNC and ATP were positively related to the concentration of dissolved organic carbon. Two depth zones were found where the numbers, biomass and diversity of the microbial populations peaked. Shallow groundwater down to a depth of 16.2 m on average contained more biomass and cultivable microorganisms than did deep groundwater, except in a zone at a depth of approximately 300 m where the average biomass and number of cultivable microorganisms approached those of shallow groundwater. Starting at a depth of approximately 300 m, there were steep gradients of decreasing sulphate and increasing methane concentrations with depth; together with the peaks in biomass and sulphide concentration at this depth, these suggest that anaerobic methane oxidation may be a significant process at depth in Olkiluoto.

Increasing the reliability of the Olkiluoto surface and near-surface hydrological model

International Nuclear Information System (INIS)

Karvonen, T.

2009-05-01

The aim of the study was to improve the reliability of the Olkiluoto surface hydrological model that calculates the overall water balance components of Olkiluoto Island. ONKALO and Korvensuo reservoir were added as explicit structures to the model. The model links the unsaturated and saturated soil water in the overburden and groundwater in bedrock to a continuous pressure system. With the model it is possible to evaluate the influence of water leaking to ONKALO on groundwater level in overburden soils and pressure head in shallow bedrock drillholes. Anisotropy was added to the surface hydrological model and several model runs were carried out using anisotropy factors 1, 5 and 10. Anisotropy factor of 10 is used in the 2008 version of the deep hydrogeological model and the same anisotropy will be used in future calculations of the surface hydrological model to ensure consistency of the parameter values in the two models. The correspondence between measured and computed groundwater levels has been improved due to new soil type delineation and the calibration of the soil water retention curve parameters. Computed groundwater level variation can be characterized by a measure ΔH COMP , which is difference between maximum and minimum value during the calibration period. Average ΔH COMP in groundwater tubes was 1.98 m and the corresponding measured value ΔH MEAS was 2.08 m, i.e. the difference between measured and computed value was around 0.1 m (0.16 m in the 2007 version). Temporal variation (difference between maximum and minimum pressure head) was simulated well also in most of the shallow bedrock drillholes. ONKALO was added to the 2008 version of the Olkiluoto surface hydrological model. Influence of ONKALO is taken into account by giving the total discharge as input data from existing measurements or from calculations of the deep hydrogeological model of the Olkiluoto Island. The computed results show that ONKALO has a temporal effect on groundwater level in

Results of monitoring at Olkiluoto in 2012. Rock mechanics

International Nuclear Information System (INIS)

Johansson, E.; Siren, T.

2014-01-01

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2012 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations carried out in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 22 triaxial sensors. Six stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2012. The number of located events was much smaller in 2012 than during the previous years due to the interruption of the excavation. Altogether 337 events were located in the Olkiluoto area of which about half (181) were explosions. Two excavation induced earthquakes were observed at -420 m level and were associated with a known tunnel crosscutting fracture. According to the seismic monitoring the rock mass has been stable in 2012. The local GPS network consists of 19 stations. The whole network was measured twice in 2012. Most of the inner network baselines showed very small motions as in the previous years: 80 % of change rates were smaller than 0.10 mm/a. Roughly one third of the change rates are statistically significant. One baseline was also measured using electronic distance measurements (EDM) and the results fitted well to the times series. The surface levelling network currently consists of 87 fixed measuring points. During 2012 only measuring loops VLJ, ONKALO and Olkiluoto Strait were measured. The results indicated that vertical deformations were small compared to 2011 results. The largest deformations around 0.6 mm upwards existed above the VLJ-repository. The displacement measurements in 2012 consisted of the extensometer measurements in the technical rooms of the ONKALO. Readings were taken continuously once a hour by a

Results of monitoring at Olkiluoto in 2011. Hydrogeochemistry

International Nuclear Information System (INIS)

Penttinen, T.; Partamies, S.; Lahdenperae, A.-M.; Ahokas, T.; Lamminmaeki, T.; Lehtinen, A.

2014-03-01

The construction work of underground research facility ONKALO started in the June 2004. Possible changes caused by the construction of the disposal facility in the chemical environment in shallow and deep groundwaters are monitored on a regular basis. This report presents the hydrogeochemical monitoring measurements and observations made in 2011. A total of 56 shallow groundwater monitoring samples were taken in 2011 (36 monitoring and 56 infiltration area). The pH values varied from acidic (5.7) to slightly alkaline (7.9). In OL-PVP18A, TDS remained still at the high level as well as the sulphate concentration. In OL-PVP17, OL-PVP4A and OL-PP2 is still observed slightly increased sulphate concentrations. Seasonal fluctuation has been observed in OL-PVP18A, OL-PVP20, OL-PVP31A and OL-PP39. A slightly upward trend in TDS has been observed near the Olkiluoto Natura area (and the old forests preservation area) in OL-PVP4A and OL-PP2. Twenty-two deep groundwater samplings were carried out in 13 different drillholes and altogether 43 groundwater samples from ONKALO during the year 2011. The results from ground surface showed some indications of changes in groundwater compositions, which can be connected to high hydraulic gradient of ONKALO or to joint effect of the ONKALO and an open drillhole. The results in sampling sections of OL-KR25 showed dilution due to the leak in packering systems in OL-KR28. The results in two monitoring sections OL-KR25 T 91 and OL-KR25 T 337 3 showed also heavy stable isotopic composition, which indicate some input of Korvensuo water. The sample from OL-KR37 T 165 continued dilution trend, which is significant and supports the earlier observations. Salinity of section OL-KR9 T 468 has recovered from previous sampling in 2009. The results of samples of fractures with low transmissivity are rather similar to the baseline data. However, slightly less saline characteristics were observed in very low transmissive fractures of ONK-PP262 and ONK

Results of monitoring at Olkiluoto in 2007. Environment

International Nuclear Information System (INIS)

Haapanen, R.

2008-06-01

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2007. These summary reports have been published since 2005 (target year 2004). The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground characterization facility. Although some of the nuclear power production related monitoring studies by TVO (the power company) have been going on from the 1970s, the repository-related environmental monitoring of Olkiluoto Island has only recently been comprehensive. In the monitoring data, the ongoing construction work (OL3, ONKALO and related infrastructure) is seen for instance in raised noise levels and deposition of base cations and iron. The land-use continues to change, but where there is natural environment, it resembles other coastal locations. The nearby marine environment is affected by the cooling water from the nuclear power plant. (orig.)

Modelling of groundwater flow and solute transport in Olkiluoto. Update 2008

International Nuclear Information System (INIS)

Loefman, J.; Pitkaenen, P.; Meszaros, F.; Keto, V.; Ahokas, H.

2009-10-01

Posiva Oy is preparing for the final disposal of spent nuclear fuel in the crystalline bedrock in Finland. Olkiluoto in Eurajoki has been selected as the primary site for the repository, subject to further detailed characterisation which is currently focused on the construction of an underground rock characterisation and research facility (the ONKALO). An essential part of the site investigation programme is analysis of the deep groundwater flow by means of numerical flow modelling. This study is the latest update concerning the site-scale flow modelling and is based on all the hydrogeological data gathered from field investigations by the end of 2007. The work is divided into two separate modelling tasks: 1) characterization of the baseline groundwater flow conditions before excavation of the ONKALO, and 2) a prediction/outcome (P/O) study of the potential hydrogeological disturbances due to the ONKALO. The flow model was calibrated by using all the available data that was appropriate for the applied, deterministic, equivalent porous medium (EPM) / dual-porosity (DP) approach. In the baseline modelling, calibration of the flow model focused on improving the agreement between the calculated results and the undisturbed observations. The calibration resulted in a satisfactory agreement with the measured pumping test responses, a very good overall agreement with the observed pressures in the deep drill holes and a fairly good agreement with the observed salinity. Some discrepancies still remained in a few single drill hole sections, because the fresh water infiltration in the model tends to dilute the groundwater too much at shallow depths. In the P/O calculations the flow model was further calibrated by using the monitoring data on the ONKALO disturbances. Having significantly more information on the inflows to the tunnel (compared with the previous study) allowed better calibration of the model, which allowed it to capture very well the observed inflow, the

Simulation of hydraulic disturbances caused by the underground rock characterisation facility in Olkiluoto, Finland

International Nuclear Information System (INIS)

Loefman, J.; Ferenc, M.

2004-01-01

Spent fuel from the Finnish nuclear power plants will be disposed of in a repository to be excavated in crystalline bedrock at a depth of 400-700 metres in Olkiluoto. The extensive site investigations carried out since the early 1980's will next focus on the construction of an underground rock characterisation facility (ONKALO) in 2004-2010. The open tunnel system will constitute a major hydraulic disturbance for the site's groundwater conditions for hundreds of years. Especially, inflow of groundwater into the tunnels results in a drawdown of groundwater table and upcoming of deep saline groundwater, which the present study aimed to assess by means of a 3D finite element simulation. The modelled bedrock volume, which horizontally covered the whole Olkiluoto island, was conceptually divided into hydraulic units, planar fracture zones and sparsely fractured rock between the zones, which were both separately treated as porous media. The geometry of the fracture zones was based on the geological bedrock model. Simulations showed that without engineering measures (e.g. grouting) taken to limit inflow of groundwater into the open tunnels, the hydraulic disturbances could be drastic. The tunnels draw groundwater from all directions in the bedrock. A major part of inflow comes from the well-conductive subhorizontal fracture zones intersected by the access tunnel and the shaft. The simulations show that the resulting drawdown of groundwater table may be from tens to hundreds of metres and the depressed area may extend over the area of the island. The results also indicate that the salinity of groundwater is gradually rising around and below the tunnel system, and locally concentration (TDS) may rise rather high in the vicinity of the tunnels. However, the disturbances can significantly be reduced by the grouting of rock. (orig.)

Ground water chemistry and water-rock interaction at Olkiluoto

International Nuclear Information System (INIS)

Pitkaenen, P.; Front, K.

1992-02-01

Bedrock investigations for the final repository for low- and intermediate level wastes (VLJ repository) generated at the Olkiluoto (TVO-I and TVO-II) nuclear power plant, stareted in 1980. Since 1988 the area has been investigated for the final disposal of spent nuclear fuel. In the report the geochemistry at the nuclear waste investigation site, Olkiluoto, is evaluated. The hydrogeological data are collected from boreholes drilled down to 1000-m depth into Proterozoic crystalline bedrock. The interpretation is based on groundwater chemistry and isotope data, mineralogical data, and the structure and hydrology of the bedrock, using correlation diagrams and thermodynamic calculations (PHREEQE). The hydrogeochemistry and major processes controlling the groundwater chemistry are discussed. The groundwater types are characterized by water-rock interaction but they also show features of other origins. The fresh and brackish waters are contaminated by varying amounts of young meteoric water and brackish seawater. The saline water contains residues of possibly ancient hydrothermal waters, imprints of which are occasionally seen in the rock itself. Different mixing phenomenas are indicated by the isotope contents (O-l8/H-2, H-3) and the Ca/Cl, Na/Cl, HCO 3 /Cl, SO 4 /Cl, Br/Cl, SI(calcite)/SI(dolomite) ratios. The interaction between bedrock and groundwater is reflected by the behaviour of pH, Eh, Ca, Mg, Na, K, Fe, HCO 3 and S0 4 . Dissolution and precipitation of calcite and pyrite, and aluminosilicate hydrolysis play the major role in defining the groundwater composition of the above components

Interpretation of electromagnetic Sampo monitoring soundings of Olkiluoto

International Nuclear Information System (INIS)

Korhonen, K.

2010-04-01

The Geological Survey of Finland (GTK) has carried out electromagnetic Sampo soundings at Olkiluoto annually since 2004 commissioned by Posiva. The soundings have been carried out at the same measurement stations every year. The goal of the soundings is to detect any changes in the electrical conditions of the bedrock surrounding the ONKALO underground research facility. This study aims to detect possible changes in the groundwater conditions using modelling. The sensitivity of the Sampo method to changes in the electrical properties and the level of groundwater were investigated as part of this study. The results of the sensitivity investigation indicate that the Sampo method is capable of detecting changes occurring even quite deep in the bedrock. Thus, the usage of the Sampo method to monitor the groundwater conditions is warranted. The plots of apparent resistivity as a function of depth indicate that the area directly above the ONKALO facility is very disturbed electromagnetically. However, most of the soundings to the east and west of ONKALO are of better quality and were interpreted. The results indicate possible changes in the groundwater conditions. The level of saline groundwater may be sinking in the eastern part while it may be rising on the western part. (orig.)

Olkiluoto site description 2008. Part 1

International Nuclear Information System (INIS)

2009-04-01

This third version of the Olkiluoto Site Report, produced by the OMTF (Olkiluoto Modelling Task Force), updates the Olkiluoto Site Report 2006 (Andersson et al. 2007) with the data and knowledge obtained up to December 2007. The main product of the modelling has been to develop an updated version of the descriptive model of the site (the Site Descriptive Model), i.e. a model describing the geometry, properties of the bedrock and the water and the associated interacting processes and mechanisms. The Site Descriptive Model is divided into six parts: the surface system, geology, rock mechanics, hydrogeology, hydrogeochemistry and migration, which are presented in individual chapters. Five separated models are presented: the geological, rock mechanics, hydrogeological, hydrogeochemical and migration models. The main advances since Site Report 2006 are: (1) The geological model has been revised according to new data and interpretations. This has improved the consistency between the locations of the deformation zones in the geological model and the hydraulic zones in the hydrogeological model, (2) New 3D seismic data have been incorporated within the geological model and an initial model for the eastern part of the Island is presented. Site-scale brittle deformation zones are extrapolated to intersect the surrounding regional lineaments, unless prohibited by direct observations to the contrary. The alteration model has been revised, showing a clear correspondence between the illitisation and the sitescale fault zones, (3) A first account of the development of the brittle deformation history of the site is provided, (4) A new geological DFN model has been developed, that considers mapped fracture traces from both the surface and the ONKALO, (5) A new stress state model and fracture and fracture zone properties are presented, (6) A new hydrogeological DFN model has been developed, (7) An updated site scale (EPM) flow model has been developed, (8) There has been an

Results of Monitoring at Olkiluoto in 2006. Environment

International Nuclear Information System (INIS)

Haapanen, R.

2007-07-01

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2006. This is the third annual report. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground characterization facility. Although some of the nuclear power production related monitoring studies by TVO (the power company) have been going on from the 1970s, the repository-related environmental monitoring of Olkiluoto Island has only recently been comprehensive. Consequently, the first Biosphere Description Report was written in 2006. This work further produced some analyses belonging to the environmental monitoring programme, namely the estimates of biomass in terrestrial vegetation (forests) and a preliminary estimate of the biomass in terrestrial fauna (moose). In the monitoring data, the ongoing construction work (OL3, ONKALO and related infrastructure) is seen for instance in raised noise levels and deposition of base cations and iron. The land-use continues to change, but where there is natural environment, it resembles other coastal locations. The nearby marine environment is affected by the cooling water from the nuclear power plant. (orig.)

GPS operations at Olkiluoto in 2009

Energy Technology Data Exchange (ETDEWEB)

Kallio, U.; Nyberg, S.; Koivula, H.; Jokela, J.; Poutanen, M.; Ahola, J. (Finnish Geodetic Institute, Masala (Finland))

2010-06-15

The GPS based deformation studies have been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. One pillar in the investigation area belongs to the Finnish permanent GPS network, FinnRef. 28 GPS measurement campaigns have been carried out at Olkiluoto since 1995. According to the time series of the GPS results 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than +-0.20 mm/a. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. These local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliably determined. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured using EDM instruments in connection to the GPS observations. Changes in he difference between the GPS and EDM results indicate the systematic change in GPS results. No corrections based on only one baseline were not applied to GPS vectors. The GPS network at Olkiluoto was extended in 2003. The new pillars were built close to Kuivalahti village and on a small island of Iso Pyrekari. According to the geological evidence it is expected that a fracture zone is located between the new stations, thus enabling the determination of possible deformations along the fracture zone. The new pillars have been observed since 2003 and now we have computed the first deformation analysis from the six years data. Four new permanent stations will be established in summer 2010 at Olkiluoto. We have automated the processing of the campaign data by using the Bernese processing engine (BPE) together with our own Perl scripts. The local crustal deformations have been studied in GeoSatakunta project, too. This GPS network is located in Cities of Pori and Rauma and their neighbouring municipalities. Two new pillars

GPS operations at Olkiluoto in 2009

International Nuclear Information System (INIS)

Kallio, U.; Nyberg, S.; Koivula, H.; Jokela, J.; Poutanen, M.; Ahola, J.

2010-06-01

The GPS based deformation studies have been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. One pillar in the investigation area belongs to the Finnish permanent GPS network, FinnRef. 28 GPS measurement campaigns have been carried out at Olkiluoto since 1995. According to the time series of the GPS results 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than ±0.20 mm/a. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. These local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliably determined. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured using EDM instruments in connection to the GPS observations. Changes in he difference between the GPS and EDM results indicate the systematic change in GPS results. No corrections based on only one baseline were not applied to GPS vectors. The GPS network at Olkiluoto was extended in 2003. The new pillars were built close to Kuivalahti village and on a small island of Iso Pyrekari. According to the geological evidence it is expected that a fracture zone is located between the new stations, thus enabling the determination of possible deformations along the fracture zone. The new pillars have been observed since 2003 and now we have computed the first deformation analysis from the six years data. Four new permanent stations will be established in summer 2010 at Olkiluoto. We have automated the processing of the campaign data by using the Bernese processing engine (BPE) together with our own Perl scripts. The local crustal deformations have been studied in GeoSatakunta project, too. This GPS network is located in Cities of Pori and Rauma and their neighbouring municipalities. Two new pillars

Groundwater sampling at Olkiluoto, Eurajoki from the borehole OL-KR6 during a long-term pumping test in 2006

International Nuclear Information System (INIS)

Hirvonen, H.; Hatanpaeae, E.; Ahokas, H.

2007-05-01

A long-term pumping test at borehole OL-KR6 at Olkiluoto was initiated in 2001. Since then, flow and in situ EC measurements as well as groundwater sampling from specific sampling sections have been performed yearly. The aim of this study was to obtain information on the potential connections via fractures both to the sea and to deep saline groundwater during long-term pumping of the open borehole. In 2006, four groundwater samples were collected from four different sampling depths (98.5-100.5 m, 125-130 m, 135-137 m and 422-425 m). The groundwater samples were taken in stages using PAVE equipment. The water types found in the groundwater samples from OL-KR6 were Na-Ca-Cl (for samples from depths of 98.5-100.5 m and 125-130 m) and Na-Cl (for samples from depths of 135-137 m and 422-425 m). The sample from depth 422-425 m was saline (TDS> 10000 mg/l), while other waters were brackish (1000 mg < TDS <10000 mg/l). This study presents the sampling methods and analysis results of groundwater samples from deep borehole OL-KR6, and draws a comparison between the results of the in situ EC measurements and the EC results measured during groundwater sampling. This report also contains a short comparison of the results obtained from the long-term pumping test conducted between 2001-2006. In situ EC results and EC results measured in laboratory are in quite good agreement. At sampling depth, 422-425 m, EC increased between 2004-2006. At a depth of 423 m, much variation in situ EC-values indicates that routes of groundwater may change during long-term pumping due to the limited storages of different aquifers or the heterogeneity of the content of groundwater in different locations in the bedrock. The minor systematic difference between in situ and sampling EC at a depth of 136 m was probably due to the different flow fields during flow logging and water sampling. The dominant gas in the groundwater samples was nitrogen. Carbon dioxide was the second dominant gas, except for the

Results of monitoring at Olkiluoto in 2008. Environment

International Nuclear Information System (INIS)

Haapanen, A.

2009-09-01

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2008. These summary reports have been published since 2005 (target year 2004). The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground characterization facility. Although some of the nuclear power production related monitoring studies by TVO (the power company) have been going on from the 1970s, the repository-related environmental monitoring of Olkiluoto Island has only recently been comprehensive. However, the monitoring programme evolves according to experiences from modelling work and increasing knowledge of most important site data. For example, in addition to the originally planned activities, in 2008 several studies on fauna were carried out, some soil and vegetation transects running from land to sea were established, a separate survey of water quality with automatic detectors was carried out and zooplankton and organic carbon studies were started in context of sea monitoring. In the monitoring data, the ongoing construction work (OL3, ONKALO and related infrastructure) is seen for instance in raised levels of noise and some deposited elements. The land-use continues to change, but where there is natural environment is affected by the cooling water from the nuclear power plant. (orig.)

Olkiluoto 3 Experience

International Nuclear Information System (INIS)

Tiippana, Petteri

2011-01-01

This paper discusses the experience from the Olkiluoto 3 nuclear power plant project from regulator's point of view. There are certain factors that have affected greatly the project progress. First, Olkiluoto 3 nuclear power plant is the first European Pressurised Reactor (EPR) being constructed. Secondly, construction of the unit started after a fairly long break in nuclear power plant construction in Europe, which had resulted in loss of experienced and qualified engineering and manufacturing resources. These factors have to be kept in mind when evaluating the experience from Olkiluoto 3. Experience discussed in this paper have to do with the licensing and regulatory oversight process, completion of the design prior to construction, experience and know-how of the participating organisations, quality management in a nuclear construction project, advanced manufacturing and construction technologies, turnkey contract with regard to licensee's responsibility, safety culture aspects in a nuclear construction project, and the role and importance of regulator's oversight. (author)

Results of monitoring at Olkiluoto in 2010 - Environment

Energy Technology Data Exchange (ETDEWEB)

Haapanen, A. (ed.) [Haapanen Forest Consulting, Vanhakylae (Finland)

2011-10-15

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2010. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground rock characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to experiences gained from the modelling work and increased understanding of the site. Augmentations in 2010 include one previously unmonitored private drilled well, and sampling of crop plants, aquatic macrophytes, and bottom fauna, as well as soil and water in order to obtain more data on site-specific concentration ratios. In addition to Olkiluoto Island, two so called reference lakes have been included in the sampling. Studies have been going on on one reference mire, as well. Bottom fauna studies of River Eurajoki exist from late 1970s, but have not been presented here before. Dust produced during construction of the third nuclear power unit (OL3), ONKALO and related infrastructure can be seen in the analysis results of needle litter. The construction works and road traffic have a raising effect on the noise levels of the immediate surroundings. The land-use continues to change, but the remaining natural environment resembles other coastal locations. The young age of the soils and the closeness of the sea are reflected in the soil properties. Mammalian fauna on the island is typical of coastal

Results of monitoring at Olkiluoto in 2010 - Environment

International Nuclear Information System (INIS)

Haapanen, A.

2011-10-01

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2010. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground rock characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to experiences gained from the modelling work and increased understanding of the site. Augmentations in 2010 include one previously unmonitored private drilled well, and sampling of crop plants, aquatic macrophytes, and bottom fauna, as well as soil and water in order to obtain more data on site-specific concentration ratios. In addition to Olkiluoto Island, two so called reference lakes have been included in the sampling. Studies have been going on on one reference mire, as well. Bottom fauna studies of River Eurajoki exist from late 1970s, but have not been presented here before. Dust produced during construction of the third nuclear power unit (OL3), ONKALO and related infrastructure can be seen in the analysis results of needle litter. The construction works and road traffic have a raising effect on the noise levels of the immediate surroundings. The land-use continues to change, but the remaining natural environment resembles other coastal locations. The young age of the soils and the closeness of the sea are reflected in the soil properties. Mammalian fauna on the island is typical of coastal areas in

Olkiluoto surface and near-surface hydrological modelling in 2010

International Nuclear Information System (INIS)

Karvonen, T.

2011-08-01

The modeling approaches carried out with the Olkiluoto surface hydrological model (SHYD) include palaeohydrological evolution of the Olkiluoto Island, examination of the boundary condition at the geosphere-biosphere interface zone, simulations related to infiltration experiment, prediction of the influence of ONKALO on hydraulic head in shallow and deep bedrock and optimisation of the shallow monitoring network. A so called short-term prediction system was developed for continuous updating of the estimated drawdowns caused by ONKALO. The palaeohydrological simulations were computed for a period starting from the time when the highest hills on Olkiluoto Island rose above sea level around 2 500 years ago. The input data needed in the model were produced by the UNTAMO-toolbox. The groundwater flow evolution is primarily driven by the postglacial land uplift and the uncertainty in the land uplift model is the biggest single factor that influences the accuracy of the results. The consistency of the boundary condition at the geosphere-biosphere interface zone (GBIZ) was studied during 2010. The comparison carried out during 2010 showed that pressure head profiles computed with the SHYD model and deep groundwater flow model FEFTRA are in good agreement with each other in the uppermost 100 m of the bedrock. This implies that flux profiles computed with the two approaches are close to each other and hydraulic heads computed at level z=0 m with the SHYD can be used as head boundary condition in the deep groundwater flow model FEFTRA. The surface hydrological model was used to analyse the results of the infiltration experiment. Increase in bedrock recharge inside WCA explains around 60-63 % from the amount of water pumped from OL-KR14 and 37-40 % of the water pumped from OL-KR14 flows towards pumping section via the hydrogeological zones. Pumping from OL-KR14 has only a minor effect on heads and fluxes in zones HZ19A and HZ19C compared to responses caused by leakages into

Olkiluoto hydrogeochemistry. A 3-D modelling approach for sparce data set

International Nuclear Information System (INIS)

Luukkonen, A.; Partamies, S.; Pitkaenen, P.

2003-07-01

Olkiluoto at Eurajoki has been selected as a candidate site for final disposal repository for the used nuclear waste produced in Finland. In the long term safety assessment, one of the principal evaluation tools of safe disposal is hydrogeochemistry. For assessment purposes Posiva Oy excavates in the Olkiluoto bedrock an underground research laboratory (ONKALO). The complexity of the groundwater chemistry is characteristic to the Olkiluoto site and causes a demand to examine and visualise these hydrogeochemical features in 3-D together with the structural model. The need to study the hydrogeochemical features is not inevitable only in the stable undisturbed (pre-excavational) conditions but also in the disturbed system caused by the construction activities and open-tunnel conditions of the ONKALO. The present 3-D approach is based on integrating the independently and separately developed structural model and the results from the geochemical mixing calculations of the groundwater samples. For spatial geochemical regression purposes the study area is divided into four primary sectors on the basis of the occurrence of the samples. The geochemical information within the four primary sector are summed up in the four sector centroids that sum-up the depth distributions of the different water types within each primary sector area. The geographic locations of the centroids are used for secondary division of the study area into secondary sectors. With the aid of secondary sectors spatial regressions between the centroids can be calculated and interpolation of water type fractions within the centroid volume becomes possible. Similarly, extrapolations outside the centroid volume are possible as well. The mixing proportions of the five detected water types in an arbitrary point in the modelling volume can be estimated by applying the four centroids and by using lateral linear regression. This study utilises two separate data sets: the older data set and the newer data set. The

Results of forest monitoring on Olkiluoto island in 2009

Energy Technology Data Exchange (ETDEWEB)

Aro, L.; Helmisaari, H.S.; Hoekkae, H.; Lindroos, A.-J.; Rautio, P.; Derome, J. (Finnish Forest Research Institute, Vantaa (Finland))

2010-11-15

Forest investigations carried out on Olkiluoto aim to monitor the state of the forest ecosystems, quantify Olkiluoto-specific processes taking place in the forests producing input data for the safety assessment of spent nuclear fuel disposal, and follow possible changes in the forest condition resulting from the intensive construction activities currently being carried out in the area. The forest investigations form a part of the monitoring programme being carried out on Olkiluoto Island under the management of Posiva Oy. This report focuses on activities performed on bulk deposition and forest intensive monitoring plots (MRK and FIP plots) in 2009. In general, the deposition levels in 2009 in the open area and in stand throughfall were quite comparable to those in earlier years, although sulphur and calcium depositions were somewhat higher in the open area than in earlier years. The soil solution quality in 2009 was also quite comparable to that in earlier years. The NH{sub 4}-N and NO{sub 3}-N concentrations were low at all depths in the mineral soil of the FIP plots. There appeared to be a gradual decrease in sulphate concentrations in the mineral soil during the monitoring period. In 2009 the monthly level of transipiration in the Scots pine dominated stand was comparable to previous years (2007-2008). Instead, monthly transpiration in the Norway spruce dominated stand was clearly lower in 2009 than in 2007-2008. Annual total litterfall production was smaller in 2008 than in 2007. The most notable differences between the plots were detected in Al and N concentrations. The Al concentration was higher in living pine needles than in spruce needles. High Al and Fe concentrations were found in remaining litter, and are most likely due to soil dust. The average defoliation level of the pines was 4.6 % and of the spruces 24.1 %, indicating a good crown condition: the pines were classified as non-defoliated and the spruces as slightly defoliated. The minirhizotrone

Results of forest monitoring on Olkiluoto island in 2009

International Nuclear Information System (INIS)

Aro, L.; Helmisaari, H.S.; Hoekkae, H.; Lindroos, A.-J.; Rautio, P.; Derome, J.

2010-11-01

Forest investigations carried out on Olkiluoto aim to monitor the state of the forest ecosystems, quantify Olkiluoto-specific processes taking place in the forests producing input data for the safety assessment of spent nuclear fuel disposal, and follow possible changes in the forest condition resulting from the intensive construction activities currently being carried out in the area. The forest investigations form a part of the monitoring programme being carried out on Olkiluoto Island under the management of Posiva Oy. This report focuses on activities performed on bulk deposition and forest intensive monitoring plots (MRK and FIP plots) in 2009. In general, the deposition levels in 2009 in the open area and in stand throughfall were quite comparable to those in earlier years, although sulphur and calcium depositions were somewhat higher in the open area than in earlier years. The soil solution quality in 2009 was also quite comparable to that in earlier years. The NH 4 -N and NO 3 -N concentrations were low at all depths in the mineral soil of the FIP plots. There appeared to be a gradual decrease in sulphate concentrations in the mineral soil during the monitoring period. In 2009 the monthly level of transipiration in the Scots pine dominated stand was comparable to previous years (2007-2008). Instead, monthly transpiration in the Norway spruce dominated stand was clearly lower in 2009 than in 2007-2008. Annual total litterfall production was smaller in 2008 than in 2007. The most notable differences between the plots were detected in Al and N concentrations. The Al concentration was higher in living pine needles than in spruce needles. High Al and Fe concentrations were found in remaining litter, and are most likely due to soil dust. The average defoliation level of the pines was 4.6 % and of the spruces 24.1 %, indicating a good crown condition: the pines were classified as non-defoliated and the spruces as slightly defoliated. The minirhizotrone images

Modelling of salt water upconing in Olkiluoto

International Nuclear Information System (INIS)

Loefman, J.; Poteri, A.; Pitkaenen, P.

2010-04-01

Posiva Oy is preparing for the final disposal of spent nuclear fuel in the crystalline bedrock in Finland. Olkiluoto in Eurajoki has been selected as the primary site for the repository, subject to further detailed characterisation, which is currently focused on the construction of an underground rock characterisation and research facility (the ONKALO). During the repository operation the open tunnels and shafts of the ONKALO, and the subsequent repository, are likely to create a hydraulic disturbance to the site's groundwater system for hundreds of years (the greatest impact concerns only the time of the operational period, i.e., c. 100 years). In particular, during the operational phase of the repository upward flow below the tunnels may give rise to the upconing of deep highly saline groundwater up to the planned repository rock volume, which is a concern with regard to the performance of the tunnel backfill material after the closure of the tunnels. This study concerns the supporting groundwater flow analysis for the Rock Suitability Criteria (RSC) programme, which has been set up to develop host rock requirements for the repository design and layout adaptation. The objective is to assess the potential upconing of deep highly saline groundwater into the planned repository rock volume. The work is divided into three separate sub-tasks: characterization of the expected upconing on the basis of 1) observations in the drillholes, 2) numerical groundwater flow modelling, and 3) the analytic groundwater flow modelling

Engineering rock mass classification of the Olkiluoto investigation site

Energy Technology Data Exchange (ETDEWEB)

Aeikaes, K. [ed.; Hagros, A.; Johansson, E. [Saanio and Riekkola Consulting Engineers, Helsinki (Finland)] [and others

2000-06-01

Olkiluoto in Eurajoki is being investigated as a possible site for the final disposal of spent nuclear fuel from the Finnish nuclear power plants. The selection of the depth, placement and layout of the repository is affected by the constructability of the bedrock. The constructability, in turn, is influenced by several properties of the host rock, such as its Ethology, the extent of fracturing, its hydrogeological properties and rock engineering characteristics and also by the magnitude and orientation of the in situ stresses and the chemistry of the groundwater. The constructability can be evaluated by the application of a rock classification system in which the properties of the host rock are assessed against common rock engineering judgements associated with underground construction. These judgements are based partly on measurements of in situ stresses and the properties of the bedrock determined from rock samples, but an important aspect is also the practical experience which has been gained during underground excavation in similar conditions and rock types. The aim of the engineering rock mass classification was to determine suitable bedrock volumes for the construction of the repository and has used data from the site characterisation programme carried out at Olkiluoto, which consisted of both surface studies and borehole investigations. The classification specifies three categories of constructability - normal, demanding and very demanding. In addition, rock mass quality has also been classified according to the empirical Q-system to enable a comparison to be made. The rock mass parameters that determine the constructability of the bedrock at Olkiluoto depend primarily on the depth and the Ethology, as well as on whether construction takes place in intact or in fractured rock. The differences in the characteristics of intact rock within a single rock type have been shown to be small. The major lithological unit at Olkiluoto, the mica gneiss, lies in the

Final disposal of spent nuclear fuel in Finnish bedrock. Olkiluoto site report

Energy Technology Data Exchange (ETDEWEB)

Anttila, P. [Fortum Engineering Oy, Vantaa (Finland); Ahokas, H. [Fintact Oy, Helsinki (Finland); Front, K. [VTT Communication and Infrastructure, Espoo (Finland)] [and others

1999-06-01

Posiva Oy is studying the Finnish bedrock for the geological disposal of spent nuclear fuel. The study is based on the site selection research programme started originally in 1983. The programme is in accordance with the decision in principle by the Council of State in 1983 and aims at the selection of one site in 2000. Four sites, Haestholmen in Loviisa, Kivetty in Aeaenekoski, Olkiluoto in Eurajoki and Romuvaara in Kuhmo, have been studied in detail. This report summarises the results of the site investigations carried out at Olkiluoto. The bedrock of the Olkiluoto site consists of Svecofennian metasediments and platonic rocks, 1800-1900 million years in age. Migmatitic mica gneiss is the most abundant rock type, and is intruded by foliated tonalites and granodiorites and massive coarse-grained granites and pegmatites. Five successive plastic deformation phases have been defined. In total, 30 bedrock structures (R-structures) have been modelled at the site. Most of these represent steeply dipping fracture zones, but several sub-horizontal zones, gently dipping to the SE, have also been identified. The rock mass between the fracture zones represents what is termed `intact rock`, which is typically hard, unweathered and sparsely fractured. The R-structures are generally hydraulically more conductive than the intact rock and their mean transmissivity is 3 x 10{sup -7} m{sup 2}/s. The corresponding mean of the hydraulic conductivity values for the intact rock measured using a 2 m packer interval, is 8 x 10{sup -13} m/s, if a lognormal distribution for all measured values is assumed. A clear decrease in hydraulic conductivity with depth has been found for the intact rock, and there seems to be a parallel decrease in the transmissivity of structures. In addition, the hydraulically conductive fractures seem to be more frequent and their transmissivities higher in the uppermost 100 - 200 m of the bedrock than at greater depths. The groundwater chemistry reflects the

Final disposal of spent nuclear fuel in Finnish bedrock. Olkiluoto site report

International Nuclear Information System (INIS)

Anttila, P.; Ahokas, H.; Front, K.

1999-06-01

Posiva Oy is studying the Finnish bedrock for the geological disposal of spent nuclear fuel. The study is based on the site selection research programme started originally in 1983. The programme is in accordance with the decision in principle by the Council of State in 1983 and aims at the selection of one site in 2000. Four sites, Haestholmen in Loviisa, Kivetty in Aeaenekoski, Olkiluoto in Eurajoki and Romuvaara in Kuhmo, have been studied in detail. This report summarises the results of the site investigations carried out at Olkiluoto. The bedrock of the Olkiluoto site consists of Svecofennian metasediments and platonic rocks, 1800-1900 million years in age. Migmatitic mica gneiss is the most abundant rock type, and is intruded by foliated tonalites and granodiorites and massive coarse-grained granites and pegmatites. Five successive plastic deformation phases have been defined. In total, 30 bedrock structures (R-structures) have been modelled at the site. Most of these represent steeply dipping fracture zones, but several sub-horizontal zones, gently dipping to the SE, have also been identified. The rock mass between the fracture zones represents what is termed 'intact rock', which is typically hard, unweathered and sparsely fractured. The R-structures are generally hydraulically more conductive than the intact rock and their mean transmissivity is 3 x 10 -7 m 2 /s. The corresponding mean of the hydraulic conductivity values for the intact rock measured using a 2 m packer interval, is 8 x 10 -13 m/s, if a lognormal distribution for all measured values is assumed. A clear decrease in hydraulic conductivity with depth has been found for the intact rock, and there seems to be a parallel decrease in the transmissivity of structures. In addition, the hydraulically conductive fractures seem to be more frequent and their transmissivities higher in the uppermost 100 - 200 m of the bedrock than at greater depths. The groundwater chemistry reflects the postglacial

The geology of the Olkiluoto area

International Nuclear Information System (INIS)

Anttila, P.; Paulamaeki, S.; Lindberg, A.; Paananen, M.; Koistinen, T.; Front, K.; Pitkaenen, P.

1992-12-01

Teollisuuden Voima Oy (TVO) is preparing for the final disposal of spent nuclear fuel from the Olkiluoto nuclear power plant deep in the Finnish bedrock. An area close to the power plant at Olkiluoto, Eurajoki, was one of the five areas selected in 1987 for the preliminary site investigations. A summary of the geological conditions at the Olkiluoto site is presented in the report

Results of forest monitoring on Olkiluoto island in 2010

International Nuclear Information System (INIS)

Aro, L.; Huhta, A.-P.; Hoekkae, H.; Lindroos, A.-J.; Rautio, P.; Helmisaari, H.-S.

2011-11-01

Forest investigations carried out on Olkiluoto aim to monitor the state of the forest ecosystems, quantify Olkiluoto-specific processes taking place in the forests producing input data for the safety assessment of spent nuclear fuel disposal, and follow possible changes in the forest condition resulting from the intensive construction activities currently being carried out in the area. The forest investigations form a part of the monitoring programme being carried out on Olkiluoto Island under the management of Posiva Oy. This report focuses on activities performed on bulk deposition and forest intensive monitoring plots (MRK and FIP plots) in 2010. In general, the deposition levels in 2010 in the open area and in stand throughfall were quite comparable to those in earlier years, although sulphur and calcium depositions were somewhat higher in the open area than in earlier years (2004-2008). The soil solution quality in 2010 was also quite comparable to that in earlier years. The NH 4 -N and NO 3 -N concentrations were low at all depths in the mineral soil of the FIP plots 4, 10 and 11. Instead, nitrate concentrations were high in the soil solution on FIP14. There appeared to be a clear overall increase in sulphate concentrations with increasing depth on FIP4 and FIP10. Chloride concentrations in the soil solution were extremely high at all depths on all FIP plots throughout the monitoring period; it is clear that there is a considerable input of NaCl in the deposition derived from the sea. The concentrations of heavy metals (Cd, Cr, Ni, Pb) in the soil solution at all depths at Olkiluoto during 2004-2010 continued in many cases to be close to or below the limit of quantification. In 2010 the monthly level of transpiration in the Scots pine dominated stand was smaller in May and bigger in July than during previous years (2007-2009). Monthly transpiration in the Norway spruce dominated stand was clearly lower in 2010 than in 2007-2009, and there is a decreasing

Results of forest monitoring on Olkiluoto island in 2010

Energy Technology Data Exchange (ETDEWEB)

Aro, L.; Huhta, A.-P.; Hoekkae, H.; Lindroos, A.-J.; Rautio, P. [Finnish Forest Research Institute, Vantaa (Finland); Helmisaari, H.-S. [Helsinki Univ. (Finland)

2011-11-15

Forest investigations carried out on Olkiluoto aim to monitor the state of the forest ecosystems, quantify Olkiluoto-specific processes taking place in the forests producing input data for the safety assessment of spent nuclear fuel disposal, and follow possible changes in the forest condition resulting from the intensive construction activities currently being carried out in the area. The forest investigations form a part of the monitoring programme being carried out on Olkiluoto Island under the management of Posiva Oy. This report focuses on activities performed on bulk deposition and forest intensive monitoring plots (MRK and FIP plots) in 2010. In general, the deposition levels in 2010 in the open area and in stand throughfall were quite comparable to those in earlier years, although sulphur and calcium depositions were somewhat higher in the open area than in earlier years (2004-2008). The soil solution quality in 2010 was also quite comparable to that in earlier years. The NH{sub 4}-N and NO{sub 3}-N concentrations were low at all depths in the mineral soil of the FIP plots 4, 10 and 11. Instead, nitrate concentrations were high in the soil solution on FIP14. There appeared to be a clear overall increase in sulphate concentrations with increasing depth on FIP4 and FIP10. Chloride concentrations in the soil solution were extremely high at all depths on all FIP plots throughout the monitoring period; it is clear that there is a considerable input of NaCl in the deposition derived from the sea. The concentrations of heavy metals (Cd, Cr, Ni, Pb) in the soil solution at all depths at Olkiluoto during 2004-2010 continued in many cases to be close to or below the limit of quantification. In 2010 the monthly level of transpiration in the Scots pine dominated stand was smaller in May and bigger in July than during previous years (2007-2009). Monthly transpiration in the Norway spruce dominated stand was clearly lower in 2010 than in 2007-2009, and there is a

GPS Operations at Olkiluoto, Kivetty and Romuvaara in 2005

International Nuclear Information System (INIS)

Ahola, J.; Ollikainen, M.; Koivula, H.; Jokela, J.

2006-07-01

The GPS based deformation studies has been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. The network of seven GPS pillars was built at Kivetty and Romuvaara during the year 1996. One pillar in each investigation area belongs to the Finnish permanent GPS network, FinnRef. Twenty GPS measurement campaigns have been carried out at Olkiluoto since 1995, and fourteen campaigns at Kivetty and Romuvaara. According to the time series of the GPS results 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than ± 0.22 mm/a. There are no statistically signicant movements at Kivetty and Romuvaara expect one pillar at Romuvaara. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. The local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliable (maximum velocity is - 0.25 mm/a ± 0.025 mm/a). The uniform scale for the GPS measurements made in different years is the basic condition for reliable results in the deformation analyses. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured using EDM instruments simultaneously with the GPS observations. The comparison between the GPS and EDM results to show a possible scale error of the GPS. The GPS network at Olkiluoto was enlarged in 2003. The new pillars were built close to Kuivalahti village and on a small island of Iso Pyrekari, both north from Olkiluoto. According to the geological evidence it is expected that a fracture zone is located between the new stations, thus enabling the determination of possible deformations along the fracture zone. The new pillars have been observed five times since 2003, but the time series are still too short for reliable deformation studies. Including the new pillars the local

Sampling and characterisation of groundwater colloids at ONKALO, Olkiluoto, Finland

International Nuclear Information System (INIS)

Takala, M.; Manninen, P.

2006-11-01

The purpose of this sampling campaign was to test different filtering methods and filter membranes, to determine the colloid concentration and to characterise the composition of the colloid phase at ONKALO groundwater station ONK-PVA1 at Olkiluoto. The sampling was done on 18 to 19 April 2006. The filtering methods tested were downhole in-situ filtration and in-line syringe filtration. The membranes tested were Anopore 0.2-μm membrane and Nuclepore 0.05 -μm membrane. The Anopore filter was designed to be 0.02 -μm, but according to the SEM micrograph the nominal pore size of the membranes was 0.2 -μm. The size distributions were determined by single particle analysis of the SEM micrographs taken from the used filter membranes. The size distribution can be expressed as a function of the Pareto power law (Buffle, 1988). Parameters A and b of the Pareto power law distribution were determined by using the least square sum method. The particle and mass concentrations were then calculated using the Pareto power law. The size distribution varied between the filtering methods, so that the syringe filtered samples indicated less aggregation than the downhole filtered samples. The colloid concentrations were higher in the Nuclepore filter membranes. This is probably due to the shorter settling time prior to the sampling or differences in the membrane pore size and material. The concentration of the colloid phase determined from the anopore membranes (0.05-1 -μm) was 0.2-0.4 mg/L. The water samples were analysed at the accredited laboratory of Consulting Engineers Paavo Ristola Ltd. The differences in the element concentrations were not detectable between the filtered and unfiltered samples. Contamination with, e.g., nickel, aluminium and organic carbon was evident. The valves, fittings and filter membranes probably caused the contamination. An EDS spectrum was taken from the downhole filtered Nuclepore membrane. The filter cake showed traces of aluminium, silicon and

GPS operations at Olkiluoto, Kivetty and Romuvaara in 2008

International Nuclear Information System (INIS)

Kallio, U.; Ahola, J.; Koivula, H.; Jokela, J.; Poutanen, M.

2009-09-01

The GPS based deformation studies have been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. The network of seven GPS pillars was built at Kivetty and Romuvaara during the year 1996. One pillar in each investigation area belongs to the Finnish permanent GPS network, FinnRef. A total of 26 GPS measurement campaigns have been carried out at Olkiluoto since 1995, and 17 campaigns at Kivetty and Romuvaara. According to the time series of the GPS results 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than 0.20 mm/a. The networks of Kivetty and Romuvaara are quite stable expect one pillar at Romuvaara. There are seven pillars, which have statistically significant horizontal velocities at Olkiluoto. These local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliably determined. The uniform scale for the GPS measurements made in different years is the basic condition for reliable results in the deformation analyses. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured using EDM instruments in connection to the GPS observations. The comparison between the GPS and EDM results can help to fix a possible scale error of the GPS measurements. The GPS network at Olkiluoto was extended in 2003. The new pillars were built close to Kuivalahti village and on a small island of Iso Pyrekari. According to the geological evidence it is expected that a fracture zone is located between the new stations, thus enabling the determination of possible deformations along the fracture zone. The new pillars have been observed since 2003 and now we have computed the first deformation analysis from the six years data. The local crustal deformations have been studied in GeoSatakunta project, too. This GPS network is

GPS operations at Olkiluoto, Kivetty and Romuvaara in 2006

International Nuclear Information System (INIS)

Ahola, J.; Koivula, H.; Poutanen, M.; Jokela, J.

2007-05-01

The GPS based deformation studies have been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. The network of seven GPS pillars was built at Kivetty and Romuvaara during the year 1996. One pillar in each investigation area belongs to the Finnish permanent GPS network, FinnRef. 22 GPS measurement campaigns have been carried out at Olkiluoto since 1995, and 15 campaigns at Kivetty and Romuvaara. According to the time series of the GPS results 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than ± 0.22 mm/a. The networks of Kivetty and Romuvaara are quite stabile expect one pillar at Romuvaara. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. These local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliably determined (maximum velocity is -0.23 mm/a ± 0.023 mm/a). The uniform scale for the GPS measurements made in different years is the basic condition for reliable results in the deformation analyses. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured using EDM instruments simultaneously with the GPS observations. The comparison between the GPS and EDM results can solve a possible scale error of the GPS. The GPS network at Olkiluoto was extended in 2003. The new pillars were built close to Kuivalahti village and on a small island of Iso Pyrekari. According to the geological evidence it is expected that a fracture zone is located between the new stations, thus enabling the determination of possible deformations along the fracture zone. The new pillars have been observed since 2003, but the time series are still too short for reliable deformation studies. The local crustal deformations have been studied in GeoSatakunta project, too. This

GPS operations at Olkiluoto, Kivetty and Romuvaara in 2007

International Nuclear Information System (INIS)

Ahola, J.; Koivula, H.; Jokela, J.

2008-05-01

The GPS based deformation studies have been made at the investigation areas of Posiva since 1995, when the network of ten GPS pillars was established at Olkiluoto. The network of seven GPS pillars was built at Kivetty and Romuvaara during the year 1996. One pillar in each investigation area belongs to the Finnish permanent GPS network, FinnRef. 24 GPS measurement campaigns have been carried out at Olkiluoto since 1995, and 16 campaigns at Kivetty and Romuvaara. According to the time series of the GPS results 1/3 of the baselines at Olkiluoto have statistically significant change rates. However, the observed movements are smaller than ± 0.20 mm/a. The networks of Kivetty and Romuvaara are quite stabile expect one pillar at Romuvaara. There are five pillars, which have statistically significant horizontal velocities at Olkiluoto. These local velocity components are small but taking into account the standard deviations the largest velocity components seems to be reliably determined (maximum velocity is -0.22 mm/a ± 0.02 mm/a). The uniform scale for the GPS measurements made in different years is the basic condition for reliable results in the deformation analyses. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured using EDM instruments simultaneously with the GPS observations. The comparison between the GPS and EDM results can solve a possible scale error of the GPS. The GPS network at Olkiluoto was extended in 2003. The new pillars were built close to Kuivalahti village and on a small island of Iso Pyrekari. According to the geological evidence it is expected that a fracture zone is located between the new stations, thus enabling the determination of possible deformations along the fracture zone. The new pillars have been observed since 2003, but the time series are still too short for reliable deformation studies. The local crustal deformations have been studied in GeoSatakunta project, too. This

Completed lineament interpretation of the Olkiluoto region

International Nuclear Information System (INIS)

Paananen, M.

2013-10-01

dominating. The EM lineaments are mainly related to electrically conductive narrow sea areas between the islands. Accordingly, they may be indirect indications of deformation zones. In addition to the sole geophysical interpretation, the result is also merged with the revision of the most recent previous lineament interpretation, based on several data sources, such as geophysics, topography and bathymetry. The compiled interpretation, resulting in altogether 200 lineaments, serves as one starting point when constructing the geological model of the Olkiluoto site. (orig.)

Completed lineament interpretation of the Olkiluoto region

Energy Technology Data Exchange (ETDEWEB)

Paananen, M. [Geological Survey of Finland, Espoo (Finland)

2013-10-15

dominating. The EM lineaments are mainly related to electrically conductive narrow sea areas between the islands. Accordingly, they may be indirect indications of deformation zones. In addition to the sole geophysical interpretation, the result is also merged with the revision of the most recent previous lineament interpretation, based on several data sources, such as geophysics, topography and bathymetry. The compiled interpretation, resulting in altogether 200 lineaments, serves as one starting point when constructing the geological model of the Olkiluoto site. (orig.)

Results of monitoring at Olkiluoto in 2009. Environment

Energy Technology Data Exchange (ETDEWEB)

Haapanen, A. (ed.) (Haapanen Forest Consulting, Vanhakylae (Finland))

2010-10-15

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2009. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to the experiences gained from the modelling work and an increased understanding of the site. Augmentations in 2009 include e.g. establishment of a new forest intensive monitoring plot (FIP14), continuation of studies on fine roots and on the species composition and abundances of small mammals. Line transect samplings of ants, terrestrial snails and earthworms were carried out and a systematic monitoring of island birds was started. In addition, a project was started where the sediment load and factors affecting the sediment transportation into Eurajoensalmi bay is examined. Dust produced during construction of the third nuclear power unit (OL3), ONKALO and related infrastructure can be seen in the soil solution and deposition results. Furthermore, the construction works and road traffic have a raising effect on the noise levels of the immediate surroundings. The land-use continues to change, but the remaining natural environment resembles other coastal locations. The young age of the soils and the closeness of the sea are reflected in the soil properties. Mammalian fauna on the island is typical of coastal

Results of monitoring at Olkiluoto in 2009. Environment

International Nuclear Information System (INIS)

Haapanen, A.

2010-10-01

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2009. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to the experiences gained from the modelling work and an increased understanding of the site. Augmentations in 2009 include e.g. establishment of a new forest intensive monitoring plot (FIP14), continuation of studies on fine roots and on the species composition and abundances of small mammals. Line transect samplings of ants, terrestrial snails and earthworms were carried out and a systematic monitoring of island birds was started. In addition, a project was started where the sediment load and factors affecting the sediment transportation into Eurajoensalmi bay is examined. Dust produced during construction of the third nuclear power unit (OL3), ONKALO and related infrastructure can be seen in the soil solution and deposition results. Furthermore, the construction works and road traffic have a raising effect on the noise levels of the immediate surroundings. The land-use continues to change, but the remaining natural environment resembles other coastal locations. The young age of the soils and the closeness of the sea are reflected in the soil properties. Mammalian fauna on the island is typical of coastal

Eurajoki Olkiluoto birdlife survey 2008

International Nuclear Information System (INIS)

Yrjoelae, R.

2009-02-01

The study of birds in Olkiluoto in the summer of 2008 repeated the study of the same area conducted in 1997 (Yrjoelae 1997), and was complemented with two new line transect routes and six new waterfowl counting points for the eastern region of the Olkiluoto island. Using this method the research project covered the whole area of the Olkiluoto island. By repeating the earlier routes and counting points it presented an opportunity to clarify any possible changes in the area. A wide variety of different biotypes are evident in the mixed-growth forests of the whole Olkiluoto island and after that are both spruce and pine forests. There are regionally, however, great differences in the division. In the western sector of the island, on the first three lines, the share of industrial areas and the road network are noticeable. The methods used were line transects for the bird species found on the ground and point checks for the aquatic species of birds (Koskimies and Vaeisaenen 1998), which are the established methods used for the monitoring of birdlife in Finland. In these calculations, the bird observations were 1429 altogether, covering 65 species. The results of the checkpoint census for waterfowl are presented in this study. Altogether, 23 species were interpreted in the census for waterfowl as pairs appearing to nest in the area of the checkpoints. The endangered, or other species mentioned in the EU bird directive, sighted in Olkiluoto in summer 2008 are listed in this study. The Redbacked Shrike and Common Chiffchaff were clearly the most common among these species. The birdlife in Olkiluoto is both rather varied and abundant. A few clear tendencies can be distinguished in the changes within the species of birds. Amongst the waterfowl and gulls, the species favouring flourishing watercourses have increased. The species in the outer archipelago, such as the Common Eider and Velvet Scoter have declined compared to 1997. Probably the waders of the archipelago will

Characterization of Olkiluoto bacterial and archaeal communities by 454 pyrosequencing

Energy Technology Data Exchange (ETDEWEB)

Bomberg, M.; Nyyssoenen, M.; Itaevaara, M. [VTT Technical Research Centre of Finland, Espoo (Finland)

2012-06-15

Recent advancement in sequencing technologies, 'Next Generation Sequencing', such as FLX 454 pyrosequencing has made it possible to obtain large amounts of sequence data where previously only few sequences could be obtained. This technique is especially useful for the study of community composition of uncultured microbial populations in environmental samples. In this project, the FLX 454 pyrosequencing technique was used to obtain up to 20 000 16S rRNA sequences or 10 000 mRNA sequences from each sample for identification of the microbial species composition as well as for comparison of the microbial communities between different samples. This project focused on the characterization of active microbial communities in the groundwater at the final disposal site of high radioactive wastes in Olkiluoto by FLX 454 pyrosequencing of the bacterial and archaeal ribosomal RNA as well as of the mRNA transcripts of the dsrB gene and mcrA gene of sulphate reducing bacteria and methanogenic archaea, respectively. Specific emphasis was put on studying the relationship of active and latent sulphate reducers and methanogens by qPCR due to their important roles in deep geobiochemical processes connected to copper corrosion. Seven packered boreholes were sampled anaerobically in Olkiluoto during 2009-2010. Groundwater was pumped from specific depths and the microbial cells werecollected by filtration on a membrane. Active microbial communities were studied based on RNA extracted from the membranes and translated to copy DNA, followed by sequencing by 454 Tag pyrosequencing. A total of 27 different bacterial and 17 archaeal taxonomic groups were detected.

Characterization of Olkiluoto bacterial and archaeal communities by 454 pyrosequencing

Energy Technology Data Exchange (ETDEWEB)

Bomberg, M; Nyyssoenen, M; Itaevaara, M [VTT Technical Research Centre of Finland, Espoo (Finland)

2012-06-15

Recent advancement in sequencing technologies, 'Next Generation Sequencing', such as FLX 454 pyrosequencing has made it possible to obtain large amounts of sequence data where previously only few sequences could be obtained. This technique is especially useful for the study of community composition of uncultured microbial populations in environmental samples. In this project, the FLX 454 pyrosequencing technique was used to obtain up to 20 000 16S rRNA sequences or 10 000 mRNA sequences from each sample for identification of the microbial species composition as well as for comparison of the microbial communities between different samples. This project focused on the characterization of active microbial communities in the groundwater at the final disposal site of high radioactive wastes in Olkiluoto by FLX 454 pyrosequencing of the bacterial and archaeal ribosomal RNA as well as of the mRNA transcripts of the dsrB gene and mcrA gene of sulphate reducing bacteria and methanogenic archaea, respectively. Specific emphasis was put on studying the relationship of active and latent sulphate reducers and methanogens by qPCR due to their important roles in deep geobiochemical processes connected to copper corrosion. Seven packered boreholes were sampled anaerobically in Olkiluoto during 2009-2010. Groundwater was pumped from specific depths and the microbial cells werecollected by filtration on a membrane. Active microbial communities were studied based on RNA extracted from the membranes and translated to copy DNA, followed by sequencing by 454 Tag pyrosequencing. A total of 27 different bacterial and 17 archaeal taxonomic groups were detected.

Characterization of Olkiluoto bacterial and archaeal communities by 454 pyrosequencing

International Nuclear Information System (INIS)

Bomberg, M.; Nyyssoenen, M.; Itaevaara, M.

2012-06-01

Recent advancement in sequencing technologies, 'Next Generation Sequencing', such as FLX 454 pyrosequencing has made it possible to obtain large amounts of sequence data where previously only few sequences could be obtained. This technique is especially useful for the study of community composition of uncultured microbial populations in environmental samples. In this project, the FLX 454 pyrosequencing technique was used to obtain up to 20 000 16S rRNA sequences or 10 000 mRNA sequences from each sample for identification of the microbial species composition as well as for comparison of the microbial communities between different samples. This project focused on the characterization of active microbial communities in the groundwater at the final disposal site of high radioactive wastes in Olkiluoto by FLX 454 pyrosequencing of the bacterial and archaeal ribosomal RNA as well as of the mRNA transcripts of the dsrB gene and mcrA gene of sulphate reducing bacteria and methanogenic archaea, respectively. Specific emphasis was put on studying the relationship of active and latent sulphate reducers and methanogens by qPCR due to their important roles in deep geobiochemical processes connected to copper corrosion. Seven packered boreholes were sampled anaerobically in Olkiluoto during 2009-2010. Groundwater was pumped from specific depths and the microbial cells werecollected by filtration on a membrane. Active microbial communities were studied based on RNA extracted from the membranes and translated to copy DNA, followed by sequencing by 454 Tag pyrosequencing. A total of 27 different bacterial and 17 archaeal taxonomic groups were detected

GPS operations at Olkiluoto in 2011

International Nuclear Information System (INIS)

Koivula, H.; Kallio, U.; Nyberg, S.; Jokela, J.; Poutanen, M.

2012-06-01

The Finnish Geodetic Institute has studied crustal deformations at Olkiluoto, Kivetty and Romuvaara in co-operation with Posiva Oy since 1995. At Olkiluoto a total of 32 GPS campaigns have been carried out at inner network since 1995 and 17 campaigns at outer network since 2003. Kivetty and Romuvaara were not measured in 2011. In the Olkiluoto inner network 80 percent of the estimated change rates are smaller than 0.10 mm/a. One third of the change rates are statistically significant. They are mainly related to the Olkiluoto permanent station (GPS1) and to the pillars GPS6 and GPS13. The change rates related to GPS6 are not realistic due to the site-specific changes affecting the time series. The maximum change rate (-0.20 mm/a ± 0.05 mm/a) is related to GPS13. The time series of GPS13 is half the length of other pillars and therefore, the change rates are more uncertain. In the Olkiluoto outer network the maximum and statistically significant change rate is between GPS1-GPS11 (0.39 mm/a ± 0.06 mm/a). Pillar GPS12 was not observed this year. The change rates of baselines GPS1-GPS14 and GPS1-GPS15 are first time statistically significant. The change rates indicate a small movement of the GPS1 pillar. The baseline GPS1-GPS11 crosses an old fracture zone locating in the direction of the Eurajoensalmi, which might be a reason for the deformation. On the other hand, the Onkalo excavations in the vicinity of the Olkiluoto permanent station (GPS1) may cause some movement. Electronic distance measurements have been performed at Olkiluoto at the baseline GPS7-GPS8 using the Mekometer since 2002. The measurements have been carried out simultaneously with GPS campaigns. Based on 19 measurements in 10 years, the trends of the two time series seems to be similar. Due to unmodelled or dismodelled geometrical offsets and the scale difference between GPS measurements and EDM there is about 0.3 mm difference between distances GPS7-GPS8 derived from GPS measurements and EDM. It is

GPS operations at Olkiluoto in 2011

Energy Technology Data Exchange (ETDEWEB)

Koivula, H.; Kallio, U.; Nyberg, S.; Jokela, J.; Poutanen, M. [Finnish Geodetic Institute, Masala (Finland)

2012-06-15

The Finnish Geodetic Institute has studied crustal deformations at Olkiluoto, Kivetty and Romuvaara in co-operation with Posiva Oy since 1995. At Olkiluoto a total of 32 GPS campaigns have been carried out at inner network since 1995 and 17 campaigns at outer network since 2003. Kivetty and Romuvaara were not measured in 2011. In the Olkiluoto inner network 80 percent of the estimated change rates are smaller than 0.10 mm/a. One third of the change rates are statistically significant. They are mainly related to the Olkiluoto permanent station (GPS1) and to the pillars GPS6 and GPS13. The change rates related to GPS6 are not realistic due to the site-specific changes affecting the time series. The maximum change rate (-0.20 mm/a {+-} 0.05 mm/a) is related to GPS13. The time series of GPS13 is half the length of other pillars and therefore, the change rates are more uncertain. In the Olkiluoto outer network the maximum and statistically significant change rate is between GPS1-GPS11 (0.39 mm/a {+-} 0.06 mm/a). Pillar GPS12 was not observed this year. The change rates of baselines GPS1-GPS14 and GPS1-GPS15 are first time statistically significant. The change rates indicate a small movement of the GPS1 pillar. The baseline GPS1-GPS11 crosses an old fracture zone locating in the direction of the Eurajoensalmi, which might be a reason for the deformation. On the other hand, the Onkalo excavations in the vicinity of the Olkiluoto permanent station (GPS1) may cause some movement. Electronic distance measurements have been performed at Olkiluoto at the baseline GPS7-GPS8 using the Mekometer since 2002. The measurements have been carried out simultaneously with GPS campaigns. Based on 19 measurements in 10 years, the trends of the two time series seems to be similar. Due to unmodelled or dismodelled geometrical offsets and the scale difference between GPS measurements and EDM there is about 0.3 mm difference between distances GPS7-GPS8 derived from GPS measurements and EDM

Paleohydrogeological implications from fracture calcites and sulfides in a major hydrogeological zone HZ19 at Olkiluoto

International Nuclear Information System (INIS)

Sahlstedt, E.; Karhu, J.; Rinne, K.

2009-08-01

30 samples of fracture mineral fillings in or near water conducting fractures at Olkiluoto were collected from 10 drill cores for fracture mineral studies. The aim of the study was to obtain information about past hydrogeochemical conditions at Olkiluoto using the calcite morphology, the chemical characteristics and the isotopic composition of carbon and oxygen in calcite. The chemical composition of fracture calcites at Olkiluoto is nearly stoichiometric CaCO 3 . Most variation in the composition of calcite is due to differences in the Mn content, which could indicate variations in groundwater redox conditions. Meaningful REE patterns were obtained for the calcites. REE patterns showed generally negative Eu anomalies, but one fracture calcite specimen had a distinct positive Eu anomaly. This positive anomaly could be related to ancient hydrothermal conditions, although derivation of the anomaly from the host rock cannot be excluded. Preliminary results for calcite U-Th dating of fracture calcites are reported. The isotopic composition of U and Th were analysed by a new multiple collector LA-ICPMS instrument. U and Th concentrations in fracture calcites are generally 18 O values of calcite range from -17 to -7 per mille. Most of the calcites may have been precipitated in the presence of waters with oxygen isotope ratios similar to those in the present-day groundwaters at Olkiluoto. Two samples with an oxygen isotopic composition highly depleted in 18 O were interpreted to have been precipitated at elevated temperatures. The δ 13 C values of calcite showed a wide range of values from -26 to +35 per mille. Multiple sources for carbon are implied. The highest δ 13 C values indicate methanic conditions in the fracture at the time of calcite precipitation. It appears that the methanic environment has earlier extended to shallower depths compared to the location of the methanic environment in the present-day fracture system (> 300 m). Ten pyrite samples were analysed

Evaluation and modelling of a potential repository site - Olkiluoto case study

International Nuclear Information System (INIS)

Saksa, P.; Ahokas, H.; Loefman, J.; Pitkaenen, P.; Paulamaeki, S.; Snellman, M.

1998-01-01

The observations, interpretations and estimates resulting from site investigations were developed into conceptual bedrock model of the Olkiluoto area. Model development has been an interdisciplinary process and three major iterations have occurred. Geochemical sampling and a programme of electromagnetic and electrical soundings were carried out and interpreted to model occurrences of groundwater types. The parametrisation and modifications needed between geological models and ground-water flow simulation model is discussed. The latest groundwater flow modelling effort comprises the transient flow analysis taking into account the effects of density variations, the repository, post-glacial land uplift and global sea level rise. The main flow modeling result quantities (the amount, direction, velocity and routes as well as concentration of water) are used for evaluation of the investigation sites and of the preconditions for safe final disposal of spent nuclear fuel. Integration of hydrological and hydrogeochemical methods and studies has provided the primary method for investigating the evolution. Testing of flow models with hydro-geochemical information is considered to improve the hydrogeological understanding of a site and increases confidence in conceptual hydrogeological models. Bedrock model allows also comparisons to be made between its time-varying versions. The evolution of fracture frequency, fracture zone structures and hydraulic conductivity has been studied. A prediction-outcome comparison was made in selected boreholes and showed that the rock type was the easiest parameter to predict

Results of Monitoring at Olkiluoto in 2009. Hydrogeochemistry

International Nuclear Information System (INIS)

Penttinen, T.; Lahdenperae, A.-M.; Ahokas, T.; Partamies, S.; Kasa, S.; Pitkaenen, P.

