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Sample records for controlling radionuclide releases

  1. Haw-glass dissolution and radionuclide release: mechanism - modelling - source term

    Energy Technology Data Exchange (ETDEWEB)

    Grambow, B [Forschungszentrum Karlsruhe, Institut fur Nukleare, Karlsruhe (Germany)

    1997-07-01

    Important release controlling processes are: 1) kinetics of glass matrix dissolution (leaching), 2) formation of secondary alteration products (controlling thermodynamic solubility), 3) sorption on surfaces in the engineered barrier system and 4) formation of mobile species. Quantification of these processes requires assessment of the energetics and dynamics of the various reversible and irreversible processes within an overall open non-equilibrium system. Corrosion/dissolution of the waste matrices is not necessarily associated with a proportional release of radionuclides. The formation of new secondary phases, such as silicates, molybdates, uranates, carbonates... establishes a new geochemical barrier for re-immobilization of radionuclides dissolved from the waste matrices. The presence of iron (corroding canisters during glass alteration) reduces the solution concentration of redox sensitive radionuclides. Consequently, the container, after being corroded, constitutes an important geochemical barrier for radionuclide re-immobilization. Geochemical modelling of the long-term behaviour of glasses must be performed in an integrated way, considering simultaneous reactions of the glass, of container corrosion, of repository rock and of backfill material. Until now, only few attempts were made for integral systems modelling. (A.C.)

  2. TURVA-2012: Formulation of radionuclide release scenarios

    International Nuclear Information System (INIS)

    Marcos, Nuria; Hjerpe, Thomas; Snellman, Margit; Ikonen, Ari; Smith, Paul

    2014-01-01

    TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR) and application for a construction licence for a repository for disposal of spent nuclear fuel at the Olkiluoto site in south-western Finland. This paper gives a summary of the scenarios and the methodology followed in formulating them as described in TURVA-2012: Formulation of Radionuclide Release Scenarios (Posiva, 2013). The scenarios are further analysed in TURVA-2012: Assessment of Radionuclide Release Scenarios for the Repository System and TURVA-2012: Biosphere Assessment (Posiva, 2012a, 2012b). The formulation of scenarios takes into account the safety functions of the main barriers of the repository system and the uncertainties in the features, events, and processes (FEP) that may affect the entire disposal system (i.e. repository system plus the surface environment) from the emplacement of the first canister until the far future. In the report TURVA-2012: Performance Assessment (2012d), the performance of the engineered and natural barriers has been assessed against the loads expected during the evolution of the repository system and the site. Uncertainties have been identified and these are taken into account in the formulation of radionuclide release scenarios. The uncertainties in the FEP and evolution of the surface environment are taken into account in formulating the surface environment scenarios used ultimately in estimating radiation exposure. Formulating radionuclide release scenarios for the repository system links the reports Performance Assessment and Assessment of Radionuclide Release Scenarios for the Repository System. The formulation of radionuclide release scenarios for the surface environment brings together biosphere description and the surface environment FEP and is the link to the assessment of the surface environment scenarios summarised in TURVA-2012: Biosphere Assessment. (authors)

  3. Radionuclide release calculations for SAR-08

    International Nuclear Information System (INIS)

    Thomson, Gavin; Miller, Alex; Smith, Graham; Jackson, Duncan

    2008-04-01

    Following a review by the Swedish regulatory authorities of the post-closure safety assessment of the SFR 1 disposal facility for low and intermediate waste (L/ILW), SAFE, the SKB has prepared an updated assessment called SAR-08. This report describes the radionuclide release calculations that have been undertaken as part of SAR-08. The information, assumptions and data used in the calculations are reported and the results are presented. The calculations address issues raised in the regulatory review, but also take account of new information including revised inventory data. The scenarios considered include the main case of expected behaviour of the system, with variants; low probability releases, and so-called residual scenarios. Apart from these scenario uncertainties, data uncertainties have been examined using a probabilistic approach. Calculations have been made using the AMBER software. This allows all the component features of the assessment model to be included in one place. AMBER has been previously used to reproduce results the corresponding calculations in the SAFE assessment. It is also used in demonstration of the IAEA's near surface disposal assessment methodology ISAM and has been subject to very substantial verification tests and has been used in verifying other assessment codes. Results are presented as a function of time for the release of radionuclides from the near field, and then from the far field into the biosphere. Radiological impacts of the releases are reported elsewhere. Consideration is given to each radionuclide and to each component part of the repository. The releases from the entire repository are also presented. The peak releases rates are, for most scenarios, due to organic C-14. Other radionuclides which contribute to peak release rates include inorganic C-14, Ni-59 and Ni-63. (author)

  4. Radionuclide release calculations for SAR-08

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, Gavin; Miller, Alex; Smith, Graham; Jackson, Duncan (Enviros Consulting Ltd, Wolverhampton (United Kingdom))

    2008-04-15

    Following a review by the Swedish regulatory authorities of the post-closure safety assessment of the SFR 1 disposal facility for low and intermediate waste (L/ILW), SAFE, the SKB has prepared an updated assessment called SAR-08. This report describes the radionuclide release calculations that have been undertaken as part of SAR-08. The information, assumptions and data used in the calculations are reported and the results are presented. The calculations address issues raised in the regulatory review, but also take account of new information including revised inventory data. The scenarios considered include the main case of expected behaviour of the system, with variants; low probability releases, and so-called residual scenarios. Apart from these scenario uncertainties, data uncertainties have been examined using a probabilistic approach. Calculations have been made using the AMBER software. This allows all the component features of the assessment model to be included in one place. AMBER has been previously used to reproduce results the corresponding calculations in the SAFE assessment. It is also used in demonstration of the IAEA's near surface disposal assessment methodology ISAM and has been subject to very substantial verification tests and has been used in verifying other assessment codes. Results are presented as a function of time for the release of radionuclides from the near field, and then from the far field into the biosphere. Radiological impacts of the releases are reported elsewhere. Consideration is given to each radionuclide and to each component part of the repository. The releases from the entire repository are also presented. The peak releases rates are, for most scenarios, due to organic C-14. Other radionuclides which contribute to peak release rates include inorganic C-14, Ni-59 and Ni-63. (author)

  5. Effects of sorption hysteresis on radionuclide releases from waste packages

    International Nuclear Information System (INIS)

    Barney, G.S.; Reed, D.T.

    1985-01-01

    A one-dimensional, numerical transport model was used to calculate radionuclide releases from waste packages emplaced in a nuclear waste repository in basalt. The model incorporates both sorption and desorption isotherm parameters measured previously for sorption of key radionuclides on the packing material component of the waste package. Sorption hysteresis as described by these isotherms lowered releases of some radionuclides by as much as two orders of magnitude. Radionuclides that have low molar inventories (relative to uranium), high solubility, and strongly sorbed, are most affected by sorption hysteresis. In these cases, almost the entire radionuclide inventory is sorbed on the packing material. The model can be used to help optimize the thickness of the packing material layer by comparing release rate versus packing material thickness curves with Nuclear Regulatory Commission (NRC) and Environmental Protection Agency (EPA) release limits

  6. Assessment of Radionuclides Release from Inshas LILW Disposal Facility Under Normal and Unusual Operational Conditions

    International Nuclear Information System (INIS)

    Zaki, A.A.

    2008-01-01

    Disposing of low and intermediate radioactive waste (LILW) is a big concern for Egypt due to the accumulated waste as a result of past fifty years of peaceful nuclear applications. Assessment of radionuclides release from Inshas LILW disposal facility under normal and unusual operational conditions is very important in order to apply for operation license of the facility. Aqueous release of radionuclides from this disposal facility is controlled by water flow, access of the water to the wasteform, release of the radionuclides from the wasteform, and transport to the disposal facility boundary. In this work, the release of 137 Cs , 6C o, and 90 Sr radionuclides from the Inshas disposal facility was studied under the change of operational conditions. The release of these radio contaminants from the source term to the unsaturated and saturated zones , to groundwater were studied. It was found that the concentration of radionuclides in a groundwater well located 150 m away from the Inshas disposal facility is less than the maximum permissible concentration in groundwater in both cases

  7. CRRIS, Health Risk Assessment from Atmospheric Releases of Radionuclides

    International Nuclear Information System (INIS)

    1999-01-01

    1 - Description of program or function: CRRIS consists of eight fully integrated computer codes which calculate environmental transport of atmospheric releases of radionuclides and resulting doses and health risks to individuals or populations. Each code may be used alone for various assessment applications. Because of its modular structure, CRRIS allows assessments to be tailored to the user's needs. Radionuclides are handled by CRRIS either in terms of the released radionuclides or the exposure radionuclides which consist of both the released nuclides and decay products that build up during environmental transport. Atmospheric dispersion calculations are performed by the ANEMOS computer code for distances less than 100 km and the RETADD-II computer code regional-scale distances. Both codes estimate annual-average air concentrations and ground deposition rates by location. SUMIT will translate and scale multiple ANEMOS runs onto a master grid. TERRA reads radionuclide air concentrations and deposition rates to estimate concentrations of radionuclides in food and surface soil. Radiologic decay and ingrowth, soil leaching, and transport through the food chain are included in the calculations. MLSOIL computes an effective radionuclide ground-surface concentration to be used in computing external health effects. The five-layer model of radionuclide transport through soil in MLSOIL provides an alternative to the single-layer model used in TERRA. DFSOIL computes dose factors used in MLSOIL to compute doses from the five soil layers and from the ground surface. ANDROS reads environmental concentrations of radionuclides computed by the other CRRIS codes and produces tables of doses and risks to individuals or populations from atmospheric releases of radionuclides. 2 - Method of solution: SUMIT performs geometric interpolation. TERRA and MLSOIL are terrestrial transport compartment models. DFSOIL computes soil-layer-specific dose factors based on the point-kernel method

  8. Radionuclide releases from natural analogues of spent nuclear fuel

    International Nuclear Information System (INIS)

    Curtis, D.B.; Fabryka-Martin, J.; Dixon, P.; Aguilar, R.; Rokop, D.; Cramer, J.

    1993-01-01

    Measures of 99 Tc, 129 I, 239 Pu and U concentrations in rock samples from uranium deposits at Cigar Lake and Koongarra have been used to study processes of radionuclide release from uranium minerals. Rates of release have been immeasurably slow at Cigar Lake. At Koongarra release rates appear to have been faster, producing small deficiencies of 99 Tc, and larger ones of 129 I. The inferred differences in radionuclide release rates are consistent with expected differences in uranium mineral degradation rates produced by the differing hydrogeochemical environments at the two sites

  9. Biological implications of radionuclides released from nuclear industries

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1979-08-15

    The development of nuclear power technologies has led to a rapid increase in the number of reactors and other installations including fuel reprocessing and radioactive waste treatment plants in operation. Associated with these developments are the concomitant possibilities for release of radionuclides in the environment, which in turn might exert some biological impacts including late somatic and genetic effects on man. The principal objective of the Agency's symposium was, therefore, to review critically the current information on the biological effects of exposure to low levels of incorporated radionuclides and the radiation doses absorbed from them. The purpose of this review was to provide a sound scientific basis on which to evaluate radiation safety standards, risk-benefit analysis, as well as the regulatory control and management of nuclear wastes. The major part of the discussions centered around the problems of the radiobiology, radio-oncology, radio-ecology and toxicology of the transuranic such as such as plutonium, americium, curium as well as radionuclide species like tritium, krypton and iodine among others, which are expected to be released from these nuclear installations. Current data and practical information obtained through suitably designed animal studies and also from epidemiological, ecological and food-chain analyses and other relevant follow-up surveys of late effects in accidentally exposed occupational personnel were reported for discussion and risk evaluation.

  10. CRRIS: a methodology for assessing the impact of airborne radionuclide releases

    International Nuclear Information System (INIS)

    Baes, C.F. III; Miller, C.W.

    1983-01-01

    The Computerized Radiological Risk Investigation System (CRRIS) consists of six fully integrated computer codes which calculate environmental transport and resulting doses and risks to individuals or populations exposed to atmospheric radionuclide releases. The individual codes may be used alone for various assessment applications or may be run as a system. This presentation provides an overview and introduction to this system of computer codes and their use in conducting nuclear assessments. Radionuclides are handled by CRRIS either in terms of the released radionuclides or in terms of exposure radionuclides which consist of both the released nuclides and all (or a subset of) the decay daughters that grow in during environmental transport. The capability of CRRIS to handle radionuclide chains is accomplished through PRIMUS which serves as a preprocessor by accessing a library of radionuclide decay data and sets up matricies of decay constants which are used by the other CRRIS codes in all calculations involving transport and decay. PRIMUS may also be run independently by the user to define the decay chains, radionuclide decay constants, and branching ratios

  11. Accidental releases of radionuclides: a preliminary study of the consequences of land contamination

    International Nuclear Information System (INIS)

    Simmonds, J.R.; Haywood, S.M.; Linsley, G.S.

    1982-10-01

    The long term consequences of land contamination from accidental releases of activity from thermal reactors are examined. The radiological consequences are assessed using an analysis of the exposure of individuals and the population to ground deposits of the radionuclides released. The contribution of the different nuclides in the release by their various exposure routes to the irradiation of man are calculated as a function of time after release and the most radiologically important are identified. A preliminary assessment is made of off-site economic and social consequences of accidental releases by estimating the areas of land which would be affected by the introduction of countermeasures to control individual radiation exposure due to external irradiation from ground deposits (relocation of populations), and the intake of radionuclides contained in locally produced foodstuffs (restrictions on food production). The areas where administrative controls would be necessary decline in size with time after the release; estimates are made of this time-dependent behaviour using dynamic environmental transfer models. Finally, the collective doses saved by the introduction of countermeasures are estimated using population and agricultural distribution data for a rural location in the United Kingdom. (author)

  12. Radionuclide release from research reactor spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Curtius, H., E-mail: h.curtius@fz-juelich.de [Forschungszentrum Juelich, Institut fuer Energieforschung, IEF-6 Sicherheitsforschung und Reaktortechnik, Geb. 05.3, D-52425 Juelich (Germany); Kaiser, G.; Mueller, E.; Bosbach, D. [Forschungszentrum Juelich, Institut fuer Energieforschung, IEF-6 Sicherheitsforschung und Reaktortechnik, Geb. 05.3, D-52425 Juelich (Germany)

    2011-09-01

    Numerous investigations with respect to LWR fuel under non oxidizing repository relevant conditions were performed. The results obtained indicate slow corrosion rates for the UO{sub 2} fuel matrix. Special fuel-types (mostly dispersed fuels, high enriched in {sup 235}U, cladded with aluminium) are used in German research reactors, whereas in German nuclear power plants, UO{sub 2}-fuel (LWR fuel, enrichment in {sup 235}U up to 5%, zircaloy as cladding) is used. Irradiated research reactor fuels contribute less than 1% to the total waste volume. In Germany, the state is responsible for fuel operation and for fuel back-end options. The institute for energy research (IEF-6) at the Research Center Juelich performs investigation with irradiated research reactor spent fuels under repository relevant conditions. In the study, the corrosion of research reactor spent fuel has been investigated in MgCl{sub 2}-rich salt brine and the radionuclide release fractions have been determined. Leaching experiments in brine with two different research reactor fuel-types were performed in a hot cell facility in order to determine the corrosion behaviour and the radionuclide release fractions. The corrosion of two dispersed research reactor fuel-types (UAl{sub x}-Al and U{sub 3}Si{sub 2}-Al) was studied in 400 mL MgCl{sub 2}-rich salt brine in the presence of Fe{sup 2+} under static and initially anoxic conditions. Within these experimental parameters, both fuel types corroded in the experimental time period of 3.5 years completely, and secondary alteration phases were formed. After complete corrosion of the used research reactor fuel samples, the inventories of Cs and Sr were quantitatively detected in solution. Solution concentrations of Am and Eu were lower than the solubility of Am(OH){sub 3}(s) and Eu(OH){sub 3}(s) solid phases respectively, and may be controlled by sorption processes. Pu concentrations may be controlled by Pu(IV) polymer species, but the presence of Pu(V) and Pu

  13. Radionuclide releases to the Columbia River from Hanford Operations, 1944--1971

    International Nuclear Information System (INIS)

    Heeb, C.M.; Bates, D.J.

    1994-05-01

    The purpose of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that individuals could have received as a result of radionuclide emissions since 1944 from the Hanford Site. One source of radionuclide releases to the Columbia River was from production reactor operations. This report provides a quantitative estimate of the amount of radioactivity released each month (1944--1971) to the Columbia River from eleven radionuclides as well as from gross beta activity

  14. Building shielding effects on radiation doses from routine radionuclide releases

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1977-01-01

    In calculating population doses from the release of radionuclides to the atmosphere, it is usually assumed that man spends all of his time outdoors standing on a smooth infinite plane. Realistically, however, man spends most of the time indoors, so that substantial reductions in radiation doses may result compared with the usual estimates. Calculational models were developed to study the effects of building structures on radiation doses from routine releases of radionuclides to the atmosphere. Both internal dose from inhaled radionuclides and external photon dose from airborne and surface-deposited radionuclides are considered. The effect of building structures is described quantitatively by a dose reduction factor, which is the ratio of the dose inside a structure to the corresponding dose with no structure present. The internal dose from inhaled radionuclides is proportional to the radionuclide concentration in the air. Assuming that the outdoor airborne concentration is constant with time, the time-dependence of the indoor airborne concentration in terms of the structure air ventilation rate, the deposition velocities for radionuclides on the inside floor, walls, and ceiling, and the radioactive decay constant, were calculated

  15. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

    International Nuclear Information System (INIS)

    Grabaskas, David; Bucknor, Matthew; Jerden, James

    2016-01-01

    The development of an accurate and defensible mechanistic source term will be vital for the future licensing efforts of metal fuel, pool-type sodium fast reactors. To assist in the creation of a comprehensive mechanistic source term, the current effort sought to estimate the release fraction of radionuclides from metal fuel pins to the primary sodium coolant during fuel pin failures at a variety of temperature conditions. These release estimates were based on the findings of an extensive literature search, which reviewed past experimentation and reactor fuel damage accidents. Data sources for each radionuclide of interest were reviewed to establish release fractions, along with possible release dependencies, and the corresponding uncertainty levels. Although the current knowledge base is substantial, and radionuclide release fractions were established for the elements deemed important for the determination of offsite consequences following a reactor accident, gaps were found pertaining to several radionuclides. First, there is uncertainty regarding the transport behavior of several radionuclides (iodine, barium, strontium, tellurium, and europium) during metal fuel irradiation to high burnup levels. The migration of these radionuclides within the fuel matrix and bond sodium region can greatly affect their release during pin failure incidents. Post-irradiation examination of existing high burnup metal fuel can likely resolve this knowledge gap. Second, data regarding the radionuclide release from molten high burnup metal fuel in sodium is sparse, which makes the assessment of radionuclide release from fuel melting accidents at high fuel burnup levels difficult. This gap could be addressed through fuel melting experimentation with samples from the existing high burnup metal fuel inventory.

  16. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-01

    The development of an accurate and defensible mechanistic source term will be vital for the future licensing efforts of metal fuel, pool-type sodium fast reactors. To assist in the creation of a comprehensive mechanistic source term, the current effort sought to estimate the release fraction of radionuclides from metal fuel pins to the primary sodium coolant during fuel pin failures at a variety of temperature conditions. These release estimates were based on the findings of an extensive literature search, which reviewed past experimentation and reactor fuel damage accidents. Data sources for each radionuclide of interest were reviewed to establish release fractions, along with possible release dependencies, and the corresponding uncertainty levels. Although the current knowledge base is substantial, and radionuclide release fractions were established for the elements deemed important for the determination of offsite consequences following a reactor accident, gaps were found pertaining to several radionuclides. First, there is uncertainty regarding the transport behavior of several radionuclides (iodine, barium, strontium, tellurium, and europium) during metal fuel irradiation to high burnup levels. The migration of these radionuclides within the fuel matrix and bond sodium region can greatly affect their release during pin failure incidents. Post-irradiation examination of existing high burnup metal fuel can likely resolve this knowledge gap. Second, data regarding the radionuclide release from molten high burnup metal fuel in sodium is sparse, which makes the assessment of radionuclide release from fuel melting accidents at high fuel burnup levels difficult. This gap could be addressed through fuel melting experimentation with samples from the existing high burnup metal fuel inventory.

  17. Radionuclides and isotopes release of spent fuel matrix. Conceptual and mathematical models of wastes behaviour

    International Nuclear Information System (INIS)

    Cera, E.; Merino, J.; Bruno, J.

    2000-01-01

    We have developed a conceptual and numerical model to calculate release of selected radionuclides from spent fuel under repository condition. This has been done in the framework of the Enresa 2000 performance assessment exercise. The model has been developed based on kinetic mass balance equations in order to study the evolution of the spent fuel water interface as a function of time. Several processes have been kinetically modelled: congruent dissolution, radioactive decay, ingrowth and water turnover in the gap. The precipitation/redissolution of secondary solid phases has been taken into account from a thermodynamic point of view. Both approaches have been coupled and the resulting equations solved for a number of radionuclides in both, a conservative and realistic approach. The results show three distinct groups of radionuclides based on their release behaviour: a first group is composed of radioisotopes of highly insoluble elements (e. g., Pu, Am, Pd) whose concentration in the gap is mainly controlled by their solubility and therefore their evolution is identical in both cases. Secondly, a set of radionuclides from soluble elements under these conditions (e. g., I, Cs, Ra) show concentrations kinetically controlled, decreasing with time following the congruent dissolution trend. Their release concentrations are one order of magnitude larger in the conservative case than in the realistic case. Finally, a third group has been identified (e. g., Se, Th, Cm) where a mixed behaviour takes place: initially their solubility limiting phases control their concentration in the gap but the situation reverts to a kinetic control as the chemical conditions change and the secondary precipitates become totally dissolved. The fluxes of the different radionuclides are also given as an assessment of the source term in the performance assessment. (Author)

  18. Cycle of radionuclides released into waters by the nuclear industry

    International Nuclear Information System (INIS)

    Bovard, A.; Grauby, A.

    1975-01-01

    A review is made of the main radionuclides released by nuclear industry into the aquatic environment. The water-sediment interactions, the uptake of radionuclides by aquatic organisms and the problem of irrigation water are considered [fr

  19. Radionuclide release from PWR spent fuel specimens with induced cladding defects

    International Nuclear Information System (INIS)

    Wilson, C.N.; Oversby, V.M.

    1984-03-01

    Radionuclide releases from pressurized water reactor (PWR) spent fuel rod specimens containing various artificially induced cladding defects were compared by leach testing. The study was conducted in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) Waste Package Task to evaluate the effectiveness of failed cladding as a barrier to radionuclide release. Test description and results are presented

  20. Radionuclide release from PWR spent fuel specimens with induced cladding defects

    International Nuclear Information System (INIS)

    Wilson, C.N.; Oversby, V.M.

    1984-03-01

    Radionuclide releases from pressurized water reactor (PWR) spent fuel rod specimens containing various artificially induced cladding defects were compared by leach testing. The study was conducted in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) Waste Package Task to evaluate the effectiveness of failed cladding as a barrier to radionuclide release. Test description and results are presented. 6 references, 4 figures

  1. Risk-informed assessment of radionuclide release from dissolution of spent nuclear fuel and high-level waste glass

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Tae M., E-mail: tae.ahn@nrc.gov

    2017-06-15

    Highlights: • Dissolution of HLW waste form was assessed with long-term risk informed approach. • The radionuclide release rate decreases with time from the initial release rate. • Fast release radionuclides can be dispersed with discrete container failure time. • Fast release radionuclides can be restricted by container opening area. • Dissolved radionuclides may be further sequestered by sorption or others means. - Abstract: This paper aims to detail the different parameters to be considered for use in an assessment of radionuclide release. The dissolution of spent nuclear fuel and high-level nuclear waste glass was considered for risk and performance insights in a generic disposal system for more than 100,000 years. The probabilistic performance assessment includes the waste form, container, geology, and hydrology. Based on the author’s previous extended work and data from the literature, this paper presents more detailed specific cases of (1) the time dependence of radionuclide release, (2) radionuclide release coupled with container failure (rate-limiting process), (3) radionuclide release through the opening area of the container and cladding, and (4) sequestration of radionuclides in the near field after container failure. These cases are better understood for risk and performance insights. The dissolved amount of waste form is not linear with time but is higher at first. The radionuclide release rate from waste form dissolution can be constrained by container failure time. The partial opening area of the container surface may decrease radionuclide release. Radionuclides sequestered by various chemical reactions in the near field of a failed container may become stable with time as the radiation level decreases with time.

  2. Radionuclides release possibility analysis of MSR at various accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choong Wie; Kim, Hee Reyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    There are some accidents which go beyond our expectation such as Fukushima Daiichi nuclear disaster and amounts of radionuclides release to environment, so more effort and research are conducted to prevent it. MSR (Molten Salt Reactor) is one of GEN-IV reactor types, and its coolant and fuel are mixtures of molten salt. MSR has a schematic like figure 1 and it has different features with the solid fuel reactor, but most important and interesting feature of MSR is its many safety systems. For example, MSR has a large negative void coefficient. Even though power increases, the reactor slows down soon. Radionuclides release possibility of MSR was analyzed at various accident conditions including Chernobyl and Fukushima ones. The MSR was understood to prevent the severe accident by the negative reactivity coefficient and the absence of explosive material such as water at the Chernobyl disaster condition. It was expected to contain fuel salts in the reactor building and not to release radionuclides into environment even if the primary system could be ruptured or broken and fuel salts would be leaked at the Fukushima Daiichi nuclear disaster condition of earthquake and tsunami. The MSR, which would not lead to the severe accident and therefore prevents the fuel release to the environment at many expected scenarios, was thought to have priority in the aspect of accidents. A quantitative analysis and a further research are needed to evaluate the possibility of radionuclide release to the environment at the various accident conditions based on the simple comparison of the safety feature between MSR and solid fuel reactor.

  3. Modelling the dispersion of radionuclides following short duration releases to rivers

    International Nuclear Information System (INIS)

    Smith, J.T.; Bowes, M.; Denison, F.H.

    2003-01-01

    This project develops a model for assessing short duration liquid discharges of radionuclides to rivers. The assessment of doses arising from discharges to rivers is normally carried out by considering annual average discharge rates. Actual authorised discharges, however, may occur unevenly during the year or relatively high short-term discharges could occur in the unlikely event of an incident. Short term radionuclide releases could potentially result in temporary increases in radionuclide activity concentrations in water and fish which are greater than those resulting from a continuous discharge. The purpose of this project is to develop a model to assess short term releases from these sites, and where possible develop generic methods of assessing short term releases. An advection-dispersion model was developed to predict the concentrations of radionuclides in the river environment, ie in river water, river bed sediment and in predatory fish. Uptake of radionuclides to fish was modelled by estimating rates of uptake of radionuclides via the aquatic food chain or across the gill, as appropriate. The model was used to predict the concentrations of the radionuclides in the river Thames and its tributaries as a result of short duration discharges into stretches of the Thames and River Colne. Model output is given as a series of graphs of activity concentration and time integrated activity concentration resulting from a 1 MBq discharge for the following release durations: 5 minutes, 1 h, 3 h, 12 h and 24 h. The five locations for which predictions are given were 100m, 300m, 1000m, 3000m and 10000m downstream. The river volumetric flow rate was shown to be the most important environmental variable determining activity concentrations in water, fish and sediments following a release. In general, the maximum and integrated activity concentrations in water and fish will be in inverse proportion to the river volumetric flow rate, for a given amount and duration of release

  4. Radionuclide release from spent fuel under geologic disposal conditions: An overview of experimental and theoretical work through 1985

    Energy Technology Data Exchange (ETDEWEB)

    Reimus, P.W.; Simonson, S.A.

    1988-04-01

    This report presents an overview of experimental and theoretical work on radionuclide release from spent fuel and uranium dioxide (UO/sub 2/) under geologic disposal conditions. The purpose of the report is to provide a source book of information that can be used to develop models that describe radionuclide release from spent fuel waste packages. Modeling activities of this nature will be conducted within the Waste Package Program (WPP) of the Department of Energy's Salt Repository Project (SRP). The topics discussed include experimental methods for investigating radionuclide release, how results have been reported from radionuclide release experiments, theoretical studies of UO/sub 2/ and actinide solubility, results of experimental studies of radionuclide release from spent fuel and UO/sub 2/ (i.e., the effects of different variables on radionuclide release), characteristics of spent fuel pertinent to radionuclide release, and status of modeling of radionuclide release from spent fuel. Appendix A presents tables of data from spent fuel radionuclide release experiments. These data have been digitized from graphs that appear in the literature. An annotated bibliography of literature on spent fuel characterization is provided in Appendix B.

  5. Introduction to CRRIS: a computerized radiological risk investigation system for assessing atmospheric releases of radionuclides

    International Nuclear Information System (INIS)

    Baes, C.F. III; Miller, C.W.; Kocher, D.C.; Sjoreen, A.L.; Murphy, B.D.

    1985-08-01

    The CRRIS is a Computerized Radiological Risk Investigation System consisting of eight fully integrated computer codes which calculate environmental transport of atmospheric releases of radionuclides and resulting doses and health risks to individuals or populations. Each code may also be used alone for various assessment applications. Radionuclides are handled by the CRRIS either in terms of the released radionuclides or the exposure radionuclides which consist of both the released nuclides and decay products that grow in during environmental transport. The CRRIS is not designed to simulate short-term effects. 51 refs

  6. Development of a mechanistic model for release of radionuclides from spent fuel in brines: Salt Repository Project

    International Nuclear Information System (INIS)

    Reimus, P.W.; Windisch, C.F.

    1988-03-01

    At present there are no comprehensive mechanistic models describing the release of radionuclides from spent fuel in brine environments. This report provides a comprehensive review of the various factors that can affect radionuclide release from spent fuel, suggests a modeling approach, and discusses proposed experiments for obtaining a better mechanistic understanding of the radionuclide release processes. Factors affecting radionuclide release include the amount, location, and disposition of radionuclides in the fuel and environmental factors such as redox potential, pH, the presence of complexing anions, temperature, and radiolysis. It is concluded that a model describing the release of radionuclides from spent fuel should contain separate terms for release from the gap, grain boundaries, and grains of the fuel. Possible functional forms for these terms are discussed in the report. Experiments for assessing their validity and obtaining key model parameters are proposed. 71 refs., 4 figs., 6 tabs

  7. Impacts of uranium-utilization improvements on light-water-reactor radionuclide releases

    International Nuclear Information System (INIS)

    Aaberg, R.L.

    1981-08-01

    This report discusses potential changes to radionuclide releases as a result of uranium-saving plant modifications and altered operating practices. Only releases to the environment from routine operation are considered; releases resulting from abnormal conditions outside the technical specifications covering plant operation are not considered

  8. The fast multiple-path NUCTRAN model -- Calculating the radionuclide release from a repository

    International Nuclear Information System (INIS)

    Romero, L.; Moreno, L.; Neretnieks, I.

    1995-01-01

    The NUCTRAN model has been applied to the Swedish KBS-3 nuclear waste repository concept, where the migration of radionuclides is through various barriers and pathways. The escape of the nuclides from the canister occurs through a small hole. This hole controls the release of nuclides from the repository. NUCTRAN is a useful tool to calculate the nonstationary transport in a repository for high-level nuclear waste. The advantage of this model is the use of a coarse compartmentalization of the repository, which makes it flexible and easy to adapt to different geometries. The several radionuclide release calculations made with NUCTRAN have shown the capability of this to handle different situations rapidly and easily. The particularity of these calculations is the high accuracy obtained by using a coarse compartmentalization of the Swedish KBS-3 repository and the small requirements of computing time. At short times for short-lived nuclides, the calculated releases are exaggerated. The error can be considerably reduced by an additional subdivision of large compartments into a few compartments

  9. Mathematical modeling of radionuclide release through a borehole in a radioactive waste repository

    International Nuclear Information System (INIS)

    Choi, Heui Joo

    1996-02-01

    The effects of inadvertent human intrusion as a form of direct drilling into a radioactive waste repository are discussed in this thesis. It has been mentioned that the inadvertent direct drilling into the repository could provide a release pathway for radionuclides even with its low occurrence probability. The following analyses are carried out regarding the problem. The maximum concentration in a water-filled borehole penetrating a repository is computed with a simple geometry. The modeling is based upon the assumption of the diffusive mass transfer in the waste forms and the complete mixing in the borehole. It is shown that the maximum concentrations of six radionuclides in the borehole could exceed the Maximum Permissible Concentration. Also, the diffusive mass transport in a water-filled borehole is investigated with a solubility-limited boundary condition. An analytic solution is derived for this case. Results show that the diffusive mass transport is fast enough to justify the assumption of the complete mixing compared with the considered time span. The axial diffusive mass transport along a water-filled borehole is modeled to compute the release rate taking account of the rock matrix diffusion. The results show that the release of short-lived radionuclides are negligible due to the low concentration gradient in early time and the rock matrix diffusion. The release rates of four long-lived radionuclides are computed. It is also shown that the model developed could be applied to a borehole at a non-cylindrically shaped repository and the off-center drilling of a cylindrical repository. The release rates of long-lived nuclides through a porous material-filled borehole are computed. The results show that the release of all the long-lived nuclides is negligible up to half million years in the case that the borehole is filled with the porous material. The radiological effects of the nuclides released through the borehole penetrating the repository are computed

  10. Radionuclide Release after LBLOCA with Loss of Class IV Power Accident in CANDU-6 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hoon [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    A large break in a pipe train of a primary heat transport system discharges coolant, which has high energy and large mass, into the containment building. Reactor shutdown and emergency core cooling water will limit the fuel cladding failure, but cannot prevent it entirely. The containment building is the last barrier of radionuclide release to the environment. Containment isolation and pressure suppression by dousing and local air cooler reduce the amount of radionuclide release to the environment. The objective of containment behavior analysis for large break loss of coolant with loss of class IV power accident is to assess the amount of radionuclide release to the ambient atmosphere. Radionuclide release rates in this event, with all safety system available, that is, the containment building is intact, as well as with containment system impairment, are analyzed with GOTHIC and SMART code

  11. Radionuclide release from low-level waste in field lysimeters

    International Nuclear Information System (INIS)

    Oblath, S.B.

    1986-01-01

    A field program has been in operation for 8 years at the Savannah River Plant (SRP) to determine the leaching/migration behavior of low-level radioactive waste using lysimeters. The lysimeters are soil-filled caissons containing well characterized wastes, with each lysimeter serving as a model of a shallow land burial trench. Sampling and analysis of percolate water and vegetation from the lysimeters provide a determination of the release rates of the radionuclides from the waste/soil system. Vegetative uptake appears to be a major pathway for migration. Fractional release rates from the waste/soil system are less than 0.01% per year. Waste-to-soil leach rates up to 10% per year have been determined by coring several of the lysimeters. The leaching of solidified wasteforms under unsaturated field conditions has agreed well with static, immersion leaching of the same type waste in the laboratory. However, releases from the waste/soil system in the lysimeter may be greater than predicted based on leaching alone, due to complexation of the radionuclides by other components leached from the wastes to form mobile, anionic species

  12. Effect of buffer thickness on the retardation of radionuclide release from the high-level waste repository

    International Nuclear Information System (INIS)

    Cho, Won Jin; Lee, Jae Owan; Kang, Chul Hyung; Han, Kyung Won

    2000-12-01

    The radionuclide release from buffer in the high-level waste repository to the surrounding host rock was assessed, and the effect of the radial buffer thickness on the release rate was analyzed. The total release rates decrease sharply with increasing radial buffer thickness up to 0.25 m, and decrease moderately at the buffer thickness between 0.25 m and 0.5 m. But increasing the radial buffer thickness beyond 0.5 m has little effect in reducing radionuclide release. Therefore a radial buffer thickness between 0.25 m and 0.5 m is sufficient based on the viewpoint of radionuclide retention

  13. Sensitivity analysis of biospheric behaviour of radionuclides released from nuclear waste repositories

    International Nuclear Information System (INIS)

    Korhonen, R.; Savolainen, I.; Suolanen, V.

    1985-01-01

    Sensitivity studies of biospheric behaviour of radionuclides released from a planned spent nuclear fuel repository are performed. Sensitivity of radionuclide concentrations in biosphere and that of radiation doses to solubility of nuclides, to sedimentation rate and to intercompartmental water exchange are studied. Solubility has pronounced effect on the sedimentation on the local scale, and in general, sediment sinks were found to be of major importance in the biospheric behaviour of radionuclides. (author)

  14. Health impacts of large releases of radionuclides. Proceedings

    International Nuclear Information System (INIS)

    Lake, J.V.; Bock, G.R.; Cardew, Gail

    1997-01-01

    There have been various large-scale releases of radionuclides into the environment in the 20th century. Some of these have been accidental and some deliberate. In order to minimize the risk to human health of such releases, it is important that we understand how these substances are transported throughout the terrestrial and aquatic environments and the ways in which they can ultimately affect human health. This book contains contributions from the world's leading radioecologists and health scientists who discuss the progress in understanding these transport processes and exposure pathways of radionuclides to humans; the problems and latest techniques of quantitating retrospectively the actual doses received by individuals; the time course of effects of exposure in relation to structure and function at the cellular tissue, organ and whole organism level; the genetic effects, and effects on reproductive health, in populations and individuals, including fetal effects in pregnant women and inherited genetic effects; and scientific approaches to evaluate the important problem of the mental health consequences of perceived risk of radiation damage to health. (author)

  15. Radionuclide release rates from spent fuel for performance assessment modeling

    International Nuclear Information System (INIS)

    Curtis, D.B.

    1994-01-01

    In a scenario of aqueous transport from a high-level radioactive waste repository, the concentration of radionuclides in water in contact with the waste constitutes the source term for transport models, and as such represents a fundamental component of all performance assessment models. Many laboratory experiments have been done to characterize release rates and understand processes influencing radionuclide release rates from irradiated nuclear fuel. Natural analogues of these waste forms have been studied to obtain information regarding the long-term stability of potential waste forms in complex natural systems. This information from diverse sources must be brought together to develop and defend methods used to define source terms for performance assessment models. In this manuscript examples of measures of radionuclide release rates from spent nuclear fuel or analogues of nuclear fuel are presented. Each example represents a very different approach to obtaining a numerical measure and each has its limitations. There is no way to obtain an unambiguous measure of this or any parameter used in performance assessment codes for evaluating the effects of processes operative over many millennia. The examples are intended to suggest by example that in the absence of the ability to evaluate accuracy and precision, consistency of a broadly based set of data can be used as circumstantial evidence to defend the choice of parameters used in performance assessments

  16. Model to estimate the local radiation doses to man from the atmospheric release of radionuclides (LWBR development program)

    International Nuclear Information System (INIS)

    Rider, J.L.; Beal, S.K.

    1977-04-01

    A model was developed to estimate the radiation dose commitments received by people in the vicinity of a facility that releases radionuclides into the atmosphere. This model considers dose commitments resulting from immersion in the plume, ingestion of contaminated food, inhalation of gaseous and suspended radioactivity, and exposure to ground deposits. The dose commitments from each of these pathways is explicitly considered for each radionuclide released into the atmosphere and for each daughter of each released nuclide. Using the release rate of only the parent radionuclide, the air and ground concentrations of each daughter are calculated for each position of interest. This is considered to be a significant improvement over other models in which the concentrations of daughter radionuclides must be approximated by separate releases

  17. Pathways to man for radionuclides released from disposal sites on land

    International Nuclear Information System (INIS)

    Hill, M.D.

    1986-01-01

    To predict the potential radiological impact on man of the disposal of radioactive wastes it is necessary to identify all the events and processes that could cause releases of radionuclides into the environment, to estimate their probabilities of occurrence and to calculate their consequences, for both individuals and populations. This paper briefly reviews the types of releases that have to be considered for land disposal sites and describes the mathematical models used to calculate rates of transport of radionuclides through the environment and doses to man. The difficulties involved in predicting environmental conditions in the far future are discussed, in the light of the ways in which the results of consequence calculations will be used. Assessments of land disposal of long-lived and highly radioactive wastes are briefly reviewed, with the aim of identifying the most important radionuclides and exposure pathways, and the areas where the models and their databases require improvement. (author)

  18. Inverse modelling of radionuclide release rates using gamma dose rate observations

    Science.gov (United States)

    Hamburger, Thomas; Evangeliou, Nikolaos; Stohl, Andreas; von Haustein, Christoph; Thummerer, Severin; Wallner, Christian

    2015-04-01

    Severe accidents in nuclear power plants such as the historical accident in Chernobyl 1986 or the more recent disaster in the Fukushima Dai-ichi nuclear power plant in 2011 have drastic impacts on the population and environment. Observations and dispersion modelling of the released radionuclides help to assess the regional impact of such nuclear accidents. Modelling the increase of regional radionuclide activity concentrations, which results from nuclear accidents, underlies a multiplicity of uncertainties. One of the most significant uncertainties is the estimation of the source term. That is, the time dependent quantification of the released spectrum of radionuclides during the course of the nuclear accident. The quantification of the source term may either remain uncertain (e.g. Chernobyl, Devell et al., 1995) or rely on estimates given by the operators of the nuclear power plant. Precise measurements are mostly missing due to practical limitations during the accident. The release rates of radionuclides at the accident site can be estimated using inverse modelling (Davoine and Bocquet, 2007). The accuracy of the method depends amongst others on the availability, reliability and the resolution in time and space of the used observations. Radionuclide activity concentrations are observed on a relatively sparse grid and the temporal resolution of available data may be low within the order of hours or a day. Gamma dose rates, on the other hand, are observed routinely on a much denser grid and higher temporal resolution and provide therefore a wider basis for inverse modelling (Saunier et al., 2013). We present a new inversion approach, which combines an atmospheric dispersion model and observations of radionuclide activity concentrations and gamma dose rates to obtain the source term of radionuclides. We use the Lagrangian particle dispersion model FLEXPART (Stohl et al., 1998; Stohl et al., 2005) to model the atmospheric transport of the released radionuclides. The

  19. Simplified analytical model to simulate radionuclide release from radioactive waste trenches

    International Nuclear Information System (INIS)

    Sa, Bernardete Lemes Vieira de

    2001-01-01

    In order to evaluate postclosure off-site doses from low-level radioactive waste disposal facilities, a computer code was developed to simulate the radionuclide released from waste form, transport through vadose zone and transport in the saturated zone. This paper describes the methodology used to model these process. The radionuclide released from the waste is calculated using a model based on first order kinetics and the transport through porous media was determined using semi-analytical solution of the mass transport equation, considering the limiting case of unidirectional convective transport with three-dimensional dispersion in an isotropic medium. The results obtained in this work were compared with other codes, showing good agreement. (author)

  20. Radionuclide releases to the atmosphere from Hanford Operations, 1944--1972. Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Heeb, C.M.

    1994-05-01

    The purpose of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation dose that individuals could have received as a result of radionuclide emissions since 1944 from the Hanford Site. The first step in determining dose is to estimate the amount and timing of radionuclide releases to air and water. This report provides the air release information.

  1. Modeling of container failure and radionuclide release from a geologic nuclear waste repository

    International Nuclear Information System (INIS)

    Kim, Chang Lak; Kim, Jhin Wung; Choi, Kwang Sub; Cho, Chan Hee

    1989-02-01

    Generally, two processes are involved in leaching and dissolution; (1) chemical reactions and (2) mass transfer by diffusion. The chemical reaction controls the dissolution rates only during the early stage of exposure to groundwater. The exterior-field mass transfer may control the long-term dissolution rates from the waste solid in a geologic repository. Masstransfer analyses rely on detailed and careful application of the governing equations that describe the mechanistic processes of transport of material between and within phases. We develop analytical models to predict the radionuclide release rate into the groundwater with five different approaches: a measurement-based model, a diffusion model, a kinetics model, a diffusion-and-kinetics model, and a modified diffusion model. We also collected experimental leaching data for a partial validation of the radionuclide release model based on the mass transfer theory. Among various types of corrosions, pitting is the most significant because of its rapid growth. The failure time of the waste container, which also can be interpreted as the containment time, is a milestone of the performance of a repository. We develop analytical models to predict the pit growth rate on the container surface with three different approaches: an experimental method, a statistical method, and a mathematical method based on the diffusion theory. (Author)

  2. Marine biogeochemistry of radionuclides

    International Nuclear Information System (INIS)

    Fowler, S.W.