2011-01-01

The construction work of underground research facility ONKALO started in the autumn 2004. Possible changes caused by the construction of the disposal facility in the chemical environment in shallow and deep groundwaters are monitored on a regular basis. This report presents the hydrogeochemical monitoring measurements and observations made in 2009. A total of 31 shallow groundwater samples were taken in monitoring programme and 49 shallow groundwater samples in the Infiltration experiment area in 2009. The sampling points of shallow groundwaters were divided into groups on a basis of their typical geological and geographic features. The seasonal variation in concentration levels was now clearly observed in OL-PVP3A, OL-PVP13, OL-PVP14, OL-PVP17, OL-PVP18A, OL-PVP20, OL-PP39 and OL-PP56. This behaviour is related to high naturally fluctuating concentrations in these sampling sites. The effect of Korvensuo on the groundwater of OL-PVP30 appeared. No straight connection can be made with the ONKALO construction work and the observed changes in shallow groundwater concentrations. 47 deep groundwater samplings were carried out during the year 2009 from 19 different drillholes and 30 groundwater samples were taken from ONKALO. 10 gas samples have been analysed and collected from 6 open drillholes during the year 2009 and 5 are from sampling points of ONKALO. The results from ground surface based monitoring campaign in 2009 show indications of changes in groundwater compositions, which are most probably caused by high hydraulic gradient of ONKALO. The 2009 results show slight but clear systematic dilution (in all species) in two monitoring points (OL-KR4 T 76 and OL-KR37 T 165, both intersections of HZ19) relative to the previous samplings. Of the monitored intersections of hydraulic zone HZ20B the OL-KR10 T 326 have continued dilution trend (after packering) and OL-KR9 T 468 and OL-KR23 T 424 h ave become more saline. Particularly the start of salinity increase in OL-KR9

Results of sampling and analysis of groundwater from multi-packered boreholes OL-KR1, OL-KR3, OL-KR5, OL-KR9, OL-KR11 and OL-KR12 at Olkiluoto, Eurajoki, in 2004

Energy Technology Data Exchange (ETDEWEB)

Hirvonen, H. [Teollisuuden Voima Oyj, Eurajoki (Finland); Hatanpaeae, E. [lnsinoeoeritoimisto Paavo Ristola Oy, Hollola (Finland)

2005-12-15

Nine groundwater samples were collected at Olkiluoto from deep multi-packered boreholes OL-KR1, OL-KR3, OL-KR5, OL-KR9, OL-KR11 and OL-KR12 between spring 2004 and the beginning of 2005. The aim of the ground water sampling was to get information for the basis of the monitoring program (OMO) during ONKALO construction. Sampling sections were mainly chosen so that the results of the chemical analyses from earlier studies could be used for comparison. This study presents the sampling methods and the results of the laboratory analyses of groundwater samples from the deep multi-packered boreholes OL-KR1 (151.2-156.8 m, 311.2-336.8 m and 524.4-528.4 m), OL-KR3 (242.6-253.2 m), OL-KR5 (277.2-284.6 m and 457.2-476.2 m), OL-KR9 (468.2-482.2 m), OL-KR11 (597.5-628.1 m) and OLKR12 (363-368 m). The analytical results of the groundwater samplings are compared to earlier analytical results. According to Davis and De Wiest's (1967) classification, the collected groundwater samples represent either the borehole water type Na-Cl (OL-KR1/T/151.2-156.8 m, OLK-R1/ T/311.2-336.8 m, OL-KR3/T/242.6-253.2 m, OL-KR5/T/277.2-284.6 m, OL-KR11/ T/597.5-628.1 m and OL-KR12/T/363-368 m) or Na-Ca-Cl (OL-KR1/T/524.4- 528.4 m, OL-KR5/T/457.2-476.2 m and OL-KR9/T/468.2-482.2 m). The groundwater samples from OL-KR1/T/151.2-156.8 m, OL-KR3/T/242.6- 253.2 m, OL-KR3/T/242.6-253.2 m, OL-KR5/T/277.2-284.2 m, OL-KR11/T/597.5-628.1 m and OL-KR12/T/363-368 m were brackish (1000 mg/L < TDS < 10000 mg/L) according to Davis's (1964) TDS classification. Other samples (OL-KR1/T/524.4-528.4 m, OL-KR5/ T/457.2-476.2 m and OL-KR9/T/468.2-482.2 m), were saline (TDS> 10000 mg/L). Comparison of analytical results of the samples to earlier results shows that some changes were seen between samplings done at the different times. Only the groundwater sampled from OL-KR1/T/311.2-336.8 m had significant changes in its chemical composition during the reference period, but also in OL-KR1/T/524.4-528.4 m, OL-KR5/ T

Installation of groundwater observation tubes OL-PVP39 - 40 and drilling of shallow drillhole OL-PP90 at Olkiluoto in Eurajoki 2013

Energy Technology Data Exchange (ETDEWEB)

Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

2013-11-15

In order to extend the groundwater monitoring network at Olkiluoto, Posiva Oy contracted Suomen Malmi Oy (Smoy) to install new groundwater observation tubes to two locations and to drill one shallow drillhole with a standpipe. The identification numbers of the groundwater observation tubes are OL-PVP39, OL-PVP40A and 40B, and the shallow drillhole is named OL-PP90. The observation tubes were installed and the shallow hole drilled between July 29th and August 6th in 2013. The drilling rig used in the installation work was a GM-200 rig. Drilling equipment consisted of casing tubes (v 90/77 mm) with drilling bit, 55 mm geo rods and 64 mm drilling bits and T76-equipment for drilling the shallow hole. Monitoring pipes (PVC, v 60/52 mm) were lowered into the holes inside the casings. The monitoring pipes consist of a lower section of riser pipe, a middle section of screen pipe and an upper section of riser pipe. The screen pipe slot size is 0.3 mm and the length of the screen section is two or three metres. Protective stainless steel covers with lock-up caps were installed around the monitoring tubes and the shallow drillholes. In addition to the installation of the tubes, the work included water level measurements after installation. The core samples of the shallow drillhole were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. (orig.)

GPS operations at Olkiluoto, Kivetty and Romuvaara in 2010

International Nuclear Information System (INIS)

Kallio, U.; Nyberg, S.; Koivula, H.; Jokela, J.; Poutanen, M.

2011-11-01

The Finnish Geodetic Institute (FGI) has studied crustal deformations in co-operation with the Posiva Oy since 1994, when a network of ten pillars for GPS observations was established at Olkiluoto. In 2010 the local GPS network at Olkiluoto consisted of 14 concrete pillars. The whole network has been measured twice a year in the static GPS campaigns with 24 h sessions. The four new pillars were established in 2010 and the permanent measurements on them will start in 2011. The network of seven GPS pillars was built at Kivetty and Romuvaara during the year 1996. One pillar in each investigation area belongs to the Finnish permanent GPS network, FinnRef. A total of 28 GPS measurement campaigns have been carried out at Olkiluoto since 1995, and 18 campaigns at Kivetty and Romuvaara. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured in connection to the GPS observations using the EDM instrument Kern ME5000 Mekometer. The GPS operations in 2010 included the two GPS campaigns at Olkiluoto, GPS campaigns at Kivetty and Romuvaara, EDM baseline measurements at Olkiluoto, and the control marker measurements with the tachymeter at Olkiluoto. All GPS data history was reprocessed with Bernese GPS software using the new processing strategy tested in 2009. The results were analysed by computing the change rates of the baselines and estimating horizontal velocities for the pillars using the barycenter of the velocities as a reference. In the Olkiluoto inner network 80 percent of the change rates were smaller than 0.10 mm/a. Roughly one fourth of the change rates could be considered as statistically significant (change rate larger than 3 σ. The statistically significant change rates were mainly related to the Olkiluoto permanent station (GPS1) and to the pillar GPS5, which had also the maximum change rate (0.21 ± 0.03 mm/a). In Olkiluoto outer network the maximum and statistically significant change rates are

GPS operations at Olkiluoto, Kivetty and Romuvaara in 2010

Energy Technology Data Exchange (ETDEWEB)

Kallio, U.; Nyberg, S.; Koivula, H.; Jokela, J.; Poutanen, M. [Finnish Geodetic Institute, Masala (Finland)

2011-11-15

The Finnish Geodetic Institute (FGI) has studied crustal deformations in co-operation with the Posiva Oy since 1994, when a network of ten pillars for GPS observations was established at Olkiluoto. In 2010 the local GPS network at Olkiluoto consisted of 14 concrete pillars. The whole network has been measured twice a year in the static GPS campaigns with 24 h sessions. The four new pillars were established in 2010 and the permanent measurements on them will start in 2011. The network of seven GPS pillars was built at Kivetty and Romuvaara during the year 1996. One pillar in each investigation area belongs to the Finnish permanent GPS network, FinnRef. A total of 28 GPS measurement campaigns have been carried out at Olkiluoto since 1995, and 18 campaigns at Kivetty and Romuvaara. At Olkiluoto a baseline for electronic distance measurements (EDM) was built in 2002. The baseline has been measured in connection to the GPS observations using the EDM instrument Kern ME5000 Mekometer. The GPS operations in 2010 included the two GPS campaigns at Olkiluoto, GPS campaigns at Kivetty and Romuvaara, EDM baseline measurements at Olkiluoto, and the control marker measurements with the tachymeter at Olkiluoto. All GPS data history was reprocessed with Bernese GPS software using the new processing strategy tested in 2009. The results were analysed by computing the change rates of the baselines and estimating horizontal velocities for the pillars using the barycenter of the velocities as a reference. In the Olkiluoto inner network 80 percent of the change rates were smaller than 0.10 mm/a. Roughly one fourth of the change rates could be considered as statistically significant (change rate larger than 3 {sigma}. The statistically significant change rates were mainly related to the Olkiluoto permanent station (GPS1) and to the pillar GPS5, which had also the maximum change rate (0.21 {+-} 0.03 mm/a). In Olkiluoto outer network the maximum and statistically significant change rates

Deformations during saturation of the crushed aggregate, Olkiluoto tonalite

International Nuclear Information System (INIS)

Laaksonen, R.; Rathmayer, H.; Takala, J.; Toernqvist, J.

1994-03-01

Crushed aggregate tonalite produced of crystalline tonalite or a correspondent rock with particle size up to 8 mm (or 16 mm) will be used as backfill material in the VLJ repository caverns at Olkiluoto (in Finland). The backfill material has to retard radionuclides, to restrict the groundwater perlocation and to support mechanically the concrete structure of the repository silos. Mechanical and hydraulic behaviour of crushed tonalite when effected by stresses applied during compaction of the backfill and due to groundwater perlocation was studied at three batches having different gradations. Information about the phenomenon of settlement due to saturation and as a function of the compaction methods was obtained from a literature survey. The maximum amount of possible deformation due to compaction was analyzed with a gyratory device, known to have a good repeatability. In a group of simulation tests using a large oedometer cell the amount of compression due to the saturation process was measured. Also studies on the suitability of different compaction methods could be done with these tests. (43 refs., 49 figs., 3 tabs.)

Core drilling of drillhole ONK-PVA8 in ONKALO at Olkiluoto 2010

International Nuclear Information System (INIS)

Toropainen, V.

2010-12-01

Suomen Malmi Oy (Smoy) core drilled a drillhole for groundwater monitoring station in ONKALO at Eurajoki, Olkiluoto in July 2010. The groundwater monitoring stations are used for monitoring changes in groundwater conditions. The identification number of the hole is ONK-PVA8, and the length of the drillhole is 17.74 m. The drillhole is 75.7 mm by diameter. The drillhole was drilled in a niche of the access tunnel at chainage 2935. The hydraulic DE 130 drilling rig was used. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. In addition to drilling the drillcores were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillholes are diatexitic gneiss and pegmatitic granite. The average fracture frequency in drill core ONK-PVA8 is 1.7 pcs / m and the average RQD value 96.0 %. (orig.)

Gefinex 400S (Sampo) EM-soundings at Olkiluoto 2008

International Nuclear Information System (INIS)

Jokinen, T.; Lehtimaeki, J.

2008-09-01

In the beginning of June 2008 Geological Survey of Finland (GTK) carried out electromagnetic frequency soundings with Gefinex 400S equipment (Sampo) in the vicinity of ONKALO at the Olkiluoto site investigation area. The same soundings sites were first time measured and marked in 2004 and has been repeated after it yearly in the same season. The aim of the measurements is to monitor the changes of groundwater conditions by the changes of the electric conductivity of the earth at ONKALO and repository area. The measurements form two 1400 m long broadside profiles, which have 200 m mutual distance and 200 m station separation. The profiles have been measured using 200, 500, and 800 m coil separations. Because of the strong electromagnetic noise all planned sites (48) could not be measured. In 2008 the measurements were performed at the sites that were successful in 2007 (43 soundings). The numerous power lines and cables in the area generate local disturbances on the sounding curves, but the signal/noise also with long coil separations and the repeatability of the results is reasonably good. However, most suitable for monitoring purposes are the sites without strong surficial 3D effects. Comparison of the results of 2004 to 2008 surveys shows differences on some ARD (Apparent resistivity-depth) curves. Those are mainly results of the modified man-made structures. The effects of changes in groundwater conditions are obviously slight. (orig.)

Results of Monitoring at Olkiluoto in 2004. Environment

International Nuclear Information System (INIS)

Haapanen, R.

2005-07-01

This report presents the main results of the environmental monitoring programme connected with Posiva Oy's activities on Olkiluoto island. This is the first annual report and covers the years 2004 and partly 2003. Monitoring has been carried out for varying time periods depending on the sector: some monitoring activities performed by TVO originate from the 1970s, others connected with the construction of the final disposal repository for nuclear waste and the underground research facility ONKALO are about to start. The system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for environmental impact analyses. No unexplainable deviations from reference data were seen in the results presented in this report. The vegetation, forests, soils and animal life are typical of a coastal region within the same vegetation zone. The nearby marine environment is affected by the cooling water from the nuclear power plant, to varying extents depending on the organism and the distance. Monitoring of marine environments as well as radionuclide analyses at the moment produce reference data for the future and create a basis for the construction of a model, as no input from Posiva's activities will influence these areas for a long time. (orig.)

Investigation plan for infiltration experiment in Olkiluoto

International Nuclear Information System (INIS)

Lehtinen, A.; Lindgren, S.; Ikonen, A.

2008-11-01

A three-year field experiment to investigate potential changes in pH and redox conditions, and in buffering capacity as well as the hydrogeochemical processes related to groundwater infiltration is designed for implementation in the vicinity of ONKALO. The idea is to monitor the major infiltration flow path from the ground surface into the upper part of ONKALO at about 50 to 100 m depth depending on the observations made during the experiment. The geochemical evolution of the groundwater is strongly affected by infiltration from the surface. In natural conditions in Olkiluoto most of the geochemical reactions occur along the first few tens of metres of the flow path, in an interface between anaerobic and aerobic conditions. The dissolved aggressive agents, CO 2 and O 2 , of the infiltrating water are consumed and the hydrogeochemistry stabilises on neutral and anaerobic conditions due to weathering processes. As a consequence of this evolution, reaction fronts are formed in the flow channels between acid-neutral and aerobic-anaerobic interfaces. The construction of ONKALO may, however, increase the hydraulic gradient and flow into bedrock, which can move these fronts to deeper depths and decrease the buffering capacity of the rock fractures against surficial water infiltration. Detailed integration of hydrogeochemical (including microbiology), geological and hydrogeological studies is essential for a successful experiment. Accurate hydrogeochemical and hydrogeological data that will be collected during this experiment are used in coupled modelling exercises (P/O studies in site reports), which will be carried out to evaluate the movements of the reaction fronts and the buffering capacity of Olkiluoto bedrock against surficial water infiltration. Good quality information is also necessary for calibrating predictive calculations for the safety case estimating future evolution of the site. In addition to the geochemical targets, the experiment can be used in

Chemical and physical properties of the surface sea sediments at the Olkiluoto offshore, South-Western Finland

International Nuclear Information System (INIS)

Lahdenperae, A.-M.; Keskinen, A.

2011-11-01

Due to land uplift, the present sea sediments near Olkiluoto will be future land areas, and thus important for the transport of possible releases from nuclear waste repositories at the site. Coastal areas are the transition zones between land and sea, and also potential sites for deep groundwater discharge. The geochemical properties of the surface sediments at the Olkiluoto sea area are summarised in this report. Thirteen sediment samples were cored during the R/V Geomari cruise in autumn 2008. In addition, surface sediment samples from six transects, altogether 57 cores, were taken near the Olkiluoto shoreline by diving in the summer of 2008. The analysis procedure included pH, moisture, dry matter, ash and LOI contents, grain size distribution, carbon and nitrogen analyses and the total concentrations of thirtythree elements. The lateral and vertical distribution of element concentrations, especially heavy metals, is caused by variations in transport and sedimentation patterns of particulate matter, in the occurrence of migration processes and bonding types. The distribution pattern in most of the elements is strongly linked to that of organic matter, carbon and fine-grained material contents. The sediments are strongly enriched by some of the studied elements possibly due to anthropogenic load, while others are only moderately or slightly present. However, the source of different natural and anthropogenic loads is not easy to point out. (orig.)

Installation of groundwater observation tubes OL-PVP36-38 and drilling of shallow drillholes OL-PP70-71 at Olkiluoto in Eurajoki 2011

International Nuclear Information System (INIS)

Toropainen, V.

2012-05-01

In order to widen the groundwater monitoring network at Olkiluoto, Posiva Oy contracted Suomen Malmi Oy (Smoy) to install new groundwater observation tubes to three locations and to drill two shallow drillholes with standpipes. The identification numbers of the groundwater observation tubes are OL-PVP36, OL-PVP37A, 37B, 37C, OL-PVP38A, 38B, 38C and 38D, and the shallow drillholes are named OL-PP70 and OL-PP71. The observation tubes were installed and the shallow holes drilled between September 22nd and October 12th in 2011. The drilling rig used in the installation work was a GM-200 rig. Drilling equipment consisted of casing tubes (90/77 mm) with drilling bit, 55 mm geo rods and 64 mm drilling bits and T76-equipment for drilling the shallow holes. Monitoring pipes (PVC, 60/52 mm) were lowered into the holes inside the casings. The monitoring pipes consist of a lower section of riser pipe, a middle section of screen pipe and an upper section of riser pipe. The screen pipe slot size is 0.3 mm and the length of the screen section is two metres. Protective stainless steel covers with lock-up caps were installed around the monitoring tubes and the shallow drillholes. In addition to the installation of the tubes, the work included water level measurements after installation. The core samples of the shallow drillholes were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. (orig.)

Installation of groundwater observation tubes OL-PVP36-38 and drilling of shallow drillholes OL-PP70-71 at Olkiluoto in Eurajoki 2011

Energy Technology Data Exchange (ETDEWEB)

Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

2012-05-15

In order to widen the groundwater monitoring network at Olkiluoto, Posiva Oy contracted Suomen Malmi Oy (Smoy) to install new groundwater observation tubes to three locations and to drill two shallow drillholes with standpipes. The identification numbers of the groundwater observation tubes are OL-PVP36, OL-PVP37A, 37B, 37C, OL-PVP38A, 38B, 38C and 38D, and the shallow drillholes are named OL-PP70 and OL-PP71. The observation tubes were installed and the shallow holes drilled between September 22nd and October 12th in 2011. The drilling rig used in the installation work was a GM-200 rig. Drilling equipment consisted of casing tubes (90/77 mm) with drilling bit, 55 mm geo rods and 64 mm drilling bits and T76-equipment for drilling the shallow holes. Monitoring pipes (PVC, 60/52 mm) were lowered into the holes inside the casings. The monitoring pipes consist of a lower section of riser pipe, a middle section of screen pipe and an upper section of riser pipe. The screen pipe slot size is 0.3 mm and the length of the screen section is two metres. Protective stainless steel covers with lock-up caps were installed around the monitoring tubes and the shallow drillholes. In addition to the installation of the tubes, the work included water level measurements after installation. The core samples of the shallow drillholes were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. (orig.)

The Olkiluoto 3 project

International Nuclear Information System (INIS)

Knoche, Ph.

2009-01-01

This series of slides presents the Olkiluoto 3 project involving the EPR (European Pressurized water Reactor). This EPR is the first reactor of third generation to have be put into construction. The contract was signed between the Areva-Siemens consortium and the Tvo Finn company in december 2003. The construction of the first-off reactor is always a big challenge but also opens the way for its industrial development as it brings knowledge and experience: Olkiluoto is the first international licensing of the EPR, a valuable feedback experience has been acquired on both the fabrication of the primary components and the qualification of the suppliers. A point on the state of the construction works is made at the first term 2009. (A.C.)

Assessing the velocity of the groundwater flow in bedrock fractures

International Nuclear Information System (INIS)

Taivassalo, V.; Poteri, A.

1994-10-01

Teollisuuden Voima Oy (TVO) is studying the crystalline bedrock in Finland for the final disposal of the spent nuclear fuel from its two reactors in Olkiluoto. Preliminary site investigations for five areas were carried out during 1987-1992. One part of the investigation programme was three-dimensional groundwater flow modelling. The numerical site-specific flow simulations were based on the concept of an equivalent porous continuum. The results include hydraulic head distributions, average groundwater flow rate routes. In this study, a novel approach was developed to evaluate the velocities of the water particles flowing in the fractured bedrock. (17 refs., 15 figs., 5 tabs.)

Environment studies in the Olkiluoto area

International Nuclear Information System (INIS)

Ikonen, A.T.K.; Kaapu, J.; Lehtonen, K.; Mattila, J.; Raeisaenen, R.; Turkki, H.; Sauvonsaari, J.

2003-04-01

In the report, different aspects of environmental status of the Olkiluoto area, an island with the near-sea in the Finnish coast of the Baltic Sea, are described by five topical papers. Regarding animal-life, Olkiluoto represents a typical seashore area of southwestern Finland dominated by rocky hills and commercial forests. In the literature and interview study of local hunters, locally dominant mammal and bird species are identified. No threatened or endangered mammals species were found on the island, and only few bird species in Olkiluoto have a high conservation value. The sea area off Olkiluoto is rather shallow and the water mixing conditions are favourable. The quality and biological production of the water are affected by the general state of the Bothian Sea, the loading brought by the Eurajoki and Lapinjoki Rivers and local wastewaters. Also the cooling waters from the local nuclear power plant impact the sea environment. The bottom vegetation varies from an algae-dominant to a vascular-plantdominant community. Amount of benthic fauna and its species composition has varied considerably, due to both variations of the quality of the bottom and eutrophication. The Eurajoki River represents the second largest river system in southwestern Finland. At its upper reaches, the river is classified as clean and suitable for recreational use. Intermittently, additional waters rich in nutrients flow into the river from ditches and tributaries. Diffuse pollution and the wastewaters of riverside municipalities and industry affect on the water of the lower course, where it is only mildly contaminated, hygienically fairly good and satisfactory for recreational use. The benthic fauna of the river is composed of oligochaetes, clams, leeches and larvae. The fish reserve is versatile in places due to stocking. The Eurajoensalmi Strait, the inlet of the river, is a transitional zone between the river and further sea environments. In the offshore area facing Olkiluoto, there

Core drilling of drillhole ONK-PVA11 in ONKALO at Olkiluoto 2014

Energy Technology Data Exchange (ETDEWEB)

Toropainen, V. [Drillcon SMOY, Espoo (Finland)

2014-12-15

Suomen Malmi Oy (Smoy) core drilled a drillhole for groundwater monitoring station in ONKALO at Eurajoki, Olkiluoto in 2014. The groundwater monitoring stations are used for monitoring changes in groundwater conditions. The drillhole ONK-PVA11 was drilled in February 2014. The length of the drillhole is 30.05 metres. The drillhole is 75.7 mm by diameter. The drillhole ONK-PVA11 was drilled in the left wall of the ONK-TT-4399 (tunnel chainage 50) between the demonstration tunnel ONK-TDT-4399-44 and 56 openings. The hydraulic DE 130 drilling rig was used. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. The drillhole was measured with EMS deviation survey tool. In addition to drilling the drillcore was logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillcore are veined gneiss, diatexitic gneiss and pegmatitic granite. The average fracture frequency in drill core is 2.3 pcs/m and the average RQD value 95.2 %. (orig.)

Core drilling of drillhole ONK-PVA11 in ONKALO at Olkiluoto 2014

International Nuclear Information System (INIS)

Toropainen, V.

2014-12-01

Suomen Malmi Oy (Smoy) core drilled a drillhole for groundwater monitoring station in ONKALO at Eurajoki, Olkiluoto in 2014. The groundwater monitoring stations are used for monitoring changes in groundwater conditions. The drillhole ONK-PVA11 was drilled in February 2014. The length of the drillhole is 30.05 metres. The drillhole is 75.7 mm by diameter. The drillhole ONK-PVA11 was drilled in the left wall of the ONK-TT-4399 (tunnel chainage 50) between the demonstration tunnel ONK-TDT-4399-44 and 56 openings. The hydraulic DE 130 drilling rig was used. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. The drillhole was measured with EMS deviation survey tool. In addition to drilling the drillcore was logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillcore are veined gneiss, diatexitic gneiss and pegmatitic granite. The average fracture frequency in drill core is 2.3 pcs/m and the average RQD value 95.2 %. (orig.)

Forest soil survey and mapping of the nutrient status of the vegetation on Olkiluoto island. Results from the first inventory on the FEH plots

International Nuclear Information System (INIS)

Tamminen, P.; Aro, A.; Salemaa, M.

2007-09-01

The aim of the inventory was to determine the status of the forest soils and to map the current nutrient status of forest vegetation on Olkiluoto Island in order to create a basis for monitoring future changes in the forests and to provide data for a biospheric description of the island. The study was carried out on 94 FEH plots, which were selected from the forest extensive monitoring network (FET plots) on the basis of the forest site type distribution and tree stand characteristics measured on the island during 2002 - 2004. Forest soils on Olkiluoto are very young and typical of soils along the Finnish coast, i.e. stony or shallow soils overlying bedrock, but with more nutrients than the forest soils inland. In addition to nutrients, the heavy metal concentrations are clearly higher on Olkiluoto than the average values for Finnish forest soils. The soil in the alder stands growing along the seashore is different from the other soils on Olkiluoto and the control soils inland. These soils are less acidic and have large reserves of sodium, magnesium and nitrogen. Macronutrient concentrations in vascular plant species were relatively similar to those reported for Southern Finland. However, it is obvious that the accumulation of particulate material on the vegetation, especially on forest floor bryophytes, has increased due to emissions derived from the construction of roads, drilling and rock crushing, as well as the other industrial activities on Olkiluoto Island. Leaf and needle analysis indicated that the tree stands had, in the main, a good nutrient status on Olkiluoto Island. The surveying methods used on Olkiluoto are better suited to detect systematic changes over a larger area or within a group of sample plots than the changes on individual plots. (orig.)

Results of monitoring at Olkiluoto in 2013, rock mechanics

Energy Technology Data Exchange (ETDEWEB)

Johansson, E. (ed.) [Saanio and Riekkola Oy, Helsinki (Finland)

2014-10-15

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2013 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations made in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 21 triaxial sensors. Five stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2013. The number of located events (436) was slightly more than in 2012, but much less than in 2011. Nearly half of the observed explosions (237) in 2013 occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (137). One small induced earthquake (M{sub L} = -1.8) was detected at the depth of 429 m and was probably associated with smaller branches of the brittle fracture zone (OL-BFZ045). According to the seismic monitoring the rock mass has been stable in 2013. The local GPS network consists of 18 stations. Six new stations were set up for permanent tracking during 2013 and in total 12 permanent stations are now operating continuously. Manual measurements were carried out twice in 2013. Most of the inner network baselines showed very small motions as in the previous years: 75% of change rates were smaller than 0.10 mm/y. Roughly one third of the change rates are statistically significant. The surface levelling network currently consists of 87 fixed measuring points. During 2013 all the measuring loops were measured. The results indicated local subsidence area in the ONKALO loop and the rising area in the VLJ loop. Mean deformation rate has been +0.05 mm/y. Only elevation of one benchmark in the GPS station loop has changed more than one millimetre. The continuous displacement measurements in the technical rooms

Results of monitoring at Olkiluoto in 2013, rock mechanics

International Nuclear Information System (INIS)

Johansson, E.

2014-10-01

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2013 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations made in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 21 triaxial sensors. Five stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2013. The number of located events (436) was slightly more than in 2012, but much less than in 2011. Nearly half of the observed explosions (237) in 2013 occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (137). One small induced earthquake (M L = -1.8) was detected at the depth of 429 m and was probably associated with smaller branches of the brittle fracture zone (OL-BFZ045). According to the seismic monitoring the rock mass has been stable in 2013. The local GPS network consists of 18 stations. Six new stations were set up for permanent tracking during 2013 and in total 12 permanent stations are now operating continuously. Manual measurements were carried out twice in 2013. Most of the inner network baselines showed very small motions as in the previous years: 75% of change rates were smaller than 0.10 mm/y. Roughly one third of the change rates are statistically significant. The surface levelling network currently consists of 87 fixed measuring points. During 2013 all the measuring loops were measured. The results indicated local subsidence area in the ONKALO loop and the rising area in the VLJ loop. Mean deformation rate has been +0.05 mm/y. Only elevation of one benchmark in the GPS station loop has changed more than one millimetre. The continuous displacement measurements in the technical rooms of

Posiva safety case hydrogeochemical evolution of the Olkiluoto site

Energy Technology Data Exchange (ETDEWEB)

Trinchero, P.; Roman-Ross, G.; Maia, F.; Molinero, J. [Amphos 21 Consulting S.L., Barcelona (Spain)

2014-03-15

The goal of the present work is to assess the hydrochemical evolution and related changes in the buffering capacity of the Olkiluoto site using reactive transport models. The analysis covers a number of operational-related and climatic-related modelling periods that take place during a glacial cycle; namely, the present conditions with the open repository (Operational Period), the post-closure conditions (Temperate Period) and a stage of the glacial cycle representative of the ice sheet retreat phase (Melting Period). With the aim of reproducing the interplay between the hydrodynamic and geochemical processes, the reactive transport calculations summarised in this document integrate the results of a hydrogeological model with a number of geochemical reactions whose parameterisation relies on previous site investigation studies. The conceptual model on which the study is based, assumes that the hydrochemical evolution of the groundwater at repository depth is the result of infiltration processes from the surface of the domain to the repository. The infiltration occurs along flowpaths through deformation zones and fractures in the bedrock. The infiltrating water, in turn, undergo geochemical reactions with the rock and minerals, namely calcite and iron sulphide precipitation/dissolution, kinetic dissolution of aluminosilicates, cation exchange and aqueous redox reactions. Mass exchange between the transmissive fractures and the low permeability matrix is simulated using a dual porosity approach for the Temperate and Melting Periods. On the contrary, the Operational Period, which is characterised by high hydraulic gradients with advection being the dominant transport mechanism, is simulated using a single porosity model. In all the reactive transport simulations denoted as 'Base Case', pyrite is assumed to be the main iron sulphide mineral in the fracture filling. A set of sensitivity simulations, denoted as 'Variant Case', has been defined where

Foliation: Geological background, rock mechanics significance, and preliminary investigations at Olkiluoto

International Nuclear Information System (INIS)

Milnes, A.G.; Hudson, J.; Wikstroem, L.; Aaltonen, I.

2006-01-01

A well developed, pervasive foliation is a characteristic feature of the migmatites and gneisses in the Olkiluoto bedrock, and is expected to have a significant influence on the underground construction, the design and layout and the groundwater flow regime of a deep spent nuclear fuel repository. This Working Report reviews the geological background and rock mechanics significance of foliation, and develops a methodology for the systematic acquisition of foliation data in cored boreholes and in tunnels at the Olkiluoto site, to provide the necessary basis for future geological, rock mechanics and hydrogeological modelling. The first part of the methodology concerns foliation characterisation, and develops a characterisation scheme based on two variables: the foliation type (G = gneissic, B = banded, S = schistose), which is a function of mineral composition and degree of smallscale heterogeneity, and the foliation intensity (1 = low, 2 = intermediate, 3 = high), which is a function of the type and intensity of the deformation by which it was produced (under high-grade metamorphic conditions in the core of the Svecofennian orogenic belt). At the suggested reference scales (1 m length of core, 10 m 2 area of tunnel wall), the most representative foliation type and intensity is assessed using a standard set of core photographs, which are included as an Appendix at the end of the report, providing a systematic description in terms of 9 descriptive types (G1, G2, G3, B1, B2, B3, S1, S2, S3). As a further step, the rock mechanics significance of these types is assessed and a rock mechanics foliation (RMF) number is assigned (RMF 0 = no significance, RMF 1, RMF 2 and RMF 3 = low, intermediate and high significance, respectively). The second part of the methodology concerns the orientations of the foliation within the same 1 m core lengths or 10 m2 wall areas, which have been characterised as above. This combined analysis of foliation character and foliation orientation

Future vegetation types and related main processes for Olkiluoto site

International Nuclear Information System (INIS)

Haapanen, R.

2007-07-01

This working report summarizes current knowledge of the land up-lift induced vegetation succession and future vegetation types on Olkiluoto Island and its surroundings. The report is based on generic literature and site-specific studies concerning Olkiluoto Island. Current vegetation on Olkiluoto Island and typical succession lines on different soil types are described, as well as main factors affecting the succession. Most relevant materials on hand are listed. Some problems and possible areas to be emphasized before using the data in modelling work are pointed out. (orig.)

Results of Monitoring at Olkiluoto in 2011. Environment

Energy Technology Data Exchange (ETDEWEB)

Haapanen, A. [Haapanen Forest Consulting, Vanhakylae (Finland)

2012-11-15

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2011. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground rock characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to experiences gained from the modelling work and increased understanding of the site. Monitoring activities in 2011 proceeded according to the plans. The land-use of the island continues to change due to the construction work of OL3, ONKALO and related infrastructure, but the remaining natural environment resembles other coastal locations. The amount of nitrogen in the bulk deposition increased in 2011, whereas that of sulphur decreased. Some litterfall fractions showed higher Al and Fe values than earlier, likely caused by soil dust. Proximity of the sea is seen in wet deposition and soil solution results. Soil solution also reflects the young age of soils. Undestorey vegetation has shown no essential changes during the monitoring period. Mammalian fauna on the island is typical of coastal areas in Southwestern Finland. Game catches vary according to hunting pressure and natural variation in populations. The condition of the nearby sea is affected by the continuous land uplift, the shallowness of the area, the weather conditions, the general condition of the Bothnian Sea, the nutrient and sediment loads

Results of Monitoring at Olkiluoto in 2011. Environment

International Nuclear Information System (INIS)

Haapanen, A.

2012-11-01

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2011. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground rock characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to experiences gained from the modelling work and increased understanding of the site. Monitoring activities in 2011 proceeded according to the plans. The land-use of the island continues to change due to the construction work of OL3, ONKALO and related infrastructure, but the remaining natural environment resembles other coastal locations. The amount of nitrogen in the bulk deposition increased in 2011, whereas that of sulphur decreased. Some litterfall fractions showed higher Al and Fe values than earlier, likely caused by soil dust. Proximity of the sea is seen in wet deposition and soil solution results. Soil solution also reflects the young age of soils. Undestorey vegetation has shown no essential changes during the monitoring period. Mammalian fauna on the island is typical of coastal areas in Southwestern Finland. Game catches vary according to hunting pressure and natural variation in populations. The condition of the nearby sea is affected by the continuous land uplift, the shallowness of the area, the weather conditions, the general condition of the Bothnian Sea, the nutrient and sediment loads

Results of Monitoring at Olkiluoto in 2011. Environment

Energy Technology Data Exchange (ETDEWEB)

Haapanen, A. (ed.) [Haapanen Forest Consulting, Vanhakylae (Finland)

2012-11-15

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2011. These summary reports have been published since 2005. The environmental monitoring system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for monitoring the state of the environment during the construction (and later operation) of ONKALO underground rock characterization facility. Part of the monitoring is performed by the company running the nuclear power plants on the island, Teollisuuden Voima Oy (TVO). Monitoring has been carried out for varying periods of time depending on the sector: some monitoring activities performed by TVO originate from the 1970s and the repository-related environmental monitoring of Olkiluoto from the early 2000s. The monitoring programme evolves according to experiences gained from the modelling work and increased understanding of the site. Monitoring activities in 2011 proceeded according to the plans. The land-use of the island continues to change due to the construction work of OL3, ONKALO and related infrastructure, but the remaining natural environment resembles other coastal locations. The amount of nitrogen in the bulk deposition increased in 2011, whereas that of sulphur decreased. Some litterfall fractions showed higher Al and Fe values than earlier, likely caused by soil dust. Proximity of the sea is seen in wet deposition and soil solution results. Soil solution also reflects the young age of soils. Undestorey vegetation has shown no essential changes during the monitoring period. Mammalian fauna on the island is typical of coastal areas in Southwestern Finland. Game catches vary according to hunting pressure and natural variation in populations. The condition of the nearby sea is affected by the continuous land uplift, the shallowness of the area, the weather conditions, the general condition of the Bothnian Sea, the nutrient and sediment

GPS deformation measurements at Olkiluoto in 2013

International Nuclear Information System (INIS)

Nyberg, S.; Kallio, U.; Koivula, H.

2014-08-01

The Finnish Geodetic Institute has monitored crustal deformations since mid-1990s at Olkiluoto, Kivetty and Romuvaara. The research was focused on the Olkiluoto area in 2001, when Olkiluoto was chosen to the site for the final disposal facility of the spent nuclear fuel. The work and the results of the GPS deformation monitoring at Olkiluoto in 2013 are presented. The measurement consisted of two GPS measurement campaigns, observations at local permanent stations and control markers measurements at four stations. In spring six new stations were set up for permanent tracking. In total 12 permanent stations were operating continuously from April to the end of the year. The residual time series of the stations showed periodic trends up to 3 mm in height and 1 mm in horizontal component relative to the GPS1 station. A few stations were still measured as campaign-based and analysed baseline by baseline. The data from permanent stations (GPS1-GPS9, and GPS13) were included. The analysis of the inner network based on campaign sessions showed very small motions as in previous years: 75 % of change rates are smaller than 0.10 mm/y. Roughly one third of the change rates could be considered statistically significant at 1 % significance level. Statistically significant change rates were estimated for baselines from GPS1 and GPS5. The trends and strains differed at some baselines clearly from the earlier analysis because of different troposphere modelling. The results of the outer network showed the largest difference on the baseline GPS1-GPS11 where the trend decreased from -0.42 mm/y to -0.28 mm/y. The strain pattern of the outer network shows an eastwards motion of GPS1. The estimated strains for the baselines east of GPS1 were -0.03/-0.04 ppm/y. The control marker measurements were carried at the stations GPS1, GPS2, GPS4 and GPS6. A comparison of the results with the previous measurements showed that the distance between control markers at GPS6 continues to increase. Also

GPS deformation measurements at Olkiluoto in 2013

Energy Technology Data Exchange (ETDEWEB)

Nyberg, S.; Kallio, U.; Koivula, H. [Finnish Geodetic Institute, Masala (Finland)

2014-08-15

The Finnish Geodetic Institute has monitored crustal deformations since mid-1990s at Olkiluoto, Kivetty and Romuvaara. The research was focused on the Olkiluoto area in 2001, when Olkiluoto was chosen to the site for the final disposal facility of the spent nuclear fuel. The work and the results of the GPS deformation monitoring at Olkiluoto in 2013 are presented. The measurement consisted of two GPS measurement campaigns, observations at local permanent stations and control markers measurements at four stations. In spring six new stations were set up for permanent tracking. In total 12 permanent stations were operating continuously from April to the end of the year. The residual time series of the stations showed periodic trends up to 3 mm in height and 1 mm in horizontal component relative to the GPS1 station. A few stations were still measured as campaign-based and analysed baseline by baseline. The data from permanent stations (GPS1-GPS9, and GPS13) were included. The analysis of the inner network based on campaign sessions showed very small motions as in previous years: 75 % of change rates are smaller than 0.10 mm/y. Roughly one third of the change rates could be considered statistically significant at 1 % significance level. Statistically significant change rates were estimated for baselines from GPS1 and GPS5. The trends and strains differed at some baselines clearly from the earlier analysis because of different troposphere modelling. The results of the outer network showed the largest difference on the baseline GPS1-GPS11 where the trend decreased from -0.42 mm/y to -0.28 mm/y. The strain pattern of the outer network shows an eastwards motion of GPS1. The estimated strains for the baselines east of GPS1 were -0.03/-0.04 ppm/y. The control marker measurements were carried at the stations GPS1, GPS2, GPS4 and GPS6. A comparison of the results with the previous measurements showed that the distance between control markers at GPS6 continues to increase. Also

Gefinex 400S (Sampo) EM-Soundings at Olkiluoto 2006

International Nuclear Information System (INIS)

Jokinen, T.; Lehtimaeki, J.

2006-08-01

In the beginning of summer 2006 Geological Survey of Finland carried out electromagnetic frequency soundings with Gefinex 400S equipment (called also Sampo) at Onkalo situated in Olkiluoto nuclear power plant area. The same soundings sites were the first time measured and marked in 2004 and repeated in 2005. The aim of the measurements is to monitor the changes of groundwater conditions by the changes of the electric conductivity of the earth at ONKALO and repository area. The measurements form two 1400 m long broadside profiles, which have 200 m mutual distance and 200 m station separation. The profiles have been measured using 200, 500, and 800 m coil separations. The total number of the soundings was 48 but at 8 stations the measurement did not succeed because of strong electromagnetic noise. The numerous power lines and the cables of the area generate local 3-D effects on the sounding curves, but the repeatability of the results is good. However, most suitable for monitoring purposes are the sites without strong 3-D effects. Comparison of results 2004-2006 shows small differences at some sounding sites. (orig.)

Results of monitoring at Olkiluoto in 2005. Environment

International Nuclear Information System (INIS)

Haapanen, R.

2006-08-01

This Working Report presents the main results of Posiva Oy's environmental monitoring programme on Olkiluoto Island in 2005. This is the second annual report. Monitoring has been carried out for varying time periods depending on the sector: some monitoring activities performed by TVO originate from the 1970s, others connected with the construction of the final disposal repository for nuclear waste and the underground research facility ONKALO have just started. The system supervised by Posiva Oy produces input for biosphere modelling for long-term safety purposes as well as for environmental impact analyses. In 2005 the deposition collectors and nearby needles caught some dust from the rock piling and crushing activities and traffic. Noise was another clear effect, originating mostly from OL3 construction, rock piling and crushing area and the concrete station. The studies further confirmed that the vegetation, forests, soils and animal life are typical of a coastal region within the same vegetation zone. The nearby marine environment is affected by the cooling water from the nuclear power plant, to varying extents depending on the organism and the distance. Monitoring of marine environments as well as radionuclide analyses at the moment produce reference data for the future and create a basis for the construction of a model, as no input from Posiva's activities will influence these areas for a long time. (orig.)

Baseline conditions at Olkiluoto

International Nuclear Information System (INIS)

2003-09-01

The main purpose of this report is to establish a reference point - defined as the data collected up until the end of year 2002 - for the coming phases of the Finnish spent nuclear fuel disposal programme. The focus is: to define the current surface and underground conditions at the site, both as regards the properties for which a change is expected and for the properties which are of particular interest for long-term safety or environmental impact; to establish, as far as possible, the natural fluctuation of properties that are potentially affected by construction of the underground laboratory, the ONKALO, and to provide references to data on parameters or use in model development and testing and to use models to assist in understanding and interpreting the data. The emphasis of the baseline description is on bedrock characteristics that are relevant to the long-term safety of a spent fuel repository and, hence, to include the hydrogeological, hydrogeochemical, rock mechanical, tectonic and seismic conditions of the site. The construction of the ONKALO will also affect some conditions on the surface, and, therefore, a description of the main characteristics of the nature and the man-made constructions at Olkiluoto is also given. This report is primarily a road map to the available information on the prevailing conditions at the Olkiluoto site and a framework for understanding of data collected. Hence, it refers to numerous available background reports and other archived information produced over the past 20 years or more, and forms a recapitulation and revaluation of the characterisation data of the Olkiluoto site. (orig.)

Game statistics for the island of Olkiluoto in 2005-2006

International Nuclear Information System (INIS)

Oja, S.

2006-11-01

The game statistics for the island of Olkiluoto was updated in February 2006. The estimate of game populations in Olkiluoto was done on the basis of interviews of local hunters and available statistical materials. The collected data were compared to earlier studies of game animals done in Olkiluoto. The populations of Elk and White-tailed Deer are stable, and the population of Roe Deer is increasing significantly. The populations of small mammal predators (American Mink, Raccoon Dog, Red Fox) are very high level, despite of intensive hunting. Other game animals like waterfowls are hunted moderately and the amount of catches are small. (orig.)

Studies on the aquatic environment at Olkiluoto and reference area. 1: Olkiluoto, reference lakes and Eurajoki and Lapijoki rivers in 2009-2010

Energy Technology Data Exchange (ETDEWEB)

Kangasniemi, V. [Environmental Research and Assessment EnviroCase Ltd., Pori (Finland); Helin, J.

2014-03-15

This working report presents the first results of a sampling campaign at Olkiluoto and reference lakes and rivers selected to resemble the aquatic systems expected to form at the site in the future with the post-glacial crustal rebound (land uplift). In 2009-2010, the aim of the studies was to improve the knowledge of the aquatic systems and to produce input data to the safety case for the spent nuclear fuel repository at Olkiluoto. The first main objective was to estimate the areal biomass distribution and measure the dimensions of characteristic aquatic plants and animals. Another objective was to estimate the transfer of different elements from water to the aquatic organisms paying special attention on key elements (Ag, Cl, I, Mo, Nb and Se) in the dose assessment within the safety case. Surface water, sediment, macrophyte, fish and macrobenthos samples were collected from the Olkiluoto coastal area and from the reference lakes for biomass and dimension measurements and analysis of element concentration. Water-to-biota concentration ratios were estimated for the coastal area and for the reference lakes. From rivers, only water samples were collected at this stage. In 2009-2010, sampling procedures and pre-treatment methods were developed and analytical methods were optimised. Thus, the results reported here are indicative by their nature. After 2010, the studies have been continued with better established methods, and the more recent results will be reported later. (orig.)

Gefinex 400S (SAMPO) EM-soundings at Olkiluoto 2009

International Nuclear Information System (INIS)

Jokinen, T.; Lehtimaeki, J.; Korhonen, K.

2009-09-01

In the beginning of June 2009 Geological Survey of Finland (GTK) carried out electromagnetic (EM) frequency soundings with Gefinex 400S equipment (Sampo) in the vicinity of ONKALO at the Olkiluoto site investigation area. The EM-monitoring sounding program started in 2004 and has been repeated since yearly in the same season. The aim of the study is to monitor the variations of the groundwater properties down to 500 m depth by the changes of the electric conductivity of the earth at ONKALO and repository area. The original measurement grid was based on two 1400 m long broadside profiles, which have 200 m mutual distance and 200 m station separation. The receiver and transmitter sites are marked with stakes and the profiles were measured using 200, 500, and 800 m coil separations. The measurement program was revised in 2007 and then again in 2009. Now 15 noisy soundings were removed from the program and 3 new points were selected from the area to the east from ONKALO. The new receiver/transmitter sites, called ABC-points were marked with stakes and the points were measured using transmitter-receiver separations 200, 400 and 800 meters. In 2009 the new EM-Sampo monitoring program included 28+9 soundings. The numerous power lines and cables in the area generate local disturbances on the sounding curves, but the SN (signal to noise) ratio and the repeatability of the results is reasonably good even with long coil separations. However, most suitable for monitoring purposes are the sites without strong shallow 3D effects. Comparison of the new results to old 2004-2008 surveys shows differences on some ARD (apparent resistivity-depth) curves. Those are mainly results of the modified shallow structures. The changes in groundwater conditions based on the monitoring results seem insignificant. (orig.)

Greenland Analogue Project - Hydraulic properties of deformation zones and fracture domains at Forsmark, Laxemar and Olkiluoto for usage together with Geomodel version 1

International Nuclear Information System (INIS)

Follin, Sven; Stigsson, Martin; Rhen, Ingvar; Engstroem, Jon; Klint, Knut Erik

2011-05-01

The database of the GAP site is under development. In order to meet the data needs of the different modelling teams working with groundwater flow modelling it has been decided to compile trial data sets comprising structural-hydraulic properties suitable for flow modelling on different scales. The properties provided in this report are based on data and groundwater flow modelling studies conducted for three sites located in the Fennoscandian Shield, two of which are studied by SKB, Forsmark and Laxemar, and one by Posiva, Olkiluoto. The provided hydraulic properties provided here are simplified to facilitate a readily usage together with the GAP Geomodel version 1

Greenland Analogue Project - Hydraulic properties of deformation zones and fracture domains at Forsmark, Laxemar and Olkiluoto for usage together with Geomodel version 1

Energy Technology Data Exchange (ETDEWEB)

Follin, Sven (SF GeoLogic AB (Sweden)); Stigsson, Martin (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Rhen, Ingvar (Sweco Environment AB (Sweden)); Engstroem, Jon (Geologian tutkimuskeskus (Finland)); Klint, Knut Erik (De Nationale Geologiske Undersoegelser for Danmark og Groenland (Denmark))

2011-05-15

The database of the GAP site is under development. In order to meet the data needs of the different modelling teams working with groundwater flow modelling it has been decided to compile trial data sets comprising structural-hydraulic properties suitable for flow modelling on different scales. The properties provided in this report are based on data and groundwater flow modelling studies conducted for three sites located in the Fennoscandian Shield, two of which are studied by SKB, Forsmark and Laxemar, and one by Posiva, Olkiluoto. The provided hydraulic properties provided here are simplified to facilitate a readily usage together with the GAP Geomodel version 1.

Bedrock model of the Olkiluoto area

International Nuclear Information System (INIS)

Saksa, P.; Paananen, M.; Paulamaeki, S.; Anttila, P.; Front, K.; Pitkaenen, P.; Hassinen, P.; Ylinen, A.

1993-07-01

Site investigations were carried out at Olkiluoto (in Finland) in 1987-1992 in accordance with an investigation programme drawn up by Teollisuuden Voima Oy (TVO). The site was modelled in terms of rock types, fracturing, fracture structures and geohydrological conditions, the main focus of examination was on fracturing and associated hydraulic conductivity. The various properties of the bedrock structures were classified by means of a three-dimensional model. The descriptions of the models were gathered in a computer system for illustration and storage purposes. The rock types at Olkiluoto are migmatite, which may be divided into mica gneiss and veined gneiss, and also tonalite and coarse-grained migmatite granite (pegmatite). (64 refs., 65 figs.)

Results of monitoring at Olkiluoto in 2007. Hydrology

International Nuclear Information System (INIS)

Vaittinen, T.; Ahokas, H.; Klockars, J.; Nummela, J.; Penttinen, T.; Tammisto, E.; Karvonen, T.

2008-07-01

The impact of the construction of ONKALO is monitored by measuring and observing numerous different parameters related to hydrology, geochemistry, environment, rock mechanics and foreign materials. The hydrological monitoring programme consists of the following parameters: groundwater level, hydraulic head, flow conditions in open boreholes, cross drillhole flow, hydraulic conductivity, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff), infiltration, ground frost, leakages in tunnels, water balance in the tunnel system and in the Korvensuo reservoir. This report focuses on the hydrogeological parameters. Other parameters like precipitation, ground frost etc. will be reported in the environment report. Monitoring has in the main parts been carried out according to plan. The previous monitoring report contained results until the end of 2006, and this report presents results for the year 2007. Cross drillhole measurements were started as new measurements by test measurements. Monitoring measurements will start in 2008. In addition, the water balance of the Korvensuo Reservoir was introduced for the first time. According to the observations made in shallow observation tubes in the overburden and in shallow drillholes in the bedrock, the construction of ONKALO has not caused any certain changes in groundwater level. However, weak indications of a decrease in groundwater level have been observed. The effects on the head deeper in the bedrock have been both short-term and long-term. Short-term changes have been caused by several different investigation activities carried out in the field and by ONKALO as well by as temporary leakages due to the e.g. grouting holes drilled in ONKALO. The order of magnitude of long-term changes, i.e. a decrease in pressure heads near ONKALO, has remained the same as the previous year and the changes are in the order of 1 m. The changes observed in flow conditions in open drillholes

Matrix Pore Water in Low Permeable Crystalline Bedrock: An Archive for the Palaeohydrogeological Evolution of the Olkiluoto Investigation Site

Energy Technology Data Exchange (ETDEWEB)

Eichinger, F. [Hydroisotop GmbH, Schweitenkirchen (Germany); Waber, H. N. [Rock-Water Interaction, Institute of Geological Sciences, University of Bern, Bern (Switzerland); Smellie, J. A.T. [Conterra AB, Stockholm (Sweden)

2013-07-15

Matrix pore water in the connected inter- and intragranular pore space of low permeable crystalline bedrock interacts with flowing fracture groundwater predominately by diffusion. Based on the slow exchange between the two water reservoirs, matrix pore water acts as an archive of past changes in fracture groundwater compositions and thus of the palaeohydrological history of a site. Matrix pore water of crystalline bedrock from the olkiluoto investigation site (SW Finland) was characterised using the stable water isotopes ({delta}{sup 18}O, {delta}{sup 2}H), combined with the concentrations of dissolved chloride and bromide as natural tracers. The comparison of tracer concentrations in pore water and present day fracture groundwater suggest for the pore water the presence of old, dilute meteoric water components that infiltrated into the fractures during various warm climate stages. These different meteoric components can be discerned based on the diffusion distance between the two reservoirs and brought into context with the palaeohydrological evolution of the site. (author)

The use of gamma spectrometry in mapping alteration zones in Olkiluoto

International Nuclear Information System (INIS)

Ojala, J.V.; Turunen, P.; Eilu, P.; Julkunen, A.; Gehoer, S.

2007-08-01

In the Olkiluoto site, a detailed gammaspectrometry log from the drill hole OL-KR27 was used to estimate the concentrations of K, Th and U. The gamma spectrometry results, lithological variations, and kaolinite and illite alteration visually mapped from the drill hole were compared. The result indicate that the Th/K ratio correlates best with lithology and that, in most cases, the changes in the ratio indicate lithological contacts and rising or falling trends of Th/K ratio with some peaks have some correlation with the kaolinite-illite alteration. From the result it is suggested that that very variable Th/K ratio is a reasonably good indicator of alteration zones even in the migmatic gneiss area in the Olkiluoto site. (orig.)

Simulations of permafrost evolution at Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Hartikainen, J. [Aalto Univ., Espoo (Finland)

2013-07-15

This report provides numerical estimations of the evolution of permafrost and perennially frozen ground at Olkiluoto on time-scales of 60,000 and 125,000 years using Olkiluoto's site-specific information on time histories of ground level temperatures, ice sheet thickness, basal conditions, shoreline migration, soil and vegetation cover as well as heat generation from the spent fuel at a depth of 420 metres. When considering environmental conditions akin to the last glacial cycle for a 125,000 years long period, the maximum permafrost depth over the repository area can exceed the depth of 300 m and the maximum depth of perennially frozen ground the depth of 270 m. If Olkiluoto, after a 50,000 years long temperate phase of boreal climate, was subjected to a 10,000 years long periglacial period with air temperature decreased between -5 deg C and -10 deg C, the maximum permafrost depth would range between 60 and 240 m and the maximum depth of perennially frozen ground between 50 and 220 m. Furthermore, permafrost would reach the repository depth in 10,000 years, if the air temperature was lowered down to -15 deg C and the ground surface had a very thin vegetation and snow cover. Alternatively, if Olkiluoto experienced a 125,000 years long glacial cycle with a very long periglacial periods of low air temperatures and thin vegetation and snow cover and without any ice sheet development, permafrost would reach the depth of 400 m in 98,000 years and perennially frozen ground in 101,000 years. The areal distribution of permafrost and perennially frozen ground are broadly affected by the snow cover, lakes and the peat areas, especially when an extensive peat growth occurs. The lack of snow cover can enhance the evolution of the maximum depth of permafrost and perennially frozen ground by over 50 %. In addition, ground thermal conditions and the heat generation from the spent fuel modify the spatial and temporal development of permafrost and perennially frozen ground. A

Simulations of permafrost evolution at Olkiluoto

International Nuclear Information System (INIS)

Hartikainen, J.

2013-07-01

This report provides numerical estimations of the evolution of permafrost and perennially frozen ground at Olkiluoto on time-scales of 60,000 and 125,000 years using Olkiluoto's site-specific information on time histories of ground level temperatures, ice sheet thickness, basal conditions, shoreline migration, soil and vegetation cover as well as heat generation from the spent fuel at a depth of 420 metres. When considering environmental conditions akin to the last glacial cycle for a 125,000 years long period, the maximum permafrost depth over the repository area can exceed the depth of 300 m and the maximum depth of perennially frozen ground the depth of 270 m. If Olkiluoto, after a 50,000 years long temperate phase of boreal climate, was subjected to a 10,000 years long periglacial period with air temperature decreased between -5 deg C and -10 deg C, the maximum permafrost depth would range between 60 and 240 m and the maximum depth of perennially frozen ground between 50 and 220 m. Furthermore, permafrost would reach the repository depth in 10,000 years, if the air temperature was lowered down to -15 deg C and the ground surface had a very thin vegetation and snow cover. Alternatively, if Olkiluoto experienced a 125,000 years long glacial cycle with a very long periglacial periods of low air temperatures and thin vegetation and snow cover and without any ice sheet development, permafrost would reach the depth of 400 m in 98,000 years and perennially frozen ground in 101,000 years. The areal distribution of permafrost and perennially frozen ground are broadly affected by the snow cover, lakes and the peat areas, especially when an extensive peat growth occurs. The lack of snow cover can enhance the evolution of the maximum depth of permafrost and perennially frozen ground by over 50 %. In addition, ground thermal conditions and the heat generation from the spent fuel modify the spatial and temporal development of permafrost and perennially frozen ground. A

An approach to palaeoseismicity in the Olkiluoto (sea) area during the early holocene

International Nuclear Information System (INIS)

Hutri, K.L.

2007-06-01

Olkiluoto Island is situated in the northern Baltic Sea, near the southwestern coast of Finland, and is the proposed location of a spent nuclear fuel repository. This study examined Holocene palaeoseismicity in the Olkiluoto area and in the surrounding sea areas by computer simulations together with acoustic-seismic, sedimentological and dating methods. The most abundant rock type on the island is migmatic mica gneiss, intruded by tonalites, granodiorites and granites. The surrounding Baltic Sea seabed consists of Palaeoproterozoic crystalline bedrock, which is to a great extent covered by younger Mesoproterozoic sedimentary rocks. The area contains several ancient deep-seated fracture zones that divide it into bedrock blocks. The response of bedrock at the Olkiluoto site was modelled considering four future ice-age scenarios. Each scenario produced shear displacements of fractures with different times of occurrence and varying recovery rates. Generally, the larger the maximum ice load, the larger were the permanent shear displacements. For a basic case, the maximum shear displacements were a few centimetres at the proposed nuclear waste repository level, at proximately 500 m b.s.l. high-resolution, low-frequency echo-sounding was used to examine the Holocene submarine sedimentary structures and possible direct and indirect indicators of palaeoseismic activity in the northern Baltic Sea. Echo-sounding profiles of Holocene submarine sediments revealed slides and slumps, normal faults, debris flows and turbidite-type structures. The profiles also showed pockmarks and other structures related to gas or groundwater seepages, which might be related to fracture zone activation. Evidence of postglacial reactivation in the study area was derived from the spatial occurrence of some of the structures, especial the faults and the seepages, in the vicinity of some old bedrock fracture zones. Palaeoseismic event(s) (a single or several events) in the Olkiluoto area were dated

Core drilling of deep drillhole OL-KR48 at Olkiluoto in Eurajoki 2007

International Nuclear Information System (INIS)

Toropainen, V.

2008-01-01

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 530.11 m deep drillhole (identification number OL-KR48) with a diameter of 75.7 mm at Olkiluoto in summer 2007. This drillhole was aimed to get additional information of the quality of bedrock in the area, where a new shaft with a diameter of 3.5 m is planned. The drillhole is nearly vertical, and its deviation was minimized with directional drilling. The drillhole requires cleaning and stabilization for down the hole measurements. To obtain more information about bedrock and groundwater properties, a set of monitoring measurements and samplings from the drilling and returning water was carried out during. Both the volume and the electric conductivity of the returning and drilling waters were recorded. The drill rig was computer controlled and recorded drilling parameters. Sodium fluorescein was used as a label agent in the drilling water. The total volume of the used drilling and washing water was 438 m 3 . Measured volume of the returning water was 123 m 3 . The deviation of the drillhole was measured with the deviation measuring instruments DeviTool and EMS. The results of the EMS measurements indicate that the drillhole deviates 2.51 m north and 0.51 m west from the target point at the drillhole depth of 528 m. Results of DeviTool indicate deviation of 1.44 m north and 0.40 m west at depth of 530 m. Uniaxial compressive strength (113.0 Mpa), Young's Modulus (36.2 GPa) and

Surface and near-surface hydrological model of Olkiluoto island

International Nuclear Information System (INIS)

Karvonen, T.

2008-04-01

The aim of the study was to develop a 3D-model that calculates the overall water balance components of Olkiluoto Island in the present-day condition utilizing the existing extensive data sets available. The model links the unsaturated and saturated soil water in the overburden and groundwater in bedrock to a continuous pressure system. The parameterization of land use and vegetation was done in such a way that the model can later on be used for description of the past evolution of the overburden hydrology at the site and overburden's hydrological evolution in the future. Measured groundwater level in overburden tubes, pressure heads in shallow bedrock holes, snow depth, soil temperature, frost depth and discharge measurements were used in assessing the performance of the models in the calibration period (01.05.2001- 31.12.2005). Computed groundwater level variation can be characterized by variables ΔH MEAS and ΔH COMP , which are the difference between maximum and minimum measured and computed groundwater level value during the calibration period. Average ΔH MEAS for all tubes located in fine-textured till soil was 1.99 m and the corresponding computed value ΔH COMP was 1.83 m. Average ΔH MEAS for all tubes located in sandy till soil was 2.12 m and the corresponding computed value ΔH COMP was 1.93 m. The computed results indicate that in future studies it is necessary to divide the two most important soil types into several subclasses. In the present study the uncertainty and sensitivity analysis was carried out through a parameter uncertainty framework known as GLUE. According to the uncertainty analysis the average yearly runoff was around 175 mm a -1 and 50 % confidence limits were 155 and 195 mm a -1 . Measured average yearly runoff during the calibration period was 190 mm a -1 . Average yearly evapotranspiration estimate was 310 mm a -1 and the 50 % confidence limits were 290 and 330 mm a -1 . Average value for recharge through the bedrock system was 1

Petrology of Olkiluoto

International Nuclear Information System (INIS)

Kaerki, A.; Paulamaeki, S.

2006-11-01

The rocks of Olkiluoto fall into four main groups: (1) gneisses, (2) migmatitic gneisses, (3) TGG-gneisses (TGG = tonalite-granodiorite-granite) and 4) pegmatitic granites. In addition, narrow diabase dykes occur sporadically. The gneisses include homogeneous mica-bearing quartz gneisses, banded mica gneisses and hornblende or pyroxene-bearing mafic gneisses. The migmatitic gneisses, which typically comprise 20 - 40% leucosome, can be divided into three subgroups in terms of their migmatite structures: veined gneisses, stromatic gneisses and diatexitic gneisses. The leucosomes of the veined gneisses show vein-like, more or less elongated traces with some features similar to augen structures. Planar leucosome layers characterize the stromatic gneisses, while the migmatite structure of the diatexitic gneisses is asymmetric and irregular. The TGG gneisses are medium-grained, relatively homogeneous rocks that can show a blastomylonitic foliation, but they can also resemble plutonic, unfoliated rocks. The pegmatitic granites are leucocratic, very coarse-grained rocks, which may contain large garnet, tourmaline and cordierite phenocrysts. Mica gneiss inclusions are typical of the larger pegmatitic bodies. Gneisses, which are weakly or not at all migmatitic, make ca. 9% of the bedrock. Migmatitic gneisses make up over 64% of the volume of the Olkiluoto bedrock, with the veined gneisses accounting for 43%, the stromatic gneisses for 0.4% and the diatexitic gneisses for 21%, based on drill core logging. Of the remaining lithologies, TGG gneisses constitute 8% and pegmatitic granites almost 20% by volume. The supracrustal rocks of Olkiluoto can be divided into four series by reference to whole rock chemical composition: a T series, S series, P series and basic, volcanogenic gneisses. Rocks of the T, S and P series seem to make up 42%, 12% and 26%, respectively, of the volume of central part of the island of Olkiluoto, in addition to which, pegmatitic granites and diabases

Migmatites and migmatite-like rocks of Olkiluoto

International Nuclear Information System (INIS)

Kaerki, A.

2015-02-01

Bedrock of the Olkiluoto Island in the western end of the Palaeoproterozoic Svecofennian Accretionary Arc Complex, SW Finland is composed of high-grade metamorphic pelites, arenites and intermediate, arc type metavolcanic rocks intruded by granodioritic to tonalitic plutonic rocks. Regional metamorphism culminated with voluminous migmatization in the temperature of 660 - 700 deg C and relatively low pressure of about 3.5 - 4 kbar. The end result of polyphase metamorphism and deformation is a metamorphic rock succession composed of diverse migmatite rocks, metatexites and diatexites. Metatexites are migmatites in which several, discrete components can be detected, and in which the paleosome with some pre-partial-melting textures is identifiable. Diatexites are more advanced migmatites in which the pre-migmatization structures are often totally destroyed and the rock is dominated by different neosome components meaning leucosome, melanosome or mesosome. Based on the migmatite structures the metatexites of Olkiluoto have been classified into six subgroups. Dike-structured metatexites are composed of well preserved paleosome intruded by one single set of narrow, subparallel leucosome dikes which cover ca. 5 - 10 % of the whole rock volume. Net-structure is composed of a network of narrow leucosome dikes which show a reticulated structure in a plane section and cover less than 30 % of the whole rock volume. Breccia-structure is composed of angular or rounded paleosome blocks surrounded by moderate amount of leucosome. Patch-structure is composed of irregular leucosome patches which intruded the well preserved paleosome and compose typically 20 - 70 % of the rock volume. Layer-structure is characterized by more or less regular leucosome dikes sub-parallel to the foliation of the well preserved paleosome. Vein-structured metatexites and also diatexites include a set of pipe-like, longish leucosome veins most probably generated by synchronous melting and deformation

Migmatites and migmatite-like rocks of Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Kaerki, A. [Kivitieto Oy, Oulu (Finland)

2015-02-15

Bedrock of the Olkiluoto Island in the western end of the Palaeoproterozoic Svecofennian Accretionary Arc Complex, SW Finland is composed of high-grade metamorphic pelites, arenites and intermediate, arc type metavolcanic rocks intruded by granodioritic to tonalitic plutonic rocks. Regional metamorphism culminated with voluminous migmatization in the temperature of 660 - 700 deg C and relatively low pressure of about 3.5 - 4 kbar. The end result of polyphase metamorphism and deformation is a metamorphic rock succession composed of diverse migmatite rocks, metatexites and diatexites. Metatexites are migmatites in which several, discrete components can be detected, and in which the paleosome with some pre-partial-melting textures is identifiable. Diatexites are more advanced migmatites in which the pre-migmatization structures are often totally destroyed and the rock is dominated by different neosome components meaning leucosome, melanosome or mesosome. Based on the migmatite structures the metatexites of Olkiluoto have been classified into six subgroups. Dike-structured metatexites are composed of well preserved paleosome intruded by one single set of narrow, subparallel leucosome dikes which cover ca. 5 - 10 % of the whole rock volume. Net-structure is composed of a network of narrow leucosome dikes which show a reticulated structure in a plane section and cover less than 30 % of the whole rock volume. Breccia-structure is composed of angular or rounded paleosome blocks surrounded by moderate amount of leucosome. Patch-structure is composed of irregular leucosome patches which intruded the well preserved paleosome and compose typically 20 - 70 % of the rock volume. Layer-structure is characterized by more or less regular leucosome dikes sub-parallel to the foliation of the well preserved paleosome. Vein-structured metatexites and also diatexites include a set of pipe-like, longish leucosome veins most probably generated by synchronous melting and deformation

Core drilling of deep drillhole OL-KR54 at Olkiluoto in Eurajoki 2010

International Nuclear Information System (INIS)

Toropainen, V.

2010-11-01

As a part of the confirming site investigations at Olkiluoto, Suomen Malmi Oy (Smoy) core drilled a 500.18 m deep drillhole with a diameter of 75.7 mm at Olkiluoto in July - August 2010. The identification number of the drillhole is OL-KR54. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling water were recorded. The drill rig was computer controlled and the computer recorded drilling parameters during drilling. The objective of the measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volume of the used drilling, washing and flushing water was 382 m 3 . The measured volume of the returning water in the drillhole was 334 m 3 . The deviation of the drillhole was measured with the deviation measuring instruments EMS and Gyro. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength was 111.5 MPa, the average Young's Modulus was 43.7 GPa and the average Poisson's ratio was 0.17. The main rock types are diatexitic and veined gneisses, pegmatitic granite and mafic gneiss. The average fracture frequency is 1.6 pcs/m and the average RQD value is 97.6 %. Nine fractured zones were penetrated by the drillhole. (orig.)

Significance and estimations of lifetime of natural fracture mineral buffers in the Olkiluoto bedrock

International Nuclear Information System (INIS)

Luukkonen, A.; Pitkaenen, P.; Partamies, S.

2004-03-01

This study attempts to make scenarios what geochemical effects the future underground excavations in the Olkiluoto bedrock have on naturally occurring fracture mineral buffers. The excavations of underground research facilities, and final repository galleries will cause steep hydraulic gradients in the bedrock fractures. These gradients likely draw surficial waters within the fracture network and activate weathering processes deeper in rock fractures than in the natural undisturbed conditions. The studies are concentrated on the meteoric and seawater infiltration in the rock fractures, and on the selected minerals considered significant buffers against pH/redox variations in groundwater. Two approaches to calculate the scenarios are utilised. The equilibrium geochemical calculations consider variety of problems including several surficial water compositions, mixing cases between surficial water types, and couple buffer mineral assemblages. These equilibrium calculations indicate that meteoric water by far presents the most potential hazard for the Olkiluoto fracture minerals. In the calculated cases, seawater and the contamination of meteoric water with seawater during the water infiltration usually improved the performance of mineral buffers compared to the pure meteoric water cases. Of the Olkiluoto fracture minerals, calcite and pyrite turn out to be the most important buffer minerals against dissolved O 2 and low pH in groundwater. The kinetic geochemical approach concentrated on two meteoric water cases infiltrating into a narrow fracture channel. Calculations consider the possibilities that the infiltrating meteoric water is dissolved carbon containing soil water or almost 'distilled' rain water. Pyrite and calcite are taken into account as the buffering minerals. Several simulations are done by varying the recharge water compositions and the flow rates of water. It turns out that as long as volumetric flow rates within the 500-metre-channel considered are in

Sulphide fluxes and concentrations in the spent nuclear fuel repository at Olkiluoto

International Nuclear Information System (INIS)

Wersin, P.; Alt-Epping, P.; Pitkaenen, P.