    1997-01-01

    Radionuclides entering the ocean from runoff, fallout, or deliberate release rapidly become involved in marine biogeochemical cycles. Sources, sinks and transport of radionuclides and analogue elements are discussed with emphasis placed on how these elements interact with marine organisms. Water, food and sediments are the source terms from which marine biota acquire radionuclides. Uptake from water occurs by surface adsorption, absorption across body surfaces, or a combination of both. Radionuclides ingested with food are either assimilated into tissue or excreted. The relative importance of the food and water pathway in uptake varies with the radionuclide and the conditions under which exposure occurs. Evidence suggests that, compared to the water and food pathways, bioavailability of sediment-bound radionuclides is low. Bioaccumulation processes are controlled by many environmental and intrinsic factors including exposure time, physical-chemical form of the radionuclide, salinity, temperature, competitive effects with other elements, organism size, physiology, life cycle and feeding habits. Once accumulated, radionuclides are transported actively by vertical and horizontal movements of organisms and passively by release of biogenic products, e.g., soluble excreta, feces, molts and eggs. Through feeding activities, particles containing radionuclides are ''packaged'' into larger aggregates which are redistributed upon release. Most radionuclides are not irreversibly bound to such particles but are remineralized as they sink and/or decompose. In the pelagic zones, sinking aggregates can further scavenge particle-reactive elements thus removing them from the surface layers and transporting them to depth. Evidence from both radiotracer experiments and in situ sediment trap studies is presented which illustrates the importance of biological scavenging in controlling the distribution of radionuclides in the water column. (author)

  3. Derived release limits for radionuclides in airborne and liquid effluents for the Whiteshell Nuclear Research Establishment and errata

    International Nuclear Information System (INIS)

    Lemire, A.E.

    1989-08-01

    Radionuclides released to the environment may cause external and internal radiation exposure to man via a number of potential pathways. The resulting radiation dose due to such releases from any operating facility must be kept below dose limits specified in the regulations issued by the Atomic Energy Control Board of Canada. At the Whiteshell Nuclear Research Establishment (WNRE), there is one primary source of liquid effluent to the Winnipeg River via the process water outfall. There are five sources of gaseous effluents: the WR-1 stack; the incinerator stack in the waste management area; the active laboratories building (including the hot cells); the Active-Liquid Waste Treatment Centre; and the compactor-baler in the Waste Management Area. This report presents the methodology and models used to calculate the maximum permissible release rates of radionuclides for each of these sources

  4. Radionuclide release and aerosol generation during core debris interactions with concrete

    International Nuclear Information System (INIS)

    Powers, D.A.

    1986-01-01

    During severe accidents at nuclear power plants, it is possible for the reactor fuel to melt and penetrate the reactor vessel. This can lead to vigorous interaction of core materials (UO 2 , ZrO 2 , Zr, and stainless steel) with structural concrete. Sparging of the molten core debris by gases (H 2 O and CO 2 ) liberated from the concrete can lead to rapid release of radionuclides from the core debris. A theoretical description of this release process has been developed and is called the VANESA model. The treatments in the VANESA model of the thermodynamics of radionuclide vaporization and the kinetic barriers to vaporization will be described. Predictions obtained from the model will be compared to the results of tests of core debris/concrete interactions

  5. Environmental risks due to radionuclide releases Environmental Risks Due To Radionuclide Releases From The Oil And Gas Industry

    International Nuclear Information System (INIS)

    Steinhausler, F.

    2005-01-01

    Full text : Exploration and transport in the oil- and gas industry result in the release of elevated levels of natural radioactivity into the environment. This has the following impact: Due to the large volumes of water needed during the extraction of gas and oil the resulting waste water can contain increased concentration of natural radionuclides, such as radium (Ra 226) and its decay products; At the oil/water interface waste water and sludge precipitate and form scalings, containing elevated levels of radium (Ra 226); At oil- and gas extraction sites tanks and equipment can be coated with long-lived radon (Rn 222) decay products; Along oil- and gas pipelines (e.g., at compressor stations) radon (Rn 222) decay products can be deposited internally on metal surfaces, such as valves. Typical U 238-series concentration values in production water range from 8 to 42 kBq/ m3, respectively in scale from 1 to 1 000 kBq/kg. In addition, oil- and gas extraction results in significant releases of natural radionuclides to the atmosphere (Rn 222) and to the water (Th 228, Ra 226, Rn 222, Pb 210, Po 210); for example, about 0.15 GBq/a of Rn 222 are released to the atmosphere per 106 m3 of oil extracted. The disposal of large amounts of contaminated wastes (scales, sludges) represents an environmental problem for the scrap metal industry (recycling of steel pipes containing scales) and the housing industry (use of sludge for landfill below a residential area). Using data from the oil- and gas industry in Latin America, Europe and the Asia-Pacific region, the various exposure pathways are reviewed. Furthermore, the current efforts in defining a suitable regulatory framework are discussed

  6. Fate of major radionuclides in the liquid wastes released to coastal waters

    International Nuclear Information System (INIS)

    Bhat, I.S.; Verma, P.C.; Iyer, R.S.; Chandramouli, S.

    1980-01-01

    131 I, 134 Cs, 137 Cs and 60 Co have been reported as the major radionuclides in the low level liquid wastes released to coastal waters from atomic power stations. Silt absorption and desorption of the radionuclides were investigated. The exchangeability of the silt absorbed radionuclides and its dependence on particle size were also studied. More than 80% instantaneous absorpt;.on of 60 Co by suspended silt and less than 5% exchangeability of absorbed 60 Co were observed. Biological uptake of the radionuclides by the marine organisms present in sea waters was studied to evaluate radiation exposure pathways. A few benthic and crustacean organisms wnich are consumed by coastal population as fresh sea food, were observed to concentrate the radionuclides to a greater extent than other organisms. (H.K.)

  7. Uncertainty estimates for predictions of the impact of breeder-reactor radionuclide releases

    International Nuclear Information System (INIS)

    Miller, C.W.; Little, C.A.

    1982-01-01

    This paper summarizes estimates, compiled in a larger report, of the uncertainty associated with models and parameters used to assess the impact on man radionuclide releases to the environment by breeder reactor facilities. These estimates indicate that, for many sites, generic models and representative parameter values may reasonably be used to calculate doses from annual average radionuclide releases when these calculated doses are on the order of one-tenth or less of a relevant dose limit. For short-term, accidental releases, the uncertainty in the dose calculations may be much larger than an order of magnitude. As a result, it may be necessary to incorporate site-specific information into the dose calculation under such circumstances. However, even using site-specific information, inherent natural variability within human receptors, and the uncertainties in the dose conversion factor will likely result in an overall uncertainty of greater than an order of magnitude for predictions of dose following short-term releases

  8. Microbial transformations of radionuclides released from nuclear fuel reprocessing plants

    International Nuclear Information System (INIS)

    Francis, A.J.

    2007-01-01

    Microorganisms can affect the stability and mobility of the actinides U, Pu, Cm, Am, Np, and the fission products Tc, I, Cs, Sr, released from nuclear fuel reprocessing plants. Under appropriate conditions, microorganisms can alter the chemical speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution and the bioavailability. Dissolution or immobilization of radionuclides is brought about by direct enzymatic action or indirect non-enzymatic action of microorganisms. Although the physical, chemical, and geochemical processes affecting dissolution, precipitation, and mobilization of radionuclides have been investigated, we have only limited information on the effects of microbial processes. The mechanisms of microbial transformations of the major and minor actinides and the fission products under aerobic and anaerobic conditions in the presence of electron donors and acceptors are reviewed. (author)

  9. Dose assessment on natural radiation, natural radionuclide, and artificial radionuclide released by Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Hosoda, Masahiro; Tokonami, Shinji; Furukawa, Masahide

    2012-01-01

    Various radionuclides are distributed in environmental materials such as soil, rock, and water. People are exposed every day to natural radiation. According to the UNSCEAR 2008 report, Sources of Ionizing Radiation, natural radiation sources are categorized as terrestrial gamma-rays, radon, cosmic rays and food. The effective dose from radon, thoron and its decay products is about 50% of all natural radiation exposure. Consciousness of the Japanese public toward radiation exposure has significantly increased since the start of the Fukushima Dai-ichi Nuclear Power Station accident. In this paper, the nationwide survey and dose estimation for terrestrial gamma-rays and radon are summarized. External dose from artificial radionuclides released by the Fukushima accident are also reported. (author)

  10. Health risks from radionuclides released into the Clinch River

    International Nuclear Information System (INIS)

    Thomas, B.A.; Hoffman, F.O.; Miller, L.F.

    1999-01-01

    The purpose of this work is to estimate off-site radiation doses and health risks (with uncertainties) associated with the release of radionuclides from the X-10 site. Following an initial screening analysis, the exposure pathways of interest included fish ingestion, drinking water ingestion, the ingestion of milk and meat, and external exposure from shoreline sediment. Four representative locations along the Clinch River, from the White Oak Creek Embayment to the city of Kingston, were chosen. The demography of the lower Clinch River supplied information dealing with land use that aided in the determination of sites on which to focus efforts. The locations that proved to be the most significant included Jones Island at Clinch River Mile (CRM) 20.5, Grassy Creek and K-25 (CRM 14), Kingston Steam Plant (CRM 3.5), and the city of Kingston (CRM 0). These areas of interest have historically been and are still primarily agricultural and residential areas. Reference individuals were determined with respect to the pathways involved. The primary radionuclides of interest released from the X-10 facility into the Clinch River via White Oak Creek were identified in the initial screening analysis as 137 Cs, 90 Sr, 60 Co, 106 Ru, 144 Ce, 131 I, 95 Zr, and 95 Nb. Of these radionuclides, 137 Cs, 60 Co, 106 Ru, 90 Sr, 144 Ce, 95 Zr, and 95 Nb were evaluated for their contribution to the external exposure pathway. This study utilized an object-oriented modeling software package that provides an alternative to the spreadsheet, providing graphical influence diagrams to show qualitative structure of models, hierarchical models to organize complicated models into manageable modules, and intelligent arrays with the power to scale up simple models to handle large problems. The doses and risks estimated in this study are not significant enough to cause a detectable increase in health effects in the population. In most cases, the organ does are well below the limits of epidemiological

  11. Impact assessment of radionuclides released to environment from the European Spallation Source

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S.; Andersson, K. [Technical University of Denmark (Denmark); Ene, D. [European Spallation Soure AB - ESS, Lund (Sweden)

    2014-07-01

    The European Spallation Source (ESS) is a large science and technology infrastructure project currently under construction in Lund, Sweden, with operation planned by 2019. The facility design and construction includes a linear proton accelerator, a heavy-metal target station, neutron instruments, laboratories, and a data management and software development centre. During operation the ESS will produce a wide range of radionuclides via spallation and activation processes. Radiological assessments are needed to ensure that operational discharges and releases from potential incidents/accidents are within acceptable limits. The spectrum of radionuclides produced at ESS is quite different from that produced in nuclear power plants and assessment work has therefore been challenged by lack of information on less well-known radionuclides. Traditional assessment methodologies have been applied focusing on releases to air and public sewer systems and calculating radiation doses to representative persons living in and near Lund close to the ESS site. Exposure pathways considered include external radiation from radionuclides in air, external radiation from radionuclides deposited on ground and skin, inhalation of radionuclides and ingestion of locally produced contaminated food. Atmospheric dispersion has been simulated with the Gaussian plume model which is considered adequate within a few kilometres. Effects of release height have been investigated and site specific values of other parameters such as wind speed, wind direction, rain fall etc. have been used. Contamination of food has been calculated from the (ECOSYS) food dose model used in the RODOS and ARGOS decision support systems. The food dose model does not contain specific data for a number of ESS relevant radionuclides, e.g. {sup 7}Be, {sup 32}P and {sup 35}S. The data required include mobility of these isotopes, soil-to-plant concentration ratios and equilibrium transfer factors of daily intake by ingestion of meat

  12. Radionuclide release from PWR fuels in a reference tuff repository groundwater

    International Nuclear Information System (INIS)

    Wilson, C.N.; Oversby, V.M.

    1985-03-01

    The Nevada Nuclear Waste Storage Investigations Project (NNWSI) is studying the suitability of the welded devitrified Topopah Spring tuff at Yucca Mountain, Nye County, Nevada, for potential use as a high-level nuclear waste repository. In support of the Waste Package task of NNWSI, tests have been conducted under ambient air environment to measure radionuclide release from two pressurized water reactor (PWR) spent fuels in water obtained from the J-13 well near the Yucca Mountain site. Four specimen types, representing a range of fuel physical conditions that may exist in a failed waste canister containing a limited amount of water were tested. The specimen types were: fuel rod sections split open to expose bare fuel particles; rod sections with water-tight end fittings with a 2.5-cm long by 150-μm wide slit through the cladding; rod sections with water-tight end fittings and two 200-μm-diameter holes through the cladding; and undefected rod segments with water-tight end fittings. Radionuclide release results from the first 223-day test runs on H.B. Robinson spent fuel specimens in J-13 water are reported and compared to results from a previous test series in which similar Turkey Point reactor spent fuel specimens were tested on deionized water. Selected initial results are also given for Turkey Point fuel specimens tested on J-13 water. Results suggest that the actinides Pu, Am, Cm and Np are released congruently with U as the UO 2 spent fuel matrix dissolves. Fractional release of 137 Cs and 99 Tc was greater than that measured for the actinides. Generally, lower radionuclide releases were measured for the H.B. Robinson fuel in J-13 water than for Turkey Point Fuel in deionized water. 8 references, 7 figures, 9 tables

  13. Integrated performance assessment model for waste package behavior and radionuclide release

    International Nuclear Information System (INIS)

    Kossik, R.; Miller, I.; Cunnane, M.

    1992-01-01

    Golder Associates Inc. (GAI) has developed a probabilistic total system performance assessment and strategy evaluation model (RIP) which can be applied in an iterative manner to evaluate repository site suitability and guide site characterization. This paper describes one component of the RIP software, the waste package behavior and radionuclide release model. The waste package component model considers waste package failure by various modes, matrix alteration/dissolution, and radionuclide mass transfer. Model parameters can be described as functions of local environmental conditions. The waste package component model is coupled to component models for far-field radionuclide transport and disruptive events. The model has recently been applied to the proposed repository at Yucca Mountain

  14. Nuclear decay data for radionuclides occurring in routine releases from nuclear fuel cycle facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D.C.

    1977-08-01

    This report gives tabulations of the atomic and nuclear radiations emitted by 240 radionuclides. Most of the radionuclides are those expected to occur in routine releases of effluents from nuclear fuel cycle facilities. For each radionuclide are given the half-life and recommended values for the energies, intensities, and equilibrium absorbed-dose constants for each of the atomic and nuclear radiations. Also given are the daughter radionuclides produced and recommended values for decay branching ratios, where applicable. The radioactivity decay chains and branching ratios are displayed in diagram form.

  15. Nuclear decay data for radionuclides occurring in routine releases from nuclear fuel cycle facilities

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1977-08-01

    This report gives tabulations of the atomic and nuclear radiations emitted by 240 radionuclides. Most of the radionuclides are those expected to occur in routine releases of effluents from nuclear fuel cycle facilities. For each radionuclide are given the half-life and recommended values for the energies, intensities, and equilibrium absorbed-dose constants for each of the atomic and nuclear radiations. Also given are the daughter radionuclides produced and recommended values for decay branching ratios, where applicable. The radioactivity decay chains and branching ratios are displayed in diagram form

  16. Principles for the limitation of releases of radionuclides from nuclear power plants to the atmosphere. A model of food chain system

    International Nuclear Information System (INIS)

    Pensko, J.; Stpiczynska, Z.

    1976-01-01

    On the basis of reference data the principles are set up for the limitation of releases of radioactive substances from nuclear power plants to the environment to maintain the radiation exposure of population to the level of accepted dose limits. The main attention is paid to the transfer of radionuclides released through food chain to man. For that purpose the mathematical model of population exposure by food chain which relates the radiation doses to the activity of radionuclides released is presented. The Laplace transformation is used to simplify the solution of the differential equations. It is shown that the estimation of the population exposure with the aid of a food chain mathematical model not only gives the permissible limits of release but also indicates the ways of proper radiological control program in the environment of nuclear installations. (author)

  17. Estimate of radionuclide release characteristics into containment under severe accident conditions

    International Nuclear Information System (INIS)

    Nourbakhsh, H.P.

    1993-11-01

    A detailed review of the available light water reactor source term information is presented as a technical basis for development of updated source terms into the containment under severe accident conditions. Simplified estimates of radionuclide release and transport characteristics are specified for each unique combination of the reactor coolant and containment system combinations. A quantitative uncertainty analysis in the release to the containment using NUREG-1150 methodology is also presented

  18. Radionuclides release to three rivers by ore treatment unit at Caldas, Minas Gerais - Brazil

    International Nuclear Information System (INIS)

    Pereira, W.S.; Carmo, R.F. do; Py Junior, D.A.

    2013-01-01

    The Ore Treatment Unit (OTU) is a uranium mining and milling plant, situated at Caldas city, Minas Gerais, Brazil that was disabled in the mid 90's. This unit releases controlled effluents to three rivers: Ribeirao das Antas (at point 014, influenced by the waste pile), Ribeirao Soberbo (point 025, influenced by the waste pond) and Corrego da Consulta (at point 076, influenced by the open pit mine). Water samples collected at these points were analyzed for U nat , 226 Ra, 210 Pb, 232 Th and 228 Ra content in the particulate and soluble fractions, and the behavior of radionuclide releases and their fractions was investigated. U nat and 228 Ra showed identical behaviors at these three points. U nat at point 014 (waste pile) behaved different from described in recent literature data. The isotopes of Ra should exhibit the same behavior at each point, but this was not observed at point 025 (waste pond). 232 Th release showed equal activity concentration near the waste pile (point 014) and near the waste pond (point 025), whilst near the open pit mine (point 076) the soluble fraction showed a concentration of activity greater than the particulate fraction. Finally, 210 Pb showed a different behavior at each point. Due to the great differences in behaviors of each radionuclide, it was not possible to establish a temporal pattern of release which requires assessment over a longer period of time. (author)

  19. Evaluation of Radionuclide Release from Aluminum-Based SNF in Basin Storage

    International Nuclear Information System (INIS)

    Sindelar, R.L.; Burke, S.D.; Howell, J.P.

    1998-09-01

    This report provides an evaluation of the release rates of radionuclides from breached A1-SNF assemblies and evaluates the effect of direct storage of breached fuel at a conservative upper bound reference condition on the SRS basin water activity levels

  20. HABIT, Toxic and Radioactive Release Hazards in Reactor Control Room

    International Nuclear Information System (INIS)

    Stage, S.A.

    2005-01-01

    1 - Description of program or function: HABIT is a package of computer codes designed to be used for the evaluation of control room habitability in the event of an accidental release of toxic chemicals or radioactive materials. 2 - Methods: Given information about the design of a nuclear power plant, a scenario for the release of toxic or radionuclides, and information about the air flows and protection systems of the control room, HABIT can be used to estimate the chemical exposure or radiological dose to control room personnel

  1. Radionuclides release from re-irradiated fuel under high temperature and pressure conditions. Gamma-ray measurements of VEGA-5 test

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, Akihide; Kudo, Tamotsu; Nakamura, Takehiko; Kanazawa, Toru; Kiuchi, Toshio; Uetsuka, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The VEGA (Verification Experiments of radionuclides Gas/Aerosol release) program is being performed at JAERI to clarify mechanisms of radionuclides release from irradiated fuel during severe accidents and to improve source term predictability. The fifth VEGA-5 test was conducted in January 2002 to confirm the reproducibility of decrease in cesium release under elevated pressure that was observed in the VEGA-2 test and to investigate the release behavior of short-life radionuclides. The PWR fuel of 47 GWd/tU after about 8.2 years of cooling was re-irradiated at Nuclear Safety Research Reactor (NSRR) for 8 hours before the heat-up test. After that, the two pellets of 10.9 g without cladding were heated up to about 2,900 K at 1.0 MPa under the inert He condition. The experiment reconfirmed the decrease in cesium release rate under the elevated pressure. The release data on short-life radionuclides such as Ru-103, Ba-140 and Xe-133 that have never been observed in the previous VEGA tests without re-irradiation was obtained using the {gamma} ray measurement. (author)

  2. Assessment of permissible low-level releases of radionuclides into the marine environment

    International Nuclear Information System (INIS)

    Kryshev, I.I.; Sazykina, T.G.

    2002-01-01

    The subject of this paper is radio-ecological assessment of permissible low-level releases of radionuclides in sea waters ensuring the radiological protection of the human population, as well as marine biota. (author)

  3. Modelling for radiological and radioecological consequences of an accidental radionuclide release at Sea

    International Nuclear Information System (INIS)

    Paschoa, A.S.

    1997-01-01

    Full text: Scenarios concerning accidental releases of radionuclides into water bodies can be found in the open literature, mostly in connection with nuclear power plants located either onshore or inland. However, meager attention has been given to nuclear reactors used as energy sources for propulsion at sea, which are also subject to accidents. Such potential accidents may involve the loss of part of the reactor core to the surrounding water body. In addition of the initial instantaneous releases, one can estimate delayed source terms based on the rate at which radionuclides are dissolved or leached from the solidified material, like part of the core or structural materials in contact with water. Most of such solidified material might be a mixture of uranium, zirconium, iron, calcium, silica, fission and activation products, and transuranium elements as oxides, forming a glassy type solid. Transport models were used to calculate radionuclide concentrations in water resulting from short and delayed source terms. Oceanographic data used in the calculations were taken either from the open literature or from unclassified reports of the Brazilian Navy, being, however, as generic as possible. Time-dependent concentration functions for radionuclides in aquatic food following an accidental release reflect the net result of intake and elimination processes. However, to avoid the complexities of multiple parameters involved in such processes, the model accounts only for trophic transfer of radionuclides, and yet avoids the necessity of analyzing the details of each transfer step used to determine fish, crustacea, molluscs and seaweed accumulation. Swimming and other aquatic sports are not included in the model used for dose calculations because of theirs relatively low importance in comparison with the pathways concerning ingestion of aquatic food

  4. Natural radionuclides in effluents release by a deactivated uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner S.; Kelecom, Alphonse; Silva, Ademir X.; Lopes, José M.; Pinto, Carlos E.C.; Py Júnior, Delcy A.; Antunes, Marcos M., E-mail: pereiraws@gmail.com, E-mail: caerjbr@gmail.com, E-mail: wspereira@inb.gov.br, E-mail: delcy@inb.gov.br, E-mail: Antunes@inb.gov.br, E-mail: lararapls@hotmail.com, E-mail: Ademir@nuclear.ufrj.br, E-mail: marqueslopes@yahoo.com.br [Universidade Veiga de Almeida (UVA), Rio de Janeiro, RJ (Brazil); Indústrias Nucleares do Brasil (COMAP.N/FCN/INB), Resende RJ (Brazil). Fábrica de Combustível Nuclear. Coordenação de Meio Ambiente e Proteção Radiológica Ambiental; Universidade Federal Fluminense (LARARA-PLS/UFF), Niterói, RJ (Brazil). Laboratório de Radiobiologia e Radiometria; Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-07-01

    The Ore Treatment Unit (OTU) is a mine and deactivated uranium plant in the city of Caldas, Minas Gerais, Brazil. This facility possesses three points of release of liquid effluents containing radionuclides: point 014, 025 and 076. At these points, the values of activity concentrations (AC) of the radionuclides U{sub nat}, {sup 226}Ra, {sup 210}Pb, {sup 232}Th and {sup 228}Ra were analyzed in 2012. The evaluation of point 014 by univariate statistics pointed four groups. [U{sub nat} > {sup 228}Ra > ({sup 226}Ra = {sup 210}Pb) >{sup 232}Th]. The multivariate statistics separated the radionuclides into two groups: [(U{sub nat} and {sup 232}Th) and ({sup 226}Ra, {sup 228}Ra and {sup 210}Pb)]. At point 025, the univariate statistics described three groups: [Un{sub at} > ({sup 228}Ra = {sup 210}Pb) > ({sup 226}Ra = {sup 232}Th)] and the multivariate analysis also described three but different groups: [(U{sub nat} and {sup 228}Ra), ({sup 226}Ra and {sup 210}Pb) and {sup 232}Th]. In turn, point 076 showed another behavior. The univariate analysis showed only two groups: [(U{sub nat}) > ({sup 226}Ra, {sup 228}Ra, {sup 210}Pb, {sup 232}Th)]. Differently, the multivariate statistics defined three groups: [(U{sub nat} and {sup 232}Th), ({sup 226}Ra and {sup 228}Ra) and {sup 210}Pb].Thus, statistical analysis showed that each point has releases of effluents with different characteristics. Both the behaviors of releases, based on multivariate statistics, and of the AC magnitudes, based on the univariate statistics, are different between the points. The only common features were the greater magnitude of uranium and the smaller magnitude of thorium. (author)

  5. Integrated performance assessment model for waste policy package behavior and radionuclide release

    International Nuclear Information System (INIS)

    Kossik, R.; Miller, I.; Cunnane, M.

    1992-01-01

    Golder Associates Inc. (GAI) has developed a probabilistic total system performance assessment and strategy evaluation model (RIP) which can be applied in an iterative manner to evaluate repository site suitability and guide site characterization. This paper describes one component of the RIP software, the waste package behavior and radionuclide release model. The waste package component model considers waste package failure by various modes, matrix alteration/dissolution, and radionuclide mass transfer. Model parameters can be described as functions of local environmental conditions. The waste package component model is coupled to component models for far-field radionuclide transport and disruptive events. The model has recently been applied to the proposed repository at Yucca Mountain

  6. Assessment of atmospherically-released radionuclides using the computerized radiological risk investigation system

    International Nuclear Information System (INIS)

    Nelson, C.B.; Sjoreen, A.L.; Miller, C.W.; Baes, C.F. III.

    1986-01-01

    For radionuclides, the standards are in terms of an annual dose, and the regulations require assurance that no member of the general public receives a dose in excess of that standard. Thus, spatial variations in the population around an emission source must be considered. Furthermore, for most chemical pollutants the standards are written in terms of an air concentration while for radionuclides other pathways of exposure, e.g., uptake of the airborne emissions by terrestrial food chains must also be considered. The remainder of this paper discusses the computer codes that make up the CRRIS and how they are used to perform an assessment of the health impacts on man of radionuclides released to the atmosphere

  7. Release criteria for patients having undergone radionuclide therapy and criteria for their crossing the state border of the Russian Federation

    International Nuclear Information System (INIS)

    Zvonova, I.; Balonov, M.; Golikov, V.

    2011-01-01

    By means of a conservative dosimetry model, the values of operational radiological criteria for patients released from hospital-residual activity in a body and dose rate near the patient's body-are substantiated based on the effective dose limit of 5 mSv for persons helping the patient or living with him and 1 mSv for other adults and children. Two sets of operative criteria for radionuclides 125 I, 131 I, 153 Sm and 188 Re used in Russia for radionuclide therapy were derived. Release criteria for 125 I well differ from such values in other countries because in this work absorption of 125 I low-energy photon radiation in the patient was taken into account. When a patient having undergone radionuclide therapy crosses the frontier of Russia, high-sensitivity devices for radiation control at the custom can detect the patient. A simplified radiological assessment of the patient was suggested aimed at provision of radiation safety for patient companions in transport. (authors)

  8. Radiological consequences of radionuclide releases to sewage systems from hospitals in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Rodolfo; Cruz, Idalmis de la [Facilia AB (Sweden); Bergman, Synnoeve [Vattenfall Power Consultants AB (Sweden); Hasselblad, Serena [Callido AB (Sweden)

    2007-08-15

    The report addresses radioactive discharges to sewers originating from hospitals, mainly in the form of the excretion of patients treated with radioisotopes for diagnostic or therapeutic purposes. Assessments of doses to the public, including sewage workers, arising from such discharges are performed. Doses are compared against the exemption level of 10 {mu}Sv/a and the dose constraint of 100 {mu}Sv/a. As a basis for the dose assessments, information on the use of radionuclides in Swedish hospitals during the period 1999-2004 is presented and estimates of discharges to the sewage systems are derived. Current sewage treatment practices in Sweden are summarised focusing particularly on the fate of sewage sludge, both in the sewage plant and outside. Radiological impact assessments are performed in two steps. The assessments in the first stage are performed using a simple screening model, not intending to predict exposures realistically but only to identify exposure pathways and radionuclides that are potentially relevant and require further consideration in the more detailed assessments. Results show that only a few of those radionuclides used in the period 1999-2004 in Swedish hospitals for radiotherapy and radiodiagnostics could lead to potentially significant doses (P-32, Y-90, Tc-99m, In-111, I-123, I-131 and Tl-201). Relevant exposure pathways are the external exposure of sewage workers (for Tc- 99m, I-123, I-131, In-111 and Tl-201) and the exposure of the public via ingestion of water (I-131) and fish (P-32, Y-90 and In-111 and I-131). The objective of the second stage is to perform realistic assessments of the doses to sewage workers and to the public through the use of contaminated agricultural sludge and through the contamination of drinking water. For this purpose, the LUCIA model was developed. This model dynamically addresses the behaviour of radionuclides in the different process steps of a sewage plant. The model can address continuous releases as well

  9. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Formulation of radionuclide release scenarios 2012

    International Nuclear Information System (INIS)

    2013-04-01

    TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR) and application for a construction licence for a repository for disposal of spent nuclear fuel at the Olkiluoto site in south-western Finland. This report presents the radionuclide release scenarios and the methodology followed in formulating them. The formulation of scenarios takes into account the regulatory framework, the knowledge acquired in the present safety case as well as in previous safety assessments, the safety functions of the barriers of the repository system and the uncertainties in the features, events, and processes (FEPs) that may affect the entire disposal system (i.e. repository system plus the surface environment) from the emplacement of the first canister until the far future. In the report Performance Assessment, the performance of the engineered and natural barriers has been assessed against the loads expected during the evolution of the repository system and the site. Uncertainties have been identified and these are taken into account in the formulation of radionuclide release scenarios. The uncertainties in the FEPs affecting the characteristics and evolution of the surface environment are taken into account in formulating the surface environment scenarios used ultimately for assessing radiation exposure. Formulating radionuclide release scenarios for the repository system links the reports Performance Assessment and Assessment of Radionuclide Release Scenarios for the Repository System. The formulation of radionuclide release scenarios for the surface environment brings together Biosphere Description and the surface environment FEPs and is the link to the assessment of the surface environment scenarios analysed in Biosphere Assessment. (orig.)

  10. Radionuclides release to three rivers by ore treatment unit at Caldas, Minas Gerais - Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W.S.; Carmo, R.F. do; Py Junior, D.A., E-mail: pereiraws@gmail.com [Industrias Nucleares do Brasil (INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerio. Grupo Multidisciplinar de Radioprotecao; Kelecom, A., E-mail: akelecom@id.uff.br [Universidade Federal Fluminense (LARARA-PLS/GETA/UFF), Niteroi, RJ (Brazil). Laboratorio de Radiobiologia e Radiometria Pedro Lopes dos Santos. Grupo de Estudos em Temas Ambientais; Pereira, J.R.S., E-mail: pereirarsj@gmail.com [Universidade Federal de Alfenas (UNIFAL), Pocos de Caldas, MG (Brazil)

    2013-07-01

    The Ore Treatment Unit (OTU) is a uranium mining and milling plant, situated at Caldas city, Minas Gerais, Brazil that was disabled in the mid 90's. This unit releases controlled effluents to three rivers: Ribeirao das Antas (at point 014, influenced by the waste pile), Ribeirao Soberbo (point 025, influenced by the waste pond) and Corrego da Consulta (at point 076, influenced by the open pit mine). Water samples collected at these points were analyzed for U{sub nat}, {sup 226}Ra, {sup 210}Pb, {sup 232}Th and {sup 228}Ra content in the particulate and soluble fractions, and the behavior of radionuclide releases and their fractions was investigated. U{sub nat} and {sup 228}Ra showed identical behaviors at these three points. U{sub nat} at point 014 (waste pile) behaved different from described in recent literature data. The isotopes of Ra should exhibit the same behavior at each point, but this was not observed at point 025 (waste pond). {sup 232}Th release showed equal activity concentration near the waste pile (point 014) and near the waste pond (point 025), whilst near the open pit mine (point 076) the soluble fraction showed a concentration of activity greater than the particulate fraction. Finally, {sup 210}Pb showed a different behavior at each point. Due to the great differences in behaviors of each radionuclide, it was not possible to establish a temporal pattern of release which requires assessment over a longer period of time. (author)

  11. Development of computer model for radionuclide released from shallow-land disposal facility

    International Nuclear Information System (INIS)

    Suganda, D.; Sucipta; Sastrowardoyo, P.B.; Eriendi

    1998-01-01

    Development of 1-dimensional computer model for radionuclide release from shallow land disposal facility (SLDF) has been done. This computer model is used for the SLDF facility at PPTA Serpong. The SLDF facility is above 1.8 metres from groundwater and 150 metres from Cisalak river. Numerical method by implicit method of finite difference solution is chosen to predict the migration of radionuclide with any concentration.The migration starts vertically from the bottom of SLDF until the groundwater layer, then horizontally in the groundwater until the critical population group. Radionuclide Cs-137 is chosen as a sample to know its migration. The result of the assessment shows that the SLDF facility at PPTA Serpong has the high safety criteria. (author)

  12. Review of radionuclides released from the nuclear fuel cycle and methods of assessing dose to man

    International Nuclear Information System (INIS)

    Bryant, P.M.

    1979-01-01

    There are two broad subject areas associated with releases of radionuclides from nuclear fuel cycle installations to the environment in which there are biological implications. One concerns interpretation of doses to man in terms of their radiological significance; the other concerns estimation of environmental transfer of radionuclides and of associated radiation doses to man. The radiation protection philosophy on which past practice regarding effluent releases of radionuclides to the environment was based is illustrated by drawing upon estimates of the associated radiation doses to man given in the 1977 report of the United Nations Scientific Committee on the Effects of Atomic Radiation. The present emphasis in radiation protection philosophy is illustrated by summarizing a review of environmental models relevant to estimation of radiation doses to population groups with reference to effluent releases of 3 H, 14 C, 85 Kr and 129 I; the author carried out the review as a contribution to a current study by an expert group set up by the Nuclear Energy Agency of OECD. Radionuclides of significance in the future may differ from those currently released to the environment because of possible developments in nuclear fuel cycles and options which may be exercised for disposal of high-level radioactive wastes, already in storage or postulated to be produced in the future. (author)

  13. Effects of building structures on radiation doses from routine releases of radionuclides to the atmosphere

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1978-01-01

    Realistic assessments of radiation doses to the population from routine releases of radionuclides to the atmosphere require consideration of man's largely indoor environment. The effect of a building structure on radiation doses is described quantitatively by a dose reduction factor, which is the ratio of the dose to a reference individual inside a structure to the corresponding dose with no structure present. We have implemented models to estimate dose reduction factors for internal dose from inhaled radionuclides and for external photon dose from airborne and surface-deposited radionuclides. The models are particularly useful in radiological assessment applications, since dose reduction factors may readily be estimated for arbitrary mixtures and concentrations of radionuclides in the atmosphere and on the ground. The model for inhalation dose reduction factors accounts for radioactive decay, air ventilation into and out of the structure, and deposition of radionuclides on inside surfaces of the structure. External dose reduction factors are estimated using the point-kernel integration method including consideration of buildup in air and the walls of the building. The potential importance of deposition of radionuclides on inside surfaces of a structure on both inhalation and external dose reduction factors has been demonstrated. Model formulation and the assumptions used in the calculations are discussed. Results of model-parameter sensitivity studies and estimates of dose reduction factors for radionuclides occurring in routine releases from an LWR fuel reprocessing plant are presented. (author)

  14. Radionuclide deposition control

    International Nuclear Information System (INIS)

    1980-01-01

    A method is described for controlling the deposition, on to the surfaces of reactor components, of the radionuclides manganese-54, cobalt-58 and cobalt-60 from a liquid stream containing the radionuclides. The method consists of disposing a getter material (nickel) in the liquid stream, and a non-getter material (tantalum, tungsten or molybdenum) as a coating on the surfaces where deposition is not desired. The process is described with special reference to its use in the coolant circuit in sodium cooled fast breeder reactors. (U.K.)

  15. A comparison of measured radionuclide release rates from Three Mile Island Unit-2 core debris for different oxygen chemical potentials

    International Nuclear Information System (INIS)

    Baston, V.F.; Hofstetter, K.J.; Ryan, R.F.

    1987-01-01

    Chemical and radiochemical analyses of reactor coolant samples taken during defueling of the Three Mile Island Unit-2 (TMI-2) reactor provide relevant data to assist in understanding the solution chemistry of the radionuclides retained within the TMI-2 reactor coolant system. Hydrogen peroxide was added to various plant systems to provide disinfection for microbial contamination and has provided the opportunity to observe radionuclide release under different oxygen chemical potentials. A comparison of the radionuclide release rates with and without hydrogen peroxide has been made for these separate but related cases, i.e., the fuel transfer canal and connecting spent-fuel pool A with the TMI-2 reactor plenum in the fuel transfer canal, core debris grab sample laboratory experiments, and the reactor vessel fluid and associated core debris. Correlation and comparison of these data indicate a physical parameter dependence (surface-to-volume ratio) affecting all radionuclide release; however, selected radionuclides also demonstrate a chemical dependence release under the different oxygen chemical potentials. Chemical and radiochemical analyses of reactor coolant samples taken during defueling of the Three Mile Island Unit-2 (TMI-2) reactor provide relevant data to assist in understanding the solution chemistry of the radionuclides retained within the TMI-2 reactor coolant system

  16. Ecological reconcentrations of radionuclides released by nuclear industry

    International Nuclear Information System (INIS)

    Schaeffer, R.

    1977-01-01

    An attempt is made to assess the relative importance of the various pathways to man by relating the doses that in the most unfavorable conditions might result from long-term environmental accumulation of the radionuclides to the doses resulting from air inhalation or water ingestion only. For instance, for 131 I released in air, the ratio may reach a value of 1,000 from milk consumption and 3 from consumption of leafy vegetables. For 137 Cs released in water, the ratio may reach a value of 20 from the food chain contamination and 500 on account of external exposure from sediments. However, in spite of these high ratios, the absolute values of the total doses received remain low since the exposures corresponding to air inhalation or water ingestion are usually unsignificant. For water releases, attention is called on the misinterpretations that might result from generalizing the concentration factor values reported in the literature on account of their variations both in time and space: this factor ought to be calculated for each point of the environment on the basis of hydrological data [fr

  17. Natural radionuclides in effluents release by a deactivated uranium mine

    International Nuclear Information System (INIS)

    Pereira, Wagner S.; Kelecom, Alphonse; Silva, Ademir X.; Lopes, José M.; Pinto, Carlos E.C.; Py Júnior, Delcy A.; Antunes, Marcos M.; Indústrias Nucleares do Brasil; Universidade Federal Fluminense; Coordenacao de Pos-Graduacao e Pesquisa de Engenharia

    2017-01-01

    The Ore Treatment Unit (OTU) is a mine and deactivated uranium plant in the city of Caldas, Minas Gerais, Brazil. This facility possesses three points of release of liquid effluents containing radionuclides: point 014, 025 and 076. At these points, the values of activity concentrations (AC) of the radionuclides U_n_a_t, "2"2"6Ra, "2"1"0Pb, "2"3"2Th and "2"2"8Ra were analyzed in 2012. The evaluation of point 014 by univariate statistics pointed four groups. [U_n_a_t > "2"2"8Ra > ("2"2"6Ra = "2"1"0Pb) >"2"3"2Th]. The multivariate statistics separated the radionuclides into two groups: [(U_n_a_t and "2"3"2Th) and ("2"2"6Ra, "2"2"8Ra and "2"1"0Pb)]. At point 025, the univariate statistics described three groups: [Un_a_t > ("2"2"8Ra = "2"1"0Pb) > ("2"2"6Ra = "2"3"2Th)] and the multivariate analysis also described three but different groups: [(U_n_a_t and "2"2"8Ra), ("2"2"6Ra and "2"1"0Pb) and "2"3"2Th]. In turn, point 076 showed another behavior. The univariate analysis showed only two groups: [(U_n_a_t) > ("2"2"6Ra, "2"2"8Ra, "2"1"0Pb, "2"3"2Th)]. Differently, the multivariate statistics defined three groups: [(U_n_a_t and "2"3"2Th), ("2"2"6Ra and "2"2"8Ra) and "2"1"0Pb].Thus, statistical analysis showed that each point has releases of effluents with different characteristics. Both the behaviors of releases, based on multivariate statistics, and of the AC magnitudes, based on the univariate statistics, are different between the points. The only common features were the greater magnitude of uranium and the smaller magnitude of thorium. (author)

  18. Proceedings of the workshop on radionuclide release scenarios for geologic repositories

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The safety of radioactive waste disposal in geological formations cannot be verified experimentally. Safety analysis provides the only means to ensure that all risks associated with the waste repositories are acceptably low. The definition of radionuclide release scenarios, as discussed in these proceeedings, is the first step in the safety analysis of waste repositories.

  19. Important processes affecting the release and migration of radionuclides from a deep geological repository

    International Nuclear Information System (INIS)

    Barátová, Dana; Nečas, Vladimír

    2017-01-01

    The processes that affect significantly the transport of contaminants through the near field and far field of a deep geological repository of spent nuclear fuel were studied. The processes can be generally divided into (i) processes related to the release of radionuclides from the spent nuclear fuel; (ii) processes related to the radionuclide transport mechanisms (such as advection and diffusion); and (iii) processes affecting the rate of radionuclide migration through the multi-barrier repository system. A near-field and geosphere model of an unspecified geological repository sited in a crystalline rock is also described. Focus of the treatment is on the effects of the different processes on the activity flow of the major safety-relevant radionuclides. The activity flow was simulated for one spent fuel cask by using the GoldSim simulation tool. (orig.)

  20. Internal exposure of populations to long-lived radionuclides released into the environment

    International Nuclear Information System (INIS)

    Balonov, M.I.

    1997-01-01

    This chapter discusses the events that led to the contamination of environments with the long-lived radionuclides of caesium, strontium and other elements, and to the internal exposure of populations living in contaminated areas. Among these events are radioactive releases into the river Techa from the Soviet nuclear weapons facility Mayak in 1949-1956, thermonuclear weapons test in the 1950s and 1960s, the Kyshtim and Windscale accidents in 1957, and the Chernobyl and Tomsk-7 accidents in 1986 and 1993, respectively. Methods of environmental monitoring and individual internal dose monitoring of inhabitants are described. These are based on measuring the content of radionuclides not only in the air, drinking water and local food products, but also in humans using whole-body counters and analysing excreta and autopsy samples. The dynamics of internal exposure of people of different ages to radionuclides of caesium, strontium and plutonium from the environment are considered. Examples of radionuclide distributions in the environment, and of individual/collective internal doses and related medical effects are presented. (Author)

  1. Model to estimate radiation dose commitments to the world population from the atmospheric release of radionuclides (LWBR development program)

    International Nuclear Information System (INIS)

    Rider, J.L.; Beal, S.K.

    1978-02-01

    The equations developed for use in the LWBR environmental statement to estimate the dose commitment over a given time interval to a given organ of the population in the entire region affected by the atmospheric releases of a radionuclide are presented and may be used for any assessment of dose commitments in these regions. These equations define the dose commitments to the world resulting from a released radionuclide and each of its daughters and the sum of these dose commitments provides the total dose commitment accrued from the release of a given radionuclide. If more than one radionuclide is released from a facility, then the sum of the dose commitments from each released nuclide and from each daughter of each released nuclide is the total dose commitment to the world from that facility. Furthermore, if more than one facility is considered as part of an industry, then the sum of the dose commitments from the individual facilities represents the total world dose commitment associated with that industry. The actual solutions to these equations are carried out by the AIRWAY computer program. The writing of this computer program entailed defining in detail the specific representations of the various parameters such as scavenging coefficients, resuspension factors, deposition velocities, dose commitment conversion factors, and food uptake factors, in addition to providing specific numerical values for these types of parameters. The program permits the examination of more than one released nuclide at a time and performs the necessary summing to obtain the total dose commitment to the world accrued from the specified releases

  2. Dose evaluation model for radionuclides released from the spent nuclear fuel reprocessing plant in Rokkasho

    International Nuclear Information System (INIS)

    Hisamatsu, Shun'ichi; Iyogi, Takashi; Inaba, Jiro; Chiang, Jing-Hsien; Suwa, Hiroji; Koide, Mitsuo

    2007-01-01

    A dose evaluation model was developed for radionuclides released from the spent nuclear fuel reprocessing plant which is located in Rokkasho, Aomori Prefecture, and now undergoing test operation. The dose evaluation model suitable for medium- and long-term dose assessments for both prolonged and short-term releases of radionuclides to the atmosphere was developed on the PC. The ARAC-2, a particle tracing type dispersion model coupled with 3-D wind field calculation by a mass conservative model, was adopted as the atmospheric dispersion model. The terrestrial transfer model included movement in soil and groundwater as well as an agricultural and livestock farming system. The available site-specific social and environmental characteristics were incorporated in the model. Growing of the crops was also introduced and radionuclides absorbed were calculated from weight increase from the start of deposition to harvest, and transfer factors. Most of the computer code system of the models was completed by 2005, and this paper reports the results of the development. (author)

  3. Release of radionuclides following severe accident in interim storage facility. Source term determination

    International Nuclear Information System (INIS)

    Morandi, S.; Mariani, M.; Giacobbo, F.; Covini, R.

    2006-01-01

    Among the severe accidents that can cause the release of radionuclides from an interim storage facility, with a consequent relevant radiological impact on the population, there is the impact of an aircraft on the facility. In this work, a safety assessment analysis for the case of an aircraft crash into an interim storage facility is tackled. To this aim a methodology, based upon DOE, IAEA and NUREG standard procedures and upon conservative yet realistic hypothesis, has been developed in order to evaluate the total radioactivity, source term, released to the biosphere in consequence of the impact, without recurring to the use of complicated numerical codes. The procedure consists in the identification of the accidental scenarios, in the evaluation of the consequent damage to the building structures and to the waste packages and in the determination of the total release of radionuclides through the building-atmosphere interface. The methodology here developed has been applied to the case of an aircraft crash into an interim storage facility currently under design. Results show that in case of perforation followed by a fire incident the total released activity would be greater of some orders of magnitude with respect to the case of mere perforation. (author)

  4. Modeling of release of radionuclides from an engineered disposal facility for shallow-land disposal of low-level radioactive wastes

    International Nuclear Information System (INIS)

    Matsuzuru, H.; Suzuki, A.

    1989-01-01

    The computer code, ENBAR-1, for the simulation of radionuclide releases from an engineered disposal facility has been developed to evaluate the source term for subsequent migration of radionuclides in and through a natural barrier. The system considered here is that a waste package (waste form and container) is placed, together with backfill materials, into a concrete pit as a disposal unit for shallow-land disposal of low-level radioactive wastes. The code developed includes the following modules: water penetration into a concrete pit, corrosion of a drum as a container, leaching of radionuclides from a waste form, migration of radionuclides in backfill materials, release of radionuclides from the pit. The code has the advantage of its simplicity of operation and presentation while still allowing comprehensive evaluation of each element of an engineered disposal facility to be treated. The performance and source term of the facility might be readily estimated with a few key parameters to define the problem

  5. ASSESSMENT OF RELEASE RATES FOR RADIONUCLIDES IN ACTIVATED CONCRETE.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN,T.M.

    2003-08-23

    The Maine Yankee (MY) nuclear power plant is undergoing the process of decontamination and decommissioning (D&D). Part of the process requires analyses that demonstrate that any radioactivity that remains after D&D will not cause exposure to radioactive contaminants to exceed acceptable limits. This requires knowledge of the distribution of radionuclides in the remaining material and their potential release mechanisms from the material to the contacting groundwater. In this study the concern involves radionuclide contamination in activated concrete in the ICI Sump below the containment building. Figures 1-3 are schematic representations of the ICI Sump. Figure 2 and 3 contain the relevant dimensions needed for the analysis. The key features of Figures 2 and 3 are the 3/8-inch carbon steel liner that isolates the activated concrete from the pit and the concrete wall, which is between 7 feet and 7 feet 2 inches thick. During operations, a small neutron flux from the reactor activated the carbon steel liner and the concrete outside the liner. Current MY plans call for filling the ICI sump with compacted sand.

  6. The impacts of radionuclide releases into the marine environment

    International Nuclear Information System (INIS)

    1981-01-01

    The impact of radiation on the marine environment has been of interest to the international community since the advent of nuclear fission. This interest continues with the increasing industrial use of nuclear power and the associated need for the disposal of nuclear waste. Continued dumping of low-level waste into the sea and direct discharge of liquid effluents into coastal waters, as well as potential radionuclide additions to the deep ocean from other sources, dictates that the possible long-term effects on the seas must be closely watched. By means of field studies in contaminated environments, our knowledge of long-lived radionuclides, especially the transuranium elements, is increasing. We are far from the goal, however, of being able to predict the behaviour of these elements in the marine environment, particularly in the deep sea. We know even less about other long-lived radionuclides such as technetium, whose inventory may be as high as 170 000 kg by the year 2000 according to some projections. Clearly, attempts to unravel the behaviour and fate of these long-lived radionuclides introduced into the sea will present a challenge to the environmental scientist during the next decade. In addition, the new philosophy of the International Commission on Radiological Protection (ICRP) as set out in Publication No.26, emphasizes justification and optimization both in the release of radioactive effluents into the sea and in the sea-dumping of radioactive solid wastes. To satisfy the demands of this new philosophy requires a broader range of environmental information than has previously been available. The papers assembled for this symposium represent an authoritative account of the subject's global status in 1980. The object of the meeting was to review the origins, measurements, behaviour, fate and impacts of artificial radioactive additions to the marine environment

  7. 21 CFR 892.5700 - Remote controlled radionuclide applicator system.

    Science.gov (United States)

    2010-04-01

    ... radionuclide applicator system. (a) Identification. A remote controlled radionuclide applicator system is an... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Remote controlled radionuclide applicator system... include patient and equipment supports, component parts, treatment planning computer programs, and...

  8. TURVA-2012: Assessment of radionuclide release scenarios for the repository system

    International Nuclear Information System (INIS)

    Smith, Paul; Poteri, Antti; Nordman, Henrik; Cormenzana, Jose Luis; Snellman, Margit; Marcos, Nuria; Hjerpe, Thomas; Koskinen, Lasse

    2014-01-01

    TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR) and application for a construction licence for a repository for disposal of spent nuclear fuel at the Olkiluoto site in south-western Finland. This paper gives a summary of the analyses of the radionuclide release scenarios formulated in a companion paper, TURVA-2012: Formulation of Radionuclide Release Scenarios (Marcos, 2014). The scenarios and the analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in a further paper: TURVA-2012: Performance Assessment (Hellae, 2014). For each scenario, calculation cases are analysed to evaluate compliance of the proposed repository with regulatory requirements on radiological protection, as well as to illustrate the impact of specific uncertainties or combinations of uncertainties on the calculated results. Each case illustrates different possibilities for how the repository might evolve and perform over time, taking into account uncertainties in the models and parameter values used to represent radionuclide release, retention and transport and, for biosphere assessment calculation cases, radiation exposure. The calculation cases each address a single, failed canister, where three possible modes of failure are considered: - The presence of an initial defect in the copper overpack of the canister that penetrates the overpack completely (subsequent corrosion of the insert may then lead to an enlargement of the defect). - Corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion. - Shear movements on fractures intersecting the deposition holes. However, the likelihood and consequences of more than one canister failure occurring during the assessment time fame are also considered, generally based on the findings from the single canister calculations. Quantitative

  9. Comparison of US/FRG accident condition models for HTGR fuel failure and radionuclide release

    International Nuclear Information System (INIS)

    Verfondern, K.

    1991-03-01

    The objective was to compare calculation models used in safety analyses in the US and FRG which describe fission product release behavior from TRISO coated fuel particles under core heatup accident conditions. The frist step performed is the qualitative comparison of both sides' fuel failure and release models in order to identify differences and similarities in modeling assumptions and inputs. Assumptions of possible particle failure mechanisms under accident conditions (SiC degradation, pressure vessel) are principally the same on both sides though they are used in different modeling approaches. The characterization of a standard (= intact) coated particle to be of non-releasing (GA) or possibly releasing (KFA/ISF) type is one of the major qualitative differences. Similar models are used regarding radionuclide release from exposed particle kernels. In a second step, a quantitative comparison of the calculation models was made by assessing a benchmark problem predicting particle failure and radionuclide release under MHTGR conduction cooldown accident conditions. Calculations with each side's reference method have come to almost the same failure fractions after 250 hours for the core region with maximum core heatup temperature despite the different modeling approaches of SORS and PANAMA-I. The comparison of the results of particle failure obtained with the Integrated Failure and Release Model for Standard Particles and its revision provides a 'verification' of these models in this sense that the codes (SORS and PANAMA-II, and -III, respectively) which were independently developed lead to very good agreement in the predictions. (orig./HP) [de

  10. Individual radiation doses from unit releases of long lived radionuclides

    International Nuclear Information System (INIS)

    Bergstroem, U.; Nordlinder, S.

    1990-04-01

    The turn-over in a standard biosphere of radionuclides, disposed in a repository for high level waste was studied from a dose point of view. A multi-compartment model with unit releases to the biosphere was designed and solved by the BIOPATH-code. The uncertainty in the results due to the uncertainty in input parameter values were examined for all nuclides with the PRISM-system. Adults and five year old children were exposed from 10 different exposure pathways originating from activity in well and lake water. The results given as total doses per year and Bq release (conversion factors) can be used in combination with leakage rates from the geosphere for safety analysis of a repository. The conversion factors obtained (arithmetic mean values), are given. (65 refs.) (authors)

  11. [Ranking of radionuclides and pathways according to their contribution to the dose burden to the population resulting from NPP releases].

    Science.gov (United States)

    Spiridonov, S I; Karpenko, E I; Sharpan, L A

    2013-01-01

    Approaches are described towards estimating the consequences of radioactive contamination of ecosystems by nuclear fuel cycle enterprises with the rationale for the optimal specification level for nuclear power plants (NPP) operating in the normal mode. Calculations are made based on the initial data of the IAEA project, INPRO ENV, dealing with the ranking of radionuclides escaping to the environment from the operating NPPs. Influence of various factors on rankings of radionuclides and pathways of public exposure is demon- strated. An important factor is the controlled radionuclide composition of atmospheric NPP releases. It has been found that variation in the dose coefficients for some radionuclides leads to significant changes not only in the ranking results but also in the estimates of total dose burdens. Invariability is shown of the estimation concerning the greatest contribution of the peroral route to the population dose of irradiation in the situation considered. A conclusion was drawn on the need of taking into consideration uncertainties of different factors when comparing effects on the environment from enterprises of conventional and innovative nuclear fuel cycles.

  12. Atmospheric dispersion of radionuclides released by a nuclear plant

    International Nuclear Information System (INIS)

    Barboza, A.A.

    1989-01-01

    A numerical model has been developed to simulate the atmospheric dispersion of radionuclides released by a nuclear plant operating under normal conditions. The model, based on gaussian plume representation, accouts for and evaluates several factors which affect the concentraction of effluents in the atmosphere, such as: ressuspension, deposition, radioactive decay, energy and type of the radiation emitted, among others. The concentraction of effluents in the atmosphere is calculated for a uniform mesh of points around the plant, allowing the equivalent doses to be then evaluated. Simulations of the atmosphere dispersion of radioactive plumes of Cs 137 and Ar 41 have been performed assuming a constant rate of release, as expected from the normal operation of a nuclear plant. Finally, this work analyzes the equivalent doses at ground level due to the dispersion of Cs 137 and Ar 41 , accumulated over one year and determines the isodose curves for a hypothetical site. (author) [pt

  13. Application of two-barrier model of radioactive agent transport in sea water for analyzing artificial radionuclide release from containers with radioactive waste dumped in Kara Sea

    Energy Technology Data Exchange (ETDEWEB)

    Grishin, Denis S.; Laykin, Andrey I.; Kuchin, Nickolay L.; Platovskikh, Yuri A. [Krylov State Research Center, Saint Petersburg, 44 Moskovskoe shosse, 196158 (Russian Federation)

    2014-07-01

    Modeling of artificial radionuclide transport in sea water is crucial for prognosis of radioecological situation in regions where dumping of radioactive waste had been made and/or accidents with nuclear submarines had taken place. Distribution of artificial radionuclides in bottom sediments can be a detector of radionuclide release from dumped or sunk objects to marine environment. Proper model can determine the dependence between radionuclide distribution in sediments and radionuclide release. Following report describes two-barrier model of radioactive agent transport in sea water. It was tested on data from 1994 - 2013 expeditions to Novaya Zemlya bays, where regular dumping of solid radioactive waste was practiced by the former USSR from the early 1960's until 1990. Two-barrier model agrees with experimental data and allows more accurate determination of time and intensity of artificial radionuclide release from dumped containers. (authors)

  14. Probability of liquid radionuclide release of a near surface repository; Probabilidade de liberacao liquida de radionuclideos de um repositorio proximo a superficie

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Lais A.; Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: lais@con.ufrj.br; frutuoso@con.ufrj.br; Passos, Erivaldo; Alves, Antonio Sergio [ELETRONUCLEAR, Rio de Janeiro, RJ (Brazil). Div. de Seguranca Nuclear]. E-mail: epassos@eletronuclear.gov.br; asergi@eletronuclear.gov.br

    2005-07-01

    The safety analysis of a near surface repository for medium and low activity wastes leads to investigating accident scenarios related to water infiltration phenomena. The probability of radionuclide release through the infiltration water could be estimated with the aid of suitable probabilistic models. For the analysis, the repository system is divided into two subsystems: the first, due to the barriers against the water infiltration (backfill material and container), and the second one comprising the barriers against the leaching of radionuclide to the biosphere (solid matrix and geosphere). The repository system is supposed to have its components (barriers) working in an active parallel mode. The probability of the system failure is obtained from the logical structure of a failure tree. The study was based on the Probabilistic Safety Assessment (PSA) technique for the most significant radionuclides within the radioactive packages system of low and medium activity, and so the probability of failure of the system for each radionuclide during the time period of institutional control was obtained. (author)

  15. Conditions inside Water Pooled in a Failed Nuclear Waste Container and its Effect on Radionuclide Release

    Science.gov (United States)

    Hamdan, L. K.; Walton, J. C.; Woocay, A.

    2009-12-01

    Nuclear power use is expected to expand in the future, as part of the global clean energy initiative, to meet the world’s surging energy demand, and attenuate greenhouse gas emissions, which are mainly caused by fossil fuels. As a result, it is estimated that hundreds of thousands of metric tons of spent nuclear fuel (SNF) will accumulate. SNF disposal has major environmental (radiation exposure) and security (nuclear proliferation) concerns. Storage in unsaturated zone geological repositories is a reasonable solution for dealing with SNF. One of the key factors that determine the performance of the geological repository is the release of radionuclides from the engineered barrier system. Over time, the nuclear waste containers are expected to fail gradually due to general and localized corrosions and eventually infiltrating water will have access to the nuclear waste. Once radionuclides are released, they will be transported by water, and make their way to the accessible environment. Physical and chemical disturbances in the environment over the container will lead to different corrosion rates, causing different times and locations of penetration. One possible scenario for waste packages failure is the bathtub model, where penetrations occur on the top of the waste package and water pools inside it. In this paper the bathtub-type failed waste container is considered. We shed some light on chemical and physical processes that take place in the pooled water inside a partially failed waste container (bathtub category), and the effects of these processes on radionuclide release. Our study considers two possibilities: temperature stratification of the pooled water versus mixing process. Our calculations show that temperature stratification of the pooled water is expected when the waste package is half (or less) filled with water. On the other hand, when the waste package is fully filled (or above half) there will be mixing in the upper part of water. The effect of

  16. Effluent release limits, sources and control

    International Nuclear Information System (INIS)

    Swindell, G.E.

    1977-01-01

    Objectives of radiation protection in relation to releases. Environmental transfer models for radionuclides. Relationship between releases, environmental levels and doses to persons. Establishment of release limits: Limits based on critical population group concept critical pathway analysis and identification of critical group. Limits based on optimization of radiation protection individual dose limits, collective doses and dose commitments 1) differential cost benefit analysis 2) authorized and operational limits taking account of future exposures. Monitoring of releases to the environment: Objectives of effluent monitoring. Typical sources and composition of effluents; design and operation of monitoring programmes; recording and reporting of monitoring results; complementary environmental monitoring. (orig.) [de

  17. Design of environment monitoring system to evaluate radionuclide release from subsystem on PWR nuclear power accident

    International Nuclear Information System (INIS)

    Sri Kuntjoro; Sugiyanto; Pande Made Udiyani; Jupiter Sitorus Pane

    2012-01-01

    Nuclear Power Plan (NPP) as a renewable energy source is selected as an alternative, because it has many advantages that is environmentally friendly, fuel supply which is independent of the season, and the price that can compete with other power plants. However, the existence of some public skepticism about nuclear radiation safety, the government must be convinced about the operation of nuclear power plants are safe and secure. Research on the design of environment monitoring system for evaluation of radionuclide release from the reactor subsystems and the environment due to accidents at power reactors has been done. The study was conducted by calculating the distribution of radionuclide release into the reactor subsystem and the environment and also to build the environment radiation monitoring system. Environmental monitoring system consists of a radiation counter, early warning systems, meteorological measurement systems, GPS systems and GIS. Radiation monitoring system used to record the data of radiation, meteorological measurement system used to record data of wind and speed direction, while the GPS system is used to determine position of data measurements. The data is then transmitted to a data acquisition system and then to be transmitted to the control center. Collection and transmission of data is done via SMS formatting using a modem device that is placed in the control center. The control center receives measurement data from various places. In this case the control center has a function as an SMS Gateway. This system can visualize for different measurement locations. Furthermore, radiation data and position data to be integrated with digital maps. System integration is then visualized in a personal computer. To position of measurements directly visualized on the map and also look for the data displayed on a monitor as a red or green circle colour. That colour indicated as a safe limit of radiation monitor. When the cycle colour is red, the system will

  18. Estimates of radionuclide release from glass waste forms in a tuff repository and the effects on regulatory compliance

    International Nuclear Information System (INIS)

    Aines, R.D.

    1986-04-01

    This paper discusses preliminary estimates of the release of radionuclides from waste packages containing glass-based waste forms under the expected conditions at Yucca Mountain. These estimates can be used to evaluate the contribution of waste package performance toward meeting repository regulatory restrictions on radionuclide release. Glass waste will be held in double stainless steel canisters. After failure of the container sometime after the 300 to 1000 year containment period, the open headspace in these cans will provide the only area where standing water can accumulate and react with the glass. A maximum release rate of 0.177 g/m 2 x year or 1.3 grams per year was obtained. Normalized loss of 1.3 grams per year corresponds to 0.08 parts in 100,000 per year of the 1660 kg reference weight of DWPF glass

  19. Aspects of radiation exposure amongst the population after release of radionuclides from terminal stores

    International Nuclear Information System (INIS)

    Proehl, G.; Mueller, H.; Paretzke, H.G.

    1989-08-01

    The release of radionuclides from terminal stores may lead to the contamination of ground water lying close to the surface, after the radionuclides have migrated within the covering rock. Use of this water can result in radiation exposure for human beings along many exposure pathways. In order to assess the radiation exposure from these exposure pathways the model ECOSYS-87-B was developed, as an extension of ECOSYS (Jacobi et al. 1985). On the basis of a standardized contamination of the ground water, the potential radiation exposure of a one-year-old and an adult are calculated, under the assumption that the entire food supply of these persons was produced using radioactively contaminated water. Special questions on the transfer of radionuclides in food chains are discussed, and, in particular, the mineral content of the water and the influence of the chemical form of the radionuclides dissolved in the ground water on their transfer within the food chain are explained. There is also a study of the extent to which various physiologically-based nutritional habits influence the radiation exposure of a human being. Various criteria for the evaluation of radiation exposure are discussed. (orig./HP) [de

  20. Effects of indoor residence on radiation doses from routine releases of radionuclides to the atmosphere

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1980-01-01

    Dose reduction factors from indoor residence during routine releases of radionuclides to the atmosphere were studied using models that are suitable for application to arbitrary source terms. Dose reduction factors for internal exposure to inhaled radionuclides account for air ventilation and deposition on inside building surfaces. Estimated internal dose reduction factors are approx. 0.2 to 0.8 for particulates and 0.07 to 0.4 for radioiodine. Dose reduction factors for external photon exposure from airborne and surface-deposited sources are based on the point-kernel integration method. Values for source terms from a fuel reprocessing plant and a hypothetical reactor accident are within a factor of 2 of the value 0.5 adopted by the US Nuclear Regulatory Commission (NRC) for population dose assessments. For the release at Three Mile Island nuclear station, however, the external dose reduction factor may be an order of magnitude less than the value adopted by the NRC

  1. UFOING: A program for assessing the off-site consequences from ingestion of accidentally released radionuclides

    International Nuclear Information System (INIS)

    Steinhauer, C.

    1988-12-01

    The program UFOING estimates foodchain-related consequences following accidental releases of radionuclides to the atmosphere. It was developed as a stand-alone supplement to the accident consequence assessment program system UFOMOD to allow faster and more detailed investigations of the consequences arising from the foodchain pathways than possible with the version of UFOING which is implemented in UFOMOD. For assumed releases at different times of the year, age dependent individual doses, collective doses, individual risks for fatal stochastic somatic health effects as a function of time, the total numbers of the effects, and the areas affected by foodbans together with the estimated duration of the bans are calculated. In addition, percentage contributions of radionuclides and foodstuffs to the doses and risks can be evaluated. In the first part of this report, an overview over the program is given. The other parts contain a user's guide, a program guide, and descriptions of the data employed and of the version of UFOING which is implemented in UFOMOD. (orig.) [de

  2. Balance and behavior of gaseous radionuclides released during initial fast reactor fuel reprocessing operations

    International Nuclear Information System (INIS)

    Leudet, A.; Goumondy, J.P.; Charrier, G.

    1985-10-01

    Five pins from the fast reactor Phenix are cut and dissolved in a specially designed cell for the accurate determination of gas released during the operation. Amount and activity of gaseous radionuclides: Kr, Xe, Kr-85, I, I-129, H-3 and C-14 are determined in the fuel pins and also their distribution between shearing and dissolution [fr

  3. SUBDOSA: a computer program for calculating external doses from accidental atmospheric releases of radionuclides

    International Nuclear Information System (INIS)

    Strenge, D.L.; Watson, E.C.; Houston, J.R.

    1975-06-01

    A computer program, SUBDOSA, was developed for calculating external γ and β doses to individuals from the accidental release of radionuclides to the atmosphere. Characteristics of SUBDOSA are: doses from both γ and β radiation are calculated as a function of depth in tissue, summed and reported as skin, eye, gonadal, and total body dose; doses are calculated for releases within each of several release time intervals and nuclide inventories and atmospheric dispersion conditions are considered for each time interval; radioactive decay is considered during the release and/or transit using a chain decay scheme with branching to account for transitions to and from isomeric states; the dose from gamma radiation is calculated using a numerical integration technique to account for the finite size of the plume; and the program computes and lists the normalized air concentrations at ground level as a function of distance from the point of release. (auth)

  4. Radionuclide toxicity

    International Nuclear Information System (INIS)

    Galle, P.

    1982-01-01

    The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

  5. HADOC: a computer code for calculation of external and inhalation doses from acute radionuclide releases

    International Nuclear Information System (INIS)

    Strenge, D.L.; Peloquin, R.A.

    1981-04-01

    The computer code HADOC (Hanford Acute Dose Calculations) is described and instructions for its use are presented. The code calculates external dose from air submersion and inhalation doses following acute radionuclide releases. Atmospheric dispersion is calculated using the Hanford model with options to determine maximum conditions. Building wake effects and terrain variation may also be considered. Doses are calculated using dose conversion factor supplied in a data library. Doses are reported for one and fifty year dose commitment periods for the maximum individual and the regional population (within 50 miles). The fractional contribution to dose by radionuclide and exposure mode are also printed if requested

  6. Gas generation in SFL 3-5 and effects on radionuclide release

    International Nuclear Information System (INIS)

    Skagius, K.; Lindgren, M.; Pers, K.

    1999-12-01

    A deep repository, SFL 3-5, is presently planned for disposing of long-lived low- and intermediate-level waste. In this study the amounts of gas that can be generated in the waste packages and in the vaults are estimated. The potential gas pressure build-up, the displacement of contaminated water and the consequences on radionuclide release from the engineered barriers in the repository are also addressed. The study is focussed on the repository design and waste inventory that was defined for the prestudy of SFL 3-5. Since the reporting of the prestudy the design of the repository has been modified and the waste inventory has been updated and a preliminary safety assessment of the repository has been carried out based on the new design and updated waste inventory. The implications on gas generation and release of these modifications in design and waste inventory are briefly addressed in this study

  7. Gas generation in SFL 3-5 and effects on radionuclide release

    Energy Technology Data Exchange (ETDEWEB)

    Skagius, K.; Lindgren, M.; Pers, K. [Kemakta Konsult AB, Stockholm (Sweden)

    1999-12-01

    A deep repository, SFL 3-5, is presently planned for disposing of long-lived low- and intermediate-level waste. In this study the amounts of gas that can be generated in the waste packages and in the vaults are estimated. The potential gas pressure build-up, the displacement of contaminated water and the consequences on radionuclide release from the engineered barriers in the repository are also addressed. The study is focussed on the repository design and waste inventory that was defined for the prestudy of SFL 3-5. Since the reporting of the prestudy the design of the repository has been modified and the waste inventory has been updated and a preliminary safety assessment of the repository has been carried outbased on the new design and updated waste inventory. The implications on gas generation and release of these modifications in design and waste inventory are briefly addressed in this study.

  8. Operational control of material release and discharges from nuclear power plant

    International Nuclear Information System (INIS)

    Szabo, I. C.; Ranga, T.; Daroczi, L.; Deme, S.; Kerekes, A.

    2003-01-01

    The operational control of radioactive materials during atmospheric release and aquatic discharge from nuclear power plant is a licensing criterion for NPPs. Originally at the Paks NPP the release control was based on activity limits for four groups of elements. These groups were noble gases, long living radio-aerosols, radioiodine and radiostrontium for atmospheric release and specified activity limit for beta emitters, strontium and tritium for aquatic discharge into Danube. These groups were controlled with proper sampling and/or measuring instrumentation. The limit for atmospheric release was given as a 30-day moving average, for liquid discharges the annual limit was stipulated. The new release and discharge limitation system is based on the environmental dose limitation. The dose constraint for Paks NPP is 90 Sv/year of the critical group for all release pathways and the investigation dose limit is equal to 27 Sv/year. The regulation did not subdivide the dose limit for atmospheric and liquid components but for operational control subdivision of dose limits for atmospheric release and aquatic discharge and shorter time period (one day-one month) seems to be useful. The subdivision can be based on past release data and/or previous activity limits. To satisfy dose below the investigation dose limit there should be a proper operation control level for each separately measured component and pathway belonging to reasonable time interval significantly shorter than one year. The main task of the NPP staff is elaboration of reasonable control levels and reference time intervals for different radionuclide and element groups to be used in operational control. Operational control levels are based on measured daily or monthly release rates. In case of noble gases, aerosols and iodine the daily release rates have several sharp peaks per year. Operational control levels give opportunity to detect these peaks for internal investigation purposes. Investigation release limits

  9. Dispersion of radionuclides potentially released from the Atolls of Mururoa and Fangataufa to neighboring archipelagos

    International Nuclear Information System (INIS)

    Osvath, I.

    1999-01-01

    This paper presents a compartmental model developed to simulate dispersion of radionuclides released to the ocean from the atolls of Mururoa and Fangataufa on a scale of 3000 x 1700 km (150 deg. to 300 deg. S latitude, 130 deg. to 160 deg. W longitude), including the Tuamotu, Cook, Society, Gambier and Austral archipelagos

  10. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, Linda [Stockholm Univ. (Sweden). Dept. of Systems Ecology; Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2004-09-01

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment.

  11. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    International Nuclear Information System (INIS)

    Kumblad, Linda

    2004-09-01

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment

  12. Radionuclide release calculations for selected severe accident scenarios

    International Nuclear Information System (INIS)

    Denning, R.S.; Leonard, M.T.; Cybulskis, P.; Lee, K.W.; Kelly, R.F.; Jordan, H.; Schumacher, P.M.; Curtis, L.A.

    1990-08-01

    This report provides the results of source term calculations that were performed in support of the NUREG-1150 study. ''Severe Accident Risks: An Assessment for Five US Nuclear Power Plants.'' This is the sixth volume of a series of reports. It supplements results presented in the earlier volumes. Analyses were performed for three of the NUREG-1150 plants: Peach Bottom, a Mark I, boiling water reactor; Surry, a subatmospheric containment, pressurized water reactor; and Sequoyah, an ice condenser containment, pressurized water reactor. Complete source term results are presented for the following sequences: short term station blackout with failure of the ADS system in the Peach Bottom plant; station blackout with a pump seal LOCA for the Surry plant; station blackout with a pump seal LOCA in the Sequoyah plant; and a very small break with loss of ECC and spray recirculation in the Sequoyah plant. In addition, some partial analyses were performed which did not require running all of the modules of the Source Term Code Package. A series of MARCH3 analyses were performed for the Surry and Sequoyah plants to evaluate the effects of alternative emergency operating procedures involving primary and secondary depressurization on the progress of the accident. Only thermal-hydraulic results are provided for these analyses. In addition, three accident sequences were analyzed for the Surry plant for accident-induced failure of steam generator tubes. In these analyses, only the transport of radionuclides within the primary system and failed steam generator were examined. The release of radionuclides to the environment is presented for the phase of the accident preceding vessel meltthrough. 17 refs., 176 figs., 113 tabs

  13. Radionuclide Retention in Concrete Wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  14. Decision analysis of countermeasures for the milk pathway after an accidental release of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Ammann, M.; Sinkko, K.; Kostiainen, E.; Salo, E.; Liskola, K.; Haemaelaeinen, R.P.; Mustajoki, J

    2001-12-01

    A facilitated workshop was arranged to plan countermeasures that could reduce the dose arising from the consumption of radionuclide-contaminated milk products. It was assumed that a hypothetical accident in a nuclear facility had led to the release of considerable amounts of radionuclides, which subsequently spread across one of Finland's most important agricultural regions and contaminated the milk produced there. The participants in the workshop, interest groups on food issues, considered all the factors influencing the countermeasure decision, not only radiological or monetary ones but less tangible psychosocial effects as well. The participants preferred the countermeasures provision of uncontaminated fodder and production control to banning and disposal. The analysis showed that these countermeasures could be implemented even if the radionuclide concentrations in foodstuffs were below internationally recommended intervention levels. Banning and withdrawal of milk products from sale was not a favourable option, because of the high costs and disadvantages to producers and the industry, and because the disposal of enormous amounts of milk causes a considerable environmental problem. The study revealed the need to further develop methods to realistically assess the radiological and cost implications of food countermeasures. The feasibility and constraints of actions also need further investigation. The experience gained strongly supports the format of a facilitated workshop to tackle a decision problem that concerns different stakeholders. The participants considered the workshop and the decision analysis very useful in exercises. They also expected a similar approach to be applicable in a real situation, although the suitability was not rated as high as for exercises. It is concluded that a facilitated workshop is a valuable instrument for emergency management and in exercises, when revising emergency plans or in order to identify issues that need to be

  15. Solubility limited radionuclide transport through geologic media

    International Nuclear Information System (INIS)

    Muraoka, Susumu; Iwamoto, Fumio; Pigford, T.H.

    1980-11-01

    Prior analyses for the migration of radionuclides neglect solubility limits of resolved radionuclide in geologic media. But actually some of the actinides may appear in chemical forms of very low solubility. In the present report we have proposed the migration model with no decay parents in which concentration of radionuclide is limited in concentration of solubility in ground water. In addition, the analytical solutions of the space-time-dependent concentration are presented in the case of step release, band release and exponential release. (author)

  16. Radiation protection aspects of the trafficking radionuclides contaminated metal scrap

    International Nuclear Information System (INIS)

    Prouza, Z.

    1999-01-01

    This paper covers the legal base of the release in the environment of radionuclides containing materials and the radiation protection aspects of trafficking in radionuclides contaminated materials. Materials, substance and objects containing radionuclides or contaminated by them may be released into the environment, if they do not exceed values authorized by SONS (State Office of Nuclear Safety). Legislative measures should be taken against illicit trafficking of the nuclear material in all the areas. The creation of a sophisticated system for the control and regulation of all important radionuclides released into the environment should be based on the radiation protection limits, constraints, reference and exemption levels which are introduced in the legislative documents; the strong supervision of producers and users of the sealed sources by SONS side, in addition to the requirements of the licensing process of their sources; a complete data-base and information exchange system related to illicit trafficking in contaminated material; in this system all the authorities with jurisdiction should be involved. The responsibilities of the persons involved in metal scrap trafficking should include arrangement of appropriate monitoring, rules for transport of the metal scrap, an adequate measuring system to monitor metal scrap including monitoring to prevent processing or smelting of the radioactive material, control measures, etc. All of the above items of legislation are an important challenge for the Czech Republic. (author)

  17. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Assessment of radionuclide release scenarios for the repository system 2012

    International Nuclear Information System (INIS)

    2012-12-01

    Assessment of Radionuclide Release Scenarios sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of presenting an assessment of the repository system scenarios leading to radionuclide releases that have been identified in Formulation of Radionuclide Release Scenarios. A base scenario, variant scenarios and disturbance scenarios are considered. For each scenario, a range of calculation cases, also identified in Formulation of Radionuclide Release Scenarios, has been analysed, complemented by Monte Carlo simulations, a probabilistic sensitivity analysis and other supporting calculations. The calculation cases and analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in Performance Assessment. Quality control and assurance measures have been adopted to ensure transparency and traceability of the calculations performed and hence to promote confidence in the analysis of the calculation cases. The calculation cases each consider a single, failed canister, where three possible modes of failure are addressed: (1) the presence of an initial penetrating defect in the copper overpack of the canister, (2) corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion, (3) shear movement on a fracture intersecting a deposition hole. The likelihood and consequences of multiple canister failure occurring during the assessment time frame are also considered. In particular, the analyses consider: The likelihood and consequences of there being multiple canisters with initial penetrating defects; The consequences if canister failure due to corrosion following buffer erosion were to occur; and The low annual probability of there being an earthquake large enough to give rise to canister failure due to rock shear movements and the potential consequences of such an earthquake, taking into

  18. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Assessment of radionuclide release scenarios for the repository system 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    Assessment of Radionuclide Release Scenarios sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of presenting an assessment of the repository system scenarios leading to radionuclide releases that have been identified in Formulation of Radionuclide Release Scenarios. A base scenario, variant scenarios and disturbance scenarios are considered. For each scenario, a range of calculation cases, also identified in Formulation of Radionuclide Release Scenarios, has been analysed, complemented by Monte Carlo simulations, a probabilistic sensitivity analysis and other supporting calculations. The calculation cases and analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in Performance Assessment. Quality control and assurance measures have been adopted to ensure transparency and traceability of the calculations performed and hence to promote confidence in the analysis of the calculation cases. The calculation cases each consider a single, failed canister, where three possible modes of failure are addressed: (1) the presence of an initial penetrating defect in the copper overpack of the canister, (2) corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion, (3) shear movement on a fracture intersecting a deposition hole. The likelihood and consequences of multiple canister failure occurring during the assessment time frame are also considered. In particular, the analyses consider: The likelihood and consequences of there being multiple canisters with initial penetrating defects; The consequences if canister failure due to corrosion following buffer erosion were to occur; and The low annual probability of there being an earthquake large enough to give rise to canister failure due to rock shear movements and the potential consequences of such an earthquake

  19. SKB WP-cave project. Radionuclide release from the near-field in a WP-cave repository

    International Nuclear Information System (INIS)

    Lindgren, M.; Skagius, K.

    1989-04-01

    The release of radionuclides from the bentonite-sand barrier (near-field) in a WP-cave repository for high level radioactive waste has been studied. Calculations were made for two cases; a Low Flow Through Case and a High Flow Through Case. The difference between the two cases lies in the assumed hydraulic properties of the bentonite-sand barrier and the system inside the barrier. The effect on the nuclide release of solubility limitations, sorption capacity of the barriers, radiolytic fuel oxidation rate as well as the thickness of the bentonite-sand barrier, were also investigated for the Low Flow Through Case. (authors)

  20. Colloid-facilitated radionuclide transport: a regulatory perspective

    Science.gov (United States)

    Dam, W. L.; Pickett, D. A.; Codell, R. B.; Nicholson, T. J.

    2001-12-01

    What hydrogeologic-geochemical-microbial conditions and processes affect migration of radionuclides sorbed onto microparticles or native colloid-sized radionuclide particles? The U.S. Nuclear Regulatory Commission (NRC) is responsible for protecting public health, safety, and the environment at numerous nuclear facilities including a potential high-level nuclear waste disposal site. To fulfill these obligations, NRC needs to understand the mechanisms controlling radionuclide release and transport and their importance to performance. The current focus of NRC staff reviews and technical interactions dealing with colloid-facilitated transport relates to the potential nuclear-waste repository at Yucca Mountain, Nevada. NRC staff performed bounding calculations to quantify radionuclide releases available for ground-water transport to potential receptors from a Yucca Mountain repository. Preliminary analyses suggest insignificant doses of plutonium and americium colloids could be derived from spent nuclear fuel. Using surface complexation models, NRC staff found that colloids can potentially lower actinide retardation factors by up to several orders of magnitude. Performance assessment calculations, in which colloidal transport of plutonium and americium was simulated by assuming no sorption or matrix diffusion, indicated no effect of colloids on human dose within the 10,000 year compliance period due largely to long waste-package lifetimes. NRC staff have identified information gaps and developed technical agreements with the U.S. Department of Energy (DOE) to ensure sufficient information will be presented in any potential future Yucca Mountain license application. DOE has agreed to identify which radionuclides could be transported via colloids, incorporate uncertainties in colloid formation, release and transport parameters, and conceptual models, and address the applicability of field data using synthetic microspheres as colloid analogs. NRC is currently

  1. Radionuclide release rate inversion of nuclear accidents in nuclear facility based on Kalman filter

    International Nuclear Information System (INIS)

    Tang Xiuhuan; Bao Lihong; Li Hua; Wan Junsheng

    2014-01-01

    The rapidly and continually back-calculating source term is important for nuclear emergency response. The Gaussian multi-puff atmospheric dispersion model was used to produce regional environment monitoring data virtually, and then a Kalman filter was designed to inverse radionuclide release rate of nuclear accidents in nuclear facility and the release rate tracking in real time was achieved. The results show that the Kalman filter combined with Gaussian multi-puff atmospheric dispersion model can successfully track the virtually stable, linear or nonlinear release rate after being iterated about 10 times. The standard error of inversion results increases with the true value. Meanwhile extended Kalman filter cannot inverse the height parameter of accident release as interceptive error is too large to converge. Kalman filter constructed from environment monitoring data and Gaussian multi-puff atmospheric dispersion model can be applied to source inversion in nuclear accident which is characterized by static height and position, short and continual release in nuclear facility. Hence it turns out to be an alternative source inversion method in nuclear emergency response. (authors)

  2. A dynamic compartment model for evaluating transfer of radionuclide into rice-plant after acute release

    International Nuclear Information System (INIS)

    Keum, D.K.; Lee, H.S.; Choi, H.J.; Kang, H.S.; Lee, C.W.

    2004-01-01

    In this paper a dynamic compartment model is presented to estimate the transfer of radionuclides deposited on rice-fields after an accidental release. The present model includes a surface water compartment and a direct shoot-base absorption from the surface water to the rice plant to account for the flooded condition of rice-fields, which are major features discriminating the present model from the existing model. In order to test the validity of model, a number of simulated Cs-137 deposition experiments were performed while growing rice-plant in a green house. For the experiments the radionuclide was indirectly treated in the root zone soil before transplanting and on the surface water without a direct contamination of rice-plant after transplanting. In the first year of deposition the shoot-base absorption was a predominant process for the transfer of radionuclide into rice when the radionuclide was treated on the surface water, and from the second year, the root-uptake was dominant. The model calculation predicted reasonably well the first year experimental result showing the importance of shoot base absorption as well as the concentration of rice-body and grain measured from respective rice-plant grown consecutively on the contaminated soils for years. (author)

  3. Assessment of Westinghouse Hanford Company methods for estimating radionuclide release from ground disposal of waste water at the N Reactor sites

    International Nuclear Information System (INIS)

    1988-09-01

    This report summarizes the results of an independent assessment by Golder Associates, Inc. of the methods used by Westinghouse Hanford Company (Westinghouse Hanford) and its predecessors to estimate the annual offsite release of radionuclides from ground disposal of cooling and other process waters from the N Reactor at the Hanford Site. This assessment was performed by evaluating the present and past disposal practices and radionuclide migration data within the context of the hydrology, geology, and physical layout of the N Reactor disposal site. The conclusions and recommendations are based upon the available data and simple analytical calculations. Recommendations are provided for conducting more refined analyses and for continued field data collection in support of estimating annual offsite releases. Recommendations are also provided for simple operational and structural measures that should reduce the quantities of radionuclides leaving the site. 5 refs., 9 figs., 1 tab

  4. Modeling Radionuclide Decay Chain Migration Using HYDROGEOCHEM

    Science.gov (United States)

    Lin, T. C.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

    2014-12-01

    Nuclear technology has been employed for energy production for several decades. Although people receive many benefits from nuclear energy, there are inevitably environmental pollutions as well as human health threats posed by the radioactive materials releases from nuclear waste disposed in geological repositories or accidental releases of radionuclides from nuclear facilities. Theoretical studies have been undertaken to understand the transport of radionuclides in subsurface environments because that the radionuclide transport in groundwater is one of the main pathway in exposure scenarios for the intake of radionuclides. The radionuclide transport in groundwater can be predicted using analytical solution as well as numerical models. In this study, we simulate the transport of the radionuclide decay chain using HYDROGEOCHEM. The simulated results are verified against the analytical solution available in the literature. Excellent agreements between the numerical simulation and the analytical are observed for a wide spectrum of concentration. HYDROGECHEM is a useful tool assessing the ecological and environmental impact of the accidental radionuclide releases such as the Fukushima nuclear disaster where multiple radionuclides leaked through the reactor, subsequently contaminating the local groundwater and ocean seawater in the vicinity of the nuclear plant.

  5. Radionuclides and isotopes release of spent fuel matrix. Conceptual and mathematical models of wastes behaviour; Liberacion de los radionucleidos e isotopos estables contenidos en la matriz del combustible. Modelo conceptual y modelo matematico del comportamiento del residuo

    Energy Technology Data Exchange (ETDEWEB)

    Cera, E.; Merino, J.; Bruno, J.