2014-01-01

Sulphide may act as corrodant for the copper canister in the KBS-3 disposal concept. Sulphide fluxes at repository level are affected by various sources in the host rock, the backfill and the buffer. Hydrogen sulphide is effectively immobilised by Fe to form insoluble iron sulphide minerals. Thus, dissolved sulphide levels in reducing environment and also in Olkiluoto groundwaters are generally low. In zones favourable for sulphate reducing bacteria (SRB), however, temporarily more elevated sulphide concentrations are possible. The sulphate reduction and subsequent iron sulphide precipitation process depends on geochemical conditions, microbial activity and mass transfer of the reactants and is thus highly system-specific. The overall objective of the work presented in this report is to provide a thorough background for the sulphide concentrations and sulphide fluxes in the near field and the far field used in the performance assessment 2012

Simulation of hydraulic disturbances caused by the underground rock characterisation facility in Olkiluoto

International Nuclear Information System (INIS)

Loefman, J.; Meszaros, F.

2005-11-01

The hydraulic disturbances that might result from the open ONKALO tunnel system were assessed by means of site-scale finite element simulations. The details of the construction and operation of the ONKALO was not taken into account in the simulations, but the entire tunnel system was instantly made hydraulically active at the beginning of the simulation and was assumed to be open for 100 years. The inflow of groundwater into the tunnels, the resulting drawdown of the water table, and the upconing of deep saline groundwater were analysed separately by using somewhat different modelling approaches and assumptions. The drawdown of the water table was simulated by employing the free surface approach, in which only the saturated part was included in the modelled volume and the sinking water table constituted the free surface. The tunnel inflows were obtained from the state of equilibrium. The evolution of the salinity distribution was simulated with a time-dependent and coupled (flow and salt transport) model. The simulations showed that without engineering measures (e.g., grouting) to limit inflow of groundwater into the open tunnels, the hydraulic disturbances would be significantly greater than with these measures implemented. The drifts that made up strong sinks in the model, draw groundwater from all directions in the bedrock. Most of inflow (330-1100 l/min) would come from the well-conductive subhorizontal fracture zones intersected by the access tunnel and the shaft. The water table might sink locally to a depth of about 200 metres and the depressed area extend over the Olkiluoto Island. The results also indicated that the salinity of the groundwater could gradually rise around and below the drifts, and locally concentration (TDS) may rise from 22 g/l up to over 50 g/l in the vicinity of the tunnels. The disturbances can significantly be reduced by the grouting of rock. In the case of tight grouting the depression of the water table was confined to the immediate

Results of monitoring at Olkiluoto in 2010. Hydrogeochemistry

Energy Technology Data Exchange (ETDEWEB)

Penttinen, T. [Poeyry Finland Oy, Espoo (Finland); Partamies, S. [VTT Technical Research Centre of Finland, Espoo (Finland); Lahdenperae, A.-M. [Saanio and Riekkola Oy, Helsinki (Finland); Lamminmaeki, T.; Lehtinen, A.; Sireeni, S.

2013-07-15

The construction work of underground research facility ONKALO started in the autumn 2004. Possible changes caused by the construction of the disposal facility in the chemical environment in shallow and deep groundwaters are monitored on a regular basis. This report presents the hydrogeochemical monitoring measurements and observations made in 2010. A total of 75 shallow groundwater samples (29 monitoring and 46 infiltration area) were taken in 2010.

Environmental Impact Assessment for Olkiluoto 4 Nuclear Power Plant Unit in Finland

International Nuclear Information System (INIS)

Dersten, Riitta; Gahmberg, Sini; Takala, Jenni

2008-01-01

In order to improve its readiness for constructing additional production capacity, Teollisuuden Voima Oyj (TVO) initiated in spring 2007 the environmental impact assessment procedure (EIA procedure) concerning a new nuclear power plant unit that would possibly be located at Olkiluoto. When assessing the environmental impacts of the Olkiluoto nuclear power plant extension project, the present state of the environment was first examined, and after that, the changes caused by the projects as well as their significance were assessed, taking into account the combined impacts of the operations at Olkiluoto. The environmental impact assessment for the planned nuclear power plant unit covers the entire life cycle of the plant unit. (authors)

Environmental Impact Assessment for Olkiluoto 4 Nuclear Power Plant Unit in Finland

Energy Technology Data Exchange (ETDEWEB)

Dersten, Riitta; Gahmberg, Sini; Takala, Jenni [Teollisuuden Voima Oyj, Olkiluoto, FI-27160 Eurajoki (Finland)

2008-07-01

In order to improve its readiness for constructing additional production capacity, Teollisuuden Voima Oyj (TVO) initiated in spring 2007 the environmental impact assessment procedure (EIA procedure) concerning a new nuclear power plant unit that would possibly be located at Olkiluoto. When assessing the environmental impacts of the Olkiluoto nuclear power plant extension project, the present state of the environment was first examined, and after that, the changes caused by the projects as well as their significance were assessed, taking into account the combined impacts of the operations at Olkiluoto. The environmental impact assessment for the planned nuclear power plant unit covers the entire life cycle of the plant unit. (authors)

Gefinex 400S (Sampo) EM-Soundings at Olkiluoto 2007

International Nuclear Information System (INIS)

Jokinen, T.; Lehtimaeki, J.

2007-09-01

In the beginning of June 2007 Geological Survey of Finland carried out electromagnetic frequency soundings with Gefinex 400S equipment (Sampo) at Onkalo situated in Olkiluoto nuclear power plant area. The same soundings sites were the first time measured and marked in 2004 and repeated after it yearly. The aim of the measurements is to monitor the changes of groundwater conditions by the changes of the electric conductivity of the earth at ONKALO and repository area. The measurements form two 1400 m long broadside profiles, which have 200 m mutual distance and 200 m station separation. The profiles have been measured using 200, 500, and 800 m coil separations. The total number of the soundings stations is 48. In 2007 at 8 sounding stations the transmitter and/or receiver sites were changed and the line L11.400 was substituted by line L11.500. Some changes helped but anyway there were 6 stations that could not be measured because of the strong electromagnetic noise. The numerous power lines and the cables of the area generate local 3-D effects on the sounding curves, but the repeatability of the results is good. However, most suitable for monitoring purposes are the sites without strong 3-D effects. Comparison of results 2004-2007 shows small differences at some sounding sites. (orig.)

Biosphere analysis - a complementary assessment of dose conversion factors for the Olkiluoto site

International Nuclear Information System (INIS)

Kylloenen, J.; Keto, V.

2010-04-01

The Olkiluoto site is currently the primary candidate for the final disposal site for spent nuclear fuel from the Olkiluoto and Loviisa NPPs. Safety analysis calculations must be performed to verify the compliance with the long-term safety requirements. The behaviour and distribution of radionuclides in the biosphere is of high importance in these calculations. The aim of this study was to perform a complementary assessment of dose conversion factors for the Olkiluoto site. Posiva has performed extensive analysis on the different ecosystems. In this work the biosphere analysis model of Fortum Nuclear Services (FNS) is used to give an independent estimate of biosphere dose conversion factors for the Olkiluoto site. The following nuclides are analysed: Cl-36, Ni-59, Se-79, Mo-93, Nb-94, Sn-126, I-129 and Cs-135. The FNS model is an equilibrium compartment model in which a steady annual release of 1 Bq of each radionuclide is distributed in different scenarios. The scenarios are the well scenario, which models a small agricultural ecosystem, the lake scenario which models a larger ecosystem with both agriculture and lake use, and sea and transition scenario, which models the behaviour of the radionuclides in marine environments. The scenarios are described and the transfer equations written for the lake scenario. The parameter values are taken from the FNS biosphere database, which has been used in the Finnish L/ILW waste repository safety analyses since mid 1990's. The results of the FNS analysis are compared to those presented in Posiva working report 2000-20 (POSIVA-WR-00-20). The results are of the same order of magnitude for all nuclides except I-129. Since the Posiva and FNS models were independently constructed, the results can be considered as convincing, and the compliance of the results give confidence to the modelling results. (orig.)

Safety assessment of Olkiluoto NPP units 1 and 2. Decision of the Radiation and Nuclear Safety Authority regarding the periodic safety review of the Olkiluoto NPP

International Nuclear Information System (INIS)

2010-02-01

the principle of continuous improvement of safety provided in section 7 a of the Nuclear Energy Act.The safety of the plant will be further improved during the current operating licence period. Based on the periodic safety review, TVO has submitted to STUK action plans for the observed points requiring improvement. STUK included also some additional requirements in the decision relating to the periodic safety review. Action plans and additional requirements were for example related to diversification of the safety related systems, development of the lifecycle management of electronic and I and C equipment qualified for demanding conditions and ensuring the competence of personnel. As a summary of the review of the issues and documentation pertaining to the periodic safety review and the continuous oversight results, STUK notes that the safety of the Olkiluoto nuclear power plant units 1 and 2 is sufficient and the licensee utilises the necessary arrangements to continue the safe operation of the plants. (orig.)

Mise-a-la masse survey 2012-2013 in Olkiluoto and modelling of the data

International Nuclear Information System (INIS)

Ahokas, T.; Paananen, M.; Paulamaeki, S.; Korhonen, K.; Tiensuu, K.

2014-07-01

This report describes the Mise-a-la-masse (MAM) survey carried out in the Olkiluoto area in 2012 - 2013 and the modelling of the data. The aim of the survey was to find out the continuation of some electrically conductive zones intersected by drillholes drilled in the eastern part of the Olkiluoto island. In the modelling of the data both theoretical calculations and manual modelling were used to get more reliability to the modelling results. Also all the geological information of the known brittle fault zones was taken into account in the modelling. The modelling results will be used in the updates of the geological and hydrogeological models of the Olkiluoto area. Many of the electrically conductive zones modelled from the surveyed data coincide with the brittle deformation zones presented in the present geological model. The results showed also possibilities to join some modelled brittle zones together. According to the modelling results many brittle zones, especially the brittle and hydraulically conductive zone BFZ019C/HZ19C, has a quite complex structure. Many brittle zones also seem to have galvanic connections between each other. (orig.)

Electromagnetic Sampo soundings at Olkiluoto in 2007

International Nuclear Information System (INIS)

Korhonen, K.; Lehtimaeki, J.

2007-11-01

The Geological Survey of Finland (GTK) carried out a Sampo Gefinex 400S frequency domain electromagnetic (EM) survey in the central part of the eastern Olkiluoto island. The survey comprised a total of 408 soundings; 134 of these were measurements of EM noise. The goal of the survey was to supplement previously performed soundings. The measurements of EM noise were used to analyse the influence of power lines on the soundings. A statistically significant correlation was found between EM noise and the distance between the receiver and the high-voltage power line located northeast of the research area. The high-voltage power line exerted a considerable influence on the soundings. Numerical modelling was used to evaluate the effect of a dipping layer on the interpretation of Sampo soundings, which is based on the 1-D layered earth model. The results indicate that Sampo interpretation is robust even in the case of a dipping layer, assuming that the dip of the layer is not steep, and both the transmitter and receiver are located above the layer. The interpretations of the soundings indicate three conducting layers. There appear to be two layers of significant conductivity above the depth of 600 m. These layers may be indications of sulphide and/or graphite rich layers. Furthermore, a deeper conducting layer below the depth of 600 m was also indicated by the interpretations. This layer may indicate deep saline groundwater. (orig.)

Monitoring the bedrock stability in Olkiluoto. Summary of campaign based GPS measurements in 1996-2011

International Nuclear Information System (INIS)

Nyberg, S.; Kallio, U.; Haekli, P.; Jokela, J.; Koivula, H.; Saaranen, V.; Rouhiainen, P.

2013-12-01

The Finnish Geodetic Institute has monitored crustal deformations in Olkiluoto since mid-1990s. This is a final report of campaign based GPS measurements carried out in 1996-2011. The aim of the research has been monitoring the bedrock stability in the Olkiluoto area. The research were started in 1995, when a local GPS network of ten pillars, called inner network, was established on Olkiluoto Island. The research area was expanded in 2003- 2005 with four new pillars (outer network) established at 5-10 km distances from the inner network. One of the pillar points is the Olkiluoto permanent GPS station. Regular biannual measurement campaigns have been carried out on other pillar points

Core drilling of deep borehole OL-KR34 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-07-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 100.07 m deep borehole with a diameter of 75.7 mm at Olkiluoto in April 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR34. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of all measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 37m{sup 3} and the measured volume of the returning water was about 18m{sup 3} in borehole OL-KR34. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OLKR34 deviates 0.84 m right and 0.15 m up at the borehole depth of 99 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 142 MPa, the

Core drilling of deep borehole OL-KR36 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Niinimaeki, R.; Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-07-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 205.17 m deep borehole with a diameter of 75.7 mm at Olkiluoto in May 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR36. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling measurements. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 117 m{sup 3} and the measured volume of the returning water was about 51m{sup 3} in borehole OL-KR36. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR36 deviates 10.34 m left and 7.11 m up at the borehole depth of 204 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 126

Core drilling of deep borehole OL-KR35 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-07-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 100.87 m deep borehole with a diameter of 75.7 mm at Olkiluoto in May 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR35. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of all measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 53 m{sup 3} and the measured volume of the returning water was about 25 m{sup 3} in borehole OL-KR35. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR35 deviates 0.49 m right and 0.30 m up at the borehole depth of 99 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 90 MPa, the

Core drilling of deep borehole OL-KR32 at Olkiluoto in Eurajoki 2004

International Nuclear Information System (INIS)

Rautio, T.

2005-01-01

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, the ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled a 191.81 m deep borehole with a diameter of 75.7 mm at Olkiluoto in November 2004. This borehole was aimed to get additional information of the quality and the location of the fractured zones R20A and R20B and the fractured zones near rock surface noticed in investigation trench TK8. The identification number of the borehole is OL-KR32. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 93 m 3 and the measured volume of the returning water was about 6 m 3 in borehole OL-KR32. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR32 deviates 4.42 m right and 4.66 m up at the borehole depth of 189 m. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is about 130 MPa, the average Young's modulus is 47 GPa and the average Poisson

Feasibility study and technical proposal for seismic monitoring of tunnel boring machine in Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Saari, J.; Lakio, A. (AF-Consult Ltd, Vantaa (Finland))

2009-01-15

In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. The possibility to excavate an illegal access to the ONKALO, have been concerned when the safeguards are discussed. Therefore all recorded explosions in the Olkiluoto area and in the ONKALO are located. If a concentration of explosions is observed, the origin of that is found out. Also a concept of hidden illegal explosions, detonated at the same time as the real excavation blasts, has been examined. According to the experience gained in Olkiluoto, it can be concluded that, as long the seismic network is in operation and the results are analysed by a skilled person, it is practically impossible to do illegal excavation by blasts. In this report a possibility of seismic monitoring of illegal excavation done by tunnel boring machine (TBM) has been investigated. Characteristics of the seismic signal generated by the raise boring machine are described. According to this study, it can be concluded that the generated seismic signal can be detected and the source of the signal can be located. However, this task calls for different kind of monitoring system than that, which is currently used for monitoring microearthquakes and explosions. The presented technical proposal for seismic monitoring of TBM in Olkiluoto is capable to detect and locate TBM coming outside the ONKALO area about two months before it would reach the ONKALO. (orig.)

Feasibility study and technical proposal for seismic monitoring of tunnel boring machine in Olkiluoto

International Nuclear Information System (INIS)

Saari, J.; Lakio, A.

2009-01-01

In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. The possibility to excavate an illegal access to the ONKALO, have been concerned when the safeguards are discussed. Therefore all recorded explosions in the Olkiluoto area and in the ONKALO are located. If a concentration of explosions is observed, the origin of that is found out. Also a concept of hidden illegal explosions, detonated at the same time as the real excavation blasts, has been examined. According to the experience gained in Olkiluoto, it can be concluded that, as long the seismic network is in operation and the results are analysed by a skilled person, it is practically impossible to do illegal excavation by blasts. In this report a possibility of seismic monitoring of illegal excavation done by tunnel boring machine (TBM) has been investigated. Characteristics of the seismic signal generated by the raise boring machine are described. According to this study, it can be concluded that the generated seismic signal can be detected and the source of the signal can be located. However, this task calls for different kind of monitoring system than that, which is currently used for monitoring microearthquakes and explosions. The presented technical proposal for seismic monitoring of TBM in Olkiluoto is capable to detect and locate TBM coming outside the ONKALO area about two months before it would reach the ONKALO. (orig.)

The analysis of the bedrock deformation in Olkiluoto using precise levelling measurements

International Nuclear Information System (INIS)

Saaranen, V.; Rouhiainen, P.; Suurmaeki, H.

2014-01-01

In order to research vertical bedrock deformations in the Olkiluoto area, Posiva Oy and the Finnish Geodetic Institute began monitoring with precise levelling in 2003. At the moment, the measuring plan includes a loop between the monitoring GPS stations around the island, a levelling line from the island to the mainland, levelling loops to ONKALO, the final disposal site, and VLJ, the low and intermediate level waste repository there. The levelling to the mainland has been performed every fourth year and the levelling of the GPS stations every second year. The micro loops (ONKALO and VLJ) have been measured annually. In this report, we use three-step method to research a vertical deformation of the Olkiluoto area. Firstly, the linear deformation rate in the area has been determined by the least squares adjustment of the levelling data. It varies from -0.2 mm/yr to +0.2 mm/yr. Secondly, local deformations have been analysed by comparing the height differences for different years. In this comparison a starting value for the yearly adjustment has been corrected for land uplift. Using this method the elevation changes are relative to the whole network. For a fixed benchmark, we correct its yearly deformation. Thirdly, the fault lines have been analysed by comparing the elevation changes between the successive benchmarks from one observation epoch to another. The results show that ONKALO and Lapijoki are in the subsidence area of the network, and VLJ has small uplift rate. On the island some deformations exist, but elevation difference from 2003 to 2011 is less than one millimetre at every benchmarks. The measurements in the Lapijoki-Olkiluoto line in 2003, 2007 and 2011 show that linear elevation change between the mainland and Olkiluoto island is a little since 2003. The elevation differences, from Olkiluoto to Lapijoki, measured in 2003 and 2011 differ less than one millimetre each other, but the 2007 observation differs three millimetres from the other measurements

Means of achieving high load factors at Olkiluoto 1 and 2

International Nuclear Information System (INIS)

Patrakka, E.

2001-01-01

Teollisuuden Voima Oy operates two BWR units Olkiluoto 1 and 2 that have achieved load factors typically higher than 90%. The operating experiences gained in the 1990s is summarised and the factors contributing to the high capacity factors are addressed. These include the general objectives for operation and maintenance, plant modernisation programme, maintenance principles, and outage policy and experiences. Finally, the international evaluations performed at Olkiluoto are mentioned. (author)

Comparable investigation of the molecular size distribution and the amount of humic substances isolated from ONKALO, Olkiluoto, 2010

International Nuclear Information System (INIS)

Vilhunen, S.; Manninen, P.

2010-11-01

The humic substances at groundwater from Onkalo, Olkiluoto were studied in order to determine the molecular size distribution and the amount of humic substances. Humic substances were isolated from the water sample using DAX-8 resin and eluted with 0.1 M NaOH. The molecular size distribution was defined using high performance size exclusion chromatography (HPSEC) and ultraviolet (UV) or reflactive index (RI) detector. Two calibration standard sets (poly(styrene sulfonate) sodium salt (PSS) or polyethylene glycol (PEG) standards) with distinct structures as well as two eluents (0.05 M NaNO3 or 0.01 M Na-acetate) were studied and the results were compared with the previous ones. The calibration standards and eluents were found to have major effect on the measured parameters. The amount of humic substances was determined using total organic carbon (TOC) measurements. (orig.)

Dissolution rate of alpha-doped UO2 in natural groundwater

International Nuclear Information System (INIS)

Ollila, Kaija; Myllykylä, Emmi; Tanhua-Tyrkkö, Merja; Lavonen, Tiina

2013-01-01

The objective of this work is to determine whether the presence of trace elements in natural groundwaters affects the dissolution rate of uranium dioxide in the presence of alpha radiation that causes radiolysis of water. The study is a part of the project Reducing Uncertainty in Performance Prediction (REDUPP) under the Seventh Framework Programme of the European Atomic Energy Community (EURATOM). The project aims to reduce uncertainties related to the extrapolation of the results of laboratory experiments to the conditions expected under geologic disposal. Thus far, synthetic groundwater has been normally used in the experiments. The synthetic groundwaters used do not contain all of the chemical elements that occur in natural groundwaters. Three natural groundwaters were chosen for the dissolution experiments with 0%, 5%, and 10% 233 U-doped UO 2 samples. These include a brackish groundwater, a saline groundwater and a low ionic strength groundwater. At the time of writing this paper, the dissolution experiments have been finished in the first groundwater, which was a moderately saline, brackish groundwater. The groundwater samples for the experiments were taken from a borehole in the Olkiluoto site in Finland. The measurements for dissolution rates were conducted under reducing conditions established using metallic iron in solution and an argon atmosphere in the glove box. The isotope dilution method was used to decrease uncertainties due to precipitation and sorption effects. The resulting dissolution rates in OL-KR6 natural groundwater were generally somewhat higher than the rates measured previously in synthetic groundwaters under similar redox conditions. No clear effect of alpha radiolysis could be seen for tests with lower SA/V, while those for higher SA/V indicated that the dissolution rate was higher for the 10% 233 U-doped UO 2 , suggesting the effect of alpha radiolysis under these conditions

Local seismic network at the Olkiluoto site. Annual report 2002-2004

Energy Technology Data Exchange (ETDEWEB)

Saari, J. [Enprima Oy, Vantaa (Finland)

2005-09-15

In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. In the beginning, the network consisted of six seismic stations. Later, in June 2004, the seismic network was expanded with two new seismic stations. At that time started the excavation of the underground characterisation facility (the ONKALO) and the basic operation procedure was changed more suitable for the demands of the new situation. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during the years 2002 - 2004. Also the changes in the structure and the operation procedure of the network are described. The network has operated nearly continuously. The longest interruption occurred 16.-17.6.2004, when two new seismic stations were installed in the network and the operation procedure was changed. Altogether 757 events have been located in the Olkiluoto area. The magnitudes of the observed events range from ML = -3.5 to ML = 1.2. All of them are explosions or other artificial events. So far, none of the 757 observed events can be classified as microearthquakes. Five of the events have characteristics that make the origin of the recorded signal uncertain. They are quite unlikely microearthquakes, but they are not typical examples of artificial seismic signals either. When the experience and the data set of the Olkiluoto microearthquakes increase the identification of events will be more definite. Evidence of activity that would has influence on the safety of the ONKALO, have not found. (orig.)

Local seismic network at the Olkiluoto site. Annual report 2002-2004

International Nuclear Information System (INIS)

Saari, J.

2005-09-01

In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. In the beginning, the network consisted of six seismic stations. Later, in June 2004, the seismic network was expanded with two new seismic stations. At that time started the excavation of the underground characterisation facility (the ONKALO) and the basic operation procedure was changed more suitable for the demands of the new situation. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during the years 2002 - 2004. Also the changes in the structure and the operation procedure of the network are described. The network has operated nearly continuously. The longest interruption occurred 16.-17.6.2004, when two new seismic stations were installed in the network and the operation procedure was changed. Altogether 757 events have been located in the Olkiluoto area. The magnitudes of the observed events range from ML = -3.5 to ML = 1.2. All of them are explosions or other artificial events. So far, none of the 757 observed events can be classified as microearthquakes. Five of the events have characteristics that make the origin of the recorded signal uncertain. They are quite unlikely microearthquakes, but they are not typical examples of artificial seismic signals either. When the experience and the data set of the Olkiluoto microearthquakes increase the identification of events will be more definite. Evidence of activity that would has influence on the safety of the ONKALO, have not found. (orig.)

Core drilling of deep borehole OL-KR3B at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-10-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 530.60 m deep borehole with a diameter of 75.7 mm at Olkiluoto in summer 2005. This borehole was aimed to get additional information of the quality of bedrock in the area, where a new shaft with a diameter of 3 m is planned to be located. The identification number of the borehole is OL-KR38. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 473m{sup 3} and the measured volume of the returning water was about 38m{sup 3} in borehole OL-KR38. The deviation of the borehole was measured with the deviation measuring instruments EMS and Devitool Peewee. The results of the EMS measurements indicate that borehole OL-KR38 deviates 1.02 m south and 0.58 m west from the target point at the borehole depth of 525 m. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is about 106

Permanent vegetation quadrats on Olkiluoto island. Establishment and results from the first inventory

Energy Technology Data Exchange (ETDEWEB)

Huhta, A.P.; Korpela, L. [Finnish Forest Research Institute, Helsinki (Finland)

2006-05-15

This report describes in detail the vegetation quadrats established inside the permanent, follow-up sample plots (Forest Extensive High-level monitoring plots, FEH) on Olkiluoto Island. During summer 2005 a total of 94 sample plots (a 30 m{sup 2}), each containing eight quadrats (a 1m{sup 2}), were investigated. The total number of sampled quadrats was 752. Seventy of the 94 plots represent coniferous stands: 57 Norway spruce-dominated and 13 Scots pine-dominated stands. Ten of the plots represent deciduous, birch-dominated (Betula spp.) stands, 7 plots common alder-dominated (Alnus glutinosa) stands, and seven plots are mires. The majority of the coniferous tree stands were growing on sites representing various succession stages of the Myrtillus, Vaccinium-Myrtillus and Deschampsia-Myrtillus forest site types. The pine-dominated stands growing on exposed bedrock clearly differed from the other coniferous stands: the vegetation was characterised by the Cladina, Calluna-Cladina and Empetrum-Vaccinium vitis-idaea/Vaccinium Myrtillus forest site types. The deciduous stands were characterized by tall grasses, especially Calamagrostis epigejos, C. purpurea and Deschampsia flexuosa. The vegetation of the deciduous stands dominated by common alder represented grove-like sites and seashore groves. Typical species for mires included Calamagrostis purpurea, Calla palustris, Equisetum sylvaticum, and especially white mosses (Sphagnum spp.). A total of 184 vascular plant species were found growing within the quadrats. Due to the high number of quadrats in these forests, the spruce stands had the highest total number of species, but the birch and alder-dominated forests had the highest average number of species per quadrat. This basic inventory of the permanent vegetation quadrats on Olkiluoto Island provides a sound starting point for future vegetation surveys. Guidelines for future inventories and supplementary sampling are given in the discussion part of this report. (orig.)

Permanent vegetation quadrats on Olkiluoto island. Establishment and results from the first inventory

International Nuclear Information System (INIS)

Huhta, A.P.; Korpela, L.

2006-05-01

This report describes in detail the vegetation quadrats established inside the permanent, follow-up sample plots (Forest Extensive High-level monitoring plots, FEH) on Olkiluoto Island. During summer 2005 a total of 94 sample plots (a 30 m 2 ), each containing eight quadrats (a 1m 2 ), were investigated. The total number of sampled quadrats was 752. Seventy of the 94 plots represent coniferous stands: 57 Norway spruce-dominated and 13 Scots pine-dominated stands. Ten of the plots represent deciduous, birch-dominated (Betula spp.) stands, 7 plots common alder-dominated (Alnus glutinosa) stands, and seven plots are mires. The majority of the coniferous tree stands were growing on sites representing various succession stages of the Myrtillus, Vaccinium-Myrtillus and Deschampsia-Myrtillus forest site types. The pine-dominated stands growing on exposed bedrock clearly differed from the other coniferous stands: the vegetation was characterised by the Cladina, Calluna-Cladina and Empetrum-Vaccinium vitis-idaea/Vaccinium Myrtillus forest site types. The deciduous stands were characterized by tall grasses, especially Calamagrostis epigejos, C. purpurea and Deschampsia flexuosa. The vegetation of the deciduous stands dominated by common alder represented grove-like sites and seashore groves. Typical species for mires included Calamagrostis purpurea, Calla palustris, Equisetum sylvaticum, and especially white mosses (Sphagnum spp.). A total of 184 vascular plant species were found growing within the quadrats. Due to the high number of quadrats in these forests, the spruce stands had the highest total number of species, but the birch and alder-dominated forests had the highest average number of species per quadrat. This basic inventory of the permanent vegetation quadrats on Olkiluoto Island provides a sound starting point for future vegetation surveys. Guidelines for future inventories and supplementary sampling are given in the discussion part of this report. (orig.)

Results of monitoring at Olkiluoto in 2009. Hydrology

International Nuclear Information System (INIS)

Vaittinen, T.; Ahokas, H.; Klockars, J.; Nummela, J.; Pentti, E.; Penttinen, T.; Tammisto, E.; Karvonen, T.; Lindgren, S.

2010-08-01

The impact of the ONKALO construction is monitored by measuring and observing numerous different parameters of hydrology, geochemistry, environment, rock mechanics and foreign materials. The Hydrological Monitoring Programme consists of the following parameters: groundwater level, hydraulic head, flow conditions in open boreholes, cross drillhole flow, hydraulic conductivity, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff), infiltration, ground frost, leakages in tunnels, water balance in the tunnel system and in Korvensuo Reservoir. This Report focuses on hydrogeological parameters. Other parameters, like precipitation, ground frost etc. will be reported in the Environment Report. Mainly the monitoring has been carried out according to plan. This Report presents the results for the year 2009. A significant change in the Monitoring Programme was performed while most of the open drillholes were packed-off before excavation of the ONKALO access tunnel through the hydrogeological HZ20 zones began in Jun 2008. Prior to packing-off, open drillholes connected the main hydrogeological features, HZ19 and HZ20 systems, to each other. Due to packing-off open drillholes, number of flow logging and hydraulic testing monitoring measurements has considerably decreased. The observed changes in groundwater level in shallow observation tubes in the overburden and in shallow drillholes in the bedrock are not necessarily caused by the construction of ONKALO. However, weak indications of decrease in groundwater level have been observed. The effects on head deeper in the bedrock have been both shortterm and long-term and in 2009 these were mostly connected to drilling of grouting holes of the shafts trough the HZ20 zones. In other drillholes except packed-off sections connected to the HZ20 system, long-term changes i.e. decrease in pressure heads near ONKALO have remained on the same order of magnitude, c 1 m, as the year before

Results of monitoring at Olkiluoto in 2008. Hydrology

International Nuclear Information System (INIS)

Vaittinen, T.; Ahokas, H.; Klockars, J.; Nummela, J.; Penttinen, T.; Tammisto, E.; Karvonen, T.

2009-08-01

The impact of the ONKALO construction is monitored by measuring and observing numerous different parameters of hydrology, geochemistry, environment, rock mechanics and foreign materials. The Hydrological Monitoring Programme consists of the following parameters: groundwater level, hydraulic head, flow conditions in open boreholes, cross drillhole flow, hydraulic conductivity, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff), infiltration, ground frost, leakages in tunnels, water balance in the tunnel system and in Korvensuo Reservoir. This Report focuses on hydrogeological parameters. Other parameters, like precipitation, ground frost etc. will be reported in the Environment Report. Mainly the monitoring has been carried out according to plan. The previous Monitoring Report contained the results until the end of 2007, and this Report presents the results for the year 2008. A significant change in the Monitoring Programme was performed while most of the open drillholes were packed-off before excavation of the ONKALO access tunnel through the hydrogeological HZ20 zones began in Jun 2008. Prior to packing-off, open drillholes connected the main hydrogeological features, HZ19 and HZ20 systems, to each other. Due to packing-off open drillholes, number of flow logging and hydraulic testing monitoring measurements has considerably decreased. According to the observations carried out in shallow observation tubes in the overburden and in shallow drillholes in the bedrock, the construction of ONKALO has not caused any certain changes in groundwater level. However, weak indications of decrease in groundwater level have been observed. The effects on head deeper in the bedrock have been both short-term and long-term and in 2008 these were mostly connected to excavation of the tunnel trough the HZ20 zones. In most cases, short-term changes have been caused by temporary leakages due to the probe holes and grouting holes

Results of monitoring at Olkiluoto in 2010. Hydrology

Energy Technology Data Exchange (ETDEWEB)

Vaittinen, T.; Ahokas, H.; Klockars, J.; Nummela, J.; Pentti, E.; Penttinen, T.; Poellaenen, J. [Poeyry Finland Oy, Espoo (Finland); Karvonen, T. [WaterHope, Helsinki (Finland); Lindgren, S.

2012-03-15

The impact of the construction of ONKALO is monitored by measuring and observing numerous different parameters related to hydrology, geochemistry, environment, rock mechanics and foreign materials. The Hydrological Monitoring Programme consists of the following parameters: groundwater level, hydraulic head, flow conditions in open boreholes, cross drillhole flow, hydraulic conductivity, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff), infiltration, ground frost, leakages in tunnels, and water balance in the tunnel system and in Korvensuo Reservoir. This Report focuses on hydrogeological parameters. Other parameters, like precipitation, ground frost etc. will be reported in the Monitoring Report of Environment. Monitoring has primarily been carried out according to plan. This Report presents the results for the year 2010. A significant change took place in the Monitoring Programme when most of the open drillholes were packed-off before the excavation of the ONKALO access tunnel through the hydrogeological HZ20 zones began in June 2008. Prior to packing-off, open drillholes connected the main hydrogeological features, the HZ19 and HZ20 systems, to each other. Due to the packing-off of open drillholes, the number of flow logging and hydraulic testing (HTU) measurements has decreased considerably. The mapping of water leakages and moisture conditions in tunnel walls and roof has been continued. Some changes have been observed in the pattern of moisture content. The changes have probably been caused by shotcreting, postgrouting and possibly also by seasonal effects. The changes have so far not been analysed. The changes observed in the groundwater level in shallow observation tubes in the overburden and in shallow drillholes in the bedrock are not necessarily caused by the construction of ONKALO. However, weak indications of a decrease in groundwater level have been observed. Effects on the head deeper in the

Environmental Radioactivity Data of Olkiluoto in 1984-2001

International Nuclear Information System (INIS)

Ikonen, A.T.K.

2003-04-01

In this report, data of the environmental radiation surveillance programme of the Olkiluoto nuclear power plant is published in a collected format for further reference. The data reported consists of analysis results of selected environmental media and indicator organisms representing human food web, and it covers a period of 1984-2001. In addition to sampling and analysis results, also a concise description of data acquisition methods - when still traceable - and handling is provided as well as locations of sampling sites. (orig.)

Safety assessment of spent fuel disposal in Haestholmen, Kivetty, Olkiluoto and Romuvaara - TILA-99

Energy Technology Data Exchange (ETDEWEB)

Vieno, T.; Nordman, H. [VTT Energy (Finland)

1999-03-01

The spent fuel from the Finnish nuclear power plants is planned to be disposed of in copper-iron canisters emplaced in a KBS-3 type repository constructed at a depth of about 500 metres at one of the four candidate sites investigated. The disposal concept aims at long-term isolation of the spent fuel assemblies from the biosphere and even from the geosphere. The evaluation of the normal evolution of the disposal system accords with the conclusions of the previous Finnish, Swedish and Canadian safety assessments of similar disposal concepts. Subject to the influence of the expected, normal evolution of the repository, initially intact copper-iron canisters will most likely preserve their integrity for more than one million years at any of the candidate sites. Consequently, the best-estimate assessment is that there never will be any significant releases of radionuclides from the repository into the geosphere. Consequences of potential canister failures have been evaluated using conservative assumptions, models and data. The results show that at any of the sites a large number of canisters could be assumed to be initially defective or to `disappear` simultaneously after some time without that the proposed constraints for release rates into the biosphere or dose rates were exceeded. In most cases this conclusion is valid for all canisters failing simultaneously, even if rather pessimistic flow and transport data is used. In the sensitivity and `what if` analyses where very high flow rates of saline groundwater are assumed, highest release and dose rates are caused by weakly-sorbing cations Sr-90 and Ra-226. The most important differences between the sites are related to the coastal location and brackish/saline groundwater of Haestholmen and Olkiluoto, and on the other hand to the inland location and fresh groundwater of Kivetty and Romuvaara. Because of the ongoing postglacial land uplift at the coast of the Baltic Sea, Olkiluoto and Haestholmen, too, may become

Safety assessment of spent fuel disposal in Haestholmen, Kivetty, Olkiluoto and Romuvaara - TILA-99

International Nuclear Information System (INIS)

Vieno, T.; Nordman, H.

1999-03-01

The spent fuel from the Finnish nuclear power plants is planned to be disposed of in copper-iron canisters emplaced in a KBS-3 type repository constructed at a depth of about 500 metres at one of the four candidate sites investigated. The disposal concept aims at long-term isolation of the spent fuel assemblies from the biosphere and even from the geosphere. The evaluation of the normal evolution of the disposal system accords with the conclusions of the previous Finnish, Swedish and Canadian safety assessments of similar disposal concepts. Subject to the influence of the expected, normal evolution of the repository, initially intact copper-iron canisters will most likely preserve their integrity for more than one million years at any of the candidate sites. Consequently, the best-estimate assessment is that there never will be any significant releases of radionuclides from the repository into the geosphere. Consequences of potential canister failures have been evaluated using conservative assumptions, models and data. The results show that at any of the sites a large number of canisters could be assumed to be initially defective or to 'disappear' simultaneously after some time without that the proposed constraints for release rates into the biosphere or dose rates were exceeded. In most cases this conclusion is valid for all canisters failing simultaneously, even if rather pessimistic flow and transport data is used. In the sensitivity and 'what if' analyses where very high flow rates of saline groundwater are assumed, highest release and dose rates are caused by weakly-sorbing cations Sr-90 and Ra-226. The most important differences between the sites are related to the coastal location and brackish/saline groundwater of Haestholmen and Olkiluoto, and on the other hand to the inland location and fresh groundwater of Kivetty and Romuvaara. Because of the ongoing postglacial land uplift at the coast of the Baltic Sea, Olkiluoto and Haestholmen, too, may become

Core drilling of deep drillhole OL-KR56 at Olkiluoto in Eurajoki 2011 - 2012

Energy Technology Data Exchange (ETDEWEB)

Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

2012-07-15

As a part of the confirming site investigations at Olkiluoto, Suomen Malmi Oy (Smoy) core drilled a 1201.65 m deep drillhole with a diameter of 75.7 mm at Olkiluoto in October 2011 - January 2012. The identification number of the drillhole is OL-KR56. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling water were recorded. The drill rig was computer controlled and the computer recorded drilling parameters during drilling. The objective of the measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volume of the used drilling, washing and flushing water was 1628 m{sup 3}. The measured volume of the returning water in the drillhole was 1142 m{sup 3}. The deviation of the drillhole was measured with the deviation measuring instruments Reflex EMS and Reflex Gyro. The main rock types are veined and diatexitic gneisses, pegmatitic granite and mica gneiss. The average fracture frequency is 2.4 pcs/m and the average RQD value is 96.2 %. Fifty fractured zones were penetrated by the drillhole. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength was 120.0 MPa, the average Young's Modulus was 38.3 GPa and the average Poisson's ratio was 0.22. (orig.)

Core drilling of deep borehole OL-KR32 at Olkiluoto in Eurajoki 2004

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-01-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, the ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled a 191.81 m deep borehole with a diameter of 75.7 mm at Olkiluoto in November 2004. This borehole was aimed to get additional information of the quality and the location of the fractured zones R20A and R20B and the fractured zones near rock surface noticed in investigation trench TK8. The identification number of the borehole is OL-KR32. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 93 m{sup 3} and the measured volume of the returning water was about 6 m{sup 3} in borehole OL-KR32. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR32 deviates 4.42 m right and 4.66 m up at the borehole depth of 189 m. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is about 130 MPa, the average Young's modulus is 47 GPa and

Core drilling of drillholes ONK-PVA9 and ONK-PVA10 in ONKALO at Olkiluoto 2011

Energy Technology Data Exchange (ETDEWEB)

Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

2011-10-15

Suomen Malmi Oy (Smoy) core drilled two drillholes for groundwater monitoring stations in ONKALO at Eurajoki, Olkiluoto in 2011. The groundwater monitoring stations are used for monitoring changes in groundwater conditions. The drillhole ONK-PVA9 was drilled in March 2011 and the drillhole ONK-PVA10 in June 2011. The lengths of the drillholes are 15.95 and 20.10 m respectively. The drillholes are 75.7 mm by diameter. The drillhole ONK-PVA9 was drilled in a niche of the access tunnel at chainage 4366 and the ONK-PVA10 in the access tunnel wall at chainage 3851. The hydraulic DE 130 drilling rig was used. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. The drillholes were measured with EMS deviation survey tool. In addition to drilling the drillcores were logged and reported by geologist. Geological logging included the following parameters: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillholes are veined gneiss and pegmatitic granite. The average fracture frequencies in drill cores are 2.9 pcs/m (ONK-PVA9) and 2.3 pcs/m (ONK-PVA10) and the average RQD values 81.6 % and 96.2 % respectively. (orig.)

Estimations of durability of fracture mineral buffers in the Olkiluoto bedrock

International Nuclear Information System (INIS)

Luukkonen, A.

2006-12-01

This study attempts to make scenarios for the geochemical effects that the underground excavations in the Olkiluoto bedrock have on naturally occurring fracture mineral buffers. The excavations of underground research facilities and final repository galleries probably cause steep hydraulic gradients in some bedrock fractures. These gradients likely draw surficial waters within the fracture network and activate weathering processes deeper in rock fractures than in the natural undisturbed conditions. The present studies concentrate on the meteoric infiltration in a single rock fracture, and on the selected set of minerals believed to be significant buffers against pH/redox variations in groundwater. The modelling considers the possibility that the infiltrating meteoric water is soil water rich in dissolved inorganic carbon. Calcite, pyrite, quartz, amorphous silica, cordierite, hornblende, albite, K-feldspar, kaolinite, and illite are taken into account as reacting minerals. Simulations are done by varying the flow rate of water from 1 L/h to 100 L/h. The effects of mineral reactions onto porosity and permeability values are monitored as well. In the present study, however, the changes in physical properties of the fracture channel do not affect the flow rate of water. Furthermore, calculations also describe how cation exchange affects the studied fracture channel system. The simulations coupling the hydraulic flow and water-rock interaction were done with TOUGHREACT V1.0 code and with the EQ3/6-database implemented in the code. In part, the simulations were evaluation of the code capabilities, and verification of results to earlier PHREEQC-2 simulation results. The calculation results confirm the assumption that principal buffer against pH changes is calcite. All silicate reactions, with considered reactive surface areas, are by comparison of marginal importance. The only redox buffer in the calculations is pyrite, and consequently significant amounts of oxygen runs

Climate scenarios for Olkiluoto on a time-scale of 120,000 years

Energy Technology Data Exchange (ETDEWEB)

Pimenoff, N.; Venaelaeinen, A.; Jaervinen, H. [Finnish Meteorological Institute, Helsinki (Finland)

2011-12-15

Posiva Oy is planning to dispose of spent nuclear fuel in a repository, to be constructed at a depth of 400 m in the crystalline bedrock at Olkiluoto, Finland. Planning the storage requires careful consideration of many aspects, including an assessment of long-term repository safety. For estimating possible climate states at Olkiluoto on a time-scale of 120,000 years, we analyze climate simulations of an Earth System Model of Intermediate Complexity (CLIMBER-2) coupled with an ice sheet model (SICOPOLIS). The simulations into the future clearly show that the onset of the next glaciation is strongly dependent on the Earth's orbital variations and the atmospheric CO{sub 2} concentration. It is evident that due to global warming, the climate of the next centuries will be warmer and wetter than at present. Most likely, due to global warming and low variations in the Earth's orbit around the sun, the present interglacial will last for at least the next 30,000 years. Further, the future simulations showed that the insolation minima on the Northern Hemisphere 50,000-60,000 and 90,000-100,000 years after the present hold a potential for the onset of the next glaciation. Hence, on a time-scale of 120,000 years, one must take into account climate periods lasting several thousand years having the following features: an interglacial climate, a periglacial climate, a climate with an ice sheet margin near Olkiluoto, a glacial climate with an ice sheet covering Olkiluoto, and a climate with Olkiluoto being depressed below sea level after glaciation due to isostatic depression. Due to the uncertainties related to the evolution of the future climate, it is recommended the simulations into the far future to be used only qualitatively. Quantitative information about glacial climate is achieved from the reconstructions and simulations of the past climate. (orig.)

Climate scenarios for Olkiluoto on a time-scale of 120,000 years

International Nuclear Information System (INIS)

Pimenoff, N.; Venaelaeinen, A.; Jaervinen, H.

2011-12-01

Posiva Oy is planning to dispose of spent nuclear fuel in a repository, to be constructed at a depth of 400 m in the crystalline bedrock at Olkiluoto, Finland. Planning the storage requires careful consideration of many aspects, including an assessment of long-term repository safety. For estimating possible climate states at Olkiluoto on a time-scale of 120,000 years, we analyze climate simulations of an Earth System Model of Intermediate Complexity (CLIMBER-2) coupled with an ice sheet model (SICOPOLIS). The simulations into the future clearly show that the onset of the next glaciation is strongly dependent on the Earth's orbital variations and the atmospheric CO 2 concentration. It is evident that due to global warming, the climate of the next centuries will be warmer and wetter than at present. Most likely, due to global warming and low variations in the Earth's orbit around the sun, the present interglacial will last for at least the next 30,000 years. Further, the future simulations showed that the insolation minima on the Northern Hemisphere 50,000-60,000 and 90,000-100,000 years after the present hold a potential for the onset of the next glaciation. Hence, on a time-scale of 120,000 years, one must take into account climate periods lasting several thousand years having the following features: an interglacial climate, a periglacial climate, a climate with an ice sheet margin near Olkiluoto, a glacial climate with an ice sheet covering Olkiluoto, and a climate with Olkiluoto being depressed below sea level after glaciation due to isostatic depression. Due to the uncertainties related to the evolution of the future climate, it is recommended the simulations into the far future to be used only qualitatively. Quantitative information about glacial climate is achieved from the reconstructions and simulations of the past climate. (orig.)

Climate scenarios for Olkiluoto on a time-scale of 100,000 years

International Nuclear Information System (INIS)

Pimenoff, N.; Venaelaeinen, A.; Jaervinen, H.

2011-01-01

Posiva Oy is planning to dispose of spent nuclear fuel in a repository, to be constructed at a depth of 400 m in the crystalline bedrock at Olkiluoto, Finland. Planning the storage requires careful consideration of many aspects, including an assessment of long-term repository safety. For estimating possible climate states at Olkiluoto on a time-scale of 100,000 years, we analyze climate simulations of an Earth System Model of Intermediate Complexity (CLIMBER-2) coupled with an ice sheet model (SICOPOLIS). The simulations into the future clearly show that the onset of the next glaciation is strongly dependent on the Earth's orbital variations and the atmospheric CO 2 concentration. It is evident that due to global warming, the climate of the next centuries will be warmer and wetter than at present. Most likely, due to global warming and low variations in the Earth's orbit around the sun, the present interglacial will last for at least the next 30,000 years. Further, the future simulations showed that the insolation minima on the Northern Hemisphere 50,000-60,000 and 90,000-100,000 years after the present hold a potential for the onset of the next glaciation. Hence, on a time-scale of 100,000 years, one must take into account climate periods lasting several thousand years having the following features: an interglacial climate, a periglacial climate, a climate with an ice sheet margin near Olkiluoto, a glacial climate with an ice sheet covering Olkiluoto, and a climate with Olkiluoto being depressed below sea level after glaciation due to isostatic depression. Due to the uncertainties related to the evolution of the future climate, it is recommended the simulations into the far future to be used only qualitatively. Quantitative information about glacial climate is achieved from the reconstructions and simulations of the past climate. (orig.)

Core drilling of short drillholes at Olkiluoto in Eurajoki 2006

International Nuclear Information System (INIS)

Rautio, T.

2007-05-01

Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled six short drillholes with a diameter of 75.7 mm at Olkiluoto in July - August 2006. The identification numbers of the drillholes are OL-PP51 - OL-PP56. The deviation of the drillholes was measured with the deviation measuring instruments Reflex EMS. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. The volume of the drilling water was recorded. Sodium fluorescein was used as a label agent in the drilling water. The total volume of the used drilling and flushing water were 37 m 3 . (orig.)

A system of nomenclature for rocks in Olkiluoto

International Nuclear Information System (INIS)

Mattila, J.

2006-06-01

Due to international interest in the Finnish deep repository project at Olkiluoto (SW Finland) and the need for collaboration between scientists involved in site investigations for the disposal of spent nuclear fuel in other countries, a well-documented system of rock nomenclature is required, based on existing classification schemes and international recommendations. The BGS (British Geological Survey) rock classification scheme is the most comprehensive rock classification scheme and the basic principles behind it are utilised for the system of nomenclature for rocks in Olkiluoto. The BGS classification system is based on the use of descriptive names and a clear hierarchy, making it possible to classify rocks at different levels depending on the specific goals of the study, the level of available information, and the expertise of the user. Each rock type is assigned a root name, which is based on structural and textural characteristics or modal compositions of the rock and the root names are refined with qualifier terms as prefixes. Qualifier terms refer to the structure or modal composition of the rock. The bedrock at the Olkiluoto site consists of metamorphic and igneous rocks. The metamorphic rocks consist of migmatitic gneisses and (non-migmatitic) gneisses, which are further divided according to their structural characteristics and modal compositions, the former into stromatic, veined, diatexitic gneisses, the latter into mica, quartz, mafic and TGG gneisses. Igneous rocks consist of pegmatitic granites, K-feldspar porphyry and diabases. (orig.)

Mise-a-la-masse surveys at Olkiluoto, 2006

International Nuclear Information System (INIS)

Tarvainen, A.-M.

2007-02-01

Suomen Malmi Oy conducted Mise-a-la-masse surveys at Olkiluoto site in Eurajoki during November and December 2006. The surveys are a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included field work, data processing and technical raporting. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. Data is delivered digitally in xyz-format. (orig.)

Core drilling of deep borehole OL-KR39 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Niinimaeki, R. [Suomen Malmi Oy, Espoo (Finland)

2005-11-15

Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 502.97 m and 45.11 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in August- October 2005. The identification numbers of the boreholes are OL-KR39 and OL-KR39B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 415m{sup 3} and 25 m{sup 3} and the measured volumes of the returning water were 175 m{sup 3} and 7 m{sup 3} in boreholes OLKR39 and OL-KR39B, respectively. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 110 MPa, the average Young's Modulus is 49 GP a and the average Poisson' s ratio is 0.25. The main rock types are migmatitic mica gneiss and granite. Filled fracture is the most common

Core drilling of deep borehole OL-KR37 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Niinimaeki, R. [Suomen Malmi Oy, Espoo (Finland)

2005-11-15

Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 350.00 m and 45.10 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in June- August 2005. The identification numbers of the boreholes are OL-KR37 and OL-KR37B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 273 m{sup 3} and 21m{sup 3} and the measured volumes of the returning water were 221m{sup 3} and 16m{sup 3} in boreholes OL-KR37 and OL-KR37B, respectively. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 106 MPa, the average Young's modulus is 40 GPa and the average Poisson's ratio is 0.20. The main rock types are migmatitic mica gneiss, granite and tonalite. Filled

Core drilling of deep borehole OL-KR39 at Olkiluoto in Eurajoki 2005

International Nuclear Information System (INIS)

Niinimaeki, R.

2005-11-01

Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 502.97 m and 45.11 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in August- October 2005. The identification numbers of the boreholes are OL-KR39 and OL-KR39B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 415m 3 and 25 m 3 and the measured volumes of the returning water were 175 m 3 and 7 m 3 in boreholes OLKR39 and OL-KR39B, respectively. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 110 MPa, the average Young's Modulus is 49 GP a and the average Poisson' s ratio is 0.25. The main rock types are migmatitic mica gneiss and granite. Filled fracture is the most common fracture type. The average fracture

Core drilling of deep borehole OL-KR46 at Olkiluoto in Eurajoki 2007

International Nuclear Information System (INIS)

Toropainen, V.

2007-09-01

Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 600.10 m and 45.16 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in May - June 2007. The identification numbers of the boreholes are OL-KR46 and OL-KR46B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning water, and the volume of drilling water were recorded. The drill rig was computer controlled and during drilling the computer recorded drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 466 m 3 and 20 m 3 in boreholes OL-KR46 and OL-KR46B, respectively. Measured volumes of the returning water were 407 m 3 in borehole OL-KR46 and 12 m 3 in borehole OL-KR46B. The deviation of the boreholes was measured with the deviation measuring instruments EMS and Maxibor. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is 116.5 MPa, the average Young's Modulus is 31.5 GPa and the average Poisson's ratio is 0.20. The main rock types are veined gneiss, tonalitic-granodioritic-granitic gneiss and pegmatite

Core drilling of deep drillhole OL-KR45 at Olkiluoto in Eurajoki 2007

International Nuclear Information System (INIS)

Toropainen, V.

2007-11-01

Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 1023.30 m and 44.75 m deep drillholes with a diameter of 75.7 mm at Olkiluoto in June - September 2007. The identification numbers of the drillholes are OL-KR45 and OL-KR45B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling waters were recorded. The drill rig was computer controlled and during drilling the computer recorded drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and washing water were 1186 m 3 and 19 m 3 in drillholes OL-KR45 and OL-KR45B, respectively. Measured volumes of the returning water were 962 m 3 in drillhole OL-KR45 and 15 m 3 in drillhole OL-KR45B. The deviation of the drillholes was measured with the deviation measuring instruments EMS and Maxibor II. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is 126.2 MPa, the average Young's Modulus is 42.5 GPa and the average Poisson's ratio is 0.21. The main rock types are veined and diatexitic gneisses, pegmatitic granite and tonalitic

Compilation and analysis of hydrogeological responses to field activities in Olkiluoto

International Nuclear Information System (INIS)

Vaittinen, T.; Nummela, J.; Ahokas, H.

2008-01-01

Groundwater flow characteristics provide essential input for the construction and safety assessment of a disposal facility for spent nuclear fuel. On the Olkiluoto site flow connections have been studied in deep drillholes by means of long-term pumping tests, varying interference tests, and by interpreting the measured hydraulic heads. This report focuses on the assessment of measured hydraulic heads. Hydraulic heads have been measured both in open and in packed-off drillholes since 1991. The interpretation of the hydraulic connections is based on observed changes in hydraulic head distribution caused by certain investigation activities on the site. Field activities may increase the head, e.g. drilling, or more typically decrease the head, e.g. flush pumping after drilling, difference flow logging with pumping, and groundwater sampling. All the measured head observations have been gathered to binary files and a code has been developed to enable inquiries of head values for selected field activities. The main improvement has been the possibility for easy comparison of head observations in several drillholes. This report contains a short description of the pumping and the over-pressure tests, hydraulic head observations in packed-off drillholes until the end of 2005, and an interpretation of the selected representative cases. The presented cases highlight both the advantages and the difficulties related to the interpretation of the available hydraulic head data. Based on the head observations in packed-off drillholes, sub-horizontal hydraulic zones seem to form a layered system and indicate weak sub-vertical connections. The results of the pumping tests carried out between 1991 and 1998 are the most valuable, because the drillholes were mostly packed-off during the tests. Later, observations have suffered from open drillholes, which spread the head changes to all intersected hydrogeological zones. Due to the open drillholes, the existence of sub-vertical hydraulic

Olkiluoto 1 and 2 - Plant efficiency improvement and lifetime extension-project (PELE) implemented during outages 2010 and 2011

Energy Technology Data Exchange (ETDEWEB)

Kosonen, M.; Hakola, M. [Teollisuuden Voima Oyj, F- 27160 Eurajoki (Finland)

2012-07-01

Teollisuuden Voima Oyj (TVO) is a non-listed public company founded in 1969 to produce electricity for its stakeholders. TVO is the operator of the Olkiluoto nuclear power plant. TVO follows the principle of continuous improvement in the operation and maintenance of the Olkiluoto plant units. The PELE project (Plant Efficiency Improvement and Lifetime Extension), mainly completed during the annual outages in 2010 and 2011, and forms one part of the systematic development of Olkiluoto units. TVO maintains a long-term development program that aims at systematically modernizing the plant unit systems and equipment based on the latest technology. According to the program, the Olkiluoto 1 and Olkiluoto 2 plant units are constantly renovated with the intention of keeping them safe and reliable, The aim of the modernization projects is to improve the safety, reliability, and performance of the plant units. PELE project at Olkiluoto 1 was done in 2010 and at Olkiluoto 2 in 2011. The outage length of Olkiluoto 1 was 26 d 12 h 4 min and Olkiluoto 2 outage length was 28 d 23 h 46 min. (Normal service-outage is about 14 days including refueling and refueling-outage length is about seven days. See figure 1) The PELE project consisted of several single projects collected into one for coordinated project management. Some of the main projects were as follows: - Low pressure turbines: rotor, stator vane, casing and turbine instrumentation replacement. - Replacement of Condenser Cooling Water (later called seawater pumps) pumps - Replacement of inner isolation valves on the main steam lines. - Generator and the generator cooling system replacement. - Low voltage switchgear replacement. This project will continue during future outages. PELE was a success. 100 TVO employees and 1500 subcontractor employees participated in the project. The execution of the PELE projects went extremely well during the outages. The replacement of the low pressure turbines and seawater pumps improved the

Olkiluoto 1 and 2 - Plant efficiency improvement and lifetime extension-project (PELE) implemented during outages 2010 and 2011

International Nuclear Information System (INIS)

Kosonen, M.; Hakola, M.

2012-01-01

Teollisuuden Voima Oyj (TVO) is a non-listed public company founded in 1969 to produce electricity for its stakeholders. TVO is the operator of the Olkiluoto nuclear power plant. TVO follows the principle of continuous improvement in the operation and maintenance of the Olkiluoto plant units. The PELE project (Plant Efficiency Improvement and Lifetime Extension), mainly completed during the annual outages in 2010 and 2011, and forms one part of the systematic development of Olkiluoto units. TVO maintains a long-term development program that aims at systematically modernizing the plant unit systems and equipment based on the latest technology. According to the program, the Olkiluoto 1 and Olkiluoto 2 plant units are constantly renovated with the intention of keeping them safe and reliable, The aim of the modernization projects is to improve the safety, reliability, and performance of the plant units. PELE project at Olkiluoto 1 was done in 2010 and at Olkiluoto 2 in 2011. The outage length of Olkiluoto 1 was 26 d 12 h 4 min and Olkiluoto 2 outage length was 28 d 23 h 46 min. (Normal service-outage is about 14 days including refueling and refueling-outage length is about seven days. See figure 1) The PELE project consisted of several single projects collected into one for coordinated project management. Some of the main projects were as follows: - Low pressure turbines: rotor, stator vane, casing and turbine instrumentation replacement. - Replacement of Condenser Cooling Water (later called seawater pumps) pumps - Replacement of inner isolation valves on the main steam lines. - Generator and the generator cooling system replacement. - Low voltage switchgear replacement. This project will continue during future outages. PELE was a success. 100 TVO employees and 1500 subcontractor employees participated in the project. The execution of the PELE projects went extremely well during the outages. The replacement of the low pressure turbines and seawater pumps improved the

KBS-3H layout adaptation 2007 for the Olkiluoto site

International Nuclear Information System (INIS)

Johansson, Erik; Hagros, Annika; Autio, Jorma; Kirkkomaeki, Timo

2008-05-01

As part of the KBS-3H design an Olkiluoto-specific layout of a KBS-3H repository has been produced based on the latest Olkiluoto data and the bedrock model. One of the main goals of this work was to support the evaluation of the feasibility of the one layer KBS-3H concept and to compare the layouts based on the KBS-3H and KBS-3V disposal concepts. The layout presented in this work can be considered only preliminary and involves a number of uncertainties. The percentage of unusable host rock was assumed to be 25% in this work but can change due to the further design of the different components of the KBS-3H disposal system and further development of the host rock criteria. The layout is also significantly affected by the layout-determining fracture zones. In this work 11 major (highly transmissive) fracture zones interpreted to intersect the -420 m level were considered deterministically. The KBS-3H layout requires a larger area than the KBS-3V repository and takes up most of the available area between the major fracture zones HZ20 and HZ21. This is mainly due to the long drift sections occupied by the compartment plugs (30 m) and the bentonite blocks in the blank zones (10 m), which reduces the usability of the host rock and results in larger canister spacings than in the KBS-3V concept, where the positioning of the deposition holes is very flexible and narrow zones with a moderate transmissivity usually have only a minor effect on the locations of the canisters. According to the results, there is enough bedrock in the current investigation area at central Olkiluoto for KBS-3H layout in one layer. However the layout takes up nearly all of the potential bedrock resource and therefore the result is quite sensitive to possible changes in the design bases

Core drilling of deep drillhole OL-KR50 at Olkiluoto in Eurajoki 2008

International Nuclear Information System (INIS)

Toropainen, V.

2009-02-01

As a part of the confirming site investigations at Olkiluoto, Suomen Malmi Oy (Smoy) core drilled 939.33 m and 45.44 m deep drillholes with a diameter of 75.7 mm at Olkiluoto in September - November 2008. The identification numbers of the drillholes are OL-KR50 and OL-KR50B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling water were recorded. The drill rig was computer controlled and the computer recorded drilling parameters during drilling. The objective of the measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and washing water were 1135 m 3 and 20 m 3 in the drillholes OL-KR50 and OL-KR50B, respectively. The measured volume of the returning water in the drillhole OL-KR50 was 954 m 3 . The deviation of the drillholes was measured with the deviation measuring instruments EMS and Maxibor II. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength was 129.7 MPa, the average Young's Modulus was 45.8 GPa and the average Poisson's ratio was 0.15. The main rock types were veined and diatexitic gneisses, pegmatitic granite and tonaliticgranodioritic-granitic gneiss. The average fracture frequency is 2.0 pcs/m in drillhole OL KR50 and 3.6 pcs/m in the drillhole OL-KR50B. The average RQD values are 96.1 % and 94.3 %, respectively. 39 fractured zones were penetrated by drillhole OL-KR50 and four by drillhole OL-KR50B. (orig.)

Updated and integrated modelling of the 1995 - 2008 Mise-a-la-masse survey data in Olkiluoto

International Nuclear Information System (INIS)

Ahokas, T.; Paananen, M.

2010-01-01

Posiva Oy prepares for disposal of spent nuclear fuel into bedrock focusing in Olkiluoto, Eurajoki. This is in accordance of the Decision-in-Principle of the State Council in 2000, and ratification by the Parliament in 2001. The ONKALO underground characterization premises have been constructed since 2004. Posiva Oy is aiming for submitting the construction licence application in 2012. To support the compilation of the safety case and repository and ONKALO design and construction, an integrated Olkiluoto site Description including geological, rock mechanics, hydrogeological and hydrogeochemical models will be depicted. Mise-a-la-masse (MAM) surveys have been carried out in the Olkiluoto area since 1995 to follow electric conductors from drillhole to drillhole, from drillhole to the ground surface and also between the ONKALO access tunnel and drillholes or the ground surface. The data and some visualisation of the data have been presented as part of reporting of the 1995 and 2008 surveys. The work presented in this paper includes modelling of all the measured data and combining single conductors modelled from different surveys to conductive zones. The results from this work will be used in updating the geological and hydrogeological models of the Olkiluoto site area. Several electrically conductive zones were modelled from the examined data, many of them coincide with the known brittle deformation zones but also indications of many so far unknown zones were detected. During the modelling Comsol Multiphysics software for calculating theoretical potential field anomalies of different models was tested. The test calculations showed that this software is useful in confirming the modelling results, especially in complicated cases. (orig.)

Concentration ratios to great cormorant (Phalacrocorax carbo) at Olkiluoto repository site

Energy Technology Data Exchange (ETDEWEB)

Kangasniemi, Ville; Ikonen, Ari T.K. [Environmental Research and Assessment EnviroCase, Ltd., Hallituskatu 1 D 4, 28100 Pori (Finland); Haavisto, Fiia [FM Meri and Erae Oy, Seijaistentie 133a, 21230 Lemu (Finland); Salmi, Juhani A. [Finnish Game and Fisheries Research Institute, Itaeinen Pitkaekatu 3, 20520 Turku (Finland)

2014-07-01

Olkiluoto Island on the western coast of Finland has been selected as a repository site for spent nuclear fuel disposal. The great cormorant was a common species in the Finnish coastal area and possibly also a resource for human uses before the decline of the cormorant population in the 18. century. During the last decade, the great cormorant has become again a relevant part of food web in the Bothnian Sea coastal area. Due to the regulatory requirements, the biosphere assessment demonstrating the long-term safety of the repository is developed into more and more site specific. As the adequate literature data on common waterfowl is sparse or in some cases lacking, samples of adult cormorants, eggs and guano together with water and fish samples were collected from the Olkiluoto coastal area. This contribution will present concentration ratios of stable element based on these samples with focus on the elements of a high relevance to the biosphere assessment of the Olkiluoto spent fuel repository together with discussion on the role of food (fish) versus the application of the water-to-bird concentration ratio. (authors)

Results of monitoring at Olkiluoto in 2012 - hydrology and hydrogeology

Energy Technology Data Exchange (ETDEWEB)

Vaittinen, T.; Ahokas, H.; Komulainen, J.; Nummela, J.; Pentti, E.; Tammisto, E.; Turku, J. [Poeyry Finland Oy, Espoo (Finland); Karvonen, T. [WaterHope, Helsinki (Finland); Aro, S.

2013-10-15

The impact of the construction of ONKALO is monitored by measuring and observing numerous different parameters related to hydrology, geochemistry, environment, rock mechanics and foreign materials. The Hydrological Monitoring Programme consists of the following parameters: groundwater level, hydraulic head, flow conditions in open drillholes, transverse flow, hydraulic conductivity, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff), infiltration, ground frost, leakages in tunnels, and water balance in the tunnel system and in Korvensuo Reservoir. This Report focuses on hydrogeological parameters. Other parameters, like precipitation, ground frost etc. will be reported in the Monitoring Report of Environment. Updated monitoring program was introduced in the beginning of 2012. The updated program will be used for the period before repository operation. Only minor changes were implemented. Monitoring has been carried out according to plan. This Report presents the results for the year 2012. The access tunnel was excavated from chainage 4913 m to chainage 4987 m in 2012. In addition, demonstration tunnel 2 from chainage 65 m to 101 m and some technical facilities were excavated. Total inflow into ONKALO down to chainage 4580 m including shaft ONK-KU2 down to level -427m was 36 l/min at the end of 2012. The mapping of water leakages and moisture conditions on the tunnel walls and the ceiling has been continued. The general pattern of leakages has remained similar during the construction of ONKALO. Most significant differences are caused by seasonal effects like condensation of warm ventilation air on tunnel walls and ceiling. The changes observed in the groundwater level in shallow observation tubes in the overburden and in shallow drillholes in the bedrock are not necessarily caused by the construction of ONKALO. However, weak indications of a local decrease in groundwater level have been observed. Effects on the

Core drilling of deep borehole OL-KR33 at Olkiluoto in Eurajoki 2004

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-01-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, the ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 311.02 m and 45.53 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in November-December 2004. These boreholes were aimed to get additional information of the quality of bedrock and the quality and the location of the fractured zones R2, RH9 and R72. The identification numbers of the boreholes are OL-KR33 and OL-KR33B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volumes of the used drilling water were about 195m{sup 3} and 14m{sup 3} and the measured volumes of the returning water were about 100 m{sup 3} and 9 m{sup 3} in boreholes OL-KR33 and OL-KR33B, respectively. The deviations of the boreholes were measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR33 deviates 15.97 m right and 31.04 m up at the borehole depth of 309 m. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive

Ageing study of protection automation components of Olkiluoto nuclear power plant

International Nuclear Information System (INIS)

Simola, K.; Haenninen, S.

1993-07-01

A study on ageing of reactor protection system of the Olkiluoto nuclear power plant is described. The objective of the study was to present an ageing analysis approach and apply in to the automation chains of reactor protection system of the Olkiluoto nuclear power plant. The study includes the measuring instrumentation, the protection logics, and the control electronics of some pumps and valves. The analysis is based on the information collected on the structure of the system, environmental conditions and maintenance practices of components, and operating experience. Based on this information, the possible ageing effects of equipment and their safety significance are evaluated. (orig.). (15 refs., 16 figs., 12 tabs.)

Hydrogeological structure model of the Olkiluoto Site. Update in 2010

International Nuclear Information System (INIS)

Vaittinen, T.; Ahokas, H.; Nummela, J.; Paulamaeki, S.