    2000-07-01

    We have developed a conceptual and numerical model to calculate release of selected radionuclides from spent fuel under repository condition. This has been done in the framework of the Enresa 2000 performance assessment exercise. The model has been developed based on kinetic mass balance equations in order to study the evolution of the spent fuel water interface as a function of time. Several processes have been kinetically modelled: congruent dissolution, radioactive decay, ingrowth and water turnover in the gap. The precipitation/redissolution of secondary solid phases has been taken into account from a thermodynamic point of view. Both approaches have been coupled and the resulting equations solved for a number of radionuclides in both, a conservative and realistic approach. The results show three distinct groups of radionuclides based on their release behaviour: a first group is composed of radioisotopes of highly insoluble elements (e. g., Pu, Am, Pd) whose concentration in the gap is mainly controlled by their solubility and therefore their evolution is identical in both cases. Secondly, a set of radionuclides from soluble elements under these conditions (e. g., I, Cs, Ra) show concentrations kinetically controlled, decreasing with time following the congruent dissolution trend. Their release concentrations are one order of magnitude larger in the conservative case than in the realistic case. Finally, a third group has been identified (e. g., Se, Th, Cm) where a mixed behaviour takes place: initially their solubility limiting phases control their concentration in the gap but the situation reverts to a kinetic control as the chemical conditions change and the secondary precipitates become totally dissolved. The fluxes of the different radionuclides are also given as an assessment of the source term in the performance assessment. (Author)

  6. Characterization of a Planetary Boundary Layer model to evaluate radionuclides releases in nuclear installations

    International Nuclear Information System (INIS)

    Molnary, Leslie de

    1993-01-01

    A two layer bulk model is used to simulate numerically the time and spatial evolution of concentration of radionuclides in the Planetary Boundary Layer (PBL) for convective and stable conditions. In this model, the closure hypothesis are based on the integrated version of the Turbulent Kinetics Energy (TKE) equation (Smeda,1979). This type of model was adopted here because it is numerically simple to be applied operationally in routine and emergency support systems of atmospheric releases at nuclear power plants, and the hypothesis of the efficiency of the vertical mixing seems to be physically reasonable to simulated PBL evolution for high wind conditions and stable conditions in Subtropical latitudes regions. In order to validate the model to the nuclear power plants of the Centro Experimental Aramar (CEA), located in Ipero, State of Sao Paulo, Brazil, numerical simulations were carried out with initial and boundary conditions based on vertical profiles of temperature and horizontal wind speed and direction obtained from tethered balloon soundings, synoptic charts at 850 hPa and surface observations. Comparisons between a 24 hour long numerical simulation and observations indicate that the model is capable of reproduce the diurnal evolution of temperature and horizontal wind during the convective regime. During stable conditions, the slab model was able to simulate the intensity of the surface inversion as a difference between the mixed layer and surface temperatures. The simulated mixed layer height matches with observations during the convective and stable regime. A daytime release of radionuclides was simulated for CEA region and the results indicated that the maximum relative concentration reaches a distance about 15 Km in 1 hour, varing from 100 times background at the moment of the release to 15 times the background. For night releases, the maximum concentration reaches the same distance in 45 minutes, varing from 100 to 30 times the background values

  7. Radionuclide Retention in Concrete Wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

    2011-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

  8. Development of a general model to predict the rate of radionuclide release (source term) from a low-level waste shallow land burial facility

    International Nuclear Information System (INIS)

    Sullivan, T.M.; Kempf, C.R.; Suen, C.J.; Mughabghab, S.M.

    1988-01-01

    Federal Code of Regulations 10 CFR 61 requires that any near surface disposal site be capable of being characterized, analyzed, and modeled. The objective of this program is to assist NRC in developing the ability to model a disposal site that conforms to these regulations. In particular, a general computer model capable of predicting the quantity and rate of radionuclide release from a shallow land burial trench, i.e., the source term, is being developed. The framework for this general model has been developed and consists of four basic compartments that represent the major processes that influence release. These compartments are: water flow, container degradation, release from the waste packages, and radionuclide transport. Models for water flow and radionuclide transport rely on the use of the computer codes FEMWATER and FEMWASTE. These codes are generally regarded as being state-of-the-art and required little modification for their application to this project. Models for container degradation and release from waste packages have been specifically developed for this project. This paper provides a brief description of the models being used in the source term project and examples of their use over a range of potential conditions. 13 refs

  9. The calculating methods of the release of airborne radionuclides to environment during the normal operation of a module high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Liu Yuanzhong

    1993-01-01

    The calculations of the release of radionuclides to environment are the basis of environmental impact assessment during the normal operation of a module high temperature gas-cooled reactor of the Institute of Nuclear Energy Technology, Tsinghua University, China. According to the features of the reactor it is pointed out that only five sources of the airborne radioactive materials released to environment are important. They are: (1) the activation of the air in the reactor cavity; (2) the escape from the primary coolant systems; (3) the release of radioactively contaminated helium from storage tanks; (4) the release of radioactively contaminated helium from the gas evacuation system of fuel load and unload system; (5) the leakage of the vapour from water-steam loop. In accordance with five release sources the calculating methods of radionuclides released to environment are worked out respectively and the respective calculating formulas are derived for the normal operation of the reactor

  10. Assessing the impact of releases of radionuclides into sewage systems in urban environment - simulation, modelling and experimental studies - LUCIA

    Energy Technology Data Exchange (ETDEWEB)

    Sundelll-Bergman, S. (Vattenfall Power Consultant, Stockholm (Sweden)); Avila, R.; Cruz, I. de la (Facilia AB, (Sweden)); Xu, S. (Swedish Radiation Safety Authority, (Sweden)); Puhakainen, M.; Heikkinene, T.; Rahola, T. (STUK (Finland)); Hosseini, A. (Norwegian Radiation Protection Authority (Norway)); Nielsen, Sven (Risoe National Laboratory for Sustainable Energy, DTU (Denmark)); Sigurgeirsson, M. (Geislavarnir rikisins (Iceland))

    2009-06-15

    This report summarises the findings of a project on assessing the impact of releases of radionuclides into sewage systems and was established to provide more knowledge and suitable tools for emergency preparedness purposes in urban areas. It was known that the design of sewage plants, and their wastewater treatments, is rather similar between the Nordic countries. One sewage plant in each of the five Nordic countries was selected for assessing the impact of radionuclide releases from hospitals into their sewerage systems. Measurements and model predictions of dose assessments to different potentially exposed members of the public were carried out. The results from the dose assessments indicate that in case of routine releases annual doses to the three hypothetical groups of individuals are most likely insignificant. Estimated doses for workers are below 10 muSv/y, for the two studied radionuclides 99mTc and 131I. If uncertainties in the predictions of activity concentrations in sludge are considered, then the probability of obtaining doses above 10 muSv/y may not be insignificant. The models and approaches developed can also be applied in case of accidental releases. A laboratory inter-comparison exercise was also organised to compare analytical results across the laboratories participating in the project, using both 131I, dominating man-made radionuclide in sewage systems due to the medical use. A process oriented model of the biological treatment is also proposed in the report that does not require as much input data as for the LUCIA model. This model is a combination of a simplified well known Activated Sludge Model No.1 (Henze, 1987) and the Kd concept used in the LUCIA model. The simplified model is able to estimate the concentrations and the retention time of the sludge in different parts of the treatment plant, which in turn, can be used as a tool for the dose assessment purpose.filled by the activity. (au)

  11. Assessing the impact of releases of radionuclides into sewage systems in urban environment - simulation, modelling and experimental studies - LUCIA

    International Nuclear Information System (INIS)

    Sundelll-Bergman, S.; Avila, R.; Cruz, I. de la; Xu, S.; Puhakainen, M.; Heikkinene, T.; Rahola, T.; Hosseini, A.; Nielsen, Sven; Sigurgeirsson, M.

    2009-06-01

    This report summarises the findings of a project on assessing the impact of releases of radionuclides into sewage systems and was established to provide more knowledge and suitable tools for emergency preparedness purposes in urban areas. It was known that the design of sewage plants, and their wastewater treatments, is rather similar between the Nordic countries. One sewage plant in each of the five Nordic countries was selected for assessing the impact of radionuclide releases from hospitals into their sewerage systems. Measurements and model predictions of dose assessments to different potentially exposed members of the public were carried out. The results from the dose assessments indicate that in case of routine releases annual doses to the three hypothetical groups of individuals are most likely insignificant. Estimated doses for workers are below 10 μSv/y, for the two studied radionuclides 99mTc and 131I. If uncertainties in the predictions of activity concentrations in sludge are considered, then the probability of obtaining doses above 10 μSv/y may not be insignificant. The models and approaches developed can also be applied in case of accidental releases. A laboratory inter-comparison exercise was also organised to compare analytical results across the laboratories participating in the project, using both 131I, dominating man-made radionuclide in sewage systems due to the medical use. A process oriented model of the biological treatment is also proposed in the report that does not require as much input data as for the LUCIA model. This model is a combination of a simplified well known Activated Sludge Model No.1 (Henze, 1987) and the Kd concept used in the LUCIA model. The simplified model is able to estimate the concentrations and the retention time of the sludge in different parts of the treatment plant, which in turn, can be used as a tool for the dose assessment purpose.filled by the activity. (au)

  12. Comparison of the COMRADEX-IV and AIRDOS-EPA methodologies for estimating the radiation dose to man from radionuclide releases to the atmosphere

    International Nuclear Information System (INIS)

    Miller, C.W.; Hoffman, F.O.; Dunning, D.E. Jr.

    1981-01-01

    This report presents a comparison between two computerized methodologies for estimating the radiation dose to man from radionuclide releases to the atmosphere. The COMRADEX-IV code was designed to provide a means of assessing potential radiological consequences from postulated power reactor accidents. The AIRDOS-EPA code was developed primarily to assess routine radionuclide releases from nuclear facilities. Although a number of different calculations are performed by these codes, three calculations are in common - atmospheric dispersion, estimation of internal dose from inhalation, and estimation of external dose from immersion in air containing gamma emitting radionuclides. The models used in these calculations were examined and found, in general, to be the same. Most differences in the doses calculated by the two codes are due to differences in values chosen for input parameters and not due to model differences. A sample problem is presented for illustration

  13. RESUS: A code for low volatile radio-nuclide release from liquids due to vapor bubble burst induced liquid jet formation and disintegration

    International Nuclear Information System (INIS)

    Koch, M.K.; Starflinger, J.; Linnemann, Th.; Brockmeier, U.; Unger, H.; Schuetz, W.

    1995-01-01

    In the field of nuclear safety, the release of volatile and low volatile radio-nuclides from liquid surfaces into a gas atmosphere is important for aerosol source term considerations particularly in late severe accident sequences. In case of a hypothetical nuclear reactor accident involving a failure of the primary system, primary coolant and radio-nuclides may be released into the containment to frequently form a liquid pool which may be contaminated by suspended or solved fuel particles and fission products. Under this scope, the release code package REVOLS/RENONS was developed for radio-nuclide release from liquid surfaces. Assuming the absence of gas or vapor bubbles in the liquid, the evaporative release of volatile components, calculated by the REVOLS code, is governed by diffusive and convective transport processes, whereas the release of low volatiles, calculated by the RENONS code, may be governed by mechanical processes which leads to droplet entrainment in case of wavy liquid pool surface conditions into the containment atmosphere by means of convection. For many accident sequences, in which gas is injected into a pool or liquid area elsewhere, predominantly when saturation temperatures can be reached, the release of low volatile species from liquid surfaces due to bubble burst is identified as a decisive release mechanism also. Together with the liquid, the particles which are located at the pool surface or suspended in the pool, are released into the atmosphere. Consequently, the code RESUS.MOD1 (RESUSpension) is presently extended to include the calculation of the release of droplets and suspended radio-nuclide particles due to bubble burst induced liquid jet formation and disintegration above liquid surfaces. Experimental investigations indicate the influence of bubble volume and shape at the pool surface as well as bubble stabilization or destabilization, and furthermore the system pressure and temperatures as well as fluid properties, on droplet

  14. Pathways and estimated consequences of radionuclide releases from a nuclear power plant

    International Nuclear Information System (INIS)

    Nilsson, Mats.

    1981-03-01

    The radioactive corrosion products 60 Co, 58 Co, 54 Mn, 65 Zn, 51 Cr and 110 Agsp(m) which are released from Barsebaeck Nuclear Power Plant (Sweden) into the marine environment have been studied. The brown seaweed Fucus vesiculosus has been found to be excellent bioindicator for these radionuclides. The distribution of activation products along the west coast of Sweden has been studied and can very well be described with a power function. Uptake and retention of the activation products in Fucus have been studied and results are reported. The activity concentration in Fucus well reflects the disharge rate from the power plant. Other bioindicators have been studied ; mainly the crustaceans Idothea and Gammarus. A simulation of 131 I-release following a fictious BWR 1 accident is described as well as a model for estimation of the individual and collective dose equivalents arising from intake of contaminated milk. (Author)

  15. Radionuclide behavior in water saturated porous media: Diffusion and infiltration coupling of thermodynamically and kinetically controlled radionuclide water - mineral interactions

    International Nuclear Information System (INIS)

    Spasennykh, M.Yu.; Apps, J.A.

    1995-05-01

    A model is developed describing one dimensional radionuclide transport in porous media coupled with locally reversible radionuclide water-mineral exchange reactions and radioactive decay. Problems are considered in which radionuclide transport by diffusion and infiltration processes occur in cases where radionuclide water-solid interaction are kinetically and thermodynamically controlled. The limits of Sr-90 and Cs-137 migration are calculated over a wide range of the problem variables (infiltration velocity, distribution coefficients, and rate constants of water-mineral radionuclide exchange reactions)

  16. Radionuclide Retention in Concrete Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

    2010-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

  17. Measurement of anthropogenic radionuclides in the atmosphere with a radionuclide monitoring network for nuclear tests

    International Nuclear Information System (INIS)

    Yonezawa, Chushiro; Yamamoto, Yoichi

    2011-01-01

    A worldwide radionuclide monitoring network for nuclear tests has detected the anthropogenic radioactive materials released in the atmosphere due to the accident of the Fukushima Daiichi Nuclear Power Plant impacted by the Great East Japan Earthquake on March 11, 2011. After four months have passed since the accident occurred, most overseas stations do not detect the radionuclides of Fukushima origin any more. The Takasaki station in Japan, however, is still detecting them every day. This paper describes radionuclide monitoring stations and the network of them as part of the International Monitoring System (IMS) in the Comprehensive Nuclear Test Ban Treaty (CTBT), as well as the measurement results of radionuclide particulates and radioactive isotopes of xenon released from the Fukushima Daiichi Nuclear Power Plant with the monitoring network. (J.P.N.)

  18. A review of radionuclide release and transport in recent in-pile experiments

    International Nuclear Information System (INIS)

    Harman, N.F.; Clough, P.N.

    1992-01-01

    The experimental series, reviewed in this work, are LOFT-LP-FP-2, PBF SFD ST to 1-4, Treat/STEP I to 4, and ACRR ST-1 and ST-2. These have the common features of in-core heating of a test fuel bundle to high temperatures (usually with some fuel melting) in an experimental reactor core, and of collecting and analysing the released fission products. They were designed to provide detailed information on the release from fuel of fission products and other radionuclides under LWR severe accident conditions, and on the chemical and physical forms and transport of the fission products. The main aim of this review is to bring together, in a systematic way, information on the conduct of the tests, on their successes and failures, and particularly on the information they generated on the chemical and physical behaviour of released fission products. By examining and analysing the data from all of the tests together, patterns of fission product behaviour may become apparent and insights may be gained, which would not be arrived at from individual test results. Moreover, important lessons may be learned, and useful guidance obtained, relating to the aims and conduct of future experimental programmes of fission product release from fuel and transport behaviour. The conclusions should be particularly relevant to the imminent Phebus-FP in-pile test series at Cadarache

  19. Estimation of radionuclide releases in atmosphere from Cernavoda NPP based on continuous gaseous effluent monitoring

    International Nuclear Information System (INIS)

    Bobric, E.; Murgoci, S.; Popescu, I.; Ibadula, R.

    2001-01-01

    Monitoring of gaseous effluents from Cernavoda NPP is performed to assess the environmental impact of the plant operation. The results of the monitoring program are used to evaluate the population doses in order to ensure that the emissions of radionuclides in air are below regulatory limits and radiation doses are maintained ALARA. It complements, but is independent from the Operational Environmental Monitoring Program for Cernavoda NPP. Gaseous effluent monitors provide continuous indication of the radioactivity content in atmospheric emissions. Except for noble gases, these monitors also collect samples for later detailed analysis in the station Health Physics Laboratory. This paper presents the main equipment and the results of the gaseous effluents monitoring program in order to assess the impact of Cernavoda NPP operation and to predict the future releases as function of radionuclides concentrations in CANDU systems, based on the identified trends.(author)

  20. Field studies of the atmospheric processing of radionuclides released at Chernobyl

    International Nuclear Information System (INIS)

    Slinn, W.G.N.; Brodzinski, R.L.; Busness, K.M.

    1987-01-01

    This report gives a summary description of the goals and execution of field studies to characterize the radionuclides released from Chernobyl and to examine their long-range atmospheric transport and processing. Starting on April 28, 1986, an intensive planning and preparation effort was mounted over a very short time intercept and characterize the Chernobyl plume on its arrival over the western US. During the execution of these studies, they had very little firm information (beyond their own measurements and trajectory estimates) to confirm the location of the Chernobyl plume. On May 20, 1986, the studies were terminated, after extensive airborne sampling of air, cloud water, precipitation, soil, and vegetation as the plume traversed the western and central US and moved into Canada

  1. Radionuclide transport in fractured rock: quantifying releases from final disposal of high level waste

    International Nuclear Information System (INIS)

    Silveira, Claudia S. da; Alvim, Antonio C.M.

    2013-01-01

    Crystalline rock has been considered as a potentially suitable matrix for high-level radioactive waste (HLW) repository because it is found in very stable geological formations and may have very low permeability. In this study the adopted physical system consists of the rock matrix containing a discrete horizontal fracture in a water saturated porous rock and a system of vertical fractures as a lineament. The transport in the fractures - horizontal and vertical, is assumed to obey a relation convection-diffusion, while the molecular diffusion is considered dominant mechanism of transport in porous rock. In this model the decay chain is considered. We use a code in Fortran 90, where the partial differential equations that describe the movement of radionuclides were discretized by finite differences methods. We use the fully implicit method for temporal discretization schemes. The simulation was performed with relevant data of nuclides in spent fuel for performance assessment in a hypothetical repository, thus quantifying the radionuclides released into the host rock. (author)

  2. Box model of radionuclide dispersion and radiation risk estimation for population in case of radioactivity release from nuclear submarine number-sign 601 dumped in the Kara Sea

    International Nuclear Information System (INIS)

    Yefimov, E.I.; Pankratov, D.V.; Ignatiev, S.V.

    1997-01-01

    When ships with nuclear reactors or nuclear materials aboard suffer shipwreck or in the case of burial or dumping of radioactive wastes, atmospheric fallout, etc., radionuclides may be released and spread in the sea, contaminating the sea water and the sea bottom. When a nuclear submarine (NS) is dumped this spread of activity may occur due to gradual core destruction by corrosion over many years. The objective of this paper is to develop a mathematical model of radionuclide dispersion and to assess the population dose and radiation risk for radionuclide release from the NS No. 601, with Pb-Bi coolant that was dumped in the Kara Sea

  3. Database construction for assessment of chronic radionuclide releases

    International Nuclear Information System (INIS)

    Hively, L.M.; Sjoreen, A.L.; Bledsoe, J.L.

    1986-01-01

    Oak Ridge National Laboratory (ORNL) has developed a comprehensive dose/risk assessment methodology, CRRIS (Computerized Radiological Risk Investigation System), for assessment of atmospheric radionuclide releases (e.g., during decontamination and decommissioning). Radiological effects are calculated for direct atmospheric and ground exposure and for consumption of contaminated agricultural products. Previously, population and agricultural data for CRRIS were tabulated on 1/2-degree square grid cells. This coarse resolution resulted in anomalies such as population in water bodies, agricultural production in city centers, and nonconservation of population over the assessment grid. An even finer mesh (2-minute square grid) is inadequate in densely populated cities where 20,000 or more people live in a square block. These difficulties are overcome by a higher resolution technique using US Census Bureau population data at the most detailed [enumeration district (ED)] level available and by excluding population from unpopulated areas (e.g., water bodies). Agricultural data are available at only the county level and are apportioned to the ED grid according to farm population, conserving the original data. This paper discusses the database construction using Tennessee as an illustration. 10 refs., 2 figs., 1 tab

  4. Radionuclide Retention in Concrete Wasteforms - FY13

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C.; Parker, Kent E.; Cordova, Elsa A.

    2013-10-15

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  5. Predicted radionuclide release from reactor-related unenclosed solid objects dumped in the Sea of Japan and the Pacific Ocean, east coast of Kamchatka

    International Nuclear Information System (INIS)

    Mount, M.E.; Lynn, N.M.; Warden, J.M.

    1996-06-01

    Between 1978 and 1991 reactor-related solid radioactive waste was dumped by the former Soviet Union as unenclosed objects in the Pacific Ocean, east coast of Kamchatka, and the Sea of Japan. This paper presented estimates for the current (1994) inventory of activation and corrosion products contained in the reactor-related unenclosed solid objects. In addition, simple models derived for prediction of radionuclide release from marine reactors dumped in the Kara Sea are applied to certain of the dumped objects to provide estimates of radionuclide release to the Pacific Ocean, east coast of Kamchatka, and Sea of Japan environments. For the Pacific Ocean, east coast of Kamchatka, total release rates start below 0.01 GBq yr -1 and over 1,000 years, fall to 100 Bq yr -1 . In the Sea of Japan, the total release rate starts just above 1 GBq yr - 1 , dropping off to a level less than 0.1 GBq yr -1 , extending past the year 4,000

  6. Emissions of the corrosion radionuclides in an atmosphere

    International Nuclear Information System (INIS)

    Vardanyan, M.

    2010-01-01

    In area of Armenian nuclear power plant location, in atmospheric air in majority of cases log two technogenic radionuclides: l 37 C s and 9 0 S r. Presence of these radionuclides basically is caused by global fall out (consequences of tests of the nuclear weapon and Chernobyl NPP accident), whose contribution to the contents of these radionuclides in atmosphere is incomparably greater, than emissions from the NPP. However there are some cases when in an atmosphere are registered the technogenic radionuclides, caused by emissions from NPP. In the present work such case is considered. Gas-aerosol releases of NPP in the atmosphere are carefully purified by means of various high-efficiency filters and gas-cleaning systems. Nevertheless, one should forecast and measure, the possible impact of these releases on the environment in the regions surrounding the NPP. Radioactive releases of the Armenian NPP (ANPP) contain the set of radionuclides characteristic for NPPs of this type. They may be divided into three groups: 1 31 I , 1 37 C s, 1 34 C s, 9 0 S r and 8 9 S r fission fragments, isotopes of noble gases krypton and xenon and other radionuclides; corrosion originated radionuclides: 6 0 C o, 1 10m A g, 5 4 M n, 5 l C r and others; activation products of the heat-transfer agent itself. It should be noted that the amount of radioactive materials released in the environment by the ANPP during the whole period of its operation was much lower than the admissible quantities specified in the corresponding legal documents (RSN, NPPSP) acting in Armenia, which are practically identical to the internationally accepted norms. The amounts of releases and their radionuclides composition for the ANPP are given

  7. Consideration for modelling studies of migration of accidentally released radionuclides in a river watershed

    International Nuclear Information System (INIS)

    Matsunaga, Takeshi; Tsuduki, Katsunori; Yanase, Nobuyuki; Hanzawa, Yukiko; Ueno, Takashi

    2004-01-01

    Concerning radionuclides that might be released in an event of an accident from a nuclear facility, much attention has been paid to the migration pathways including the atmospheric deposition and subsequent inflow to surface water bodies since the Chernobyl nuclear accident in 1986. In European countries, computer-coded systems for predicting the migration including those pathways and providing scientific supports for decision makers to manage the contamination have been developed. This report is a summary of presentations and discussion made at the occasion of the visit of Dr. Monte in order to have directions related to the current subject of research, development of a mathematical model of the behavior of radionuclides in a river watershed. Those presentations and discussions were made at JAERI and also at prominent universities and institutes of Japan involved in this study field. As a result of these discussions, distinct advantages and key issues in use of a mathematical model for prediction of the migration of radionuclides in a river watershed have been identified and analyzed. It was confirmed that the use of mathematical modeling has distinct advantages. Re-arrangement of the existing experimental knowledge on the environment in an ordered way according to a theory (a mathematical model) will lead to a new angle to consider a problem in that environment, despite several gaps in the data array. A model to assess the radionuclide behaviour in contaminated aquatic ecosystems is a basis of decision analysis tools for helping decision-makers to select the most appropriate intervention strategies for the ecosystems. Practical use of a mathematical model and continuous effort in its validation were recognized as crucial. (author)

  8. Investigation of radionuclide release from Solid Waste Disposal Area 3, Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Stueber, A.M.; Webster, D.A.; Munro, I.L.; Farrow, N.D.; Scott, T.G.

    1981-08-01

    Radionuclide release from Solid Waste Disposal Area (SWDA) 3 has been studied through the analysis of surface and ground waters from the local drainage areas. SWDA 3 is located in the Northwest Tributary drainage basin, a part of the White Oak Creek drainage; 90 Sr is the only radionuclide being discharged in solution in the main stream. Water-level measurements in wells around SWDA 3 suggest the presence of a ground-water divide beneath the southwestern end of the disposal area. Ground water below this area may be moving southwestward toward the Raccoon Creek drainage system. Strontium-90 activity has been detected in this watershed, discharging from a seep adjacent to a Raccoon Creek tributary stream about 640 m southwest of SWDA 3. It appears that 90 Sr is moving through ground-water flow to the northeast and to the southwest of SWDA 3 and that this direction of movement is related to bedrock structure. The trend of a line connecting the two seeps passes through the disposal area and is parallel to bedrock strike. Information from core-hole logs and televiewer logs suggests that 90 Sr in ground water may be moving through solution channels near the contact between units F and G of the Chickamauga Limestone. The apparent extent of migration of 90 Sr in bedrock has implications regarding potential underground radionuclide movement in Melton Valley

  9. Radionuclide solubility control by solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, F.; Klinkenberg, M.; Rozov, K.; Bosbach, D. [Forschungszentrum Juelich GmbH (Germany). Inst. of Energy and Climate Research - Nuclear Waste Management and Reactor Safety (IEK-6); Vinograd, V. [Frankfurt Univ. (Germany). Inst. of Geosciences

    2015-07-01

    The migration of radionuclides in the geosphere is to a large extend controlled by sorption processes onto minerals and colloids. On a molecular level, sorption phenomena involve surface complexation, ion exchange as well as solid solution formation. The formation of solid solutions leads to the structural incorporation of radionuclides in a host structure. Such solid solutions are ubiquitous in natural systems - most minerals in nature are atomistic mixtures of elements rather than pure compounds because their formation leads to a thermodynamically more stable situation compared to the formation of pure compounds. However, due to a lack of reliable data for the expected scenario at close-to equilibrium conditions, solid solution systems have so far not been considered in long-term safety assessments for nuclear waste repositories. In recent years, various solid-solution aqueous solution systems have been studied. Here we present state-of-the art results regarding the formation of (Ra,Ba)SO{sub 4} solid solutions. In some scenarios describing a waste repository system for spent nuclear fuel in crystalline rocks {sup 226}Ra dominates the radiological impact to the environment associated with the potential release of radionuclides from the repository in the future. The solubility of Ra in equilibrium with (Ra,Ba)SO{sub 4} is much lower than the one calculated with RaSO{sub 4} as solubility limiting phase. Especially, the available literature data for the interaction parameter W{sub BaRa}, which describes the non-ideality of the solid solution, vary by about one order of magnitude (Zhu, 2004; Curti et al., 2010). The final {sup 226}Ra concentration in this system is extremely sensitive to the amount of barite, the difference in the solubility products of the end-member phases, and the degree of non-ideality of the solid solution phase. Here, we have enhanced the fundamental understanding regarding (1) the thermodynamics of (Ra,Ba)SO{sub 4} solid solutions and (2) the

  10. Sorption and desorption reactions of radionuclides with a crushed basalt-bentonite packing material

    International Nuclear Information System (INIS)

    Barney, G.S.; Lane, D.L.; Allen, C.C.; Jones, T.E.

    1985-04-01

    Current design of waste packages for disposal of high-level radioactive wastes in underground basalt formations includes a layer of packing material that surrounds the waste container. One of the functions of this material is to limit the release of radionuclides from a breached container into groundwater by providing a low hydraulic conductivity zone and by sorbing dissolved radionuclides. The objective of this study was to assess the radionuclide sorption capability of a proposed packing material composed of 25% sodium bentonite and 75% crushed basalt (by weight). Sorption and desorption reactions of several important waste radioelements (neptunium, uranium, plutonium, technetium, selenium, and radium) were investigated in the absence of air at 90 0 C. Uranium and neptunium were sorbed by slow reactions that follow first-order kinetics. The reaction rates are probably controlled by reduction of weakly sorbed uranium(VI) and neptunium(V) by ferrous iron in the crushed basalt component. Technetium(VII) was not reduced or sorbed under these conditions. Freundlich sorption and desorption isotherms for a given radionuclide were non-singular and show a strong tendency for sorption hysteresis. Applying the isotherm data to a one-dimensional transport model indicated that hysteretic sorption on the packing material provides an important safety factor in controlling releases of some radionuclides

  11. Retrospective estimation of middle irradiation doses for population of south Ukraine from radionuclides of Chernobyl accidental release

    International Nuclear Information System (INIS)

    Grigor'jeva, L.Yi.; Grigor'jev, K.V.

    2011-01-01

    The results of retrospective definition of the radiation load to the population of south Ukraine the under abnormal condition Chernobyl release of radionuclide, executed from data of aerophare, spectrometry and dosimetric researches on territory Nikolaev, Odessa, Kirovograd areas and Autonomous Republic of Crimea, conducted by the Nikolaev research laboratory ''Larani'' in 1986 and in subsequent years are presented in the article.

  12. Report of the consultant's meeting on monitoring accidentally released radionuclides in the environment

    International Nuclear Information System (INIS)

    2001-01-01

    At an earlier Research Co-ordination Meeting (12-16 August 1991, VIC, Vienna) for the IAEA Programme on 'Rapid Instrumental and Separation Methods for Monitoring Radionuclides in Food and Environmental Samples', it was recognized that a network of analytical laboratories with specially qualified scientists is needed which will provide a timely coordinated response to any future requests for assistance from Member States. The experience gained from the International Chernobyl Project revealed that there is a need for such a closely linked group when the Member State lacks sufficient technical resource to independently perform an assessment of environmental contamination following an accidental release of radioactivity. The existence of such a network of laboratories would help to assure responsible government representatives and the general public that the Agency has additional available resources including specialized experts to perform assessments on which to base required actions for many accident scenarios and their radiological consequences. The purpose of the present Consultants' Meeting is to discuss the organization and scope of the proposed network of analytical laboratories. The Consultants should discuss the matrices and nuclides of interest at various time frames of an accidental release of radioactivity. It is also intended that the Consultants should discuss the laboratories from their experience which would have the specialized expertise needed, in both terrestrial and aquatic sample collection and analysis. Finally, it is intended that the Consultants should discuss whether it would be desirable for the Agency to produce a technical document based on the achievements of the Agency programme on 'Rapid Instrumental and Separation Methods for Monitoring Radionuclides in Food and Environmental Samples'. A Guide Book was considered essential by the participants of this Co-ordinated Research Programme because it would be a succinct form and on a common

  13. Idaho radionuclide exposure study: Literature review

    International Nuclear Information System (INIS)

    Baker, E.G.; Freeman, H.D.; Hartley, J.N.

    1987-10-01

    Phosphate ores contain elevated levels of natural radioactivity, some of which is released to the environment during processing or use of solid byproducts. The effect of radionuclides from Idaho phosphate processing operations on the local communities has been the subject of much research and study. The literature is reviewed in this report. Two primary radionuclide pathways to the environment have been studied in detail: (1) airborne release of volatile radionuclides, primarily 210 Po, from calciner stacks at the two elemental phosphorus plants; and (2) use of byproduct slag as an aggregate for construction in Soda Springs and Pocatello. Despite the research, there is still no clear understanding of the population dose from radionuclide emissions, effluents, and solid wastes from phosphate processing plants. Two other potential radionuclide pathways to the environment have been identified: radon exhalation from phosphogypsum and ore piles and contamination of surface and ground waters. Recommendations on further study needed to develop a data base for a complete risk assssment are given in the report

  14. Natural and Synthetic Barriers to Immobilize Radionuclides

    International Nuclear Information System (INIS)

    Um, W.

    2011-01-01

    The experiments of weathering of glass waste form and the reacted sediments with simulated glass leachates show that radionuclide sequestration can be significantly enhanced by promoting the formation of secondary precipitates. In addition, synthetic phosphate-bearing nanoporous material exhibits high stability at temperature and has a very high K d value for U(VI) removal. Both natural and synthetic barrier materials can be used as additional efficient adsorbents for retarding transport of radionuclides for various contaminated waste streams and waste forms present at U. S. Department of Energy clean-up sites and the proposed geologic radioactive waste disposal facility. In the radioactive waste repository facility, natural or synthetic materials are planned to be used as a barrier material to immobilize and retard radionuclide release. The getter material can be used to selectively scavenge the radionuclide of interest from a liquid waste stream and subsequently incorporate the loaded getters in a cementitious or various monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides form monolithic waste forms by being emplaced as a backfill barrier material around the wastes or waste form to minimize the potential around the wastes or waste form to minimize the potential hazard of leached radioactive wastes. The barrier material should be highly efficient to sequester radionuclides and possess physical and chemical stability for long-term exposure to severe weathering conditions. Because potential leaching of radionuclides depends on various environmental and weathering conditions of the near-field repository, the barrier materials must be durable and not disintegrate under a range of moisture, temperature, pressure, radiation, Eh, ph. and

  15. Spectrometric control of radionuclides production parameters

    International Nuclear Information System (INIS)

    Zhuk, I.; Potarenko, A.; Yarochevich, O.; Hluboky, N.; Kerko, P.; Bogdanov, V.; Dyatel, N.

    2006-01-01

    Full text: A radioactive preparations and sources are widely used all over the world for scientific, industrial and medical purposes. These preparations in Belarus are planned to produce by the Joint Belarussian-Russian Closed Joint Stock Company 'Isotope technologies' (CJSC IT). The company was created in 1998 by two leading scientific centers-SSI 'Joint Institute of Power and Nuclear Research-Sosny' the National Academy of Sciences of Belarus and the State Center of Science of the Russian Federation 'Scientific research institute of nuclear reactors'. One of the mainstream directions in CJSC IT activities is production of radioactive preparations for the industrial and scientific application (such as 133 Ba, 109 Cd, 63 Ni, 60 Co) and for the medical purposes (such as 19 '2Ir, 60 Co). All radioactive preparations have a good export potential and adequate to modern technical and consumer requirements. X-γ spectrometric analysis of considered radioactive sources is one of the basic methods for quality control of radioactive sources. At present, we are developing x-γ spectrometric support of purification process from contaminating radionuclides of 109 Cd -γ preparation and 63 Ni - β preparation. Work on x-γ spectrometric quality control of 133 Ba preparation is carried out. The description of the used equipment is given. Techniques of contaminating radionuclides determination (contents ∼10 - '6 from activity of the basic radionuclide) are presented. Problems of the choice of geometry of measurements of sources with activity about 10 7 -10 9 Bq and possible sources of errors are discussed. (author)

  16. Scenarios for potential radionuclide release from marine reactors dumped in the Kara Sea

    International Nuclear Information System (INIS)

    Lynn, N.; Mount, M.; Gussgard, K.

    1995-01-01

    The largest inventory of radioactive materials dumped in the Kara Sea by the former Soviet Union comes from the spent nuclear fuel (SNF) of seven marine reactors, the current (1994) inventory of which makes a total of approximately 4.7x10 15 Bq. In progressing its work for the International Arctic Seas Assessment Project, under the auspices of the International Atomic Energy Agency, the Source Term Working Group has analysed the Source Term and subsequently developed a number of model scenarios for the potential release patterns of radionuclides into the Kara Sea from the SNF and activated components dumped within the marine reactors.These models are based on the present and future conditions of the barrier materials and their configuration within the dumped objects. They account for progressive corrosion of the outer and inner steel barriers, breakdown of the organic fillers, and degradation and leaching from the SNFs. Annual release rates are predicted to four thousand years into the future. 5 refs., 1 fig., 1 tab

  17. Control decisions for 3H, 14C, 85Kr, and 129I released from the commercial fuel cycle

    International Nuclear Information System (INIS)

    Thomas, T.R.; Brown, R.A.

    1985-01-01

    The effects of complete release of 3 H, 14 C, 85 Kr and 129 I from operating a 400-GWe fuel cycle for 100 years are shown. The postulated accrued health effects (HE) from 14 C and 129 I appear large; however, these numbers are insignificant when compared to the 176 billion cancer deaths that would occur from all causes in the 10,000-year reference period. The percent increase in global cancer deaths would be no greater than 5 x 10 -5 % for each of the radionuclides. Based on the 1980 inventory of each radionuclide in the environment, complete release for 100 years from a 400-GWe fuel cycle would not increase the 3 H or 14 C inventories, however, large increases in 85 Kr and 129 I inventories would occur. The effects, besides dose impacts, of large increases in inventory are unknown and serve only as warning flags that should be taken into consideration. Only 129 I releases from a fuel reprocessing plant would exceed the allowable maximum exposed individual dose limit and 85 Kr and 129 I would exceed the allowable release limit. The effects of controlled releases from commercial fuel reprocessing plants serving a 400-GWe fuel cycle for 100 years are also shown

  18. Sensitivity of the engineered barrier system (EBS) release rate to alternative conceptual models of advective release from waste packages under dripping fractures

    International Nuclear Information System (INIS)

    Lee, J.H.; Atkins, J.E.; McNeish, J.A.; Vallikat, V.

    1996-01-01

    Simulations were conducted to analyze the sensitivity of the engineered barrier system (EBS) release rate to alternative conceptual models of the advective release from waste packages under dripping fractures. The first conceptual model assumed that dripping water directly contacts the waste form inside the 'failed' waste package, and radionuclides are released from the EBS by advection. The second conceptual model assumed that dripping water is diverted around the 'failed' waste package (because of the presence of corrosion products plugging the perforations) and dripping water is prevented from directly contacting the waste form. In the second model, radionuclides were assumed to transport through the perforations by diffusion, and, once outside the waste package, to be released from the EBS by advection. The second model was to incorporate more realism into the EBS release calculations. For the case with the second EBS release model, most radionuclides had significantly lower peak EBS release rates (from at least one to several orders of magnitude) than with the first EBS release model. The impacts of the alternative EBS release models were greater for the radionuclides with a low solubility (or solubility-limited radionuclides) than for the radionuclides with a high solubility (or waste form dissolution-limited radionuclides). The analyses indicated that the EBS release model representing advection through a 'failed' waste package (the first EBS release model) may be too conservative in predicting the EBS performance. One major implication from this sensitivity study was that a 'failed' waste package container with multiple perforations may still be able to perform effectively as an important barrier to radionuclide release. (author)

  19. BLT-EC (Breach, Leach Transport, and Equilibrium Chemistry), a finite-element model for assessing the release of radionuclides from low-level waste disposal units: Background, theory, and model description

    International Nuclear Information System (INIS)

    MacKinnon, R.J.; Sullivan, T.M.; Simonson, S.A.; Suen, C.J.

    1995-08-01

    Performance assessment models typically account for the processes of sorption and dissolution-precipitation by using an empirical distribution coefficient, commonly referred to as K d that combines the effects of all chemical reactions between solid and aqueous phases. In recent years, however, there has been an increasing awareness that performance assessments based solely on empirically based K d models may be incomplete, particularly for applications involving radionuclides having sorption and solubility properties that are sensitive to variations in the in-situ chemical environment. To accommodate variations in the in-situ chemical environment, and to assess its impact on radionuclide mobility, it is necessary to model radionuclide release, transport, and chemical processes in a coupled fashion. This modeling has been done and incorporated into the two-dimensional, finite-element, computer code BLT-EC (Breach, Leach, Transport, Equilibrium Chemistry). BLT-EC is capable of predicting container degradation, waste-form leaching, and advective-dispersive, multispecies, solute transport. BLT-EC accounts for retardation directly by modeling the chemical processes of complexation, sorption, dissolution-precipitation, ion-exchange, and oxidation-reduction reactions. In this report we: (1) present a detailed description of the various physical and chemical processes that control the release and migration of radionuclides from shallow land LLW disposal facilities; (2) formulate the mathematical models that represent these processes; (3) outline how these models are incorporated and implemented in BLT-EC; and (4) demonstrate the application of BLT-EC on a set of example problems

  20. SCATTER: Source and Transport of Emplaced Radionuclides: Code documentation

    International Nuclear Information System (INIS)

    Longsine, D.E.

    1987-03-01

    SCATTER simulated several processes leading to the release of radionuclides to the site subsystem and then simulates transport via the groundwater of the released radionuclides to the biosphere. The processes accounted for to quantify release rates to a ground-water migration path include radioactive decay and production, leaching, solubilities, and the mixing of particles with incoming uncontaminated fluid. Several decay chains of arbitrary length can be considered simultaneously. The release rates then serve as source rates to a numerical technique which solves convective-dispersive transport for each decay chain. The decay chains are allowed to have branches and each member can have a different radioactive factor. Results are cast as radionuclide discharge rates to the accessible environment

  1. Retrospective estimation of middle irraiation doses for population of south Ukraine from radionuclides of Chernobyl accidental release

    Directory of Open Access Journals (Sweden)

    L. I. Grygorieva

    2011-09-01

    Full Text Available The results of retrospective definition of the radiation load to the population of south Ukraine the under abnormal condition Chernobyl release of radionuclide, executed from data of aerophare, spectrometry and dosimetric researches on territory Nikolaev, Odessa, Kirovograd areas and Autonomous Republic of Crimea, conducted by the Nikolaev research laboratory “Larani” in 1986 and in subsequent years are presented in the article.

  2. Assessment of Radionuclides in the Savannah River Site Environment Summary

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.

    1999-01-26

    This document summarizes the impact of radionuclide releases from Savannah River Site (SRS) facilities from 1954 through 1996. The radionuclides reported here are those whose release resulted in the highest dose to people living near SRS.

  3. The influence of site on the impact of radionuclides released into the marine environment

    International Nuclear Information System (INIS)

    Lochard, J.; Maccia, C.; Pages, P.

    1981-01-01

    The potential health impact of releases into the sea from a nuclear facility in normal operation is evaluated in two stages. First the concentration in sea water is determined by means of an area dispersion model which makes it possible to calculate the contamination of marine products (fish, crustaceans and molluscs) in the various areas. Then allowance is made for exchanges between the fishing zones and the regions where the products are consumed in order to estimate the collective radiological detriment on the regional level. The dispersion model was first applied to releases of 137 Cs which occurred during the 1969-1976 period in areas of the eastern English Channel and the eastern Irish Sea. Good agreement is observed with the measurements performed in 1976. The significance of site parameters is then demonstrated by comparing the evolution of concentrations after unit releases of 137 Cs and 239 Pu spread over one year. Depending on the radionuclide and the area where the release takes place, preponderant dilution effects (exchanges between areas) and/or sedimentation effects are observed. After presenting the method of calculating ingested activities, the main results for France are given, showing the impact of 137 Cs releases from a nuclear power station using Pressurized Water Reactors (4x1300 MW(e)) over a period of one year. (author)

  4. Effect of ionizing radiation on radionuclide speciation: Preliminary results from site-specific experiments in a basaltic system

    International Nuclear Information System (INIS)

    Reed, D.T.; Burnell, J.R.

    1986-01-01

    Rockwell Hanford Operations, under contract to the Department of Energy, is investigating the suitability of the Hanford site in the state of Washington as a high level nuclear waste repository. An important consideration in these investigations is the effect of ionizing radiation on the speciation of radionuclides in the groundwater after the high-level-waste container has been breached and there is direct contact between the groundwater and the waste form (controlled released period). The effect of ionizing radiation on radionuclide speciation depends on the radiation environment and site-specific chemistry near the waste container. With respect to these two aspects, the following results will be presented: a definition of the radiation environment during the controlled release period; preliminary site-specific experimental results: (1) basaltic systems spiked with radionuclides; (2) spent fuel-groundwater-basalt experiments

  5. Testing the behaviour of different kinetic models for uptake/release of radionuclides between water and sediments when implemented in a marine dispersion model

    International Nuclear Information System (INIS)

    Perianez, R.

    2004-01-01

    Three kinetic models for adsorption/release of 137 Cs between water and sediments have been tested when they are included in a previously validated dispersion model of the English Channel. Radionuclides are released to the Channel from La Hague nuclear fuel reprocessing plant (France). The kinetic models are a 1-step model consisting of a single reversible reaction, a 2-step model consisting of two consecutive reversible reactions and an irreversible model consisting of three parallel reactions: two reversible and one irreversible. The models have been tested under three typical situations that correspond to the source terms that can generally be found: instantaneous release, continuous release and redissolution of radionuclides from contaminated sediments. Differences between the models become more evident when contact times between water and sediments are larger (continuous release) and in the case of redissolution from sediments. Time scales for the redissolution process are rather different between the three models. The 1-step model produces a redissolution that is too fast when compared with experimental evidence. The irreversible model requires that saturation effects of the irreversible phase are included. Probably, the 2-step model represents the best compromise between ease and level of detail of the description of sorption/release processes

  6. Biosphere assessment due to radionuclide release in waste disposal repository through food chain pathways

    International Nuclear Information System (INIS)

    Ko, H. S.; Kang, C. S.

    2000-01-01

    The long-term safety of radioactive waste disposal is assessed by the consequence analysis of radionuclides release, of which the final step is carried out by the biosphere assessment. the radiation dose is calculated from the food chain modeling which especially necessitates site-specific input database and exposure pathways. A biosphere model in consideration of new exposure pathways has been analyzed, and a program for food chain calculation has been developed. The up-to-data input data are reflected and the new exposure pathways are considered in the program, so the code shows more realistic and reliable results

  7. Modelling the transport of radionuclides released in the Ilha Grande bay (Brazil) after a Large Break Loca ion the primary system of a PWR

    International Nuclear Information System (INIS)

    Aguiar, Andre Silva de; Simoes Filho, Francisco Fernando Lamego; Soares, Abner Duarte; Lapa, Celso Marcelo Franklin

    2011-01-01

    It was postulated, in the cooling system of the core, a LOCA, where 431 m 3 of soda almost instantaneously was lost. This inventory contained 1.87x10 10 Bq/m 3 of tritium, 2.22x10 7 Bq/m 3 of cobalt,3.48x10 8 Bq/m 3 of cesium and 3.44x10 10 Bq/m 3 of iodine and was released in liquid form near the Itaorna cove, Angra dos Reis - RJ. Applying the model in the proposed scenario (Angra 1 and 2 in operation and Angra 3 progressively reducing the capture and discharge after the accident), the simulated dilution of the specific activity of radionuclide spots, reached values much lower than report levels for seawater (1,1x10 6 Bq/m 3 , 1,11x10 4 Bq/m 3 and 1,85x10 3 Bq/m 3 ) after 22 hours, respectively for 3 H, 60 Co, 131 I and 137 Cs. From the standpoint of public exposure to radionuclide dispersion, the results of activity concentration obtained by the model suggest that the observed radiological impact is negligible. Based on these findings, we conclude that there would be no radiological impact related to a further release of controlled effluent discharges into Itaorna cove. (author)

  8. Simplified analytical model to simulate radionuclide release from radioactive waste trenches; Modelo simplificado para simulacao da liberacao de radionuclideos de repositorios de rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Bernardete Lemes Vieira de

    2001-07-01

    In order to evaluate postclosure off-site doses from low-level radioactive waste disposal facilities, a computer code was developed to simulate the radionuclide released from waste form, transport through vadose zone and transport in the saturated zone. This paper describes the methodology used to model these process. The radionuclide released from the waste is calculated using a model based on first order kinetics and the transport through porous media was determined using semi-analytical solution of the mass transport equation, considering the limiting case of unidirectional convective transport with three-dimensional dispersion in an isotropic medium. The results obtained in this work were compared with other codes, showing good agreement. (author)

  9. Radionuclide release, transport, and consequence modeling for WIPP: a report of a workshop held on September 16-17, 1981

    International Nuclear Information System (INIS)

    1982-02-01

    The purpose of this workshop was to discuss potential mechanisms for release of radionuclides from the WIPP repository years after waste emplacement and termination of institutional controls, and the resultant radiological consequences. Opportunity was also provided for the exchange of information on meaningful release and transport models, and the availability, reliability and significance of data for the parameters applicable to those models. Other than those scenarios provided in draft by the Environmental Evaluation Group (EEG) (Appendix II), there were no new breach scenarios postulated. Also there were no major objections posed to the EEG proposals or the approaches taken in these drafts. Although there were no formal conclusions highlighted by the Conference, the EEG has concluded that the statements below provide a summary of EEG's views concerning the topics covered. These views are based upon the discussions at the Conference, the subsequent comments of the conferees, the information provided in the preceding EEG sponsored geological meeting and field trip, and the information contained in the EEG draft reports

  10. Effect of pH on the release of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resins collected from operating nuclear power stations

    International Nuclear Information System (INIS)

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.

    1991-06-01

    Data are presented on the physical stability and leachability of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small-scale waste--form specimens collected during solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station were leach-tested and subjected to compressive strength testing in accordance with the Nuclear Regulatory Commission's ''Technical Position on Waste Form'' (Revision 1). Samples of untreated resin waste collected from each solidification vessel before the solidification process were analyzed for concentrations of radionuclides, selected transition metals, and chelating agents to determine the quantities of these chemicals in the waste-form specimens. The chelating agents included oxalic, citric, and picolinic acids. In order to determine the effect of leachant chemical composition and pH on the stability and leachability of the waste forms, waste-form specimens were leached in various leachants. Results of this study indicate that differences in pH do not affect releases from cement-solidified decontamination ion-exchange resin waste forms, but that differences in leachant chemistry and the presence of chelating agents may affect the releases of radionuclides and chelating agents. Also, this study indicates that the cumulative releases of radionuclides and chelating agents are similar for waste- form specimens that decomposed and those that retained their general physical form. 36 refs., 60 figs., 28 tabs

  11. Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem

    International Nuclear Information System (INIS)

    Smith, G.M.; Smith, K.L.; Kowe, R.; Pérez-Sánchez, D.; Thorne, M.; Thiry, Y.; Read, D.; Molinero, J.

    2014-01-01

    Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, (www.bioprota.org). - Highlights: • Geological

  12. Sensitivity of the engineered barrier system (EBS) release rate to alternative conceptual models of advective release from waste packages under dripping fractures

    International Nuclear Information System (INIS)

    Lee, J.H.; Atkins, J.E.; McNeish, J.A.; Vallikat, V.

    1996-01-01

    The first model assumed that dripping water directly contacts the waste form inside the ''failed'' waste package and radionuclides are released from the EBS by advection. The second model assumed that dripping water is diverted around the package (because of corrosion products plugging the perforations), thereby being prevented from directly contacting the waste form. In the second model, radionuclides were assumed to diffuse through the perforations, and, once outside the waste package, to be released from the EBS by advection. For the case with the second EBS release model, most radionuclides had lower peak EBS release rates than with the first model. Impacts of the alternative EBS release models were greater for the radionuclides with low solubility. The analysis indicated that the EBS release model representing advection through a ''failed'' waste package (the first model) may be too conservative; thus a ''failed'' waste package container with multiple perforations may still be an important barrier to radionuclide release

  13. Outline of UNSCEAR 2013 report (1). Radionuclide releases, dispersion and deposition

    International Nuclear Information System (INIS)

    Nagai, Haruyasu; Kurihara, Osamu

    2014-01-01

    The general assembly of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was held in May, 2013 and the influence of the TEPCO Fukushima Daiichi nuclear power station accident on the environment and the human body, which has been analyzed and discussed by many specialists, was reported. The detailed contents of the influence were published in April, 2014 as the UNSCEAR 2013 Report (Vol. I: Report of the UNSCEAR to the General Assembly; Scientific Annex A: Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami and Vol. II: Scientific Findings on Effects of Radiation Exposure of Children; Scientific Annex B: Effects of radiation exposure of children). In the present paper, the outlines of the Scientific Annex A and the chapter III (Radionuclide releases, dispersion and deposition) in it are described. (K. Kato)

  14. Release of patients after radionuclide therapy. With contributions from the [International Commission on Radiological Protection] ICRP

    International Nuclear Information System (INIS)

    2009-01-01

    The use of unsealed radiopharmaceuticals for treatment of disease is common practice worldwide. This approach was widely employed some years ago and, following a decline, there has recently been a resurgence of interest in it. The combination of newly accessible radionuclides, improved labelling technology and developments in biotechnology has resulted in more enthusiasm and a wider range of applications for this form of therapy. Radionuclide treatments are performed with either the patient admitted to hospital or as an outpatient only. The criteria to determine which approach is best vary considerably, and are not always closely linked with the well established standards of radiation protection practice. Safety issues for the patient, their family, associated carers, staff and the general public arise with either approach. The potential risks are from both external irradiation and contamination. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) specify the dose constraints and limits for all of these groups, and their more general provisions with respect to the as low as reasonably achievable principle and justification also apply. One way of managing exposures of the various groups is to control when patients are released from hospital. While they are in hospital, it is relatively easy to control exposure. Once they have returned to their family in the community, they must be advised on how to restrict the exposure of those people that they will come into contact with. Until recently, the International Commission on Radiological Protection (ICRP) did not provide specific advice in this area, and relied on the application of dose limits and constraints. However, regulators in some countries took a prescriptive approach, often using estimates of retained activity as a release criterion. These only loosely relate to dose limits. This publication attempts to bring newly available advice

  15. Global collective dose commitments from release of long-lived radionuclides. Differential cost-benefit considerations

    International Nuclear Information System (INIS)

    Gjoerup, H.L.

    1977-01-01

    The concept of global collective dose commitment as a measure of total detriment from the release of radioactivity to the environment is outlined. Estimates are given of global collective dose commitments resulting from the release of 14 C and uranium daughter products from the nuclear fuel cycle. Comparisons are made with similar estimates of global collective dose commitments resulting from the use of fossil fuels and certain fertilizers due to their content of uranium and its daughter products. In the case of long-lived radionuclides that remain in circulation in the biosphere, it is shown that the use of global collective dose commitments in differential cost-benefit analysis can lead to questionable results. In differential cost-benefit analysis it is suggested that population exposures should not simply be integrated irrespective of their time of occurrence, but that a certain discount rate should be applied for future doses. This suggestion is examined. (author)

  16. Joint release rate estimation and measurement-by-measurement model correction for atmospheric radionuclide emission in nuclear accidents: An application to wind tunnel experiments.

    Science.gov (United States)

    Li, Xinpeng; Li, Hong; Liu, Yun; Xiong, Wei; Fang, Sheng

    2018-03-05

    The release rate of atmospheric radionuclide emissions is a critical factor in the emergency response to nuclear accidents. However, there are unavoidable biases in radionuclide transport models, leading to inaccurate estimates. In this study, a method that simultaneously corrects these biases and estimates the release rate is developed. Our approach provides a more complete measurement-by-measurement correction of the biases with a coefficient matrix that considers both deterministic and stochastic deviations. This matrix and the release rate are jointly solved by the alternating minimization algorithm. The proposed method is generic because it does not rely on specific features of transport models or scenarios. It is validated against wind tunnel experiments that simulate accidental releases in a heterogonous and densely built nuclear power plant site. The sensitivities to the position, number, and quality of measurements and extendibility of the method are also investigated. The results demonstrate that this method effectively corrects the model biases, and therefore outperforms Tikhonov's method in both release rate estimation and model prediction. The proposed approach is robust to uncertainties and extendible with various center estimators, thus providing a flexible framework for robust source inversion in real accidents, even if large uncertainties exist in multiple factors. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. A quality control exercise of radionuclide calibrators among Belgian hospitals

    International Nuclear Information System (INIS)

    Reher, D.F.G.; Merlo, P.

    1990-01-01

    On the initiative of the Belgian Association of Hospital Physicists, eleven Belgian hospitals participated in a quality control of radionuclide calibrators conducted in collaboration with the Central Bureau for Nuclear Measurements of the Commission of the European Communities. For practical reasons the nuclide 57 Co was chosen. The results from 20 different radionuclide calibrators show a fair agreement with a similar comparison carried out in 1980 in the UK. (orig.)

  18. Wind rose and Radionuclide Dispersion Modelling for Nuclear Malaysia Research Reactor

    International Nuclear Information System (INIS)

    Mohd Nahar Othman

    2015-01-01

    After the incident of radioactive gasses released to the environment because of unusual earthquake and tsunamis happen in Fukushima, Japan. The problem of release of radiological radionuclide became deep concern and serious problem to the world community. The incident course almost all nuclear power plant in Japan cannot operate because opposition from local people. From this point of view Malaysian Nuclear agency don't left behind in doing it research in release of radionuclide from it research reactor, in the meantime new wind rose data had been collected from 2013 to 2014. This paper will present the new radionuclide release including the new dispersion modelling that had been developed. (author)

  19. Radionuclide transport in the repository near-field and far-field

    International Nuclear Information System (INIS)

    Poteri, A.; Nordman, H.; Pulkkanen, V.-M.; Smith, P.

    2014-01-01

    This report is a background report of the TURVA-2012 safety case report 'Assessment of Radionuclide Release Scenarios for the Repository System'. This report gives a comprehensive account of the modelling of radionuclide release from a defective canister and the subsequent migration to the surface groundwater system. The focus of this report is in the radionuclide migration both in the repository near-field and in the repository far-field. Radionuclide releases from the canister and migration through the repository near-field and far-field have also been analysed in the probabilistic sensitivity analysis based on the Monte Carlo simulation method. Those simulations are discussed in a separate report by Cormenzana. Calculation cases are derived from three different types of scenarios: (i) The base scenario that assumes a single initially defective canister located in a cautiously selected canister position, i.e. selecting the failed canister location such that radionuclide release and transport properties are conservative compared to the statistics over all canister locations. Migration processes and parameter values follow the most likely lines of evolution. Repository safety functions are assumed to perform according to the design basis. Calculation cases defined in the Assessment of Radionuclide Release Scenarios report are also supplemented by additional calculation cases that are aimed to study variability between different DFN realisations (additional BS-ALL cases), longitudinal dispersion (BS-RC-ld cases) and alternative realisations of the transport classes along the release paths (BS-RC-tc cases), (ii) Variant scenarios that study declined performance of the repository safety functions. These include enhanced corrosion failure and degradation of the buffer under variant geochemical conditions (iii) Disturbance scenarios that analyse influences of unlikely events on the radionuclide release and migration. Analysis of the variant and disturbance scenarios

  20. The use of 59Ni, 99Tc, and 236U to monitor the release of radionuclides from objects containing spent nuclear fuel dumped in the Kara Sea

    International Nuclear Information System (INIS)

    Mount, M.E.; Layton, D.W.; Hamilton, T.F.; Lynn, M.

    1999-01-01

    Between 1965 and 1981, five objects and six naval reactor pressure vessels (RPVs) from four former Soviet Union submarines and a special container from the icebreaker Lenin, all containing damaged spent nuclear fuel (SNF) were dumped in a variety of containments, at four sites in the Kara Sea. The International Atomic Energy Agency initiated the International Arctic Seas Assessment Project (IASAP) to study the possible health and environmental effects from disposal of these objects. One outcome of the IASAP was an estimation of the radionuclide inventory and their release rates from these objects. A follow-on concern is the ability to detect the radionuclides released into the water column. The work reported here is the feasibility of using the long-lived radionuclides 59 Ni, 99 Tc, and 236 U encased within these objects, to monitor the breakdown of the containments due to corrosion

  1. Transfer of radionuclides to man through environmental pathways

    International Nuclear Information System (INIS)

    Mitchell, N.T.

    1974-01-01

    The most widely accepted method in current use for the evaluation of environmental impact from releases of radioactivity that may cause human radiation exposure used an environmental pathway model. The more important aspects of the model involve the use of critical pathway techniques to set controls on the releases of radioactive material to the environment and to assess the human radiation exposure arising as a consequence. The basic concepts of the environmental pathway model and its application are discussed. The model depends on achieving an understanding of radionuclide behavior in the environment, from the moment of release up to the time when contamination results in radiation exposure to the public. Exposure may be as a result of contaminated material entering the body-as air, water or a foodstuff; alternatively, it may be due to radiation whose source is external to the body. For each of these types of exposure pathway the sequence of events can be divided up into a number of compartments, between which transfer takes place. Transfer along the pathway is a dynamic process and can be described mathematically in terms of transfer functions between interacting compartments. Alternatively, for the situation of a regular discharge resulting in a steady-state condition the relationship between compartments can be expressed as a 'concentration factor'. The derivation of both of these terms is described and some aspects of their use are discussed. The paper then goes on to discuss the types of environmental pathway that are encountered as a result of release of radionuclides to the atmospheric and aquatic environments. Disposal to the ground is regarded as a special case of release to the aquatic environment. Some ot the literature on the subject is reviewed in discussingthe better known pathways showing what, to date, have been the most important mechanisms of transfer of radionuclides to man. (author)

  2. Binding and release of artificial radionuclides in sediments

    International Nuclear Information System (INIS)

    Foerstner, U.; Schoer, J.

    1980-01-01

    Artificial radionuclides in aquatic systems are generally associated with more labile solid phases than are their stable counterparts. This implies that special attention must be paid to the possible effects on the biological uptake of artificial isotopes from contamined dredged materials following deposition or land application. An estimation of possible effects could be made from chemical extraction experiments similar to those already applied to stable heavy metal isotopes. Within the aquatic system the changes of the physico-chemical conditions, such as pH-values, oxygen content, salinity, and the concentration of complexing organic substances, may effect a partial remobilization of artificial radionuclides from the solids, which occurs more readily than with the respective stable isotopes. (orig.) [de

  3. Releases of radioactivity at the Savannah River Plant, 1954-1980

    Energy Technology Data Exchange (ETDEWEB)

    Ashley, C.; Zeigler, C. C.; Culp, P. A.

    1982-01-01

    This report contains summaries of releases of radioactivity to onsite seepage basins and to plant effluents for each year since plant startup (1954 through 1980). Releases for the years 1954 through 1959 were reassessed in 1974 and assigned release values for specific long-lived radionuclides. These long-lived radionuclides (half-lives greater than 1 year) are the only radionuclides included for the years 1954 through 1970. Since 1970 all detectable radionuclides have been included. Measured migration o radionuclides from F-, H-, and K-Area seepage basins and desorption of /sup 137/Cs from the Four Mile Creek stream bed are included in Summary B of this report. Summaries of monthly releases for 1979 and 1980 and total SRP releases by radionuclide in three categories: liquid to seepage basins, liquid to streams, and atmospheric are also included. Monthly releases for 1979 are included because the 1979 issue of this report was not published. All 1979 data are included in this report.

  4. Migration of radionuclides through a river system

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    Migration behavior of several atmospherically-derived radionuclides in a river watershed was studied. A main interest was in their relocation from the ground soil of the watershed to a downstream region through a river. Studied radionuclides are: {sup 137}Cs generated by weapon tests in the atmosphere; {sup 210}Pb and {sup 7}Be of naturally occurring radionuclides; {sup 137}Cs, {sup 90}Sr, {sup 239,240}Pu and {sup 241}Am released by the Chernobyl nuclear power plant accident. Dominance of the form in suspended solid in river water (particulate form) was qualified for the radionuclides in the Kuji river watershed. An importance of discharge in flooding was also confirmed. A historical budget analysis for weapon test derived {sup 137}Cs was presented for the Hi-i river watershed and its accompanied lake sediment (Lake Shinji). The work afforded a scheme of a fate of {sup 137}Cs after falling on the ground soil and on the lake surface. Several controlling factors, which can influence on the chemical form of radionuclides discharged to a river, were also investigated in the vicinity of the Chernobyl nuclear power plant. A special attention was paid on the association of the radionuclides with dissolved species in water. Preferential association of Pu and Am isotopes to a large molecular size of dissolved matrices, probably of humic substances, was suggested. (author)

  5. An overview of BORIS: Bioavailability of Radionuclides in Soils

    International Nuclear Information System (INIS)

    Tamponnet, C.; Martin-Garin, A.; Gonze, M.-A.; Parekh, N.; Vallejo, R.; Sauras-Yera, T.; Casadesus, J.; Plassard, C.; Staunton, S.; Norden, M.; Avila, R.; Shaw, G.

    2008-01-01

    The ability to predict the consequences of an accidental release of radionuclides relies mainly on the level of understanding of the mechanisms involved in radionuclide interactions with different components of agricultural and natural ecosystems and their formalisation into predictive models. Numerous studies and databases on contaminated agricultural and natural areas have been obtained, but their use to enhance our prediction ability has been largely limited by their unresolved variability. Such variability seems to stem from incomplete knowledge about radionuclide interactions with the soil matrix, soil moisture, and biological elements in the soil and additional pollutants, which may be found in such soils. In the 5th European Framework Programme entitled Bioavailability of Radionuclides in Soils (BORIS), we investigated the role of the abiotic (soil components and soil structure) and biological elements (organic compounds, plants, mycorrhiza, and microbes) in radionuclide sorption/desorption in soils and radionuclide uptake/release by plants. Because of the importance of their radioisotopes, the bioavailability of three elements, caesium, strontium, and technetium has been followed. The role of one additional non-radioactive pollutant (copper) has been scrutinised in some cases. Role of microorganisms (e.g., K d for caesium and strontium in organic soils is much greater in the presence of microorganisms than in their absence), plant physiology (e.g., changes in plant physiology affect radionuclide uptake by plants), and the presence of mycorrhizal fungi (e.g., interferes with the uptake of radionuclides by plants) have been demonstrated. Knowledge acquired from these experiments has been incorporated into two mechanistic models CHEMFAST and BIORUR, specifically modelling radionuclide sorption/desorption from soil matrices and radionuclide uptake by/release from plants. These mechanistic models have been incorporated into an assessment model to enhance its

  6. An overview of BORIS: Bioavailability of Radionuclides in Soils

    Energy Technology Data Exchange (ETDEWEB)

    Tamponnet, C. [Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, B.P. 1, 13108 Saint-Paul-lez-Durance, Cedex (France)], E-mail: christian.tamponnet@irsn.fr; Martin-Garin, A.; Gonze, M.-A. [Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, B.P. 1, 13108 Saint-Paul-lez-Durance, Cedex (France); Parekh, N. [Center for Ecology and Hydrology, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Vallejo, R.; Sauras-Yera, T.; Casadesus, J. [Department of Plant Biology, University of Barcelona, 08028 Barcelona (Spain); Plassard, C.; Staunton, S. [INRA, UMR Rhizosphere and Symbiosis, Place Viala, 34060 Montpellier (France); Norden, M. [Swedish Radiation Protection Institute, 171 16 Stockholm (Sweden); Avila, R. [Facilia AB, Valsgaerdevaegen 12, 168 53 Bromma, Stockholm (Sweden); Shaw, G. [Division of Agricultural and Environmental Sciences University Park, Nottingham NG7 2RD (United Kingdom)

    2008-05-15

    The ability to predict the consequences of an accidental release of radionuclides relies mainly on the level of understanding of the mechanisms involved in radionuclide interactions with different components of agricultural and natural ecosystems and their formalisation into predictive models. Numerous studies and databases on contaminated agricultural and natural areas have been obtained, but their use to enhance our prediction ability has been largely limited by their unresolved variability. Such variability seems to stem from incomplete knowledge about radionuclide interactions with the soil matrix, soil moisture, and biological elements in the soil and additional pollutants, which may be found in such soils. In the 5th European Framework Programme entitled Bioavailability of Radionuclides in Soils (BORIS), we investigated the role of the abiotic (soil components and soil structure) and biological elements (organic compounds, plants, mycorrhiza, and microbes) in radionuclide sorption/desorption in soils and radionuclide uptake/release by plants. Because of the importance of their radioisotopes, the bioavailability of three elements, caesium, strontium, and technetium has been followed. The role of one additional non-radioactive pollutant (copper) has been scrutinised in some cases. Role of microorganisms (e.g., K{sub d} for caesium and strontium in organic soils is much greater in the presence of microorganisms than in their absence), plant physiology (e.g., changes in plant physiology affect radionuclide uptake by plants), and the presence of mycorrhizal fungi (e.g., interferes with the uptake of radionuclides by plants) have been demonstrated. Knowledge acquired from these experiments has been incorporated into two mechanistic models CHEMFAST and BIORUR, specifically modelling radionuclide sorption/desorption from soil matrices and radionuclide uptake by/release from plants. These mechanistic models have been incorporated into an assessment model to enhance

  7. Cenotic and physiological control of the radionuclides migration into system soil-plant

    International Nuclear Information System (INIS)

    Kravets, A.P.

    1998-01-01

    Some biological - cenotic and physiological - factors which determine the availability of radionuclides for a plant and the general capacity for the accumulation of pollutants were investigated and analysed. Metabolites of soil microorganisms and especially root excretion of higher plants increase the rate of destruction of solid forms of pollution and enhance the leaching of radionuclides from the solid matrix. The following facts were demonstrated in the conditions of contamination heterogeneity of Chernobyl fallout: (i) During the period of vegetation the plants of different species of f. Poacea, 1 .5 to 2.7-fold increase in the chemical mobility and biological availability of radionuclides; (ii) Additional increase in the concentration of soil microorganisms (micromycetes) leads to enhanced contents of the mobile form of the pollutant in soil and increases the level of accumulation of the radionuclides by higher plants; (iii) Increase in the density of sowing (and competition, respectively) of the different species of the plants also leads to an enhanced availability of the radionuclides and 1 .7 to 2.4- fold increase in the level of accumulation of the radionuclides by the plants. Other aspect of formation of the level of plant pollution include the peculiarities of radionuclide absorption and accumulation by the plant biomass. The effects of a high density of sowing, high level of the watering and gamma irradiation on the changes in the level of radionuclide accumulation and, at the same time, the cation exchange capacity (CEC) of the plant biomass were investigated in the laboratory and in a greenhouse experiment. In parallel, increased CEC and radionuclide accumulation by a factor of 1.5 to 2.7 was demonstrated. These facts suggest that the biological factors are a powerful tool of control of the pollutants availability and accumulation and may be take into account under development of the modern agricultural technology for clear products formation

  8. Interaction of radionuclides in severe accident conditions

    International Nuclear Information System (INIS)

    Nagrale, Dhanesh B.; Bera, Subrata; Deo, Anuj Kumar; Paul, U.K.; Prasad, M.; Gaikwad, A.J.

    2015-01-01

    Nuclear power plants are designed with inherent engineering safety systems and associated operational procedures that provide an in-depth defence against accidents. Radionuclides such as Iodine, Cesium, Tellurium, Barium, Strontium, Rubidium, Molybdenum and many others may get released during a severe accident. Among these, Iodine, one of the fission products, behaviour is significant for the analysis of severe accident consequences because iodine is a chemically more active to the potential components released to the environment. During severe accident, Iodine is released and transported in aqueous, organic and inorganic forms. Iodine release from fuel, iodine transport in primary coolant system, containment, and reaction with control rods are some of the important phases in a severe accident scenario. The behaviour of iodine is governed by aerosol physics, depletion mechanisms gravitational settling, diffusiophoresis and thermophoresis. The presence of gaseous organic compounds and oxidizing compounds on iodine, reactions of aerosol iodine with boron and formation of cesium iodide which results in more volatile iodine release in containment play significant roles. Water radiolysis products due to presence of dissolved impurities, chloride ions, organic impurities should be considered while calculating iodine release. Containment filtered venting system (CFVS) consists of venturi scrubber and a scrubber tank which is dosed with NaOH and NaS_2O_3 in water where iodine will react with the chemicals and convert into NaI and Na_2SO_4. This paper elaborates the issues with respect to interaction of radionuclides and its consideration in modeling of severe accident. (author)

  9. Simulation of radionuclide transport in U.S. agriculture

    International Nuclear Information System (INIS)

    Sharp, R.D.; Baes, C.F. III.

    1982-01-01

    Because of the recent concern about the impact of energy technologies on man and related health effects, there has emerged a need for models to calculate or predict the effects of radionuclides on man. A general overview is presented of a model that calculates the ingrowth of radionuclides into man's food chain. The FORTRAN IV computer program TERRA, Transport of Environmentally Released Radionuclides in Agriculture, simulates the build-up of radionuclides in soil, four plant food compartments, in meat and milk from beef, and in the livestock food compartments that cause radionuclide build-up in milk and meat from beef. A large data set of spatially oriented parameters has been developed in conjunction with TERRA. This direct-access data set is called SITE, Specific Information on the Terrestrial Environment, and contains 35 parameters for each of 3525 half-degree longitude-latitude cells which define the lower 48 states. TERRA and SITE are used together as a package for determining radionuclide concentrations in man's food anywhere within the conterminous 48 states due to atmospheric releases

  10. Radionuclide trap

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1978-01-01

    The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition

  11. Drift-Scale Radionuclide Transport

    International Nuclear Information System (INIS)

    Houseworth, J.

    2004-01-01

    drift. The reason for introducing the fracture-matrix partitioning model is to broaden the conceptual model for flow beneath waste emplacement drifts in a way that does not rely on the specific flow behavior predicted by a dual continuum model and to ensure that radionuclide transport is not underestimated. The fracture-matrix partitioning model provides an alternative method of computing the partitioning of radionuclide releases from drifts without seepage into rock fractures and rock matrix. Drifts without seepage are much more likely to have a significant fraction of radionuclide releases into the rock matrix, and therefore warrant additional attention in terms of the partitioning model used for TSPA

  12. Diffusion of radionuclide chains through an adsorbing medium

    International Nuclear Information System (INIS)

    Burkholder, H.C.; DeFigh-Price, C.

    1977-01-01

    The diffusion of radionuclide chains from an underground nuclear waste disposal site through the surrounding geologic medium to the surface is investigated for impulse and band releases. Numerical calculation of the analytical solutions shows that differences in adsorption characteristics among chain members and radioactive decay during transit reduce radionuclide discharges to the biosphere. Results suggest that molecular diffusion is unlikely to be an important transfer mechanism from geologic isolation, and that disposal of radionuclides in deep geologic formations and in the seabed under conditions of very low or nonexistent water flow is likely to be very effective in preventing radioactivity releases to the biosphere

  13. Use of depleted uranium silicate glass to minimize release of radionuclides from spent nuclear fuel waste packages

    International Nuclear Information System (INIS)

    Forsberg, C.W.

    1996-01-01

    A Depleted Uranium Silicate Container Backfill System (DUSCOBS) is proposed that would use small, isotopically-depleted uranium silicate glass beads as a backfill material inside repository waste packages containing spent nuclear fuel (SNF). The uranium silicate glass beads would fill the void space inside the package including the coolant channels inside SNF assemblies. Based on preliminary analysis, the following benefits have been identified. DUSCOBS improves repository waste package performance by three mechanisms. First, it reduces the radionuclide releases from SNF when water enters the waste package by creating a local uranium silicate saturated groundwater environment that suppresses (a) the dissolution and/or transformation of uranium dioxide fuel pellets and, hence, (b) the release of radionuclides incorporated into the SNF pellets. Second, the potential for long-term nuclear criticality is reduced by isotopic exchange of enriched uranium in SNF with the depleted uranium (DU) in the glass. Third, the backfill reduces radiation interactions between SNF and the local environment (package and local geology) and thus reduces generation of hydrogen, acids, and other chemicals that degrade the waste package system. Finally, DUSCOBS provides a potential method to dispose of significant quantities of excess DU from uranium enrichment plants at potential economic savings. DUSCOBS is a new concept. Consequently, the concept has not been optimized or demonstrated in laboratory experiments

  14. Sources and distribution of anthropogenic radionuclides in different marine environments

    International Nuclear Information System (INIS)

    Holm, E.

    1997-01-01

    The knowledge of the distribution in time and space radiologically important radionuclides from different sources in different marine environments is important for assessment of dose commitment following controlled or accidental releases and for detecting eventual new sources. Present sources from nuclear explosion tests, releases from nuclear facilities and the Chernobyl accident provide a tool for such studies. The different sources can be distinguished by different isotopic and radionuclide composition. Results show that radiocaesium behaves rather conservatively in the south and north Atlantic while plutonium has a residence time of about 8 years. On the other hand enhanced concentrations of plutonium in surface waters in arctic regions where vertical mixing is small and iceformation plays an important role. Significantly increased concentrations of plutonium are also found below the oxic layer in anoxic basins due to geochemical concentration. (author)

  15. The variability of the potential radiation exposure to man arising from radionuclides released to the ground water

    International Nuclear Information System (INIS)

    Proehl, G.; Mueller, H.

    1994-12-01

    The variability of the potential radiation exposure of the population is estimated if radionuclides (Np-237, Tc-99, I-129, Cs-135, Ra-226, U-238) are released to the ground water which is used by man as drinking water for humans and animals, for irrigation of food and feed crops, and for the production of fish in freshwater bodies. Annual effective dose equivalents are calculated assuming a normalized activity concentration in the water of 1 Bq/l for each radionuclide considered. An important aim is the estimation of the uncertainty of the exposure due to the uncertainty and the variability of the input parameters. The estimated frequency distributions of the input parameters were used as a model input and processed with Latin Hypercube Sampling and a Monte-Carlo technique. This estimation is based on an exposure scenario which reflects the present conditions. The critical group for the exposure due to the use of contaminated ground water are for most radionuclides the children of 1 year, although the activity intake of children is much lower than for adults. However the ingestion dose factors for infants are higher; in many cases the differences are higher than a factor of 5. (orig./HP)

  16. Dose rates as a function of time due to postulated radionuclide releases from the U.S. Yucca Mountain high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Moeller, Dade W.; Sun, Lin-Shen C.; Cherry, Robert

    2008-01-01

    The Yucca Mountain repository, which is located in a remote area in the State of Nevada, is being constructed for the long-term care and disposal of spent nuclear fuel and vitrified high-level radioactive waste. In accordance with U.S. law, the U.S. Environmental Protection Agency (USEPA) promulgated Standards that limit the dose rates to members of the public due to the consumption of ground water, alone, and the consumption of ground water plus agricultural products irrigated with the contaminated ground water, and other exposures, such as those from external sources and the inhalation of airborne radioactive materials. As part of this exercise, the USEPA identified eight specific radionuclides to which their Standards are to apply. These are: 14 C, 99 Tc, 129 I, 226 Ra, 228 Ra, 237 Np, 239 Pu, and 241 Am. For purposes of the associated dose rate estimates, a range of conservative assumptions have been applied, all of which are designed to assure that the estimated dose rates are well above what might be expected under 'real-world' conditions. As a first step, it was assumed that: (1) at 10 4 year after repository closure, a fractional release of 10 -5 of the entire repository radionuclide inventory occurred; (2) the only prior reduction in the inventory was that due to radioactive decay; and (3) the sole path of exposure to neighboring population groups was through the consumption of 2 L d -1 of contaminated ground water. The accompanying analyses revealed that, of the eight radionuclides, only 226 Ra, 237 Np, and 239 Pu, will represent a significant source of dose at that time. To provide perspective and insights, the next step was to estimate the committed effective dose rates for all eight radionuclides based on an assumed fractional release each year of 10 -5 of the inventory from the time of repository closure up through the 10 6 year. For purposes of providing perspective, it was assumed that each dose rate estimate was independent, that is, no releases

  17. Fire fighting in a radionuclide laboratory

    International Nuclear Information System (INIS)

    Wenzel, H.

    1991-01-01

    A fire-brigade was called to a laboratory which held a handling licence for the radionuclides C-14, T, P-32, Se-75, Mo-99, and S-35. The fire-brigade was unaware of a release of radionuclides. Therefore they used respiratory equipment, and all persons present were subsequently examined for contamination. (DG) [de

  18. Forecast of radionuclides release from actual waste form geometries

    International Nuclear Information System (INIS)

    Suarez, A.A.; Rzyski, B.M.; Sato, I.M.

    1989-01-01

    The complete understanding of the leaching mechanism of radionuclides from solid comentitious waste forms is still far from being reached. Much effort has been devoted, however, to identifying and explaining the main components which contribute to the dispersal of radionuclides out of the waste form to the environment. This is of prime importance when short term results are extrapolated into the future. The diffusion coefficient evaluation, based on experimental leaching data obtained from samples produced from the same batch was performed using the exact diffusion formulation applied to real geometric sample shape. This paper discusses the evaluation

  19. Advice concerning radionuclide release of nuclear power plants and public health

    International Nuclear Information System (INIS)

    1984-01-01

    Amongst the severe accidents with nuclear power plants, a number of scenario's is theoretically possible. These scenario's lead to more or less serious consequences for the environment. Characteristics for the category of accidents was the early breakdown of the containment of the reactor. In recent years more and more doubt has risen with regard to the most serious scenario KE. In the Netherlands the Committee for Reactor Safety (CRV) has reported on this subject (annex 1). According to the CRV the release of a number of important radionuclides, in the case of scenario KE, will be very much less than was supposed in the past. Also, the nuclides will be released much later than was supposed before. A committee of the Dutch Health Council, starting from the CRV-report, has made calculations on the radiological consequences of the KE-scenario, corrected in accordance with these new developments (KEH). As could be expected, this category KEH proves to be considerably less dangerous than was supposed before. Irradiation of the surrounding population with a lethal dose would not occur anymore. The number of somatic and genetic effects would be very small. The conclusions drawn from these calculations are given. These results are compared with calculated consequences of an accident of the KM-category. The CRV has defined a maximised accident from this category (KMM). The report includes the report of the Dutch Commission on Reactor Safety (CR-82-71) as an appendix. (Auth.)

  20. 1{sup st} annual workshop proceedings of the collaborative project ''Fast/instant release of safety relevant radionuclides from spent nuclear fuel'' (7{sup th} EC FP CP FIRST-Nuclides)

    Energy Technology Data Exchange (ETDEWEB)

    Kienzler, Bernhard; Metz, Volker; Duro, Lara; Valls, Alba (eds.)

    2013-07-01

    place at the rim of the fuel pellets. The physico-chemical properties of the fuel are further complicated by additions of gadolinium oxide and/or chromium oxide, which is used for criticality control or to adjust the UO{sub 2} grain sizes for minimizing fission gas release (FGR). Moreover, the fission products of uranium cause expansion in the UO{sub 2} crystal structure leading to disturbances of the fuel matrix. The chemical stability of the fission products oxides in the UO{sub 2} matrix, can be classified into different groups: (i) the rare earth elements and Y, Zr, Ba and Sr, whose oxides form either solid solutions with UO{sub 2} or single phase precipitates; (ii) Mo, Cs and Rb, which are either oxidized or not, depending on the O/U ratio; and (iii) elements like Ru, with unstable oxides which form metallic precipitates within the UO{sub 2}. The CP is organized in six workpackages (WP): WP1, ''Samples and tools'' deals with the selection, characterization and preparation of the materials to be studied and the set-up of experimental and organisational tools. In this sense, one of the essential requirements of the project is that typical and sufficiently well characterized spent nuclear fuel is being used for the experiments and modelling studies. WP2 covers the ''Gas release and rim and grain boundary diffusion experiments'' and WP3 addresses ''Dissolution based release studies''. This includes determining the chemical form of released radionuclides, fission gases, {sup 135}Cs, {sup 129}I, {sup 14}C, {sup 79}Se, {sup 99}Tc and {sup 126}Sn. WP4 ''Modelling'' deals with modelling of release/retention processes of fission products in the spent fuel structure. Special attention is attributed to fission product migration along the grain boundaries, the effects of fractures in the pellets and of holes/fractures in the cladding. The modelling work within FIRST-Nuclides will help to clarify

  1. Behaviour and fate radionuclides in soils. Mathematical modelling and experimental investigations

    International Nuclear Information System (INIS)

    Rovdan, E.N.

    2003-01-01

    The uncontrolled release of radionuclides as result of Chernobyl accident has led to contamination of 23% of territory of Republic of Belarus. Soil has high capacity to adsorb radionuclides and their intensive sorption provides the creation of a long-lived radionuclide source in a terrestrial environment. In the management of the contaminated areas and application of a countermeasure strategy it is extremely important to know the environmental mechanisms governing the behaviour of radionuclides in soils. Basic attention in the work is paid to the study of 137 Cs and 90 Sr because they are the main radionuclides from the view point of radioactive danger in polluted areas. The main features and processes that control radionuclide behaviour in soil have been analysed. On the basis of natural researches, lab test and mathematical modelling the impact of physical-chemical factors and the soil component composition changes upon the radionuclides migration and sorption in natural dispersed systems (peat, sand, bentonite, kaolin, sapropel) has been investigated. The investigations done allowed to substantiate the mathematical models of the radionuclides migration in the regions of positive and negative temperatures, to develop methods of experimental identification of main transfer characteristics and to compile a data base for these models. (orig.)

  2. Analytical evaluation of the radionuclide concentration through the aquifer for the Abadia de Goias Repository

    International Nuclear Information System (INIS)

    Alves, Antonio Sergio de Martin

    1999-01-01

    In this paper the radionuclide concentration though the aquifer has been determined by an analytical process considering that the radionuclide migration is influenced by two kinds of radionuclides releases from the repository during an overflow. In the first release it is assumed that when the radionuclides reach the aquifer there is no contamination in it and the release rate is a constant. For this case it is utilized the model of Reference. For the subsequent releases there will be a contamination in the aquifer provenient from the former releases; it is considered that the subsequent releases are a function of the time which, for the Abadia de Goias Repository, was determined in the Reference. The Laplace transform Method has been utilized to solve the Radionuclide Migration Transport Equation in the aquifer region for the subsequent releases and the resulting function is expressed in terms of exponential and complementary error functions. The improvement in the calculation model, presented in this paper, can be used in the safety analysis of repositories, contributing thus in the nuclear waste management field and particularly, being connecting also to the environmental protection concern. (author)

  3. Radionuclide concentrations in white sturgeon from the Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, D.D.; Price, K.R.; Poston, T.M.

    1992-09-01

    Although radioactive releases from the US Department of Energy`s Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River.

  4. Radionuclide concentrations in white sturgeon from the Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, D.D.; Price, K.R.; Poston, T.M.

    1992-09-01

    Although radioactive releases from the US Department of Energy's Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River.

  5. Radionuclide concentrations in white sturgeon from the Columbia River

    International Nuclear Information System (INIS)

    Dauble, D.D.; Price, K.R.; Poston, T.M.

    1992-09-01

    Although radioactive releases from the US Department of Energy's Hanford Site have been monitored in the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed interest in estimating human exposure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon (Acipenser transmontanus) were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species in the Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of industrial radionuclides in white sturgeon and to collect additional data on current body burdens in the Columbia River

  6. Critical Radionuclide and Pathway Analysis for the Savannah River Site, 2016 Update

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, Tim [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hartman, Larry [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-08

    During the operational history of Savannah River Site, many different radionuclides have been released from site facilities. However, as shown in this analysis, only a relatively small number of the released radionuclides have been significant contributors to doses to the offsite public. This report is an update to the 2011 analysis, Critical Radionuclide and Pathway Analysis for the Savannah River Site. SRS-based Performance Assessments for E-Area, Saltstone, F-Tank Farm, H-Tank Farm, and a Comprehensive SRS Composite Analysis have been completed. The critical radionuclides and pathways identified in those extensive reports are also detailed and included in this analysis.

  7. Modelling the transport of radionuclides released in the Ilha Grande bay (Brazil) after a Large Break Loca ion the primary system of a PWR

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Andre Silva de; Simoes Filho, Francisco Fernando Lamego; Soares, Abner Duarte; Lapa, Celso Marcelo Franklin, E-mail: flamego@ien.gov.b, E-mail: asoares@cnen.gov.b, E-mail: lapa@ien.gov.b [Instituto de Engenharia Nuclear (LIMA/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    It was postulated, in the cooling system of the core, a LOCA, where 431 m{sup 3} of soda almost instantaneously was lost. This inventory contained 1.87x10{sup 10} Bq/m{sup 3} of tritium, 2.22x10{sup 7} Bq/m{sup 3} of cobalt,3.48x10{sup 8} Bq/m{sup 3} of cesium and 3.44x10{sup 10} Bq/m{sup 3} of iodine and was released in liquid form near the Itaorna cove, Angra dos Reis - RJ. Applying the model in the proposed scenario (Angra 1 and 2 in operation and Angra 3 progressively reducing the capture and discharge after the accident), the simulated dilution of the specific activity of radionuclide spots, reached values much lower than report levels for seawater (1,1x10{sup 6} Bq/m{sup 3}, 1,11x10{sup 4} Bq/m{sup 3} and 1,85x10{sup 3} Bq/m{sup 3}) after 22 hours, respectively for {sup 3}H, {sup 60}Co, {sup 131}I and {sup 137}Cs. From the standpoint of public exposure to radionuclide dispersion, the results of activity concentration obtained by the model suggest that the observed radiological impact is negligible. Based on these findings, we conclude that there would be no radiological impact related to a further release of controlled effluent discharges into Itaorna cove. (author)

  8. The RADionuclide Transport, Removal, and Dose (RADTRAD) code

    International Nuclear Information System (INIS)

    Miller, L.A.; Chanin, D.I.; Lee, J.