2011-09-01

As part of the programme for the final disposal of spent nuclear fuel, a hydrogeological structure model containing the hydraulically significant zones on Olkiluoto Island has been compiled. The structure model describes the deterministic site scale zones that dominate the groundwater flow. The main objective of the study is to provide the geometry and the hydrogeological properties related to the groundwater flow for the zones and the sparsely fractured bedrock to be used in the numerical modelling of groundwater flow and geochemical transport and thereby in the safety assessment. Also, these zones should be taken into account in the repository layout and in the construction of the disposal facility and they have a long-term impact on the evolution of the site and the safety of the disposal repository. The previous hydrogeological model was compiled in 2008 and this updated version is based on data available at the end of May 2010. The updating was based on new hydrogeological observations and a systematic approach covering all drillholes to assess measured fracture transmissivities typical of the site-scale hydrogeological zones. New data consisted of head observations and interpreted pressure and flow responses caused by field activities. Essential background data for the modelling included the ductile deformation model and the site scale brittle deformation zones modelled in the geological model version 2.0. The GSM combine both geological and geophysical investigation data on the site. As a result of the modelling campaign, hydrogeological zones HZ001, HZ008, HZ19A, HZ19B, HZ19C, HZ20A, HZ20B, HZ21, HZ21B, HZ039, HZ099, OL-BFZ100, and HZ146 were included in the structure model. Compared with the previous model, zone HZ004 was replaced with zone HZ146 and zone HZ039 was introduced for the first time. Alternative zone HZ21B was included in the basic model. For the modelled zones, both the zone intersections, describing the fractures with dominating groundwater

Potential reference mires and lakes ecosystems for biosphere assessment of Olkiluoto site

International Nuclear Information System (INIS)

Haapanen, R.; Aro, L.; Kirkkala, T.; Paloheimo, A.; Koivunen, S.; Lahdenperae, A.-M.

2010-10-01

New lakes and mires will develop in the sea area now surrounding Olkiluoto Island due to the postglacial land uplift. The properties of these objects can be forecast using data from existing lakes and mires. There are, however, no such objects on the present Olkiluoto Island. This Working Report presents a project, initiated in 2007, where lakes and mires at different successional stages, suitable as reference objects for the future ones, were searched. The task included delineation of the study area, based on e.g. geological and climatological factors, and development of the selection criteria. As background, development history and properties of present lakes and mires in the study area are described in this report. For this and forthcoming projects, several GIS data sets were acquired. With help of these data, literature and environmental databases, 33 mires and 27 lakes were selected. These were considered to be the best available analogues for the future objects around Olkiluoto Island. The characteristics of these objects are presented briefly; more detailed information is found in the literature and databases. (orig.)

Local seismic network at the Olkiluoto site. Annual report for 2013

International Nuclear Information System (INIS)

Saari, J.; Malm, M.

2014-06-01

This report gives the results of microseismic monitoring during 2013. Excavation of the underground rock characterisation facility called ONKALO started in 2004. Before that, in February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto, where there are currently 17 seismic stations and 21 triaxial sensors. The network has operated continuously in 2013. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas, of which the larger one, the seismic semiregional area, includes the Olkiluoto island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. All the expected excavation induced events are assumed to occur inside the smaller target area, the seismic ONKALO block, which is a 2 km x 2 km x 2 km cube surrounding the ONKALO and includes 13 seismic stations. An additional task of monitoring is related to safeguarding of the construction of ONKALO. Upgrade and unification of the whole seismic network was done in August 2013. The upgrade included communication, data acquisition, server equipment in Olkiluoto, network configuration and software. The bedrock models and the ONKALO design model applied in the visualisation of the seismicity remained the same in 2013. The number of located events was much smaller than during previous years due to break in the excavation. Altogether 436 events have been located in the Olkiluoto area, in the reported time period. Nearly half of the observed explosions (237) in 2013 occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (137). The magnitudes of the explosions inside the semi-regional area range from M L = -1.6 to M L = 1.5 (M L = magnitude in local Richter's scale). One small induced earthquake (ML = -1.8) was detected on 9 May 2013

Local seismic network at the Olkiluoto site. Annual Report for 2007

International Nuclear Information System (INIS)

Saari, J.; Lakio, A.

2008-05-01

In February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto. Later, in June 2004, the seismic network was expanded with two new seismic stations. At that time started the excavation of the underground characterisation facility (the ONKALO) and the basic operation procedure was changed more suitable for the demands of the new situation. In the beginning of 2006, the target area of the seismic monitoring expanded to semiregional scale. Four new seismic stations started in the beginning of February 2006 and the focus of interpretation was expanded to an area, called the seismic semi-regional area. At the end of 2006, two new borehole geophones were installed in order to improve the sensitivity and the depth resolution of the measurements inside the ONKALO block. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during the year 2007. Also the changes in the structure and the operation procedure of the network are described. The true orientation of the borehole sensor OL-OS13 was calculated. The correct orientation of triaxial seismometer is essential when the fault plane solution of an earthquake is calculated. The other borehole sensor OL-OS14 was permanently disconnected in October 2007. The network has operated continuously in 2007. Altogether 2207 events have been located in the Olkiluoto area, in reported time period. Altogether 2207 events have been located in 2007. Most of them (1912) are explosions occurred inside the seismic semiregional area and especially inside the ONKALO block (1891 events). The magnitudes of the observed events inside the semi-regional area range from ML = -2.1 to ML = 1.5 (ML

Safety analysis of disposal of decommissioning waste from the Olkiluoto nuclear power plant - PURKU-93

International Nuclear Information System (INIS)

Vieno, T.; Meszaros, F.; Nordman, H.; Taivassalo, V.

1993-12-01

Decommissioning waste from the Olkiluoto nuclear power plant will be disposed of at the depth between 60 and 100 meters in the bedrock at the power plant site. The existing VLJ repository for low and medium level operating waste will be extended with three new silos for the decommissioning waste of the TVO I and II reactors and the spent fuel interim store at the Olkiluoto site. Besides dismantling waste also used fuel boxes, control rods and other activated metal components accumulated during the operation of the reactors will be disposed of in the repository. The safety analysis is based on the detailed decommissioning plan of the Olkiluoto power plants and the comprehensive safety analysis carried out for the Final Safety Analysis Report of the VLJ repository. (58 refs., 31 figs., 38 tabs.)

Raise Boring of the ventilation shaft in Olkiluoto, 17. - 23.5.2006. Preliminary analysis of seismic signal

Energy Technology Data Exchange (ETDEWEB)

Saari, J.; Lakio, A. [AaF-Enprima Oy, Vantaa (Finland)

2007-01-15

In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. The possibility to excavate an illegal access to the ONKALO, have been concerned when the safeguards are discussed. Therefore all recorded explosions in the Olkiluoto area and in the ONKALO are located. If a concentration of explosions is observed, the origin of that is found out. Also a concept of hidden illegal explosions, detonated at the same time as the real excavation blasts, has been examined. According to the experience gained in Olkiluoto, it can be concluded that, as long the seismic network is in operation and the results are analysed by a skilled person, it is practically impossible to do illegal excavation by blasts. In this report a possibility of seismic monitoring of illegal excavation done by tunnel boring machine has been investigated. Characteristics of the seismic signal generated by the raise boring machine are analysed. According to this study, it can be concluded that the generated seismic signal can be detected and the source of the signal can be located. However, this task calls for different kind of monitoring system than that, which is currently used for monitoring microearthquakes and explosions. (orig.)

Raise Boring of the ventilation shaft in Olkiluoto, 17. - 23.5.2006. Preliminary analysis of seismic signal

International Nuclear Information System (INIS)

Saari, J.; Lakio, A.

2007-01-01

In Olkiluoto, Posiva Oy has operated a local seismic network since February 2002. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. The possibility to excavate an illegal access to the ONKALO, have been concerned when the safeguards are discussed. Therefore all recorded explosions in the Olkiluoto area and in the ONKALO are located. If a concentration of explosions is observed, the origin of that is found out. Also a concept of hidden illegal explosions, detonated at the same time as the real excavation blasts, has been examined. According to the experience gained in Olkiluoto, it can be concluded that, as long the seismic network is in operation and the results are analysed by a skilled person, it is practically impossible to do illegal excavation by blasts. In this report a possibility of seismic monitoring of illegal excavation done by tunnel boring machine has been investigated. Characteristics of the seismic signal generated by the raise boring machine are analysed. According to this study, it can be concluded that the generated seismic signal can be detected and the source of the signal can be located. However, this task calls for different kind of monitoring system than that, which is currently used for monitoring microearthquakes and explosions. (orig.)

Core drilling of deep drillhole OL-KR57 at Olkiluoto in Eurajoki 2011-2012

International Nuclear Information System (INIS)

Toropainen, V.

2012-07-01

As a part of the confirming site investigations at Olkiluoto, Suomen Malmi Oy (Smoy) core drilled 401.71 m and 45.01 m deep drillholes, OL-KR57 and OL-KR57B, at Olkiluoto in September 2011 - January 2012. The diameter of the drillholes is 75.7 mm. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling water were recorded. The drill rig was computer controlled and the computer recorded drilling parameters during drilling. The objective of the measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling, flushing and washing water were 350 m3 and 30 m3 in the drillholes OL-KR57 and OL-KR57B, respectively. The measured volumes of the returning water in the drillholes were 328 m 3 and 16.8 m 3 , respectively. The deviations of the drillholes were measured with the deviation measuring instruments EMS and Gyro. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength was 123.9 MPa, the average Young's Modulus was 42.6 GPa and the average Poisson's ratio was 0.23. The main rock types are veined and diatexitic gneisses, mica gneiss and tonaliticgranodioritic- granitic gneiss. The average fracture frequency is 2.5 pcs/m in drillhole OL-KR57 and 3.3 pcs/m in the drillhole OL-KR57B. The average RQD values are 95.0 % and 93.0 %. Seven separate fractured zones were interpreted from OL-KR57 and three fractured zones from OL-KR57B. (orig.)

Core drilling of deep drillhole OL-KR57 at Olkiluoto in Eurajoki 2011-2012

Energy Technology Data Exchange (ETDEWEB)

Toropainen, V. [Suomen Malmi Oy, Espoo (Finland)

2012-07-15

As a part of the confirming site investigations at Olkiluoto, Suomen Malmi Oy (Smoy) core drilled 401.71 m and 45.01 m deep drillholes, OL-KR57 and OL-KR57B, at Olkiluoto in September 2011 - January 2012. The diameter of the drillholes is 75.7 mm. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling water were recorded. The drill rig was computer controlled and the computer recorded drilling parameters during drilling. The objective of the measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling, flushing and washing water were 350 m3 and 30 m3 in the drillholes OL-KR57 and OL-KR57B, respectively. The measured volumes of the returning water in the drillholes were 328 m{sup 3} and 16.8 m{sup 3}, respectively. The deviations of the drillholes were measured with the deviation measuring instruments EMS and Gyro. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength was 123.9 MPa, the average Young's Modulus was 42.6 GPa and the average Poisson's ratio was 0.23. The main rock types are veined and diatexitic gneisses, mica gneiss and tonaliticgranodioritic- granitic gneiss. The average fracture frequency is 2.5 pcs/m in drillhole OL-KR57 and 3.3 pcs/m in the drillhole OL-KR57B. The average RQD values are 95.0 % and 93.0 %. Seven separate fractured zones were interpreted from OL-KR57 and three fractured zones from OL-KR57B. (orig.)

Operation set for 2018 as regulator considers olkiluoto-3 licence application

Energy Technology Data Exchange (ETDEWEB)

Kraev, Kamen [NucNet, Brussels (Belgium)

2017-02-15

Finland has announced progress with its delayed nuclear project and has confirmed it will not be affected by anomalies discovered in some components manufactured for EPRs in France. The Olkiluoto-3 European Pressurised Reactor (EPR) nuclear plant under construction in Finland is on schedule to begin commercial operation in 2018 with the country's regulator preparing a safety assessment that will pave the way for fuel loading. Jouni Silvennoinen, senior vice-president for Olkiluoto-3 at Teollisuuden Voima Oyj (TVO), told NucNet that fuel loading at the EPR plant, which is nine years behind schedule, is expected in the spring of 2018. He said construction and licensing of the plant are progressing.

Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

Energy Technology Data Exchange (ETDEWEB)

Moenkkoenen, H. [WSP Finland Oy, Helsinki (Finland)

2012-04-15

In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

International Nuclear Information System (INIS)

Moenkkoenen, H.

2012-04-01

In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

Core drilling of deep borehole OL-KR43 at Olkiluoto in Eurajoki 2006

Energy Technology Data Exchange (ETDEWEB)

Niinimaeki, R. [Suomen Malmi Oy, Espoo (Finland)

2006-12-15

Posiva Oy submitted an application to the Finnish Government in May 1999 for the Decision in Principle to choose Olkiluoto in the municipality of Eurajoki as the site of the final disposal facility for spent nuclear fuel. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the decision in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 1000.26 m and 45.01 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in July - October 2006. The identification numbers of the boreholes are OL-KR43 and OL-KR43B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 1103 m{sup 3} and 16 m{sup 3} in boreholes OL-KR43 and OL-KR43B, respectively. Measured volumes of the returning water were 916m{sup 3} in borehole OL-KR43 and 13m{sup 3} in borehole OL-KR43B. The deviation of the boreholes was measured with the deviation measuring instruments EMS and Maxibor. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is about 131 MPa, the average Young's Modulus is 37 GPa and the average Poisson's ratio is 0.19. The main rock types are veined gneiss, diatexitic gneiss

Geophysical investigations in the Olkiluoto area, Finland

International Nuclear Information System (INIS)

Heikkinen, E.; Paananen, M.

1992-12-01

Investigations were carried out at the Olkiluoto site at Eurajoki using geological, geophysical, geohydrological and geochemical methods in 1987-1992 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

Optical imaging of borehole PR10 at Olkiluoto 2006

International Nuclear Information System (INIS)

Tarvainen, A.-M.

2007-03-01

Suomen Malmi Oy carried out optical imaging of borehole PR10 at Olkiluoto site in Eurajoki during December 2006. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and the data processing. This report describes the field operation, the equipment as well as the processing procedures and shows the obtained results and their quality. The raw and processed data are delivered digitally in WellCAD and PDF format. (orig.)

Comparison of site descriptive models for Olkiluoto, Finland and Forsmark, Sweden

Energy Technology Data Exchange (ETDEWEB)

Geier, J.; Bath, A.; Stephansson, O.; Luukkonen, A.

2012-08-15

The proposed high-level radioactive waste repository sites at Olkiluoto and Forsmark share broadly similar geologic histories and regional settings. Despite differences in lithology, rock strength and patterns of brittle deformation, the sites show similarities in terms of hydrogeochemistry and hydrogeology. These similarities reflect a dominating influence of saline and brackish water intrusion during inundation by the postglacial Littorina Sea and Baltic Sea, followed by exposure to meteoric waters following postglacial uplift and transition to a Baltic coastal setting. Both sites also contain deep bedrock saline groundwater, though this is more evident at Olkiluoto than at Forsmark. A comparative study of site descriptive models for the two sites identifies the following key differences that could potentially impact safety of a repository: (1) Redox controls, buffering and biogeochemistry at proposed repository depths; (2) Salinity gradients at and below proposed repository depths; (3) Methane concentrations at and below proposed repository depths; (4) Depths to which glacial water and Littorina water penetrated; (5) Cation hydrogeochemistry and water-rock reaction; (6) Pore water compositions in rock matrix; (7) Rock fabric, secondary minerals and alteration with respect to radionuclide retention; (8) Brittle deformation fabric differences on multiple scales that affect vertical hydraulic conductivity; (9) Differences in apparent frequency of encountering water-conducting networks at proposed repository depths; (10) Shallow bedrock hydraulic properties; (11) Unique intrusive or dissolution features; (12) Connectivity of site-scale models to regional-scale features; (13) Mesoproterozoic rocks in vicinity and possibilities for human-intrusion scenarios; (14) Rock stresses and bedrock strength and deformability at proposed repository depths; (15) Thermal anisotropy. These differences are all potentially significant to safety functions, but none are so severe that

Safety case for the disposal of spent nuclear fuel at Olkiluoto - Synthesis 2012

International Nuclear Information System (INIS)

2012-12-01

TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR 2012) and application for a construction licence for a spent nuclear fuel repository. Consistent with the Government Decisions-in- Principle, this foresees a repository developed in bedrock at the Olkiluoto site according to the KBS-3 method, designed to accept spent nuclear fuel from the lifetime operations of the Olkiluoto and Loviisa reactors. Synthesis 2012 presents a synthesis of Posiva Oy's Safety Case 'TURVA-2012' portfolio. It summarises the design basis for the repository at the Olkiluoto site, the assessment methodology and key results of performance and safety assessments. It brings together all the lines of argument for safety, evaluation of compliance with the regulatory requirements, and statement of confidence in long-term safety and Posiva's safety analyses. The TURVA-2012 safety case demonstrates that the proposed repository design provides a safe solution for the disposal of spent nuclear fuel, and that the performance and safety assessments are fully consistent with all the legal and regulatory requirements related to long-term safety as set out in Government Decree 736/2008 and in guidance from the nuclear regulator - the STUK. Moreover, Posiva considers that the level of confidence in the demonstration of safety is appropriate and sufficient to submit the construction licence application to the authorities. The assessment of long-term safety includes uncertainties, but these do not affect the basic conclusions on the long-term safety of the repository. (orig.)

Analysis of temperature data at the Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Sedighi, M.; Bennett, D.; Masum, S.; Thomas, H. [Cardiff Univ. (United Kingdom); Johansson, E. [Saanio and Riekkola Oy, Helsinki (Finland)

2014-03-15

As part of the rock mechanics monitoring programme 2012 at Olkiluoto, temperature data have been recorded. Temperature data have been measured, collected and monitored at the Olkiluoto site and in ONKALO in various locations, by different methods and in conjunction with other investigations carried out at the site. This report provides a detailed description of the investigation and analysis carried out on temperature datasets. This report aims to provide a better understanding of the in-situ temperature of the rock and soil at the site. Three categories of datasets have been analysed and studied from the Posiva thermal monitoring programme. These consist of: (i) data collected from the various drillholes during geophysical logging and Posiva Flow Log (PFL) measurements, (ii) measurements in the ONKALO ramp, the investigation niche located at elevation -140 m and a technical room located at 437 m below the surface, and (iii) surface temperature measurements from four weather stations and four measurement ditches. Time-series data obtained from the groundwater temperature measurements during the 'Posiva Flow Log' (PFL) tests in drillholes OL-KR1 to KR55 at different depths and years have been analysed. Temperature at a depth of 400 m was found to be in the range of 10 to 11 deg C. The geothermal gradient obtained from the PFL data without pumping was found to be approximately 1.4 deg C/100m with relatively uniform temporal and spatial patterns at the repository depth, i.e. at 400 m.The geothermal gradient obtained from the results of the PFL measurements and geophysical loggings indicate similar temperature values at the repository depths, i.e. 400 m. The characteristics of the time series data related to the ONKALO measurements, have been obtained through a series of Non-uniform Discrete Fourier Transform analysis Datasets related to the various chainages and investigation niche at ONKALO have been studied. The largest variation in the temperature

Analysis of temperature data at the Olkiluoto

International Nuclear Information System (INIS)

Sedighi, M.; Bennett, D.; Masum, S.; Thomas, H.; Johansson, E.

2014-03-01

As part of the rock mechanics monitoring programme 2012 at Olkiluoto, temperature data have been recorded. Temperature data have been measured, collected and monitored at the Olkiluoto site and in ONKALO in various locations, by different methods and in conjunction with other investigations carried out at the site. This report provides a detailed description of the investigation and analysis carried out on temperature datasets. This report aims to provide a better understanding of the in-situ temperature of the rock and soil at the site. Three categories of datasets have been analysed and studied from the Posiva thermal monitoring programme. These consist of: (i) data collected from the various drillholes during geophysical logging and Posiva Flow Log (PFL) measurements, (ii) measurements in the ONKALO ramp, the investigation niche located at elevation -140 m and a technical room located at 437 m below the surface, and (iii) surface temperature measurements from four weather stations and four measurement ditches. Time-series data obtained from the groundwater temperature measurements during the 'Posiva Flow Log' (PFL) tests in drillholes OL-KR1 to KR55 at different depths and years have been analysed. Temperature at a depth of 400 m was found to be in the range of 10 to 11 deg C. The geothermal gradient obtained from the PFL data without pumping was found to be approximately 1.4 deg C/100m with relatively uniform temporal and spatial patterns at the repository depth, i.e. at 400 m.The geothermal gradient obtained from the results of the PFL measurements and geophysical loggings indicate similar temperature values at the repository depths, i.e. 400 m. The characteristics of the time series data related to the ONKALO measurements, have been obtained through a series of Non-uniform Discrete Fourier Transform analysis Datasets related to the various chainages and investigation niche at ONKALO have been studied. The largest variation in the temperature amplitude of data

Challenges and Solutions for the Integration of Structural and Hydrogeological Understanding of Fracture Systems - Insights from the Olkiluoto Site, Finland

Science.gov (United States)

Hartley, L. J.; Aaltonen, I.; Baxter, S. J.; Cottrell, M.; Fox, A. L.; Hoek, J.; Koskinen, L.; Mattila, J.; Mosley, K.; Selroos, J. O.; Suikkanen, J.; Vanhanarkaus, O.; Williams, T. R. N.

2017-12-01

A field site at Olkiluoto in SW Finland has undergone extensive investigations as a location for a deep geological repository for spent nuclear fuel, which is expected to become operational in the early 2020s. Characterisation data comes from 58 deep cored drillholes, a wide variety of geophysical investigations, many outcrops, kilometres of underground mapping and testing in the ONKALO research facility, and groundwater pressure monitoring and sampling in both deep and shallow holes. A primary focus is on the properties of natural fractures and brittle fault zones in the low permeability crystalline rocks at Olkiluoto; an understanding of the flow and transport processes in these features are an essential part of assessing long-term safety of the repository. This presentation will illustrate how different types of source data and cross-disciplinary interpretations are integrated to develop conceptual and numerical models of the fracture system. A model of the brittle fault zones developed from geological and geophysical data provides the hydrostructural backbone controlling the most intense fracturing and dynamic conduits for fluids. Models of ductile deformation and lithology form a tectonic framework for the description of fracture heterogeneity in the background rock, revealing correlations between the intensity and orientation of fractures with geological and spatial properties. The sizes of brittle features are found to be best defined on two scales relating to individual fractures and zones. Inferred fracture-specific from flow logging are correlated with fracture geometric and mechanical properties along with in situ stress measurements to create a hydromechanical description of fracture hydraulic properties. The insights and understandings gained from these efforts help define a discrete fracture network (DFN) model for the Olkiluoto site, with hydrogeological characteristics consistent with monitoring data of hydraulic heads and their disturbances to

Comparable investigation of the molecular size distribution and the amount of humic substances isolated from ONKALO, Olkiluoto, 2011

International Nuclear Information System (INIS)

Luste, S.; Maekelae, J.; Manninen, P.

2012-06-01

The humic substances (HS) at groundwater from ONKALO, Olkiluoto were studied in order to determine the apparent molecular size distribution and the amount of humic substances. Humic substances were isolated from the water sample using DAX-8 resin and eluted with 0.1 M NaOH. The molecular size distribution was defined using high performance size exclusion chromatography (HPSEC) and ultraviolet (UV) and refractive index (RI) detector. In the SEC calibration (polystyrene sulfonate) sodium salts (PSS) were employed. Different eluents (NaNO 3 , Na-acetate and asetonitrile) with phosphate buffer and distinct ionic strengths were studied in order to optimize the determination method. The amount of humic substances was determined using total organic carbon (TOC) measurements. The results were compared with the previous ones in order to find out the variation of different methods (HPSEC) and to follow up the HS quantity (TOC). The method developed during the study is considered to be suitable for the HS molecular size distribution follow up, although the method development is suggested to be continued. (orig.)

Comparable investigation of the molecular size distribution and the amount of humic substances isolated from ONKALO, Olkiluoto, 2011

Energy Technology Data Exchange (ETDEWEB)

Luste, S.; Maekelae, J.; Manninen, P. [Ramboll Finland Oy, Espoo (Finland)

2012-06-15

The humic substances (HS) at groundwater from ONKALO, Olkiluoto were studied in order to determine the apparent molecular size distribution and the amount of humic substances. Humic substances were isolated from the water sample using DAX-8 resin and eluted with 0.1 M NaOH. The molecular size distribution was defined using high performance size exclusion chromatography (HPSEC) and ultraviolet (UV) and refractive index (RI) detector. In the SEC calibration (polystyrene sulfonate) sodium salts (PSS) were employed. Different eluents (NaNO{sub 3}, Na-acetate and asetonitrile) with phosphate buffer and distinct ionic strengths were studied in order to optimize the determination method. The amount of humic substances was determined using total organic carbon (TOC) measurements. The results were compared with the previous ones in order to find out the variation of different methods (HPSEC) and to follow up the HS quantity (TOC). The method developed during the study is considered to be suitable for the HS molecular size distribution follow up, although the method development is suggested to be continued. (orig.)

Microbially induced corrosion of carbon steel in deep groundwater environment

Directory of Open Access Journals (Sweden)

Pauliina eRajala

2015-07-01

Full Text Available The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland for periods of three and eight months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel.

Geological setting of the Olkiluoto investigation site, Eurajoki, SW Finland. Excursion guidebook

International Nuclear Information System (INIS)

Paulamaeki, S.

2009-08-01

Olkiluoto is an island of ca. 10 km 2 in area on the coast of the Botnian Bay and separated from the mainland by a narrow strait. The Olkiluoto nuclear power plant, with two reactors in operation and a third one under construction, and the underground repository for low and intermediate waste are located in the western part of the island. The repository for spent fuel will be constructed in the central part of the island at a depth of between 400 and 600 m. The suitability of Olkiluoto as a location for a spent fuel repository has been investigated over a period of 20 years by means of extensive ground- and air-based methods and shallow and deep drillings. In a regional context, Olkiluoto is located within a bedrock area, covering approximately 800 million years of geological history of the Precambrian Fennoscandian Shield. The oldest part of the bedrock consists of supracrustal, metasedimentary and metavolcanic rocks deformed and metamorphosed during the Palaeoproterozoic Svecofennian orogeny ca. 1900-1800 million years ago. They are mostly migmatised, high-grade metamorphic mica gneisses, containing cordierite, sillimanite or garnet porphyroblasts. Plutonic rocks consisting of trondhjemites, tonalites, granodiorites, coarse-grained granites and pegmatites intrude the supracrustal rocks. The Mesoproterozoic anorogenic Laitila rapakivi batholith, dated at 1583 ±3 Ma, is located in the central part of the region. The Eurajoki rapakivi stock, located 5 km east of Olkiluoto, is a satellite massif to the Laitila batholiths. After the rapakivi magmatism the geological evolution of the area continued with the deposition of the Satakunta sandstone. The upper parts of the sandstone were deposited ca. 1400-1300 Ma ago, but the development of the sedimentation basin (graben) may have begun already during the rifting period, ca. 1650 Ma ago, associated with the intrusion of the rapakivi magma. The sandstone and older rocks are cut by olivine diabase dykes and sills 1270

Game statistics for the island of Olkiluoto in 2009-2010

Energy Technology Data Exchange (ETDEWEB)

Nieminen, M. (Faunatica Oy, Espoo (Finland))

2010-10-15

The game statistics for the island of Olkiluoto were updated in the spring 2010, and compared with earlier studies. Population size estimates are based on interviews of local hunters, and on other material available. No elk nor deer inventories were made in the winter 2009-2010. The elk population is still slightly decreasing. The white-tailed deer population was made smaller by hunting. The changes in the roe deer population are not known accurately, but population size varies somewhat from year to year. The number of hunted small predators approximately doubled in the latest hunting season. Altogether 17 waterfowl were hunted in 2009 (none in the previous year). The populations of mountain hare and red squirrel are abundant. The brown hare population is still small, even though there was one brood in Olkiluoto in 2009. (orig.)

Game statistics for the island of Olkiluoto in 2009-2010

International Nuclear Information System (INIS)

Nieminen, M.

2010-10-01

The game statistics for the island of Olkiluoto were updated in the spring 2010, and compared with earlier studies. Population size estimates are based on interviews of local hunters, and on other material available. No elk nor deer inventories were made in the winter 2009-2010. The elk population is still slightly decreasing. The white-tailed deer population was made smaller by hunting. The changes in the roe deer population are not known accurately, but population size varies somewhat from year to year. The number of hunted small predators approximately doubled in the latest hunting season. Altogether 17 waterfowl were hunted in 2009 (none in the previous year). The populations of mountain hare and red squirrel are abundant. The brown hare population is still small, even though there was one brood in Olkiluoto in 2009. (orig.)

Local seismic network at the Olkiluoto site. Annual report for 2011

International Nuclear Information System (INIS)

Saari, J.; Malm, M.

2012-06-01

This report gives the results of microseismic monitoring during 2011. Excavation of the underground characterisation facility called ONKALO started in 2004. Before that, in February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto. After that the number of seismic stations has increased gradually. In 2011 Posiva's permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km x 2 km x 2 km cube surrounding ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the construction of ONKALO. The configuration of the seismic network as well as the software packages applied in data processing and analyses have remained during the previous year. The design model of ONKALO and the brittle fault zone model of the Olkiluoto of the seismic visualization package Jdi were upgraded in 2011. The network has operated nearly continuously. There was a 14 minutes and 30 second long operation failure in December 2011. That was the first network operation failure in five years. Altogether 1223 events have been located in the Olkiluoto area, in the reported time period. Most of them (1098) are explosions that occurred inside the seismic semiregional area and especially inside the seismic ONKALO block (1064 events). The magnitudes of the observed explosions inside the semi

Local seismic network at the Olkiluoto site. Annual report for 2011

Energy Technology Data Exchange (ETDEWEB)

Saari, J.; Malm, M. [AF-Consult Oy, Espoo (Finland)

2012-06-15

This report gives the results of microseismic monitoring during 2011. Excavation of the underground characterisation facility called ONKALO started in 2004. Before that, in February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto. After that the number of seismic stations has increased gradually. In 2011 Posiva's permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km x 2 km x 2 km cube surrounding ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the construction of ONKALO. The configuration of the seismic network as well as the software packages applied in data processing and analyses have remained during the previous year. The design model of ONKALO and the brittle fault zone model of the Olkiluoto of the seismic visualization package Jdi were upgraded in 2011. The network has operated nearly continuously. There was a 14 minutes and 30 second long operation failure in December 2011. That was the first network operation failure in five years. Altogether 1223 events have been located in the Olkiluoto area, in the reported time period. Most of them (1098) are explosions that occurred inside the seismic semiregional area and especially inside the seismic ONKALO block (1064 events). The magnitudes of the observed explosions inside the

Geological discrete-fracture network model (version 1) for the Olkiluoto site, Finland

International Nuclear Information System (INIS)

Fox, A.; Buoro, A.; Dahlbo, K.; Wiren, L.

2009-10-01

This report describes the methods, analyses, and conclusions of the modelling team in the production of a discrete-fracture network (DFN) model for the Olkiluoto Site in Finland. The geological DFN is a statistical model for stochastically simulating rock fractures and minor faults at a scale ranging from approximately 0.05 m to approximately 500 m; an upper scale limit is not expressly defined, but the DFN model explicitly excludes structures at deformation-zone scales (∼ 500 m) and larger. The DFN model is presented as a series of tables summarizing probability distributions for several parameters necessary for fracture modelling: fracture orientation, fracture size, fracture intensity, and associated spatial constraints. The geological DFN is built from data collected during site characterization (SC) activities at Olkiluoto, which is currently planned to function as a final deep geological repository for spent fuel and nuclear waste from the Finnish nuclear power program. Data used in the DFN analyses include fracture maps from surface outcrops and trenches (as of July 2007), geological and structural data from cored boreholes (as of July 2007), and fracture information collected during the construction of the main tunnels and shafts at the ONKALO laboratory (January 2008). The modelling results suggest that the rock volume at Olkiluoto surrounding the ONKALO tunnel can be separated into three distinct volumes (fracture domains): an upper block, an intermediate block, and a lower block. The three fracture domains are bounded horizontally and vertically by large deformation zones. Fracture properties, such as fracture orientation and relative orientation set intensity, vary between fracture domains. The rock volume at Olkiluoto is dominated by three distinct fracture sets: subhorizontally-dipping fractures striking north-northeast and dipping to the east, a subvertically-dipping fracture set striking roughly north-south, and a subverticallydipping fracture set

Environmental radioactivity data of Olkiluoto in 1977-1983 and 2002-2003

International Nuclear Information System (INIS)

Roiviainen, P.

2005-05-01

In this report, data of the environmental radiation surveillance programme of the Olkiluoto nuclear power plant is published in a collected format for further reference. The data reported consists of analysis results of selected environmental media and indicator organisms representing human food web, and it covers periods of 1977-1983 and 2002-2003. In addition to sampling and analysis results, also a concise description of data acquisition methods - when still traceable - and handling is provided as well as locations of sampling sites. (orig.)

Electrical model of Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Paananen, M.; Lehtonen, T.; Korhonen, K. (Geological Survey of Finland, Espoo (FI))

2007-05-15

The goal of this work is to construct a composite electrical model of Olkiluoto, focussing on integration of four separate geophysical methods: mise-a-la-masse (MAM), SAMPO EM soundings, Slingram (HLEM) and single-hole electrical soundings. The electrical structure of Olkiluoto is rather complex, dominated by mineral electrical conductors such as sulphide minerals and graphite. The basic idea of this work is the fact that the sulphide-rich zones and fracturing appear to coincide frequently. Accordingly, knowing the geometry of the major electric conductors would facilitate the interpretation of brittle deformation zones. The work consists of three separate phases: method-specific interpretation, integration and block modelling. In the single-hole interpretation, locations of electric conductors (resistivity < 1000 ohmm), based on long normal survey have been determined in 42 drillholes. Since MAM survey does not cover all the conductive sections and drillholes and SAMPO EM has its own limitations in sensitivity and resolution, a proportion of the conductive sections have been combined between the drillholes using only the single-hole data and the geological idea of features dipping gently to SE - S. The MAM survey has been done in numerous drillholes in order to find galvanic connections between the drillholes. Based on MAM, geometry of numerous electric conductors has been determined. Generally the results indicate continuous, gently dipping semiplanar features intersected by several drillholes. The Slingram survey and interpretation have been done on the ground surface to map electric conductors located at shallow depths (some tens of meters at maximum). A number of conductive zones have been delineated, trending mainly from ENE to WSW. The conductors have also been classified according to their in-phase/quadrature-ratio, and in some cases, also numerical modelling has been done. The SAMPO EM soundings and interpretations have been done to map subsurface electric

Electrical model of Olkiluoto

International Nuclear Information System (INIS)

Paananen, M.; Lehtonen, T.; Korhonen, K.

2007-05-01

The goal of this work is to construct a composite electrical model of Olkiluoto, focussing on integration of four separate geophysical methods: mise-a-la-masse (MAM), SAMPO EM soundings, Slingram (HLEM) and single-hole electrical soundings. The electrical structure of Olkiluoto is rather complex, dominated by mineral electrical conductors such as sulphide minerals and graphite. The basic idea of this work is the fact that the sulphide-rich zones and fracturing appear to coincide frequently. Accordingly, knowing the geometry of the major electric conductors would facilitate the interpretation of brittle deformation zones. The work consists of three separate phases: method-specific interpretation, integration and block modelling. In the single-hole interpretation, locations of electric conductors (resistivity < 1000 ohmm), based on long normal survey have been determined in 42 drillholes. Since MAM survey does not cover all the conductive sections and drillholes and SAMPO EM has its own limitations in sensitivity and resolution, a proportion of the conductive sections have been combined between the drillholes using only the single-hole data and the geological idea of features dipping gently to SE - S. The MAM survey has been done in numerous drillholes in order to find galvanic connections between the drillholes. Based on MAM, geometry of numerous electric conductors has been determined. Generally the results indicate continuous, gently dipping semiplanar features intersected by several drillholes. The Slingram survey and interpretation have been done on the ground surface to map electric conductors located at shallow depths (some tens of meters at maximum). A number of conductive zones have been delineated, trending mainly from ENE to WSW. The conductors have also been classified according to their in-phase/quadrature-ratio, and in some cases, also numerical modelling has been done. The SAMPO EM soundings and interpretations have been done to map subsurface electric

Interpretation of aeromagnetic survey in Eurajoensalmi, Olkiluoto (2008)

International Nuclear Information System (INIS)

Oehman, I.; Ahokas, T.; Lahti, M.

2009-06-01

In 2001, Olkiluoto was selected as the site for the final disposal of spent nuclear waste in Finland. Current construction of the underground research facility, ONKALO, is occurring at the Olkiluoto site. During the past three decades, detailed geological and geophysical investigations have been carried out on Olkiluoto Island and in the Olkiluoto vicinity in order to define its bedrock properties and structures that affect the final nuclear waste disposal. In April 2008, a high resolution aeromagnetic survey was carried out in the Eurajoensalmi inlet in order to investigate the sea and coastal areas north and west of Eurajoensalmi. Measured parameter was total magnetic field. The main goal of the survey was to improve the magnetic image of Eurajoensalmi area, to locate the area's most significant magnetic features, and by magnetic modelling find the best geological explanations for them. Some preliminary lineament interpretations were also performed to compare the accuracy of location data between lineaments interpreted in earlier surveys versus the new 2008 data. Data acquired during earlier magnetic surveys was used as reference data. Interpretation was conducted using measured total magnetic field, derivatives computed from the total field and various visualisation techniques. Comparison of data from the 1988 aeromagnetic survey conducted by GTK and the 2008 survey proves that a more detailed survey configuration sharpens anomalies and increases reliability in the interpretation of subtle features. Positioning techniques have improved significantly since the 1980's, which improves positioning accuracy and increases consistency. It can be concluded that the 2008 data is significantly more detailed and brings interpretation to a new level. Four areas, including well known bedrock structures HZ21, which corresponds to brittle deformation zone OL-BFZ002, and Liikla and Selkaenummi shear zones, were modelled. Modelling was intentionally kept relatively simple using

Geochemical evaluation of the near-field for future HLW repository at Olkiluoto

International Nuclear Information System (INIS)

Idiart, A.; Maia, F.; Arcos, D.

2013-10-01

The concept for the final disposal of spent nuclear fuel in Finland considers an engineered and natural (crystalline rock) multi-barrier system surrounding the spent fuel. This work aims at predicting and making a quantitative assessment of the geochemical evolution of the near-field (canister, buffer, backfill and adjacent fractured bedrock) during the unsaturated thermal period and in the long-term, after saturation has been completed. The groundwater/bentonite buffer interaction during the unsaturated thermal period is tackled through a two-dimensional (2D) axisymmetric scheme using the thermo-hydro-geochemical code TOUGHREACT. In turn, the long-term interaction of the fully water-saturated buffer and backfill with groundwater is assessed through 3D numerical models using the reactive transport code PHAST under isothermal conditions. A set of base cases have been set up based on the most plausible set of input data. In addition, a limited number of sensitivity cases have been conducted to analyse the influence of key parameters controlling the system and reduce uncertainty. Predicted mineralogical changes of accessory minerals in the bentonite for the thermal period are controlled by the dependence of mineral solubilities on temperature and on the solute transport by advection during the saturation process, and diffusion during the whole period. The results of the thermal period indicate that a small amount of the primary amorphous silica is redistributed in the buffer: dissolution close to the canister and precipitation close to the buffer - rock interface. Primary calcite dissolution/precipitation is minimal, remaining stable throughout the simulation time in all cases. Anhydrite precipitates near the canister due to the elevated temperature, while it dissolves from the outside of the buffer. The results indicate that there is no significant evaporation of water near the copper canister and thus no chloride salt reaches saturation. The geochemical changes of

Sampling and characterisation of groundwater colloids in ONKALO at Olkiluoto, Finland in 2007

International Nuclear Information System (INIS)

Takala, M.; Manninen, P.

2008-08-01

Colloid samples were collected from ONKALO groundwater station ONK-PVA1 in October 2007 and an additional sample was taken from groundwater station ONK-PVA3 in November 2007. The colloids were collected by filtering the groundwater on site with an Anopore 0.02 μm aluminium oxide filter. In the sampling in October, water samples were also collected to analyse the differences in the water chemistry before and after filtration. The water samples were freeze-dried so that the elements would be concentrated in the water. The colloid concentrations were determined by counting the particles from the SEM micrographs and by calculating the concentration using the micrograph area, the filter area and the filtered volume. The colloid concentration in ONK-PVA1 was very low. The particle concentration within the size range from 0.1 μm to 1 μm was 1.6 x 10 4 pt/L and the mass concentration within the same size range 0.001 μg/L. Owing to the very low concentration, an additional colloid sample was taken from ONK-PVA3. The colloid concentration in ONK-PVA3 within the size range from 0.1 μm to 1 μm was 8.2 x 10 7 pt/L and the mass concentration 0.013 mg/L. When studying the ONKALO groundwater monitoring data it was noticed that in the samples where the colloid concentration was elevated also the sodium fluorescein concentration was probably elevated. This indicated that process water (e.g. drilling water) was present in the water samples. The ONK-PVA1 water probably also contained process water during the colloid sampling performed in 2006. The composition of the colloid phase could not be determined by analysing the differences in the filtered and unfiltered water owing to the low colloid concentration. Furthermore, the aluminium oxide filter caused aluminium contamination. (orig.)

Compilation and analysis of hydrogeological pressure responses to field activities in Olkiluoto during 2006-2009

Energy Technology Data Exchange (ETDEWEB)

Vaittinen, T.; Pentti, E. [Poeyry Finland Oy, Vantaa (Finland)

2013-11-15

Groundwater flow characteristics provide essential input for the construction and safety assessment of a disposal facility for spent nuclear fuel. On the Olkiluoto site flow connections have been studied in deep drillholes by means of long-term pumping tests, various interference tests, and by interpreting the measured hydraulic heads. This report focuses on the assessment of measured hydraulic heads during 2006-2009. Hydraulic heads have been measured both in open and in packed-off drillholes since 1991. The interpretation of the hydraulic connections is based on observed changes in hydraulic head distribution caused by certain investigation activities on the site. Field activities may increase the head, e.g. drilling, or more typically decrease the head, e.g. flush pumping after drilling, difference flow logging with pumping, and both temporary and currently stable inflows into underground facilities caused by the construction of ONKALO. Processing of the head observations has been developed by determining section-specific corrections for natural fluctuation of the groundwater. The objective of the corrections is to remove natural fluctuation of the groundwater table and sea level, tidal effect, and atmospheric pressure to improve detection of changes in hydraulic head caused by field activities. Time series of observations are compared to schedules of field activities and values for responses are calculated. In addition to temporary responses head drawdown at the end of 2009 is estimated. Analysed responses are mainly related to pumpings from open drillholes and to construction of the access tunnel and the shafts through the hydrogeological HZ19 system until June 2008. Since July 2008 the strongest responses are caused by excavation of the access tunnel and pre-grouting of the shafts through the hydrogeological HZ20 system. Based on the head observations in packed-off drillholes, sub-horizontal hydraulic zones form a layered system at the ONKALO area

Compilation and analysis of hydrogeological pressure responses to field activities in Olkiluoto during 2006-2009

International Nuclear Information System (INIS)

Vaittinen, T.; Pentti, E.

2013-11-01

Groundwater flow characteristics provide essential input for the construction and safety assessment of a disposal facility for spent nuclear fuel. On the Olkiluoto site flow connections have been studied in deep drillholes by means of long-term pumping tests, various interference tests, and by interpreting the measured hydraulic heads. This report focuses on the assessment of measured hydraulic heads during 2006-2009. Hydraulic heads have been measured both in open and in packed-off drillholes since 1991. The interpretation of the hydraulic connections is based on observed changes in hydraulic head distribution caused by certain investigation activities on the site. Field activities may increase the head, e.g. drilling, or more typically decrease the head, e.g. flush pumping after drilling, difference flow logging with pumping, and both temporary and currently stable inflows into underground facilities caused by the construction of ONKALO. Processing of the head observations has been developed by determining section-specific corrections for natural fluctuation of the groundwater. The objective of the corrections is to remove natural fluctuation of the groundwater table and sea level, tidal effect, and atmospheric pressure to improve detection of changes in hydraulic head caused by field activities. Time series of observations are compared to schedules of field activities and values for responses are calculated. In addition to temporary responses head drawdown at the end of 2009 is estimated. Analysed responses are mainly related to pumpings from open drillholes and to construction of the access tunnel and the shafts through the hydrogeological HZ19 system until June 2008. Since July 2008 the strongest responses are caused by excavation of the access tunnel and pre-grouting of the shafts through the hydrogeological HZ20 system. Based on the head observations in packed-off drillholes, sub-horizontal hydraulic zones form a layered system at the ONKALO area

Safety case for the disposal of spent nuclear fuel at Olkiluoto - Synthesis 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR 2012) and application for a construction licence for a spent nuclear fuel repository. Consistent with the Government Decisions-in- Principle, this foresees a repository developed in bedrock at the Olkiluoto site according to the KBS-3 method, designed to accept spent nuclear fuel from the lifetime operations of the Olkiluoto and Loviisa reactors. Synthesis 2012 presents a synthesis of Posiva Oy's Safety Case 'TURVA-2012' portfolio. It summarises the design basis for the repository at the Olkiluoto site, the assessment methodology and key results of performance and safety assessments. It brings together all the lines of argument for safety, evaluation of compliance with the regulatory requirements, and statement of confidence in long-term safety and Posiva's safety analyses. The TURVA-2012 safety case demonstrates that the proposed repository design provides a safe solution for the disposal of spent nuclear fuel, and that the performance and safety assessments are fully consistent with all the legal and regulatory requirements related to long-term safety as set out in Government Decree 736/2008 and in guidance from the nuclear regulator - the STUK. Moreover, Posiva considers that the level of confidence in the demonstration of safety is appropriate and sufficient to submit the construction licence application to the authorities. The assessment of long-term safety includes uncertainties, but these do not affect the basic conclusions on the long-term safety of the repository. (orig.)

Colloids or artefacts? A TVO/SKB cooperation project in Olkiluoto, Finland

International Nuclear Information System (INIS)

Laaksoharju, M.; Vuorinen, U.; Snellman, M.; Helenius, J.; Allard, B.; Pettersson, C.; Hinkkanen, H.

1993-12-01

TVO (Teollisuuden Voima Oy, Finland) initiated a co-operative task with SKB (Swedish Nuclear Fuel and Waste Management Co.) to critically evaluate colloid sampling methods at the test site in Olkiluoto, SW Finland. Three different colloid sampling methods were compared when sampling borehole OL-KR1 at 613-618 m depth. One possible way to make a conservative in-situ colloid estimation is to omit the contribution from calcite precipitation which is considered to be the main artefact. When this is made the inorganic colloid content (size 1-1000 nm) in Olkiluoto is 184 ±177 ppb consisting of clay minerals, silica, pyrite, goethite and magnesium oxide; the concentration of organic substances are around 100 ppb. The in-situ colloid concentration seems to be low which is in good agreement with experiences from years of sampling in similar environment and depths. The exercise shows the many difficulties encountered when sampling colloids. Small error in the planning, pump rate selection, a lack of precautionary measures, artefact sensitivity of the method etc have a tendency to affect significantly the results on the measured ppb colliod level

Seismic network at the Olkiluoto site and microearthquake observations in 2002-2013

International Nuclear Information System (INIS)

Saari, J.; Malm, M.

2014-05-01

This report describes the structure and operation of Posiva's seismic network after the comprehensive upgrade performed in 2013 and presents a summary of its micro-earthquake observations in 2002 - 2013. Excavation of the underground rock characterisation facility called ONKALO started in 2004. Before that, in February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto. The number of seismic stations has increased gradually and communication, hardware and software have developed in over ten years. The upgrade in 2013 included data transmission, the equipment in several seismic stations, the server responsible for the data processing in Olkiluoto and software applied in operation and analysis of observations. After the upgrade Posiva's permanent seismic network consists of 17 seismic stations and 21 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas, of which the larger one, the seismic semi-regional area, includes the Olkiluoto island and its surroundings. The aim is to monitor explosions and tectonic earthquakes in regional scale inside that area. All the expected excavation induced events are assumed to occur inside the smaller target area, the seismic ONKALO block, which is a 2 km x 2 km x 2 km cube surrounding the ONKALO. An additional task of monitoring is related to safeguarding of the construction of the ONKALO.In the beginning the network monitored tectonic earthquakes in order to characterise the undisturbed baseline of seismicity in Olkiluoto. After August 2004, the network also monitored excavation induced seismicity. The first three excavation induced earthquakes were recorded in September 2005. At the moment the total number of excavation induced earthquakes is 17. During the same time about 10 000 excavation blasts were located. The

Modelling end-glacial earthquakes at Olkiluoto

International Nuclear Information System (INIS)

Faelth, B.; Hoekmark, H.

2011-02-01

The objective of this study is to obtain estimates of the possible effects that post-glacial seismic events in three verified deformation zones (BFZ100, BFZ021/099 and BFZ214) at the Olkiluoto site may have on nearby fractures in terms of induced fracture shear displacement. The study is carried out by use of large-scale models analysed dynamically with the three dimensional distinct element code 3DEC. Earthquakes are simulated in a schematic way; large planar discontinuities representing earthquake faults are surrounded by a number of smaller discontinuities which represent rock fractures in which shear displacements potentially could be induced by the effects of the slipping fault. Initial stresses, based on best estimates of the present-day in situ stresses and on state-of-the-art calculations of glacially-induced stresses, are applied. The fault rupture is then initiated at a pre-defined hypocentre and programmed to propagate outward along the fault plane with a specified rupture velocity until it is arrested at the boundary of the prescribed rupture area. Fault geometries, fracture orientations, in situ stress model and material property parameter values are based on data obtained from the Olkiluoto site investigations. Glacially-induced stresses are obtained from state-of-the-art ice-crust/mantle finite element analyses. The response of the surrounding smaller discontinuities, i.e. the induced fracture shear displacement, is the main output from the simulations

Fracture toughness properties of rocks in Olkiluoto: Laboratory measurements 2008-2009

Energy Technology Data Exchange (ETDEWEB)

Siren, T.

2012-05-15

In Olkiluoto an underground rock characterization facility (ONKALO) for the final disposal site of spent nuclear fuel has been under thorough research many years, but further knowledge is needed on fracture toughness parameters. Fracture toughness parameters are important for example in fracture mechanics prediction for Posiva's Olkiluoto Spalling Experiment (POSE). This working report describes a laboratory campaign that was done between 2008 and 2009. The campaign aimed at determining the fracture mechanics parameters as well as density and ultrasonic velocities for Olkiluoto rocks. The specimens delivered were selected by Posiva; the core showed no damage and the quality of the delivered cores was good with varying sample diameter. Most of the test samples (9 out of 12) are gneissic rock. The Mode I fracture toughness was determined using two different methods to account for two different fracturing directions. The methods are the Chevron Bend (CB) test as proposed in the ISRM Suggested Method and a method based on the Brazilian Disk (BD) experiment. The Mode II fracture toughness was determined using the Punch-Through Shear with Confining Pressure experiment on the remaining pieces from the CB testing. The scatter in the results is very large, even within one piece of core sample. Usually the scatter of results is less than 5 %. The high scatter in the data at hand is believed to be due to the very inhomogeneous nature of the rock material. The magnitude of the determined Mode I fracture toughness compares well with available reported data for medium to coarse grained granitoide rocks. However the scatter of the mode II fracture toughness values is higher than experienced on other rock types, but the variability is reasonable for the inhomogeneous rock type. Distinguishing the fracture toughness values for different anisotropy directions would require more thorough testing with quality samples at different anisotropy directions. However since fracture

Local seismic network at the Olkiluoto site. Annual Report for 2006

International Nuclear Information System (INIS)

Saari, J.; Lakio, A.

2007-05-01

In February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto. Later, in June 2004, the seismic network was expanded with two new seismic stations. At that time started the excavation of the underground characterisation facility (the ONKALO) and the basic operation procedure was changed more suitable for the demands of the new situation. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The studies include both tectonic and excavation-induced microearthquakes. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during the year 2006. Also the changes in the structure and the operation procedure of the network are described. The network has operated continuously in 2006. In the beginning of 2006, the target area of the seismic monitoring expanded to semi-regional scale. Four new seismic stations started in the beginning of February 2006. At the end of the year, two new borehole geophones were installed in order to improve the sensitivity and the depth resolution of the measurements inside the ONKALO block. This report presents also new interpretations of the excavation induced earthquakes that occurred in the ONKALO in 2005. Altogether 2041 events have been located in the Olkiluoto area, in reported time period. The magnitudes of the observed events range from ML = -1.1 to ML = 3.1 (ML magnitude in local Richter's scale). Most of them are explosions. Two of the observed events are be classified as microearthquakes. Evidence of activity that would have influence on the safety of the ONKALO, have not been found. The observed earthquakes occurred in 2006 were small, ML = -0.6 and ML= -0.9. The earthquakes relate to small movements in brittle deformation zones OL-BFZ043 and OL-BFZ034 presented in the geological model of the Olkiluoto site

Precise levelling campaigns at Olkiluoto in 2012-2013

International Nuclear Information System (INIS)

Saaranen, V.; Rouhiainen, P.

2014-08-01

In order to research vertical bedrock deformations in the Olkiluoto area, Posiva Oy and the Finnish Geodetic Institute began monitoring with precise levelling in 2003. At the moment, the measuring plan includes a loop between the GPS stations around the island, a levelling line from the island to the mainland, levelling loops over the ONKALO, the characterization facility for the final disposal of spent nuclear fuel, and VLJ, the low and intermediate level waste repository. The levelling to the mainland has been performed every fourth year and the levelling of the GPS stations every second year. The micro loops (ONKALO and VLJ) have been measured annually. In this report, we present the Olkiluoto levelling observations, performed in 2012 and 2013. Local deformations have been analysed by comparing the height differences for different years. In the Olkiluoto strait area, the height changes from 2011 to 2012 were within ± 0.1 mm. In the GPS station loop, in 2011-2013, the height of benchmark (BM) GPS3 changed + 0.69 mm. It is the only benchmark, which height has changed more than one millimetre from the year 2003. Second largest deformation happened at GPS1. Its height changed - 0.49 mm from 2011 to 2013. In the ONKALO loop, largest height change, from 2011 to 2012 was - 0.37 mm. From 2012 to 2013, the largest height changes was - 0.4 mm. In the VLJ loop, the most active deformation is related to the control benchmarks of GPS9. In 2012, these benchmarks were 0.6 mm lower level than 2011. From 2012 to 2013, both benchmarks rebounded so that deformation from 2011 to 2013 is - 0.38 mm. The other benchmarks have deformation within ± 0.11 mm, from 2011 to 2013. In 2011, a new GPS station GPS16 was established. The GPS station has three control benchmarks on bedrock and one benchmark is part of a pillar. The height of the control benchmark fastened to pillar changed one millimetre, from 2011 to 2013, relative to the control benchmarks on bedrock. (orig.)

CRIEPI and SKB cooperation report. No.11. Numerical analysis for long-term pumping test at crystalline terrain

International Nuclear Information System (INIS)

Tanaka, Yasuharu

2012-01-01

A numerical analysis code for groundwater flow in rock mass, FEGM, which was developed by CRIEPI, was applied to the analysis of a long-term pumping test conducted at Olkiluoto Island in Finland. The groundwater level, the groundwater pressure and the groundwater inflow into the observation boreholes measured under the natural condition or during the pumping test could be reproduced in numerical simulations with FEGM. From this, the effectiveness of the numerical code was confirmed. And it was found that the site-scale groundwater flow is dependent on large-scale fracture zones in crystalline terrane like Olkiluoto Island. In this study, the calculated values of the groundwater inflow into the observation boreholes as well as the groundwater level and the groundwater pressure were compared to the measured ones. As a result, the reliability of the analytical model was improved. In addition, the travel times of groundwater particles from different depths at the same point to the model boundaries were compared. And the advantage of constructing waste disposal facilities at deep underground was confirmed from the viewpoint of the travel time of groundwater. (author)

Slug-tests in PP- and PVP-holes at Olkiluoto in 2006

International Nuclear Information System (INIS)

Keskitalo, K.; Lindgren, S.

2007-11-01

As part of the program for the final disposal of the nuclear fuel waste, Posiva Oy investigates the hydrological conditions at the Olkiluoto island. The hydraulic conductivity in the shallow holes OL-PP5, OL-PP9, OL-PP36, OL-PP39, OL-PVP4A, OL-PVP4B, OL-PVP6A, OL-PVP6B and OL-PVP14 was measured in summer 2006. The length of PP-holes varies between 12 and 15 m, and the test sections (1 m) are located in the bedrock. PVP-tubes have a length up to 10 m, and the test sections (2 m) are located in the overburden. The measurements were done using the slug-test technique. In the slug-test, the hydraulic head in the borehole is abruptly changed either by pouring water into the borehole or by lowering the pressure sensor. The conductivity is interpreted based on the recovery of the water level. This report presents the field measurements and their interpretation. The interpretation has been done using the Hvorslev's method, and for reference, conductivity has also been calculated according to Thiem's equation. According to the results, hydraulic conductivity in PP-holes ranges from 10 -9 m/s to 10 -6 m/s and in PVP-tubes from 10 -8 m/s to 10 -5 m/s. The range is similar as observed in measurements of years 2002, 2004 and 2005. In general the results are consistent with the results obtained in earlier measurements. Some exceptions exist in OL-PP9, where the conductivity is lower than in the 2005 measurements, but still at the same level as in the 2002 measurements. Also, the results agree with hydraulic conductivity interpreted from the pre-pumping done in connection with the groundwater sampling. (orig.)

Olkiluoto surface hydrological modelling: Update 2012 including salt transport modelling

International Nuclear Information System (INIS)

Karvonen, T.

2013-11-01

Posiva Oy is responsible for implementing a final disposal program for spent nuclear fuel of its owners Teollisuuden Voima Oyj and Fortum Power and Heat Oy. The spent nuclear fuel is planned to be disposed at a depth of about 400-450 meters in the crystalline bedrock at the Olkiluoto site. Leakages located at or close to spent fuel repository may give rise to the upconing of deep highly saline groundwater and this is a concern with regard to the performance of the tunnel backfill material after the closure of the tunnels. Therefore a salt transport sub-model was added to the Olkiluoto surface hydrological model (SHYD). The other improvements include update of the particle tracking algorithm and possibility to estimate the influence of open drillholes in a case where overpressure in inflatable packers decreases causing a hydraulic short-circuit between hydrogeological zones HZ19 and HZ20 along the drillhole. Four new hydrogeological zones HZ056, HZ146, BFZ100 and HZ039 were added to the model. In addition, zones HZ20A and HZ20B intersect with each other in the new structure model, which influences salinity upconing caused by leakages in shafts. The aim of the modelling of long-term influence of ONKALO, shafts and repository tunnels provide computational results that can be used to suggest limits for allowed leakages. The model input data included all the existing leakages into ONKALO (35-38 l/min) and shafts in the present day conditions. The influence of shafts was computed using eight different values for total shaft leakage: 5, 11, 20, 30, 40, 50, 60 and 70 l/min. The selection of the leakage criteria for shafts was influenced by the fact that upconing of saline water increases TDS-values close to the repository areas although HZ20B does not intersect any deposition tunnels. The total limit for all leakages was suggested to be 120 l/min. The limit for HZ20 zones was proposed to be 40 l/min: about 5 l/min the present day leakages to access tunnel, 25 l/min from

Olkiluoto surface hydrological modelling: Update 2012 including salt transport modelling

Energy Technology Data Exchange (ETDEWEB)

Karvonen, T. [WaterHope, Helsinki (Finland)

2013-11-15

Posiva Oy is responsible for implementing a final disposal program for spent nuclear fuel of its owners Teollisuuden Voima Oyj and Fortum Power and Heat Oy. The spent nuclear fuel is planned to be disposed at a depth of about 400-450 meters in the crystalline bedrock at the Olkiluoto site. Leakages located at or close to spent fuel repository may give rise to the upconing of deep highly saline groundwater and this is a concern with regard to the performance of the tunnel backfill material after the closure of the tunnels. Therefore a salt transport sub-model was added to the Olkiluoto surface hydrological model (SHYD). The other improvements include update of the particle tracking algorithm and possibility to estimate the influence of open drillholes in a case where overpressure in inflatable packers decreases causing a hydraulic short-circuit between hydrogeological zones HZ19 and HZ20 along the drillhole. Four new hydrogeological zones HZ056, HZ146, BFZ100 and HZ039 were added to the model. In addition, zones HZ20A and HZ20B intersect with each other in the new structure model, which influences salinity upconing caused by leakages in shafts. The aim of the modelling of long-term influence of ONKALO, shafts and repository tunnels provide computational results that can be used to suggest limits for allowed leakages. The model input data included all the existing leakages into ONKALO (35-38 l/min) and shafts in the present day conditions. The influence of shafts was computed using eight different values for total shaft leakage: 5, 11, 20, 30, 40, 50, 60 and 70 l/min. The selection of the leakage criteria for shafts was influenced by the fact that upconing of saline water increases TDS-values close to the repository areas although HZ20B does not intersect any deposition tunnels. The total limit for all leakages was suggested to be 120 l/min. The limit for HZ20 zones was proposed to be 40 l/min: about 5 l/min the present day leakages to access tunnel, 25 l/min from

Core drilling of boreholes ONK-KR1, ONK-KR2, ONK-KR3, ONK-KR4 and ONK-PVA1 in ONKALO at Olkiluoto 2005

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-11-15

Posiva Oy submitted am application for the Decision in Principle (the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki) to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government The Finnish Parliament ratified the Decision in Principle in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. The investigation programme on the influence of grouting in ground-water chemistry will be started by Posiva. The programme consists of long-term and short-term effects of grouting and the influence of grouting at different distances from the tunnel on groundwater conditions. As a part of this Suomen Malmi oy (Smoy) core drilled four boreholes in ONKALO. The identification numbers of thee boreholes are ONK-KR1, ONK-KR2, ONK-KR3 and ONK-KR4. An additional borehole ONK-PVA1 was core drilled for long-term monitoring purposes in a place where no grouting is planned to be done.The diameter of the borehole sis 75.7 mm A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. The volume of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 16 m{sup 3} and the measured volume of the returning water was about 11 dm{sup 3} in boreholes. The deviation of the boreholes was measured with the deviation measuring instrument EMS. The main rock types are migmatitic mica gneiss and granite. Filled fractures are most common type of fractures. The average fracture frequency of the boreholes varies from 0.6 to 3.1 pcs/m. The average RQD

Core drilling of boreholes ONK-KR1, ONK-KR2, ONK-KR3, ONK-KR4 and ONK-PVA1 in ONKALO at Olkiluoto 2005

International Nuclear Information System (INIS)

Rautio, T.

2005-11-01

Posiva Oy submitted am application for the Decision in Principle (the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki) to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government The Finnish Parliament ratified the Decision in Principle in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. The investigation programme on the influence of grouting in ground-water chemistry will be started by Posiva. The programme consists of long-term and short-term effects of grouting and the influence of grouting at different distances from the tunnel on groundwater conditions. As a part of this Suomen Malmi oy (Smoy) core drilled four boreholes in ONKALO. The identification numbers of thee boreholes are ONK-KR1, ONK-KR2, ONK-KR3 and ONK-KR4. An additional borehole ONK-PVA1 was core drilled for long-term monitoring purposes in a place where no grouting is planned to be done.The diameter of the borehole sis 75.7 mm A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. The volume of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 16 m 3 and the measured volume of the returning water was about 11 dm 3 in boreholes. The deviation of the boreholes was measured with the deviation measuring instrument EMS. The main rock types are migmatitic mica gneiss and granite. Filled fractures are most common type of fractures. The average fracture frequency of the boreholes varies from 0.6 to 3.1 pcs/m. The average RQD value of

Refraction seismic surveys in the investigation trench TK3 area in Olkiluoto, Eurajoki 2004

Energy Technology Data Exchange (ETDEWEB)

Ihalainen, M. [Suomen Malmi Oy, Espoo (Finland)

2005-03-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, the ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) conducted refraction seismic surveys at Olkiluoto site in Eurajoki. The work was ordered by Posiva Oy. The field work was carried out during May and June 2004. On five profiles S70-S74 totally 1002.5 m was surveyed. The purpose of the work was to determine the overburden thickness and to study bedrock properties, e.g. eventual fractured zones. The work consisted of staking, levelling, seismic measurements, interpretation and reporting. Fieldwork and interpretation were concluded by May and June 2004. Previously in 2000 and 2002 Smoy has carried out 33.0 km of seismic surveys in the area. (orig.)

Detection of environmental change using hyperspectral remote sensing at Olkiluoto repository site

International Nuclear Information System (INIS)

Tuominen, J.; Lipping, T.

2011-03-01

In this report methods related to hyperspectral monitoring of Olkiluoto repository site are described. A short introduction to environmental remote sensing is presented, followed by more detailed description of hyperspectral imaging and a review of applications of hyperspectral remote sensing presented in the literature. The trends of future hyperspectral imaging are discussed exploring the possibilities of long-wave infrared hyperspectral imaging. A detailed description of HYPE08 hyperspectral flight campaign at the Olkiluoto region in 2008 is presented. In addition, related pre-processing and atmospheric correction methods, necessary in monitoring use, and the quality control methods applied, are described. Various change detection methods presented in the literature are described, too. Finally, a system for hyperspectral monitoring is proposed. The system is based on continued hyperspectral airborne flight campaigns and precisely defined data processing procedure. (orig.)

Summary report - development of laboratory tests and the stress- strain behaviour of Olkiluoto mica gneiss

International Nuclear Information System (INIS)

Hakala, M.; Heikkilae, E.

1997-05-01

This work summarizes the project aimed at developing and qualifying a suitable combination of laboratory tests to establish a statistically reliable stress-strain behaviour of the main rock types at Posiva Oy's detailed investigation sites for disposal of spent nuclear fuel. The work includes literature study of stress-strain behaviour of brittle rock, development and qualification of laboratory tests, suggested test procedures and interpretation methods and finally testing of Olkiluoto mica gneiss. The Olkiluoto study includes over 130 loading tests. Besides the commonly used laboratory tests, direct tensile tests, damage controlled tests and acoustic emission measurements were also carried out. (orig.) (54 refs.)

Geological Model of the Olkiluoto Site. Version 2.0

International Nuclear Information System (INIS)

Aaltonen, I.

2010-10-01

The rocks of Olkiluoto can be divided into two major classes: 1) supracrustal high-grade metamorphic rocks including various migmatitic gneisses, tonalitic-granodioriticgranitic gneisses, mica gneisses, quartz gneisses and mafic gneisses, and 2) igneous rocks including pegmatitic granites and diabase dykes. The migmatitic gneisses can further be divided into three subgroups in terms of the type of migmatite structure: veined gneisses, stromatic gneisses and diatexitic gneisses. On the basis of refolding and crosscutting relationships, the metamorphic supracrustal rocks have been subjected to polyphased ductile deformation, consisting of five stages, the D2 being locally the most intensive phase, producing thrust-related folding, strong migmatisation and pervasive foliation. In 3D modelling of the lithological units, an assumption has been made, on the basis of measurements in the outcrops, investigation trenches and drill cores, that the pervasive, composite foliation produced as a result of polyphase ductile deformation has a rather constant attitude in the ONKALO area. Consequently, the strike and dip of the foliation has been used as a tool, through which the lithologies have been correlated between the drillholes and from the surface to the drillholes. In addition, the largest ductile deformation zones and tectonic units are described in 3D model. The bedrock at the Olkiluoto site has been subjected to extensive hydrothermal alteration, which has taken place at reasonably low temperature conditions, the estimated temperature interval being from slightly over 300 deg C to less than 100 deg C. Two types of alteration can be observed: firstly, pervasive alteration and secondly fracturecontrolled alteration. Clay mineralisation and sulphidisation are the most prominent alteration events in the site area. Sulphides are located in the uppermost part of the model volume following roughly the foliation and lithological trend. Kaolinite is also mainly located in the

Geological model of the Olkiluoto site. Version 1.0

International Nuclear Information System (INIS)

Mattila, J.; Aaltonen, I.; Kemppainen, K.

2008-01-01

The rocks of Olkiluoto can be divided into two major classes: (1) supracrustal high-grade metamorphic rocks including various migmatitic gneisses, tonalitic-granodioriticgranitic gneisses, mica gneisses, quartz gneisses and mafic gneisses, and (2) igneous rocks including pegmatitic granites and diabase dykes. The migmatitic gneisses can further be divided into three subgroups in terms of the type of migmatite structure: veined gneisses, stromatic gneisses and diatexitic gneisses. On the basis of refolding and crosscutting relationships, the metamorphic supracrustal rocks have been subjected to polyphased ductile deformation, consisting of five stages, the D2 being locally the most intensive phase, producing thrust-related folding, strong migmatisation and pervasive foliation. In 3D modelling of the lithological units, an assumption has been made, on the basis of measurements in the outcrops, investigation trenches and drill cores, that the pervasive, composite foliation produced as a result of polyphase ductile deformation has a rather constant attitude in the ONKALO area. Consequently, the strike and dip of the foliation has been used as a tool, through which the lithologies have been correlated between the drillholes and from the surface to the drillholes. The bedrock at the Olkiluoto site has been subjected to extensive hydrothermal alteration, which has taken place at reasonably low temperature conditions, the estimated temperature interval being from slightly over 300 deg C to less than 100 deg C. Two types of alteration can be observed: (1) pervasive (disseminated) alteration and (2) fracture-controlled (veinlet) alteration. Kaolinisation and sulphidisation are the most prominent alteration events in the site area. Sulphides are located in the uppermost part of the model volume following roughly the lithological trend (slightly dipping to the SE). Kaolinite is also located in the uppermost part, but the orientation is opposite to the main lithological trend

Results of monitoring at Olkiluoto in 2013. Hydrology and hydrogeology

Energy Technology Data Exchange (ETDEWEB)

Vaittinen, T.; Ahokas, H.; Komulainen, J.; Nummela, J.; Pentti, E.; Turku, J. [Poeyry Finland Oy, Vantaa (Finland); Karvonen, T. [WaterHope, Helsinki (Finland); Aro, S.

2014-12-15

The impact of the construction of ONKALO is monitored by measuring and observing numerous different parameters related to hydrology, geochemistry, environment, rock mechanics and foreign materials. The Hydrological Monitoring Programme consists of the following parameters: groundwater level, hydraulic head, flow conditions in open drillholes, transverse flow, hydraulic conductivity, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff), infiltration, ground frost, leakages in tunnels, and water balance in the tunnel system and in Korvensuo Reservoir. This Report focuses on hydrogeological parameters. Other parameters, like precipitation, ground frost etc. will be reported in the Monitoring Report of Environment. Updated monitoring program was introduced in the beginning of 2012. The updated program will be used for the period before repository operation. Only minor changes were implemented. Monitoring has been carried out according to plan. This Report presents the results for the year 2013. Excavation of the access tunnel was completed in 2012. Demonstration tunnels 3 and 4 were excavated and central tunnel 1 was continued from chainage 4366-22 m to chainage 4366-60 m in 2013. Total inflow into ONKALO down to chainage 4580 m including shaft ONK-KU2 down to level -437 m was on average 35 l/min in 2013. The mapping of water leakages and moisture conditions on the tunnel walls and the ceiling has been continued. The general pattern of leakages has remained similar during the construction of ONKALO. Most significant differences are caused by seasonal effects like condensation of warm ventilation air on tunnel walls and ceiling. The changes observed in the groundwater level in observation tubes in the overburden and in shallow drillholes in the bedrock are not necessarily caused by the construction of ONKALO. However, weak indications of a local decrease in groundwater level have been observed. Effects on the head

Site-to-canister scale flow and transport in Haestholmen, Kivetty, Olkiluoto and Romuvaara

Energy Technology Data Exchange (ETDEWEB)

Poteri, A.; Laitinen, M. [VTT Energy, Espoo (Finland)

1999-05-01

Radioactive waste is originating from production of electricity in nuclear power plants. Most of the waste has only low or intermediate levels of radioactivity. However, the spent nuclear fuel is highly radioactive and it has to be isolated from the biosphere. The current nuclear waste management plan in Finland is based on direct disposal of the spent nuclear fuel deep underground. The only feasible mechanism for the radionuclides to escape from an underground repository is to be carried by the groundwater flow after the failure of waste containers. The scope of this study is to examine the groundwater flow situation and transport properties in the vicinity of the disposal canister and along the potential release paths from the repository into the biosphere. The results of this study are further applied in the site specific safety analysis of a spent fuel repository. Synthesis is made of the porous medium estimates of the groundwater flow in the regional and site scales and the detailed fracture network analysis of the flow in the canister scale. This synthesis includes estimation of the transport properties from the canister into the biosphere and flow rates around the deposition holes of the waste canisters. The modelling has been carried out for four different sites: Hastholmen, Kivetty, Olkiluoto and Romavaara. According to the simulations groundwater flow rate around the deposition holes is less than about 1 litre/a for about 75 % of the deposition holes. For about 5 % of the deposition holes the flow rates are a few litres per year or higher. The highest flow rates resulted at Hastholmen, in fresh water conditions 10 000 years after present, and at Kivetty. The transport resistances were calculated for the `worst` flow paths that might have impact on the safety of the repository. The total transport resistances from the repository into the biosphere along those flow paths varied between about 40 000 a/m and 5-10{sup 6} a/m. Most of the total transport

Precise levelling campaigns at Olkiluoto in 2006 - 2007

International Nuclear Information System (INIS)

Lehmuskoski, P.

2008-04-01

The GPS observation network of Olkiluoto was constructed in 1994 for monitoring crustal deformations in the investigation area. To fulfil a better vertical control of the GPS network, precise levellings were started in the area in autumn 2003. The GPS network was first connected at Lapijoki to the precise levelling network of Finland to control the vertical movements of the whole island of Olkiluoto. Then the GPS network was levelled. It consisted of the reserve marks of eight GPS pillars and five levelling bench marks, two of which constituted the nodal bench mark pair. The second precise levelling campaign on the area was carried out in autumn 2005. Now only the GPS network added with the antenna platforms of nine GPS pillars were levelled. Compared to the other points, the elevation difference of two reserve mark pairs had changed significantly during two years, about one millimetre. The reason may be the blasting of the rock in the neighbourhood of these points and deformation of the rock after the blasting. Inspired by the observed elevation changes in 2005, micro loops were established and levelled onto the ONKALO and the VLJ Repository in autumn 2006. The micro loops consisted of seven and five bench marks the mean interval being about 300 metres. The campaign in autumn 2007 consisted of the levellings of all measured and undestroyed points of the earlier campaigns. The most interesting results were: (1) Compared to the mean theoretical land uplift the nodal bench mark 03216 near the crossing of Olkiluodontie and Satamatie had risen in four years 2.6 mm more than the nodal bench mark of Lapijoki and 1.9 mm of this occurred within the 0.8 mm long interval which separates the island and the continent. (2) During four years the northern part of the island had risen about one millimetre more than the middle part, where the before mentioned 03216 is located. (3) The elevation differences between the bench marks of the ONKALO micro loop were changed even one

Disposal facility in Olkiluoto, description of above ground facilities in tunnel transport alternative

International Nuclear Information System (INIS)

Kukkola, T.

2006-11-01

The above ground facilities of the disposal plant on the Olkiluoto site are described in this report as they will be when the operation of the disposal facility starts in the year 2020. The disposal plant is visualised on the Olkiluoto site. Parallel construction of the deposition tunnels and disposal of the spent fuel canisters constitute the principal design basis of the disposal plant. The annual production of disposal canisters for spent fuel amounts to about 40. Production of 100 disposal canisters has been used as the capacity basis. Fuel from the Olkiluoto plant and from the Loviisa plant will be encapsulated in the same production line. The disposal plant will require an area of about 15 to 20 hectares above ground level. The total building volume of the above ground facilities is about 75000 m 3 . The purpose of the report is to provide the base for detailed design of the encapsulation plant and the repository spaces, as well as for coordination between the disposal plant and ONKALO. The dimensioning bases for the disposal plant are shown in the Tables at the end of the report. The report can also be used as a basis for comparison in deciding whether the fuel canisters are transported to the repository by a lift or a by vehicle along the access tunnel. (orig.)

Disposal facility in olkiluoto, description of above ground facilities in lift transport alternative

International Nuclear Information System (INIS)

Kukkola, T.

2006-11-01

The above ground facilities of the disposal plant on the Olkiluoto site are described in this report as they will be when the operation of the disposal facility starts in the year 2020. The disposal plant is visualised on the Olkiluoto site. Parallel construction of the deposition tunnels and disposal of the spent fuel canisters constitute the principal design basis of the disposal plant. The annual production of disposal canisters for spent fuel amounts to about 40. Production of 100 disposal canisters has been used as the capacity basis. Fuel from the Olkiluoto plant and from the Loviisa plant will be encapsulated in the same production line. The disposal plant will require an area of about 15 to 20 hectares above ground level. The total building volume of the above ground facilities is about 75000 m 3 . The purpose of the report is to provide the base for detailed design of the encapsulation plant and the repository spaces, as well as for coordination between the disposal plant and ONKALO. The dimensioning bases for the disposal plant are shown in the Tables at the end of the report. The report can also be used as a basis for comparison in deciding whether the fuel canisters are transported to the repository by a lift or by a vehicle along the access tunnel. (orig.)

Local seismic network at the Olkiluoto site. Annual report for 2010

International Nuclear Information System (INIS)

Saari, J.; Malm, M.

2011-11-01

Excavation of the underground characterisation facility (the ONKALO) started in 2004. Before that, in February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto. After that the number of seismic stations has increased gradually. In 2010 Posiva's permanent seismic network consists of 15 seismic stations and 20 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during 2010. In March 2010, the seismic network was upgraded by a new triaxial borehole seismometer in order to improve the sensitivity and the depth resolution inside the ONKALO block. The sensor is the second one inside the ONKALO. New PC for data processing and analysis with the new version of Linux operating system was installed. Also all software packages for data processing and analysis and for visualization were upgraded. The network has operated continuously in 2010. Altogether 1089 events have been located in the Olkiluoto area, in reported time period. Most of them (943) are explosions occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (895 events). The magnitudes of the observed explosions inside the semi-regional area range from M L = -1

Active Microbial Communities Inhabit Sulphate-Methane Interphase in Deep Bedrock Fracture Fluids in Olkiluoto, Finland

Directory of Open Access Journals (Sweden)

Malin Bomberg

2015-01-01

Full Text Available Active microbial communities of deep crystalline bedrock fracture water were investigated from seven different boreholes in Olkiluoto (Western Finland using bacterial and archaeal 16S rRNA, dsrB, and mcrA gene transcript targeted 454 pyrosequencing. Over a depth range of 296–798 m below ground surface the microbial communities changed according to depth, salinity gradient, and sulphate and methane concentrations. The highest bacterial diversity was observed in the sulphate-methane mixing zone (SMMZ at 250–350 m depth, whereas archaeal diversity was highest in the lowest boundaries of the SMMZ. Sulphide-oxidizing ε-proteobacteria (Sulfurimonas sp. dominated in the SMMZ and γ-proteobacteria (Pseudomonas spp. below the SMMZ. The active archaeal communities consisted mostly of ANME-2D and Thermoplasmatales groups, although Methermicoccaceae, Methanobacteriaceae, and Thermoplasmatales (SAGMEG, TMG were more common at 415–559 m depth. Typical indicator microorganisms for sulphate-methane transition zones in marine sediments, such as ANME-1 archaea, α-, β- and δ-proteobacteria, JS1, Actinomycetes, Planctomycetes, Chloroflexi, and MBGB Crenarchaeota were detected at specific depths. DsrB genes were most numerous and most actively transcribed in the SMMZ while the mcrA gene concentration was highest in the deep methane rich groundwater. Our results demonstrate that active and highly diverse but sparse and stratified microbial communities inhabit the Fennoscandian deep bedrock ecosystems.

Sampling and characterisation of groundwater colloids in ONKALO at Olkiluoto, Finland, 2011

Energy Technology Data Exchange (ETDEWEB)

Takala, M.; Ojala, S.; Jarvinen, E.; Manninen, P. [Ramboll Finland Oy, Espoo (Finland)

2012-11-15

The purpose of this study was to estimate the concentration of colloids and composition of the colloid phase on the basis of the water chemistry results of filtered and unfiltered water samples and to compare the results with the previous ones. The water samples were collected from groundwater stations ONK-PVA1 and ONK-PVA3 in October 2011. The colloid concentrations were determined from scanning electron microscopy (SEM) micrographs taken from the filters. The change in the water chemistry due to filtration was also analysed. The decrease of element concentrations due to filtration would possibly reflect the composition of the colloid phase. Because the concentration of the colloids is very low, two parallel water samples were analysed five times with an Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) analyser so that the chemical differences between the filtered and unfiltered water could be evaluated. The colloid concentration in ONK-PVA1, determined by the single particle analysis of SEM micrographs, was 6 {mu}g/l while the colloid concentration in ONK-PVA3 was 7 {mu}g/l. The colloid phase composition could not be reliably determined due to the low colloid concentration. (orig.)

Summary report - development of laboratory tests and the stress- strain behaviour of Olkiluoto mica gneiss

Energy Technology Data Exchange (ETDEWEB)

Hakala, M.; Heikkilae, E. [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Rock Engineering

1997-05-01

This work summarizes the project aimed at developing and qualifying a suitable combination of laboratory tests to establish a statistically reliable stress-strain behaviour of the main rock types at Posiva Oy`s detailed investigation sites for disposal of spent nuclear fuel. The work includes literature study of stress-strain behaviour of brittle rock, development and qualification of laboratory tests, suggested test procedures and interpretation methods and finally testing of Olkiluoto mica gneiss. The Olkiluoto study includes over 130 loading tests. Besides the commonly used laboratory tests, direct tensile tests, damage controlled tests and acoustic emission measurements were also carried out. (orig.) (54 refs.).

Site and Regional Data for Biosphere Assessment BSA-2009 Supplement to Olkiluoto Biosphere Description 2009

International Nuclear Information System (INIS)

Aro, L.; Haapanen, R.; Puhakka, L.; Hjerpe, T.; Kirkkala, T.; Koivunen, S.; Lahdenperae, A.-M.; Salo, T.; Ikonen, A.T.K.; Helin, J.

2010-06-01

The safety case for a spent nuclear fuel repository at Olkiluoto includes a computational safety assessment. A site-specific biosphere assessment is an integral part of them both. In 2009 an assessment was conducted to demonstrate preparedness to apply for construction license to the repository in 2012. As a part of the biosphere assessment, the present conditions at the site are described in Olkiluoto biosphere description report for an analogue of the future conditions being simulated in the safety assessment. This report is a supplement to the biosphere description report of 2009 and documents the site and regional data used in the biosphere assessment 'BSA-2009' with respective rationales. (orig.)

TURVA-2012 safety case for licensing a spent fuel repository at Olkiluoto, Finland

International Nuclear Information System (INIS)

Vira, Juhani; Snellman, Margit

2014-01-01

In 2001, the Finnish Parliament endorsed a decision-in-principle (DiP) whereby the spent nuclear fuel produced by the operating nuclear reactors at Olkiluoto and Loviisa will be disposed of in a geological repository at Olkiluoto, on the south-western coast of Finland. Subsequently, additional DiPs were issued allowing the extension of the repository to accommodate spent nuclear fuel from additional reactors that are under construction or in planning at Olkiluoto, which means a total of 9 000 tU of spent nuclear fuel to be disposed of. In accordance with the decision of the Ministry of Trade and Industry (KTM) in 2003, Posiva submitted an application for a license to construct a disposal facility at Olkiluoto in 2012, consisting of an encapsulation facility and an underground deep geological repository. The application included a Preliminary Safety Analysis Report (PSAR) and a long-term safety case, TURVA-2012. Assuming a positive outcome of the current licensing review, the next step would be the Final Safety Analysis Report (FSAR) in support of an operational licence application around 2020. The disposal method is based on the same KBS-3 concept that the Swedish SKB has used as basis for their license application in 2010. Accordingly, the spent nuclear fuel will be encapsulated in water- and gas-tight copper canisters equipped with a load-bearing insert and emplaced in a deep geological repository constructed in the bedrock. The canisters will be surrounded by a swelling clay buffer material that isolates them from the bedrock. The deposition tunnels and the central tunnels and the other underground openings will be backfilled with materials of low permeability. The repository will be at a depth of about 400-450 m below ground. The primary role of the bedrock is to provide sufficiently stable conditions for the engineered barrier system and to make inadvertent human intrusion unlikely. In case of EBS failure, the bedrock shall also retain and retard the possible

Understanding brittle deformation at the Olkiluoto site. Literature compilation for site characterization and geological modelling

International Nuclear Information System (INIS)

Millnes, A.G.

2006-07-01

The present report arose from the belief that geological modelling at Olkiluoto, Finland, where an underground repository for spent nuclear fuel is at present under construction, could be significantly improved by an increased understanding of the phenomena being modelled, in conjunction with the more sophisticated data acquisition and processing methods which are now being introduced. Since the geological model is the necessary basis for the rock engineering and hydrological models, which in turn provide the foundation for identifying suitable rock volumes underground and for demonstrating longterm safety, its scientific basis is of critical importance. As a contribution to improving this scientific basis, the literature on brittle deformation in the Earth's crust has been reviewed, and key references chosen and arranged, with the particular geology of the Olkiluoto site in mind. The result is a compilation of scientific articles, reports and books on some of the key topics, which are of significance for an improved understanding of brittle deformation of hard, crystalline rocks, such as those typical for Olkiluoto. The report is subdivided into six Chapters, covering (1) background information, (2) important aspects of the fabric of intact rock, (3) fracture mechanics and brittle microtectonics, (4) fracture data acquisition and processing, for the statistical characterisation and modelling of fracture systems, (5) the characterisation of brittle deformation zones for deterministic modelling, and (6) the regional geological framework of the Olkiluoto site. The Chapters are subdivided into a number of Sections, and each Section into a number of Topics. The citations are mainly collected under each Topic, embedded in a short explanatory text or listed chronologically without comment. The systematic arrangement of Chapters, Sections and Topics is such that the Table of Contents can be used to focus quickly on the theme of interest without the necessity of looking

DFN Modeling for the Safety Case of the Final Disposal of Spent Nuclear Fuel in Olkiluoto, Finland

Science.gov (United States)

Vanhanarkaus, O.

2017-12-01

Olkiluoto Island is a site in SW Finland chosen to host a deep geological repository for high-level nuclear waste generated by nuclear power plants of power companies TVO and Fortum. Posiva, a nuclear waste management organization, submitted a construction license application for the Olkiluoto repository to the Finnish government in 2012. A key component of the license application was an integrated geological, hydrological and biological description of the Olkiluoto site. After the safety case was reviewed in 2015 by the Radiation and Nuclear Safety Authority in Finland, Posiva was granted a construction license. Posiva is now preparing an updated safety case for the operating license application to be submitted in 2022, and an update of the discrete fracture network (DFN) model used for site characterization is part of that. The first step describing and modelling the network of fractures in the Olkiluoto bedrock was DFN model version 1 (2009), which presented an initial understanding of the relationships between rock fracturing and geology at the site and identified the important primary controls on fracturing. DFN model version 2 (2012) utilized new subsurface data from additional drillholes, tunnels and excavated underground facilities in ONKALO to better understand spatial variability of the geological controls on geological and hydrogeological fracture properties. DFN version 2 connected fracture geometric and hydraulic properties to distinct tectonic domains and to larger-scale hydraulically conductive fault zones. In the version 2 DFN model, geological and hydrogeological models were developed along separate parallel tracks. The version 3 (2017) DFN model for the Olkiluoto site integrates geological and hydrogeological elements into a single consistent model used for geological, rock mechanical, hydrogeological and hydrogeochemical studies. New elements in the version 3 DFN model include a stochastic description of fractures within Brittle Fault Zones (BFZ

Compilation and analysis of hydrogeological pressure responses to field activities in Olkiluoto during 2010-2012

Energy Technology Data Exchange (ETDEWEB)

Pentti, E.; Penttinen, T.; Vaittinen, T. [Poeyry Finland Oy, Vantaa (Finland)

2014-04-15

Groundwater flow characteristics provide essential input for the construction and safety assessment of a disposal facility for spent nuclear fuel. On the Olkiluoto site flow connections have been studied in deep drillholes by means of long-term pumping tests, various interference tests, and by interpreting the measured hydraulic heads. This report focuses on the assessment of measured hydraulic heads during 2010-2012. Hydraulic heads have been measured both in open and in packed-off drillholes since 1991. The interpretation of the hydraulic connections is based on observed changes in hydraulic head distribution caused by certain investigation activities on the site. Field activities may increase the head, e.g. drilling, or more typically decrease the head, e.g. flush pumping after drilling, difference flow logging with pumping, and both temporary and currently stable inflows into underground facilities caused by the construction of ONKALO. Processing of the head observations has been developed by determining section-specific corrections for natural fluctuation of the groundwater. The objective of the corrections is to remove natural fluctuation of the groundwater table and sea level, tidal effect, and atmospheric pressure to improve detection of changes in hydraulic head caused by field activities. Time series of observations are compared to schedules of field activities and values for responses are calculated. In addition to temporary responses, head drawdown at the end of 2012 is estimated as well as reasons for changes in it during 2010-2012. The temporary drawdowns during the studied period were mainly related to leaks from pregrouting holes in the vertical shafts that penetrate the hydrogeological system HZ20. Drawdowns that have so far remained resulted from the raise boring of the exhaust air shaft through the HZ20 system and from connections of low-transmissivity structures to leaks in the ONKALO at repository depth. According to present understanding, the

Slug-tests in PP- and PVP-holes at Olkiluoto in 2008

International Nuclear Information System (INIS)

Keskitalo, K.

2009-02-01

As part of the program for the final disposal of the nuclear fuel waste, Posiva Oy investigates the hydrological conditions at the Olkiluoto island. The hydraulic conductivity in the shallow holes OL-PP36, OL-PP39, OL-PVP4A, OL-PVP4B, OL-PVP6A, OL-PVP6B, OL-PVP14, OL-PVP21, OL-PVP22, OL-PVP23, OL-PVP24, OL-PVP25, OL-PVP26, OL-PVP27, OL-PVP28, OL-PVP29, OL-HP1, OL-HP2 and OL-HP4 was measured in summer 2008. The length of PP-holes was between 12 and 14 m, and the test sections (1 m) are located in the bedrock. PVP-tubes have an average length between 3 - 11 m, and the test sections (mostly 2 m) are located in the overburden. The measurements were done using the slug-test technique. In the slug-test, the hydraulic head in the borehole is abruptly changed either by pouring water into the borehole or by lowering the pressure sensor. The hydraulic conductivity is interpreted from the recovery of the water level. This report presents the field measurements and their interpretation. The interpretation has been done using the Hvorslev's method, and for reference, conductivity has also been calculated according to Thiem's equation. According to the results, hydraulic conductivity in PP-holes ranges from 10 -9 m/s to 10 -6 m/s and in PVP-tubes from 10 -8 m/s to 10 -5 m/s. The observed range is similar as in the previous measurements in 2002 and 2004 - 2007. In general, the results are consistent with the results obtained in earlier measurements. In OL-PVP14, there seems to be a lowering trend of the conductivity. In OL-PVP4A the results seem to have slight increase year after year. Also, the results agree with hydraulic conductivity interpreted from the pre-pumping done in connection with the groundwater sampling or installation of observation tubes. (orig.)

Estimating the mechanical properties of the brittle deformation zones at Olkiluoto

International Nuclear Information System (INIS)

Hudson, J.A.; Cosgrove, J.W.; Johansson, E.

2008-09-01

In rock mechanics modelling to support repository design and safety assessment for the Olkiluoto site, it is necessary to obtain the relevant rock mechanics parameters, these being an essential pre-requisite for the modelling. The parameters include the rock stress state, the properties of the intact rock and the rock mass, and the properties of the brittle deformation zones which represent major discontinuities in the rock mass continuum. However, because of the size and irregularity of the brittle deformation zones, it is not easy to estimate their mechanical properties, i.e. their deformation and strength properties. Following Section 1 explaining the motivation for the work and the objective of the Report, in Sections 2 and 3, the types of fractures and brittle deformation zones that can be encountered are described with an indication of the mechanisms that lead to complex structures. The geology at Olkiluoto is then summarized in Section 4 within the context of this Report. The practical aspects of encountering the brittle deformation zones in outcrops, drillholes and excavations are described in Sections 5 and 6 with illustrative examples of drillhole core intersections in Section 7. The various theoretical, numerical and practical methods for estimating the mechanical properties of the brittle deformation zones are described in Section 8, together with a Table summarizing each method's advantages, disadvantages and utility in estimating the mechanical properties of the zones. We emphasise that the optimal approach to estimating the mechanical properties of the brittle deformation zones cannot be determined without a good knowledge, not only of each estimation method's capabilities and idiosyncrasies, but also of the structural geology background and the specific nature of the brittle deformation zones being characterized. Finally, in Section 9, a Table is presented outlining each method's applicability to the Olkiluoto site. A flowchart is included to

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Complementary considerations 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

Complementary Considerations sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of enhancing confidence in the outcomes of the safety assessment for a spent nuclear fuel repository to be constructed at Olkiluoto, Finland. The main emphasis in this report is on the evidence and understanding that can be gained from observations at the site, including its regional geological environment, and from natural and anthropogenic analogues for the repository, its components and the processes that affect safety. In particular, the report addresses diverse and less quantifiable types of evidence and arguments that are enclosed to enhance confidence in the outcome of the safety assessment. These complementary considerations have been described as evaluations, evidence and qualitative supporting arguments that lie outside the scope of the other reports of the quantitative safety assessment. The experience with natural analogues for the long-term durability of the materials involved and the extent of processes provides high confidence in our understanding of the disposal system and its evolution. For each engineered barrier and key process, there is increasing analogue evidence to support the conceptual models and parameters. Regarding the suitability of the Olkiluoto site to host a spent fuel repository, a number of factors have been identified that indicate the suitability of crystalline host rock in general, and that of the Olkiluoto site in particular. The report also provides radiation background information for the use of complementary indicators, which aid in putting the results of the safety analysis presented in Assessment of Radionuclide Release Scenarios for the Repository System and Biosphere Assessment in a broader perspective to show that the radiation originating from a spent nuclear fuel repository remains in most cases much below natural background radiation or that caused by non-nuclear industries. (orig.)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Complementary considerations 2012

International Nuclear Information System (INIS)

2012-12-01

Complementary Considerations sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of enhancing confidence in the outcomes of the safety assessment for a spent nuclear fuel repository to be constructed at Olkiluoto, Finland. The main emphasis in this report is on the evidence and understanding that can be gained from observations at the site, including its regional geological environment, and from natural and anthropogenic analogues for the repository, its components and the processes that affect safety. In particular, the report addresses diverse and less quantifiable types of evidence and arguments that are enclosed to enhance confidence in the outcome of the safety assessment. These complementary considerations have been described as evaluations, evidence and qualitative supporting arguments that lie outside the scope of the other reports of the quantitative safety assessment. The experience with natural analogues for the long-term durability of the materials involved and the extent of processes provides high confidence in our understanding of the disposal system and its evolution. For each engineered barrier and key process, there is increasing analogue evidence to support the conceptual models and parameters. Regarding the suitability of the Olkiluoto site to host a spent fuel repository, a number of factors have been identified that indicate the suitability of crystalline host rock in general, and that of the Olkiluoto site in particular. The report also provides radiation background information for the use of complementary indicators, which aid in putting the results of the safety analysis presented in Assessment of Radionuclide Release Scenarios for the Repository System and Biosphere Assessment in a broader perspective to show that the radiation originating from a spent nuclear fuel repository remains in most cases much below natural background radiation or that caused by non-nuclear industries. (orig.)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Complementary considerations 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

Complementary Considerations sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of enhancing confidence in the outcomes of the safety assessment for a spent nuclear fuel repository to be constructed at Olkiluoto, Finland. The main emphasis in this report is on the evidence and understanding that can be gained from observations at the site, including its regional geological environment, and from natural and anthropogenic analogues for the repository, its components and the processes that affect safety. In particular, the report addresses diverse and less quantifiable types of evidence and arguments that are enclosed to enhance confidence in the outcome of the safety assessment. These complementary considerations have been described as evaluations, evidence and qualitative supporting arguments that lie outside the scope of the other reports of the quantitative safety assessment. The experience with natural analogues for the long-term durability of the materials involved and the extent of processes provides high confidence in our understanding of the disposal system and its evolution. For each engineered barrier and key process, there is increasing analogue evidence to support the conceptual models and parameters. Regarding the suitability of the Olkiluoto site to host a spent fuel repository, a number of factors have been identified that indicate the suitability of crystalline host rock in general, and that of the Olkiluoto site in particular. The report also provides radiation background information for the use of complementary indicators, which aid in putting the results of the safety analysis presented in Assessment of Radionuclide Release Scenarios for the Repository System and Biosphere Assessment in a broader perspective to show that the radiation originating from a spent nuclear fuel repository remains in most cases much below natural background radiation or that caused by non-nuclear industries. (orig.)

Game statistics for the island of Olkiluoto in 2008-2009

Energy Technology Data Exchange (ETDEWEB)

Jussila, I. (Turku Univ., Satakunta Environmental Research Inst., Pori (Finland)); Nieminen, M. (Faunatica Oy, Espoo (Finland))

2009-10-15

The game statistics for the island of Olkiluoto were updated in April 2009, and compared with earlier studies. Population size estimates are based on interviews of local hunters, and other available material. Conclusions of changes in game populations are based on rough estimates primarily from interviews, only in Elk and Deer also on inventories. Elk population is still slightly decreasing. The growth of the White-tailed Deer population is slowing down. The changes in the Roe Deer population are not precisely known, but it is seemingly varying to some extent in different years. The populations of small predators (American Mink, Raccoon Dog and Red Fox) are still strong in Olkiluoto, partly because of very dense population of voles during the hunting season. The Raccoon Dog population has been diminished due to shooting several individuals during the Elk and Deer hunting. The Red Fox population is obviously increasing. The Mountain Hare population is strong and it increased in 2008. However, the Brown Hare population is apparently decreasing, probably due to kills by mammalian predators, eagles and traffic. Currently, other game animals (e.g. waterfowl) are hardly ever hunted. (orig.)

Game statistics for the island of Olkiluoto in 2008-2009

International Nuclear Information System (INIS)

Jussila, I.; Nieminen, M.

2009-10-01

The game statistics for the island of Olkiluoto were updated in April 2009, and compared with earlier studies. Population size estimates are based on interviews of local hunters, and other available material. Conclusions of changes in game populations are based on rough estimates primarily from interviews, only in Elk and Deer also on inventories. Elk population is still slightly decreasing. The growth of the White-tailed Deer population is slowing down. The changes in the Roe Deer population are not precisely known, but it is seemingly varying to some extent in different years. The populations of small predators (American Mink, Raccoon Dog and Red Fox) are still strong in Olkiluoto, partly because of very dense population of voles during the hunting season. The Raccoon Dog population has been diminished due to shooting several individuals during the Elk and Deer hunting. The Red Fox population is obviously increasing. The Mountain Hare population is strong and it increased in 2008. However, the Brown Hare population is apparently decreasing, probably due to kills by mammalian predators, eagles and traffic. Currently, other game animals (e.g. waterfowl) are hardly ever hunted. (orig.)

Discrete fracture network modelling of a KBS-3H repository at Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Lanyon, G.W. (Fracture Systems Ltd, St Ives (United Kingdom)); Marschall, P. (Nagra, Wettingen (Switzerland))

2008-06-15

This report presents Discrete Fracture Network (DFN) models of groundwater flow around a KBS-3H repository situated at Olkiluoto. The study was performed in support of the Safety Case for the KBS-3H Concept, being jointly studied by SKB and Posiva. As part of the preliminary assessment of long term safety of a KBS-3H repository, a Process Report and an Evolution Report (evolution of the disposal system from the emplacement of the first canister to the long term) are being produced. In the course of the task definition the project team identified the need for complementary modelling studies aimed at increasing insight into the hydrodynamic evolution of the disposal system after waste emplacement. In particular, the following issues were identified as requiring input from hydrodynamic models: Probability of high inflow points which may cause buffer erosion. Time transients of inflows after construction of deposition drifts. Interference between deposition drifts and transport tunnels. The DFN models represent the fault and fracture system in the planned repository volume at Olkiluoto. In particular, they represent the hydro geologically significant features. The types of hydrogeological features included in the models are: Major Fracture Zones (MFZs). Local Fracture Zones (LFZs) and associated water conducting features (LFZ-WCFs). Water Conducting Features in the background rock (BR-WCFs). These feature types are derived from the current geological and hydrogeological interpretations developed by Posiva. Several model variants were developed during the study and these variants were used for geometric simulations of the WCF network around the deposition drifts. A simple layout adaptation scheme has been applied to the network models to derive statistics for performance measures relating to the deposition drifts, compartments, plugs and super-containers. A single fracture transient flow model was developed to provide insight to transient flow behaviour around

Discrete fracture network modelling of a KBS-3H repository at Olkiluoto

International Nuclear Information System (INIS)

Lanyon, G.W.; Marschall, P.

2008-06-01

This report presents Discrete Fracture Network (DFN) models of groundwater flow around a KBS-3H repository situated at Olkiluoto. The study was performed in support of the Safety Case for the KBS-3H Concept, being jointly studied by SKB and Posiva. As part of the preliminary assessment of long term safety of a KBS-3H repository, a Process Report and an Evolution Report (evolution of the disposal system from the emplacement of the first canister to the long term) are being produced. In the course of the task definition the project team identified the need for complementary modelling studies aimed at increasing insight into the hydrodynamic evolution of the disposal system after waste emplacement. In particular, the following issues were identified as requiring input from hydrodynamic models: Probability of high inflow points which may cause buffer erosion. Time transients of inflows after construction of deposition drifts. Interference between deposition drifts and transport tunnels. The DFN models represent the fault and fracture system in the planned repository volume at Olkiluoto. In particular, they represent the hydro geologically significant features. The types of hydrogeological features included in the models are: Major Fracture Zones (MFZs). Local Fracture Zones (LFZs) and associated water conducting features (LFZ-WCFs). Water Conducting Features in the background rock (BR-WCFs). These feature types are derived from the current geological and hydrogeological interpretations developed by Posiva. Several model variants were developed during the study and these variants were used for geometric simulations of the WCF network around the deposition drifts. A simple layout adaptation scheme has been applied to the network models to derive statistics for performance measures relating to the deposition drifts, compartments, plugs and super-containers. A single fracture transient flow model was developed to provide insight to transient flow behaviour around

Slug-tests in PP- and PVP-holes at Olkiluoto in 2009

International Nuclear Information System (INIS)

Isola, O.

2010-11-01

As part of the program for the final disposal of the nuclear fuel waste, Posiva Oy investigates the hydrological conditions at the Olkiluoto Island. The hydraulic conductivity in the shallow holes OL-PP36, OL-PP39, OL-PVP4A, OL-PVP4B, OL-PVP6A, OL-PVP6B, OL-PVP14, OL-PVP30, OL-PVP31A, OL-PVP31B, OLPVP32, OL-PVP33, OL-PVP34A, OL-PVP34B, OL-HP1, OL-HP2, OL-HP3 and OLHP4 was measured in summer 2009. The length of PP-holes was between 12 and 14 m, and the test sections (1 m) are located in the bedrock. PVP-tubes have an average length between 3 - 11 m, and the test sections (mostly 2 m) are located in the overburden. The measurements were done using the slug-test technique. In the slug-test, the hydraulic head in the borehole is abruptly changed either by pouring water into the borehole or by lowering the pressure sensor. The hydraulic conductivity is interpreted from the recovery of the water level. This report presents the field measurements and their interpretation. The interpretation has been done using the Hvorslev's method, and for reference, conductivity has also been calculated according to Thiem's equation. According to the results, hydraulic conductivity in PP-holes ranges from 10 -1 0 m/s to 10 -6 m/s and in PVP-tubes from 10 -8 m/s to 10 -5 m/s. The observed range is quite similar as in the previous measurements in 2002 and 2004 - 2008. In general, the results are consistent with the results obtained in earlier measurements. In OL-PVP14, there seems to be a lowering trend of the conductivity. Also, the results agree relatively well with hydraulic conductivity interpreted from the pre-pumping done in connection with the groundwater sampling. (orig.)

Olkiluoto site description 2006

International Nuclear Information System (INIS)

Andersson, J.; Ahokas, H.; Hudson, J.A.

2007-03-01

This second version of the Olkiluoto Site Report, produced by the OMTF (Olkiluoto Modelling Task Force), updates the Olkiluoto Site Report 2004 (Posiva 2005) with the data and knowledge obtained up to December 2005. The main product of the modelling has been to develop a descriptive model of the site (the Site Descriptive Model), i.e. a model describing the geometry, properties of the bedrock and the water and the associated interacting processes and mechanisms. For practical reasons, the Site Descriptive Model is divided into five parts: surface system, geology, rock mechanics, hydrogeology and hydrogeochemistry, which are presented in individual chapters. Four separated models are presented: the geological, rock mechanics, hydrogeological and hydrogeochemical models. The consistency between the hydrogeological and hydrogeochemical models is assessed in a joint chapter. Chapter 1 presents an outline of the report, explains the background to its development and sets out its objectives and scope. It is also introduces and explains the integrated modelling methodology, the nomenclature used in the descriptions of the models and the prediction/outcome studies. Chapter 2 provides a brief overview of the data used for producing the Site Description. Chapters 3 to 8 present the descriptive modelling, which involves interpreting data, interpolating or extrapolating between measurement points and calibrating the model against data, based on the various assumptions made about each conceptual model. Chapter 9 presents the results of the prediction/outcome studies performed during 2005 and Chapter 10 the overall consistency and confidence assessment. Overall conclusions are provided in Chapter 11. The main advances since Site Report 2004 are: A new geological model is presented in Chapter 4, representing a significant change from Bedrock Model 2003/1. There has been extensive use of geological data, whereas hydrogeological data have deliberately not been used and more

Sampling and characterisation of groundwater colloids in ONKALO at Olkiluoto, Finland 2009-2010

International Nuclear Information System (INIS)

Jaervinen, E.; Manninen, P.; Takala, M.; Vilhunen, S.

2011-04-01

The purpose of this study was to estimate the concentration of colloids and composition of the colloid phase on the basis of the water chemistry results of filtered and unfiltered water samples and to compare the results with the previous ones. The water samples were collected from groundwater stations ONK-PVA1 in December 2009 and ONKPVA5 in June 2010. The colloid concentrations were determined from scanning electron microscopy (SEM) micrographs taken from the filters. The change in the water chemistry due to filtration was also analysed. The decrease of element concentrations due to filtration would possibly reflect the composition of the colloid phase. Because the concentration of the colloids is very low, three parallel water samples were analysed three times with an Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) analyser so that the chemical differences between the filtered and unfiltered water could be evaluated. The colloid concentration in ONK-PVA1, determined by the single particle analysis of SEM micrographs, was 0.5 μg/l while the colloid concentration in ONK-PVA5 was 0.15 μg/l. The colloid phase composition could not be reliably determined due to the low colloid concentration. (orig.)

Assessment of potential perturbations to Posiva's SF repository at Olkiluoto from the ONKALO Facility

International Nuclear Information System (INIS)

Alexander, W.R.; Neall, F.B.

2007-06-01

Although the site of the proposed spent fuel repository at Olkiluoto in southwest Finland has been extensively investigated over the last fifteen years, Posiva decided to construct a rock characterisation facility (RCF) at the site to collect more detailed information on the host rock. The data provided by the ONKALO RCF will support the detailed repository design and safety assessment (SA) and will allow construction and disposal methods to be tested under relevant in situ conditions. ONKALO has been so designed that it can act as access routes and auxiliary rooms for the SF repository and so may be in use for the entire operational phase of the repository (currently up to 100 years). Extensive experience from deep mining suggests that such an extended period of operation could have a major impact on both the host rock formation and any nearby facilities, such as the SF repository, and, consequently, Posiva decided to investigate potential perturbations to the repository caused by the existence of ONKALO. A preliminary assessment was carried out in 2003, before construction of the RCF began, and this was recently partially updated in early 2006. This current report represents the most recent update of these reports and has the primary aims of: checking if the previous reports have missed any essential issues; evaluating whether the identified issues have been treated in an appropriate manner; updating the reports in the light of new information. This is carried out based on data from ONKALO itself and on improved understanding of some of the perturbation mechanisms identified in the original studies along with a consideration of newly identified processes. This report differs from the previous studies in addressing the issues in a more SA-oriented manner (for example, focussing the examination of potential perturbations on a re-worked FEP list), allowing the work reported here to be more easily dovetailed with future SA studies on the Olkiluoto repository

Mise-a-la-Masse Measurements at Olkiluoto in 2010

International Nuclear Information System (INIS)

Tarvainen, A.-M.

2010-10-01

Suomen Malmi Oy carried out Mise-a-la-Masse measurements at Olkiluoto site in Eurajoki during March-June 2010. The survey consisted of measurements in 9 drillholes and on 76 surface profiles. The measured drillholes were OL-KR11, OL-KR40, OLKR44, OL-KR45 and OL-KR49..OL-KR53. Surface measurements were carried out at 4 different areas. Current electrodes were placed in drillholes OL-KR49 - OL-KR53. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work. This report describes the field operation, the equipment and shows the obtained results and their quality. The raw and processed data are delivered digitally in Microsoft Ecxel format. (orig.)

IAEA coordinated research project (CRP). The use of selected safety indicators (concentrations, fluxes) in the assessment of radioactive waste disposal. Report 7: Site-specific natural geochemical concentrations and fluxes at four repository investigation sites in Finland for use as indicators of nuclear waste repository safety

International Nuclear Information System (INIS)

Pitkaenen, P.; Loefman, J.; Luukkonen, A.; Partamies, S.

2003-01-01

This report concerns site-specific data achieved during the studies of four Finnish candidate sites for nuclear fuel repository. The aims are to examine the level of radioactive concentrations (U, Rn, K, Rb, Cs, Ra, Th), their sources and their fluxes at different sites and at different depths, and whether differences in chemical conditions result from the geology or hydrogeology. The sites cover virtually the formation history of Finnish Precambrian bedrock and differ geochemically significantly. Romuvaara represents Archean basement gneisses with low K and U contents. Proterozoic migmatitic mica gneisses at Olkiluoto represent a very reducing geochemical environment with graphite and sulphides. Oxidising conditions have characterised the formation of early synkinematic granitoids at Kivetty and as well as anorogenic rapakivi granite Haestholmen. Particularly the rapakivi granite is enriched with incompatible elements such as K, Rb, U and Th. Hydrogeologically the sites differ as well. The inland sites, Romuvaara and Kivetty, have been above the highest shoreline since the retreat of the ice of the Weichselian glaciation, whereas the coastal sites have been below sea level. Hydraulic gradient is also higher inland than on shore. The contents of radioactive elements vary significantly between the sites and between deep and shallow groundwaters. Uranium concentrations at each site decrease mainly with the increasing depth, and they correlate relatively with bedrock contents between the sites. However, the observed exceptionally low contents are considered to result from a short water-rock interaction time in shallow groundwaters at Kivetty and from actively reducing groundwater conditions in deep groundwaters at Olkiluoto. Radon contents correlate mainly with U-concentrations, suggesting that Rn derives predominantly from dissolved U. Potassium and rubidium concentrations correlate with salinity, indicating that their main source is seawater or ancient brine

Hydrochemical stability of groundwaters surrounding a spent nuclear fuel repository in a 100,000 year perspective

International Nuclear Information System (INIS)

Puigdomeneck, I.

2001-09-01

This report is focussed on the effects of climate changes on the chemical composition of deep groundwaters. The aim of the work has been to assess the hydrochemical stability at nuclear repository sites in Finland and Sweden. Sites investigated by SKB and POSIVA have been compared. The corresponding features are important in judging how sensitive a site might be to climatic changes. Evidence for climate effects in the past on groundwater compositions has been reviewed, including isotopic and mineralogical data. There is for example evidence that glacial meltwaters are currently present at repository depths in the Fennoscandian Shield. No evidence has been found however that oxidising conditions have ever prevailed at depth, even if glacial meltwaters presumably had a substantial amount of dissolved O 2 . The depth distribution of different calcite types (and other fracture minerals) indicates stability in large-scale groundwater circulation over time. Information on past (and future) groundwater salinities has been sought after in the results of hydrological numerical models for Aespoe in Sweden and Olkiluoto in Finland. It is expected that groundwater salinities will change due to future climatic variations. The main effects will be from shoreline movements, permafrost and continental ice-sheets. In most sites the present reducing redox conditions will remain undisturbed during glacial cycles. The modelling indicated that most of the SKB suitability criteria will be met during the life-span of the repository and the groundwater composition will vary within what is observed in the samples collected today at various depths. The expected changes are therefore not judged to threaten the integrity and functioning of the repository. The major conclusion is that despite long-term hydrodynamic changes hydrochemical stability is expected to dominate at repository depth

Hydrochemical stability of groundwaters surrounding a spent nuclear fuel repository in a 100,000 year perspective

Energy Technology Data Exchange (ETDEWEB)

Puigdomeneck, I. (ed.)

2001-09-01

This report is focussed on the effects of climate changes on the chemical composition of deep groundwaters. The aim of the work has been to assess the hydrochemical stability at nuclear repository sites in Finland and Sweden. Sites investigated by SKB and POSIVA have been compared. The corresponding features are important in judging how sensitive a site might be to climatic changes. Evidence for climate effects in the past on groundwater compositions has been reviewed, including isotopic and mineralogical data. There is for example evidence that glacial meltwaters are currently present at repository depths in the Fennoscandian Shield. No evidence has been found however that oxidising conditions have ever prevailed at depth, even if glacial meltwaters presumably had a substantial amount of dissolved O{sub 2}. The depth distribution of different calcite types (and other fracture minerals) indicates stability in large-scale groundwater circulation over time. Information on past (and future) groundwater salinities has been sought after in the results of hydrological numerical models for Aespoe in Sweden and Olkiluoto in Finland. It is expected that groundwater salinities will change due to future climatic variations. The main effects will be from shoreline movements, permafrost and continental ice-sheets. In most sites the present reducing redox conditions will remain undisturbed during glacial cycles. The modelling indicated that most of the SKB suitability criteria will be met during the life-span of the repository and the groundwater composition will vary within what is observed in the samples collected today at various depths. The expected changes are therefore not judged to threaten the integrity and functioning of the repository. The major conclusion is that despite long-term hydrodynamic changes hydrochemical stability is expected to dominate at repository depth.

Hydrochemical stability of groundwaters surrounding a spent nuclear fuel repository in a 100,000 year perspective

Energy Technology Data Exchange (ETDEWEB)

Puigdomenech, I. (ed.); Gurban, I.; Laaksoharju, M. [and others

2001-12-01

This report is focused on the effects of climate changes on the chemical composition of deep groundwaters. The aim of the work has been to assess the hydrochemical stability at nuclear repository sites in Finland and Sweden. Sites investigated by SKB and POSIVA have been compared. The corresponding features are important in judging how sensitive a site might be to climatic changes. Evidence for climate effects in the past on groundwater compositions has been reviewed, including isotopic and mineralogical data. There is for example evidence that glacial meltwaters are currently present at repository depths in the Fennoscandian Shield. No evidence has been found however that oxidising conditions have ever prevailed at depth, even if glacial meltwaters presumably had a substantial amount of dissolved 0{sub 2}. The depth distribution of different calcite types (and other fracture minerals) indicates stability in large-scale groundwater circulation over time. Information on past (and future) groundwater salinities has been sought after in the results of hydrological numerical models for Aespoe in Sweden and Olkiluoto in Finland. It is expected that groundwater salinities will change due to future climatic variations. The main effects will be from shoreline movements, permafrost and continental ice-sheets. In most sites the present reducing redox conditions will remain undisturbed during glacial cycles. The modelling indicated that most of the SKB suitability criteria will be met during the life-span of the repository and the groundwater composition will vary within what is observed in the samples collected today at various depths. The expected changes are therefore not judged to threaten the integrity and functioning of the repository. The major conclusion is that despite long-term hydrodynamic changes hydrochemical stability is expected to dominate at repository depth. (orig.)

Nuclear power plant Olkiluoto 3. Containment leakage test under extreme conditions

Energy Technology Data Exchange (ETDEWEB)

Fleckenstein, Tobias [TUEV SUED Industrie Service GmbH, Munich (Germany). Measaruement Technology Dept.

2015-01-15

Modern nuclear power plants place high demands on the design and execution of safety checks. TUEV SUED supported the containment leakage test for the largest- capacity third generation nuclear power plant in the world - Olkiluoto 3 in Finland. The experts successfully met the challenges presented by exceptional parameters of the project. The containment of Olkiluoto 3 is unique in that the vessel's volume is 80,000 m{sup 3} while measurements were carried out over a period of ten days. To execute the test, 75 temperature and 15 humidity sensors had to be installed and correctly interlinked by more than ten kilometres of cable. These instruments also needed to withstand an absolute pressure of 6 bar, ambient temperatures of 30 C and high levels of humidity. These conditions required comprehensive preparation and a high amount of qualification tests. Parts of the qualifications were carried out at the autoclave system of the Technical University in Munich, Germany, where the project test conditions could be simulated. The software required to determine the tests was developed by TUEV SUED and verified by German's national accreditation body DAkkS under ISO 17025. TUEV SUED enabled the test schedule to continue without delay by analysing all recorded data continuously on site, including pressure, temperature, humidity and leakage mass flow curves. With the comprehensive preparation, data acquisition system recording measurements continuously and the on-time result calculation, all components of the leak-tightness assessment were successfully completed in accordance with requirements.

On detonation dynamics in hydrogen-air-steam mixtures: Theory and application to Olkiluoto reactor building

International Nuclear Information System (INIS)

Silde, A.; Lindholm, I.

2000-02-01

This report consists of the literature study of detonation dynamics in hydrogen-air-steam mixtures, and the assessment of shock pressure loads in Olkiluoto 1 and 2 reactor building under detonation conditions using the computer program DETO developed during this work at VTT. The program uses a simple 1-D approach based on the strong explosion theory, and accounts for the effects of both the primary or incident shock and the first (oblique or normal) reflected shock from a wall structure. The code results are also assessed against a Balloon experiment performed at Germany, and the classical Chapman-Jouguet detonation theory. The whole work was carried out as a part of Nordic SOS-2.3 project, dealing with severe accident analysis. The initial conditions and gas distribution of the detonation calculations are based on previous severe accident analyses by MELCOR and FLUENT codes. According to DETO calculations, the maximum peak pressure in a structure of Olkiluoto reactor building room B60-80 after normal shock reflection was about 38.7 MPa if a total of 3.15 kg hydrogen was assumed to burned in a distance of 2.0 m from the wall structure. The corresponding pressure impulse was about 9.4 kPa-s. The results were sensitive to the distance used. Comparison of the results to classical C-J theory and the Balloon experiments suggested that DETO code represented a conservative estimation for the first pressure spike under the shock reflection from a wall in Olkiluoto reactor building. Complicated 3-D phenomena of shock wave reflections and focusing, nor the propagation of combustion front behind the shock wave under detonation conditions are not modeled in the DETO code. More detailed 3-D analyses with a specific detonation code are, therefore, recommended. In spite of the code simplifications, DETO was found to be a beneficial tool for simple first-order assessments of the structure pressure loads under the first reflection of detonation shock waves. The work on assessment

Meteorological data at Olkiluoto in period of 2002-2004

International Nuclear Information System (INIS)

Ikonen, A.T.

2005-07-01

In this working report the data of some routine field observations of Posiva Oy and automatic measurements of the Olkiluoto nuclear power plant weather station owned and operated by Teollisuuden Voima Oy is published for further reference. The data reported here covers observations from 2002 to 2004. First, a concise description of data acquisition methods and handling is provided. Thereafter the actual data is presented in the appendices. Weather measurements (e.g. temperature, wind speed and direction, humidity) and snow, ground frost and ditch flow rate observations are reported. (orig.)

Surface 3-D reflection seismics - implementation at the Olkiluoto site

Energy Technology Data Exchange (ETDEWEB)

Saksa, P.; Lehtimaeki, T.; Heikkinen, E. [Poeyry Environment Oy, Vantaa (Finland)

2007-03-15

Posiva Oy takes care of the final disposal of spent nuclear fuel in Finland. In year 2001 Olkiluoto was selected for the site of final disposal. Construction of the underground research facility, ONKALO, is going on at the Olkiluoto site. The aim of this work was to study the possibilities for surface 3-D seismics and to review experiences for design before field work. The physical parameters and geometric properties of the site, as well as efficient survey layout and source arrangements, were considered in this work. Reflection seismics is most used geophysical investigation method in oil exploration and earth studies in sedimentary environment. Recently method has also been applied in crystalline bedrock for ore exploration and nuclear waste disposal site investigations. The advantage of the method is high accuracy combined with large depth of investigation. The principles of seismic 2-D and 3-D soundings are well known and advanced. 3-D sounding is a straightforward expansion of 2-D line based surveying. In investigation of crystalline bedrock, the high frequency wave sources and receivers, their right use in measurements and careful processing procedure (refraction static corrections in particular) are important. Using the site parameters in 2-D numerical modeling, two cases of faulted thin layer at depths of 200, 400 and 600 meters were studied. The first case was a layer with vertical dislocation (a ramp) and the other a layer having limited width of dislocated part. Central frequencies were 100, 200, 400 and 700 Hz. Results indicate that 10 - 20 m dislocation is recognizable, but for depths greater than 600 m, over 20 meters is required. Width of the dislocated part will affect the detectability of vertical displacement. At depths of 200 m and 400 m 10 - 50 m wide parts appear as point-like scatterers, wider areas have more continuity. Dislocations larger than 20 m can be seen. From depth of 600 m over 100 m wide parts are discernible, narrower are visible

Surface 3-D reflection seismics - implementation at the Olkiluoto site

International Nuclear Information System (INIS)

Saksa, P.; Lehtimaeki, T.; Heikkinen, E.

2007-03-01

Posiva Oy takes care of the final disposal of spent nuclear fuel in Finland. In year 2001 Olkiluoto was selected for the site of final disposal. Construction of the underground research facility, ONKALO, is going on at the Olkiluoto site. The aim of this work was to study the possibilities for surface 3-D seismics and to review experiences for design before field work. The physical parameters and geometric properties of the site, as well as efficient survey layout and source arrangements, were considered in this work. Reflection seismics is most used geophysical investigation method in oil exploration and earth studies in sedimentary environment. Recently method has also been applied in crystalline bedrock for ore exploration and nuclear waste disposal site investigations. The advantage of the method is high accuracy combined with large depth of investigation. The principles of seismic 2-D and 3-D soundings are well known and advanced. 3-D sounding is a straightforward expansion of 2-D line based surveying. In investigation of crystalline bedrock, the high frequency wave sources and receivers, their right use in measurements and careful processing procedure (refraction static corrections in particular) are important. Using the site parameters in 2-D numerical modeling, two cases of faulted thin layer at depths of 200, 400 and 600 meters were studied. The first case was a layer with vertical dislocation (a ramp) and the other a layer having limited width of dislocated part. Central frequencies were 100, 200, 400 and 700 Hz. Results indicate that 10 - 20 m dislocation is recognizable, but for depths greater than 600 m, over 20 meters is required. Width of the dislocated part will affect the detectability of vertical displacement. At depths of 200 m and 400 m 10 - 50 m wide parts appear as point-like scatterers, wider areas have more continuity. Dislocations larger than 20 m can be seen. From depth of 600 m over 100 m wide parts are discernible, narrower are visible

Geochemical controls on shale groundwaters: Results of reaction path modeling

International Nuclear Information System (INIS)

Von Damm, K.L.; VandenBrook, A.J.

1989-03-01

The EQ3NR/EQ6 geochemical modeling code was used to simulate the reaction of several shale mineralogies with different groundwater compositions in order to elucidate changes that may occur in both the groundwater compositions, and rock mineralogies and compositions under conditions which may be encountered in a high-level radioactive waste repository. Shales with primarily illitic or smectitic compositions were the focus of this study. The reactions were run at the ambient temperatures of the groundwaters and to temperatures as high as 250/degree/C, the approximate temperature maximum expected in a repository. All modeling assumed that equilibrium was achieved and treated the rock and water assemblage as a closed system. Graphite was used as a proxy mineral for organic matter in the shales. The results show that the presence of even a very small amount of reducing mineral has a large influence on the redox state of the groundwaters, and that either pyrite or graphite provides essentially the same results, with slight differences in dissolved C, Fe and S concentrations. The thermodynamic data base is inadequate at the present time to fully evaluate the speciation of dissolved carbon, due to the paucity of thermodynamic data for organic compounds. In the illitic cases the groundwaters resulting from interaction at elevated temperatures are acid, while the smectitic cases remain alkaline, although the final equilibrium mineral assemblages are quite similar. 10 refs., 8 figs., 15 tabs

Rock mechanics stability at Olkiluoto, Haestholmen, Kivetty and Romuvaara

International Nuclear Information System (INIS)

Johansson, E.; Rautakorpi, J.

2000-02-01

Posiva Oy is studying the suitability of the Finnish bedrock for the geological disposal of spent nuclear fuel at four sites, Olkiluoto in Eurajoki, Haestholmen in Loviisa, Kivetty in Aeaenekoski and Romuvaara in Kuhmo. To enable the rock properties to be specified in great detail, the site-selection research programme has included rock mechanics investigations such as the measurement of in-situ rock stress and laboratory tests on rock samples. This report presents the results of the rock mechanics analyses performed on the main rock types at the Olkiluoto, Romuvaara, Kivetty and Haestholmen sites. The objective of this study was to assess the near-field stability of the final disposal tunnels and deposition holes at each of the investigation sites. Two empirical methods and a numerical method based on three-dimensional element code (3DEC) were used the analysis tools. A statistical approach was used to select the necessary input data and to specify the cases being analysed. The stability of the KBS-3 and MLH (Medium Long Hole) repository concepts during the pre-closure and post-closure phases was analysed. The repository depths investigated lay between 300 m and 700 m. The empirical methods are based on the study of the ratios between rock strength and the in-situ stress which could result in possible fracturing of the rock mass. Interpretation of the numerical analyses is based on the assumption of an elastic distribution of stress around the disposal tunnel and the deposition hole and the brittle rock strength criterion. The results obtained in this study indicate that in general, the rock mechanics conditions during the pre-closure and post-closure phases at each of the investigated sites remain good and stable between the studied depth levels, especially when the deposition rooms are oriented in a direction parallel to the major in-situ stress. If the disposal tunnels are orientated in a direction perpendicular to the major in-situ stress, the resultant

Local seismic network at the Olkiluoto site. Annual report for 2009

International Nuclear Information System (INIS)

Saari, J.; Malm, M.

2010-06-01

Excavation of the underground characterisation facility (the ONKALO) started in 2004. Before that, in February 2002, Posiva Oy established a local seismic network of six stations on the island of Olkiluoto. After that the number of seismic stations has increased gradually. In 2009 Posiva's seismic network consists of 14 seismic stations and 19 triaxial sensors. The purpose of the microearthquake measurements at Olkiluoto is to improve understanding of the structure, behaviour and long term stability of the bedrock. The investigation area includes two target areas. The larger target area, called seismic semiregional area, covers the Olkiluoto Island and its surroundings. The purpose is to monitor explosions and tectonic earthquakes in regional scale inside that area. The smaller target area is called the seismic ONKALO block, which is a 2 km *2 km *2 km cube surrounding the ONKALO. It is assumed that all the expected excavation induced events occur within this volume. At the moment the seismic ONKALO block includes ten seismic stations. An additional task of monitoring is related to safeguarding of the ONKALO. This report gives the results of microseismic monitoring during 2009. Also the changes in the structure and the operation procedure of the network are described. The upgrades in 2009 are limited to the processing, interpretation and reporting practices. The latest upgrades of the equipment were done in November 2008. The final technical tuning and tests related to the upgrade were done in the beginning of 2009. The network has operated continuously in 2009. Altogether 1256 events have been located in the Olkiluoto area, in reported time period. Most of them (1161) are explosions occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (1135 events). The magnitudes of the observed events inside the semi-regional area range from ML = -1.5 to ML = 1.6 (ML = magnitude in local Richter's scale). Most of them are explosions. Two

Plan for safety case of spent fuel repository at Olkiluoto

International Nuclear Information System (INIS)

Vieno, T.; Ikonen, A.T.K.

2005-02-01

Posiva aims to present the Safety Case supporting the construction license application of the spent fuel repository at Olkiluoto by 2012. An outline and preliminary assessments will be presented in 2009. Interim reporting and an update of the Safety Case plan will be presented in 2006, as required by the authorities. The KBS-3 disposal concept aims at long-term isolation and containment of spent fuel assemblies in durable copper-iron canisters emplaced in a repository to be constructed at a depth between 400 and 600 metres in crystalline bedrock. By 2012, studies on the KBS-3 disposal concept and site investigations at Olkiluoto will have been continued over about thirty years. The construction of an underground rock characterisation facility (called ONKALO) was started in June 2004. The investigations are carried out in close cooperation with the Swedish SKB developing and assessing the same disposal concept at candidate sites, resembling Olkiluoto, at the other side of the Baltic Sea. A safety case is the synthesis of evidence, analyses and arguments that quantify and substantiate the safety, and the level of expert confidence in the safety, of a planned repository. Posiva's Safety Case will be organised in a portfolio including ten main reports, which will be periodically updated according the overall schedule presented in the plan. The Site report describing the present state and past evolution of the Olkiluoto site, as well as the disturbances caused by the construction of ONKALO and the first stage of the repository, forms the geoscientific basis of the Safety Case. The engineering basis is provided by the reports on the Characteristics of spent fuel, Canister design, and Repository design. The Process report containing descriptions and analyses of features, events and processes potentially affecting the disposal system, and the report on the Evolution of site and repository form the scientific basis of the Safety Case. The latter report will describe and

Geological ductile deformation mapping at the Olkiluoto site, Eurajoki, Finland

Energy Technology Data Exchange (ETDEWEB)

Engstroem, J. [Geological Survey of Finland, Espoo (Finland)

2013-12-15

During 2010-2012 eight larger excavated and cleaned outcrops were investigated to study the polyphase nature of the ductile deformation within the Olkiluoto Island. A detailed structural geological mapping together with a thin section study was performed to get a broader and better understanding of the nature and occurrence of these different ductile deformation phases. These outcrops were selected to represent all different ductile deformation phases recognized earlier during the site investigations. The relicts of primary sedimentary structures and products of the earliest deformations (D{sub 0}-D{sub 1}) are mostly obscured by later deformation events. The D{sub 2}-D{sub 4} is the most significant ductile deformation phases occurring on the Olkiluoto Island and almost all structural features can be labeled within these three phases. The outcrops for this investigation were selected mostly from the eastern part of the Olkiluoto Island because that part of the Island has been less investigated previously. As a reference, one outcrop was selected in the western part of the Island where it was previously known that this location had especially well preserved structures of the second deformation phase (D{sub 2}). The S{sub 2} foliation is E-W orientated with moderate dip towards south. A few folds can be associated with this deformational event, mostly having a tight to isoclinal character. During D{sub 3} the migmatites were re-deformed and migrated leucosomes, were intruded mainly parallel to S{sub 3} axial surfaces having a NE-SW orientation. Generally the dip of the S{sub 3} axial surfaces is slightly more steeper (55- 65 deg C) than that of the S{sub 2} axial surfaces, which shows a more moderate dip (40-65 deg C). F{sub 3} fold structures are quite common in the eastern part of Island showing asymmetrical, overturned, shear folds usually with a dextral sense of shear. Large scale D{sub 3} shear structures contain blastomylonites as characteristic fault rocks

Flow measurements and hydraulic interference tests at the Olkiluoto site in Eurajoki, drillholes OL-KR14, OL-KR30, OL-PP66, OL-PP67, OL-PP68 and OL-PP69

Energy Technology Data Exchange (ETDEWEB)

Komulainen, J. [Poeyry Finland Oy, Vantaa (Finland)

2014-08-15

The measurements described in this report are part of the infiltration experiment carried out at Olkiluoto. The emphasis of these measurements is on obtaining more detailed data on hydraulically significant fractures in the infiltration experiment area. The selected fractures or sections were pumped in turn and flow responses were observed in the other holes by the PFL DIFF-tool. The flow measurements were carried out in drillholes OL-KR14, OL-KR30, OL-PP66, OL-PP67, OL-PP68 and OL-PP69 on the Olkiluoto investigation site between January 2013 and July 2013. Two different flowmeters were used for the measurements. Posiva Flow Log, Difference flow method (PFL DIFF) was used for the determination of hydraulic conductivity and hydraulic head in fractures/fractured zones in the drillholes. PFL DIFF flow logging was conducted in all the drillholes mentioned above. Posiva Flow Log, Transverse flow method (PFL TRANS) was used to determine groundwater flow direction and flow rate across a drillhole. The transverse flow method was used in drillholes OL-KR14 and OL-PP69. PFL DIFF and PFL TRANS measurements had been carried out earlier in drillholes OL-PP66, OL-PP67, OL-PP68 and OL-PP69. The most recent measurements were conducted in 2011. Those measurements were carried out when drillhole OL-KR14 was pumped at packed-off section 13 m - 18 m. Both PFL DIFF and PFL TRANS flowmeters include an electrode for measuring single point resistance (SPR). The device has a high depth resolution and the results were used for depth synchronisation between consecutive DIFF and TRANS measurements. (orig.)

Understanding brittle deformation at the Olkiluoto site. Literature Supplement 2010: an Update of Posiva Working Report 2006-25

Energy Technology Data Exchange (ETDEWEB)

Milnes, A. (GEA Consulting, Corcelles (CH))

2011-07-15

Posiva Working Report 2006-25 arose from the belief that geological modelling at Olkiluoto, Finland, where an underground repository for spent nuclear fuel is at present under construction, could be significantly improved by an increased understanding of the phenomena being modelled, in conjunction with the more sophisticated data acquisition and processing methods which are now being introduced. Since the geological model is the necessary basis for the rock engineering and hydrological models, which in turn provide the foundation for identifying suitable rock volumes underground and for demonstrating long-term safety, its scientific basis is of critical importance. As a contribution to improving this scientific basis, the literature on brittle deformation in the Earth's crust was reviewed up to and including year 2005. The result was a compilation of scientific articles, reports and books on some of the key topics of significance for an improved understanding of brittle deformation of hard, crystalline rocks, particularly heterogeneous migmatitic and metamorphic rocks like those that make up the Olkiluoto bedrock. The present report is a supplement to WR 2006-25, covering the 5-year period 2006-2010, with some key earlier references and an Annotated Bibliography. The present report is subdivided into five chapters, listing recent literature on (1) background subjects and basic principles, (2) the fabric of Olkiluoto-type intact rock (gneisses, migmatites, fault rocks), (3) formation and characteristics of brittle deformation features (fracture mechanics, brittle microtectonics), (4) fracture data acquisition and processing (statistical characterisation and modelling of fracture systems), and (5) the characterisation of brittle deformation zones (for deterministic and dynamic modelling), corresponding to the first five chapters of the earlier report

Understanding brittle deformation at the Olkiluoto site. Literature Supplement 2010: an Update of Posiva Working Report 2006-25

International Nuclear Information System (INIS)

Milnes, A.

2011-07-01

Posiva Working Report 2006-25 arose from the belief that geological modelling at Olkiluoto, Finland, where an underground repository for spent nuclear fuel is at present under construction, could be significantly improved by an increased understanding of the phenomena being modelled, in conjunction with the more sophisticated data acquisition and processing methods which are now being introduced. Since the geological model is the necessary basis for the rock engineering and hydrological models, which in turn provide the foundation for identifying suitable rock volumes underground and for demonstrating long-term safety, its scientific basis is of critical importance. As a contribution to improving this scientific basis, the literature on brittle deformation in the Earth's crust was reviewed up to and including year 2005. The result was a compilation of scientific articles, reports and books on some of the key topics of significance for an improved understanding of brittle deformation of hard, crystalline rocks, particularly heterogeneous migmatitic and metamorphic rocks like those that make up the Olkiluoto bedrock. The present report is a supplement to WR 2006-25, covering the 5-year period 2006-2010, with some key earlier references and an Annotated Bibliography. The present report is subdivided into five chapters, listing recent literature on (1) background subjects and basic principles, (2) the fabric of Olkiluoto-type intact rock (gneisses, migmatites, fault rocks), (3) formation and characteristics of brittle deformation features (fracture mechanics, brittle microtectonics), (4) fracture data acquisition and processing (statistical characterisation and modelling of fracture systems), and (5) the characterisation of brittle deformation zones (for deterministic and dynamic modelling), corresponding to the first five chapters of the earlier report

Prediction of Groundwater Quality Trends Resulting from Anthropogenic Changes in Southeast Florida.

Science.gov (United States)

Yi, Quanghee; Stewart, Mark

2018-01-01

The effects of surface water flow system changes caused by constructing water-conservation areas and canals in southeast Florida on groundwater quality under the Atlantic Coastal Ridge was investigated with numerical modeling. Water quality data were used to delineate a zone of groundwater with low total dissolved solids (TDS) within the Biscayne aquifer under the ridge. The delineated zone has the following characteristics. Its location generally coincides with an area where the Biscayne aquifer has high transmissivities, corresponds to a high recharge area of the ridge, and underlies a part of the groundwater mound formed under the ridge prior to completion of the canals. This low TDS groundwater appears to be the result of pre-development conditions rather than seepage from the canals constructed after the 1950s. Numerical simulation results indicate that the time for low TDS groundwater under the ridge to reach equilibrium with high TDS surface water in the water-conservation areas and Everglades National Park are approximately 70 and 60 years, respectively. The high TDS groundwater would be restricted to the water-conservation areas and the park due to its slow eastward movement caused by small hydraulic gradients in Rocky Glades and its mixing with the low TDS groundwater under the high-recharge area of the ridge. The flow or physical boundary conditions such as high recharge rates or low hydraulic conductivity layers may affect how the spatial distribution of groundwater quality in an aquifer will change when a groundwater flow system reaches equilibrium with an associated surface water flow system. © 2017, National Ground Water Association.