    1993-01-01

    The RADionuclide Transport, Removal, And Dose (RADTRAD) code is designed for US Nuclear Regulatory Commission (USNRC) use to calculate the radiological consequences to the offsite population and to control room operators following a design-basis accident at Light Water Reactor (LWR) power plants. This code utilizes updated reactor accident source terms published in draft NUREG-1465, ''Accident Source Terms for Light-Water Nuclear Power Plants.'' The code will track the transport of radionuclides as they are released from the reactor pressure vessel, travel through the primary containment and other buildings, and are released to the environment. As the radioactive material is transported through the primary containment and other buildings, credit for several removal mechanisms may be taken including sprays, suppression pools, overlying pools, filters, and natural deposition. Simple models are available for these different removal mechanisms that use, as input, information about the conditions in the plant and predict either a removal coefficient (λ) or decontamination factor. The user may elect to use these models or input a single value for a removal coefficient or decontamination factor

  9. Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem.

    Science.gov (United States)

    Smith, G M; Smith, K L; Kowe, R; Pérez-Sánchez, D; Thorne, M; Thiry, Y; Read, D; Molinero, J

    2014-05-01

    Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, www.bioprota.org. Copyright © 2013 Elsevier Ltd. All

  10. Radioanalytical procedures used to study the release of radionuclides from spent nuclear fuel and the diffusion into bentonite clay

    International Nuclear Information System (INIS)

    Ramebaeck, H.; Albinsson, Yngve; Skaalberg, M.; Eklund, U.B.

    1999-12-01

    This report presents radio-analytical procedures for the assay of 90 Sr, 99 Tc, 237 Np, 239 Pu, 241 Am and 244 Cm. These analytical procedures were used in a project studying the release and diffusion of radionuclides from spent nuclear fuel into bentonite clay. The main task was to use methods giving a high specificity in the detection combined with a low detection limit. A high specificity will eliminate errors caused by interferences, yielding errors in the analysis. A low detection limit was necessary since the release was often very low. Solvent extraction was used in order to remove interferences. The detection methods, radiometric or mass spectrometric, were chosen to give the lowest detection limit

  11. Behaviour of radionuclides in meadows including countermeasures application

    International Nuclear Information System (INIS)

    Prister, B.S.; Ivanov, Yu.A.; Perepelyatnikov, G.P.; Il'yn, M.I.; Belli, M.; Sanzharova, N.I.; Fesenko, S.V.; Alexakhin, R.M.; Bunzl, K.; Petriaev, E.P.; Sokolik, G.A.

    1996-01-01

    Main regularities of the behaviour of ChNPP release radionuclides in components of meadow ecosystems are considered. Developed mathematical model of radionuclide migration in components of meadow ecosystems is discussed. Radioecological classification of meadow ecosystems is proposed. Effectiveness of countermeasures application in meadow ecosystems is estimated

  12. Radionuclides in sediments and seawater at Rongelap Atoll

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V.E.; Robison, W.L.; Eagle, R.J.; Brunk, J.L.

    1998-03-01

    The present concentrations and distributions of long-lived, man-made radionuclides in Rongelap Atoll lagoon surface sediments, based on samples collected and analyzed in this report. The radionuclides were associated with debris generated with the 1954 Bravo thermonuclear test at Bikini Atoll. Presently, only {sup 90}Sr and the transuranic radionuclides are found associated with the surface sediments in any quantity. Other radionuclides, including {sup 60}Co and {sup 137} Cs, are virtually absent and have either decayed or migrated from the deposits to the overlying seawater. Present inventories of {sup 241}Am and {sup 249+240}Pu in the surface layer at Rongelap are estimated to be 3% of the respective inventories in surface sediments from Bikini Atoll. There is a continuous slow release of the transuranics from the sediments back to the water column. The inventories will only slowly change with time unless the chemical-physical processes that now regulate this release to the water column are changed or altered.

  13. Evaluation of radionuclide releases from underground waste repositories using the method of status vectors

    International Nuclear Information System (INIS)

    Zappe, D.

    1983-01-01

    For safety analyses of underground repositories for radioactive wastes various possible release scenarios have to be defind and anticipated consequences to be calculated and compared. Normally only the main exposure pathways (i.e. the critical pathways) of the radionuclides disposed of in the repository are calculated using deterministic methods and varying the parameters. It is proposed to evaluate all the individual pathways including those differing considerably from the critical pathway by forming weighted averages of their consequences. This offers the possibility of including, without any restriction, in the evaluation of the repository the various possible events and processes that influence the function of barriers for the retention of radionuclides. Various states (scenarios) of a repository in a salt formation, which might occur in the course of time have been used as an example. The consequences related to these states and the probabilities of their occurrence or the scenario weights form the components of 'status vectors'. For low- and intermediate-level wastes the overall consequences obtained from these calculations are negligibly small, for high-level wastes they are about 3 x 10 - 5 Sv a - 1 /GW a. These values are reached if at least a part of the barriers is effective. Variations of the weighting factors for the states and their influence on the overall consequences are given. (author)

  14. Interaction between water, sediments and radionuclides

    International Nuclear Information System (INIS)

    Snodgrass, W.J.; McKee, P.; Garnett, J.; Stieff, L.

    1988-08-01

    A model-based measurements program was carried out to evaluate the primary mechanisms controlling transport of uranium 238 and thorium 232 decay chain radionuclides in Quirke Lake, a water body draining much of the uranium mining and milling district near Elliot Lake, Ontario. This program included studies of radionuclide accumulation in sediments, particle settling and lake mass-balance studies. Also, sediment studies were undertaken to evaluate chemical fractionation, mineralogical associations, and sediment-water adsorption and release. A limnocorral experiment was conducted in an isolated portion of a lake to measure radium 226 removal from the water column and diffusion from the sediments back to the water. Modelling studies were made to assess the data. Substantial agreement was obtained using the model originally developed for the AECB between model predictions and observations for Quirke Lake and for the limnocorrals. Further work is required to complete the studies undertaken in this project to assess the significance of the efflux of radionuclides from the sediments. These studies include a laboratory program to measure kinetics of adsorption, sediment-water modelling studies of the results and a field measurement program to develop a mass-balance analysis for thorium. (numerous refs)

  15. ACCI38 XL 2: a useful tool for dose assessment in case of accidental atmospheric releases of radionuclides

    International Nuclear Information System (INIS)

    Thomassin, A.; Merle-Szeremeta, A.

    2002-01-01

    In the scope of its assignments in the field of nuclear risks, the French Institute for Radiation protection and Nuclear Safety (IRSN) develops tools to assess the impact of nuclear facilities on their environment and surrounding populations. The code ACCI38 XL 2 is a tool dedicated to the assessment of integrated concentrations in the environment and of dosimetric consequences on man, in case of accidental atmospheric releases of radionuclides (up to 170 radionuclides). This code is widely used by IRSN for studies on accidents, mainly for the analysis of regulatory documents from nuclear operators. The aim of this communication is to present the main features of the model used in the code ACCI38 XL 2, and to give details about the code. After a general presentation of the model, a detailed description of atmospheric dispersion, transfer in the environment and radiological impact is given. Then, some information on parameters and limitations of the model and the code are presented

  16. Seminar on Comparative assessment of the environmental impact of radionuclides released during three major nuclear accidents: Kyshtym, Windscale, Chernobyl. Vol. 1

    International Nuclear Information System (INIS)

    1991-01-01

    These proceedings of seminar on comparative assessment of the environmental impact of radionuclides released during three major nuclear accidents (Kyshtym, Windscale, Chernobyl) are divided into 5 parts bearing on: part 1: accident source terms; part 2: atmospheric dispersion, resuspension, chemical and physical forms of contamination; part 3: environmental contamination and transfer; part 4: radiological implications for man and his environment; part 5: countermeasures

  17. Assessment of an accidental fuel radionuclide release data from the damaged Chernobyl NPP unit 4

    International Nuclear Information System (INIS)

    Mikhajlov, O.V.; Doroshenko, A.O.

    2015-01-01

    A procedure and results of assessment of fuel temperature dynamics during the formation of lava-like fuel containing materials (LFCM) in room 305/2 are presented. The assessment of the overheated fuel temperature carried out using mathematical type codes CORSOR's type from the known radionuclide release data in the period from 26.04 to 11.05.86. It is shown that the main LFCM's accumulations could be formed at a moderate value of temperatures than previously estimated. The obtained data were used to verify the ''blast furnace'' version of LFCM formation and formation of FCM with high uranium concentration and temperature of the core fragment's charge

  18. Migration of radionuclides in fissured rock

    International Nuclear Information System (INIS)

    Neretnieks, I.

    1982-01-01

    Some computed results of radionuclide migration in fissured rock are presented. The computations are based on a model which describes flow as occurring in a multitude of independent fissures (stratified flow). This gives rise to strong dispersion of channeling. The radionuclide migration in the individual fissures is modelled by the advection equation on a parallel walled channel with porous walls. The nuclides may diffuse into the pores and sorb reversibly on the pore surfaces. The effluent rates of 23 important nuclides are presented as functions of distance and time for various of important parameters such as rock permeability, diffusion coefficients, release rates, time of first release, fissure spacing and fissure width distribution. (Author)

  19. Environmentally important radionuclides in non-proliferative fuel cycles

    International Nuclear Information System (INIS)

    Kaye, S.V.; Till, J.E.

    1978-01-01

    Increased emphasis in energy research is being given to the development of nonproliferative nuclear fuel cycles and to the assessment of potential release of radionuclides to the environment from these new cycles. Four radionuclides, 14 C, 3 H, 99 Tc, and 232 U, due to lack of adequate knowledge or anticipated increased production in nonproliferative fuel cycles, may require renewed consideration. Our projections indicate that releases of 14 C by the global nuclear industry could exceed the natural production rate of 3.8 x 10 4 Ci/y by the year 2000 and could eventually stabilize at 2.3 times that rate. Tritium may become increasingly important, because recent data from fast reactors (of the nonproliferative type) have confirmed production rates up to 13 times greater than previous estimates. Present radwaste systems do not remove tritium. Recent experiments on the uptake of 99 Tc reveal that soil-to-plant concentration factors for technetium appear to be two to three orders of magnitude greater than the value of 0.25 which has been adopted routinely in radiological assessments. Research is needed to determine reliable 99 Tc soil-to-plant concentration factors because this radionuclide could be released at reprocessing and enrichment facilities. New calculations for certain reactors indicate that 232 U may be formed in concentrations up to 4000 ppm. If accurate, such data will require careful analysis of possible releases of 232 U because of external and food chain exposures. The environmental health aspects of these four radionuclides are discussed, as well as the potential for their release to the environment from nonproliferative fuel cycles. (author)

  20. Inclusion of radionuclides absorption by sediments in the RIVLAK program

    International Nuclear Information System (INIS)

    Rodrigues Junior, O.; Moreira, J.M.L.

    1992-01-01

    The RIVLAK code solves the one-dimensional transport equation for radionuclide concentrations within a water body for routine and accidental releases of liquid effluents. The principal phenomena considered in the RIVLAK code are advection by the water body flow, longitudinal and transversal diffusion, and radioactive decay. This work incorporates the interaction between radionuclides and suspended or bed sediments to the RIVLAK code. An approximate equation for the radionuclide concentration in an effective sediment is included in the code with explicit terms for adsorption and desorption from the water to the effective sediment. The modified RIVLAK code is utilized for estimating the radionuclide concentration from release experiments in the Clinch river. The original code overestimates the Cs concentration downstream by approximately two orders of magnitude. The modified version predicts the Cs concentration with few percents, and underestimates its longitudinal dispersion by about 35%. The special care needed with parameters such as the radionuclide diffusion coefficient in the water, and the adsorption and desorption coefficients are discussed. (author)

  1. Releases of radioactivity at the Savannah River Plant, 1954--1975

    International Nuclear Information System (INIS)

    Ashley, C.; Zeigler, C.C.

    1976-07-01

    This report contains summaries of releases of radioactivity to the environs from the Savannah River Plant for each year since plant startup (1954-1975). It also contains monthly summaries of 1975 releases from major emission sources (Separations and Reactor Areas). Releases for the years 1954 through 1959 are reassessed and assigned release values for long-lived specific radionuclides. These long-lived radionuclides (half lives greater than one year) are the only radionuclides included for the years 1954 through 1970. Beginning in 1971 all detectable radionuclides are included. The tabulated data, now compiled by computer, will be updated annually. All measured migration of radioactivity from the F- and H-Area seepage basin systems to Four Mile Creek, and from the K-Area containment basin to Pen Branch is listed in the release summaries and will be updated annually

  2. Quality control of radionuclide calibrators used in nuclear medicine services in the Brazilian northeast region

    International Nuclear Information System (INIS)

    Fragoso, Maria C.F.; Albuquerque, Antonio M.S.; Oliveira, Mercia L.; Lima, Ricardo A.; Lima, Fabiana F.

    2011-01-01

    The radionuclide calibrators are essential instruments in nuclear medicine services in order to activity determination of radiopharmaceuticals which will be administered to the patients. Inappropriate performance of these equipment could provide underestimation or overestimation of the activity, compromising the success of diagnosis or therapeutic procedures. To ensure the satisfactory performance of the radionuclide calibrators, quality control tests are recommended by national and international guides. The aim of this work was evaluate the establishment of the quality control program in the radionuclide calibrators at medicine nuclear services in the Brazilian northeast region, highlighting the tests and their frequencies. (author)

  3. Radionuclide distributions and sorption behavior in the Susquehanna--Chesapeake Bay System

    International Nuclear Information System (INIS)

    Olsen, C.R.; Larsen, I.L.; Lowry, P.D.; McLean, R.I.; Domotor, S.L.

    1989-01-01

    Radionuclides released into the Susquehanna--Chesapeake System from the Three Mile Island, Peach Bottom, and Calvert Cliffs nuclear power plants are partitioned among dissolved, particulate, and biological phases and may thus exist in a number of physical and chemical forms. In this project, we have measured the dissolved and particulate distributions of fallout 137 Cs; reactor-released 137 Cs, 134 Cs, 65 Zn, 60 Co, and 58 Co; and naturally occurring 7 Be and 210 Pb in the lower Susquehanna River and Upper Chesapeake Bay. In addition, we chemically leached suspended particles and bottom sediments in the laboratory to determine radionuclide partitioning among different particulate-sorbing phases to complement the site-specific field data. This information has been used to document the important geochemical processes that affect the transport, sorption, distribution, and fate of reactor-released radionuclides (and by analogy, other trace contaminants) in this river-estuarine system. Knowledge of the mechanisms, kinetic factors, and processes that affect radionuclide distributions is crucial for predicting their biological availability, toxicity, chemical behavior, physical transport, and accumulation in aquatic systems. The results from this project provide the information necessary for developing accurate radionuclide-transport and biological-uptake models. 76 refs., 12 figs

  4. Technogenic radionuclides of Chernobyl NPP accidental release and their physical and chemical forms

    Directory of Open Access Journals (Sweden)

    A. I. Lypska

    2015-10-01

    Full Text Available Distribution of radionuclides in the vertical soil profile on the nearest Chernobyl NPP zone of alienation was investigated. It is showed experimentally that the main activity of radionuclides is concentrated in the topsoil (10 сm. Coefficients of accumulation of 137Cs and 90Sr radionuclides by plants are estimated. The physico-chemical forms of radionuclides in soil and plants were defined using the method of sequential chemical extraction. It was established that the main contents of 137Cs and 90Sr in soils are represented in non-exchange and fixed forms, in plants - mainly in exchange-adsorption and organic forms.

  5. Tracing Fukushima Radionuclides in the Northern Hemisphere -An Overview

    Science.gov (United States)

    Thakur, Punam; Ballard, Sally; Nelson, Roger

    2013-04-01

    A massive 9.0 earthquake and ensuing tsunami struck the northern coast of the Honshu-island, Japan on March 11, 2011 and severely damaged the electric system of the Fukushima- Daiichi Nuclear Power Plant (NPP). The structural damage to the plant disabled the reactor's cooling systems. Subsequent fires, a hydrogen explosion and possible partial core meltdowns released radioactive fission products into the atmosphere. The atmospheric release from the crippled Fukushima NPP started on March 12, 2011 with a maximum release phase from March 14 to 17. The radioactivity released was dominated by volatile fission products including isotopes of the noble gases xenon (Xe-133) and krypton (Kr-85); iodine (I-131,I-132); cesium (Cs-134,Cs-136,Cs-137); and tellurium (Te-132). The non-volatile radionuclides such as isotopes of strontium and plutonium are believed to have remained largely inside the reactor, although there is evidence of plutonium release into the environment. Global air monitoring across the northern hemisphere was increased following the first reports of atmospheric releases. According to the source term, declared by the Nuclear and Industrial Safety Agency (NISA) of Japan), approximately 160 PBq (1 PBq (Peta Becquerel = 10^15 Bq)) of I-131 and 15 PBq of Cs-137 (or 770 PBq "iodine-131 equivalent"), were released into the atmosphere. The 770 PBq figure is about 15% of the Chernobyl release of 5200 PBq of "iodine-131 equivalent". For the assessment of contamination after the accident and to track the transport time of the contaminated air mass released from the Fukushima NPP across the globe, several model calculations were performed by various research groups. All model calculations suggested long-range transport of radionuclides from the damaged Fukushima NPP towards the North American Continent to Europe and to Central Asia. As a result, an elevated level of Fukushima radionuclides were detected in air, rain, milk, and vegetation samples across the northern

  6. Controlled-release tablet formulation of isoniazid.

    Science.gov (United States)

    Jain, N K; Kulkarni, K; Talwar, N

    1992-04-01

    Guar (GG) and Karaya gums (KG) alone and in combination with hydroxy-propylmethylcellulose (HPMC) were evaluated as release retarding materials to formulate a controlled-release tablet dosage form of isoniazid (1). In vitro release of 1 from tablets followed non-Fickian release profile with rapid initial release. Urinary excretion studies in normal subjects showed steady-state levels of 1 for 13 h. In vitro and in vivo data correlated (r = 0.9794). The studies suggested the potentiality of GG and KG as release retarding materials in formulating controlled-release tablet dosage forms of 1.

  7. Remediation of radionuclide pollutants through biosorption - an overview

    Energy Technology Data Exchange (ETDEWEB)

    Das, Nilanjana [Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore (India)

    2012-01-15

    The development of nuclear science and technology has led to the increase of nuclear wastes containing radionuclides to be released and disposed in the environment. Pollution caused by radionuclides is a serious problem throughout the world. To solve the problem, substantial research efforts have been directed worldwide to adopt sustainable technologies for the treatment of radionuclide containing wastes. Biosorption represents a technological innovation as well as a cost effective excellent remediation technology for cleaning up radionuclides from aqueous environment. A variety of biomaterials viz. algae, fungi, bacteria, plant biomass, etc. have been reported for radionuclide remediation with encouraging results. This paper reviews the achievements and current status of radionuclide remediation through biosorption which will provide insights into this research frontier. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Application of innovative policies for controlling radionuclide releases: The open-quotes open-market trading ruleclose quotes

    International Nuclear Information System (INIS)

    Moeller, D.W.

    1997-01-01

    In the past, most efforts for reducing airborne radio nuclide releases and controlling radioactive wastes have been directed to the development of new and improved technologies. Little attention has been paid to the possible application to these problems of new, innovative policies. Yet, experience in other fields shows that such applications could be beneficial. A prime example is the open-quotes open-market trading rule,close quotes now being widely used in the U.S. for the control of a range of environmental problems. Through this rule, nuclear facility operators would be permitted to control airborne emissions in a more cost-effective manner, and those responsible for decommissioning and decontaminating nuclear facilities no longer in operation could do so at far lower costs while generating significantly smaller volumes of radioactive wastes. Application of such a policy would also significantly reduce the demands on existing, and the need for research to develop new, improved, control technologies. 16 refs

  9. Operation and maintenance manuals for VEGA apparatus on radionuclide release from irradiated fuel

    International Nuclear Information System (INIS)

    Hayashida, Retsu; Hidaka, Akihide; Nakamura, Takehiko; Kudo, Tamotsu; Ohtomo, Takashi; Uetsuka, Hiroshi

    2001-03-01

    An experimental program, Verification Experiments of radionuclides Gas/Aerosol release (VEGA), was initiated at JAERI from September 1999 to improve source term predictabilities for hypothetical severe accidents. In the experiment, a short fuel segment taken from LWR fuels irradiated in Japanese power reactors is inductively heated to high temperatures (∼3273K) in a hot cell under high pressure conditions up to 1.0MPa. Particularly, a focus will be placed on the release and transport behaviors of low-volatile fission products (FP), actinides and short-life FP which have not been well investigated in previous studies. This experimental apparatus was completed in February 1999 and three experiments were performed by the end of 2000. Most of these experiments were successfully conducted, but some problems were also found. Especially, in the first VEGA-1 test with the purpose of shakedown and reference data acquisition, there were problems such as flow blockage at the outlet of furnace due to structure melting, malfunction of heaters and so on. Therefore, the design for these defective parts was changed for future experiments. Moreover, the apparatus is not so big but the entire processes are very complicated. Accordingly, the operators should well understand the details of the apparatus including the recent change of design. This report describes outlines of the VEGA apparatus and the procedures for operation and maintenance. (author)

  10. Determination of the radionuclide release factor for an evaporator process using nondestructive assay

    International Nuclear Information System (INIS)

    Johnson, R.E.

    1998-01-01

    The 242-A Evaporator is the primary waste evaporator for the Hanford Site radioactive liquid waste stored in underground double-shell tanks. Low pressure evaporation is used to remove water from the waste, thus reducing the amount of tank space required for storage. The process produces a concentrated slurry, a process condensate, and an offgas. The offgas exhausts through two stages of high-efficiency particulate air (HEPA) filters before being discharged to the atmosphere 40 CFR 61 Subpart H requires assessment of the unfiltered exhaust to determine if continuous compliant sampling is required. Because potential (unfiltered) emissions are not measured, methods have been developed to estimate these emissions. One of the methods accepted by the Environmental Protection Agency is the measurement of the accumulation of radionuclides on the HEPA filters. Nondestructive assay (NDA) was selected for determining the accumulation on the HEPA filters. NDA was performed on the HEPA filters before and after a campaign in 1997. NDA results indicate that 2.1 E+4 becquerels of cesium-137 were accumulated on the primary HEPA 1700 filter during the campaign. The feed material processed in the campaign contained a total of 1.4 E+l6 Bq of cesium-137. The release factor for the evaporator process is 1.5 E-12. Based on this release factor, continuous compliant sampling is not required

  11. Radionuclides: Accumulation and Transport in Plants.

    Science.gov (United States)

    Gupta, D K; Chatterjee, S; Datta, S; Voronina, A V; Walther, C

    Application of radioactive elements or radionuclides for anthropogenic use is a widespread phenomenon nowadays. Radionuclides undergo radioactive decays releasing ionizing radiation like gamma ray(s) and/or alpha or beta particles that can displace electrons in the living matter (like in DNA) and disturb its function. Radionuclides are highly hazardous pollutants of considerable impact on the environment, food chain and human health. Cleaning up of the contaminated environment through plants is a promising technology where the rhizosphere may play an important role. Plants belonging to the families of Brassicaceae, Papilionaceae, Caryophyllaceae, Poaceae, and Asteraceae are most important in this respect and offer the largest potential for heavy metal phytoremediation. Plants like Lactuca sativa L., Silybum marianum Gaertn., Centaurea cyanus L., Carthamus tinctorius L., Helianthus annuus and H. tuberosus are also important plants for heavy metal phytoremediation. However, transfer factors (TF) of radionuclide from soil/water to plant ([Radionuclide]plant/[Radionuclide]soil) vary widely in different plants. Rhizosphere, rhizobacteria and varied metal transporters like NRAMP, ZIP families CDF, ATPases (HMAs) family like P1B-ATPases, are involved in the radio-phytoremediation processes. This review will discuss recent advancements and potential application of plants for radionuclide removal from the environment.

  12. Intervention procedures for radionuclides

    International Nuclear Information System (INIS)

    Adelstein, S.J.

    1991-01-01

    As in the case of smoking and lung cancer, for large radionuclide releases, an ounce of prevention is worth a pound of cure. On the other hand, we feel compelled to do something sensible after an accident even if the principal benefit of intervention may be to comfort the population at risk. Of course, for populations near the site of an accident, evacuation should be considered, but it is unreasonable to apply this measure to distant populations, e.g., large segments of the European community could not be moved about as we observe the shifting of a radioactive cloud in response to changing winds. If the radionuclides are delivered as particulates, bringing people indoors and employing primitive air filters can temporarily reduce exposures, but these stratagems are not very effective against gaseous or volatile elements. What, then, can be done for populations downwind of a radioactive release whose air, water, and/or food supply are, or are about to become contaminated? 5 refs

  13. Transfer factors for assessing the dose from radionuclides in agricultural products

    International Nuclear Information System (INIS)

    Ng, Y.C.; Colsher, C.S.; Thompson, S.E.

    1979-01-01

    Transfer factors to predict the environmental transport of radionuclides through terrestrial foodchains to man were derived from the literature for radionuclides associated with the nuclear fuel cycle. We present updated transfer coefficients to predict the concentration of a radionuclide in cow's milk and other animal products and concentration factors (CF) to predict the concentration in a food or feed crop from that in soil. Where possible we note the variation of the transfer factor with physical and chemical form of the radionuclide and environmental factors, and characterize the distribution and uncertainty in the estimate. The updated transfer factors are compared with those listed in regulatory guides. The new estimates lead to recommended changes (both increases and decreases) in the listed transfer coefficients for milk and meat and to the suggested practice of adopting multiple soil-to-plant CF's that vary with the type of crop and soil in the place of a single generic CF to predict the concentration of a radionuclide in a crop from that in soil. The updated transfer factors will be useful to assess the dose from radionuclides released from nuclear facilities and evaluating compliance with regulations governing the release of radionuclides

  14. Permissible annual depositions and radionuclide concentrations in air

    International Nuclear Information System (INIS)

    Belyaev, V.A.; Golovko, M.Yu.

    1993-01-01

    It is established that it necessary to take into account the other ways of radionuclide intake apart from the inhalation one when determining the standards for radionuclide contamination of the atmospheric air. Whereby it is proposed to standardize annual depositions rather than permissible concentration in the atmospheric air for the ways related to radionuclide releases on the ground surface, which is explained by ambiguity of their dry deposition rate from the air. Formulae and results of calculation of standard characteristics are presented. The permissible radionuclide depositions, related to the intake through food chains are calculated with account for diet diversity, agroclimatic and phenological parameters in different regions of the country

  15. Estimated airborne release of radionuclides from the Battelle Memorial Institute Columbus Laboratories JN-1b building at the West Jefferson site as a result of postulated damage from severe wind and earthquake hazard

    International Nuclear Information System (INIS)

    Mishima, J.; Ayer, J.E.

    1981-11-01

    The potential airborne releases of radionuclides (source terms) that could result from wind and earthquake dmage are estimated for the Battelle Memorial Institute Columbus Laboratories JN-1b Building at the West Jefferson site in Ohio. The estimated source terms are based on the damage to barriers containing the radionuclides, the inventory of radionuclides at risk, and the fraction of the inventory made airborne as a result of the loss of containment. In an attempt to provide a realistic range of potential source terms that include most of the normal operating conditions, a best estimate bounded by upper and lower limits is calculated by combining the upper-bound, best-estimate, and lower-bound inventories-at-risk with an airborne release factor (upper-bound, best-estimate, and lower-bound if possible) for the situation. The factors used to evaluate the fractional airborne release of materials and the exchange rates between enclosed and exterior atmospheres are discussed. The postulated damage and source terms are discussed for wind and earthquake hazard scenarios in order of their increasing severity

  16. Tumour control probability (TCP) for non-uniform activity distribution in radionuclide therapy

    International Nuclear Information System (INIS)

    Uusijaervi, Helena; Bernhardt, Peter; Forssell-Aronsson, Eva

    2008-01-01

    Non-uniform radionuclide distribution in tumours will lead to a non-uniform absorbed dose. The aim of this study was to investigate how tumour control probability (TCP) depends on the radionuclide distribution in the tumour, both macroscopically and at the subcellular level. The absorbed dose in the cell nuclei of tumours was calculated for 90 Y, 177 Lu, 103m Rh and 211 At. The radionuclides were uniformly distributed within the subcellular compartment and they were uniformly, normally or log-normally distributed among the cells in the tumour. When all cells contain the same amount of activity, the cumulated activities required for TCP = 0.99 (A-tilde TCP=0.99 ) were 1.5-2 and 2-3 times higher when the activity was distributed on the cell membrane compared to in the cell nucleus for 103m Rh and 211 At, respectively. TCP for 90 Y was not affected by different radionuclide distributions, whereas for 177 Lu, it was slightly affected when the radionuclide was in the nucleus. TCP for 103m Rh and 211 At were affected by different radionuclide distributions to a great extent when the radionuclides were in the cell nucleus and to lesser extents when the radionuclides were distributed on the cell membrane or in the cytoplasm. When the activity was distributed in the nucleus, A-tilde TCP=0.99 increased when the activity distribution became more heterogeneous for 103m Rh and 211 At, and the increase was large when the activity was normally distributed compared to log-normally distributed. When the activity was distributed on the cell membrane, A-tilde TCP=0.99 was not affected for 103m Rh and 211 At when the activity distribution became more heterogeneous. A-tilde TCP=0.99 for 90 Y and 177 Lu were not affected by different activity distributions, neither macroscopic nor subcellular

  17. Control of radioactive material transport in sodium-cooled reactors

    International Nuclear Information System (INIS)

    Brehm, W.F.

    1980-03-01

    The Radioactivity Control Technology (RCT) program was established by the Department of Energy to develop and demonstrate methods to control radionuclide transport to ex-core regions of sodium-cooled reactors. This radioactive material is contained within the reactor heat transport system with any release to the environment well below limits established by regulations. However, maintenance, repair, decontamination, and disposal operations potentially expose plant workers to radiation fields arising from radionuclides transported to primary system components. This paper deals with radioactive material generated and transported during steady-state operation, which remains after 24 Na decay. Potential release of radioactivity during postulated accident conditions is not discussed. The control methods for radionuclide transport, with emphasis on new information obtained since the last Environmental Control Symposium, are described. Development of control methods is an achievable goal

  18. Simulating Radionuclide Migrations of Low-level Wastes in Nearshore Environment

    Science.gov (United States)

    Lu, C. C.; Li, M. H.; Chen, J. S.; Yeh, G. T.

    2016-12-01

    Tunnel disposal into nearshore mountains was tentatively selected as one of final disposal sites for low-level wastes in Taiwan. Safety assessment on radionuclide migrations in far-filed may involve geosphere processes under coastal environments and into nearshore ocean. In this study the 3-D HYDROFEOCHE5.6 numerical model was used to perform simulations of groundwater flow and radionuclide transport with decay chains. Domain of interest on the surface includes nearby watersheds delineated by digital elevation models and nearshore seabed. As deep as 800 m below the surface and 400 m below sea bed were considered for simulations. The disposal site was located at 200m below the surface. Release rates of radionuclides from near-field was estimated by analytical solutions of radionuclide diffusion with decay out of engineered barriers. Far-field safety assessments were performed starting from the release of radionuclides out of engineered barriers to a time scale of 10,000 years. Sensitivity analyses of geosphere and transport parameters were performed to improve our understanding of safety on final disposal of low-level waste in nearshore environments.

  19. The release of organic material from clay based buffer materials and its potential implications for radionuclide transport

    International Nuclear Information System (INIS)

    Vilks, P.; Stroes-Gascoyne, S.; Goulard, M.; Haveman, S.A.; Bachinski, D.B.

    1998-01-01

    In the Canadian nuclear fuel waste disposal concept used fuel would be placed in corrosion resistant containers which would be surrounded by clay-based buffer and backfill materials in an engineered vault excavated at 500 to 1000 m depth in crystalline rock formations in the Canadian shield. Organic substances could affect radionuclide mobility due to the effects of redox and complexation reactions that increase solubility and alter mobility. The purpose of this study was to determine whether the buffer and backfill materials, proposed for use in a disposal vault, contain organics that could be leached by groundwater in large enough quantities to affect radionuclide mobility within the disposal vault and surrounding geosphere complex. Buffer material, made from a mixture of 50 wt.% Avonlea sodium bentonite and 50 wt.% silica sand, was extracted with deionized water to determine the release of dissolved organic carbon (DOC), humic acid and fulvic acid. The effect of radiation and heat from the used fuel was simulated by treating samples of buffer before leaching to various amounts of heat (60 and 90 C) for periods of 2, 4 and 6 weeks, and to ionizing radiation with doses of 25 kGy and 50 kGy. The results showed that groundwater would leach significant amounts of organics from buffer that complex with radionuclides such as the actinides, potentially affecting their solubility and transport within the disposal vault and possibly the surrounding geosphere. In addition, the leached organics would likely stimulate microbial growth by several orders of magnitude. Heating and radiation affect the amount and nature of leachable organics. (orig.)

  20. Assessment of impact of a severe accident at nuclear power plant of Angra dos Reis with release of radionuclides to the atmosphere

    International Nuclear Information System (INIS)

    Aguiar, Andre Silva de

    2015-01-01

    This study had as purpose the assess the impact of a severe accident, and also analyze the dispersion of 131 I in the atmosphere, so that, through concentrating and inhaling dose of the plume, were possible to verify if the results are in accordance with the indicated data by the Plan of Emergency of the CNAAA regarding the Impact Zone and Control. This exercise was performed with the aid of an atmospheric model and a dispersion where to atmospheric modeling we used the data coupling WRF / CALMET and of dispersion, CALPUFF. The suggested accident consists of a Station Blackout at Nuclear Power of Angra (Unit 1), where through the total core involvement, will release 100% of the 131 I to the atmosphere. The value of the total activity in the nucleus to this radionuclide is 7.44 x 1017 Bq, that is relative on the sixth day of burning. This activity will be released through the chimney at a rate in Bq/s in the scenario of 12, 24, 48 and 72 hours of release. Applying the model in the proposed scenario, it is verified that the plume has concentrations of the order of 1020 Bq/m³ and dose of about 108 Sv whose value is beyond of the presented by Eletronuclear in your current emergency plan. (author)

  1. Workload Control with Continuous Release

    NARCIS (Netherlands)

    Phan, B. S. Nguyen; Land, M. J.; Gaalman, G. J. C.

    2009-01-01

    Workload Control (WLC) is a production planning and control concept which is suitable for the needs of make-to-order job shops. Release decisions based on the workload norms form the core of the concept. This paper develops continuous time WLC release variants and investigates their due date

  2. EBS Radionuclide Transport Abstraction

    International Nuclear Information System (INIS)

    Schreiner, R.

    2001-01-01

    The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M and O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to as the ''EBS RT Abstraction'' in this analysis/modeling report (AMR). The scope of this abstraction and report is limited to flow and transport processes. More specifically, this AMR does not discuss elements of the TSPA-SR and TSPA-LA that relate to the EBS but are discussed in other AMRs. These elements include corrosion processes, radionuclide solubility limits, waste form dissolution rates and concentrations of colloidal particles that are generally represented as boundary conditions or input parameters for the EBS RT Abstraction. In effect, this AMR provides the algorithms for transporting radionuclides using the flow geometry and radionuclide concentrations determined by other

  3. Possibility of removing radionuclides in landfill leachate using advanced wastewater treatment processes

    International Nuclear Information System (INIS)

    Ishikawa, Nao K.; Umita, Teruyuki; Ito, Ayumi

    2013-01-01

    Radionuclides released by the nuclear accident at the Fukushima Daiichi Nuclear Power Plant are being partly concentrated to sewage sludge ash and waste ash. These ashes, in which radiocesium concentration is lower than 8000 Bq/kg, are being disposed of in a controlled landfill site. The leachate from the landfill site is treated in a leachate treatment system combined with some treatment steps before it is discharged into receiving water. In this study, in place of radionuclides, stable element concentrations in the leachate and treated water at each treatment step were measured to estimate the possible extent of radionuclide removal from the leachate step-by-step. It was found that Cs was not removed in any treatment steps, while more than 85% of the Sr, Co, Ni, and Mn present was removed in the alkaline earth element removal step. (author)

  4. Review Paper of Radionuclide Monitoring in Food Sample

    International Nuclear Information System (INIS)

    Noor Fadzilah Yusof; Abdul Kadir Ishak; Wo, Y.M.; Nurrul Assyikeen Mohd Jaffary

    2011-01-01

    The uncontrolled release of radionuclides into the atmospheric and aquatic environments may occur as the result of a nuclear or radiological accident. Monitoring of the accidental release at its source and especially direct monitoring of the environmental contamination with radionuclides is necessary for assessment and application of public protective actions and longer term countermeasures as well as emergency workers' protection. In areas historically contaminated with long lived radionuclides monitoring it is essential to protect the public and substantiation of any radiological incidents. Also, dietary pathways can be contaminated with radioactive materials resulting from natural occurrence or man-made applications especially during routine operation, accidents and migration of radionuclides from radioactive waste disposal repositories into the biosphere. Therefore, efforts should be made to determine the presence of radionuclides in a potentially high radiation area especially in operational nuclear facilities. This paper will review the strategies for food monitoring that has been adapted in most countries to obtain baseline data for future reference. Also, this study is discussing the type of food selection commonly collected as sample for radionuclide analysis in different countries over the years. Sampling procedure and analysis also included in this review for better understanding of the analysis. Stake holders' involvement is considered as an important asset in the establishment of monitoring strategies. As a conclusion, future plans for food monitoring programme in Malaysia are recommended as a preparation to embark on the Nuclear Power Plant programme. (author)

  5. Application of radionuclide infarct scintigraphy to diagnose perioperative myocardial infarction following revascularization

    International Nuclear Information System (INIS)

    Klausner, S.C.; Botvinick, E.H.; Shames, D.; Ullyot, D.J.; Fishman, N.H.; Roe, B.B.; Ebert, P.A.; Chatterjee, K.; Parmley, W.W.

    1977-01-01

    To evaluate the application of radionuclide infarct scintigraphy to diagnose myocardial infarction after revascularization, we obtained postoperative technetium 99m pyrophosphate myocardial scintigrams, serial electrocardiograms and CPK-MB isoenzymes in ten control and 51 revascularized patients. All control patients had negative electrocardiograms and scintigrams, but eight had positive isoenzymes. Eight revascularized patients had positive electrocardiograms, images and enzymes and two had positive scintigrams and enzymes with negative electrocardiograms. Thirty-four patients with negative electrocardiograms and scintigrams had positive isoenzymes; in only seven patients were all tests negative. Our data suggest radionuclide infarct scintigraphy is a useful adjunct to the electrocardiogram in diagnosing perioperative infarction. The frequent presence of CPK-MB in postoperative patients without other evidence of infarction suggests that further studies are required to identify all factors responsible for its release

  6. Guidelines for agricultural countermeasures following an accidental release of radionuclides

    International Nuclear Information System (INIS)

    1994-01-01

    The Chernobyl accident in 1986 caused significant radioactive contamination of the environment over widely separated areas, some relatively remote from the site. Considerable scientific research was stimulated directly and indirectly and a good deal of practical experience was obtained in dealing with the aftermath. The collation of the relevant information and experience concerning the transfer of radionuclides through food chains and ways of reducing this transfer is a prudent insurance for the management of agriculture should a major nuclear accident occur again. Work to this end was begun in 1990 by a consultants group convened in a co-ordinated research programme of the IAEA and the CEC on the Validation of Models for the Transfer of Radionuclides in Terrestrial, Urban and Aquatic Environments (VAMP). The work was further developed by a joint programme of the IAEA Division of Nuclear Safety and the Agrochemicals and Residues Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture entitled ''Alleviating the Adverse Effects of Excessive Radionuclide Contamination of the Agricultural Environment''. The present Guidelines are an output of this programme and are intended to assist those charged with administrative, scientific and advisory responsibilities to prepare more detail plans specific to the local conditions. 80 refs, 1 fig., 20 tabs

  7. Controlled Release from Recombinant Polymers

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-01-01

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

  8. Simulation of radionuclide transfer in agricultural food chains

    International Nuclear Information System (INIS)

    Matthies, M.; Eisfeld, K.; Mueller, H.; Paretzke, H.G.; Proehl, G.; Wirth, E.

    1982-12-01

    Radioactive releases from nuclear facilities could pose longterm potential hazards to man if radionuclides enter food chains leading to man. The aim of the study was to develop radioecological and dosimetric models for the assessments of the activity intake by man via ingestion and the resulting radiation exposure for members of the population, in particular after accidental releases from fuel reprocessing plants and related installations. A dynamic compartment model for the transfer of radionuclides through agricultural food chains has been developed. Special emphasis is given to the time dependence and the biological and site specific variability of the various transfer and accumulation processes. Agricultural practices representative for Western Europe have been taken into consideration for food production (grain, potatoes, vegetables, beef and pork, milk). For the most relevant long-lived radionuclides a short-term initial deposition of 1 Ci/km 2 on agricultural areas at different months has been assumed and the time dependent transport through various food chains has been assessed. As a main result great differences have been calculated for the various months of releases because of plant foliar uptake and translocation into edible parts of the plants during the vegetation cycle. The potential activity intake over 50 years for the various nuclides and the resulting radiation exposure is dominated by the first two years after the release if no food restrictions are assumed. (orig./MG) [de

  9. New approaches to deriving limits of the release of radioactive material into the environment

    International Nuclear Information System (INIS)

    Lindell, B.

    1977-01-01

    During the last few years, new principles have been developed for the limitation of the release of radioactive material into the environment. It is no longer considered appropriate to base the limitation on limits for the concentrations of the various radionuclides in air and water effluents. Such limits would not prevent large amounts of radioactive material from reaching the environment should effluent rates be high. A common practice has been to identify critical radionuclides and critical pathways and to base the limitation on authorized dose limits for local ''critical groups''. If this were the only limitation, however, larger releases could be permitted after installing either higher stacks or equipment to retain the more short-lived radionuclides for decay before release. Continued release at such limits would then lead to considerably higher exposure at a distance than if no such installation had been made. Accordingly there would be no immediate control of overlapping exposures from several sources, nor would the system guarantee control of the future situation. The new principles described in this paper take the future into account by limiting the annual dose commitments rather than the annual doses. They also offer means of controlling the global situation by limiting not only doses in critical groups but also global collective doses. Their objective is not only to ensure that individual dose limits will always be respected but also to meet the requirement that ''all doses be kept as low as reasonably achievable''. The new approach is based on the most recent recommendations by the ICRP and has been described in a report by an IAEA panel (Procedures for establishing limits for the release of radioactive material into the environment). It has been applied in the development of new Swedish release regulations, which illustrate some of the problems which arise in the practical application

  10. New approaches to deriving limits of the release of radioactive material into the environment

    International Nuclear Information System (INIS)

    Lindell, B.

    1977-01-01

    During the last few years, new principles have been developed for the limitation of the release of radioactive material into the environment. It is no longer considered appropriate to base the limitation on limits for the concentrations of the various radionuclides in air and water effluents. Such limits would not prevent large amounts of radioactive material from reaching the environment should effluent rates be high. A common practice has been to identify critical radionuclides and critical pathways and to base the limitation on authorized dose limits for local ''critical groups''. If this were the only limitation, however, larger releases could be permitted after installing either higher stacks or equipment to retain the more shortlived radionuclides for decay before release. Continued release at such limits would then lead to considerably higher exposure at a distance than if no such installation had been made. Accordingly there would be no immediate control of overlapping exposures from several sources, nor would the system guarantee control of the future situation. The new principles described in this paper take the future into account by limiting the annual dose commitments rather than the annual doses. They also offer means of controlling the global situation by limiting not only doses in critical groups but also global collective doses. Their objective is not only to ensure that individual dose limits will always be respected but also to meet the requirement that ''all doses be kept as low as reasonably achievable''. The new approach is based on the most recent recommendations by the ICRP and has been described in a report by an IAEA panel (Procedures for Establishing Limits for the Release of Radioactive Material into the Environment). It has been applied in the development of new Swedish release regulations, which illustrate some of the problems which arise in the practical application. (author)

  11. Derived release limits for airborne effluents at TRIGA - INR Reactor

    International Nuclear Information System (INIS)

    Toma, A.; Dulama, C.; Hirica, O.; Mihai, S.; Oprea, I.

    2008-01-01

    Beginning from fulfilling the purposes of dose limitation system recommended by ICRP, and now accepted in radiation protection, this paper presents an environmental transfer model to calculate derived release limits for airborne and gaseous radioactive effluents at TRIGA-INR, 14 MW Steady State Reactor, in function on INR-Pitesti site. The methodology consists in determination of the principal exposure pathways for different groups of population and dose calculations for each radionuclide. The characterization of radionuclides transfer to environment was made using the compartmental model. The parameter transfer concept was used to describe the distribution of radionuclides between the different compartments. Atmospheric dispersion was very carefully treated, because it is the primary mechanism of the transfer of radionuclides in the environment and it determines all exposure pathways. Calculation of the atmospheric dispersion was made using ORION-II computer code based on the Gaussian plume model which takes account of site's specific climate and relief conditions. Default values recommended by literature were used to calculate some of the parameters when specific site values were not available. After identification of all transfer parameters which characterize the most important exposure pathways, the release rate corresponding to the individual dose rate limit was calculated. This maximum release rate is the derived release limit for each radionuclide and source. In the paper, the derived release limits are calculated for noble gases, radioiodine and other airborne particulate radionuclides, which can be released on the TRIGA-INR reactor stack, and are important to radiation protection. (authors)

  12. Transfer of radionuclides into human milk

    International Nuclear Information System (INIS)

    Steiner, M.; Wirth, E.

    1998-01-01

    Up until now the potential radiation exposure to breast-fed babies due to contaminated human milk has not been taken into account, when deriving international limit values and reference levels for radionuclides in foodstuffs, in air at monitored work places or for exposures in the medical field. It was the aim of the research project 'Transfer of radionuclides into human milk' to quantify the transfer of incorporated radionuclides into mother's milk, and develop simple models to estimate the radiation exposure of babies through the ingestion of human milk. The study focused on considerations of the radiation exposure due to the ingestion of contaminated foodstuffs by the mother, the inhalation of radionuclides at monitored work places, and the administration of radiopharmaceuticals to breast-feeding mothers. The blocking of infant thyroid glands by stable iodine in the case of accidental releases of radioiodine was considered as well. (orig.) [de

  13. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 4. Releases to the biosphere of radionuclides from underground nuclear weapon tests at the atolls

    International Nuclear Information System (INIS)

    1998-08-01

    This report is Volume 4 in the series of 6 volumes of the Technical Report on the radiological situation at the atolls of Mururoa and the Fangataufa. It is the second of the three volumes dealing with the evaluation of the long term radiological situation as a consequence of radionuclide migration from underground sources, which is the responsibility of Task Group B. This volume is based on the activities of Working Group 4 and uses, as its primary input on radionuclide inventories the report of Working Group 3, which is Vol. 3 in this series of Technical Report. Nuclear testing in the atmosphere, outer space and under open ocean was prohibited by the Limited Test Ban Treaty of 5 August 1963 and signed by UK, USA and USSR. France ceased atmospheric testing in September 1974. Isolation from the biosphere in geological formations, or containment in geological formations, became the preferred alternative. The explosion of 137 underground nuclear devices in Mururoa and Fangataufa over the testing period 1975-1996, together with 10 safety trials and the burial of radioactively contaminated material gathered from the atoll surfaces, has resulted in a substantial accumulation of radionuclides in the rock beneath the two atolls. Assessment of the rate at which these radionuclides move from the cavities to the environment accessible to humans, or biosphere and the total radionuclide release to the biosphere over time is the central effort of this Study. The rock mass within which the radionuclides are initially deposited, and which serves to contain or delay release of the radionuclides, will be referred to as the geosphere to distinguish it from the biosphere, where the radionuclides would be accessible either directly or through the food chain to the living environment. This assessment of geosphere transport has been divided into the following four interrelated tasks: (a) Geological Pathways; (b) Hydrological Modelling; (c) Solution Source Term; and (d) Geosphere

  14. Release and transport of artificial radionuclides from nuclear weapons related activities in the Ob River, Siberia over the course of the nuclear age

    International Nuclear Information System (INIS)

    Sayles, F.L.; Kenna, T.C.; Livingston, H.D.

    1999-01-01

    Studies of sediment cores from lakes on the flood plain of the Ob River, Siberia have been used to develop a history of the release, transport, and deposition of artificial radionuclides related to the development and testing of nuclear weapons over the duration of the nuclear age (∼1950 to the present) in this major Arctic river system. The Ob is of particular importance in this regard as two of the former Soviet Union's major weapons production plants, Mayak and Tomsk-7, and the Semipalatinsk test site are located within the Ob drainage basin. Accidents and intentional releases of radionuclides at both plants have been substantial, raising the issue of transport throughout this extensive river system as well as delivery to the Arctic Ocean. Our studies have included determining sediment profiles of 239,240 Pu, 137 Cs, and the natural nuclide 210 Pb and its parent 226 Ra in a number of cores from the Ob delta, as well as analysis of 239 Pu, 240 Pu, and 237 Np. The latter provide sensitive measures of the presence of non-fallout materials derived from weapons production activities

  15. BIODOSE: a code for predicting the dose to man from radionuclides released from underground nuclear waste repositories

    International Nuclear Information System (INIS)

    Bonner, N.A.; Ng, Y.C.

    1980-03-01

    The BIODOSE computer program simulates the environmental transport of radionuclides released to surface water and predicts the resulting dosage to humans. This report describes the program and discusses its use in the evaluation of nuclear waste repositories. The methods used to estimate dose are examined critically, and the most important parameters in each stage of the calculations are identified as an aid in planning for measurements in the field. Dose predictions from releases of nuclear waste to a large northwestern river (the baseline river) are presented to point out the nuclides, compartments and pathways that contribute most to the hazard as a function of waste storage time. Predictions for five other water systems are presented to identify the most important system parameters that determine the concentrations of individual nuclides in compartments and the resultant dose. The uncertainties in the biological parameters for dose prediction are identified, and changes in current values are suggested. Various ways of reporting dose estimates for radiological safety assessments are discussed. Additional work needed to improve the dose predictions from BIODOSE and specific areas and steps to improve our capabilities to assess the environmental transport of nuclides released from nuclear waste repositories and the resultant dose to man are suggested

  16. Hydrology and Radionuclide Migration Program: 1989 progress report

    International Nuclear Information System (INIS)

    Marsh, K.V.

    1992-08-01

    This report presents results from the Lawrence Livermore National Laboratory's participation in the Hydrology and Radionuclide Migration Program (HRMP) at the Nevada Test Site (NTS) during fiscal year 1989. The report compares and summarizes studies of radionuclide and stable element transport atf radionuclide and stable the Cheshire and Cambric sites; progress toward the understanding of colloidal particle transport in porous and fractured media; further calibration of Marinelli beaker containers for gamma-ray spectroscopy; and an appendix listing all announced tests fired near the water table through October 1989. Four such tests were fired in FY89. Laboratory and model investigations of colloid transport in porous and fractured media have supported ongoing field investigations at the NTS. Aqueous chemistry has been shown to control colloid attachment and release from clean mineral surfaces. For colloidal deposits on fracture walls, the current experimental program will determine how this material responds to hydrodynamic forcing and if the porous colloidal deposit causes the more rapid transport of colloids than non-sorbing tracers. Fifteen radionuclides are either frequently found or likely to be found in HRMP and other environmental samples. For 3 of these 15 we have calibrated 4 gamma-ray detectors for use with samples contained in Marinelli beakers. Our calibrations for these three nuclides indicate that the technique is accurate and applicable to the types of environmental samples that we analyze

  17. Pacific Northwest National Laboratory Facility Radionuclide Emission Points and Sampling Systems

    International Nuclear Information System (INIS)

    Barfuss, Brad C.; Barnett, J. M.; Ballinger, Marcel Y.

    2009-01-01

    Battelle-Pacific Northwest Division operates numerous research and development laboratories in Richland, Washington, including those associated with the Pacific Northwest National Laboratory (PNNL) on the Department of Energy's Hanford Site that have the potential for radionuclide air emissions. The National Emission Standard for Hazardous Air Pollutants (NESHAP 40 CFR 61, Subparts H and I) requires an assessment of all effluent release points that have the potential for radionuclide emissions. Potential emissions are assessed annually. Sampling, monitoring, and other regulatory compliance requirements are designated based upon the potential-to-emit dose criteria found in the regulations. The purpose of this document is to describe the facility radionuclide air emission sampling program and provide current and historical facility emission point system performance, operation, and design information. A description of the buildings, exhaust points, control technologies, and sample extraction details is provided for each registered or deregistered facility emission point. Additionally, applicable stack sampler configuration drawings, figures, and photographs are provided

  18. Pacific Northwest National Laboratory Facility Radionuclide Emission Points and Sampling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Barfuss, Brad C.; Barnett, J. Matthew; Ballinger, Marcel Y.

    2009-04-08

    Battelle—Pacific Northwest Division operates numerous research and development laboratories in Richland, Washington, including those associated with the Pacific Northwest National Laboratory (PNNL) on the Department of Energy’s Hanford Site that have the potential for radionuclide air emissions. The National Emission Standard for Hazardous Air Pollutants (NESHAP 40 CFR 61, Subparts H and I) requires an assessment of all effluent release points that have the potential for radionuclide emissions. Potential emissions are assessed annually. Sampling, monitoring, and other regulatory compliance requirements are designated based upon the potential-to-emit dose criteria found in the regulations. The purpose of this document is to describe the facility radionuclide air emission sampling program and provide current and historical facility emission point system performance, operation, and design information. A description of the buildings, exhaust points, control technologies, and sample extraction details is provided for each registered or deregistered facility emission point. Additionally, applicable stack sampler configuration drawings, figures, and photographs are provided.

  19. Screening models for releases of radionuclides to atmosphere, surface water, and ground -- Work sheets

    International Nuclear Information System (INIS)

    1996-01-01

    Three levels of screening for the atmospheric transport pathways and two levels for surface water are presented. The ground has only one screening level. Level 1 is the simplest approach and incorporates a high degree of conservatism. The estimate of the effective dose for this level assumes a concentration based upon the radionuclide concentration at the point of emission to the environment, i.e., at the stack for atmospheric emissions, at the end of the effluent pipe for liquid effluent releases, and at a well because of the buried radioactive material. Levels 2 and 3 are presented for atmospheric releases, and Level 2 for surface water releases only and are more detailed and correspondingly less conservative. Level 2 screening accounts for dispersion in the atmosphere and in surface waters and combines all recognized pathways into the screening factor. For the atmospheric pathway, Level 3 screening includes more definitive pathways analysis. Should the user be found in compliance on the basis of Level 1 screening, no further calculations are required. If the user fails Level 1, the user proceeds to the next level and checks for compliance. This process is repeated until the user passes screening (is in compliance) or no further screening levels exist. If the user fails the final level, professional assistance should be obtained in environmental radiological assessment. Work sheets are designed to lead the user through screening in a step-by-step manner until compliance is demonstrated or it is determined that more sophisticated methods or expertise are needed. Flow diagrams are provided as a guide to identify key steps in the screening process

  20. Scenarios for long-term release of radionuclides from a nuclear-waste repository in the Los Medanos region of New Mexico

    International Nuclear Information System (INIS)

    Bingham, F.W.; Barr, G.E.

    1979-05-01

    This report discusses hypothetical sequences of events that could conceivably release radionuclides from radioactive waste buried in the proposed WIPP repository. All the scenarios are described in terms specific to the WIPP site; they include only events whose occurrence is physically possible there. The report estimates the relative probabilities of the scenarios at times ranging from 1000 to 1 million years after the repository is sealed. Although none of the scenarios is judged likely, the report recommends several for detailed computer modeling and consequence analysis

  1. Application of innovative policies for controlling radionuclide releases: The {open_quotes}open-market trading rule{close_quotes}

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, D.W. [Dade Moeller & Associates, Inc., New Bern, NC (United States)

    1997-08-01

    In the past, most efforts for reducing airborne radio nuclide releases and controlling radioactive wastes have been directed to the development of new and improved technologies. Little attention has been paid to the possible application to these problems of new, innovative policies. Yet, experience in other fields shows that such applications could be beneficial. A prime example is the {open_quotes}open-market trading rule,{close_quotes} now being widely used in the U.S. for the control of a range of environmental problems. Through this rule, nuclear facility operators would be permitted to control airborne emissions in a more cost-effective manner, and those responsible for decommissioning and decontaminating nuclear facilities no longer in operation could do so at far lower costs while generating significantly smaller volumes of radioactive wastes. Application of such a policy would also significantly reduce the demands on existing, and the need for research to develop new, improved, control technologies. 16 refs.

  2. Controlled drug release for tissue engineering.

    Science.gov (United States)

    Rambhia, Kunal J; Ma, Peter X

    2015-12-10

    Tissue engineering is often referred to as a three-pronged discipline, with each prong corresponding to 1) a 3D material matrix (scaffold), 2) drugs that act on molecular signaling, and 3) regenerative living cells. Herein we focus on reviewing advances in controlled release of drugs from tissue engineering platforms. This review addresses advances in hydrogels and porous scaffolds that are synthesized from natural materials and synthetic polymers for the purposes of controlled release in tissue engineering. We pay special attention to efforts to reduce the burst release effect and to provide sustained and long-term release. Finally, novel approaches to controlled release are described, including devices that allow for pulsatile and sequential delivery. In addition to recent advances, limitations of current approaches and areas of further research are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Impact of Storage Time on the Needed Capture Efficiency for Volatile Radionuclides - 13369

    Energy Technology Data Exchange (ETDEWEB)

    Jubin, R.T.; Ilas, G. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37849 (United States); Soelberg, N.R. [Idaho National Laboratory (United States); Strachan, D.M. [Pacific Northwest National Laboratory (United States)

    2013-07-01

    During the processing of used nuclear fuel (UNF), volatile radionuclides will be discharged from the facility stack if no recovery processes are in place to limit their release. The volatile radionuclides of concern are {sup 3}H, {sup 14}C, {sup 85}Kr, and {sup 129}I. There are three key regulations that address the release of these radionuclides to the environment- 40 CFR 61, 40 CFR 190, and 10 CFR 20. These regulations apply to the total radionuclide release and establish dose limits for the maximum exposed individual (MEI) in the public both in terms of whole body dose and dose to specific organs such as the thyroid. Each radionuclide released to the environment contributes to the total dose to some degree. In this paper we attempt to evaluate the efficiency requirements for the capture processes to limit the doses to the MEI to regulatory levels. Since the total amount of each volatile radionuclide present in the UNF changes with the age of the fuel, the respective capture requirements also change with time. Specifically, we are interested in the impact of the decreasing contribution of {sup 3}H and {sup 85}Kr, which have relatively short half-lives, 12.32 y and 10.76 y, respectively, with the increasing age of the fuel (i.e., time between when the UNF is removed from the reactor and the time it is processed) on the capture requirements. In this paper we examine the capture requirements for these four radionuclides for three fuel types (pressurized water reactor [PWR] with uranium oxide fuel [UOX], PWR with mixed oxide fuel [MOX], and an advanced high temperature gas-cooled reactor [AHTGR]), several burnup values, and time out of reactor extending to 200 y. We calculate doses to the MEI with the EPA code CAP-88 and look at two dose contribution cases. In the first case, we assume that the total allowable dose is attributed to only the four volatile radionuclides. This establishes the lowest capture efficiency value possible. Since this is unrealistic, because

  4. Behaviour and control of radionuclides in the environment: present state of knowledge and future needs

    International Nuclear Information System (INIS)

    Myttenaere, C.

    1983-01-01

    The Radiation Protection Programme of the European Communities is discussed in the context of the behaviour and control of radionuclides in the environment with reference to the aims of the programme, the results of current research activities and requirements for future studies. The summarised results of the radioecological research activities for 1976 - 1980 include the behaviour of α-emitters (Pu, Am, Cm), 99 Tc, 137 Cs, 144 Ce, 106 Ru and 125 Sb in marine environments; atmospheric dispersion of radionuclides; and the transport of radionuclides in components of freshwater and terrestrial ecosystems. (U.K.)

  5. Deposition of radionuclides and their subsequent relocation in the environment following an accidental release to the atmosphere

    International Nuclear Information System (INIS)

    Underwood, B.Y.; Roed, J.; Paretzke, H.G.

    1993-01-01

    The objective of the project is to improve, as necessary, the models and parameterizations used in estimating the intensity and spatial distribution of deposited activity, and the total health/economic impact of such deposits in assessments of the consequences of accidental releases of radioactivity. The study comprises the influence of various weather conditions on deposition; the resuspension of deposited 137 Cs activity; the weathering of deposits in urban and rural environments; the ultimate fate and dosimetric impact of radionuclides carried by urban run-off water; the impact of the atmosphere's dispersion capabilities. Objectives and results of the four contributions to the project for the reporting period are presented. (R.P.) 5 refs., 4 figs., 1 tab

  6. One-dimensional radionuclide transport under time-varying conditions

    International Nuclear Information System (INIS)

    Gelbard, F.; Olague, N.E.; Longsine, D.E.

    1990-01-01

    This paper discusses new analytical and numerical solutions presented for one-dimensional radionuclide transport under time-varying fluid-flow conditions including radioactive decay. The analytical solution assumes that all radionuclides have identical retardation factors, and is limited to instantaneous releases. The numerical solution does not have these limitations, but is tested against the limiting case given for the analytical solution. Reasonable agreement between the two solutions was found. Examples are given for the transport of a three-member radionuclide chain transported over distances and flow rates comparable to those reported for Yucca Mountain, the proposed disposal site for high-level nuclear waste

  7. Hanford Waste Vitrification Plant technical background document for best available radionuclide control technology demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, A.B.; Skone, S.S.; Rodenhizer, D.G.; Marusich, M.V. (Ebasco Services, Inc., Bellevue, WA (USA))

    1990-10-01

    This report provides the background documentation to support applications for approval to construct and operate new radionuclide emission sources at the Hanford Waste Vitrification Plant (HWVP) near Richland, Washington. The HWVP is required to obtain permits under federal and state statutes for atmospheric discharges of radionuclides. Since these permits must be issued prior to construction of the facility, draft permit applications are being prepared, as well as documentation to support these permits. This report addresses the applicable requirements and demonstrates that the preferred design meets energy, environmental, and economic criteria for Best Available Radionuclide Control Technology (BARCT) at HWVP. 22 refs., 11 figs., 25 tabs.

  8. Hanford Waste Vitrification Plant technical background document for best available radionuclide control technology demonstration

    International Nuclear Information System (INIS)

    Carpenter, A.B.; Skone, S.S.; Rodenhizer, D.G.; Marusich, M.V.

    1990-10-01

    This report provides the background documentation to support applications for approval to construct and operate new radionuclide emission sources at the Hanford Waste Vitrification Plant (HWVP) near Richland, Washington. The HWVP is required to obtain permits under federal and state statutes for atmospheric discharges of radionuclides. Since these permits must be issued prior to construction of the facility, draft permit applications are being prepared, as well as documentation to support these permits. This report addresses the applicable requirements and demonstrates that the preferred design meets energy, environmental, and economic criteria for Best Available Radionuclide Control Technology (BARCT) at HWVP. 22 refs., 11 figs., 25 tabs

  9. Local control of striatal dopamine release

    Directory of Open Access Journals (Sweden)

    Roger eCachope

    2014-05-01

    Full Text Available The mesolimbic and nigrostriatal dopamine (DA systems play a key role in the physiology of reward seeking, motivation and motor control. Importantly, they are also involved in the pathophysiology of Parkinson’s and Huntington’s disease, schizophrenia and addiction. Control of DA release in the striatum is tightly linked to firing of DA neurons in the ventral tegmental area (VTA and the substantia nigra (SN. However, local influences in the striatum affect release by exerting their action directly on axon terminals. For example, endogenous glutamatergic and cholinergic activity is sufficient to trigger striatal DA release independently of cell body firing. Recent developments involving genetic manipulation, pharmacological selectivity or selective stimulation have allowed for better characterization of these phenomena. Such termino-terminal forms of control of DA release transform considerably our understanding of the mesolimbic and nigrostriatal systems, and have strong implications as potential mechanisms to modify impaired control of DA release in the diseased brain. Here, we review these and related mechanisms and their implications in the physiology of ascending DA systems.

  10. SR 97 - Radionuclide transport calculations

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, Maria [Kemakta Konsult AB, Stockholm (Sweden); Lindstroem, Fredrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1999-12-01

    values. In that case almost all radionuclides will be contained in the near field. The dose rate in the biosphere is essentially controlled by the possibilities of dilution. If the release occurs to an inner bay or open coast, the dose rates will be several orders of magnitude lower than if the release occurs to a drinking water well or peat area.

  11. SR 97 - Radionuclide transport calculations

    International Nuclear Information System (INIS)

    Lindgren, Maria; Lindstroem, Fredrik

    1999-12-01

    radionuclides will be contained in the near field. The dose rate in the biosphere is essentially controlled by the possibilities of dilution. If the release occurs to an inner bay or open coast, the dose rates will be several orders of magnitude lower than if the release occurs to a drinking water well or peat area

  12. The separation of radionuclide migration by solution and particle transport in LLRW repository buffer material

    International Nuclear Information System (INIS)

    Torok, J.; Buckley, L.P.; Woods, B.L.

    1989-01-01

    Laboratory-scale lysimeter experiments were performed with simulated waste forms placed in candidate buffer materials which have been chosen for a low-level radioactive waste repository. Radionuclide releases into the effluent water and radionuclide capture by the buffer material were determined. The results could not be explained by traditional solution transport mechanisms, and transport by particles released from the waste form and/or transport by buffer particles were suspected as the dominant mechanism for radionuclide release from the lysimeters. To elucidate the relative contribution of particle and solution transport, the waste forms were replaced by a wafer of neutron-activated buffer soaked with selected soluble isotopes. Particle transport was determined by the movement of gamma-emitting neutron-activation products through the lysimeter. Solution transport was quantified by comparing the migration of soluble radionuclides relative to the transport of neutron activation products. The new approach for monitoring radionuclide migration in soil is presented. It facilitates the determination of most of the fundamental coefficients required to model the transport process

  13. Methods of Increasing the Performance of Radionuclide Generators Used in Nuclear Medicine: Daughter Nuclide Build-Up Optimisation, Elution-Purification-Concentration Integration, and Effective Control of Radionuclidic Purity

    Directory of Open Access Journals (Sweden)

    Van So Le

    2014-06-01

    Full Text Available Methods of increasing the performance of radionuclide generators used in nuclear medicine radiotherapy and SPECT/PET imaging were developed and detailed for 99Mo/99mTc and 68Ge/68Ga radionuclide generators as the cases. Optimisation methods of the daughter nuclide build-up versus stand-by time and/or specific activity using mean progress functions were developed for increasing the performance of radionuclide generators. As a result of this optimisation, the separation of the daughter nuclide from its parent one should be performed at a defined optimal time to avoid the deterioration in specific activity of the daughter nuclide and wasting stand-by time of the generator, while the daughter nuclide yield is maintained to a reasonably high extent. A new characteristic parameter of the formation-decay kinetics of parent/daughter nuclide system was found and effectively used in the practice of the generator production and utilisation. A method of “early elution schedule” was also developed for increasing the daughter nuclide production yield and specific radioactivity, thus saving the cost of the generator and improving the quality of the daughter radionuclide solution. These newly developed optimisation methods in combination with an integrated elution-purification-concentration system of radionuclide generators recently developed is the most suitable way to operate the generator effectively on the basis of economic use and improvement of purposely suitable quality and specific activity of the produced daughter radionuclides. All these features benefit the economic use of the generator, the improved quality of labelling/scan, and the lowered cost of nuclear medicine procedure. Besides, a new method of quality control protocol set-up for post-delivery test of radionuclidic purity has been developed based on the relationship between gamma ray spectrometric detection limit, required limit of impure radionuclide activity and its measurement

  14. Effects of Containment on Radionuclide Releases from Underground Nuclear Explosions

    Science.gov (United States)

    Carrigan, C. R.; Sun, Y.

    2016-12-01

    Confirming the occurrence of an underground nuclear explosion can require capturing short-lived noble gas radioisotopes produced by the explosion, sometimes referred to as the "smoking gun" for nuclear explosion detection. It is well known that the radioisotopic distribution resulting from the detonation evolves with time in the explosion cavity. In effect, the explosion cavity or chimney behaves as a chemical reactor. As long as the parent and daughter radionuclides remain in a closed and well-mixed cavity, parameters, such as radioxenon isotopic ratios, can be calculated analytically from a decay-chain network model. When gases from the cavity migrate into the containment regime, consideration of a "leaky reactor" model is more appropriate. We consider several implications of such a leaky reactor model relevant to interpretations of gas samples from the subsurface during an on-site inspection that could potentially be carried out under the Comprehensive Nuclear Test Ban Treaty. Additionally, we have attempted to validate our leaky reactor model against atmospheric observations of radioactive xenon isotopes detected by radionuclide monitoring stations in Japan and Russia following the February 2013 DPRK underground nuclear explosion (Carrigan et al., 2016). While both model uncertainty and observational error are significant, our model of isotopic evolution appears to be in broad agreement with radionuclide observations, and for the first time links atmospheric measurements of radioxenon isotopic ratios to estimates of seismic yield. Carrigan et al., Scientific Reports 6, Article number: 23032 (2016) doi:10.1038/srep23032

  15. Arrival of radionuclides released by the Fukushima accident to Tenerife (Canary Islands)

    International Nuclear Information System (INIS)

    López-Pérez, M.; Ramos-López, R.; Perestelo, Nayra R.; Duarte-Rodriguez, X.; Bustos, J.J.; Alonso-Pérez, S.; Cuevas, E.; Hernández-Armas, J.

    2013-01-01

    Two weeks after the accident at the Fukushima-Daichi nuclear power plant, 131I, 137Cs and 134Cs activities were measured in two different stations located in Tenerife (Canary Islands), situated at 300 (FIMERALL) and 2400 (IZAÑA) m.a.s.l, respectively. Peak measured activity concentrations were: 1.851 mBq/m3 (131I); 0.408 mBq/m3 (137Cs) and 0.382 mBq/m3 (134Cs). The activities measured at the FIMERALL station were always higher than at IZAÑA station, suggesting that the radioactive plume arrived to the island associated with low altitude air masses. Simulations of potential dispersion of the radioactive cloud (137Cs) after the nuclear accident in reactor Fukushima I show that radioactive pollution reached remote regions such as the Canary Islands in the Eastern subtropical North Atlantic. The corresponding effective dose to the local population was 1.17 nSv, a value less than one millionth of the annual limit for the general public. Therefore, there was no risk to public health. - Highlights: ► Arrival of radionuclides to Tenerife following the accident of Fukushima. ► The atmospheric concentration of radionuclides was always higher at low altitude. ► After reaching the peak concentration a sharp decrease of radionuclides was observed. ► Air mass forward trajectory analysis confirms the potential arrival of radionuclides to Tenerife.

  16. CRITICAL RADIONUCLIDE AND PATHWAY ANALYSIS FOR THE SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, T.

    2011-08-30

    This report is an update to the analysis, Assessment of SRS Radiological Liquid and Airborne Contaminants and Pathways, that was performed in 1997. An electronic version of this large original report is included in the attached CD to this report. During the operational history (1954 to the present) of the Savannah River Site (SRS), many different radionuclides have been released to the environment from the various production facilities. However, as will be shown by this updated radiological critical contaminant/critical pathway analysis, only a small number of the released radionuclides have been significant contributors to potential doses and risks to offsite people. The analysis covers radiological releases to the atmosphere and to surface waters, the principal media that carry contaminants offsite. These releases potentially result in exposure to offsite people. The groundwater monitoring performed at the site shows that an estimated 5 to 10% of SRS has been contaminated by radionuclides, no evidence exists from the extensive monitoring performed that groundwater contaminated with these constituents has migrated off the site (SRS 2011). Therefore, with the notable exception of radiological source terms originating from shallow surface water migration into site streams, onsite groundwater was not considered as a potential exposure pathway to offsite people. In addition, in response to the Department of Energy's (DOE) Order 435.1, several Performance Assessments (WSRC 2008; LWO 2009; SRR 2010; SRR 2011) and a Comprehensive SRS Composite Analysis (SRNO 2010) have recently been completed at SRS. The critical radionuclides and pathways identified in these extensive reports are discussed and, where applicable, included in this analysis.

  17. Regulatory Initiatives for Control and Release of Technologically Enhanced Naturally-Occurring Radioactive Material

    International Nuclear Information System (INIS)

    Egidi, P.V.

    1999-01-01

    Current drafts of proposed standards and suggested State regulations for control and release of technologically-enhanced naturally-occurring radioactive material (TENORM), and standards for release of volumetrically-contaminated material in the US are reviewed. These are compared to the recommendations of the International Atomic Energy Association (IAEA) Safety Series and the European Commission (EC) proposals. Past regulatory efforts with respect to TENORM in the US dealt primarily with oil-field related wastes. Currently, nine states (AK, GA, LA, MS, NM, OH, OR SC, TX) have specific regulations pertaining to TENORM, mostly based on uranium mill tailings cleanup criteria. The new US proposals are dose- or risk-based, as are the IAEA and EC recommendations, and are grounded in the linear no threshold hypothesis (LNT). TENORM wastes involve extremely large volumes, particularly scrap metal and mine wastes. Costs to control and dispose of these wastes can be considerable. The current debate over the validity of LNT at low doses and low dose rates is particularly germane to this discussion. Most standards setting organizations and regulatory agencies base their recommendations on the LNT. The US Environmental Protection Agency has released a draft Federal Guidance Report that recommends calculating health risks from low-level exposure to radionuclides based on the LNT. However, some scientific and professional organizations are openly questioning the validity of LNT and its basis for regulations, practices, and costs to society in general. It is not clear at this time how a non-linear regulatory scheme would be implemented

  18. Regulatory Initiatives for Control and Release of Technologically Enhanced Naturally-Occurring Radioactive Materials

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, P.V.

    1999-03-02

    Current drafts of proposed standards and suggested State regulations for control and release of technologically-enhanced naturally-occurring radioactive material (TENORM), and standards for release of volumetrically-contaminated material in the US are reviewed. These are compared to the recommendations of the International Atomic Energy Association (IAEA) Safety Series and the European Commission (EC) proposals. Past regulatory efforts with respect to TENORM in the US dealt primarily with oil-field related wastes. Currently, nine states (AK, GA, LA, MS, NM, OH, OR SC, TX) have specific regulations pertaining to TENORM, mostly based on uranium mill tailings cleanup criteria. The new US proposals are dose- or risk-based, as are the IAEA and EC recommendations, and are grounded in the linear no threshold hypothesis (LNT). TENORM wastes involve extremely large volumes, particularly scrap metal and mine wastes. Costs to control and dispose of these wastes can be considerable. The current debate over the validity of LNT at low doses and low dose rates is particularly germane to this discussion. Most standards setting organizations and regulatory agencies base their recommendations on the LNT. The US Environmental Protection Agency has released a draft Federal Guidance Report that recommends calculating health risks from low-level exposure to radionuclides based on the LNT. However, some scientific and professional organizations are openly questioning the validity of LNT and its basis for regulations, practices, and costs to society in general. It is not clear at this time how a non-linear regulatory scheme would be implemented.

  19. Uncertainties in geologic disposal of high-level wastes - groundwater transport of radionuclides and radiological consequences

    International Nuclear Information System (INIS)

    Kocher, D.C.; Sjoreen, A.L.; Bard, C.S.

    1983-01-01

    The analysis for radionuclide transport in groundwater considers models and methods for characterizing (1) the present geologic environment and its future evolution due to natural geologic processes and to repository development and waste emplacement, (2) groundwater hydrology, (3) radionuclide geochemistry, and (4) the interactions among these phenomena. The discussion of groundwater transport focuses on the nature of the sources of uncertainty rather than on quantitative estimates of their magnitude, because of the lack of evidence that current models can provide realistic quantitative predictions of radionuclide transport in groundwater for expected repository environments. The analysis for the long-term health risk to man following releases of long-lived radionuclides to the biosphere is more quantitative and involves estimates of uncertainties in (1) radionuclide concentrations in man's exposure environment, (2) radionuclide intake by exposed individuals per unit concentration in the environment, (3) the dose per unit intake, (4) the number of exposed individuals, and (5) the health risk per unit dose. For the important long-lived radionuclides in high-level waste, uncertainties in most of the different components of a calculation of individual and collective dose per unit release appear to be no more than two or three orders of magnitude; these uncertainties are certainly much less than uncertainties in predicting groundwater transport of radionuclides between a repository and the biosphere. Several limitations in current models for predicting the health risk to man per unit release to the biosphere are discussed

  20. Impact of repository depth on residence times for leaking radionuclides in land-based surface water

    Science.gov (United States)

    Wörman, Anders; Marklund, Lars; Xu, Shulan; Dverstorp, Björn

    2007-03-01

    The multiple scales of landscape topography produce a wide distribution of groundwater circulation cells that control the hydro-geological environments surrounding geological repositories for nuclear waste. The largest circulation cells tend to discharge water into major river reaches, large freshwater systems or the nearby Baltic Sea. We investigated numerically the release of radionuclides from repositories placed in bedrock with depths between 100 to 2000 meters in a Swedish coastal area and found that leakage from the deeper positions emerges primarily in the major aquatic systems. In effect, radionuclides from the deeper repositories are more rapidly transported towards the Sea by the stream system compared to leakage from more shallow repositories. The release from the shallower repositories is significantly retained in the initial stage of the transport in the (superficial) landscape because the discharge occurs in or near low-order streams with high retention characteristics. This retention and residence time for radioactivity in the landscape control radiological doses to biota and can, thus, be expected to constitute an essential part of an associated risk evaluation.

  1. Radionuclide cardiography in medical practice

    International Nuclear Information System (INIS)

    Strangfeld, D.; Mohnike, W.; Schmidt, J.; Heine, H.; Correns, H.J.

    1986-01-01

    This publication is a compendium on all aspects of radionuclide diagnostics concerning cardiovascular system diseases. Starting with introductory remarks on the control of cardiovascular diseases the contribution of radionuclide cardiology to functional cardiovascular diagnostics as well as pathophysiological and pathobiochemical aspects of radiocardiography are outlined. Radiopharmaceuticals used in radiocardiography, physical and technical problems in application of radionuclides and their measuring techniques are discussed. In individual chapters radionuclide ventriculography, myocardial scintiscanning, circulatory diagnostics, radionuclide diagnostics of arterial hypertension, of thrombosis and in vitro diagnostics of thrombophilia are treated in the framework of clinical medicine

  2. 2006 LANL Radionuclide Air Emissions Report

    Energy Technology Data Exchange (ETDEWEB)

    David P. Fuehne

    2007-06-30

    This report describes the impacts from emissions of radionuclides at Los Alamos National Laboratory (LANL) for calendar year 2006. This report fulfills the requirements established by the Radionuclide National Emissions Standards for Hazardous Air Pollutants (Rad-NESHAP). This report is prepared by LANL's Rad-NESHAP compliance team, part of the Environmental Protection Division. The information in this report is required under the Clean Air Act and is being reported to the U.S. Environmental Protection Agency (EPA). The highest effective dose equivalent (EDE) to an off-site member of the public was calculated using procedures specified by the EPA and described in this report. LANL's EDE was 0.47 mrem for 2006. The annual limit established by the EPA is 10 mrem per year. During calendar year 2006, LANL continuously monitored radionuclide emissions at 28 release points, or stacks. The Laboratory estimates emissions from an additional 58 release points using radionuclide usage source terms. Also, LANL uses a network of air samplers around the Laboratory perimeter to monitor ambient airborne levels of radionuclides. To provide data for dispersion modeling and dose assessment, LANL maintains and operates meteorological monitoring systems. From these measurement systems, a comprehensive evaluation is conducted to calculate the EDE for the Laboratory. The EDE is evaluated as any member of the public at any off-site location where there is a residence, school, business, or office. In 2006, this location was the Los Alamos Airport Terminal. The majority of this dose is due to ambient air sampling of plutonium emitted from 2006 clean-up activities at an environmental restoration site (73-002-99; ash pile). Doses reported to the EPA for the past 10 years are shown in Table E1.

  3. Preliminary assessment of the controlled release of radionuclides from waste packages containing borosilicate waste glass

    International Nuclear Information System (INIS)

    Strachan, D.M.; McGrail, B.P.; Apted, M.J.; Engle, D.W.; Eslinger, P.W.

    1990-06-01

    The purpose of this report is to provide a preliminary assessment of the release-rate for an engineered barriers subsystem (EBS) containing waste packages of defense high-level waste borosilicate glass at geochemical and hydrological conditions similar to the those at Yucca Mountain. The relationship between the proposed Waste Acceptance Preliminary Specifications (WAPS) test of glass- dissolution rate and compliance with the NRC's release-rate criterion is also evaluated. Calculations are reported for three hierarchical levels: EBS analysis, waste-package analysis, and waste-glass analysis. The following conclusions identify those factors that most acutely affect the magnitude of, or uncertainty in, release-rate performance

  4. Realistic assessment of the radiological impact due to radionuclide releases to the terrestrial environment

    International Nuclear Information System (INIS)

    Proehl, G.

    2007-01-01

    Radioecological models are inherently associated with uncertainties, since ecological parameters are subject to a more or less pronounced variability; furthermore, the knowledge of the exposure conditions is - even in the best case - incomplete. To keep models simple and widely applicable and to avoid at the same time underestimations, parameters are selected with a conservative bias. However, conservative results are not appropriate for decision making and optimisation. To discuss the prevention of overly conservative models, in this paper, some selected processes are analysed that are involved in the transfer of radionuclides in the environment as e.g. interception of radionuclides deposited during precipitation by vegetation, systemic transport of radionuclides, migration of radionuclides in soil and speciation in soil. These processes are characterized, and it is discussed which factors should be integrated in modelling to achieve more realistic results. (author)

  5. Evaluation of radionuclide migration in the homogeneous system of a geological repository

    International Nuclear Information System (INIS)

    Prvakova, S.; Duran, J.; Necas, V.

    2005-01-01

    The aim of this paper is to study radionuclide migration and release from a deep underground repository situated in a clay formation. An insight into the processes influencing the radionuclide transport in the near field and far field will be presented. For the calculation, a set of radionuclides has been chosen, considering the half-life, decay chains, capacity of the sorption, solubility limits and diffusion coefficients. The migration of radionuclides is dependent on transport properties of the particular nuclide. Due to the low hydraulic conductivity of the backfill material and clay geological formation, the transport in the repository occurs mainly by diffusion. The migration rate will be influenced by the water chemistry, solubility, retardation and diffusive properties of the nuclides, and the water flow rate in the clay. The release rates of radionuclides from the geosphere to the biosphere will be converted into the indicative dose rates using dose conversion factors for ingestion. The impact of the critical group is considered via consumption of meat, root vegetables and drinking water from wells. (author)

  6. An analytical model for radioactive pollutant release simulation in the atmospheric boundary layer

    International Nuclear Information System (INIS)

    Weymar, Guilherme J.; Vilhena, Marco T.; Bodmann, Bardo E.J.; Buske, Daniela; Quadros, Regis

    2013-01-01

    Simulations of emission of radioactive substances in the atmosphere from the Brazilian nuclear power plant Angra 1 are a necessary tool for control and elaboration of emergency plans as a preventive action for possible accidents. In the present work we present an analytical solution for radioactive pollutant dispersion in the atmosphere, solving the time-dependent three-dimensional advection-diffusion equation. The experiment here used as a reference in the simulations consisted of the controlled releases of radioactive tritiated water vapor from the meteorological tower close to the power plant at Itaorna Beach. The wind profile was determined using experimental meteorological data and the micrometeorological parameters were calculated from empirical equations obtained in the literature. We report on a novel analytical formulation for the concentration of products of a radioactive chain released in the atmospheric boundary layer and solve the set of coupled equations for each chain radionuclide by the GILTT solution, assuming the decay of all progenitors radionuclide for each equation as source term. Further we report on numerical simulations, as an explicit but fictitious example and consider three radionuclides in the radioactive chain of Uranium 235. (author)

  7. An analytical model for radioactive pollutant release simulation in the atmospheric boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Weymar, Guilherme J.; Vilhena, Marco T.; Bodmann, Bardo E.J., E-mail: guicefetrs@gmail.com, E-mail: mtmbvilhena@gmail.com, E-mail: bejbodmann@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Buske, Daniela; Quadros, Regis, E-mail: danielabuske@gmail.com, E-mail: quadros99@gmail.com [Universidade Federal de Pelotas (UFPel), Capao do Leao, RS (Brazil). Programa de Pos-Graduacao em Modelagem Matematica

    2013-07-01

    Simulations of emission of radioactive substances in the atmosphere from the Brazilian nuclear power plant Angra 1 are a necessary tool for control and elaboration of emergency plans as a preventive action for possible accidents. In the present work we present an analytical solution for radioactive pollutant dispersion in the atmosphere, solving the time-dependent three-dimensional advection-diffusion equation. The experiment here used as a reference in the simulations consisted of the controlled releases of radioactive tritiated water vapor from the meteorological tower close to the power plant at Itaorna Beach. The wind profile was determined using experimental meteorological data and the micrometeorological parameters were calculated from empirical equations obtained in the literature. We report on a novel analytical formulation for the concentration of products of a radioactive chain released in the atmospheric boundary layer and solve the set of coupled equations for each chain radionuclide by the GILTT solution, assuming the decay of all progenitors radionuclide for each equation as source term. Further we report on numerical simulations, as an explicit but fictitious example and consider three radionuclides in the radioactive chain of Uranium 235. (author)

  8. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    S.O. Bader

    1999-10-18

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  9. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    International Nuclear Information System (INIS)

    S.O. Bader

    1999-01-01

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  10. Phase chemistry and radionuclide retention from simulated tank sludges

    International Nuclear Information System (INIS)

    KRUMHANSL, JAMES L.; LIU, J.; ARTHUR, SARA E.; HUTCHERSON, SHEILA K.; QIAN, MORRIS; ANDERSON, HOWARD L.

    2000-01-01

    Decommissioning high level nuclear waste tanks will leave small amounts of residual sludge clinging to the walls and floor of the structures. The permissible amount of material left in the tanks depends on the radionuclide release characteristics of the sludge. At present, no systematic process exists for assessing how much of the remaining inventory will migrate, and which radioisotopes will remain relatively fixed. Working with actual sludges is both dangerous and prohibitively expensive. Consequently, methods were developed for preparing sludge simulants and doping them with nonradioactive surrogates for several radionuclides and RCRA metals of concern in actual sludges. The phase chemistry of these mixes was found to be a reasonable match for the main phases in actual sludges. Preliminary surrogate release characteristics for these sludges were assessed by lowering the ionic strength and pH of the sludges in the manner that would occur if normal groundwater gained access to a decommissioned tank. Most of the Se, Cs and Tc in the sludges will be released into the first pulse of groundwater passing through the sludge. A significant fraction of the other surrogates will be retained indefinitely by the sludges. This prolonged sequestration results from a combination coprecipitated and sorbed into or onto relatively insoluble phases such as apatite, hydrous oxides of Fe, Al, Bi and rare earth oxides and phosphates. The coprecipitated fraction cannot be released until the host phase dissolves or recrystallizes. The sorbed fraction can be released by ion exchange processes as the pore fluid chemistry changes. However, these releases can be predicted based on a knowledge of the fluid composition and the surface chemistry of the solids. In this regard, the behavior of the hydrous iron oxide component of most sludges will probably play a dominant role for many cationic radionuclides while the hydrous aluminum oxides may be more important in governing anion releases

  11. A review of the role of colloids in the release and transport of radionuclides in the near and far field. Pt. 3

    International Nuclear Information System (INIS)

    Tipping, E.; Higgo, J.J.W.

    1992-01-01

    The role of colloids in the release and transport of radionuclides in the near and far field is discussed and DOE and Nirex funded work is compared with relevant studies by other workers. Gaps in the DOE and Nirex programmes are identified and suggestions for further research are made. This is Part 3 of a three-part review. Part 1 reviews fundamental theory and DOE and Nirex funded work and Part 2 is a comprehensive bibliography (with abstracts). (Author)

  12. Radionuclide generators

    International Nuclear Information System (INIS)

    Lambrecht, R.M.