The estimation of future surface water bodies at Olkiluoto area based on statistical terrain and land uplift models

Energy Technology Data Exchange (ETDEWEB)

Pohjola, J.; Turunen, J.; Lipping, T. [Tampere Univ. of Technology (Finland); Ikonen, A.

2014-03-15

In this working report the modelling effort of future landscape development and surface water body formation at the modelling area in the vicinity of the Olkiluoto Island is presented. Estimation of the features of future surface water bodies is based on probabilistic terrain and land uplift models presented in previous working reports. The estimation is done using a GIS-based toolbox called UNTAMO. The future surface water bodies are estimated in 10 000 years' time span with 1000 years' intervals for the safety assessment of disposal of spent nuclear fuel at the Olkiluoto site. In the report a brief overview on the techniques used for probabilistic terrain modelling, land uplift modelling and hydrological modelling are presented first. The latter part of the report describes the results of the modelling effort. The main features of the future landscape - the four lakes forming in the vicinity of the Olkiluoto Island - are identified and the probabilistic model of the shoreline displacement is presented. The area and volume of the four lakes is modelled in a probabilistic manner. All the simulations have been performed for three scenarios two of which are based on 10 realizations of the probabilistic digital terrain model (DTM) and 10 realizations of the probabilistic land uplift model. These two scenarios differ from each other by the eustatic curve used in the land uplift model. The third scenario employs 50 realizations of the probabilistic DTM while a deterministic land uplift model, derived solely from the current land uplift rate, is used. The results indicate that the two scenarios based on the probabilistic land uplift model behave in a similar manner while the third model overestimates past and future land uplift rates. The main features of the landscape are nevertheless similar also for the third scenario. Prediction results for the volumes of the future lakes indicate that a couple of highly probably lake formation scenarios can be identified

The estimation of future surface water bodies at Olkiluoto area based on statistical terrain and land uplift models

International Nuclear Information System (INIS)

Pohjola, J.; Turunen, J.; Lipping, T.; Ikonen, A.

2014-03-01

In this working report the modelling effort of future landscape development and surface water body formation at the modelling area in the vicinity of the Olkiluoto Island is presented. Estimation of the features of future surface water bodies is based on probabilistic terrain and land uplift models presented in previous working reports. The estimation is done using a GIS-based toolbox called UNTAMO. The future surface water bodies are estimated in 10 000 years' time span with 1000 years' intervals for the safety assessment of disposal of spent nuclear fuel at the Olkiluoto site. In the report a brief overview on the techniques used for probabilistic terrain modelling, land uplift modelling and hydrological modelling are presented first. The latter part of the report describes the results of the modelling effort. The main features of the future landscape - the four lakes forming in the vicinity of the Olkiluoto Island - are identified and the probabilistic model of the shoreline displacement is presented. The area and volume of the four lakes is modelled in a probabilistic manner. All the simulations have been performed for three scenarios two of which are based on 10 realizations of the probabilistic digital terrain model (DTM) and 10 realizations of the probabilistic land uplift model. These two scenarios differ from each other by the eustatic curve used in the land uplift model. The third scenario employs 50 realizations of the probabilistic DTM while a deterministic land uplift model, derived solely from the current land uplift rate, is used. The results indicate that the two scenarios based on the probabilistic land uplift model behave in a similar manner while the third model overestimates past and future land uplift rates. The main features of the landscape are nevertheless similar also for the third scenario. Prediction results for the volumes of the future lakes indicate that a couple of highly probably lake formation scenarios can be identified with other

Eurajoki Olkiluoto study on species of ground beetles and ants 2008

International Nuclear Information System (INIS)

Santaharju, J.; Helminen, S.-L.; Yrjoelae, R.

2009-02-01

The species of ants and Ground beetles at Olkiluoto in Eurajoki were studied in the summer of 2008 during two trapping periods: in June and August. The research goal was to clarify the species on Olkiluoto island of the earlier mentioned groups, at least at the family level, and to collect samples for further examination by Posiva. The trapping areas were selected at Olkiluoto in Posiva test monitoring sectors, a part of the trapping areas was the same as the earlier study. Species of ants, depending on their particular species, are a very dominating group of insects. The ants are the most important predators, scavengers and soil movers in Finnish forests. It looks as if the biomass of ants may be more than 10% of the biomass of all animals in certain areas of Finnish forests. In Finland there are about 60 species of ants that have been observed. They have been divided into four sub-groups, which are Myrmicinae, Formicinae, Ponerinae and Dolichoderinae. In Finland there are close to 300 species of ground beetles (Carabidae), which are divided into dozens of different families. The species, to a great extent, consist mostly of predatory insects that prey on microbes in field layers, but a part of them are specialized in feeding on flora. Ground beetles are usually divided into three groups according to their choice of habitat: Species that favour open biotopes, species that favour forests, and generalist species that can thrive in a variety of environments. Ground beetles also reflect changes in their living environment, and possibly they can be significant as socalled bio-indicators. Pitfall traps were used as the method of research. The preservative fluid used was ethanol (50%) with dishwashing liquid to remove surface tension. The points were located in various different biotopes in fields, meadows and forests. The data collected was defined as a minimum for the family level of Ground beetles and for ants to the species or species pairs. The species of Ground

Eurajoki Olkiluoto study on species of ground beetles and ants 2008

Energy Technology Data Exchange (ETDEWEB)

Santaharju, J.; Helminen, S.-L.; Yrjoelae, R. (Environmental Research Yrjoelae Ltd, Helsinki (Finland))

2009-02-15

The species of ants and Ground beetles at Olkiluoto in Eurajoki were studied in the summer of 2008 during two trapping periods: in June and August. The research goal was to clarify the species on Olkiluoto island of the earlier mentioned groups, at least at the family level, and to collect samples for further examination by Posiva. The trapping areas were selected at Olkiluoto in Posiva test monitoring sectors, a part of the trapping areas was the same as the earlier study. Species of ants, depending on their particular species, are a very dominating group of insects. The ants are the most important predators, scavengers and soil movers in Finnish forests. It looks as if the biomass of ants may be more than 10% of the biomass of all animals in certain areas of Finnish forests. In Finland there are about 60 species of ants that have been observed. They have been divided into four sub-groups, which are Myrmicinae, Formicinae, Ponerinae and Dolichoderinae. In Finland there are close to 300 species of ground beetles (Carabidae), which are divided into dozens of different families. The species, to a great extent, consist mostly of predatory insects that prey on microbes in field layers, but a part of them are specialized in feeding on flora. Ground beetles are usually divided into three groups according to their choice of habitat: Species that favour open biotopes, species that favour forests, and generalist species that can thrive in a variety of environments. Ground beetles also reflect changes in their living environment, and possibly they can be significant as socalled bio-indicators. Pitfall traps were used as the method of research. The preservative fluid used was ethanol (50%) with dishwashing liquid to remove surface tension. The points were located in various different biotopes in fields, meadows and forests. The data collected was defined as a minimum for the family level of Ground beetles and for ants to the species or species pairs. The species of Ground

Fracture calcites at Olkiluoto. Evidence from quaternary infills for palaeohydrogeology

International Nuclear Information System (INIS)

Gehoer, S.; Kaerki, A.; Taikina-aho, O.; Karhu, J.; Loefman, J.; Pitkaenen, P.; Ruotsalainen, P.

2002-02-01

Recently formed secondary minerals, predominantly calcite, occur in varying amounts as fracture infills, and the calcite types, their chemical compositions and isotope ratios reflect the compositions and physicochemical factors of the groundwater system in which they were formed. Fluid inclusions trapped in calcites give direct evidence of trapping temperatures and past salinities and of the chemical compositions of the palaeo fluids. A wide range of mineralogical and geochemical examinations were carried out within the EQUIP project to examine features of this kind. The fracture calcites at the Olkiluoto site are of various origins and represent several textural types. The exact number of calcite-producing events is unknown, but the duration of the period that was appropriate for the precipitation of low temperature calcite is estimated to have exceeded 1000 Ma. Thus the number of genetically related calcite units is assumed to be considerable. This study was focused on the petrogenesis of calcites crystallized in fractures of high water conductivity during the latest stages of geological evolution. The majority of these late stage calcites form physically homogeneous, scaly layers, and in a few cases thin layers composed of idiomorphic crystals. Chemically these are almost stoichiometric calcites (CaCO 3 ). The MnO content may exceed 1%, while the amounts of other elements present are minor, although the trace element concentrations, particularly those of large ionic trace elements, can be used as distinguishing features for the recognition of individual precipitates representing different calcite generations. Evidence from fluid inclusions, or more correctly from the absence of these in the late stage calcites, can be interpreted as an indication of slow rates of crystallization under cool conditions. Many chemical variables, e.g. oxygen isotope ratios, demonstrate an equilibrium between the latest calcites and water similar to the present groundwater. Older

Fracture calcites at Olkiluoto. Evidence from quaternary infills for palaeohydrogeology

Energy Technology Data Exchange (ETDEWEB)

Gehoer, S.; Kaerki, A.; Taikina-aho, O. [Kivitieto Oy (Finland); Karhu, J. [Helsinki Univ. (Finland); Loefman, J. [VTT Processes, Espoo (Finland); Pitkaenen, P. [VTT Building and Transport, Espoo (Finland); Ruotsalainen, P. [TUKES, Helsinki (Finland)

2002-02-01

Recently formed secondary minerals, predominantly calcite, occur in varying amounts as fracture infills, and the calcite types, their chemical compositions and isotope ratios reflect the compositions and physicochemical factors of the groundwater system in which they were formed. Fluid inclusions trapped in calcites give direct evidence of trapping temperatures and past salinities and of the chemical compositions of the palaeo fluids. A wide range of mineralogical and geochemical examinations were carried out within the EQUIP project to examine features of this kind. The fracture calcites at the Olkiluoto site are of various origins and represent several textural types. The exact number of calcite-producing events is unknown, but the duration of the period that was appropriate for the precipitation of low temperature calcite is estimated to have exceeded 1000 Ma. Thus the number of genetically related calcite units is assumed to be considerable. This study was focused on the petrogenesis of calcites crystallized in fractures of high water conductivity during the latest stages of geological evolution. The majority of these late stage calcites form physically homogeneous, scaly layers, and in a few cases thin layers composed of idiomorphic crystals. Chemically these are almost stoichiometric calcites (CaCO{sub 3}). The MnO content may exceed 1%, while the amounts of other elements present are minor, although the trace element concentrations, particularly those of large ionic trace elements, can be used as distinguishing features for the recognition of individual precipitates representing different calcite generations. Evidence from fluid inclusions, or more correctly from the absence of these in the late stage calcites, can be interpreted as an indication of slow rates of crystallization under cool conditions. Many chemical variables, e.g. oxygen isotope ratios, demonstrate an equilibrium between the latest calcites and water similar to the present groundwater. Older

Disposal of spent fuel in Olkiluoto bedrock. Programme for research, development and technical design for the pre-construction phase

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-12-01

The spent fuel from the nuclear power plants at Olkiluoto and Loviisa will be disposed of in Finnish bedrock. Posiva aims at starting the construction of the disposal facility in the 2010's and the actual disposal operations in 2020. In May 1999 Posiva submitted an application for the so-called Decision-in-Principle (DiP) on the facility to the Finnish Government. According to the application the repository would be based on a KBS-3 type concept and sited at Olkiluoto. The application was approved by the Government in December 2000 and will go next to the Parliament for final approval. However, Posiva has already started the planning for the next programme phase on the assumption that a positive decision will be made. The purpose of the present document is to describe the objectives and major items of research, development, technical planning and design work for the period preceding the construction license. According to the current official guidelines Posiva should prepare for submitting the application for the license in 2010. For the technical development and design work the main target for the starting programme phase is to reach the maturity of design and technical plans that allows the specification of work packages for bid calls and gives sufficient confidence in the technical feasibility of planned operations at the encapsulation facility and in the repository. The main objectives for the complementary characterisation work at Olkiluoto consist of the verification of the present conclusions on site suitability, the definition and identification of suitable rock volumes for repository space and the characterisation of the target host rock for repository design, safety assessment and planning of construction work. The technical design and demonstration work together with the results of complementary site characterisation will provide the basis of the safety case prepared as the support for the construction license application. An integrated safety

Disposal of spent fuel in Olkiluoto bedrock. Programme for research, development and technical design for the pre-construction phase

International Nuclear Information System (INIS)

2000-12-01

The spent fuel from the nuclear power plants at Olkiluoto and Loviisa will be disposed of in Finnish bedrock. Posiva aims at starting the construction of the disposal facility in the 2010's and the actual disposal operations in 2020. In May 1999 Posiva submitted an application for the so-called Decision-in-Principle (DiP) on the facility to the Finnish Government. According to the application the repository would be based on a KBS-3 type concept and sited at Olkiluoto. The application was approved by the Government in December 2000 and will go next to the Parliament for final approval. However, Posiva has already started the planning for the next programme phase on the assumption that a positive decision will be made. The purpose of the present document is to describe the objectives and major items of research, development, technical planning and design work for the period preceding the construction license. According to the current official guidelines Posiva should prepare for submitting the application for the license in 2010. For the technical development and design work the main target for the starting programme phase is to reach the maturity of design and technical plans that allows the specification of work packages for bid calls and gives sufficient confidence in the technical feasibility of planned operations at the encapsulation facility and in the repository. The main objectives for the complementary characterisation work at Olkiluoto consist of the verification of the present conclusions on site suitability, the definition and identification of suitable rock volumes for repository space and the characterisation of the target host rock for repository design, safety assessment and planning of construction work. The technical design and demonstration work together with the results of complementary site characterisation will provide the basis of the safety case prepared as the support for the construction license application. An integrated safety assessment

Strength and strain anisotropy of olkiluoto mica gneiss

International Nuclear Information System (INIS)

Hakala, M.; Kuula, H.; Hudson, J.

2006-10-01

An anisotropy in the elastic moduli values of intact rock with a ratio of more than 1.3∼1.5 has been reported to have an effect on the calculated magnitudes and orientations of the in situ principal stress components as measured by the overcoring method. Work related to the on-going site investigation for a deep radioactive waste repository at the Olkiluoto site in Western Finland has shown that the migmatic mica gneiss is anisotropic which could therefore affect the interpretation of overcoring stress measurement results. This paper includes a summary of the theory of anisotropy concerning the intact rock moduli via the strain compliance matrix, a description of the core sample testing methods, and interpretation of results for the migmatic mica gneiss from two site investigation boreholes. In this case study, 19 specimens were tested and the results showed a modulus anisotropy of about 1.4. Because such anisotropy is high enough to produce significant errors in the estimation of the in situ principal stresses, it is recommended to take this into account in the interpretation of the stress measurement results, both in the context of the current work in Finland and in other projects where similar anisotropy is encountered. (orig.)

Geological model of the Olkiluoto site Version O

International Nuclear Information System (INIS)

Paulamaeki, S.; Paananen, M.; Gehoer, S.

2006-05-01

The geological model of the Olkiluoto site consists of four submodels: the lithological model, the ductile deformation model, the brittle deformation model and the alteration model. The lithological model gives properties of definite rock units that can be defined on the basis the migmatite structures, textures and modal compositions. The ductile deformation model describes and models the products of polyphase ductile deformation, which enables to define the dimensions and geometrical properties of individual lithological units determined in the lithological model. The brittle deformation model describes the products of multiple phases of brittle deformation. The alteration model describes the types, occurrence and the effects of the hydrothermal alteration. The rocks of Olkiluoto can be divided into two major classes: (1) supracrustal high-grade metamorphic rocks including various migmatitic gneisses, tonalitic-granodioriticgranitic gneisses, mica gneisses, quartz gneisses and mafic gneisses, and (2) igneous rocks including pegmatitic granites and diabase dykes. The migmatitic gneisses can further be divided into three subgroups in terms of the type of migmatite structure: veined gneisses, stromatic gneisses and diatexitic gneisses. On the basis of refolding and crosscutting relationships, the metamorphic supracrustal rocks have been subject to polyphased ductile deformation, including five stages. In 3D modelling of the lithological units, an assumption has been made, on the basis of measurements in outcrops, investigation trenches and drill cores, that the pervasive, composite foliation produced as a result a polyphase ductile deformation has a rather constant attitude in the ONKALO area. Consequently, the strike and dip of the foliation has been used as a tool, through which the lithologies have been correlated between the drillholes and from the surface to the drillholes. The bedrock in the Olkiluoto site has been subject to extensive hydrothermal alteration

Evaluation of the radioactive waste characterisation at the Olkiluoto nuclear power plant

International Nuclear Information System (INIS)

Kekki, T.; Titta, A.

2000-03-01

The aim of this study is to evaluate the physical, chemical and radiological characterisation, handling and documentation of the radioactive waste packages to be disposed of in the VLJ-repository at the Olkiluoto NPP. A comparison with the current practices in Europe, based on information from Sweden, Spain and Czech Republic, is made. The report presents recommendations for STUK to harmonise the LILW waste management practises in Finland with those in Europe. (orig.)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Terrain and ecosystems development modelling in the biosphere assessment BSA-2012

International Nuclear Information System (INIS)

2013-12-01

This report is one of the four supporting reports for the three main biosphere reports in the safety case for the disposal of spent nuclear fuel at Olkiluoto, 'TURVA-2012'. The focus of this report is to detail the scenario analysis of terrain and ecosystems development at the Olkiluoto repository site within a time frame of 10 000 years, whereas the input data to this modelling is detailed in the Data Basis report. The results are used further especially in the surface and near-surface hydrological modelling and in the biosphere radionuclide transport and dose modelling, both part of the biosphere assessment 'BSA-2012' feeding into the safety case. Based on the results of the 18 cases simulated in the scenario analysis, it can be outlined that the most significant differences in respect of the dose implications of the repository arise from the inputs and settings affecting the rate of coastline retreat (i.e. land uplift and sea level) and determining whether there are croplands or not in the area. (orig.)

Results of monitoring at Olkiluoto in 2008. Foreign Materials

International Nuclear Information System (INIS)

Juhola, P.

2009-08-01

This report focuses on foreign materials introduced to ONKALO. These foreign materials are not part of the multi-barrier system or the natural environment. All the allowed materials introduced to ONKALO are included in the material handbook. All materials used in ONKALO 2008 are listed in this report. During 2008 the ONKALO access tunnel was excavated from chainage 2581 to chainage 3307 and the total excavated volume in 2008 was 38812 m 3 . During 2004 to 2008 the total excavated volume was 161060 m 3 . This report also summaries the total amount of foreign materials used in ONKALO since 2004. All waters used during the excavation of ONKALO are pumped up to the surface into a sedimentation pool. In 2008 water samples were taken from sedimentation pool and from the outlet ditch. The chemistry of these waters can predict us how the use of foreign materials has affected to the baseline groundwater chemistry. (orig.)

Results of monitoring at Olkiluoto in 2009. Foreign materials

International Nuclear Information System (INIS)

Kasa, S.

2011-02-01

This report focuses on foreign materials introduced to ONKALO. These foreign materials are not part of the engineered multi-barrier system or the natural environment. All the allowed materials introduced to ONKALO are included in the material handbook. All materials used in ONKALO 2009 are listed in this report. During 2009 the ONKALO access tunnel was excavated from the chainage of 3297 to the chainage of 4059 and the total excavated volume in 2009 was 36778 m 3 . During the years 2004 and 2009 the total excavated volume was 197838 m 3 . This report also summaries the total amount of foreign materials used in ONKALO since 2004. All waters used during the excavation of ONKALO have been pumped up to the surface into a sedimentation pool. In 2009 water samples were taken from sedimentation pool, from the end of the discharge tube and from the outlet ditch. The chemistry of these waters can indicate us how the foreign materials have effected on the undisturbed groundwater chemistry. (orig.)

Results of monitoring at Olkiluoto in 2011. Foreign materials

International Nuclear Information System (INIS)

Salo, V.

2013-06-01

This report focuses on foreign materials introduced to ONKALO. These foreign materials are not part of the engineered multi-barrier system or the natural environment. All the allowed materials introduced to ONKALO are included in the material handbook. All materials used in ONKALO 2011 are listed in this report. During 2011 the ONKALO access tunnel was excavated from the chainage of 4570 to the chainage of 4913 and the total excavated volume in 2011 was 77750 m 3 . During the years from 2004 to 2011 the total excavated volume was 305240 m 3 . This report also summaries the total amount of foreign materials used in ONKALO since 2004. All waters used during the excavation of ONKALO have been pumped up to the surface into a sedimentation pool. In 2011 water samples were taken from sedimentation pool and from the outlet ditch. The chemistry of these waters can indicate us how the foreign materials have effected on the undisturbed groundwater chemistry. (orig.)

Results of monitoring at Olkiluoto in 2010. Foreign materials

International Nuclear Information System (INIS)

Salo, V.

2012-11-01

This report focuses on foreign materials introduced to ONKALO. These foreign materials are not part of the engineered multi-barrier system or the natural environment. All the allowed materials introduced to ONKALO are included in the material handbook. All materials used in ONKALO 2010 are listed in this report. During 2010 the ONKALO access tunnel was excavated from the chainage of 4059 to the chainage of 4570 and the total excavated volume in 2010 was 29652 m 3 . During the years from 2004 to 2010 the total excavated volume was 227490 m 3 . This report also summaries the total amount of foreign materials used in ONKALO since 2004. All waters used during the excavation of ONKALO have been pumped up to the surface into a sedimentation pool. In 2010 water samples were taken from sedimentation pool and from the outlet ditch. The chemistry of these waters can indicate us how the foreign materials have effected on the undisturbed groundwater chemistry. (orig.)

Slug-Tests in PP- and PVP-holes at Olkiluoto in 2007

International Nuclear Information System (INIS)

Keskitalo, K.

2008-05-01

As part of the program for the final disposal of the nuclear fuel waste, Posiva Oy investigates the hydrological conditions at the Olkiluoto island. The hydraulic conductivity in the shallow holes OL-PP9, OL-PP36, OL-PP39, OL-PVP3A, OL-PVP3B, OL-PVP4A, OL-PVP4B, OL-PVP6A, OL-PVP6B, OL-PVP7A, OL-PVP8A, OL-PVP8B, OL-PVP9A, OL-PVP9B, OL-PVP10A, OL-PVP10B, OL-PVP11, OL-PVP12, OL-PVP13, OL-PVP14, OL-PVP17, OL-PVP18A, OL-PVP18B, OL-PVP19 and OL-PVP20 was measured in summer 2007. The length of PP-holes varies between 12 and 15 m, and the test sections (1 m) are located in the bedrock. PVP-tubes have an average length between 3 - 9 m up to 17 m, and the test sections (mostly 2 m) are located in the overburden. The measurements were done using the slug-test technique. In the slug-test, the hydraulic head in the borehole is abruptly changed either by pouring water into the borehole or by lowering the pressure sensor. The conductivity is interpreted based on the recovery of the water level. This report presents the field measurements and their interpretation. The interpretation has been done using the Hvorslev's method, and for reference, conductivity has also been calculated according to Thiem's equation. According to the results, hydraulic conductivity in PP-holes ranges from 10-9 m/s to 10-6 m/s and in PVP-tubes from 10-8 m/s to 10-4 m/s. The range is similar as observed in measurements of years 2002, 2004, 2005 and 2006. In general, the results are consistent with the results obtained in earlier measurements. Some exceptions exist in OL-PVP6B, where the conductivity is higher than in the earlier measurements. In OL-PVP14, there seems to be a lowering trend of the conductivity. In OL-PP9, the conductivity in test section 5.3 - 6.3 m in 2007 was about one order of magnitude lower than in 2005 but the results from 2007, 2006, and 2002 correlate well in that section. Also, the results agree with hydraulic conductivity interpreted from the pre-pumping done in connection with

Meteorological data and update of climate statistics of Olkiluoto 2005 - 2006

International Nuclear Information System (INIS)

Ikonen, A.T.K.

2007-10-01

In this working report the data of some routine field observations of Posiva Oy and automatic measurements of the Olkiluoto nuclear power plant weather station owned and operated by Teollisuuden Voima Oy is published for further reference. The data reported here covers observations in 2005-2006. First, a concise description of data acquisition methods and handling is provided. Thereafter the actual data is presented in the appendices. Weather measurements (e.g. temperature, wind speed and direction, humidity) and snow and ground frost observations are reported. (orig.)

Rock mass seismic imaging around the ONKALO tunnel, Olkiluoto 2007

International Nuclear Information System (INIS)

Cosma, C.; Cozma, M.; Balu, L.; Enescu, N.

2008-11-01

Posiva Oy prepares for disposal of spent nuclear fuel in bedrock focusing in Olkiluoto, Eurajoki. This is in accordance of the application filed in 1999, the Decision-in-Principle of the State Council in 2000, and ratification by the Parliament in 2001. Vibrometric Oy has performed a tunnel seismic survey in ONKALO access tunnel on a 100 m line in December 2007. Tunnel length (chainage) was 1720 - 1820 m (vertical depth 170 - 180 m). Measurement applied 120 source positions at 1 m spacing, and on the both ends at 4 m spacing. Electromechanical Vibsist-20 tool was used as the source. Hammer produced 15.36 s sweeps. Signal was recorded with 2-component geophone assemblies, installed in 400 mm long, 45 mm drillholes in the tunnel wall. Sweeps were recorded with Summit II seismograph and decoded to seismic traces. Also percussion drill rig, which is used in drilling the blasting holes in tunnel excavation, was tested from a 100-m distance as a seismic source. Signal is equally good as from actual seismic source, and may be applied later on for production. Obtained seismic results were processed with tomographic reconstruction of the first arrivals to P and S wave refraction tomograms, and to tomograms of Young's modulus and Shear Modulus. The obtained values correspond the typical levels known from Olkiluoto. There are indications of lower velocity near tunnel wall, but resolution is not adequate for further interpretation. Some variation of velocity is detected in the rock mass. Seismic data was also processed with normal reflection profile interpretation and migrated. As a result there was obtained reflection images to a 100-m distance from the tunnel. Several reflecting events were observed in the rock mass. Features making an angle of 30 deg or more with tunnel axis can be imaged from distances of tens of metres. Vertical fractures perpendicular to tunnel can be imaged only near the tunnel. Gently dipping features can be imaged below and above. Images are 2D, i

Laboratory measurements of the coefficient of thermal expansion of Olkiluoto drill core samples

International Nuclear Information System (INIS)

Aakesson, U.

2012-04-01

The coefficient of thermal expansion and the wet density has been determined on 22 specimens from the ONKALO drillholes ONK-PP167, ONK-PP199, ONK-PP224, ONK-PP225 and ONK-PP226, Olkiluoto, Finland. The coefficient of thermal expansion has been determined in the temperature interval 20-60 deg C. The results indicated that the thermal expansion was almost linear, and the coefficient of thermal expansion for the investigated specimens range between 3.2 and 14.4 x 10 -6 mm/mm deg C, and the wet density between 2,610 and 2,820 kg/m 3 . The granite pegmatite has slightly lower coefficient of thermal expansion and wet density than gneissic rocks. (orig.)

Modelling end-glacial earthquakes at Olkiluoto. Expansion of the 2010 study

Energy Technology Data Exchange (ETDEWEB)

Faelth, B.; Hoekmark, H. [Clay Technology AB, Lund (Sweden)

2012-02-15

The present report is an extension of Posiva working report 2011-13: 'Modelling end-glacial earthquakes at Olkiluoto'. The modelling methodology and most parameter values are identical to those used in that report. The main objective is the same: to obtain conservative estimates of fracture shear displacements induced by end-glacial earthquakes occurring on verified deformation zones at the Olkiluoto site. The remotely activated rock fractures (with their fracture centres positioned at different distances around the potential earthquake fault being considered) are called 'target fractures'. As in the previous report, all target fractures were assumed to be perfectly planar and circular with a radius of 75 m. Compared to the previous study, the result catalogue is more complete. One additional deformation zone (i.e. potential earthquake fault) has been included (BFZ039), whereas one deformation zone that appeared to produce only insignificant target fracture disturbances (BFZ214) is omitted. For each of the three zones considered here (BFZ021, BFZ039, and BFZ100), four models, each with a different orientation of the target fractures surrounding the fault, are analysed. Three of these four sets were included in the previous report, however not as systematically as here where each of the four fracture orientations is tried in all fracture positions. As in the previous study, seismic moments and moment magnitudes are as high as reasonably possible, given the sizes and orientations of the zones, i.e., the earthquakes release the largest possible amount of strain energy. The strain energy release is restricted only by a low residual fault shear strength applied to suppress post-rupture fault oscillations. Moment magnitudes are: 5.8 (BFZ021), 3.9 (BFZ039) and 4.3 (BFZ100). For the BFZ100 model, the sensitivity of the results to variations in fracture shear strength is checked. The BFZ021 and BFZ100 models are analyzed for two additional in situ stress

Slug-tests in PP- and PVP-holes at Olkiluoto in 2010

International Nuclear Information System (INIS)

Hinkkanen, H.

2011-07-01

As part of the program for the final disposal of the nuclear fuel waste, Posiva Oy investigates the hydrological conditions at the Olkiluoto Island. The hydraulic conductivity in the shallow holes OL-PP36, OL-PP39, OL-PVP4A, OL-PVP4B, OL-PVP6A, OL-PVP6B, OL-PVP7A, OL-PVP8A, OL-PVP8B, OL-PVP9A OL-PVP9B, OL-PVP9C, OL-PVP10A, OL-PVP10B, OL-PVP11, OL-PVP12, OLPVP14, OL-PVP17, OL-PVP19, OL-PVP20, OL-PVP30, OL-PVP31A, OL-PVP31B, OL-PVP32, OL-PVP33, OL-PVP34A, OL-PVP34B, OL-HP1, OL-HP2, OL-HP3 and OL-HP4 was measured in summer 2010. The length of PP-holes was between 12 and 14 m, and the test sections (1 m) are located in the bedrock. PVP-tubes have an average length between 3..11 m up to c. 17 m, and the test sections (mostly 2 m) are located in the overburden. The measurements were carried out using the slug-test technique with renewed equipment. In the slug-test, the hydraulic head in the borehole is abruptly changed either by pouring water into the borehole or by lowering the pressure sensor. The hydraulic conductivity is interpreted from the recovery of the water level. This report presents the field measurements and their interpretation. The interpretation has been done using the Hvorslev's method, and for reference, conductivity has also been calculated according to Thiem's equation. According to the results, hydraulic conductivity in PP-holes ranges from 10-9 m/s to 10-6 m/s and in PVP-tubes from 10-8 m/s to 10-4 m/s. The observed range is quite similar as in the previous measurements in 2002 and 2004-2009. In general, the results are consistent with the results obtained in earlier measurements. In OL-PVP14, the earlier observed lowering trend of the conductivity seems to have stabilized. Also, the results agree relatively well with hydraulic conductivity interpreted from the pre-pumping done in connection with the groundwater sampling. (orig.)

Patterns in groundwater chemistry resulting from groundwater flow

Science.gov (United States)

Stuyfzand, Pieter J.

Groundwater flow influences hydrochemical patterns because flow reduces mixing by diffusion, carries the chemical imprints of biological and anthropogenic changes in the recharge area, and leaches the aquifer system. Global patterns are mainly dictated by differences in the flux of meteoric water passing through the subsoil. Within individual hydrosomes (water bodies with a specific origin), the following prograde evolution lines (facies sequence) normally develop in the direction of groundwater flow: from strong to no fluctuations in water quality, from polluted to unpolluted, from acidic to basic, from oxic to anoxic-methanogenic, from no to significant base exchange, and from fresh to brackish. This is demonstrated for fresh coastal-dune groundwater in the Netherlands. In this hydrosome, the leaching of calcium carbonate as much as 15m and of adsorbed marine cations (Na+, K+, and Mg2+) as much as 2500m in the flow direction is shown to correspond with about 5000yr of flushing since the beach barrier with dunes developed. Recharge focus areas in the dunes are evidenced by groundwater displaying a lower prograde quality evolution than the surrounding dune groundwater. Artificially recharged Rhine River water in the dunes provides distinct hydrochemical patterns, which display groundwater flow, mixing, and groundwater ages. Résumé Les écoulements souterrains influencent les différents types hydrochimiques, parce que l'écoulement réduit le mélange par diffusion, porte les marques chimiques de changements biologiques et anthropiques dans la zone d'alimentation et lessive le système aquifère. Ces types dans leur ensemble sont surtout déterminés par des différences dans le flux d'eau météorique traversant le sous-sol. Dans les "hydrosomes" (masses d'eau d'origine déterminée), les lignes marquant une évolution prograde (séquence de faciès) se développent normalement dans la direction de l'écoulement souterrain : depuis des fluctuations fortes de la

Tomographic imaging of 12 fracture samples selected from Olkiluoto deep drillholes

International Nuclear Information System (INIS)

Kuva, J.; Voutilainen, M.; Timonen, J.; Aaltonen, I.

2010-06-01

Rock samples from Olkiluoto were imaged with X-ray tomography to analyze distributions of mineral components and alteration of rock around different fracture types. Twelve samples were analyzed, which contained three types of fractures, and each sample was scanned with two different resolutions. Three dimensional reconstructions of the samples with four or five distinct mineral components displayed changes in the mineral distribution around previously water conducting fractures, which extended to a depth of several millimeters away from fracture surfaces. In addition, structure of fracture filling minerals is depicted. (orig.)

Safety Assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto

International Nuclear Information System (INIS)

Smith, P.; Neall, F.; Snellman, M.; Pastina, B.; Hjerpe, T.; Nordman, H.; Johnson, L.

2007-12-01

The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RD and D) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. This safety assessment is summarised in the present report. The scientific basis of the safety assessment includes around 30 years of scientific R and D and technical development in the Swedish and Finnish KBS-3V programmes. Much of this scientific basis is directly applicable to KBS-3H. This has allowed the KBS-3H safety studies to focus on those issues that are unique to this design alternative, identified in a systematic difference analysis of KBS-3H and KBS-3V. This difference analysis has shown that the key differences in the evolution and performance of KBS-3H and KBS-3V relate mainly to the engineered barrier system and to the impact of local variations in the rate of groundwater inflow on buffer saturation along the KBS-3H deposition drifts. No features or processes specific to KBS-3H have been identified that could lead to a loss or substantial degradation of the safety functions of the engineered barriers over a million year time frame. Radionuclide release from the repository near field in the event of

World-class outage performance of the Olkiluoto nuclear power plant

International Nuclear Information System (INIS)

Paavola, M.

1998-01-01

The production of the Olkiluoto power plant units covered 17% of the electricity consumption in Finland in 1997; the total share of nuclear energy was 27% of the electricity consumed in the country. Based on Finnish experience, nuclear energy is a safe, environmentally friendly and economic way to produce electricity provided that the plants and their personnel are well taken care of. TVO's policy is to keep the plant units in good condition and technically modern. This requires continuous investments in the plant. In maintenance, attention is paid to monitoring the condition of the plant and to preventive maintenance aiming at avoiding disturbances in production. TVO has chosen continuous development as the operational line develops the plant by annual investments and performs the necessary modifications during planned annual outages trying to avoid long production interruptions. The load factors of the Olkiluoto nuclear power plant have been high. The average load factor during the last decade was over 93%. The most significant single factor in the production deficits is the amount or electricity, which has not been produced because of the annual outages. Due to this, special attention has been paid to the performance of the annual outages. TVO aims at continuous development of the annual outage procedure. A centralized task management system makes it possible to perform simultaneously more tasks than before. The company has also invested in equipment and systems, which ease and speed up servicing. Normal outage length varies between 10 and 16 days. By keeping the plant units as modern as possible and in good condition we facilitate reaching TVO's target, which is also stated in TVO's slogan 'always 40 years lifetime'. (author)

Geological discrete fracture network model for the Olkiluoto site, Eurajoki, Finland. Version 2.0

International Nuclear Information System (INIS)

Fox, A.; Forchhammer, K.; Pettersson, A.; La Pointe, P.; Lim, D-H.

2012-06-01

This report describes the methods, analyses, and conclusions of the modeling team in the production of the 2010 revision to the geological discrete fracture network (DFN) model for the Olkiluoto Site in Finland. The geological DFN is a statistical model for stochastically simulating rock fractures and minor faults at a scale ranging from approximately 0.05 m to approximately 565m; deformation zones are expressly excluded from the DFN model. The DFN model is presented as a series of tables summarizing probability distributions for several parameters necessary for fracture modeling: fracture orientation, fracture size, fracture intensity, and associated spatial constraints. The geological DFN is built from data collected during site characterization (SC) activities at Olkiluoto, which is selected to function as a final deep geological repository for spent fuel and nuclear waste from the Finnish nuclear power program. Data used in the DFN analyses include fracture maps from surface outcrops and trenches, geological and structural data from cored drillholes, and fracture information collected during the construction of the main tunnels and shafts at the ONKALO laboratory. Unlike the initial geological DFN, which was focused on the vicinity of the ONKALO tunnel, the 2010 revisions present a model parameterization for the entire island. Fracture domains are based on the tectonic subdivisions at the site (northern, central, and southern tectonic units) presented in the Geological Site Model (GSM), and are further subdivided along the intersection of major brittle-ductile zones. The rock volume at Olkiluoto is dominated by three distinct fracture sets: subhorizontally-dipping fractures striking north-northeast and dipping to the east that is subparallel to the mean bedrock foliation direction, a subvertically-dipping fracture set striking roughly north-south, and a subvertically-dipping fracture set striking approximately east-west. The subhorizontally-dipping fractures

Geological discrete fracture network model for the Olkiluoto site, Eurajoki, Finland. Version 2.0

Energy Technology Data Exchange (ETDEWEB)

Fox, A.; Forchhammer, K.; Pettersson, A. [Golder Associates AB, Stockholm (Sweden); La Pointe, P.; Lim, D-H. [Golder Associates Inc. (Finland)

2012-06-15

This report describes the methods, analyses, and conclusions of the modeling team in the production of the 2010 revision to the geological discrete fracture network (DFN) model for the Olkiluoto Site in Finland. The geological DFN is a statistical model for stochastically simulating rock fractures and minor faults at a scale ranging from approximately 0.05 m to approximately 565m; deformation zones are expressly excluded from the DFN model. The DFN model is presented as a series of tables summarizing probability distributions for several parameters necessary for fracture modeling: fracture orientation, fracture size, fracture intensity, and associated spatial constraints. The geological DFN is built from data collected during site characterization (SC) activities at Olkiluoto, which is selected to function as a final deep geological repository for spent fuel and nuclear waste from the Finnish nuclear power program. Data used in the DFN analyses include fracture maps from surface outcrops and trenches, geological and structural data from cored drillholes, and fracture information collected during the construction of the main tunnels and shafts at the ONKALO laboratory. Unlike the initial geological DFN, which was focused on the vicinity of the ONKALO tunnel, the 2010 revisions present a model parameterization for the entire island. Fracture domains are based on the tectonic subdivisions at the site (northern, central, and southern tectonic units) presented in the Geological Site Model (GSM), and are further subdivided along the intersection of major brittle-ductile zones. The rock volume at Olkiluoto is dominated by three distinct fracture sets: subhorizontally-dipping fractures striking north-northeast and dipping to the east that is subparallel to the mean bedrock foliation direction, a subvertically-dipping fracture set striking roughly north-south, and a subvertically-dipping fracture set striking approximately east-west. The subhorizontally-dipping fractures

Stable elements and radionuclides in shoreline alder stands at Olkiluoto in 2005

International Nuclear Information System (INIS)

Roivainen, P.

2006-08-01

In Finland, the final disposal of spent nuclear fuel from Finnish nuclear power plants is to take place in a repository, which will be built in Olkiluoto bedrock. According to the current plans, operation of the facility will start in 2020. Before this, a safety case has to be drawn up to substantiate the safety of the final disposal solution. The drawing up of the safety case also involves an assessment of impact on organisms other than human. Several radionuclides have a stable chemical analogue. Chemical analogues often display similar behaviour in the forest ecosystem. For this reason, information about radionuclides can also be obtained by studying stable elements. The purpose of this thesis was to study the migration of elements, radionuclides in particular, in the food webs of the Olkiluoto forest ecosystem. The objective was to produce concentration ratios between the various sub-components of the forest ecosystem. These ratios can be utilised in modelling. Three alder stands on the shores of Olkiluoto were used as monitoring plots. Littoral alder stands are an important biotope in terms of a recipient of the potential radionuclide contamination from the repository. Yet, research on littoral alder stands has so far been quite limited. From all the monitoring plots, a sample was taken of humus, mineral soil, understorey, plant roots and forest litter. Small mammals and earthworms were also to be caught from the monitoring plots, but no earthworms could be caught in any of the areas. All the collected samples were analysed for element concentrations using the ICP-AES method. Soil and plant samples were also analysed with a gamma spectrometer for activity concentrations of gamma active radionuclides. Activity concentrations of Cs-137 and K-40 could be determined in all soil and plant samples. The highest activity concentration of Cs-137 was found in humus, and the lowest in mineral soil. The activity concentration of K-40 was at its highest in mineral soil and

Statistical Analysis and Modelling of Olkiluoto Structures

International Nuclear Information System (INIS)

Hellae, P.; Vaittinen, T.; Saksa, P.; Nummela, J.

2004-11-01

Posiva Oy is carrying out investigations for the disposal of the spent nuclear fuel at the Olkiluoto site in SW Finland. The investigations have focused on the central part of the island. The layout design of the entire repository requires characterization of notably larger areas and must rely at least at the current stage on borehole information from a rather sparse network and on the geophysical soundings providing information outside and between the holes. In this work, the structural data according to the current version of the Olkiluoto bedrock model is analyzed. The bedrock model relies much on the borehole data although results of the seismic surveys and, for example, pumping tests are used in determining the orientation and continuation of the structures. Especially in the analysis, questions related to the frequency of structures and size of the structures are discussed. The structures observed in the boreholes are mainly dipping gently to the southeast. About 9 % of the sample length belongs to structures. The proportion is higher in the upper parts of the rock. The number of fracture and crushed zones seems not to depend greatly on the depth, whereas the hydraulic features concentrate on the depth range above -100 m. Below level -300 m, the hydraulic conductivity occurs in connection of fractured zones. Especially the hydraulic features, but also fracture and crushed zones often occur in groups. The frequency of the structure (area of structures per total volume) is estimated to be of the order of 1/100m. The size of the local structures was estimated by calculating the intersection of the zone to the nearest borehole where the zone has not been detected. Stochastic models using the Fracman software by Golder Associates were generated based on the bedrock model data complemented with the magnetic ground survey data. The seismic surveys (from boreholes KR5, KR13, KR14, and KR19) were used as alternative input data. The generated models were tested by

Operating experience feedback program at Olkiluoto NPP

International Nuclear Information System (INIS)

Kosonen, Mikko

2002-01-01

Recent review and development of the operating experience feedback program will be described. The development of the program has been based on several reviews by outside organizations. Main conclusions from these review reports and from the self assessment of safety performance, safety problems and safety culture on the basis of the operational events made by ASSET-method will be described. An approach to gather and analyze small events - so-called near misses - will be described. The operating experience program has been divided into internal and external operating experience. ASSET-methodology and a computer program assisting the analysis are used for the internal operating experience events. Noteworthy incidents occurred during outage are analyzed also by ASSET-method. Screening and pre analysis of the external operating experience relies on co-operation with ERFATOM, an organization of Nordic utilities for the exchange of nuclear industry experience. A short presentation on the performance of the Olkiluoto units will conclude the presentation. (author)

Development of SVAT model for computing water and energy balance of the forest intensive monitoring plots on Olkiluoto island

International Nuclear Information System (INIS)

Karvonen, T.

2009-06-01

This Working Report presents the main results of SVAT (Soil-Vegetation-Atmosphere- Transfer) model that was developed to analyze the different water and energy balance components of the Forest Intensive monitoring plots (FIP) on Olkiluoto Island. The Olkiluoto SVAT model divides above ground vegetation in two layers: overstorey (trees) and understorey. Hydrological processes that are quantified in the SVAT model of forest stands include precipitation, interception, evaporation, transpiration, snow accumulation and melt, soil and ground water movement, overland flow, horizontal subsurface flow and flow to forest ditches. In this report outlines for simplifying the existing SVAT model to a computational tool that can be used in biosphere modeling for long-term safety purposes are also given. The functioning of forest ecosystems on Olkiluoto Island is studied in Forest Intensive monitoring Plots (FIP): FIP4 (Scots pine forest), FIP10 (Norway spruce forest) and FIP11 (young Norway spruce/birch forest). Within the forest intensive monitoring plots (FIP4, 10 and 11) stand meteorological measurements are recorded once an hour. The parameters are air temperature, minimum and maximum temperature inside the crown layer and above the canopy, radiation, relative humidity, precipitation, soil moisture content, soil temperature and sap flow measurements (May 2007- June 2008). Measured versus computed cumulative stand throughfall were in good agreement with each other indicating that the SVAT model can be calibrated to reproduce very well the measured throughfall rates. Estimated stem flow was around 10% of precipitation for the Scots pine forest (FIP4), around 4 % for Norway spruce forest (FIP10) and about 3 % for young Norway spruce/birch forest (FIP11). For FIP4 the computed interception values were approximately 3-4 % bigger than the measured values but SVAT model predicted the yearly variation very well. For FIP10 average computed value was around 1 % smaller than the

Ecosystem characterization strategy at a repository site - Olkiluoto as a case study

Energy Technology Data Exchange (ETDEWEB)

Pere, Tuomas [Posiva Oy, Olkiluoto, 27160 Eurajoki (Finland); Kangasniemi, Ville [Environmental Research and Assessment EnviroCase, Ltd., Hallituskatu 1 D 4, 28100 Pori (Finland); Lahdenperae, Anne-Maj [Saanio and Riekkola Oy, Laulukuja 4, 00420 Helsinki (Finland); Aro, Lasse [Finnish Forest Research Institute, Kaironiementie 15, 39700 Parkano (Finland)

2014-07-01

Posiva Oy is constructing an underground research facility ONKALO in Olkiluoto, located in the municipality of Eurajoki, Finland. This is part of the plan for final disposal of spent nuclear fuel produced by Posiva's owners: Teollisuuden Voima Oyj and Fortum Power and Heat Oyj. Posiva has applied for construction license for an underground repository, which is planned to start its operation around the year 2020. The final disposal of high-level radioactive waste poses questions of long-term safety and possible processes of radionuclide release in the EBS (Engineered Barrier System) and the geosphere are also modelled as well as possible transport routes in the bedrock. Posiva has also established a monitoring program for the environment and is also conducting modelling of the surface environment and biosphere in Olkiluoto and the surrounding reference area. These serve the purpose of both, site description and modelling of the transport and accumulation of possible radionuclide releases in the surface environment and biosphere. The process of modelling used by Posiva requires the division of the surface environment and biosphere into several categories. In Posiva's classification, ecosystems are divided to two categories: terrestrial and aquatic with terrestrial divided to forests and agricultural areas. These categories are further divided to ecosystem types which include: lake, river, forest, cropland and sea (with coastal sea as a separate type). These types are even further divided to 14 ecosystem sub-types and behind these sub-types, a total of 24 biotopes exist. Soil and sediment types are also classified to 7 classes. The methodology behind the selection of these biotopes and their connection to the modelling of radionuclide transport in the surface environment is further described in the text. Some of the ecosystem types and biotopes are absent in present-day Olkiluoto area, which necessitates the use of reference targets, such as lakes, rivers

SR-Site groundwater flow modelling methodology, setup and results

International Nuclear Information System (INIS)

Selroos, Jan-Olof; Follin, Sven

2010-12-01

As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken three groundwater flow modelling studies. These are performed within the SR-Site project and represent time periods with different climate conditions. The simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. Three time periods are addressed; the Excavation and operational phases, the Initial period of temperate climate after closure, and the Remaining part of the reference glacial cycle. The present report is a synthesis of the background reports describing the modelling methodology, setup, and results. It is the primary reference for the conclusions drawn in a SR-Site specific context concerning groundwater flow during the three climate periods. These conclusions are not necessarily provided explicitly in the background reports, but are based on the results provided in these reports. The main results and comparisons presented in the present report are summarised in the SR-Site Main report

SR-Site groundwater flow modelling methodology, setup and results

Energy Technology Data Exchange (ETDEWEB)

Selroos, Jan-Olof (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Follin, Sven (SF GeoLogic AB, Taeby (Sweden))

2010-12-15

As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken three groundwater flow modelling studies. These are performed within the SR-Site project and represent time periods with different climate conditions. The simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. Three time periods are addressed; the Excavation and operational phases, the Initial period of temperate climate after closure, and the Remaining part of the reference glacial cycle. The present report is a synthesis of the background reports describing the modelling methodology, setup, and results. It is the primary reference for the conclusions drawn in a SR-Site specific context concerning groundwater flow during the three climate periods. These conclusions are not necessarily provided explicitly in the background reports, but are based on the results provided in these reports. The main results and comparisons presented in the present report are summarised in the SR-Site Main report.

Results of groundwater monitoring and vegetation sampling at Everest, Kansas, in 2009 .

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M.; Environmental Science Division

2010-05-13

In April 2008, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) conducted groundwater sampling for the analysis of volatile organic compounds (VOCs) in the existing network of monitoring points at Everest, Kansas (Argonne 2008). The objective of the 2008 investigation was to monitor the distribution of carbon tetrachloride contamination in groundwater previously identified in CCC/USDA site characterization and groundwater sampling studies at Everest in 2000-2006 (Argonne 2001, 2003, 2006a,b). The work at Everest is being undertaken on behalf of the CCC/USDA by Argonne National Laboratory, under the oversight of the Kansas Department of Health and Environment (KDHE). The findings of the 2008 investigation were as follows: (1) Measurements of groundwater levels obtained manually and through the use of automatic recorders demonstrated a consistent pattern of groundwater flow - and inferred contaminant migration - to the north-northwest from the former CCC/USDA facility toward the Nigh property, and then west-southwest from the Nigh property toward the intermittent creek that lies west of the former CCC/USDA facility and the Nigh property. (2) The range of concentrations and the areal distribution of carbon tetrachloride identified in the groundwater at Everest in April 2008 were generally consistent with previous results. The results of the 2008 sampling (reflecting the period from 2006 to 2008) and the earlier investigations at Everest (representing the period from 2000 to 2006) show that no significant downgradient extension of the carbon tetrachloride plume occurred from 2000 to 2008. (3) The slow contaminant migration indicated by the monitoring data is qualitatively consistent with the low groundwater flow rates in the Everest aquifer unit estimated previously on the basis of site-specific hydraulic testing (Argonne 2006a,b). (4) The April 2008 and earlier sampling results demonstrate that the limits of the plume have been

Indicator value of certain aquatic organisms for radioactive substances in the sea areas off the Loviisa and Olkiluoto nuclear power plants (Finland)[Radioecology

Energy Technology Data Exchange (ETDEWEB)

Ilus, E.; Klemola, S.; Ikaeheimonen, T.K.; Vartti, V.P.; Mattila, J. [STUK - radiation and Nuclear Safety Authority, Helsinki (Finland)

2006-04-15

The results of the marine radioecology studies carried out in 2000-2001 in the sea areas off the Loviisa and Olkiluoto Nuclear Power Plants (South and West coast of Finland) are reported. Extensive regular monitoring programmes of environmental radioactivity have been carried out already for about 30 years in these areas. The aim of the present study was to compare the indicator value of the various members of the aquatic ecosystem with respect to environmental monitoring. Samples were taken from 27 species including phytoplankton (9 samples), zooplankton (9 samples), periphyton (12 samples), macroalgae and vascular plants (16 samples), benthic animals (8 samples), fish (20 samples) and birds (6). Special attention was paid to different tissues and organs of fish and birds, such as flesh, liver, entrails, bones, milt, spawn, eggs, egg shells etc. (in total 64 samples), because there has been a lot of debate among the opponents of nuclear power in the course of time about the role these objects in the environmental monitoring of the power plants. The samples were taken from relatively small areas both in Loviisa and Olkiluoto, which makes the results well comparable inside each of the sites. (au)

Geophysical borehole logging of the boreholes KR37, KR37B and KR38, at Olkiluoto 2005

International Nuclear Information System (INIS)

Majapuro, J.

2006-03-01

Suomen Malmi Oy conducted geophysical borehole logging of the boreholes KR37, KR37b and KR38 at the Olkiluoto site in Eurajoki during September and October 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and processing of the acoustic data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

Optical imaging of the boreholes KR37, KR37B and KR38 at Olkiluoto 2005

International Nuclear Information System (INIS)

Majapuro, J.

2006-02-01

Suomen Malmi Oy conducted optical imaging surveys of the boreholes KR37, KR37B and KR38 at the Olkiluoto site in Eurajoki during September 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and preliminary processing of the images. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality through example images. The raw and processed data are delivered digitally in WellCAD format. The images are also attached to the appendix CD of this report in Adobe Acrobat PDF-format. (orig.)

Electromagnetic SAMPO monitoring soundings at Olkiluoto 2011 with updated interpretations

International Nuclear Information System (INIS)

Korhonen, K.

2013-11-01

The Geological Survey of Finland (GTK) has carried out electromagnetic depth soundings annually at fixed stations in Olkiluoto since 2004 as part of a monitoring programme. The goal of the programme is to detect and monitor changes in the electrical properties of the bedrock above and in the vicinity of the underground nuclear waste disposal facility. A new Sampo monitoring survey was carried out during September-October 2011. The survey resulted in 39 soundings at 17 measurement stations. The nominal coil separations of 200, 400, 500, 600 and 800 meters were used. Eight stations were selected for detailed annual layer-model interpretation. The layer models were based on prior geological and geophysical knowledge of the area. The thicknesses of the layer-model layers were kept fixed whereas their resistivities were solved for each subsequent year independent of each other. Many time series indicate clear trends in electrical resistivity. However, even though the data was carefully corrected and edited, the time series display a fairly large amount of variability increasing the uncertainty of the calculated trends. (orig.)

In-situ experiments to investigate rock matrix retention properties in ONKALO, Olkiluoto, Finland

Energy Technology Data Exchange (ETDEWEB)

Voutilainen, Mikko; Helariutta, Kerttuli [Helsinki Univ. (Finland). Dept. of Chemistry; Poteri, Antti [Technical Research Centre of Finland VTT (Finland); and others

2015-07-01

Spent nuclear fuel from nuclear power plants, owned by TVO (Teollisuuden Voima Oy) and Fortum, is planned to be disposed to a repository at a depth of more than 400 meters in the bedrock of Olkiluoto (Eurajoki, Finland). The repository system of multiple release barriers consists of both manmade and natural barriers. The surrounding rock acts as the last barrier if other barriers fail during passage of the millennia. Therefore, safe disposal of spent nuclear fuel requires information on the radionuclide transport and retention properties within the porous and water-containing rock matrix along the water conducting flow paths. To this end, various types of experiments are being performed and planned within ONKALO, the underground rock characterization facility in Olkiluoto, as part of the project @''rock matrix REtention PROperties'' (REPRO). The research site is located at a depth of 420 meters close to the repository site. The aim is to study the diffusion and sorption properties of nuclear compounds in the rock matrix under real in-situ conditions. The first in-situ experiment was performed during 2012 using HTO, Na-22, Cl-36 and I-125 as tracer nuclides. Breakthrough curves show retention and asymptotic behavior that are in-line with those caused by matrix diffusion and sorption were observed in their breakthrough curves. Weak sorption was also observed in the breakthrough curves of Na-22 and I-125.

Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Summary report

International Nuclear Information System (INIS)

Smith, Paul; Neall, Fiona; Snellman, Margit; Pastina, Barbara; Nordman, Henrik; Johnson, Lawrence; Hjerpe, Thomas

2008-03-01

The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. This safety assessment is summarised in the present report. The scientific basis of the safety assessment includes around 30 years of scientific RandD and technical development in the Swedish and Finnish KBS-3V programmes. Much of this scientific basis is directly applicable to KBS-3H. This has allowed the KBS-3H safety studies to focus on those issues that are unique to this design alternative, identified in a systematic 'difference analysis' of KBS-3H and KBS-3V. This difference analysis has shown that the key differences in the evolution and performance of KBS-3H and KBS-3V relate mainly to the engineered barrier system and to the impact of local variations in the rate of groundwater inflow on buffer saturation along the KBS-3H deposition drifts. No features or processes specific to KBS-3H have been identified that could lead to a loss or substantial degradation of the safety functions of the engineered barriers over a million year time frame. Radionuclide release from the repository near field in the event of

Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Summary report

Energy Technology Data Exchange (ETDEWEB)

Smith, Paul; Neall, Fiona; Snellman, Margit; Pastina, Barbara; Nordman, Henrik; Johnson, Lawrence; Hjerpe, Thomas

2008-03-15

The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. This safety assessment is summarised in the present report. The scientific basis of the safety assessment includes around 30 years of scientific RandD and technical development in the Swedish and Finnish KBS-3V programmes. Much of this scientific basis is directly applicable to KBS-3H. This has allowed the KBS-3H safety studies to focus on those issues that are unique to this design alternative, identified in a systematic 'difference analysis' of KBS-3H and KBS-3V. This difference analysis has shown that the key differences in the evolution and performance of KBS-3H and KBS-3V relate mainly to the engineered barrier system and to the impact of local variations in the rate of groundwater inflow on buffer saturation along the KBS-3H deposition drifts. No features or processes specific to KBS-3H have been identified that could lead to a loss or substantial degradation of the safety functions of the engineered barriers over a million year time frame. Radionuclide release from the repository near field in the

Olkiluoto 3: Finland has chosen a EPR

International Nuclear Information System (INIS)

Brummer, S.

2003-01-01

According to the Finn law any nuclear project has to be declared conformed to the general interest of the country by the government and then has to be approved by the parliament. In may 2002 the Finn parliament approved the project of the TVO company: the construction of a new nuclear unit on the Olkiluoto site and the direct and definitive disposal of spent fuels in the granite underground layers of the same site. The project was agreed with 109 votes for and 92 against. In september 2002 an international invitation to tender was launched and 4 companies made proposals: Westinghouse, Atomstroexport, Framatome-ANP and General Electric. Westinghouse withdrew its offer some time later. In october 2003 TVO announced that the unit will be a 1600 MW EPR (European pressurized reactor) built by Framatome-ANP. The construction work will begin in spring 2005 and the unit is scheduled to enter into service in 2009. At that time the contribution of nuclear energy to the Finn energy production will reach 35%. (A.C.)

Modernisation of the Olkiluoto nuclear power plant increases the power production efficiency under safe limits

International Nuclear Information System (INIS)

Valkeapaeae, R.

1995-01-01

Teollisuuden Voima Oy published the efficiency increment plans as a part of the modernisation of the Olkiluoto nuclear power plant. The power of the reactor units, originally designed for 660 MW will now be increased for a second time. The former improvements were made in 1994. The power of the units was increased to 710 MW. After this new renovation the power of the both units will be 830-840 MW. (2 figs.)

The Site Selected. The Local Decision-Making Regarding the Siting of the Spent Nuclear Fuel Repository in Olkiluoto

International Nuclear Information System (INIS)

Kojo, Matti

2006-01-01

In May 1999 Posiva, the company responsible for the final disposal of spent nuclear fuel in Finland, suggested that the Finnish Government considers only Olkiluoto in Eurajoki in its application of a decision in principle to be a final disposal site. In January 2000 the municipal council of Eurajoki made a positive statement on the decision in principle. The Government made the decision in principle in Dec 2000, and the Parliament ratified the decision in May 2001. The paper is focused on the decision making of Eurajoki municipality regarding the siting of the spent nuclear fuel repository. The paper shows how the interaction between the representatives of the candidate municipality and the nuclear energy industry was the crucial factor in the decision-making. Eurajoki serves as an example, in where the parties reached an agreement of the compensations for the final disposal repository. The negotiations between the Eurajoki municipality and the nuclear energy industry in reaching a positive decision are analysed from the beginning of the 1980s. The main emphasis is however on the years 1996-99, when the nuclear energy industry negotiated with the municipality on the compensation for the final disposal repository. The loss of income was an important reason why some of the councillors of Eurajoki were interested in having the final disposal repository in Olkiluoto. The industry's problem on the other hand was to safeguard the final disposal site. From the TVO's angle Olkiluoto was a potential final disposal site for example for its limited need for transport and for the existing infrastructure. The company used the financial benefits of the project as its trump card. The attitude of Eurajoki municipality to the final disposal of spent nuclear fuel turned positive with the Olkiluoto vision in December 1998, when still five years earlier the municipal council was prepared to act and prevent the final disposal. The future image presented by the municipality now matched

The Site Selected. The Local Decision-Making Regarding the Siting of the Spent Nuclear Fuel Repository in Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Kojo, Matti [Univ. of Tampere (Finland). Dept. of Political Science and International Relations

2006-09-15

In May 1999 Posiva, the company responsible for the final disposal of spent nuclear fuel in Finland, suggested that the Finnish Government considers only Olkiluoto in Eurajoki in its application of a decision in principle to be a final disposal site. In January 2000 the municipal council of Eurajoki made a positive statement on the decision in principle. The Government made the decision in principle in Dec 2000, and the Parliament ratified the decision in May 2001. The paper is focused on the decision making of Eurajoki municipality regarding the siting of the spent nuclear fuel repository. The paper shows how the interaction between the representatives of the candidate municipality and the nuclear energy industry was the crucial factor in the decision-making. Eurajoki serves as an example, in where the parties reached an agreement of the compensations for the final disposal repository. The negotiations between the Eurajoki municipality and the nuclear energy industry in reaching a positive decision are analysed from the beginning of the 1980s. The main emphasis is however on the years 1996-99, when the nuclear energy industry negotiated with the municipality on the compensation for the final disposal repository. The loss of income was an important reason why some of the councillors of Eurajoki were interested in having the final disposal repository in Olkiluoto. The industry's problem on the other hand was to safeguard the final disposal site. From the TVO's angle Olkiluoto was a potential final disposal site for example for its limited need for transport and for the existing infrastructure. The company used the financial benefits of the project as its trump card. The attitude of Eurajoki municipality to the final disposal of spent nuclear fuel turned positive with the Olkiluoto vision in December 1998, when still five years earlier the municipal council was prepared to act and prevent the final disposal. The future image presented by the municipality

Geochemical Investigations of Groundwater Stability

International Nuclear Information System (INIS)

Bath, Adrian

2006-05-01

groundwaters, and also by stable isotopes and uranium isotopes in secondary minerals. Information on timing of water and solute movements is important because it indicates any correlation with the timing of external events that might have perturbed and destabilised the groundwater system in the past, and allows a timescale to be estimated for the persistence of stable conditions. Data from a number of published site investigation projects and research programmes are reviewed to illustrate the patterns of geochemical data and the relationships between them, and how these are interpreted in terms of hydrodynamic stability. Data from Aespoe and Stripa and from exploratory boreholes at Finnsjoen and other sites in Sweden are compiled and discussed. Preliminary data from SKB's ongoing site investigations at Simpevarp/Laxemar and Forsmark are not considered in detail but their general similarities with Aespoe and Finnsjoen/SFR respectively are introduced into the discussion of geochemical evidence for groundwater stability in inland and coastal areas. Relevant data from Finnish sites including Olkiluoto, from the Whiteshell URL area in Canada, from Sellafield in the UK, and from the Tono area and URL in Japan are also summarised in appendices and discussed because they add further insights into the interpretation of geochemical indicators for a range of geological environments. The compiled data provide only limited scope for comparison of groundwater evolution and stability between inland and coastal areas in Sweden, because of the patchiness of representative data especially from early site studies. The external changes that might have perturbed stable groundwater conditions in the past are glaciation (i.e. melt water, mechanical loading/unloading and permafrost) and varying sea water infiltration at coastal sites due to changes in palaeo-Baltic and isostatic conditions. The present distributions of palaeo-Baltic sea water in groundwaters at coastal sites vary, reflecting local

Geophysical borehole logging of the boreholes KR23 extension, KR29 and KR29b at Olkiluoto 2004

International Nuclear Information System (INIS)

Lahti, M.; Heikkinen, E.

2005-04-01

Suomen Malmi Oy conducted geophysical borehole logging of the boreholes KR23 extension, KR25b, KR29 and KR29b at the Olkiluoto site in Eurajoki during October 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and processing of the acoustic data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

Geophysical borehole logging of the boreholes KR23 extension, KR29 and KR29b at Olkiluoto 2004

Energy Technology Data Exchange (ETDEWEB)

Lahti, M. [Suomen Malmi Oy, Espoo (Finland); Heikkinen, E. [JP-Fintact Oy, Vantaa (Finland)

2005-04-15

Suomen Malmi Oy conducted geophysical borehole logging of the boreholes KR23 extension, KR25b, KR29 and KR29b at the Olkiluoto site in Eurajoki during October 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and processing of the acoustic data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

Vadose Zone Nitrate Transport Dynamics Resulting from Agricultural Groundwater Banking

Science.gov (United States)

Murphy, N. P.; McLaughlin, S.; Dahlke, H. E.

2017-12-01

In recent years, California's increased reliance on groundwater resources to meet agricultural and municipal demands has resulted in significant overdraft and water quality issues. Agricultural groundwater banking (AGB) has emerged as a promising groundwater replenishment opportunity in California; AGB is a form of managed aquifer recharge where farmland is flooded during the winter using excess surface water in order to recharge the underlying groundwater. Suitable farmland that is connected to water delivery systems is available for AGB throughout the Central Valley. However, questions remain how AGB could be implemented on fertilized agricultural fields such that nitrate leaching from the root zone is minimized. Here, we present results from field and soil column studies that investigate the transport dynamics of nitrogen in the root and deeper vadose zone during flooding events. We are specifically interested in estimating how timing and duration of flooding events affect percolation rates, leaching and nitrification/denitrification processes in three soil types within the Central Valley. Laboratory and field measurements include nitrogen (NO3-, NH4+, NO2-, N2O), redox potentials, total organic carbon, dissolved oxygen, moisture content and EC. Soil cores are collected in the field before and after recharge events up to a depth of 4m, while other sensors monitor field conditions continuously. Preliminary results from the three field sites show that significant portions of the applied floodwater (12-62 cm) infiltrated below the root zone: 96.1% (Delhi), 88.6% (Modesto) and 76.8% (Orland). Analysis of the soil cores indicate that 70% of the residual nitrate was flushed from the sandy soil, while the fine sandy loam showed only a 5% loss and in some cores even an increase in soil nitrate (in the upper 20cm). Column experiments support these trends and indicate that increases in soil nitrate in the upper root zone might be due to organic nitrogen mineralization and

Updated comparison of groundwater flow model results and isotopic data in the Leon Valley, Mexico

Science.gov (United States)

Hernandez-Garcia, G. D.

2015-12-01

Northwest of Mexico City, the study area is located in the State of Guanajuato. Leon Valley has covered with groundwater its demand of water, estimated in 20.6 cubic meters per second. The constant increase of population and economic activities in the region, mainly in cities and automobile factories, has also a constant growth in water needs. Related extraction rate has produced an average decrease of approximately 1.0 m per year over the past two decades. This suggests that the present management of the groundwater should be checked. Management of groundwater in the study area involves the possibility of producing environmental impacts by extraction. This vital resource under stress becomes necessary studying its hydrogeological functioning to achieve scientific management of groundwater in the Valley. This research was based on the analysis and integration of existing information and the field generated by the authors. On the base of updated concepts like the geological structure of the area, the hydraulic parameters and the composition of deuterium-delta and delta-oxygen -18, this research has new results. This information has been fully analyzed by applying a groundwater flow model with particle tracking: the result has also a similar result in terms of travel time and paths derived from isotopic data.

Safeguards for final disposal of spent nuclear fuel. Methods and technologies for the Olkiluoto site

International Nuclear Information System (INIS)

Okko, O.

2003-05-01

The final disposal of the nuclear material shall introduce new safeguards concerns which have not been addressed previously in IAEA safeguards approaches for spent fuel. The encapsulation plant to be built at the site will be the final opportunity for verification of spent fuel assemblies prior to their transfer to the geological repository. Moreover, additional safety and safeguards measures are considered for the underground repository. Integrated safeguards verification systems will also concentrate on environmental monitoring to observe unannounced activities related to possible diversion schemes at the repository site. The final disposal of spent nuclear fuel in geological formation will begin in Finland within 10 years. After the geological site investigations and according to legal decision made in 2001, the final repository of the spent nuclear fuel shall be located at the Olkiluoto site in Eurajoki. The next phase of site investigations contains the construction of an underground facility, called ONKALO, for rock characterisation purposes. The excavation of the ONKALO is scheduled to start in 2004. Later on, the ONKALO may form a part of the final repository. The plans to construct the underground facility for nuclear material signify that the first safeguards measures, e.g. baseline mapping of the site area, need to take prior to the excavation phase. In order to support the development and implementation of the regulatory control of the final disposal programme, STUK established an independent expert group, LOSKA. The group should support the STUK in the development of the technical safeguards requirements, in the implementation of the safeguards and in the evaluation of the plans of the facility operator. This publication includes four background reports produced by this group. The first of these 'NDA verification of spent fuel, monitoring of disposal canisters, interaction of the safeguards and safety issues in the final disposal' describes the new

Semi-integration of overcoring stress data and review of rock stress data at the Olkiluoto site

International Nuclear Information System (INIS)

Ask, D.

2011-06-01

This project involves a semi-integration of collected rock stress data at Olkiluoto. The data included in the study involves overcoring and hydraulic fracturing data reported in the 2006 Site Report, supplemented with the additional data gathered since then, measurements for the power plant construction, and measurements in ONKALO. Despite the extensive data, and although the data display a fair correspondence with respect to stress magnitudes between methods, a few discrepancies between methods exist. The discrepancies primarily concern the orientation of the horizontal stresses and the magnitude of maximum horizontal stress. The objective of the study is help answer the remaining discrepancies in the collected data using a semi-integration approach on the overcoring data, i.e. a simplified application of the Integrated Stress Determination Method. The semi-integration involves two steps: (i) a brief re-evaluation of data; and (ii) forced overcoring stress calculations based on constraints derived from the other stress measurement techniques. The overall intension was to force overcoring data, which is the method displaying the largest scatter in results at the Olkiluoto site, to be consistent with a number of constraints that were derived from other stress measurement techniques. This exercise would outline the most probable constraints and in the extension, help identifying a stress model for the site. Regrettably, the results of the semi-integration were not completely satisfactory. The most important factor of this outcome is believed to be the failure to reduce the initial scatter through a re-evaluation. The remaining scatter after re-evaluation is judged too large to represent solely in situ stress variation; hence, measurement related errors are likely still present in the re-evaluated data set. A more in-depth analysis may to some extent decrease the scatter in data, but perhaps more effectively, develop a tool that simultaneously can derive the stress

Uncertainty and sensitivity results for pre-waste-emplacement groundwater travel time

International Nuclear Information System (INIS)

Kaplan, P.G.

1992-01-01

In this paper uncertainty and sensitivity analyses for pre-waste-emplacement groundwater travel time conducted. Although preliminary, a numbed of interesting results were obtained. Uncertainty in the ground water travel time statistics, as measured by the coefficient of variation, increases and then decrease as the modeled system transitions from matrix-dominated to fracture-dominated flow. The uncertainty analysis also suggests that the median, as opposed to the mean, may be a better indicator of performance with respect to the regulatory criterion. The sensitivity analysis shows a strong correlation between an effective fracture property, fracture porosity, and failure to meet the regulatory pre-waste-emplacement groundwater travel time criterion of 1,000 years

Variable infiltration and river flooding resulting in changing groundwater quality - A case study from Central Europe

Science.gov (United States)

Miotliński, Konrad; Postma, Dieke; Kowalczyk, Andrzej

2012-01-01

SummaryThe changes in groundwater quality occurring in a buried valley aquifer following a reduction in groundwater exploitation and enhanced infiltration due to extensive flooding of the Odra River in 1997 were investigated. Long-time series data for the chemical composition of groundwater in a large well field for drinking water supply indicated the deterioration of groundwater quality in the wells capturing water from the flooded area, which had been intensively cultivated since the 1960s. Infiltration of flooded river water into the aquifer is suggested by an elevated chloride concentration, although salt flushing from the rewatered unsaturated zone due to the enhanced recharge event is much more feasible. Concomitantly with chloride increases in the concentrations of sulphate, ferrous iron, manganese, and nickel imply the oxidation of pyrite (FeS 2) which is abundant in the aquifer. The proton production resulting from pyrite oxidation is buffered by the dissolution of calcite, while the Ca:SO 4 stoichiometry of the groundwater indicates that pyrite oxidation coupled with nitrate reduction is the dominant process occurring in the aquifer. The pyritic origin of SO42- is confirmed by the sulphur isotopic composition. The resultant Fe 2+ increase induces Mn-oxide dissolution and the mobilisation of Ni 2+ previously adsorbed to Mn-oxide surfaces. The study has a major implication for groundwater quality prediction studies where there are considerable variations in water level associated with groundwater management and climate change issues.

Geochemical Investigations of Groundwater Stability

Energy Technology Data Exchange (ETDEWEB)

Bath, Adrian [Intellisci Ltd., Loughborough (United Kingdom)

2006-05-15

groundwaters, and also by stable isotopes and uranium isotopes in secondary minerals. Information on timing of water and solute movements is important because it indicates any correlation with the timing of external events that might have perturbed and destabilised the groundwater system in the past, and allows a timescale to be estimated for the persistence of stable conditions. Data from a number of published site investigation projects and research programmes are reviewed to illustrate the patterns of geochemical data and the relationships between them, and how these are interpreted in terms of hydrodynamic stability. Data from Aespoe and Stripa and from exploratory boreholes at Finnsjoen and other sites in Sweden are compiled and discussed. Preliminary data from SKB's ongoing site investigations at Simpevarp/Laxemar and Forsmark are not considered in detail but their general similarities with Aespoe and Finnsjoen/SFR respectively are introduced into the discussion of geochemical evidence for groundwater stability in inland and coastal areas. Relevant data from Finnish sites including Olkiluoto, from the Whiteshell URL area in Canada, from Sellafield in the UK, and from the Tono area and URL in Japan are also summarised in appendices and discussed because they add further insights into the interpretation of geochemical indicators for a range of geological environments. The compiled data provide only limited scope for comparison of groundwater evolution and stability between inland and coastal areas in Sweden, because of the patchiness of representative data especially from early site studies. The external changes that might have perturbed stable groundwater conditions in the past are glaciation (i.e. melt water, mechanical loading/unloading and permafrost) and varying sea water infiltration at coastal sites due to changes in palaeo-Baltic and isostatic conditions. The present distributions of palaeo-Baltic sea water in groundwaters at coastal sites vary, reflecting

Geophysical borehole logging, dummy-sonding and optical imaging of the borehole OL-KR24 at Olkiluoto 2005

International Nuclear Information System (INIS)

Majapuro, J.

2006-03-01

Suomen Malmi Oy conducted geophysical borehole logging, dummy-sonding and optical imaging surveys of the borehole OL-KR24 at the Olkiluoto site in Eurajoki during 1.10.2005 - 4.10.2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are caliper survey and optical imaging. The assignment included the field work of surveys, interpretation and processing of the data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

Simulation of Groundwater Flow, Denpasar-Tabanan Groundwater Basin, Bali Province

Directory of Open Access Journals (Sweden)

Heryadi Tirtomihardjo

2014-06-01

Full Text Available DOI: 10.17014/ijog.v6i3.123Due to the complex structure of the aquifer systems and its hydrogeological units related with the space in which groundwater occurs, groundwater flows were calculated in three-dimensional method (3D Calculation. The geometrical descritization and iteration procedures were based on an integrated finite difference method. In this paper, all figures and graphs represent the results of the calibrated model. Hence, the model results were simulated by using the actual input data which were calibrated during the simulation runs. Groundwater flow simulation of the model area of the Denpasar-Tabanan Groundwater Basin (Denpasar-Tabanan GB comprises steady state run, transient runs using groundwater abstraction in the period of 1989 (Qabs-1989 and period of 2009 (Qabs-2009, and prognosis run as well. Simulation results show, in general, the differences of calculated groundwater heads and observed groundwater heads at steady and transient states (Qabs-1989 and Qabs-2009 are relatively small. So, the groundwater heads situation simulated by the prognosis run (scenario Qabs-2012 are considerably valid and can properly be used for controlling the plan of groundwater utilization in Denpasar-Tabanan GB.

Monitoring and Assessing Groundwater Impacts on Vegetation Health in Groundwater Dependent Ecosystems

Science.gov (United States)

Rohde, M. M.; Ulrich, C.; Howard, J.; Sweet, S.

2017-12-01

Sustainable groundwater management is important for preserving our economy, society, and environment. Groundwater supports important habitat throughout California, by providing a reliable source of water for these Groundwater Dependent Ecosystems (GDEs). Groundwater is particularly important in California since it supplies an additional source of water during the dry summer months and periods of drought. The drought and unsustainable pumping practices have, in some areas, lowered groundwater levels causing undesirable results to ecosystems. The Sustainable Groundwater Management Act requires local agencies to avoid undesirable results in the future, but the location and vulnerabilities of the ecosystems that depend on groundwater and interconnected surface water is often poorly understood. This presentation will feature results from a research study conducted by The Nature Conservancy and Lawrence Berkeley National Laboratory that investigated how changes in groundwater availability along an interconnected surface water body can impact the overall health of GDEs. This study was conducted in California's Central Valley along the Cosumnes River, and situated at the boundary of a high and a medium groundwater basin: South American Basin (Sacramento Hydrologic Region) and Cosumnes Basin (San Joaquin Hydrologic Region). By employing geophysical methodology (electrical resistivity tomography) in this study, spatial changes in groundwater availability were determined under groundwater-dependent vegetation. Vegetation survey data were also applied to this study to develop ecosystem health indicators for groundwater-dependent vegetation. Health indicators for groundwater-dependent vegetation were found to directly correlate with groundwater availability, such that greater availability to groundwater resulted in healthier vegetation. This study provides a case study example on how to use hydrological and biological data for setting appropriate minimum thresholds and

Finnish EPR Olkiluoto 3. The world's first third-generation reactor now under construction

International Nuclear Information System (INIS)

2007-01-01

The EPR was developed by Framatome and Siemens KWU (the nuclear division of Siemens), whose nuclear activities were combined in January 2001 to form Framatome ANP, now AREVA NP. The French electricity utility EDF (Electricite de France), together with the major German utilities, played an active role in the project. The safety authorities of the two countries joined forces to bring their respective safety standards into line and draw up joint design rules for the new reactor. On December 18, 2003, the consortium formed by AREVA and Siemens - and led by AREVA - signed a contract with TVO for the turnkey construction of the EPR. The overall Olkiluoto 3 project cost has been estimated by TVO at around euros 3 Billion. TVO is responsible for the overall project management and licensing process with the Finnish Safety Authority STUK. In the pre-qualification phase, STUK concluded that the EPR can meet the Finnish licensing requirements. All specific comments will be taken into account for the realization of the project. In January 2005, STUK emphasized in its safety assessment that the evolutionary EPR design compared to predecessor product lines has been further enhanced by AREVA. This paper presents first, The Finnish energy situation (Electricity consumption and supply, Finland's Kyoto CO 2 cutback, Competitiveness of nuclear power), and then the EPR in Olkiluoto (General schedule of responsibilities, Important milestones of the project). Finally, the EPR third-generation and advanced reactor is presented with its position in the international competition (Targeted design objectives, Main characteristics, competitiveness, safety, Additional measures to prevent the occurrence of events likely to damage the core, Increased protection against the consequences of core melt)

Results of the groundwater quality assessment program at the 216-A-29 ditch RCRA facility

International Nuclear Information System (INIS)

Votava, J.M.

1995-01-01

This report presents the findings of the groundwater quality assessment program for the 216-A-29 Ditch. The information presented in this report Ditch have affected the quality of the groundwater in the unconfined aquifer beneath the facility. The results indicate that the 216-A-29 Ditch is the source of elevated specific conductance in well 299-E25-35 and that the source is nonhazardous. This report describes the current monitoring status of the 216-A-29 Ditch, groundwater chemical data interpretation, and recommends the reinstatement of an indicator-evaluation monitoring program in accordance with 40 CFR 265.93(d)(6)

Seismic VSP Investigations at Olkiluoto, 2005

Energy Technology Data Exchange (ETDEWEB)

Enescu, N.; Cosma, C.; Balu, L. (Vibrometric, Vantaa (Finland))

2007-08-15

Posiva Oy carries out R and D related tasks for spent nuclear fuel disposal in Finland. The site characterization has been conducted since 1987 in Olkiluoto in western Finland. The ONKALO underground characterization facility has been under construction since 2004. Vibrometric Oy has been contracted to carry out seismic VSP survey in four drillholes in the immediate vicinity of ONKALO, for the characterization of the seismically responsive structures. Four drillholes, KR8, KR27, KR29 and KR38 were included to the project. Seven seismic source locations on ground surface were used for each drillhole. The source locations were optimized with respect to the drillhole and ONKALO and were configured as linear arrays to produce optimum imaging focused on the ONKALO volume. A mechanical Vibsist source, using a hydraulic rock breaker mounted on a 22 t excavator, was used as source of seismic signal. The signal was recorded with downhole 3-component geophones. The recording array was 8-level long, with 5 m spacing between levels. Acquisition was run throughout the drillholes. Processing of the VSP profiles consisted of time decoding of the impact sequences, filtering and image point (IP) transform. The interpretation was carried out interactively, seeking for best match of orientation of each reflection according to different borehole profiles where the features were seen. The interpretations were built as an add-on to a previous seismic model of the site. The most distinct reflectors were interpreted, compiled to as a part of a terrain model composed of 3D surfaces, and transferred digitally together with other results (3D elements of reflector locations) into Posiva's 3D modeling system. Some of the reflectors have already received direct confirmation from ONKALO observations. (orig.)

Seismic VSP Investigations at Olkiluoto, 2005

International Nuclear Information System (INIS)

Enescu, N.; Cosma, C.; Balu, L.

2007-08-01

Posiva Oy carries out R and D related tasks for spent nuclear fuel disposal in Finland. The site characterization has been conducted since 1987 in Olkiluoto in western Finland. The ONKALO underground characterization facility has been under construction since 2004. Vibrometric Oy has been contracted to carry out seismic VSP survey in four drillholes in the immediate vicinity of ONKALO, for the characterization of the seismically responsive structures. Four drillholes, KR8, KR27, KR29 and KR38 were included to the project. Seven seismic source locations on ground surface were used for each drillhole. The source locations were optimized with respect to the drillhole and ONKALO and were configured as linear arrays to produce optimum imaging focused on the ONKALO volume. A mechanical Vibsist source, using a hydraulic rock breaker mounted on a 22 t excavator, was used as source of seismic signal. The signal was recorded with downhole 3-component geophones. The recording array was 8-level long, with 5 m spacing between levels. Acquisition was run throughout the drillholes. Processing of the VSP profiles consisted of time decoding of the impact sequences, filtering and image point (IP) transform. The interpretation was carried out interactively, seeking for best match of orientation of each reflection according to different borehole profiles where the features were seen. The interpretations were built as an add-on to a previous seismic model of the site. The most distinct reflectors were interpreted, compiled to as a part of a terrain model composed of 3D surfaces, and transferred digitally together with other results (3D elements of reflector locations) into Posiva's 3D modeling system. Some of the reflectors have already received direct confirmation from ONKALO observations. (orig.)

Cross-Borehole research with EMRE-system. Radiofrequency measurements in drillhole section OL-KR40 - OL-KR45 at Olkiluoto, 2009

International Nuclear Information System (INIS)

Korpisalo, A.; Niemelae, M.

2010-04-01

Posiva Oy carries out research and development work for the spent nuclear fuel disposal in Finland. The repository will be constructed deep in the crystalline bedrock at Olkiluoto island in Eurajoki. Construction of the underground characterization facility ONKALO started in 2004. Posiva Oy has been actively reviewing the methods for examining granitic i.e. crystalline bedrock properties. One of the considered methods was electromagnetic cross-borehole survey. This report describes the field work carried out in 2009 and the interpretation of the continuous wave device in one drillhole panel at 100-750 m depth level. Panel was conic in shape thus the collars were in close vicinity (about 10 m) at the earth surface and diverged in deeper parts being several hundreds of meters from each others. The works were carried out by Geological Survey of Finland. After the pioneering work in 2005 the device was repaired thoroughly and the proper functioning of the device was ensured after several tests. Geological-geophysical characterization of Olkiluoto site has been run since 1989, and more than 40 drillholes have been prepared

Geochemistry of shale groundwaters: Results of preliminary laboratory leaching experiments

International Nuclear Information System (INIS)

Von Damm, K.L.; Johnson, K.O.

1987-09-01

Twelve shales were reacted with distilled water at 20 0 C and 100 0 C; the composition of the waters and the mineralogy were determined before and after reaction. The experiments were conducted in a batch mode over a period of approximately 40 days. Major changes occurred in the solution chemistry; in most cases sulfate became the dominant anion while either sodium or calcium was the major cation. The high sulfate is most likely a result of the oxidation of pyrite in the samples. In the 100 0 C experiments some of the solutions became quite acidic. Examination of the observed mineralogy and comparison to the mineral assemblage calculated to be in equilibrium with the experimentally determined waters, suggests that the acidic waters are generated when no carbonate minerals remain to buffer the groundwaters to a more neutral pH. The pH of shale waters will be determined by the balance between the oxidation of pyrite and organic matter and the dissolution of carbonate minerals. The experimental data are helping to elucidate the chemical reactions that control the pH of shale groundwaters, a critical parameter in determining other water-rock and waste-water-rock interactions and ultimate solute mobility. An experimental approach also provides a means of obtaining data for shales for which no groundwater data are available as well as data on chemical species which are not usually determined or reported

Geochemistry of shale groundwaters: Results of preliminary laboratory leaching experiments

Energy Technology Data Exchange (ETDEWEB)

Von Damm, K.L.; Johnson, K.O.

1987-09-01

Twelve shales were reacted with distilled water at 20/sup 0/C and 100/sup 0/C; the composition of the waters and the mineralogy were determined before and after reaction. The experiments were conducted in a batch mode over a period of approximately 40 days. Major changes occurred in the solution chemistry; in most cases sulfate became the dominant anion while either sodium or calcium was the major cation. The high sulfate is most likely a result of the oxidation of pyrite in the samples. In the 100/sup 0/C experiments some of the solutions became quite acidic. Examination of the observed mineralogy and comparison to the mineral assemblage calculated to be in equilibrium with the experimentally determined waters, suggests that the acidic waters are generated when no carbonate minerals remain to buffer the groundwaters to a more neutral pH. The pH of shale waters will be determined by the balance between the oxidation of pyrite and organic matter and the dissolution of carbonate minerals. The experimental data are helping to elucidate the chemical reactions that control the pH of shale groundwaters, a critical parameter in determining other water-rock and waste-water-rock interactions and ultimate solute mobility. An experimental approach also provides a means of obtaining data for shales for which no groundwater data are available as well as data on chemical species which are not usually determined or reported.

Assessment of doses to non-human biota: Review of developments and demonstration assessment for Olkiluoto repository

International Nuclear Information System (INIS)

Smith, K.; Robinson, C.

2006-12-01

This report provides a summary of work commissioned by Posiva Oy and undertaken by Enviros Consulting Ltd to support the development of a strategy for the assessment of environmental impacts from ionising radiation associated with the Olkiluoto waste repository, Finland, as part of the development of the Posiva Safety Case Portfolio. This project included a review of the development of international policies and standards related to protection of biota from the effects of ionizing radiation and of biota assessment methodologies, paying particular attention to those that have been applied to waste repository performance assessments. On the basis of this review, recommendations were developed on the most appropriate methodology to apply in order to assess the impact of radioactive releases from the planned spent fuel repository in Olkiluoto. A test-case was developed, in collaboration with staff from Posiva and Facilia AB, and an assessment was performed. The results and experience of which were analysed and summarised to develop recommendations for a future strategy. The test case highlighted some significant data gaps related to the assessment of impacts to both generic biota types and to interest species. In particular, concentration ratios for generic carnivorous mammals and migratory species such as moose that may consume food from multiple ecosystems and dose conversion factors for large burrowing (i.e. hibernating) mammals. However, in general terms, the dose rates predicted for all organism types were several orders of magnitude below those at which population effects would be expected to be observed and those at which effects on the individual may be anticipated. There would therefore be scope for simplifying the approach applied, although there would be value in performing a sensitivity analysis to ensure that the simplification is applied appropriately. There would also be value in ensuring consistency of the developing approach for non-human biota with

Assessment of doses to non-human biota: Review of developments and demonstration assessment for Olkiluoto repository

Energy Technology Data Exchange (ETDEWEB)

Smith, K. [Carol Robinson Enviros Consulting Ltd, Edinburgh (United Kingdom)

2006-12-15

This report provides a summary of work commissioned by Posiva Oy and undertaken by Enviros Consulting Ltd to support the development of a strategy for the assessment of environmental impacts from ionising radiation associated with the Olkiluoto waste repository, Finland, as part of the development of the Posiva Safety Case Portfolio. This project included a review of the development of international policies and standards related to protection of biota from the effects of ionizing radiation and of biota assessment methodologies, paying particular attention to those that have been applied to waste repository performance assessments. On the basis of this review, recommendations were developed on the most appropriate methodology to apply in order to assess the impact of radioactive releases from the planned spent fuel repository in Olkiluoto. A test-case was developed, in collaboration with staff from Posiva and Facilia AB, and an assessment was performed. The results and experience of which were analysed and summarised to develop recommendations for a future strategy. The test case highlighted some significant data gaps related to the assessment of impacts to both generic biota types and to interest species. In particular, concentration ratios for generic carnivorous mammals and migratory species such as moose that may consume food from multiple ecosystems and dose conversion factors for large burrowing (i.e. hibernating) mammals. However, in general terms, the dose rates predicted for all organism types were several orders of magnitude below those at which population effects would be expected to be observed and those at which effects on the individual may be anticipated. There would therefore be scope for simplifying the approach applied, although there would be value in performing a sensitivity analysis to ensure that the simplification is applied appropriately. There would also be value in ensuring consistency of the developing approach for non-human biota with

Immobilization of uranium in biofilm microorganisms exposed to groundwater seeps over granitic rock tunnel walls in Olkiluoto, Finland

Science.gov (United States)

Krawczyk-Bärsch, Evelyn; Lünsdorf, Heinrich; Pedersen, Karsten; Arnold, Thuro; Bok, Frank; Steudtner, Robin; Lehtinen, Anne; Brendler, Vinzenz

2012-11-01

In an underground rock characterization facility, the ONKALO tunnel in Finland, massive 5-10-mm thick biofilms were observed attached to tunnel walls where groundwater was seeping from bedrock fractures at a depth of 70 m. In laboratory experiments performed in a flow cell with detached biofilms to study the effect of uranium on the biofilm, uranium was added to the circulating groundwater (CGW) obtained from the fracture feeding the biofilm. The final uranium concentration in the CGW was adjusted to 4.25 × 10-5 M, in the range expected from a leaking spent nuclear fuel (SNF) canister in a future underground repository. The effects were investigated using microelectrodes to measure pH and Eh, time-resolved laser fluorescence spectroscopy (TRLFS), energy-filtered transmission electron microscopy (EF-TEM), and electron energy-loss spectroscopy (EELS) studies and thermodynamic calculations were utilized as well. The results indicated that the studied biofilms constituted their own microenvironments, which differed significantly from that of the CGW. A pH of 5.37 was recorded inside the biofilm, approximately 3.5 units lower than the pH observed in the CGW, due to sulfide oxidation to sulfuric acid in the biofilm. Similarly, the Eh of +73 mV inside the biofilm was approximately 420 mV lower than the Eh measured in the CGW. Adding uranium increased the pH in the biofilm to 7.27 and reduced the Eh to -164 mV. The changes of Eh and pH influenced the bioavailability of uranium, since microbial metabolic processes are sensitive to metals and their speciation. EF-TEM investigations indicated that uranium in the biofilm was immobilized intracellularly in microorganisms by the formation of metabolically mediated uranyl phosphate, similar to needle-shaped autunite (Ca[UO2]2[PO4]2·2-6H2O) or meta-autunite (Ca[UO2]2[PO4]2·10-12H2O). In contrast, TRLFS studies of the contaminated CGW identified aqueous uranium carbonate species, likely (Ca2UO2[CO3]3), formed due to the high

Regulatory aspects of Olkiluoto 3 nuclear power plant (EPR-1600) (Draft, 12 Sept. 2005)

International Nuclear Information System (INIS)

Sandberg, J.; Tiippana, P.

2005-01-01

A 1600 MWe European Pressurized Water Reactor (EPR) supplied by the Framatome ANP - Siemens Consortium is under construction at the Olkiluoto site in Finland. Current international safety requirements and especially French and German operating experience have been applied in the design. Finnish requirements and operating experience have also been applied, especially regarding site-specific features. Severe accidentmanagement and protection against a collision of a large passenger airplane are implemented in the plant design. The plant safety features, licensing procedure, Finnish regulatory requirements, changes to the original EPR design, project quality management and regulatory control are discussed. (author)

Stress evolution and fault stability at Olkiluoto during the Weichselian glaciation

International Nuclear Information System (INIS)

Lund, B.; Schmidt, P.

2011-06-01

In this study we investigate how a model of the Weichselian glacial cycle affects the state of stress in the Earth, and how those changes in stress influence the stability of faults. The main objectives for this study are the evolution of the glacially induced stresses at repository depth in Olkiluoto, Finland, and the stability field at seismogenic depths below the proposed repository. The analysis presented here is similar to the study by Lund et al. (2009) for the proposed Swedish nuclear waste repository sites of Forsmark and Oskarshamn. Along the lines of Lund et al. (2009), this study is a modeling study, where we use three-dimensional ice and earth models to calculate the glacial isostatic adjustment (GIA), i.e. the response of the Earth to an ice load, examining both displacements and stresses

Modelling of water-rock interaction at TVO investigation sites

International Nuclear Information System (INIS)

Pitkaenen, P.; Leino-Forsman, H.

1992-12-01

The geochemistry of the groundwater at the Kivetty, Syyry and Olkiluoto site investigation areas in Finland for nuclear waste disposal is evaluated. The hydrogeological data is collected from boreholes drilled down to 100-m depth into crystalline bedrock. The interpretation is based on groundwater chemistry and isotope data, mineralogical data, and the structure and hydrology of the bedrock, using correlation diagrams and the thermodynamic calculations (PHREEQE,EQ3NR). The hydrogeochemistry and major processes controlling the groundwater chemistry are discussed

An isotopic and fluid inclusion study of fracture calcite from borehole OL-KR1 at the Olkiluoto site, Finland

International Nuclear Information System (INIS)

Blyth, A.; Frape, S.; Blomqvist, R.; Nissinen, P.; McNutt, R.

1998-04-01

A study of the geochemistry of fracture filling calcite in borehole OL-KR1 at the radioactive waste disposal investigation site Olkiluoto (in Finland) was undertaken in 1998. The purpose of the present study is to characterize the fracture calcite using mineralogy, oxygen, carbon and strontium isotopes, and fluid inclusions in order to determine past and present chemical and isotopic condition at the site

An isotopic and fluid inclusion study of fracture calcite from borehole OL-KR1 at the Olkiluoto site, Finland

Energy Technology Data Exchange (ETDEWEB)

Blyth, A.; Frape, S. [Univ. of Waterloo, ON (Canada); Blomqvist, R.; Nissinen, P. [Geological Survey of Finland, Espoo (Finland); McNutt, R. [McMaster Univ. of Hamilton, ON (Canada)

1998-04-01

A study of the geochemistry of fracture filling calcite in borehole OL-KR1 at the radioactive waste disposal investigation site Olkiluoto (in Finland) was undertaken in 1998. The purpose of the present study is to characterize the fracture calcite using mineralogy, oxygen, carbon and strontium isotopes, and fluid inclusions in order to determine past and present chemical and isotopic condition at the site 39 refs.

A comprehensive summary of the ORNL Groundwater Compliance and Surveillance Sampling Results Software System

International Nuclear Information System (INIS)

Loffman, R.S.

1995-01-01

Groundwater compliance and surveillance activities are conducted at ORNL to fulfill federal and state requirements for environmental monitoring. Information management is an important aspect of this and encompasses many activities which usually have spcific time frames and schedules. In addition to fulfilling these immediate requirements, the results for the monitoring activities are also used to determine the need for environmental remediation. ORNL performs this groundwater results data management and reporting utilizing a group of SAS reg-sign applications and tools which provide the ability to track samples, capture field measurements, verify and validate result data, manage data, and report results in a variety of ways and in a timely manner. This paper provides a comprehensive summary of these applications and tools

In-situ failure test in the research tunnel at Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Autio, J.; Johansson, E.; Kirkkomaeki, T. [Saanio and Riekkola Consulting Engineers, Helsinki (Finland); Hakala, M. [Gridpoint Finland Oy (Finland); Heikkilae, E. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Rock Engineering

2000-05-01

A failure test suitable for execution in the Research Tunnel at Olkiluoto has been planned to study the failure of rock in-situ. The objectives of the in-situ failure test is to assess the applicability of numerical modelling codes and methods to the study of rock failure and associated crack propagation and to develop a novel technique to be used to determine the strength of rock in-situ. The objective of this study was to make a preliminary design of the failure test, assess the technical feasibility of the test and to give input information for further numerical modelling of the test. The design of the failure test is reported and results of preliminary modelling are given. The input information for future modelling includes a study of rock properties, fracture propagation in rock, in-situ stresses and the development of techniques for using the expanding agent to produce artificial stress field. The study showed that mechanical properties such as strength of gneissic tonalite, the main rock type in the Research Tunnel, depends highly on the orientation of schistocity. The in-situ failure test was shown to be technically feasible and a state of stress high enough to cause failure can be created artificially by using a proper expansive agent and design. (orig.)

Developing methodology for description of biosphere evolution at Olkiluoto disposal site utilising forest studies at other land uplift sites

International Nuclear Information System (INIS)

Ikondn, A.T.K.; Afo, L.

2004-01-01

In Finland, Olkiluoto Island has been selected as the site for final disposal of spent nuclear fuel, in addition to the existing repository for low and intermediate level waste. When creating biosphere models for safety assessments, local main features and processes need to be taken into account. A special characteristic of the site, as well as the coastal area of the Gulf of Bothnia in general, is the land uplift (6-9 mm/a). This continuously exposes new land to soil-formation processes and provides surfaces for colonization by plant communities. The forest vegetation succession on stony, fine-grained till soils starts from deciduous shoreline vegetation and ends in almost pure Norway spruce forests. This has enabled to study ecological and microbiological processes in soils and forests of different developmental stages, to monitor forest condition and the factors affecting it in sites locating close to each other. It has also made possible gradient studies of the succession of boreal mire ecosystems without a need to wait thousands of years. Applying a methodology described in the full paper, a descriptive model on the evolution of the biosphere will be established to indicate possible ecosystem distributions and main characteristics on the area on the basis of above-mentioned studies carried out by Finnish Forest Research Institute, and of results of the site investigations at Olkiluoto. In future, the evolution description will be used as a basis for selection of appropriate ecosystem modules and parameter values in the subsequent coupled assessment model systems. (author)

Modelling of the in situ stress state at Olkiluoto Site, Western Finland

International Nuclear Information System (INIS)

Valli, J.; Kuula, H.; Hakala, M.

2011-06-01

In order to determine the interaction of in situ stress and geological features at Olkiluoto with the ONKALO area under more specific focus, stress modelling work was launched in 2009. This entailed updating a previously used model geometry to suit current needs whilst also updating interpreted brittle deformation zones according to the data provided by Posiva in the beginning of 2010. The previous model geometry was originally used for seismic and glacial load simulations. Brittle deformation zones were updated in the model according to a new selection criterion which added a number of brittle deformation zones. Changes in the geometry of certain brittle deformation zones were also necessary to better fit the early 2010 interpretations from Posiva. Modelling goals were to clarify the effect of joint parameters on stress magnitude and orientation and which of the major brittle deformation zones detected in the ONKALO region could have potential effects on local in situ stress states. Additional goals included modelling the effect of several optional thrust boundary conditions and an ice-age. Compression from the northwest-southeast was used as the default approach whilst north-south, east-west and northeast-southwest were optional conditions. A simplified glaciation cycle was also simulated. Results were clear in demonstrating the critical effect of joint cohesion and joint friction angle, i.e. shear strength, on stress-geology interaction, essentially in this order of importance. The case that utilised both drillhole core-logging and ONKALO tunnel mapping results did not exhibit much if any stress-geology interactions as BFZ strength parameters were too high in order to allow any interactions to occur. The geometry and orientation of brittle deformation zones was found to be of significant importance; deformation zones with a shallow dip roughly in the direction of applied compression were optimal for causing stress rotations and the increase of stress magnitude

Will Jakarta Be The Next Atlantis? Excessive Groundwater Use Resulting From A Failing Piped Water Network

Directory of Open Access Journals (Sweden)

Nicola Colbran

2009-06-01

Full Text Available This article examines the connection between a failing piped water network and excessive groundwater use in Jakarta. It discusses the political history of the city's piped water network, which was privatised in 1998, and how privatisation was intended to increase access to clean, safe water for its residents. The article asserts that this has not eventuated, and that tap water remains costly, unreliable and does not provide noticeable benefits when compared with groundwater. The result is that households, industry, businesses, luxury apartment complexes and hotels choose alternative water sources and distribution methods, in particular groundwater. This is having an unsustainable impact on groundwater levels and Jakarta 's natural environment, causing significant land subsidence, pollution and salinisation of aquifers, and increased levels of flooding. The effect is so severe that the World Bank has predicted much of Jakarta will be inundated by seawater in 2025, rendering one third of the city uninhabitable and displacing millions. The article concludes by discussing and assessing the steps the government has taken to address excessive and unlicensed groundwater use. These steps include new regulations on groundwater, a public awareness campaign on the importance of groundwater and a commitment to improve the raw water supplied to the piped water network. However, the article observes that the government is yet to develop long term policies for improvement of the network itself. The question therefore remains, has the government done enough, or will groundwater use continue unabated making Jakarta the next lost city of Atlantis?

Groundwater monitoring in the archaeological site of Ostia Antica (Rome, Italy: first results

Directory of Open Access Journals (Sweden)

Lucia Mastrorillo

2016-06-01

Full Text Available The archaeological site of Ostia Antica hosts the ruins of the ancient roman city called Ostia founded in the VII century B.C. near the mouth of Tiber River. The area was strategically important for Rome, not only for the control of the river, but also for some salt marshes (Ostia Pound. During the XIX century, the whole area was reclaimed and the salt production stopped. Nowadays drainage canals and pumps avoid the flood of zones placed below sea level, keeping dewatering below the ground surface. In February 2014, the site was largely flooded after an exceptional rainfall event and the Superintendence for Archaeological Heritage of Rome ordered the closure for 15 days. Few months later (July 2014 a groundwater monitoring project started with the aim of studying the aquifer response to local rainfall and prevent future damage and groundwater flooding. The activity consisted in water-table monitoring, groundwater electrical conductivity (EC and temperature continuous measurements, coupled with chemical analysis of major ions. Preliminary results shows the link between water table fluctuations and rainfall distributions. The average elevation of the archaeological area is about 2,5 m a.s.l. and the local water-table depth is of about 0,5 m a.s.l.; groundwater flows from the Tiber River to the reclaimed area according to regional flowpath. Groundwater sampled from three wells is Ca-HCO3 freshwater (600 - 1000 μS/cm, while the sample collected from a well located close to ancient salt storage warehouse (now Ostia Antica museum, is Na-Cl brackish water (about 4000 μS/cm. The chemical evolution of groundwater from summer to winter suggested a possible lateral inflow from the Tiber River, affected by salt-wedge intrusion. The inflow of Ca-Cl, SO4 Tiber’s water with an intermediate salinity could determine salinization of Ca-HCO3 freshwaters and refreshing of Na-Cl brackish water.

Regional development of river basins in the Olkiluoto-Pyhaejaervi Area, SW Finland, 2000 BP - 8000 AP

International Nuclear Information System (INIS)

Ojala, A.E.K.; Virkki, H.; Palmu, J.-P.; Hokkanen, K.; Kaija, J.

2006-12-01

Biosphere assessment forms one of the main components in Posiva's Safety Case portfolio and includes analyses of terrain and ecosystem development. Shoreline displacement and changes in surface hydrology form one part of these analyses. In this report, the regional development of the Olkiluoto-Pyhaejaervi area in the time period 2000 BP - 8000 AP was examined by taking into account changes in the surface flow patterns of the Lapinjoki and Eurajoki river basins. A hydrological model, EULA, was developed and applied to investigate the past and future hydrological regimes and changes in the Olkiluoto-Pyhaejaervi study area. As detailed assessment of erosion and sedimentation effects were not within the scope of this study, only their general effects were evaluated. The digital elevation models (DEM) for different time stages (2000, 1500, 1000 and 500 BP; 100, 300, 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 6000, 7000 and 8000 AP) were compiled taking into account the land uplift and tilting of the Earth's crust. With the aid of various sophisticated GIS tools, the boundaries of the main river basins, the flow patterns of rivers and development of lakes during each stage were modelled. The yearly discharge rates of rivers Eurajoki and Lapinjoki were also evaluated with the assumption that present climatic features prevail during the whole time period 2000 BP - 8000 AP. Finally, the probability of significant changes in the surface water flow routes were estimated during different stages. (orig.)

Assessing groundwater policy with coupled economic-groundwater hydrologic modeling

Science.gov (United States)

Mulligan, Kevin B.; Brown, Casey; Yang, Yi-Chen E.; Ahlfeld, David P.

2014-03-01

This study explores groundwater management policies and the effect of modeling assumptions on the projected performance of those policies. The study compares an optimal economic allocation for groundwater use subject to streamflow constraints, achieved by a central planner with perfect foresight, with a uniform tax on groundwater use and a uniform quota on groundwater use. The policies are compared with two modeling approaches, the Optimal Control Model (OCM) and the Multi-Agent System Simulation (MASS). The economic decision models are coupled with a physically based representation of the aquifer using a calibrated MODFLOW groundwater model. The results indicate that uniformly applied policies perform poorly when simulated with more realistic, heterogeneous, myopic, and self-interested agents. In particular, the effects of the physical heterogeneity of the basin and the agents undercut the perceived benefits of policy instruments assessed with simple, single-cell groundwater modeling. This study demonstrates the results of coupling realistic hydrogeology and human behavior models to assess groundwater management policies. The Republican River Basin, which overlies a portion of the Ogallala aquifer in the High Plains of the United States, is used as a case study for this analysis.

Game statistics for the island of Olkiluoto in 2010-2011

International Nuclear Information System (INIS)

Nieminen, M.; Niemi, M.; Jussila, I.

2011-10-01

The game statistics for the island of Olkiluoto were updated in the summer 2011 and compared with earlier statistics. Population size estimates are based on interviews of the local hunters. No moose or deer inventories were made in the winter 2010-2011. The moose population is stable when compared with the previous year. The white-tailed deer population is stable or slightly increasing when compared with the previous year. The changes in the roe deer population are not accurately known, but population size varies somewhat from year to year. The number of hunted raccoon dogs approximately doubled in the latest hunting season. Altogether two waterfowl were hunted in 2010 (17 in the previous year). The populations of mountain hare and red squirrel are abundant, and the number of hunted mountain hares approximately doubled when compared with the previous hunting season. The brown hare population is still small. In the winter, there were observations of one lynx spending time in the area. (orig.)

Game statistics for the island of Olkiluoto in 2010-2011

Energy Technology Data Exchange (ETDEWEB)

Nieminen, M. [Faunatica Oy, Espoo (Finland); Niemi, M. [Helsinki Univ. (Finland), Dept. of Forest Sciences; Jussila, I. [Turku Univ. (Finland), Satakunta Environmental Research Inst.

2011-10-15

The game statistics for the island of Olkiluoto were updated in the summer 2011 and compared with earlier statistics. Population size estimates are based on interviews of the local hunters. No moose or deer inventories were made in the winter 2010-2011. The moose population is stable when compared with the previous year. The white-tailed deer population is stable or slightly increasing when compared with the previous year. The changes in the roe deer population are not accurately known, but population size varies somewhat from year to year. The number of hunted raccoon dogs approximately doubled in the latest hunting season. Altogether two waterfowl were hunted in 2010 (17 in the previous year). The populations of mountain hare and red squirrel are abundant, and the number of hunted mountain hares approximately doubled when compared with the previous hunting season. The brown hare population is still small. In the winter, there were observations of one lynx spending time in the area. (orig.)

Use of Geological Lineaments Results in Groundwater Exploration ...

African Journals Online (AJOL)

Locating aquifiers in Precambrian crystalline rocks offers major problems unless areas of intense weathering or fracturing are targeted. These normally occur along geological lineaments which can be identified during groundwater exploration. Major geological lineaments were identified in the Zomba area, southern Malawi ...

Groundwater-Quality Data in the Madera-Chowchilla Study Unit, 2008: Results from the California GAMA Program

Science.gov (United States)

Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth

2009-01-01

, oxygen, and carbon, and activities of tritium and carbon-14), and dissolved noble gases also were measured to help identify the sources and ages of the sampled groundwater. In total, approximately 300 constituents and field water-quality indicators were investigated. Three types of quality-control samples (blanks, replicates, and samples for matrix spikes) each were collected at approximately 11 percent of the wells sampled for each analysis, and the results obtained from these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that data for the groundwater samples were not compromised by possible contamination during sample collection, handling or analysis. Differences between replicate samples were within acceptable ranges. Matrix spike recoveries were within acceptable ranges for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, raw groundwater typically is treated, disinfected, or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to raw groundwater. However, to provide some context for the results, concentrations of constituents measured in the raw groundwater were compared with regulatory and non-regulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and the California Department of Public Health (CDPH), and with aesthetic and technical thresholds established by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only, and are not indicative of compliance or non-compliance with regulatory thresholds. The concentrations of most constituents detected in groundwater samples from MADCHOW wells were below drinking-water thresholds. Organic compounds (VOCs and pesticides

Core drilling of deep drillhole OL-KR47 at Olkiluoto in Eurajoki 2007-2008

International Nuclear Information System (INIS)

Toropainen, V.

2008-02-01

As a part of the confirming site investigations for ONKALO rock characterisation facility, Suomen Malmi Oy (Smoy) core drilled 1008.76 m and 44.31 m deep drillholes with a diameter of 75.7 mm at Olkiluoto in October 2007 - January 2008. The identification numbers of the drillholes are OL-KR47 and OL-KR47B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the returning and drilling waters were recorded. The drill rig was computer controlled and during drilling the computer recorded drilling parameters. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The total volumes of the used drilling and flushing water were 1229 m 3 and 13.6 m 3 in drillholes OL-KR47 and OL-KR47B, respectively. Measured volume of the returning water in drillhole OL-KR47 was 1125 m 3 , water did not return in drillhole OL-KR47B. The deviation of the drillholes was measured with the deviation measuring instruments EMS and Maxibor II. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is 92.1 MPa, the average Young's Modulus is 32.5 GPa and the average Poisson's ratio is 0.33. The main rock types are diatexitic and veined gneisses, pegmatitic granite and tonaliticgranodioritic- granitic gneiss. The average fracture frequency is 2.2 pcs / m in drillhole OL-KR47 and 3.4 pcs / m in drillhole OL-KR47B. The average RQD values were 95.3 % and 94.1 %. In drillhole OL-KR47 46 fractured zones and in drillhole OL-KR47B two fractured zones were penetrated during drilling work. (orig.)

Economic Development Threatens Groundwater in Puerto Rico: Results of a Field Study.

Science.gov (United States)

Arbona, Sonia I.; Hunter, John M.

1995-01-01

Presents the results of a field study done on 7 wells providing 37% of the total aquifer production for 4 municipalities in Puerto Rico. Each sampled well showed signs of contamination by heavy metals, nitrate, and semivolatile organic compounds. Although found in low concentrations, current development threatens groundwater quality. (MJP)

Aeromagnetic survey in Eurajoensalmi, Olkiluoto 2008

International Nuclear Information System (INIS)

Levaeniemi, H.

2008-08-01

This report describes the survey operation, survey and processing methods and the deliverables of an aerogeophysical survey in Olkiluoto area in April 2008. The survey was conducted by Geological Survey of Finland (GTK). The survey aircraft was a twin-engine Twin Otter operated by Finnish Aviation Academy (SIO) and owned by Natural Environment Research Council / British Geological Survey (NERC / BGS), with whom GTK has established a joint venture called Joint Airborne-geoscience Capability (JAC). The survey was conducted in April 2008 during six days. The survey consists of six separate survey flights, one of which was a magnetic calibration flight. The survey was based in Pori airport. Survey line spacing was 50 meters and nominal survey altitude was 30 meters. Measurements were completed in April 2008, and data processing and reporting was done in June 2008. Two cesium magnetometers installed onboard the aircraft (at the left wingtip and in a nose cone) were measuring the magnetic total field intensity during the survey flights. An automatic compensation unit corrected the aircraft attitude errors in the magnetic data in real time. In addition to magnetic measurement, auxiliary parameters such as flight altitude and aircraft attitude were also recorded simultaneously. Reference ground base station was used for recording the temporal variations in the magnetic field and also reference data for post-positioning of coordinate information. In the post-processing phase, heading correction, base station correction and microlevelling procedures were applied to the magnetic data. The data was exported to numeric XYZ files and interpolated into grid data file. A noteworthy local detail present in the survey and in the processing was the massive power line. For safety reasons, flight altitude had to be increased and survey lines had to be cut short in the vicinity of the powerline. However, due to reasonable planning of the survey area boundaries, this caused no great

Results of RCRA groundwater quality assessment at the 216-B-3 Pond Facility

International Nuclear Information System (INIS)

Barnett, D.B.; Teel, S.S.

1997-06-01

This document describes a groundwater quality assessment of the 216-B-3 pond system, a Resources Conservation and Recovery act of 1976 (RCRA) waste facility. In 1990, sampling and chemical analysis of groundwater underlying the facility indicated that the contamination indicator parameters, total organic halogens (TOX), and total organic carbon (TOC) had exceeded established limits in two wells. This discovery placed the facility into RCRA groundwater assessment status and subsequently led to a more detailed hydrochemical analysis of groundwater underlying the facility. Comprehensive chemical analyses of groundwater samples from 1994 through 1996 revealed one compound, tris (2-chloroethyl) phosphate (TRIS2CH), that may have contributed to elevated TOX concentrations. No compound was identified as a contributor to TOC. Detailed evaluations of TOX, TOC, and TRIS2CH and comparison of occurrences of these parameters led to conclusions that (1) with few exceptions, these constituents occur at low concentrations below or near limits of quantitation; (2) it is problematic whether the low concentrations of TRIS2CH represent a contaminant originating from the facility or if it is a product of well construction; and (3) given the low and diminishing concentration of TOX, TOC, and TRIS2CH, no further investigation into the occurrent of these constituents is justified. Continued groundwater monitoring should include an immediate recalculation of background critical means of upgradient/downgradient comparisons and a return to seminannual groundwater monitoring under a RCRA indicator parameter evaluation program

The geological and structural characterization of the Olkiluoto site in a critical perspective

International Nuclear Information System (INIS)

Cosgrove, J.; Jokinen, J.; Siivola, J.; Tiren, S.

2003-05-01

This report comments on aspects of Posiva's work relating to the interests of the IMGS (Investigations and Modelling of Geological Structures) Group who is concerned with the potential impact of the tectonic and geological setting of the Olkiluoto site, on the construction a deep repository for spent nuclear fuel. Since the Group's last report (IMGS 2002) a variety of relevant publications have been produced by Posiva. A number of issues have been identified in these documents relating to the procedure for updating the Bedrock model, factors influencing the location and layout of ONKALO, the mapping procedure planned for the access tunnel, the problem of oversimplification and uncertainties and the proposed extension of the repository. These are discussed in the present report. (orig.)

Groundwater Quality Data for the Northern Sacramento Valley, 2007: Results from the California GAMA Program

Science.gov (United States)

Bennett, Peter A.; Bennett, George L.; Belitz, Kenneth

2009-01-01

to 11 percent of the wells, and the results for these samples were used to evaluate the quality of the data obtained from the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a noticeable source of bias in the data for the groundwater samples. Differences between replicate samples were within acceptable ranges for nearly all compounds, indicating acceptably low variability. Matrix-spike recoveries were within acceptable ranges for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, raw groundwater typically is treated, disinfected, or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw groundwater were compared with regulatory and nonregulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH) and with aesthetic and technical thresholds established by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only and do not indicate compliance or noncompliance with those thresholds. The concentrations of most constituents detected in groundwater samples from REDSAC were below drinking-water thresholds. Volatile organic compounds (VOC) and pesticides were detected in less than one-quarter of the samples and were generally less than a hundredth of any health-based thresholds. NDMA was detected in one grid well above the NL-CA. Concentrations of all nutrients and trace elements in samples from REDSAC wells were below the health-based thresholds except those of arsenic in three samples, which were above the USEPA maximum contaminant level (MCL-US). However

ONKALO 3D tunnel seismic investigations at Olkiluoto in 2009

International Nuclear Information System (INIS)

Cosma, C.; Enescu, N.; Balu, L.; Jacome, M.

2011-02-01

POSIVA Oy conducts bedrock investigations at the spent nuclear fuel final disposal site at Olkiluoto, in western Finland. The excavation of the access tunnel to the repository hosts the ONKALO underground rock characterization facility. The investigations carried out at ONKALO focus on the bedrock and groundwater conditions prevailing on the final disposal site and how construction work affects them. Tunnel seismic investigations were carried out in July 2009, as an extension of similar work performed in December 2007. The main objective of the tunnel seismic investigations have been to demonstrate the possibility to detect, locate and image cost effectively steeply and gently dipping fractures, at the side and/or below the tunnel and to characterize the volume of rock surrounding a 250 m long segment of the ONKALO tunnel. The survey was conducted at a depth of 350 m, over a 240 m long line of 3-components receivers, spaced at 3m intervals. Seismic signals were produced along two lines, on the tunnel wall and floor, with source points spaced at 1m. A timedistributed swept-impact, the Vibsist-250 hydraulic source, was used. The source was hosted on a mini excavator. Receiver holes approximately 0.4 m deep were drilled prior to the survey, horizontally into the tunnel wall. One of the procedures used for data stacking and migration is based on a proprietary method combining the DMO (Dip Move Out) correction and an expression of the Radon Transform. Horizontal and vertical migrated profiles were computed both for the P wave and S wave reflected wave fields. A true 3D migration technique (Image Point migration) was used to create 3D migrated sections oriented to incremental azimuths around the tunnel, the result being a cylindrical imaging volume. A general conclusion is that seismic surveys along the tunnel can economically be used for rock mass characterization. High quality results can be obtained by operations in tunnel working conditions, provided that due

Focused modelling. Fracture identification in Olkiluoto borehole OL-KR04

International Nuclear Information System (INIS)

Jokinen, J.; Jakobsson, K.

2004-10-01

An extensive set of measured borehole data has been obtained from geological repository investigations in the bedrock of Olkiluoto. Our hypothesis is that geophysical data may be used more efficiently to identify and classify fracture zones. It is known that several geophysical logging methods yield useful information outside the borehole walls that cannot be reached otherwise. At present, this data is used for additional fracture characterization but not for identification purposes. The study focuses on the application of 14 different geophysical data measured in the borehole OL-KR04. The whole data set is divided into main groups using the Principal Component Analysis (PCA). Each group is composed mainly of sensitive methods detecting specific physical characteristics. The main groups from the geophysical point of view are open fractures, reduced density, increased electrical conductivity, and increased natural radiation. The Varimax optimization method is used to maximize the importance of supporting data as well as to emphasize differences between the discovered principal components. In fracture zone analysis, drilling core samples and the hydrological measurement results form an indispensable data set. For practical reasons, and in order to fulfill the requirements of the PCA analysis, S-wave velocity and electrical resistivity measurements are also performed. A combination of these methods, simultaneously applied using suitable 'trigger limits', identifies penetrated extensive fracture sections in a borehole cost-effectively and unambiguously. (orig.)

Summary of the results and interpretation of tritium and noble gas measurements on groundwater samples from the Perch Lake Basin Area

International Nuclear Information System (INIS)

Kotzer, T.G.

1999-02-01

Along the west-central margin of the Lower Perch Lake Basin, a limited number of groundwaters have been sampled from piezometers at depths of between 8 and 17 m and distances of between 100 and 900 m downgradient from their recharge location near Area A. Concentrations of tritium in these groundwaters varied between approximately 100 and 2800 TU. Measurements of dissolved gases in these groundwaters indicate concentrations of 4 He and neon approximating those in recently recharged groundwaters; however, the concentrations of 3 He are as much as 100 times higher, indicating the waters have accumulated tritiogenic 3 He. Using the 3 H/ 3 He dating technique, groundwater residence times on the order of 29 ± 8 years and groundwater velocities on the order of 0.1 m/day have been calculated for the flow system in the middle sand unit between Area A recharge and Perch Lake. These results, although based on a very small number of groundwater analyses, are comparable to earlier estimates of groundwater residence times and velocities obtained using Darcy calculations, borehole dilution experiments and tracer-test results from previous hydrogeologic studies in the area. (author)

Geochemical modelling of groundwater evolution and residence time at the Haestholmen site

Energy Technology Data Exchange (ETDEWEB)

Pitkaenen, P.; Luukkonen, A. [VTT Communities and Infrastructure, Espoo (Finland); Ruotsalainen, P. [Fintact Oy, Helsinki (Finland); Leino- Forsman, H.; Vuorinen, U. [VTT Chemical Technology, Espoo (Finland)

2001-01-01

An understanding of the geochemical evolution of groundwater is an essential part of the performance assessment and safety analysis of the geological final disposal of radioactive waste. The performance of technical barriers and migration of possibly released radionuclides depend on the geochemical conditions. A prerequisite for understanding these factors is the ability to specify the water-rock interactions that control chemical conditions in groundwater. The objective of this study is to interpret the processes and factors that control the hydrogeochemistry, such as pH and redox conditions. A model of the hydrogeochemical progress in different parts of the crystalline bedrock at Haestholmen has been created and the significance of geochemical reactions and groundwater mixing along different flow paths calculated. Long term hydrodynamics have also been evaluated. The interpretation and modelling are based on water samples (64 altogether) obtained from precipitation, the Baltic Sea, the soil layer, shallow wells in the bedrock, and 14 deep boreholes in the bedrock for which a comprehensive data set on dissolved chemical species and isotopes was available. Some analyses of dissolved gases and their isotopic measurements were also utilised. The data covers the bedrock at Haestholmen to a depth of 1000 m. The results from groundwater chemistry, isotopes, petrography, hydrogeology of the site, geomicrobial studies, and PCA and speciation calculations were used to evaluate evolutionary processes at the site. The geochemical interpretation of water-rock interaction, isotope-chemical evolution ({delta}{sup 13}C and {delta}{sup 34}S) and mixing of palaeo-water types were approached by mass-balance calculations (NETPATH). Reaction-path calculations (EQ3/6) were used to verify the thermodynamic feasibility of the reaction models obtained. The interpretation and calculation of hydrochemical data from Haestholmen suggest that changes in external conditions, such as glaciation

Comparison of a Conceptual Groundwater Model and Physically Based Groundwater Mode

Science.gov (United States)

Yang, J.; Zammit, C.; Griffiths, J.; Moore, C.; Woods, R. A.

2017-12-01

Groundwater is a vital resource for human activities including agricultural practice and urban water demand. Hydrologic modelling is an important way to study groundwater recharge, movement and discharge, and its response to both human activity and climate change. To understand the groundwater hydrologic processes nationally in New Zealand, we have developed a conceptually based groundwater flow model, which is fully integrated into a national surface-water model (TopNet), and able to simulate groundwater recharge, movement, and interaction with surface water. To demonstrate the capability of this groundwater model (TopNet-GW), we applied the model to an irrigated area with water shortage and pollution problems in the upper Ruamahanga catchment in Great Wellington Region, New Zealand, and compared its performance with a physically-based groundwater model (MODFLOW). The comparison includes river flow at flow gauging sites, and interaction between groundwater and river. Results showed that the TopNet-GW produced similar flow and groundwater interaction patterns as the MODFLOW model, but took less computation time. This shows the conceptually-based groundwater model has the potential to simulate national groundwater process, and could be used as a surrogate for the more physically based model.

Establishing baseline conditions and monitoring during construction of the Olkiluoto URCF access ramp

International Nuclear Information System (INIS)

Miller, B.; Arthur, J.; Bruno, J.; Hooker, P.; Richardson, P.; Robinson, C.; Arcos, D.; West, J.

2002-12-01

Posiva have identified Olkiluoto as the candidate site for the Finnish spent fuel repository. As part of the necessary site investigations, an underground rock characterisation facility (URCF), named ONKALO, is planned to be built. Construction of ONKALO will begin with construction of an inclined ramp. This will disturb the surrounding rock mass and groundwater systems and, as a consequence, a variety of physical, chemical, hydrogeological and biological processes will occur in response. Some of these processes will be important for understanding the site and the longterm performance of the future repository, should it be built, whilst others will be of secondary importance. This report identified, using expert judgment, 54 processes which could be induced in the subsurface as a result of ramp construction. These processes were then described and categorised according to the expected spatial and temporal scales of their impacts, as well as for their significance. Of these processes, 24 are considered to be of high significance for site understanding but only 12 are considered to be of high significance for repository performance. These processes are the primary ones the monitoring programme should endeavour to characterise during construction. The remaining processes may also be included in the monitoring programme but they are of lesser importance. An estimation of the spatial scales over which these high significance processes may occur suggests that, in most cases, they would be limited to the <1 (local) to 10 m (site) range. Many, particularly geochemical and biological processes, are likely to be restricted to a zone adjacent to the tunnel walls only a few 10's of centimetres thick due to the very low hydraulic conductivity of the rock mass. Some physical and hydrogeological processes may, however, impact on a larger volume of the rock, up to 100 m from the tunnel in response to changes to the stress field and pumping of groundwater. An estimation of the

Numerical simulation of groundwater flow in LILW Repository site:I. Groundwater flow modeling

Energy Technology Data Exchange (ETDEWEB)

Park, Koung Woo; Ji, Sung Hoon; Kim, Chun Soo; Kim, Kyoung Su [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Ji Yeon [Korea Hydro and Nuclear Power Co. Ltd., Seoul (Korea, Republic of)

2008-12-15

Based on the site characterization works in a low and intermediate level waste (LILW) repository site, the numerical simulations for groundwater flow were carried out in order to understand the groundwater flow system of repository site. To accomplish the groundwater flow modeling in the repository site, the discrete fracture network (DFN) model was constructed using the characteristics of fracture zones and background fractures. At result, the total 10 different hydraulic conductivity(K) fields were obtained from DFN model stochastically and K distributions of constructed mesh were inputted into the 10 cases of groundwater flow simulations in FEFLOW. From the total 10 numerical simulation results, the simulated groundwater levels were strongly governed by topography and the groundwater fluxes were governed by locally existed high permeable fracture zones in repository depth. Especially, the groundwater table was predicted to have several tens meters below the groundwater table compared with the undisturbed condition around disposal silo after construction of underground facilities. After closure of disposal facilities, the groundwater level would be almost recovered within 1 year and have a tendency to keep a steady state of groundwater level in 2 year.

Review of the GPS deformation monitoring studies commissioned by Posiva Oy on the Olkiluoto, Kivetty and Romuvaara sites, 1994-2000

International Nuclear Information System (INIS)

Vermeer, M.

2002-05-01

This report reviews the work done by scientists from the Finnish Geodetic Institute at the three sites Olkiluoto, Kivetty and Romuvaara over the years 1994-2000, with a view to detecting and measuring possible local crustal movements by means of geodetic GPS. The work, which consisted of measurements, computations and analysis, was reported in seven technical reports of Posiva Oy. Reviewed was also the work related to the three permanent stations established in these three sites, which have operated as part of the twelve-station national FinnRef network. The conclusion was that on the whole, the work has been performed professionally using state of the art equipment, measurement and analysis techniques by competent and experienced personnel. A number of suggestions for improvement and future work are given, mainly concerning the way the modelling of atmospheric propagation effects was done and how that affects the scale of the network computation, a proposal for monitoring the absolute scale, as well as remarks concerning the regular re-measurement of reserve marker ties, and the importance of continuing monitoring for a full solar activity cycle. The importance of interdisciplinarity is stressed. This review report is an outcome of the Bedrock Movements Investigations Group which supports STUKs regulatory activities related to confirming site investigations at Olkiluoto. (orig.)

Groundwater Quality Data for the Tahoe-Martis Study Unit, 2007: Results from the California GAMA Program

Science.gov (United States)

Fram, Miranda S.; Munday, Cathy; Belitz, Kenneth

2009-01-01

results obtained from these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that data for the groundwater samples were not compromised by possible contamination during sample collection, handling or analysis. Differences between replicate samples were within acceptable ranges. Matrix spike recoveries were within acceptable ranges for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, raw water typically is treated, disinfected, or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to raw groundwater. However, to provide some context for the results, concentrations of constituents measured in the raw groundwater were compared with regulatory and nonregulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and the California Department of Public Health (CDPH), and with aesthetic and technical thresholds established by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only and do not indicate of compliance or noncompliance with regulatory thresholds. The concentrations of most constituents detected in groundwater samples from the Tahoe-Martis wells were below drinking-water thresholds. Organic compounds (VOCs and pesticides) were detected in about 40 percent of the samples from grid wells, and most concentrations were less than 1/100th of regulatory and nonregulatory health-based thresholds, although the conentration of perchloroethene in one sample was above the USEPA maximum contaminant level (MCL-US). Concentrations of all trace elements and nutrients in samples from grid wells were below regulatory and nonregulatory health-based thresholds, with five exceptions. Concentra

Groundwater-Quality Data in the Antelope Valley Study Unit, 2008: Results from the California GAMA Program

Science.gov (United States)

Schmitt, Stephen J.; Milby Dawson, Barbara J.; Belitz, Kenneth

2009-01-01

-control samples (blanks, replicates, and samples for matrix spikes) were collected at 12 percent of the wells, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a noticeable source of bias in the data for the groundwater samples. Differences between replicate samples generally were within acceptable ranges, indicating acceptably low variability. Matrix spike recoveries were within acceptable ranges for most compoundsThis study did not evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to raw groundwater. However, to provide some context for the results, concentrations of constituents measured in the raw groundwater were compared with regulatory and non-regulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH) and thresholds established for aesthetic concerns (secondary maximum contaminant levels, SMCL-CA) by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only, and are not indicative of compliance or non-compliance with drinking water standards. Most constituents that were detected in groundwater samples were found at concentrations below drinking-water thresholds. Volatile organic compounds (VOCs) were detected in about one-half of the samples and pesticides detected in about one-third of the samples; all detections of these constituents were below health-based thresholds. Most detections of trace elements and nutrients in samples from ANT wells were below health-based thresholds. Exceptions include: one detection of nitrite plus nitr

Groundwater-Quality Data in the Colorado River Study Unit, 2007: Results from the California GAMA Program

Science.gov (United States)

Goldrath, Dara A.; Wright, Michael T.; Belitz, Kenneth

2010-01-01

approximately 30 percent of the wells, and the results were used to evaluate the quality of the data obtained from the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a significant source of bias in the data. Differences between replicate samples were within acceptable ranges and matrix-spike recoveries were within acceptable ranges for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, raw groundwater typically is treated, disinfected, or blended with other waters to maintain acceptable water quality. Regulatory thresholds apply to water that is served to the consumer, not to raw groundwater. However, to provide some context for the results, concentrations of constituents measured in the raw groundwater were compared to regulatory and nonregulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and the California Department of Public Health (CDPH) and to thresholds established for aesthetic concerns by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only and do not indicate compliance or noncompliance with those thresholds. The concentrations of most constituents detected in groundwater samples were below drinking-water thresholds. Volatile organic compounds (VOC) were detected in approximately 35 percent of grid well samples; all concentrations were below health-based thresholds. Pesticides and pesticide degradates were detected in about 20 percent of all samples; detections were below health-based thresholds. No concentrations of constituents of special interest or nutrients were detected above health-based thresholds. Most of the major and minor ion constituents sampled do not have health-based thresholds; the exception is chloride. Concentrations of chloride, sulfate, and total dis

Geochemistry and isotope hydrology of groundwaters in the Stripa Granite: results and preliminary interpretation

International Nuclear Information System (INIS)

Fritz, P.; Barker, J.F.; Gale, J.E.

1979-04-01

The results of geochemical and isotopic analyses on water samples from the granite at Stripa, Sweden, are presented. Groundwater samples collected from shallow, private wells; surface boreholes; and boreholes drilled from the 330 m and 410 m mine levels were analyzed for their major ion chemistry, dissolved gases, and environmental isotope contents. The principal change in the chemical load with depth is typified by chloride concentration, which increases from less than 5 mg/liter to about 300 mg/liter. There is a parallel increase in pH, which changes from about 6.5 to over 9.75. It is important to notice that calcite saturation is maintained and that, because of rising pH, dissolved inorganic carbon is lost. The total carbonate content thus decreases from about 70 mg/liter to less than 7 mg/liter. The 18 O and deuterium analyses demonstrate that different fracture systems contain different water masses, whose age increases with depth. Groundwater age determinations with 14 C and isotopes of the uranium decay series strongly indicate that water ages exceed 25,000 years. The 13 C contents of the aqueous carbonate in these groundwaters indicate groundwater recharge through vegetated soil, presumably during an interglacial period. The 13 C and 18 O determinations show that most fracture calcites have formed in a wide variety of depositional environments, and not in the waters circulating today

Laboratory testing of gneissic rocks in Olkiluoto borehole OL-KR24

International Nuclear Information System (INIS)

Eloranta, P.

2006-10-01

The stress-strain behaviour of anisotropic gneissic rocks from Olkiluoto, Finland, was studied for a total of 25 rock mechanics tests. Samples were selected from borehole OLKR24 at a depth level of 417-442 m. Tests included 15 uniaxial compression tests, 10 indirect tensile strength tests and 6 triaxial compression tests. Strain gauges were installed in five samples to evaluate the anisotropic properties, and acoustic emission sensors were installed in ten samples to estimate the stress damage levels. The specimen preparation and tests were carried out at the Laboratory of Rock Engineering, Helsinki University of Technology, Finland. Specimens were tested under laboratory-air-dry conditions and were photographed before and after the tests. The values obtained for the uniaxial compressive strength were in the range 56.5 - 165.9 MPa and for the indirect tensile strength 7.7 - 12.1 MPa. The anisotropic ratio of Young's modulus, E/E', was of the order of 1.1. (orig.)

Borehole plugging experiment in OL-KR24 at Olkiluoto, Finland

International Nuclear Information System (INIS)

Rautio, T.

2006-04-01

Sealing of investigation boreholes has been studied by Svensk Koernbroenslehantering AB (SKB) and Posiva Oy (Posiva) as a part of final disposal research. The proposed principle is that investigation boreholes drilled at a site must not act as a continuous flow path for groundwater but be sealed to become as tight as the surrounding rock. As a part of the investigations SKB and Posiva started the third phase of the joint project 'Cleaning and sealing of investigation boreholes' in 2005. One of the sub-projects was the plugging experiment in borehole OL-KR24 at Olkiluoto. The aim of the experiment was to test all main procedures of borehole sealing concept in practise in a deep borehole. Borehole KR24 was drilled to the depth of 551.11 metres in 2003 and it was located inside the shaft profile in Onkalo. From the surface to the depth of about 120 m the borehole diameter is 98 mm. The rest of the borehole is 75.7 mm in diameter. The borehole is vertical and the inclination is quite accurately 90 degrees. The plugging experiment in borehole OL-KR24 consisted of four main activities: (1) cleaning of the borehole, (2) characterization of the borehole (3) selective stabilisation of the borehole, and (4) emplacement of plugs. The comprehensive cleaning of the borehole was to be done in the first stage to provide the basis for other activities. The aim of characterization was to study the borehole in order to determine the sections for selective stabilisation and the locations for plugs. The characterization phase consisted of caliper measurements, dummy probing and optical borehole imaging (OBI). The aim of selective stabilisation was to show that selected borehole sections can be stabilised using new techniques and methods. One borehole section was reamed from Ω 76 mm to Ω 98 mm. The reamed borehole section should have been filled with sufficient amount of cement-based material to achieve a stable 'concrete tube' after redrilling, but due to encountered problems and

Estimating Groundwater Development area in Jianan Plain using Standardized Groundwater Index

Science.gov (United States)

Yu, Chang Hsiang; Haw, Lee Cheng

2017-04-01

Taiwan has been facing severe water crises in recent years owing to the effects of extreme weather conditions. Changes in precipitation patterns have also made the drought phenomenon increasingly prominent, which has indirectly affected groundwater recharge. Hence, in the present study, long-term monitoring data were collected from the study area of the Jianan plain. The standardized groundwater index (SGI) and was then used to analyse the region's drought characteristics. To analyse the groundwater level by using SGI, making SGI180 groundwater level be the medium water crises, and SGI360 groundwater level be the extreme water crises. Through the different water crises signal in SGI180 and SGI360, we divide groundwater in Jianan plain into two sections. Thereby the water crises indicators establishing groundwater level standard line in Jianan Plain, then using the groundwater level standard line to find the study area where could be groundwater development area in Jianan plain. Taking into account relatively more water scarcity in dry season, so the study screen out another emergency backup groundwater development area, but the long-term groundwater development area is still as a priority development area. After finding suitable locations, groundwater modeling systems(GMS) software is used to simulate our sites to evaluate development volume. Finally, the result of study will help the government to grasp the water shortage situation immediately and solve the problem of water resources deployment.

Groundwater-quality data for the Sierra Nevada study unit, 2008: Results from the California GAMA program

Science.gov (United States)

Shelton, Jennifer L.; Fram, Miranda S.; Munday, Cathy M.; Belitz, Kenneth

2010-01-01

Nevada study unit: granitic, metamorphic, sedimentary, and volcanic rocks. One natural spring that is not used for drinking water was sampled for comparison with a nearby primary grid well in the same cell. Groundwater samples were analyzed for organic constituents (volatile organic compounds [VOC], pesticides and pesticide degradates, and pharmaceutical compounds), constituents of special interest (N-nitrosodimethylamine [NDMA] and perchlorate), naturally occurring inorganic constituents (nutrients, major ions, total dissolved solids, and trace elements), and radioactive constituents (radium isotopes, radon-222, gross alpha and gross beta particle activities, and uranium isotopes). Naturally occurring isotopes and geochemical tracers (stable isotopes of hydrogen and oxygen in water, stable isotopes of carbon, carbon-14, strontium isotopes, and tritium), and dissolved noble gases also were measured to help identify the sources and ages of the sampled groundwater. Three types of quality-control samples (blanks, replicates, and samples for matrix spikes) each were collected at approximately 10 percent of the wells sampled for each analysis, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination from sample collection, handling, and analytical procedures was not a significant source of bias in the data for the groundwater samples. Differences between replicate samples were within acceptable ranges, with few exceptions. Matrix-spike recoveries were within acceptable ranges for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, groundwater typically is treated, disinfected, or blended with other waters to maintain water quality. Regulatory benchmarks apply to finished drinking water that is served to the consumer, not to untre

Aerogeophysical survey in Olkiluoto 2009

International Nuclear Information System (INIS)

Kurimo, M.

2009-08-01

This report describes the survey operation, survey and processing methods and the deliverables of an aerogeophysical survey in Olkiluoto area in May 2009. The survey was conducted by Geological Survey of Finland (GTK). The survey aircraft was a twin-engine Twin Otter operated by Finnish Aviation Academy (SIO) and owned by Natural Environment Research Council / British Geological Survey (NERC / BGS), with whom GTK has established a joint venture called Joint Airborne-geoscience Capability (JAC). The survey was conducted in May 2009 between May 5th and May 18th. The survey consists of ten separate survey flights and two magnetic calibration flights. The survey was based in Pori airport. Survey line spacing was 50 meters and nominal survey altitude was 30 meters. Measurements were completed in May 2009, and data processing and reporting was done in June 2009. Two cesium magnetometers installed onboard the aircraft (at the left wingtip and in a nose cone) were measuring the magnetic total field intensity during the survey flights. An automatic compensation unit corrected the aircraft attitude errors in the magnetic data in real time. The four-frequency electromagnetic (EM) unit included four transmitter coils with amplifiers in right wingtip and four receiver coils in left wingtip. Frequencies were 900 Hz, 3 kHz, 14 kHz and 24.5 kHz. The gamma spectrometer with two crystal packages (total volume 42 litres) measured the 256 channel energy spectra. In addition, auxiliary parameters such as flight altitude and aircraft attitude were also recorded simultaneously. Reference ground base station was used for recording the temporal variations in the magnetic field and also reference data for post-positioning of coordinate information. In the post-processing phase, heading correction, base station correction and microlevelling procedures were applied to the magnetic data. The EM data and radiometric data were corrected with calibration coefficients and levelled. The data was

Nitrate and ammonia as nitrogen sources for deep subsurface microorganisms

Directory of Open Access Journals (Sweden)

Heini eKutvonen

2015-10-01

Full Text Available We investigated the N-utilizing bacterial community in anoxic brackish groundwater of the low and intermediate level nuclear waste repository cave in Olkiluoto, Finland, at 100 m depth using 15N-based stable isotope probing (SIP and enrichment with 14/15N-ammonium or 14/15N-nitrate complemented with methane. 28 days of incubation at 12°C increased the concentration of bacterial 16S rRNA and nitrate reductase (narG gene copies in the substrate amended microcosms simultaneously with a radical drop in the overall bacterial diversity and OTU richness. Hydrogenophaga/Malikia were enriched in all substrate amended microcosms and Methylobacter in the ammonium and ammonium+methane supplemented microcosms. Sulfuricurvum was especially abundant in the nitrate+methane treatment and the unamended incubation control. Membrane-bound nitrate reductase genes (narG from Polarimonas sp. were detected in the original groundwater, while Burkholderia, Methylibium and Pseudomonas narG genes were enriched due to substrate supplements. Identified amoA genes belonged to Nitrosomonas sp. 15N-SIP revealed that Burkholderiales and Rhizobiales clades belonging to the minority groups in the original groundwater used 15N from ammonium and nitrate as N source indicating an important ecological function of these bacteria, despite their low number, in the groundwater N cycle in Olkiluoto bedrock system.

Geophysical borehole logging and optical imaging of the boreholes KR34, KR35 and KR36, at Olkiluoto 2005

International Nuclear Information System (INIS)

Majapuro, J.

2005-09-01

Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of the boreholes KR34, KR35 and KR36 at the Olkiluoto site in Eurajoki during May - June 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all surveys, interpretation and processing of the acoustic and borehole radar data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

Geophysical borehole logging and optical imaging of the boreholes KR34, KR35 and KR36, at Olkiluoto 2005

Energy Technology Data Exchange (ETDEWEB)

Majapuro, J. [Suomen Malmi Oy, Espoo (Finland)

2005-09-15

Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of the boreholes KR34, KR35 and KR36 at the Olkiluoto site in Eurajoki during May - June 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all surveys, interpretation and processing of the acoustic and borehole radar data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

Groundwater monitoring at three Oak Ridge National Laboratory inactive waste impoundments: results after one year

Energy Technology Data Exchange (ETDEWEB)

Francis, C. W.; Stansfield, R. G.

1986-10-01

To determine if the migration of potential contaminants from three inactive waste impoundments at Oak Ridge National Laboratory poses a threat to groundwater quality, at least one upgradient groundwater monitoring well and threee downgradient monitoring wells were installed at each impoundment in early 1985. These three unlined impoundments, formerly used to collect and, in some instances, treat wastewater are: the 3513 impoundment; the Old Hydrofracture Facility (OHF) impoundment; and the Homogeneous Reactor Experimnt No. 2 impoundment. Groundwater samples were collected quarterly for one year. Analyses were conducted for the groundwater protection parameters promulgated by the Resource Conservation and Recovery Act. The groundwater samples were also analyzed for polychlorinated biphenyls, copper, nickel, zinc, /sup 90/Sr, /sup 137/Cs, and tritium. The contaminants found most often to affect groundwater quality at all three waste impoundments were radionuclides. For example, mean concentrations of gross beta and gross alpha activity exceeded drinking water limits at all three sites. The gross beta limit was exceeded at the 3513 and OHF impoundments by either /sup 90/Sr or tritium levels. At the 3513 impoundment, there was substantial evidence that the downgradient groundwater has been contaminated by chromium and lead and possibly by halogenated organic compounds. At the OHF impoundment, the mean level of tritium measured in the upgradient well (about 91,000 Bq/L as compared with 80,000 Bq/L in the downgradient wells) indicated that the groundwater quality has been affected by the radioactive wastes buried in the low-level radioactive waste burial ground solid waste storage area-5 upgradient of the impoundment. Testing for groundwater contamination, disclosed statistically significant contamination at all three sites.

Groundwater monitoring at three Oak Ridge National Laboratory inactive waste impoundments: results after one year

International Nuclear Information System (INIS)

Francis, C.W.; Stansfield, R.G.

1986-10-01

To determine if the migration of potential contaminants from three inactive waste impoundments at Oak Ridge National Laboratory poses a threat to groundwater quality, at least one upgradient groundwater monitoring well and threee downgradient monitoring wells were installed at each impoundment in early 1985. These three unlined impoundments, formerly used to collect and, in some instances, treat wastewater are: the 3513 impoundment; the Old Hydrofracture Facility (OHF) impoundment; and the Homogeneous Reactor Experimnt No. 2 impoundment. Groundwater samples were collected quarterly for one year. Analyses were conducted for the groundwater protection parameters promulgated by the Resource Conservation and Recovery Act. The groundwater samples were also analyzed for polychlorinated biphenyls, copper, nickel, zinc, 90 Sr, 137 Cs, and tritium. The contaminants found most often to affect groundwater quality at all three waste impoundments were radionuclides. For example, mean concentrations of gross beta and gross alpha activity exceeded drinking water limits at all three sites. The gross beta limit was exceeded at the 3513 and OHF impoundments by either 90 Sr or tritium levels. At the 3513 impoundment, there was substantial evidence that the downgradient groundwater has been contaminated by chromium and lead and possibly by halogenated organic compounds. At the OHF impoundment, the mean level of tritium measured in the upgradient well (about 91,000 Bq/L as compared with 80,000 Bq/L in the downgradient wells) indicated that the groundwater quality has been affected by the radioactive wastes buried in the low-level radioactive waste burial ground solid waste storage area-5 upgradient of the impoundment. Testing for groundwater contamination, disclosed statistically significant contamination at all three sites

Groundwater Quality Data in the Mojave Study Unit, 2008: Results from the California GAMA Program

Science.gov (United States)

Mathany, Timothy M.; Belitz, Kenneth

2009-01-01

ground water. In total, over 230 constituents and water-quality indicators (field parameters) were investigated. Three types of quality-control samples (blanks, replicates, and matrix spikes) each were collected at approximately 5-8 percent of the wells, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a significant source of bias in the data for the groundwater samples. Differences between replicate samples generally were within acceptable ranges, indicating acceptable analytical reproducibility. Matrix spike recoveries were within acceptable ranges for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, untreated groundwater typically is treated, disinfected, or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to untreated ground water. However, to provide some context for the results, concentrations of constituents measured in the untreated ground water were compared with regulatory and non-regulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH) and thresholds established for aesthetic and technical concerns by CDPH. Comparisons between data collected for this study and thresholds for drinking-water are for illustrative purposes only, and are not indicative of compliance or non-compliance with those thresholds. Most constituents that were detected in groundwater samples in the 59 wells in MOJO were found at concentrations below drinking-water thresholds. In MOJO's 52 grid wells, volatile organic compounds (VOCs) were detected in 40 percent of the wells, and pesticides and pesticide degradates were detected in 23 percent of the grid wel

Groundwater-quality data in the Klamath Mountains study unit, 2010: results from the California GAMA Program

Science.gov (United States)

Mathany, Timothy M.; Belitz, Kenneth

2014-01-01

radioactivity, and microbial indicators (total coliform and Escherichia coli [E. coli]). Isotopic tracers (stable isotopes of hydrogen and oxygen in water, isotopic ratios of dissolved strontium in water, and stable isotopes of carbon in dissolved inorganic carbon), dissolved noble gases, and age-dating tracers (tritium and carbon-14) were measured to help identify sources and ages of sampled groundwater. Quality-control samples (field blanks, replicate sample pairs, and matrix spikes) were collected at 13 percent of the sites in the KLAM study unit, and the results were used to evaluate the quality of the data from the groundwater samples. Field blank samples rarely contained detectable concentrations of any constituent, indicating that contamination from sample collection or analysis was not a significant source of bias in the data for the groundwater samples. More than 99 percent of the replicate pair samples were within acceptable limits of variability. Matrix-spike sample recoveries were within the acceptable range (70 to 130 percent) for approximately 91 percent of the compounds. This study did not evaluate the quality of water delivered to consumers. After withdrawal, groundwater typically is treated, disinfected, and (or) blended with other waters to maintain water quality. Regulatory benchmarks apply to water that is delivered to the consumer, not to untreated groundwater. However, to provide some context for the results, concentrations of constituents measured in the untreated groundwater were compared with regulatory and non-regulatory health-based benchmarks established by the U.S. Environmental Protection Agency (USEPA) and CDPH, and to non-health-based benchmarks established for aesthetic concerns by the CDPH. Comparisons between data collected for this study and benchmarks for drinking water are for illustrative purposes only and are not indicative of compliance or non-compliance with those benchmarks. All concentrations of organic constituents from grid sites

Core drilling of drillholes ONK-KR13, ONK-KR14 and ONK-KR15 in ONKALO at Olkiluoto 2010 - 2011

International Nuclear Information System (INIS)

Toropainen, V.

2011-08-01

As a part of the confirming site investigations at Olkiluoto, Suomen Malmi Oy (Smoy) core drilled three drillholes ONK-KR13 (120.45 m), ONK-KR14 (75.27 m) and ONK-KR15 (79.96 m) in ONKALO, at Olkiluoto in June 2010 - March 2011. The diameter of the drillholes is 75.7 mm. Sodium fluorescein was used as a label agent in the drilling water, and the drillholes were washed and flushed after the drilling. The deviations of the drillholes were measured with the deviation measuring instruments EMS and Gyro. The core samples were logged according to Posiva's normal procedure for drillholes. The main rock types are veined and diatexitic gneisses and pegmatitic granite. The average natural fracture frequencies and RQDs of the core samples are 1.6 pcs/m and 97.0 % (ONK-KR13), 0.5 pcs/m and 99.3 % (ONK-KR14) and 1.6 pcs/m and 97.3 % (ONK-KR15). In drillhole ONK-KR13 one, and in drillhole ONK-KR15 three fractured zones were intersected. There was no fractured zones in drillhole ONK-KR14. Rock mechanical tests were performed to core samples. The average uniaxial compressive strength was 143.2 MPa, the average Young's Modulus was 57.3 GPa and the average Poisson's ratio was 0.25. (orig.)

Stable isotope signatures of gases liberated from fluid inclusions in bedrock at Olkiluoto

International Nuclear Information System (INIS)

Eichinger, F.; Meier, D.; Haemmerli, J.; Diamond, L.

2010-12-01

Fluid inclusions in quartzes of the Olkiluoto bedrock contain gaseous N 2 , CO 2 , H 2 , CH 4 , and higher hydrocarbons in varying proportions. Stable carbon and hydrogen isotope signatures of the gas phases give valuable information on their origin and the formation conditions. In previous studies, a method to liberate and quantify the gases trapped in fluid inclusions was developed. It allowed determining the carbon isotope signatures of liberated CO 2 , CH 4 and higher hydrocarbons (HHC), but no hydrogen isotope data were acquired. The method was advanced and, in this study, also stable hydrogen isotopes of CH 4 and H 2 liberated from fluid inclusions could be analysed. The stable carbon signatures of methane and higher hydrocarbons, as well as the hydrogen isotope signatures of methane indicate a predominant thermogenic provenance for those gases. (orig.)

Geological data acquisition for site characterisation at Olkiluoto: a framework for the phase of underground investigations

International Nuclear Information System (INIS)

Milnes, A.G.; Aaltonen, I.; Kemppainen, K.; Mattila, J.; Wikstroem, L.; Front, K.; Kaerki, A.; Gehoer, S.; Paulamaeki, S.; Paananen, M.; Ahokas, T.

2007-05-01

'Geological data acquisition' is a general term for the collection of observations and measurements by direct observation of exposed bedrock in the field (i.e. in natural outcrops and trenches, in drillholes, and in tunnels and other underground excavations). Only field-based data acquisition is included in this report: laboratory-based investigations will be continued, based on the field data and sampling, and all the data will be subject to discipline-specific processing, as the project proceeds. The ultimate aim of geological data acquisition is to provide the necessary data base for geological models of the bedrock of the Olkiluoto site, in connection with the construction of an underground rock characterisation facility, ONKALO, and a repository for spent nuclear fuel, at about 500m depth. Geological data acquisition plays a central role in site characterisation and modelling, and is intended to provide a solid platform on which the other disciplines (rock mechanics, hydrogeology, seismic risk assessment, etc.) can base their investigations. Based on consideration of a series of guidelines (e.g. modelling scale, source of data, level of investigation, national and international experience, special conditions at Olkiluoto, need for process understanding), a project-oriented 'framework' has been developed as a background to the different projects within the geological data acquisition programme. Each project will require its own system of data acquisition (methodology, spreadsheets, protocols, etc.), as described in the corresponding reports; the present report concentrates on the general principles which lie behind the different methodologies and data sheets. These principles are treated under three main headings: characterization of intact rock, characterization of deformation zone intersections, and characterization of individual fractures. Geological mapping of natural outcrops and trenches at Olkiluoto, and lithological logging of more than 40 rock cores

Groundwater-quality data in the Santa Barbara study unit, 2011: results from the California GAMA Program

Science.gov (United States)

Davis, Tracy A.; Kulongoski, Justin T.; Belitz, Kenneth

2013-01-01

elements, nutrients, major and minor ions, silica, total dissolved solids [TDS], alkalinity, and arsenic, chromium, and iron species); and radioactive constituents (radon-222 and gross alpha and gross beta radioactivity). Naturally occurring isotopes (stable isotopes of hydrogen and oxygen in water, stables isotopes of inorganic carbon and boron dissolved in water, isotope ratios of dissolved strontium, tritium activities, and carbon-14 abundances) and dissolved noble gases also were measured to help identify the sources and ages of the sampled groundwater. In total, 281 constituents and water-quality indicators were measured. Three types of quality-control samples (blanks, replicates, and matrix spikes) were collected at up to 12 percent of the wells in the Santa Barbara study unit, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Blanks rarely contained detectable concentrations of any constituent, suggesting that contamination from sample collection procedures was not a significant source of bias in the data for the groundwater samples. Replicate samples generally were within the limits of acceptable analytical reproducibility. Matrix-spike recoveries were within the acceptable range (70 to 130 percent) for approximately 82 percent of the compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, untreated groundwater typically is treated, disinfected, and (or) blended with other waters to maintain water quality. Regulatory benchmarks apply to water that is served to the consumer, not to untreated groundwater. However, to provide some context for the results, concentrations of constituents measured in the untreated groundwater were compared with regulatory and non-regulatory health-based benchmarks established by the U.S. Environmental Protection Agency (USEPA) and CDPH and to non-regulatory benchmarks established for aesthetic concerns by

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Surface and near-surface hydrological modelling in the biosphere assessment BSA-2012

International Nuclear Information System (INIS)

Karvonen, T.

2013-05-01

The Finnish nuclear waste disposal company, Posiva Oy, is planning an underground repository for spent nuclear fuel to be constructed on the island of Olkiluoto on the south-west coast of Finland. This study is part of the biosphere assessment (BSA-2012) within the safety case for the repository. The surface hydrological modelling described in this report is aimed at providing link between radionuclide transport in the geosphere and in the biosphere systems. The SVAT-model and Olkiluoto site scale surface hydrological model were calibrated and validated in the present day conditions using the input data provided by the Olkiluoto Monitoring Programme (OMO). During the next 10 000 years the terrain and ecosystem development is to a large extent driven by the postglacial crustal uplift. UNTAMO is a GIS toolbox developed for simulating land-uplift driven or other changes in the biosphere. All the spatial and temporal input data (excluding meteorological data) needed in the surface hydrological modelling were provided by the UNTAMO toolbox. The specific outputs given by UNTAMO toolbox are time-dependent evolution of the biosphere objects. They are continuous and sufficiently homogeneous sub-areas of the modelled area that could potentially receive radionuclides released from the repository. Possible ecosystem types for biosphere objects are coast, lake, river, forest, cropland, pasture and wetland. The primary goal of this study was to compute vertical and horizontal water fluxes in the biosphere objects. These data will be used in the biosphere radionuclide transport calculations. The method adopted here is based on calculating average vertical and horizontal fluxes for biosphere objects from the results of the full 3D-model. It was not necessary to develop any simplified hydrological model for the biosphere objects. This report includes modelling results from for the Reference Case (present day climate) and Terr M axAgri Case (maximum extent of agricultural areas and

Land uplift in the Olkiluoto-Pyhaejaervi area, southwestern Finland, during the last 8000 years

International Nuclear Information System (INIS)

Eronen, M.; Glueckert, G.; Rantala, P.; Plassche, O. van de; Plicht, J. van der

1995-12-01

Land is rising in relation to sea level several millimetres per year on the coast of southwestern Finland. The aim of the study was to gather information about the land uplift process. Sediment samples were collected from 14 lakes lying at different altitudes in the area between Olkiluoto and Lake Pyhaejaervi in southwestern Finland to study the relative sea-level changes and land uplift. The present-day lakes had once been below the waters of the Baltic, but due to uplift they had been isolated from the sea one after another. The isolation points in the sediments were determined by preliminary diatom analyses. They show the change from brackish to fresh-water conditions, and these horizons were then dated by two radiocarbon assays. (37 refs., 18 figs., 1 tab.)

Groundwater-surface water interaction

International Nuclear Information System (INIS)

White, P.A.; Clausen, B.; Hunt, B.; Cameron, S.; Weir, J.J.

2001-01-01

This chapter discusses natural and modified interactions between groundwater and surface water. Theory on recharge to groundwater from rivers is introduced, and the relative importance of groundwater recharge from rivers is illustrated with an example from the Ngaruroro River, Hawke's Bay. Some of the techniques used to identify and measure recharge to groundwater from gravel-bed rivers will be outlined, with examples from the Ngaruroro River, where the recharge reach is relatively well defined, and from the Rakaia River, where it is poorly defined. Groundwater recharged from rivers can have characteristic chemical and isotopic signatures, as shown by Waimakariri River water in the Christchurch-West Melton groundwater system. The incorporation of groundwater-river interaction in a regional groundwater flow model is outlined for the Waimea Plains, and relationships between river scour and groundwater recharge are examined for the Waimakariri River. Springs are the result of natural discharge from groundwater systems and are important water sources. The interactions between groundwater systems, springs, and river flow for the Avon River in New Zealand will be outlined. The theory of depletion of stream flow by groundwater pumpage will be introduced with a case study from Canterbury, and salt-water intrusion into groundwater systems with examples from Nelson and Christchurch. The theory of artificial recharge to groundwater systems is introduced with a case study from Hawke's Bay. Wetlands are important to flora, and the relationship of the wetland environment to groundwater hydrology will be discussed, with an example from the South Taupo wetland. (author). 56 refs., 25 figs., 3 tabs

Hanford groundwater scenario studies

International Nuclear Information System (INIS)

Arnett, R.C.; Gephart, R.E.; Deju, R.A.; Cole, C.R.; Ahlstrom, S.W.

1977-05-01

This report documents the results of two Hanford groundwater scenario studies. The first study examines the hydrologic impact of increased groundwater recharge resulting from agricultural development in the Cold Creek Valley located west of the Hanford Reservation. The second study involves recovering liquid radioactive waste which has leaked into the groundwater flow system from a hypothetical buried tank containing high-level radioactive waste. The predictive and control capacity of the onsite Hanford modeling technology is used to evaluate both scenarios. The results of the first study indicate that Cold Creek Valley irrigationis unlikely to cause significant changes in the water table underlying the high-level waste areas or in the movement of radionuclides already in the groundwater. The hypothetical tank leak study showed that an active response (in this case waste recovery) can be modeled and is a possible alternative to passive monitoring of radionuclide movement in the unlikely event that high-level waste is introduced into the groundwater

Groundwater sustainability and groundwater/surface-water interaction in arid Dunhuang Basin, northwest China

Science.gov (United States)

Lin, Jingjing; Ma, Rui; Hu, Yalu; Sun, Ziyong; Wang, Yanxin; McCarter, Colin P. R.

2018-03-01

The Dunhuang Basin, a typical inland basin in northwestern China, suffers a net loss of groundwater and the occasional disappearance of the Crescent Lake. Within this region, the groundwater/surface-water interactions are important for the sustainability of the groundwater resources. A three-dimensional transient groundwater flow model was established and calibrated using MODFLOW 2000, which was used to predict changes to these interactions once a water diversion project is completed. The simulated results indicate that introducing water from outside of the basin into the Shule and Danghe rivers could reverse the negative groundwater balance in the Basin. River-water/groundwater interactions control the groundwater hydrology, where river leakage to the groundwater in the Basin will increase from 3,114 × 104 m3/year in 2017 to 11,875 × 104 m3/year in 2021, and to 17,039 × 104 m3/year in 2036. In comparison, groundwater discharge to the rivers will decrease from 3277 × 104 m3/year in 2017 to 1857 × 104 m3/year in 2021, and to 510 × 104 m3/year by 2036; thus, the hydrology will switch from groundwater discharge to groundwater recharge after implementing the water diversion project. The simulation indicates that the increased net river infiltration due to the water diversion project will raise the water table and then effectively increasing the water level of the Crescent Lake, as the lake level is contiguous with the water table. However, the regional phreatic evaporation will be enhanced, which may intensify soil salinization in the Dunhuang Basin. These results can guide the water allocation scheme for the water diversion project to alleviate groundwater depletion and mitigate geo-environmental problem.

Groundwater-Quality Data in the South Coast Interior Basins Study Unit, 2008: Results from the California GAMA Program

Science.gov (United States)

Mathany, Timothy M.; Kulongoski, Justin T.; Ray, Mary C.; Belitz, Kenneth

2009-01-01

], and radioactive constituents [gross alpha and gross beta radioactivity and radon-222]. Naturally occurring isotopes [stable isotopes of hydrogen, oxygen, and carbon, and activities of tritium and carbon-14] and dissolved noble gases also were measured to help identify the sources and ages of the sampled groundwater. In total, 288 constituents and water-quality indicators (field parameters) were investigated. Three types of quality-control samples (blanks, replicates, and matrix spikes) each were collected at approximately 4-11 percent of the wells, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a significant source of bias in the data obtained from the groundwater samples. Differences between replicate samples generally were less than 10 percent relative standard deviation, indicating acceptable analytical reproducibility. Matrix spike recoveries were within the acceptable range (70 to 130 percent) for most compounds. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, untreated groundwater typically is treated, disinfected, and/or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to untreated groundwater. However, to provide some context for the results, concentrations of constituents measured in the untreated groundwater were compared with regulatory and nonregulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH), and to nonregulatory thresholds established for aesthetic and technical concerns by CDPH. Comparisons between data collected for this study and thresholds for drinking water are for illustrative purposes only, and are not indicative of complia

Game statistics for the Island of Olkiluoto in 2011-2012

Energy Technology Data Exchange (ETDEWEB)

Niemi, M.; Nieminen, M. [Faunatica Oy, Espoo (Finland); Jussila, I. [Turku Univ. (Finland)

2012-11-15

The game statistics for the island of Olkiluoto were updated in the summer 2012 and compared with earlier statistics. Population size estimates are based on interviews of the local hunters. No moose or deer inventories were made in the winter 2011-2012. The moose population has been decreasing slightly during the past ten years. The increasing lynx population has decreasing effect on small ungulate (white-tailed deer and roe deer) populations. The number of hunted mountain hares and European brown hares decreased when comparing the previous year. In addition, the number of hunted raccoon dogs was about 50 per cent lower than in the year 2010. Altogether 27 waterfowls were hunted in 2011. The population of mountain hare is abundant, despite that there were lynx living on the eastern part of island during the winter 2011. Based on track observations, there are pine martens living on the area as well. In addition, there were some observations of wolves visiting on the area. The winter 2011-2012 was milder than the previous one, and it seemed that young swans wintering on the area survived better that in the previous winter. (orig.)

Enhancing the economic competitiveness of the Olkiluoto Nuclear Power Plants

International Nuclear Information System (INIS)

Paavola, M.

1996-01-01

The two 710 MWe BWRs at Olkiluoto in Finland have been running for the past ten years with a capacity factor of over 90%. The success of these reactors in being competitive with various forms of fossil fuel power production is attributed to a number of key factors. Of these, the most important is that the staff of the utility and contractors and suppliers personnel are well trained, committed and able to learn new things. Strict safety regulations contribute to competitiveness because the good practice required and the need to keep the plant in mint condition lead to fewer production interruptions and to lower operational costs in the long run. Continuous investment in updating the plant is necessary to maintain high productivity throughout its lifetime. A long-term operational plan coupled with carefully prepared maintenance outages and high quality workmanship also helps to ensure good performance. Better fuel designs and high quality have enabled the plant output to be increased while stabilising or reducing fuel costs. Money for waste management has been reserved since the start of plant operation so that economic production can be ensured during the latter part of the plant lifetime. (UK)

Game statistics for the Island of Olkiluoto in 2011-2012

International Nuclear Information System (INIS)

Niemi, M.; Nieminen, M.; Jussila, I.

2012-11-01

The game statistics for the island of Olkiluoto were updated in the summer 2012 and compared with earlier statistics. Population size estimates are based on interviews of the local hunters. No moose or deer inventories were made in the winter 2011-2012. The moose population has been decreasing slightly during the past ten years. The increasing lynx population has decreasing effect on small ungulate (white-tailed deer and roe deer) populations. The number of hunted mountain hares and European brown hares decreased when comparing the previous year. In addition, the number of hunted raccoon dogs was about 50 per cent lower than in the year 2010. Altogether 27 waterfowls were hunted in 2011. The population of mountain hare is abundant, despite that there were lynx living on the eastern part of island during the winter 2011. Based on track observations, there are pine martens living on the area as well. In addition, there were some observations of wolves visiting on the area. The winter 2011-2012 was milder than the previous one, and it seemed that young swans wintering on the area survived better that in the previous winter. (orig.)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Features, events and processes 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

Features, Events and Processes sits within Posiva Oy's Safety Case 'TURVA-2012' portfolio and has the objective of presenting the main features, events and processes (FEPs) that are considered to be potentially significant for the long-term safety of the planned KBS-3V repository for spent nuclear fuel at Olkiluoto. The primary purpose of this report is to support Performance Assessment, Formulation of Radionuclide Release Scenarios, Assessment of the Radionuclide Release Scenarios for the Repository System and Biosphere Assessment by ensuring that the scenarios are comprehensive and take account of all significant FEPs. The main FEPs potentially affecting the disposal system are described for each relevant subsystem component or barrier (i.e. the spent nuclear fuel, the canister, the buffer and tunnel backfill, the auxiliary components, the geosphere and the surface environment). In addition, a small number of external FEPs that may potentially influence the evolution of the disposal system are described. The conceptual understanding and operation of each FEP is described, together with the main features (variables) of the disposal system that may affect its occurrence or significance. Olkiluoto-specific issues are considered when relevant. The main uncertainties (conceptual and parameter/data) associated with each FEP that may affect understanding are also documented. Indicative parameter values are provided, in some cases, to illustrate the magnitude or rate of a process, but it is not the intention of this report to provide the complete set of numerical values that are used in the quantitative safety assessment calculations. Many of the FEPs are interdependent and, therefore, the descriptions also identify the most important direct couplings between the FEPs. This information is used in the formulation of scenarios to ensure the conceptual models and calculational cases are both comprehensive and representative. (orig.)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Features, events and processes 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

Features, Events and Processes sits within Posiva Oy's Safety Case 'TURVA-2012' portfolio and has the objective of presenting the main features, events and processes (FEPs) that are considered to be potentially significant for the long-term safety of the planned KBS-3V repository for spent nuclear fuel at Olkiluoto. The primary purpose of this report is to support Performance Assessment, Formulation of Radionuclide Release Scenarios, Assessment of the Radionuclide Release Scenarios for the Repository System and Biosphere Assessment by ensuring that the scenarios are comprehensive and take account of all significant FEPs. The main FEPs potentially affecting the disposal system are described for each relevant subsystem component or barrier (i.e. the spent nuclear fuel, the canister, the buffer and tunnel backfill, the auxiliary components, the geosphere and the surface environment). In addition, a small number of external FEPs that may potentially influence the evolution of the disposal system are described. The conceptual understanding and operation of each FEP is described, together with the main features (variables) of the disposal system that may affect its occurrence or significance. Olkiluoto-specific issues are considered when relevant. The main uncertainties (conceptual and parameter/data) associated with each FEP that may affect understanding are also documented. Indicative parameter values are provided, in some cases, to illustrate the magnitude or rate of a process, but it is not the intention of this report to provide the complete set of numerical values that are used in the quantitative safety assessment calculations. Many of the FEPs are interdependent and, therefore, the descriptions also identify the most important direct couplings between the FEPs. This information is used in the formulation of scenarios to ensure the conceptual models and calculational cases are both comprehensive and representative. (orig.)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Features, events and processes 2012

International Nuclear Information System (INIS)

2012-12-01

Features, Events and Processes sits within Posiva Oy's Safety Case 'TURVA-2012' portfolio and has the objective of presenting the main features, events and processes (FEPs) that are considered to be potentially significant for the long-term safety of the planned KBS-3V repository for spent nuclear fuel at Olkiluoto. The primary purpose of this report is to support Performance Assessment, Formulation of Radionuclide Release Scenarios, Assessment of the Radionuclide Release Scenarios for the Repository System and Biosphere Assessment by ensuring that the scenarios are comprehensive and take account of all significant FEPs. The main FEPs potentially affecting the disposal system are described for each relevant subsystem component or barrier (i.e. the spent nuclear fuel, the canister, the buffer and tunnel backfill, the auxiliary components, the geosphere and the surface environment). In addition, a small number of external FEPs that may potentially influence the evolution of the disposal system are described. The conceptual understanding and operation of each FEP is described, together with the main features (variables) of the disposal system that may affect its occurrence or significance. Olkiluoto-specific issues are considered when relevant. The main uncertainties (conceptual and parameter/data) associated with each FEP that may affect understanding are also documented. Indicative parameter values are provided, in some cases, to illustrate the magnitude or rate of a process, but it is not the intention of this report to provide the complete set of numerical values that are used in the quantitative safety assessment calculations. Many of the FEPs are interdependent and, therefore, the descriptions also identify the most important direct couplings between the FEPs. This information is used in the formulation of scenarios to ensure the conceptual models and calculational cases are both comprehensive and representative. (orig.)

Electromagnetic SAMPO monitoring soundings at OLKILUOTO in 2012 with updated interpretations

International Nuclear Information System (INIS)

Korhonen, K.

2013-11-01

The Geological Survey of Finland (GTK) has carried out electromagnetic depth soundings annually at fixed stations at Olkiluoto since 2004 as part of a monitoring programme. The goal of the programme is to detect and monitor changes in the electrical properties of the bedrock above and in the vicinity of the ONKALO tunnel which will serve as a part of the future underground nuclear waste disposal facility. A new Sampo monitoring survey was carried out during October 2012. The survey plan of 2011 was slightly modified and 36 soundings at 16 measurement stations were carried out. The nominal coil separations of 200, 400, 500, 600 and 800 meters were used. Interpretations at eight selected stations were updated with the new data. The interpretations indicate consistent statistically significant changes. Annual increases in resistivity were detected at stations to the East of ONKALO while annual decreases in resistivity were detected to the West of ONKALO. However, these changes need to be considered keeping in mind the high degree of uncertainty associated with the data and their interpretations. (orig.)

Elecromagnetic Sampo monitoring soundings at Olkiluoto in 2013 with updated interpretations

International Nuclear Information System (INIS)

Korhonen, K.

2014-10-01

The Geological Survey of Finland (GTK) has carried out electromagnetic depth soundings annually at fixed stations in Olkiluoto since 2004 as part of a monitoring program. The goal of the monitoring program is to detect and monitor changes in the electrical properties of the bedrock in the vicinity of the ONKALO underground research facility which will constitute a part of the final nuclear waste repository. A new Sampo monitoring survey was carried out by GTK in October 2013. The survey consists of 37 soundings performed at 17 measurement stations. The nominal coil separations of 200, 400, 500, 600 and 800 metres were used depending on the station. Layer-model interpretations of soundings at eight selected stations were updated with the new data. The interpretations indicate consistent annual changes. Resistivities be-low stations to the East of the ONKALO facility appear to increase annually. In contrast, resistivities below stations to the West of the ONKALO facility appear to decrease annually. However, these changes need to be considered keeping in mind the uncertainties associated with the data and their interpretations. (orig.)

Fracture-specific pressure measurements at the Olkiluoto site in Eurajoki drillhole OL-KR39

International Nuclear Information System (INIS)

Ripatti, K.; Poellaenen, J.; Hurmerinta, E.; Rouhiainen, P.

2011-12-01

An option was built to the Posiva Flow Log, Difference flow method (PFL DIFF). A double packer device was combined together with a PFL DIFF probe. The new tool was needed for measurements of the very low hydraulic head. Indications of these were detected earlier in some fractures of drillhole OL-KR39. The target fractures could be measured with the accurate absolute pressure sensor in the PFL DIFF probe. Principles of the methods and the results of measurements are presented in this report. The measurements were carried out in drillhole OL-KR39 at the Olkiluoto investigation site between April 2011 and May 2011. The device used includes a sensor for single point resistance (SPR). SPR measurement is used to place the device accurately on the chosen fracture. The section length limited by the packers is about 1 m. The measurements were carried out in natural (i.e. un-pumped) conditions. The same measuring program was employed in all chosen fractures. Electrical conductivity (EC) of drillhole water and flow rate along the drillhole were also measured in conjunction with the pressure measurements. (orig.)

Dynamics of Agricultural Groundwater Extraction

NARCIS (Netherlands)

Hellegers, P.J.G.J.; Zilberman, D.; Ierland, van E.C.

2001-01-01

Agricultural shallow groundwater extraction can result in desiccation of neighbouring nature reserves and degradation of groundwater quality in the Netherlands, whereas both externalities are often not considered when agricultural groundwater extraction patterns are being determined. A model is

Groundwater-Quality Data in the South Coast Range-Coastal Study Unit, 2008: Results from the California GAMA Program

Science.gov (United States)

Mathany, Timothy M.; Burton, Carmen A.; Land, Michael; Belitz, Kenneth

2010-01-01

the 70 wells sampled, 3 surface-water samples were collected in streams near 2 of the sampled wells in order to better comprehend the interaction between groundwater and surface water in the area. The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOC], pesticides and pesticide degradates, polar pesticides and metabolites, and pharmaceutical compounds), constituents of special interest (perchlorate, N-nitrosodimethylamine [NDMA], and 1,2,3-TCP), naturally occurring inorganic constituents (trace elements, nutrients, dissolved organic carbon [DOC], major and minor ions, silica, total dissolved solids [TDS], and alkalinity), and radioactive constituents (gross alpha and gross beta radioactivity). Naturally occurring isotopes (stable isotopes of hydrogen and oxygen in water, stable isotopes of nitrogen and oxygen in dissolved nitrate, stable isotopes of sulfur in dissolved sulfate, stable isotopes of carbon in dissolved inorganic carbon, activities of tritium, and carbon-14 abundance), and dissolved gases (including noble gases) also were measured to help identify the sources and ages of the sampled groundwater. In total, 298 constituents and field water-quality indicators were investigated. Three types of quality-control samples (blanks, replicates, and matrix-spikes) were collected at approximately 3 to 12 percent of the wells in the SCRC study unit, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination from sample collection procedures was not a significant source of bias in the data for the groundwater samples. Differences between replicate samples generally were less than 10 percent relative and/or standard deviation, indicating acceptable analytical reproducibility. Matrix-spike recoveries were within the acceptable range (70 to 130 percent) for approximately 84

Ground-Water Quality Data in the Coachella Valley Study Unit, 2007: Results from the California GAMA Program

Science.gov (United States)

Goldrath, Dara A.; Wright, Michael T.; Belitz, Kenneth

2009-01-01

ground water. A quality-control sample (blank, replicate, or matrix spike) was collected at approximately one quarter of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Assessment of the quality-control information resulted in V-coding less than 0.1 percent of the data collected. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain acceptable water quality. Regulatory thresholds apply to treated water that is supplied to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and the California Department of Public Health (CDPH) and thresholds established for aesthetic purposes (secondary maximum contaminant levels, SMCL-CA) by CDPH. Most constituents detected in ground-water samples were at concentrations below drinking-water thresholds. Volatile organic compounds, pesticides, and pesticide degradates were detected in less than one-third of the grid well samples collected. All VOC and pesticide concentrations measured were below health-based thresholds. Potential waste-water indicators were detected in less than half of the wells sampled, and no detections were above health-based thresholds. Perchlorate was detected in seven grid wells; concentrations from two wells were above the CDPH maximum contaminant level (MCL-CA). Most detections of trace elements in samples collected from COA Study Unit wells were below water-quality thresholds. Exceptions include five samples of arsenic that were above the USEPA maximum contaminant level (MCL-US), two detections of boron above the CDPH notification level (NL-CA), and two detections of mol

Diffusion in the matrix of rocks from Olkiluoto. The effect of anion exclusion

International Nuclear Information System (INIS)

Valkiainen, M.; Aalto, H.; Olin, M.; Lindberg, A.; Siitari-Kauppi, M.

1995-12-01

Diffusion in the rock matrix is dependent on two basic factors: the effective diffusion conductivity of the rock and the rock-capacity factor. The aim of this ongoing research is to study both of these factors more closely by finding evidence and studying the significance of anion exclusion and surface diffusion. The material for the study was selected form the drill-core of the drill-hole OL-KR5 from Olkiluoto investigations site. Six rock-types were included in the study, three unaltered and three altered. The water-types selected can be divided to two groups: in one the ionic strength is varied, in the another the ionic type is varied. The diffusion measurements were carried out partly by the equilibration-leaching method, partly by the through-diffusion method. The measurements by the equilibration-leaching method were performed in the anaerobic cabinet and the through-diffusion measurement in laboratory room conditions. Radioactive isotopes 3 H, 35 S, 36 Cl and 22 Na were selected as tracers. This report contains results of the equilibration-leaching measurements and through- diffusion measurements using 3 H (HTO), 36 Cl (Cl-) and 35 S(SO 4 2- ) as tracers. The rock-types under study were also studied in the University of Helsinki, Department of Chemistry using polymethylmethacrylate labelled with 14 C revealing the pore structure. Also, results of specific surface area measurements made in BAM, Berlin are given. The comparison of results obtained by the gas diffusion method at the University of Jyvaeskylae to the results obtained by tritium are also appended. (12 refs., 20 figs., 10 tabs.)

Seafloor mapping at Olkiluoto western coast of Finland

International Nuclear Information System (INIS)

Ilmarinen, K.; Leinikki, J.; Oulasvirta, P.

2009-02-01

The objective of the study was to investigate the seafloor of shallow areas around Olkiluoto island, western Finland. The surveys were carried out by Alleco Ltd. Posiva will use the data for modeling purposes. The investigations included bathymetric surveys, sediment sampling and assessment of benthic macrophytes and macrozoobenthos in the underwater parts of six pre-defined survey transects extending from land to the sea. Sediment sampling and the assessment of benthic organisms were done by SCUBA diving. The study area showed a great variation in environmental conditions. Olkiluoto stands between almost open sea and extremely sheltered river mouth area of Lapinjoki. Two of the transects were more than 7 meters deep and included both hard and soft sand bottom. Whereas rest of the transects were shallow with mostly soft clay, mud and silt bottom. Altogether 27 species of algae including five species of stoneworts (Charophyta), one species of water moss (Bryophyta) and 16 species of vascular plants (Tracheophyta) were found. The most abundant group was vascular plants, between the other groups of macroalgae big differences in the abundance were not seen. Furthermore altogether 43 species of macrozoobenthos (Invertebrata) were found, of which six species were sessile bottom fauna (permanently attached fauna). The most abundant groups in the bottom samples were bivalves (Lamellibranchiata) (996 individuals per m 2 ), snails (Gastropoda) (739 individuals per m 2 ) and polychaetes (Polychaeta) (542 individuals per m 2 ). The total abundance of macrozoobenthos on all transects was 2 899 individuals per m 2 . The biggest groups by biomass were bivalves (fresh weight 87 054 mg per m 2 ) and polychaetes (fresh weight 12 983 mg per m 2 ). Transect 1 was the richest in number of species of the deep and exposed transects 1 and 2. The transect 5 had the highest diversity of all the shallow soft bottom transects 3, 4, 5 and 5a. The high diversity of the transect 1 and 5 may be

Seafloor mapping at Olkiluoto western coast of Finland

Energy Technology Data Exchange (ETDEWEB)

Ilmarinen, K.; Leinikki, J.; Oulasvirta, P. (Alleco Oy, Helsinki (Finland))

2009-02-15

The objective of the study was to investigate the seafloor of shallow areas around Olkiluoto island, western Finland. The surveys were carried out by Alleco Ltd. Posiva will use the data for modeling purposes. The investigations included bathymetric surveys, sediment sampling and assessment of benthic macrophytes and macrozoobenthos in the underwater parts of six pre-defined survey transects extending from land to the sea. Sediment sampling and the assessment of benthic organisms were done by SCUBA diving. The study area showed a great variation in environmental conditions. Olkiluoto stands between almost open sea and extremely sheltered river mouth area of Lapinjoki. Two of the transects were more than 7 meters deep and included both hard and soft sand bottom. Whereas rest of the transects were shallow with mostly soft clay, mud and silt bottom. Altogether 27 species of algae including five species of stoneworts (Charophyta), one species of water moss (Bryophyta) and 16 species of vascular plants (Tracheophyta) were found. The most abundant group was vascular plants, between the other groups of macroalgae big differences in the abundance were not seen. Furthermore altogether 43 species of macrozoobenthos (Invertebrata) were found, of which six species were sessile bottom fauna (permanently attached fauna). The most abundant groups in the bottom samples were bivalves (Lamellibranchiata) (996 individuals per m2), snails (Gastropoda) (739 individuals per m2) and polychaetes (Polychaeta) (542 individuals per m2). The total abundance of macrozoobenthos on all transects was 2 899 individuals per m2. The biggest groups by biomass were bivalves (fresh weight 87 054 mg per m2) and polychaetes (fresh weight 12 983 mg per m2). Transect 1 was the richest in number of species of the deep and exposed transects 1 and 2. The transect 5 had the highest diversity of all the shallow soft bottom transects 3, 4, 5 and 5a. The high diversity of the transect 1 and 5 may be explained by

Ground-Water Quality Data in the Central Sierra Study Unit, 2006 - Results from the California GAMA Program

Science.gov (United States)

Ferrari, Matthew J.; Fram, Miranda S.; Belitz, Kenneth

2008-01-01

the results for these samples were used to evaluate the quality of the data for the ground-water samples. Results from field blanks indicated contamination was not a noticeable source of bias in the data for ground-water samples. Differences between replicate samples were within acceptable ranges, indicating acceptably low variability. Matrix spike recoveries were within acceptable ranges for most constituents. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, or blended with other waters to maintain water quality. Regulatory thresholds apply to water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH), and thresholds established for aesthetic concerns (Secondary Maximum Contaminant Levels, SMCL-CA) by CDPH. Therefore, any comparisons of the results of this study to drinking-water standards only is for illustrative purposes and is not indicative of compliance or non-compliance to those standards. Most constituents that were detected in ground-water samples were found at concentrations below drinking-water standards or thresholds. Six constituents? fluoride, arsenic, molybdenum, uranium, gross-alpha radioactivity, and radon-222?were detected at concentrations higher than thresholds set for health-based regulatory purposes. Three additional constituents?pH, iron and manganese?were detected at concentrations above thresholds set for aesthetic concerns. Volatile organic compounds (VOCs) and pesticides, were detected in less than one-third of the samples and generally at less than one one-hundredth of a health-based threshold.

Seismic signal in Olkiluoto. Preliminary comparison of underground and surface recordings

International Nuclear Information System (INIS)

Saari, J.; Malm, M.

2015-02-01

Seismic hazard studies in Finland relate to nuclear power plant sites on the Earth's surface. The impact of seismic waves is different on structures on the surface than underground. The purpose of this study is to approximate how ground motions recorded in the ONKALO compare with those on the surface above the ONKALO. Broadband seismometers were installed on the surface and at the depth of 400 m inside the ONKALO in November 2013. The operation time of the seismometers was about nine months. The analysed signals included background noise, teleseismic earthquakes, regional earthquake, local explosions and explosions from the ONKALO site. The studies in Olkiluoto demonstrated that, in general, there is a de-amplification of ground motions in the ONKALO relative to those on the surface, or there is no significant difference between the recordings. The result is likely associated with the type of the seismic source and the relatively shallow depth (400 m) of the underground station. Observed relative amplification related only to nearfield events: the recorded velocity amplitudes on the surface were 2 - 10 times larger than underground. One opposite relation was found in the study: the vertical component of the velocity amplitude of a regional earthquake seems to be about three times larger in ONKALO than on the surface between frequencies 50 Hz and 80 Hz. Definite conclusions concerning amplification or de-amplification cannot be based on the result of this study. In practice, any set of recordings cannot give a comprehensive description of the possible variations, like how the wavefield reflected from the surface interacts with the wavefield coming towards the surface. Numerical modeling is suggested for further studies of this subject. (orig.)

Groundwater quality deterioration as a result of anthropogenic organic air pollution

International Nuclear Information System (INIS)

Renner, I.; Schleyer, R.; Muehlhausen, D.

1990-01-01

For monitoring the atmospherical depositions of organic materials in soil and in particular groundwater, we measured in rain water, soil seepage water and groundwater from four measuring stations in hessian forest areas the AOX sum parameter (organic halogen compounds which can be adsorbed) and numerous single compounds, above all chlorinated hydrocarbons. Anthropogenic organic pollutants are found in all precipitations. Their concentrations are clearly increased as compared to the open land. Of special importance are the atmospherical reaction products of the primary emissions, for example trichloroacetic acid. In analogy to inorganic pollutants, organic pollutant depositions affect above all poorly protected water-bearing strata with thin topsoil layers with a low capacity for adsorption and buffering. Harmful concentrations may be reached here in some cases. (orig.) [de

Continuous measurement of Radon emanations from soil and groundwaters in southern France (Alpes Maritimes). Preliminary results

International Nuclear Information System (INIS)

Oddou, A.; Nault, L.; Campredon, R.; Bernat, M.

1983-01-01

Two types of automated instruments which monitor the emission of radon from rocks and groundwaters are actually being set up in a few localities of the French-Italian Alpe-Maritimes (SE France). The first results are presented [fr

Modelling of hydro-zones for layout planning and numerical flow model in 2006

International Nuclear Information System (INIS)

Ahokas, H.; Vaittinen, T.; Tammisto, E.; Nummela, J.

2007-11-01

As part of the programme for the final disposal of spent nuclear fuel, a model was compiled of hydrogeologically significant zones on the Olkiluoto site. These deterministic zones dominate the groundwater flow especially deep in the bedrock, and because of their nature intersections by disposal tunnels will be avoided, if possible. For layout planning purposes, a brief description was made of the deformation zones of the geological model that intersect the planned repository area and are of hydraulic significance from the point of view of long-term safety. In addition, the hydraulic properties of the zones and the bedrock outside the zones needed for the numerical flow simulations were described. Modelling was mainly based on hydrological observations including an extensive number of single-hole hydraulic tests as well as some long-term pumping test results. Some geophysical mise-a-la-masse results were also used in the compilation of the zones. A comparison between the modelled hydrogeological zones and the deformation zones identified in the geological model of the Olkiluoto site is also presented. (orig.)

Why is the Groundwater Level Rising? A Case Study Using HARTT to Simulate Groundwater Level Dynamic.

Science.gov (United States)

Yihdego, Yohannes; Danis, Cara; Paffard, Andrew

2017-12-01

  Groundwater from a shallow unconfined aquifer at a site in coastal New South Wales has been causing recent water logging issues. A trend of rising groundwater level has been anecdotally observed over the last 10 years. It was not clear whether the changes in groundwater levels were solely natural variations within the groundwater system or whether human interference was driving the level up. Time series topographic images revealed significant surrounding land use changes and human modification to the environment of the groundwater catchment. A statistical model utilising HARTT (multiple linear regression hydrograph analysis method) simulated the groundwater level dynamics at five key monitoring locations and successfully showed a trend of rising groundwater level. Utilising hydrogeological input from field investigations, the model successfully simulated the rise in the water table over time to the present day levels, whilst taking into consideration rainfall and land changes. The underlying geological/land conditions were found to be just as significant as the impact of climate variation. The correlation coefficient for the monitoring bores (MB), excluding MB4, show that the groundwater level fluctuation can be explained by the climate variable (rainfall) with the lag time between the atypical rainfall and groundwater level ranging from 4 to 7 months. The low R2 value for MB4 indicates that there are factors missing in the model which are primarily related to human interference. The elevated groundwater levels in the affected area are the result of long term cumulative land use changes, instigated by humans, which have directly resulted in detrimental changes to the groundwater aquifer properties.

Modeling Effects of Groundwater Basin Closure, and Reversal of Closure, on Groundwater Quality

Science.gov (United States)

Pauloo, R.; Guo, Z.; Fogg, G. E.

2017-12-01

Population growth, the expansion of agriculture, and climate uncertainties have accelerated groundwater pumping and overdraft in aquifers worldwide. In many agricultural basins, a water budget may be stable or not in overdraft, yet disconnected ground and surface water bodies can contribute to the formation of a "closed" basin, where water principally exits the basin as evapotranspiration. Although decreasing water quality associated with increases in Total Dissolved Solids (TDS) have been documented in aquifers across the United States in the past half century, connections between water quality declines and significant changes in hydrologic budgets leading to closed basin formation remain poorly understood. Preliminary results from an analysis with a regional-scale mixing model of the Tulare Lake Basin in California indicate that groundwater salinization resulting from open to closed basin conversion can operate on a decades-to-century long time scale. The only way to reverse groundwater salinization caused by basin closure is to refill the basin and change the hydrologic budget sufficiently for natural groundwater discharge to resume. 3D flow and transport modeling, including the effects of heterogeneity based on a hydrostratigraphic facies model, is used to explore rates and time scales of groundwater salinization and its reversal under different water and land management scenarios. The modeling is also used to ascertain the extent to which local and regional heterogeneity need to be included in order to appropriately upscale the advection-dispersion equation in a basin scale groundwater quality management model. Results imply that persistent managed aquifer recharge may slow groundwater salinization, and complete reversal may be possible at sufficiently high water tables.

Assessing regional groundwater stress for nations using multiple data sources with the groundwater footprint

International Nuclear Information System (INIS)

Gleeson, Tom; Wada, Yoshihide

2013-01-01

Groundwater is a critical resource for agricultural production, ecosystems, drinking water and industry, yet groundwater depletion is accelerating, especially in a number of agriculturally important regions. Assessing the stress of groundwater resources is crucial for science-based policy and management, yet water stress assessments have often neglected groundwater and used single data sources, which may underestimate the uncertainty of the assessment. We consistently analyze and interpret groundwater stress across whole nations using multiple data sources for the first time. We focus on two nations with the highest national groundwater abstraction rates in the world, the United States and India, and use the recently developed groundwater footprint and multiple datasets of groundwater recharge and withdrawal derived from hydrologic models and data synthesis. A minority of aquifers, mostly with known groundwater depletion, show groundwater stress regardless of the input dataset. The majority of aquifers are not stressed with any input data while less than a third are stressed for some input data. In both countries groundwater stress affects agriculturally important regions. In the United States, groundwater stress impacts a lower proportion of the national area and population, and is focused in regions with lower population and water well density compared to India. Importantly, the results indicate that the uncertainty is generally greater between datasets than within datasets and that much of the uncertainty is due to recharge estimates. Assessment of groundwater stress consistently across a nation and assessment of uncertainty using multiple datasets are critical for the development of a science-based rationale for policy and management, especially with regard to where and to what extent to focus limited research and management resources. (letter)

Ground-Water Quality Data in the Southern Sierra Study Unit, 2006 - Results from the California GAMA Program

Science.gov (United States)

Fram, Miranda S.; Belitz, Kenneth

2007-01-01

Ground-water quality in the approximately 1,800 square-mile Southern Sierra study unit (SOSA) was investigated in June 2006 as part of the Statewide Basin Assessment Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment Project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The Southern Sierra study was designed to provide a spatially unbiased assessment of raw ground-water quality within SOSA, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from fifty wells in Kern and Tulare Counties. Thirty-five of the wells were selected using a randomized grid-based method to provide statistical representation of the study area, and fifteen were selected to evaluate changes in water chemistry along ground-water flow paths. The ground-water samples were analyzed for a large number of synthetic organic constituents [volatile organic compounds (VOCs), pesticides and pesticide degradates, pharmaceutical compounds, and wastewater-indicator compounds], constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), and 1,2,3-trichloropropane (1,2,3-TCP)], naturally occurring inorganic constituents [nutrients, major and minor ions, and trace elements], radioactive constituents, and microbial indicators. Naturally occurring isotopes [tritium, and carbon-14, and stable isotopes of hydrogen and oxygen in water], and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, and samples for matrix spikes) were collected for approximately one-eighth of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Assessment of the

Evaluation of groundwater monitoring results at the Hanford Site 200 Area Treated Effluent Disposal Facility

International Nuclear Information System (INIS)

Barnett, D.B.

1998-09-01

The Hanford Site 200 Area Treated Effluent Disposal Facility (TEDF) has operated since June 1995. Groundwater monitoring has been conducted quarterly in the three wells surrounding the facility since 1992, with contributing data from nearby B Pond System wells. Cumulative hydrologic and geochemical information from the TEDF well network and other surrounding wells indicate no discernable effects of TEDF operations on the uppermost aquifer in the vicinity of the TEDF. The lateral consistency and impermeable nature of the Ringold Formation lower mud unit, and the contrasts in hydraulic conductivity between this unit and the vadose zone sediments of the Hanford formation suggest that TEDF effluent is spreading laterally with negligible mounding or downward movement into the uppermost aquifer. Hydrographs of TEDF wells show that TEDF operations have had no detectable effects on hydraulic heads in the uppermost aquifer, but show a continuing decay of the hydraulic mound generated by past operations at the B Pond System. Comparison of groundwater geochemistry from TEDF wells and other, nearby RCRA wells suggests that groundwater beneath TEDF is unique; different from both effluent entering TEDF and groundwater in the B Pond area. Tritium concentrations, major ionic proportions, and lower-than-background concentrations of other species suggest that groundwater in the uppermost aquifer beneath the TEDF bears characteristics of water in the upper basalt confined aquifer system. This report recommends retaining the current groundwater well network at the TEDF, but with a reduction of sampling/analysis frequency and some modifications to the list of constituents sought

Ground-Water Quality Data in the Kern County Subbasin Study Unit, 2006 - Results from the California GAMA Program

Science.gov (United States)

Shelton, Jennifer L.; Pimentel, Isabel; Fram, Miranda S.; Belitz, Kenneth

2008-01-01

the wells, and the results for these samples were used to evaluate the quality of the data from the ground-water samples. Assessment of the quality-control information resulted in censoring of less than 0.4 percent of the data collected for ground-water samples. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, raw ground water typically is treated, disinfected, or blended with other waters to maintain acceptable water quality. Regulatory thresholds apply, not to the raw ground water, but to treated water that is served to the consumer. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and the California Department of Public Health (CDPH), and as well as with thresholds established for aesthetic concerns (secondary maximum contaminant levels, SMCL-CA) by CDPH. VOCs and pesticides each were detected in approximately 60 percent of the grid wells, and detections of all compounds but one were below health-based thresholds. The fumigant, 1,2-dibromo-3-chloropropane (DBCP), was detected above the USEPA maximum contaminant level (MCL-US) in one sample. Detections of most inorganic constituents were also below health-based thresholds. Constituents detected above health-based thresholds include: nitrate, (MCL-US, 2 samples), arsenic (MCL-US, 2 samples), and vanadium (California notification level, NL-CA, 1 sample). All detections of radioactive constituents were below health-based thresholds, although nine samples had activities of radon-222 above the lower proposed MCL-US. Most of the samples from KERN wells had concentrations of major elements, total dissolved solids, and trace elements below the non-enforceable thresholds set for aesthetic concerns.

Core drilling of drillholes OL-PP66-69 at Olkiluoto 2008

International Nuclear Information System (INIS)

Kuusirati, J.; Tarvainen, A.-M.

2009-04-01

Suomen Malmi Oy (Smoy) core drilled four 24.88 - 25.39 m long investigation drillholes at Olkiluoto in June 2008. The identification numbers of the holes are OL-PP66, OL-PP67, OL-PP68 and OL-PP69. The drillholes are 75.7 mm by diameter. Drillholes were core drilled with the diamond drill rig Diamec 1000. The drilling water was taken from the ONKALO drilling water pipeline and premixed sodium fluorescein was used as a label agent in the drilling water. The labelled drilling water was driven to the drilling places in a tank. In addition to drilling the drill cores were logged and reported by geologist. During geological investigation the following parameters were logged: lithology, foliation, fracture parameters, fractured zones, core loss, weathering, fracture frequency, RQD and rock quality. The main rock types in the drillholes are diatexitic and veined gneisses and pegmatitic granite. The average fracture frequency in holes varied from 3.9 pcs/m to 5.8 pcs/m. The average RQD values varied from 84 % to 93 %. In the drillhole OL-PP66 two fractured zones were penetrated and in OL-PP69 one fractured zone. The drill cores OL-PP67 and OL-PP68 showed no fractured zones. Smoy also carried out optical imaging of the drillholes. The assignment included the field work and the data processing. This report describes the field operation, the equipment as well as the processing procedures and shows the obtained results and their quality. The raw and processed data are delivered digitally in WellCAD and PDF format. (orig.)

Sorption of radionuclides from spent fuel in crystalline rocks

International Nuclear Information System (INIS)

Nikula, A.

1982-10-01

The safe disposal of spent nuclear fuel or reprocessed waste is an essential element in the expansion of the nuclear power industry. Stable rock formations e.g. granite are considered to be potential sites for disposal. A major factor in evaluating the degree of safety of the disposal is the sorption of radionuclides in rock, which affects their retardation. The report considers the chemical forms of the hazardous radionuclides of spent nuclear fuel in groundwater and the effects of the water's properties on them. In the groundwater near the Olkiluoto power plant site cesium, strontium and radium are in cationic form, iodine as I - . Technetium would occur as TcO +2 , but the pertechnetate form is also possible. Uranium most probably would be as U(VI) plutonium and neptunium as Np(IV) or Np(V). The valences for thorium, americium and curium are not changed in this groundwater and would be +4, +3 and +3, respectively. The actinides in groundwater are all in hydrated or complex form. An increase on the ionic stregth of the groundwater in most instances causes a decrease in the sorption of nuclides since the ion exchange capacity of the rock is limited. Anionic ligands also decrease sorption of cations by complex formation. In some case, on the other hand, high salt concentrations may cause formation of radiocolloids of lanthanides and neptunium and thus increase sorption. In all cases the degree of sorption described by the distribution ratio Ksub(d) was influenced by the pH of the groundwater. Sorption of cesium and strontium increased with growing pH. The sorption behaviour of actinides was in positive correlation with formation of hydroxide complexes at different pH values. The Ksub(d) values of Cs, Sr, Co, Ni and Am for Olkiluoto granites were found to agree with Swedish values, also determined at ambient atmospheric conditions

Ground-Water Quality Data in the Middle Sacramento Valley Study Unit, 2006 - Results from the California GAMA Program

Science.gov (United States)

Schmitt, Stephen J.; Fram, Miranda S.; Milby Dawson, Barbara J.; Belitz, Kenneth

2008-01-01

, replicates, laboratory matrix spikes) were collected at approximately 10 percent of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a noticeable source of bias in the data for the ground-water samples. Differences between replicate samples were within acceptable ranges, indicating acceptably low variability. Matrix spike recoveries were within acceptable ranges for most constituents. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, or blended with other waters to maintain acceptable water quality. Regulatory thresholds apply to treated water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH) and thresholds established for aesthetic concerns (secondary maximum contaminant levels, SMCL-CA) by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only and are not indicative of compliance or noncompliance with regulatory thresholds. Most constituents that were detected in ground-water samples were found at concentrations below drinking-water thresholds. VOCs were detected in less than one-third and pesticides and pesticide degradates in just over one-half of the grid wells, and all detections of these constituents in samples from all wells of the MSACV study unit were below health-based thresholds. All detections of trace elements in samples from MSACV grid wells were below health-based thresholds, with the exceptions of arsenic and boro

Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

Science.gov (United States)

Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

2016-09-01

Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

A groundwater mass flux model for screening the groundwater-to-indoor-air exposure pathway

Energy Technology Data Exchange (ETDEWEB)

McHugh, T.; Blanc, P.C. de; Connor, J. [Groundwater Services Inc, Houston, TX (United States)

2003-07-01

The potential for human exposure via volatilisation of groundwater contaminants into indoor air has been a focus of increasing concern in recent years. At a small number of sites, elevated indoor vapour concentrations have been measured within buildings overlying shallow groundwater contaminated with chlorinated solvents, causing public concern over the potential for similar problems at other corrective action sites. In addition, use of the screening-levelmodel developed by Johnson and Ettinger (1991) for the groundwater-to-indoor-air exposure pathway has suggested that low microgram per litre (ug/L)-range concentrations of either chlorinated or non-chlorinated volatile organic compounds dissolved in groundwater could result in indoor vapour concentrations in excess of applicable risk-based exposure limits. As an alternative screening tool, this paper presents a groundwater mass flux model for evaluation of transport to indoor air. The mass flux model is intended to serve as a highly conservative screening tool that over-predicts groundwater-to-indoor-air mass flux, yet still provides sufficient sensitivity to identify sites for which the groundwater-to-indoor air exposure pathway is not a concern. (orig.)

Assessment of groundwater management at Hanford

International Nuclear Information System (INIS)

Deju, R.A.

1975-01-01

A comprehensive review of the groundwater management and environmental monitoring programs at the Hanford reservation was initiated in 1973. A large number of recommendations made as a result of this review are summarized. The purpose of the Hanford Hydrology Program is to maintain a groundwater surveillance network to assess contamination of the natural water system. Potential groundwater contamination is primarily a function of waste management decisions. The review revealed that although the hydrology program would greatly benefit from additional improvements, it is adequate to predict levels of contaminants present in the groundwater system. Studies are presently underway to refine advanced mathematical models to use results of the hydrologic investigation in forecasting the response of the system to different long-term management decisions. No information was found which indicates that a hazard through the groundwater pathway presently exists as a result of waste operations at Hanford. (CH)

Groundwater management based on monitoring of land subsidence and groundwater levels in the Kanto Groundwater Basin, Central Japan

Science.gov (United States)

Furuno, K.; Kagawa, A.; Kazaoka, O.; Kusuda, T.; Nirei, H.

2015-11-01

Over 40 million people live on and exploit the groundwater resources of the Kanto Plain. The Plain encompasses metropolitan Tokyo and much of Chiba Prefecture. Useable groundwater extends to the base of the Kanto Plain, some 2500 to 3000 m below sea level. Much of the Kanto Plain surface is at sea level. By the early 1970s, with increasing urbanization and industrial expansion, local overdraft of groundwater resources caused major ground subsidence and damage to commercial and residential structures as well as to local and regional infrastructure. Parts of the lowlands around Tokyo subsided to 4.0 m below sea level; particularly affected were the suburbs of Funabashi and Gyotoku in western Chiba. In the southern Kanto Plain, regulations, mainly by local government and later by regional agencies, led to installation of about 500 monitoring wells and almost 5000 bench marks by the 1990's. Many of them are still working with new monitoring system. Long-term monitoring is important. The monitoring systems are costly, but the resulting data provide continuous measurement of the "health" of the Kanto Groundwater Basin, and thus permit sustainable use of the groundwater resource.

The site selection process for a spent fuel repository in Finland. Summary report

Energy Technology Data Exchange (ETDEWEB)

McEwen, T. [EnvirosQuantiSci (United Kingdom); Aeikaes, T. [Posiva Oy, Helsinki (Finland)

2000-12-01

consequence of the change in primary legislation that resulted in spent fuel from the Loviisa power plant having to be disposed of in Finland, with the result that the island of Haestholmen was added to the list of potential disposal sites, is explained. The results of these detailed investigations are discussed in terms of the development of lithological and structural models of these sites, and with reference to the development of an understanding of their hydrogeological and hydrochemical environments and the generation of groundwater flow and hydrochemical models. These last two subjects are discussed with reference to their significance for spent fuel disposal. In addition, the constructability of the rock mass at these sites is described, including how a repository could be fitted into the rock mass, taking into account site-specific factors, in particular the location and orientation of fracture zones. The constructability of the Olkiluoto site is described in more detail. Other factors that could be of significance for site selection, namely future climate change and seismicity, are also discussed. The selection of Olkiluoto from these four sites is described with reference to the requirements of a disposal site, as specified by Government, and to factors such as long-term safety, the feasibility of repository development, the possibility of repository enlargement, repository operation, social acceptance, land usage and the environmental burden, infrastructure and costs. The conclusions of this analysis and the special issues at Olkiluoto, namely the presence and significance of saline water at depth and the modelling of groundwater flow, are discussed. The further investigations at Olkiluoto, in particular the main aspects to consider when planning the UCRF (Underground Rock Characterisation Facility) at the site, are presented with the aim of indicating the type of work that still needs to be done in order to demonstrate that a disposal facility can be constructed