    1983-01-01

    The status of radionuclide generators for chemical research and applications related to the life sciences and biomedical research are reviewed. Emphasis is placed upon convenient, efficient and rapid separation of short-lived daughter radionuclides in a chemical form suitable for use without further chemical manipulation. The focus is on the production of the parent, the radiochemistry associated with processing the parent and daughter, the selection and the characteristic separation methods, and yields. Quality control considerations are briefly noted. The scope of this review includes selected references to applications of radionuclide generators in radiopharmaceutical chemistry, and the life sciences, particularly in diagnostic and therapeutic medicine. The 99 Mo-sup(99m)Tc generator was excluded. 202 references are cited. (orig.)

  13. Radionuclide co-precipitation

    International Nuclear Information System (INIS)

    Bruno, J.; Sandino, A.

    1987-12-01

    The thermodynamic and kinetic behaviour of the minor components of the spent fuel matrix has been theoretically and experimentally investigated. Two different situations have been studied: Part I, the near field scenario, where the release and migration of the minor components is dependent on the solubility behaviour of UO 2 (s); Part II, the far field, where the solubility and transport of the radionuclides is related to the major geochemical processes occurring. (orig.)

  14. Assessment of the important radionuclides in nuclear waste

    International Nuclear Information System (INIS)

    Kerrisk, J.F.

    1985-10-01

    The relative importance of the various radionuclides contained in nuclear waste has been assessed by consideration of (1) the quantity of each radionuclide present, (2) the Environmental Protection Agency's release limits for radionuclides, (3) how retardation processes such as solubility and sorption affect radionuclie transport, and (4) the physical and chemical forms of radionuclides in the waste. Three types of waste were reviewed: spent fuel, high-level waste, and defense high-level waste. Conditions specific to the Nevada Nuclear Waste Storage Investigations project potential site at Yucca Mountain were used to describe radionuclide transport. The actinides Am, Pu, Np, and U were identified as the waste elements for which solubility and sorption data were most urgently needed. Other important waste elements were identified as Sr, Cs, C, Ni, Zr, Tc, Th, Ra, and Sn. Under some conditions, radionuclides of three elements (C, Tc, and I) may have high solubility and negligible sorption. The potential for transport of some waste elements (C and I) in the gas phase must also be evaluated for the Yucca Mountain Site. 12 refs., 17 tabs

  15. Process and research method of radionuclide migration in high level radioactive waste geological disposal system

    International Nuclear Information System (INIS)

    Chen Rui; Zhang Zhanshi

    2014-01-01

    Radionuclides released from waste can migrate from the repository to the rock and soil outside. On the other hand, nuclides also are retarded by the backfill material. Radionuclide migration is the main geochemical process of the waste disposal. This paper introduces various methods for radionuclide migration research, and give a brief analysis of the geochemical process of radionuclide migration. Finally, two of the most important processes of the radionuclide migration have been instanced. (authors)

  16. Selection of critical group in relation to the release of radionuclides from nuclear spent fuel reprocessing plant

    International Nuclear Information System (INIS)

    Ohmomo, Y.

    1980-01-01

    In respect of internal radiation due to the coastal release of radionuclides, survey on marine food consumption is most useful for the selection of critical group. Species of marine organisms they usually eat is fully over 100 in the coastal area of Ibaraki prefecture where the fuel reprocessing plant is located. Though it gives only a spot datum, one day's consumption survey a season is of convenience to obtain cooperation from housewives and is of use to pick up critical organisms and those who eat much of them. However, long-term survey is required to estimate ordinary intake of the critical foods or those who are supposed critical people. One day's consumption survey makes it easy to perform the subsequent long-term one

  17. Stimuli responsive nanomaterials for controlled release applications

    KAUST Repository

    Li, Song

    2012-01-01

    The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. Coupled with excellent biocompatibility profiles, various nanomaterials have showed great promise for biomedical applications. Stimuli-responsive nanomaterials guarantee the controlled release of cargo to a given location, at a specific time, and with an accurate amount. In this review, we have combined the major stimuli that are currently used to achieve the ultimate goal of controlled and targeted release by "smart" nanomaterials. The most heavily explored strategies include (1) pH, (2) enzymes, (3) redox, (4) magnetic, and (5) light-triggered release.

  18. User Guide ECOREA-RICE (version 1.0). Program for assessing the transfer of radionuclides released accidentally onto flooded rice-fields

    International Nuclear Information System (INIS)

    Keum, Dong Kwon; Lee, Han Soo; Choi, Hei Hu; Kang, Hee Seok; Lee, Chang Woo

    2004-05-01

    The computer code ECOREA-RICE is a dynamic compartment model that is specially designed for estimating the transfer of radionuclides deposited onto flooded rice-fields after an accidental release. The model consists of six independent compartments including rice-body, grain, surface water, root-zone soil, fixed soil and deep soil, and takes into account the transfer processes including radioactive decay, percolation, leaching, shoot-base absorption, root-uptake, weathering, translocation, fixation in soil by adsorption and desorption, and soil-mixing by plowing. The rate of the change of radioactivity in compartments is expressed by a set of the first order ordinary differential equations, which are solved by the fourth order Runge-Kutta algorithm. Input to the program includes the deposition date, transplanting date, ear emergence date, harvest date, soil data, the biomass data of rice-plant, and rate constants associated with transfer processes. Output includes the list of input data, the activity of radionuclides in compartment, the rate constant, and the transfer factor of rice-body and grain with time

  19. Radionuclide migration in soil within the estrangement zone of ChNPP

    International Nuclear Information System (INIS)

    Mikhalkin, G.S.; Arkhipov, A.N.; Arkhipov, N.P.; Sukhoruchkin, A.K.

    1992-01-01

    The problems of the radionuclide migration and redistribution in soil within the estrangement zone of ChNPP have been discussed. It has been demonstrated that the surface radioactive contamination of soil that has been represented principally by the particles of the waste nuclear fuel eventually migrates into soil depth. In this case the radionuclides remain principally the fuel matrix components, the fuel matrix decomposing gradually and releasing the radionuclides. The mechanisms of the radionuclide migration can be described with the quasi-diffusion migration model in most cases. On the 5th year since the accident the major portion of the radionuclides (95-99%) is still kept within 0-5 cm layer of soil. 3 figs.; 7 tabs

  20. Instant-release fractions for the assessment of used nuclear fuel disposal

    International Nuclear Information System (INIS)

    Garisto, N.C.; Vance, E.R.; Stroes-Gascoyne, S.; Johnson, L.H.

    1989-02-01

    Quantitative estimates of instant-release fractions for the potential release of radionuclides from used CANDU fuel in an underground disposal vault have been made in terms of probability- density functions, taking variability and uncertainty into account. The radionuclides included in this study are 129 I, 135 Cs, 79 Se, 126 Sn, 99 Tc, 14 C, and 3 H. The probability-density functions are based on experimental data on the short term release of radionuclides upon contact with groundwater, and on a knowledge of the solid-state chemistry of used fuel. They provide source terms for the environmental and safety assessment of used nuclear fuel disposal

  1. Effect of cooking on radionuclide concentrations in waterfowl tissues

    International Nuclear Information System (INIS)

    Halford, D.K.

    1983-01-01

    Twenty-four commercially raised mallar ducks (Anas platyrhyncos) were released at the Test Reactor Area radioactive leaching ponds, and subsequently collected 56 to 188 days later. Liver, gizzard, and carcass were analyzed for radionuclide concentrations before and after cooking. Significant decreases (P 137 Cs, 134 Cs, 60 Co, 140 La and /sup 110m/Ag concentrations in carcass and liver samples occurred after cooking. Radionuclide concentrations in gizzard showed no significant change in radionuclide concentrations after cooking. Cesium-134 and 137 Cs concentrations decreased by 27% in carcass after cooking and reduced the dose commitment to man by that amount

  2. Summary of estimated doses and risks resulting from routine radionuclide releases from fast breeder reactor fuel cycle facilities

    International Nuclear Information System (INIS)

    Miller, C.W.; Meyer, H.R.

    1985-01-01

    A project is underway at Oak Ridge National Laboratory to assess the human health and environment effects associated with operation of Liquid Metal Fast Breeder Reactor fuel cycle. In this first phase of the work, emphasis was focused on routine radionuclide releases from reactor and reprocessing facilities. For this study, sites for fifty 1-GW(e) capacity reactors and three reprocessing plants were selected to develop scenarios representative of US power requirements. For both the reactor and reprocessing facility siting schemes selected, relatively small impacts were calculated for locality-specific populations residing within 100 km. Also, the results of these analyses are being used in the identification of research priorities. 13 refs., 2 figs., 3 tabs

  3. Performance and quality control of radionuclide calibrators in nuclear medicine

    International Nuclear Information System (INIS)

    Woods, M.J.; Baker, M.

    2002-01-01

    Full text: The use of ionising radiations in nuclear medicine has traditionally divided itself into two specific areas. The diagnostic usage has generally been dominated by the injection or ingestion of radionuclides. The therapeutic applications, on the other hand, have usually been accomplished by the application of ionising radiation, both from machines and radionuclide sources, whereby the radiation source is external to the patient. Over recent years, this divide has become increasingly blurred and the science between diagnosis and therapy has become significantly closer. This is particularly the situation in respect of the instruments used to determine the activity or dose delivered by the radiation source. In the ideal therapeutic situation, the radiation dose would be delivered solely to the malignant tissue. With external radiation therapy, this can never be achieved completely but this ideal can be approached more closely with targeted radiotherapy wherein radionuclides are introduced directly into the malignancy either as a solid, physical source or as a solution that, by its chemistry, concentrates into the area of interest. In order to achieve the optimum efficacy of treatment, there is an associated requirement to determine accurately the activity or dose rate of the radioactive source being used. It is here that the technology used in the diagnostic field can also be used to advantage for therapeutic applications. For diagnosis, the instrument of choice is the radionuclide calibrator and this equipment is increasingly finding parallel usage for the characterisation of therapeutic sources. Despite their appearances however, radionuclide calibrators are not 'black boxes' and need to be used with care, subjected to a robust level of quality control and operated by personnel who have a fundamental understanding of their operational characteristics. A measure of the level of performance of operational radionuclide calibrators and the competence of their

  4. Selection of dominant radionuclides for Phase 1 of the Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Napier, B.A.

    1991-07-01

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that individuals could have received as a result of emissions from nuclear operations at Hanford since their inception in 1944. A vital step in the estimation of radiation doses is the determination of the source term,'' that is, the quantities of radionuclides that were released to the environment from the various Hanford operations. Hanford operations have at various times involved hundreds of different radionuclides, some in relatively large quantities. Those radionuclides present in the largest quantities, although significant from an operational handling point of view, may not necessarily have been those of greatest concern for offsite radiation dose. This report documents the selection of the dominant radionuclides (those that may have resulted in the largest portion of the received doses) in the source term for Phase 1 of the HEDR Project, that is, for atmospheric releases from 1944 through 1947 and for surface water releases from 1964 through 1966. 15 refs., 3 figs., 10 tabs.

  5. Sources of anthropogenic radionuclides in the environment: a review

    International Nuclear Information System (INIS)

    Hu Qinhong; Weng Jianqing; Wang Jinsheng

    2010-01-01

    Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview on sources of anthropogenic radionuclides in the environment, as well as a brief discussion of salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current developments that have lead, or could potentially contribute, to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) uranium mining and milling; (5) commercial fuel reprocessing; (6) geological repository of high-level nuclear wastes that include radionuclides might be released in the future, and (7) nuclear accidents. Then, we briefly summarize the inventory of radionuclides 99 Tc and 129 I, as well as geochemical behavior for radionuclides 99 Tc, 129 I, and 237 Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment; biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

  6. Modelling of radionuclide transport along the underground access structures of deep geological repositories

    Energy Technology Data Exchange (ETDEWEB)

    Poller, A. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Smith, P. [SAM Switzerland GmbH, Zuerich (Switzerland); Mayer, G.; Hayek, M. [AF-Consult Switzerland AG, Baden (Switzerland)

    2014-08-15

    system are finally evaluated using biosphere dose conversion factors. The detailed modelling approaches used are to some extent rather simple and stylised. All simplifications clearly lead to an overestimate of releases. The results obtained for the HLW and for the L/ILW repository are generally similar. Quantitative differences arise from the size of the main facility, from the inventory and the properties of the emplaced waste, as well as from the concepts of how radionuclides are released from the different waste forms. The results show that radionuclide release along the access structures of a deep geological repository is extremely low. Radionuclide release occurs predominantly through the host rock. Globally increasing the hydraulic conductivities that are assumed for the tunnel system and the seals (including the excavation damage zone along these underground structures) increases the calculated flows along all access routes, but the increase is found to level off with increasing hydraulic conductivity of seals and excavation damage zones, as flow becomes ultimately controlled by the limited capacity of the host rock to supply water. The dose rate maxima due to releases via the access structures show the same asymptotic behaviour as the flow, and remain low in all cases. The calculated release rates along the access structures are very low for all variants considered and, in particular, far less than the release rates from the host rock. It is thus concluded that the type of main access route to the underground facilities of a deep geological repository with properties as assumed for the present study is not relevant to its post-closure safety. Finally, even for highly unfavourable parameter values for the hydraulic properties of the seals and the associated excavation damage zones, the calculated dose rates remain well below the regulatory protection criterion of 0.1 mSv per year, often by several orders of magnitude. This finding demonstrates the robustness of

  7. Environmental Management Department Quality Assurance Project Plan for Radionuclide Emission Measurements Project for compliance with National Emission Standards for Hazardous Air Pollutants (NESHAP)

    Energy Technology Data Exchange (ETDEWEB)

    Poole, D A

    1992-06-01

    This Quality Assurance Project Plan (QAPP) satisfies the quality assurance (QA) requirements in 40 CFR Part 61, Method 114, for ensuring that the radionuclide air emission measurements from the Y-12 Plant are representative; of a known precision and accuracy; and include administrative controls to ensure prompt response when emission measurements indicate an increase over normal radionuclide emissions. The QAPP ensures the quality of the Y-12 Plant radionuclide emission measurements data from the continuous samplers, breakthrough monitors, and minor radionuclide release points. The plan specifies the procedures for the management of the activities affecting the quality of the data for the Y-12 Plant Environmental Management Department (EMD) within the Health, Safety, Environment, and Accountability Division (HSEA).

  8. Environmental Management Department Quality Assurance Project Plan for Radionuclide Emission Measurements Project for compliance with National Emission Standards for Hazardous Air Pollutants (NESHAP)

    International Nuclear Information System (INIS)

    Poole, D.A.

    1992-06-01

    This Quality Assurance Project Plan (QAPP) satisfies the quality assurance (QA) requirements in 40 CFR Part 61, Method 114, for ensuring that the radionuclide air emission measurements from the Y-12 Plant are representative; of a known precision and accuracy; and include administrative controls to ensure prompt response when emission measurements indicate an increase over normal radionuclide emissions. The QAPP ensures the quality of the Y-12 Plant radionuclide emission measurements data from the continuous samplers, breakthrough monitors, and minor radionuclide release points. The plan specifies the procedures for the management of the activities affecting the quality of the data for the Y-12 Plant Environmental Management Department (EMD) within the Health, Safety, Environment, and Accountability Division (HSEA)

  9. The influence of season of the year on the predicted agricultural consequences of accidental releases of radionuclides to atmosphere

    International Nuclear Information System (INIS)

    Simmonds, J.R.

    1985-02-01

    In Europe, because of the seasonal nature of agricultural practices, the consequences for agriculture of an accidental release of radioactive materials to atmosphere are likely to vary depending upon the time of year when the release occurs. The quantification of this variation is complicated by the need to take into account the introduction of countermeasures to restrict the radiation exposure from ingestion of contaminated foods, and by the presence in accidental releases of radionuclides which persist over several seasons. In this study, the effect on agricultural consequences of accidental releases occurring at different times of the year is examined. The consequences are expressed in terms of the amount of produce affected by restrictions on food supplies and the collective radiation dose from ingestion of food. The investigation has been carried out for three hypothetical releases representing a range of releases postulated for pressurised water reactors (PWRs). The effect of season of the year was determined for accidental releases occurring both in a single, defined set of meteorological conditions and for a range of possible meteorological conditions. For the main part of the study, consideration was limited to agricultural production in the UK only, but the effect of extending the analysis beyond the UK boundary was also considered. The results of the study show that considerable variation can occur in agricultural consequences following an accidental release at different times of the year. For the larger releases considered, this variation is reduced due to the effect of the introduction of countermeasures, particularly when consideration is limited to the UK only. Seasonal variation tends to be greater for the results of a deterministic analysis, which uses a single set of constant meteorological conditions, than for the results of a full probabilistic assessment. From the results presented here it is also seen that for many applications of

  10. Radionuclide transport in a single fissure

    International Nuclear Information System (INIS)

    Eriksen, T.E.

    1988-12-01

    The study of radionuclide migration through rock is currently of great interest due to its relevance to the possible escape paths into the biosphere of radionuclides released from high level radioactive wastes burried in deep geological repositories. While water will provide the vehicle for transportation, interaction with geological material may greatly influence the radionuclide movement relative that of water. A flow system for laboratory studies of radionuclide transport in natural fissures in granitic rock under reducing conditions is described. The system based on the use of synthetic ground water equilibrated with granitic rock in a well sealed system, allow experiments to be carried out at -240 mV reduction potential. In flow experiments with technetium the retardation was found to be dependent on the method used for reducing TcO 4 - . The preparation of the tracer solutions is crucial, as some of the redox-reactions may be very slow. The dynamics of the Tc(VII) reduction and also speciation need to be carried out in separate experiments. (4 illustrations, 5 tables)

  11. RIVER-RAD, Radionuclide Transport in Surface Waters

    International Nuclear Information System (INIS)

    1996-01-01

    1 - Description of program or function: RIVER-RAD assesses the potential fate of radionuclides released to rivers. The model is simplified in nature and is intended to provide guidance in determining the potential importance of the surface water pathway, relevant transport mechanisms, and key radionuclides in estimating radiological dose to man. 2 - Method of solution: A compartmental linear transfer model is used in RIVER-RAD. The river system model in the code is divided into reaches (compartments) of equal size, each with a sediment compartment below it. The movement of radionuclides is represented by a series of transfers between the reaches, and between the water and sediment compartments of each reach. Within each reach (for both the water and sediment compartments), the radionuclides are assumed to be uniformly mixed. Upward volatilization is allowed from the water compartment, and the transfer of radionuclides between the reaches is determined by the flow rate of the river. Settling and resuspension velocities determine the transfer of absorbed radionuclides between the water and sediment compartments. Radioactive decay and decay-product buildup are incorporated into all transport calculations for all radionuclide chains specified by the user. Each nuclide may have unique input and removal rates. Volatilization and radiological decay are considered as linear rate constants in the model. 3 - Restrictions on the complexity of the problem: None noted

  12. Sellafield waste radionuclides in Irish sea intertidal and salt marsh sediments.

    Science.gov (United States)

    Mackenzie, A B; Scott, R D

    1993-09-01

    Low level liquid radioactive waste discharges from the Sellafield nuclear fuel reprocessing plant in north west England had generated environmental inventories of about 3 × 10(16) Bq of(137)Cs, 6.8 × 10(14) Bq of(239,240)Pu and 8.9 × 10(14) Bq of(241)Am by 1990. Most of the(239,240)Pu and(241)Am and about 10% of the(137)Cs has been retained in a deposit of fine marine sediment close to the discharge point. The quantities of radionuclides discharged annually from Sellafield decreased by two orders of magnitude from the mid-1970s to 1990 but estimated critical group internal and external exposure decreased by less than one order of magnitude over this period. This indicates that during the period of reduced discharges, radionuclides already in the environment from previous releases continued to contribute to the critical group exposure and highlights the need to understand processes controlling the environmental distribution of the radionuclides.Redistribution of the contaminated marine sediment is potentially of major significance in this context, in particular if it results in transport of radionuclides to intertidal areas, where contact with the human population is relatively likely.A review is presented of published work relating to Sellafield waste radionuclides in Irish Sea sediments. Data on temporal and spatial trends in radionuclide concentrations and activity ratios are collated from a number of sources to show that the dominant mechanism of radionuclide supply to intertidal areas is by redistribution of the contaminated marine sediment. The implications of this mechanism of supply for trends in critical group radiation exposure are considered.

  13. Mechanisms controlling radionuclide mobility in forest soils

    International Nuclear Information System (INIS)

    Delvaux, B.; Kruyts, N.; Maes, E.; Agapkina, G.I.; Kliashtorin, A.; Bunzl, K.; Rafferty, B.

    1996-01-01

    Soil processes strongly influence the radionuclide mobility in soils. The mobility of radionuclides in forest soils is governed by several processes involving both abiotic and biotic factors. The sorption-desorption process chiefly governs the activity of radionuclides in the soil solution, hence thereby their mobility and biological availability. Radiocaesium exhibits a very low mobility in mineral soils. Both mobility and bioavailability however increase as the thickness of organic layers and their content in organic matter increases. Clay minerals of micaceous origin strongly act as slinks for radiocaesium in forest soils. The magnitude of cesium mineral fixation in topsoils is expected to be the highest in mineral soils of Eutric cambisol type, and, to a lesser extent, of type of Distric cambisol and Podzoluvisol. A low mobility of radiocaesium in the surface horizons of forest soils may also be partially explained by a biological mobilization: fungi absorb radiocaesium and transport it to upper layers, thereby contributing to constantly recycle the radioelement in the organic horizons. This mechanism is probably important in soils with thick organic layers (Podsol, Histosol, and, to a lesser extent, Distric cambisol and Podzoluvisol). Radionuclides can be associated with soluble organic anions in the soil solution of forest acid soils. Such associations are highly mobile: they are stable in conditions of poor biological activity (low temperatures, acid soil infertility, water excess, etc.). Their magnitude is expected to be the highest in thick acid organic layers (soils of type Podzol and Histosol)

  14. Radionuclide transport processes in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Whicker, F.W.

    1983-01-01

    Some major principles and the status of knowledge concerning the transport of radionuclides through terrestrial ecosystems are reviewed. Fundamental processes which control the flow of radionuclides between ecosystem components such as air, soil, plants, and animals are described, with emphasis on deposition, resuspension, plant uptake, ingestion, and assimilation. Properties of radionuclides, organisms, and ecosystems are examined in relation to their influence on the accumulation of radioactive materials by plants and animals. The effects of the physicochemical nature of the radionuclide; morphology, physiology, and behavior of the organism; and soil, nutrient, and trophic characteristics of the ecosystem are highlighted. Observations in natural ecosystems on radionuclides such as 137 Cs, 90 Sr, 131 I, 3 H, and 239 Pu are used to illustrate current concepts. An assessment of the degree to which the processes controlling radionuclide behavior are understood and of our ability to simulate and predict such behavior with computerized models is offered. Finally, brief comments are made on research needs

  15. Heat-pipe effect on the transport of gaseous radionuclides released from a nuclear waste container

    International Nuclear Information System (INIS)

    Zhou, W.; Chambre, P.L.; Pigford, T.H.; Lee, W.W.L.

    1990-11-01

    When an unsaturated porous medium is subjected to a temperature gradient and the temperature is sufficiently high, vadose water is heated and vaporizes. Vapor flows under its pressure gradient towards colder regions where it condenses. Vaporization and condensation produce a liquid saturation gradient, creating a capillary pressure gradient inside the porous medium. Condensate flows towards the hot end under the influence of a capillary pressure gradient. This is a heat pipe in an unsaturated porous medium. We study analytically the transport of gaseous species released from a spent-fuel waste package, as affected by a time-dependent heat pipe in an unsaturated rock. For parameter values typical of a potential repository in partially saturated fractured tuff at Yucca Mountain, we found that a heat pipe develops shortly after waste is buried, and the heat-pipe's spatial extent is time-dependent. Water vapor movements produced by the heat pipe can significantly affect the migration of gaseous radionuclides. 12 refs., 6 figs., 1 tab

  16. Clearance levels for radionuclides in solid materials. Application of exemption principles. Interim report for comment

    International Nuclear Information System (INIS)

    1996-01-01

    This report proposes levels of radionuclides in solid wastes below which regulatory control may be relinquished on the grounds that the associated radiation hazards are trivial. The radiological basis for the guidance is the international consensus on principles for the exemption of radiation sources and practices from regulatory control reached in 1988 and published in IAEA Safety Series No. 89. The levels are intended as international reference values. The levels may be seen as those below which release from regulatory control is 'automatic' without further consideration being needed. Release from regulatory control may, of course, be allowed under other conditions; regulatory authorities may decide, on the basis of a generic or site specific optimization subject to dose constraints, to select other, less restrictive, release levels. This optimization process includes consideration of factors other than those associated with radiation protection, for example, those concerned with the health, social, environmental and economic benefits and risks of implementing the practice. 44 refs, tabs

  17. Dual-controlled release system of drugs for bone regeneration.

    Science.gov (United States)

    Kim, Yang-Hee; Tabata, Yasuhiko

    2015-11-01

    Controlled release systems have been noted to allow drugs to enhance their ability for bone regeneration. To this end, various biomaterials have been used as the release carriers of drugs, such as low-molecular-weight drugs, growth factors, and others. The drugs are released from the release carriers in a controlled fashion to maintain their actions for a long time period. Most research has been focused on the controlled release of single drugs to demonstrate the therapeutic feasibility. Controlled release of two combined drugs, so-called dual release systems, are promising and important for tissue regeneration. This is because the tissue regeneration process of bone formation is generally achieved by multiple bioactive molecules, which are produced from cells by other molecules. If two types of bioactive molecules, (i.e., drugs), are supplied in an appropriate fashion, the regeneration process of living bodies will be efficiently promoted. This review focuses on the bone regeneration induced by dual-controlled release of drugs. In this paper, various dual-controlled release systems of drugs aiming at bone regeneration are overviewed explaining the type of drugs and their release materials. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. A model for radionuclide transport in the Cooling Water System

    International Nuclear Information System (INIS)

    Kahook, S.D.

    1992-08-01

    A radionuclide transport model developed to assess radiological levels in the K-reactor Cooling Water System (CWS) in the event of an inadvertent process water (PW) leakage to the cooling water (CW) in the heat exchangers (HX) is described. During and following a process water leak, the radionuclide transport model determines the time-dependent release rates of radionuclide from the cooling water system to the environment via evaporation to the atmosphere and blow-down to the Savannah River. The developed model allows for delay times associated with the transport of the cooling water radioactivity through cooling water system components. Additionally, this model simulates the time-dependent behavior of radionuclides levels in various CWS components. The developed model is incorporated into the K-reactor Cooling Tower Activity (KCTA) code. KCTA allows the accident (heat exchanger leak rate) and the cooling tower blow-down and evaporation rates to be described as time-dependent functions. Thus, the postulated leak and the consequence of the assumed leak can be modelled realistically. This model is the first of three models to be ultimately assembled to form a comprehensive Liquid Pathway Activity System (LPAS). LPAS will offer integrated formation, transport, deposition, and release estimates for radionuclides formed in a SRS facility. Process water and river water modules are forthcoming as input and downstream components, respectively, for KCTA

  19. How controlled release technology can aid gene delivery.

    Science.gov (United States)

    Jo, Jun-Ichiro; Tabata, Yasuhiko

    2015-01-01

    Many types of gene delivery systems have been developed to enhance the level of gene expression. Controlled release technology is a feasible gene delivery system which enables genes to extend the expression duration by maintaining and releasing them at the injection site in a controlled manner. This technology can reduce the adverse effects by the bolus dose administration and avoid the repeated administration. Biodegradable biomaterials are useful as materials for the controlled release-based gene delivery technology and various biodegradable biomaterials have been developed. Controlled release-based gene delivery plays a critical role in a conventional gene therapy and genetic engineering. In the gene therapy, the therapeutic gene is released from biodegradable biomaterial matrices around the tissue to be treated. On the other hand, the intracellular controlled release of gene from the sub-micro-sized matrices is required for genetic engineering. Genetic engineering is feasible for cell transplantation as well as research of stem cells biology and medicine. DNA hydrogel containing a sequence of therapeutic gene and the exosome including the individual specific nucleic acids may become candidates for controlled release carriers. Technologies to deliver genes to cell aggregates will play an important role in the promotion of regenerative research and therapy.

  20. Position Paper on Practicable Performance Criteria for the Removal Efficiency of Volatile Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    R. T. Jubin; N. Soelberg; D. M. Strachan

    2012-03-01

    As a result of fuel reprocessing, volatile radionuclides may be released from the facility stack if no processes are put in place to remove them. The radionuclides that are of concern in this document are 3H, 14C, 85Kr, and 129I. The question we attempted to answer is how efficient must this removal process be for each of these radionuclides? To answer this question, we examined the three regulations that may impact the degree to which these radionuclides must be reduced before process gases can be released from the facility. These regulations are 40 CFR 61 (EPA 2010a), 40 CFR 190(EPA 2010b), and 10 CFR 20 (NRC 2012). These regulations apply to the total radionuclide release and to a particular organ - the thyroid. Because these doses can be divided amongst all the radionuclides in different ways and even within the four radionuclides in question, we provided several cases. We first looked at the inventories for these radionuclides for three fuel types (PWR UOX, PWR MOX, and AHTGR), several burn-up values, and time out of reactor extending to 200 y. We calculated doses to the maximum exposed individual (MEI) with the EPA code CAP-88 (Rosnick 1992). Finally, we looked at two dose cases. Allocating all of the allowable dose to be used by the volatile radionuclides is one case, but, perhaps, unrealistic. In lieu of this, we arbitrarily selected a value of 10% of the allowable dose to be assigned to the volatile radionuclides. We calculated the required decontamination factors (DFs) for both of these cases, including the case for the thyroid dose for which 14C and 129I were the main contributors. With respect to 129I doses, we found that the highest dose was calculated with iodine as a fine particulate. The dose scaled as the fraction of the total 129I that was particulate. Therefore, we assumed for all of our calculations that 100% of the 129I was particulate and allow the user of the results given here to scale our calculated doses to their needs.

  1. Commercial SNF Accident Release Fractions

    Energy Technology Data Exchange (ETDEWEB)

    J. Schulz

    2004-11-05

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the

  2. Commercial SNF Accident Release Fractions

    International Nuclear Information System (INIS)

    Schulz, J.

    2004-01-01

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M andO 1999). In contrast to bare unconfined fuel assemblies, the

  3. Radionuclide accumulations in Clinch River fish

    International Nuclear Information System (INIS)

    Oakes, T.W.; Easterly, C.E.; Shank, K.E.

    1976-01-01

    Fish samples were collected from several locations above Melton Hill Dam, which is upstream from the liquid effluent release point of the Oak Ridge National Laboratory. The sampling locations were chosen to determine the accumulation of natural and man-made radionuclides in fish from areas in the Clinch River not influenced by the Laboratory's liquid effluents. Bass, carp, crappie, shad, bluegill, and other sunfish were collected; ten fish per species were composited to form a single sample for each location. The gamma-emitting radionuclide concentrations were determined by gamma-ray spectroscopy. Estimates of radiological dose to man subsequent to ingestion of these fish are made

  4. Estimating radionuclide air concentrations near buildings: a screening approach

    International Nuclear Information System (INIS)

    Miller, C.W.; Yildiran, M.

    1984-01-01

    For some facilities that routinely release small amounts of radionuclides to the atmosphere, such as hospitals, research laboratories, contaminated clothing laundries, and others, it is necessary to estimate the dose to persons very near the buildings from which the releases occur. Such facilities need simple screening procedures which provide reasonable assurance that as long as the calculated dose is less than some fraction of a relevant dose limit no individual will receive a dose in excess of that limit. Screening procedures have been proposed for persons living within hundreds of meters to a few kilometers from a source of radioactive effluent. This paper examines a screening technique for estimating long-term average radionuclide air concentrations within approximately 100 m of a building from which the release occurs. The technique is based on a modified gaussion plume model (HB model) which considers the influence of the tallest building within 100 m and is independant of atmospheric stability and downwind distance. 4 references, 2 tables

  5. Radionuclide dispersion and hydrodynamics of Ilha Grande Bay (Angra dos Reis, RJ) simulated from hypothetical accidental releases of liquid wastes

    International Nuclear Information System (INIS)

    Simoes Filho, Fernando Lamego; Lapa, Celso Marcelo Franklin; Aguiar, Andre Silva; Soares, Abner Duarte

    2011-01-01

    This study has the aim to assess the impact of accidental release of radionuclides postulate from a nuclear power reactor through environmental modeling of aquatic resources. In order to do that it was used computational models of hydrodynamic circulation and transport for the simulation of tritium dispersion caused by an accidental release in Ilha Grande Bay from the site of the future third plant in two circulation scenarios. The main difference between the scenarios is based on the enhancement of dilution of the highest concentrations in the last one. This dilution enhancement resulting in decreasing concentrations was observed only during the first two weeks, when they ranged from 1 x 10 9 to 5 x 10 5 Bq/m³ close to the Itaorna beach spreading just to Sandri Island. After 180 days, the plume could not be detected anymore in the bay, because their activities would be lower than the minimum detectable value (< 11 kBq/m³). (author)

  6. Migration of radionuclide chains through an adsorbing medium

    International Nuclear Information System (INIS)

    Lester, D.H.; Jansen, G.; Burkholder, H.C.

    1974-12-01

    The migration of actinides and other radionuclides from an underground geologic nuclear waste disposal site through a soil column to a surface water body was investigated for impulse and band releases. Numerical calculation of the analytical solutions revealed that differences in adsorption characteristics between chain members, axial dispersion, and radioactive decay all act to reduce radionuclide discharge rates at the exit of the soil column. The results of the study may have important implications in the underground storage and disposal of nuclear waste. (U.S.)

  7. Effects of processing on radionuclide content of food -implications for radiological assessments

    International Nuclear Information System (INIS)

    Green, N.; Wilkins, B.T.

    1996-01-01

    Published information on the effects of processing on the radionuclide content of food has been reviewed. Data are scarce: the majority of the available information concerns 137 Cs, 90 Sr and 131 I, with some dealing with 35 S, 210 Pb and 210 Po. For broad assessments of doses to critical groups from controlled releases, processes that can be carried out on a domestic or local scale are of greatest relevance. In this case, food can be prepared in various ways and cooking liquors can also be consumed, either directly or in the form of sauces. Consequently, when making estimates of intakes of activity, it would be reasonable to assume that, that for the majority of food items and most radionuclides, effectively no loss occurs as a result of processing, provided that the activity concentrations in the foodstuff relate to the edible portion. More information on the behaviour of potentially volatile radionuclides during cooking would however be useful. Recommendations are made about the presentation of data on food processing. (Author)

  8. Study of the hydrodynamic circulation and transport of radionuclides in the Ilha Grande Bay -RJ

    International Nuclear Information System (INIS)

    Franklin, Mariza Ramalho

    2001-01-01

    The Almirante Alvaro Alberto Nuclear Center (CNAAA), located at the city of Rio de Janeiro and the liquid effluents are released into the Ilha Grande Bay (BIG). The objective of this work was to simulate mathematically the dispersion of 3 H and 137 Cs present in the liquid effluents that are routinely released into the environment, and in this way contribute to the improvement of the radiological impact assessment associated to these releases. The hydrodynamic circulation pattern of the bay and the transport of radionuclides were simulated by means of numerical modeling techniques by the computational system SisBAHIA (Sistema Base Hidrodinâmica e Ambiental). The results indicate that the local circulation pattern is mainly driven by the propagation of the tidal wave, and is characterized by low current velocities of about 0.1 m.s -1 . The wind stress (normal or extreme ones ) over the free surface does not alter the local circulation pattern significantly. The effluents are released in a rate of about 120 m 3 .s. -1 . As a result, the local hydrodynamics is markedly altered by means of the formation of a huge vortices close to the release area. According to the annual amount of the released radionuclides predicted in the Nuclear Licensing Document, and considering a continuous release it could be predicted that the radionuclide plume would present a low mobility, with most of the activity concentration amount being restricted close to the source. The activity concentration distribution reach the transportation steady state by the end of the 51 st day of simulation. A conservative behavior of both radionuclides in the water column was assumed in the performed simulation. (author)

  9. Effect of Concrete Waste Form Properties on Radionuclide Migration

    International Nuclear Information System (INIS)

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Skinner, De'Chauna J.; Cordova, Elsa A.; Wood, Marcus I.

    2009-01-01

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation) the mechanism of contaminant release, the significance of contaminant release pathways, how waste form performance is affected by the full range of environmental conditions within the disposal facility, the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility, the effect of waste form aging on chemical, physical, and radiological properties and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. Numerous sets of tests were initiated in fiscal years (FY) 2006-2009 to evaluate (1) diffusion of iodine (I) and technetium (Tc) from concrete into uncontaminated soil after 1 and 2 years, (2) I and rhenium (Re) diffusion from contaminated soil into fractured concrete, (3) I and Re (set 1) and Tc (set 2) diffusion from fractured concrete into uncontaminated soil, (4) evaluate the moisture distribution profile within the sediment half-cell, (5) the reactivity and speciation of uranium (VI) (U(VI)) compounds in concrete porewaters, (6) the rate of dissolution of concrete monoliths, and (7) the diffusion of simulated tank waste into concrete.

  10. Environmental dispersion of long-lived radionuclides in the geosphere and biosphere

    International Nuclear Information System (INIS)

    Myttenaere, C.; Avogadro, A.; Murray, C.N.

    1984-01-01

    Knowledge of the migration of radionuclides in the terrestrial environment is one of the key elements in assessment of the risk resulting from potential or actual releases from nuclear facilities. Among the various radionuclides arising from the nuclear fuel cycle, long-lived fission products and actinides are of particular concern for the different disposal options considered for radioactive wastes. Current knowledge of the processes that are responsible for their migration through different compartments of the environment (geosphere and biosphere) is reviewed. Migration in the geosphere is governed by a number of different mechanisms that have a wide range of reaction rates. Certain processes may be identified that control short-term behaviour and others long term. In assessing these processes, which relate to the interaction between solid and liquid phases, special attention is paid to the time-scale as well as the dynamic nature of the controlling processes. The current state of knowledge and the major research efforts under way concerning the predominant processes identified in different geological disposal options are reviewed. Various mechanisms control the behaviour of long-lived radionuclides and actinides in the soil and their migration in the biosphere. Regarding the biological uptake, particular attention is drawn to the 'ageing' phenomena and their consequences on radioactivity transfer in the different food chains. Similarities in the biogeochemical properties of natural and man-made elements that could further our understanding of the long-term behaviour of radionuclides are discussed. Consequently, all these considerations justify study of the biogeochemical aspects of the transfer of radioactivity in the environment. In the actual state of knowledge the uncertainties in the parameters used in the models may lead to difficulty in long-term dose estimation. Assessment of the dose received by man appears to be more strongly limited by the quality of

  11. 28 CFR 541.50 - Release from a control unit.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Release from a control unit. 541.50... INMATE DISCIPLINE AND SPECIAL HOUSING UNITS Control Unit Programs § 541.50 Release from a control unit. (a) Only the Executive Panel may release an inmate from a control unit. The following factors are...

  12. Toward a Mechanistic Source Term in Advanced Reactors: Characterization of Radionuclide Transport and Retention in a Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Brunett, Acacia J.; Bucknor, Matthew; Grabaskas, David

    2016-04-17

    A vital component of the U.S. reactor licensing process is an integrated safety analysis in which a source term representing the release of radionuclides during normal operation and accident sequences is analyzed. Historically, source term analyses have utilized bounding, deterministic assumptions regarding radionuclide release. However, advancements in technical capabilities and the knowledge state have enabled the development of more realistic and best-estimate retention and release models such that a mechanistic source term assessment can be expected to be a required component of future licensing of advanced reactors. Recently, as part of a Regulatory Technology Development Plan effort for sodium cooled fast reactors (SFRs), Argonne National Laboratory has investigated the current state of knowledge of potential source terms in an SFR via an extensive review of previous domestic experiments, accidents, and operation. As part of this work, the significant sources and transport processes of radionuclides in an SFR have been identified and characterized. This effort examines all stages of release and source term evolution, beginning with release from the fuel pin and ending with retention in containment. Radionuclide sources considered in this effort include releases originating both in-vessel (e.g. in-core fuel, primary sodium, cover gas cleanup system, etc.) and ex-vessel (e.g. spent fuel storage, handling, and movement). Releases resulting from a primary sodium fire are also considered as a potential source. For each release group, dominant transport phenomena are identified and qualitatively discussed. The key product of this effort was the development of concise, inclusive diagrams that illustrate the release and retention mechanisms at a high level, where unique schematics have been developed for in-vessel, ex-vessel and sodium fire releases. This review effort has also found that despite the substantial range of phenomena affecting radionuclide release, the

  13. Conditions and processes affecting radionuclide transport

    Science.gov (United States)

    Simmons, Ardyth M.; Neymark, Leonid A.

    2012-01-01

    Characteristics of host rocks, secondary minerals, and fluids would affect the transport of radionuclides from a previously proposed repository at Yucca Mountain, Nevada. Minerals in the Yucca Mountain tuffs that are important for retarding radionuclides include clinoptilolite and mordenite (zeolites), clay minerals, and iron and manganese oxides and hydroxides. Water compositions along flow paths beneath Yucca Mountain are controlled by dissolution reactions, silica and calcite precipitation, and ion-exchange reactions. Radionuclide concentrations along flow paths from a repository could be limited by (1) low waste-form dissolution rates, (2) low radionuclide solubility, and (3) radionuclide sorption onto geological media.

  14. PABLM: a computer program to calculate accumulated radiation doses from radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Napier, B.A.; Kennedy, W.E. Jr.; Soldat, J.K.

    1980-03-01

    A computer program, PABLM, was written to facilitate the calculation of internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. This report contains details of mathematical models used and calculational procedures required to run the computer program. Radiation doses from radionuclides in the environment may be calculated from deposition on the soil or plants during an atmospheric or liquid release, or from exposure to residual radionuclides in the environment after the releases have ended. Radioactive decay is considered during the release of radionuclides, after they are deposited on the plants or ground, and during holdup of food after harvest. The radiation dose models consider several exposure pathways. Doses may be calculated for either a maximum-exposed individual or for a population group. The doses calculated are accumulated doses from continuous chronic exposure. A first-year committed dose is calculated as well as an integrated dose for a selected number of years. The equations for calculating internal radiation doses are derived from those given by the International Commission on Radiological Protection (ICRP) for body burdens and MPC's of each radionuclide. The radiation doses from external exposure to contaminated water and soil are calculated using the basic assumption that the contaminated medium is large enough to be considered an infinite volume or plane relative to the range of the emitted radiations. The equations for calculations of the radiation dose from external exposure to shoreline sediments include a correction for the finite width of the contaminated beach.

  15. PABLM: a computer program to calculate accumulated radiation doses from radionuclides in the environment

    International Nuclear Information System (INIS)

    Napier, B.A.; Kennedy, W.E. Jr.; Soldat, J.K.

    1980-03-01

    A computer program, PABLM, was written to facilitate the calculation of internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. This report contains details of mathematical models used and calculational procedures required to run the computer program. Radiation doses from radionuclides in the environment may be calculated from deposition on the soil or plants during an atmospheric or liquid release, or from exposure to residual radionuclides in the environment after the releases have ended. Radioactive decay is considered during the release of radionuclides, after they are deposited on the plants or ground, and during holdup of food after harvest. The radiation dose models consider several exposure pathways. Doses may be calculated for either a maximum-exposed individual or for a population group. The doses calculated are accumulated doses from continuous chronic exposure. A first-year committed dose is calculated as well as an integrated dose for a selected number of years. The equations for calculating internal radiation doses are derived from those given by the International Commission on Radiological Protection (ICRP) for body burdens and MPC's of each radionuclide. The radiation doses from external exposure to contaminated water and soil are calculated using the basic assumption that the contaminated medium is large enough to be considered an infinite volume or plane relative to the range of the emitted radiations. The equations for calculations of the radiation dose from external exposure to shoreline sediments include a correction for the finite width of the contaminated beach

  16. Geochemistry and radionuclide migration

    International Nuclear Information System (INIS)

    Isherwood, D.

    1978-01-01

    Theoretically, the geochemical barrier can provide a major line of defense in protecting the biosphere from the hazards of nuclear waste. The most likely processes involved are easily identified. Preliminary investigations using computer modeling techniques suggest that retardation is an effective control on radionuclide concentrations. Ion exchange reactions slow radionuclide migration and allow more time for radioactive decay and dispersion. For some radionuclides, solubility alone may limit concentrations to less than the maximum permissible now considered acceptable by the Federal Government. The effectiveness of the geochemical barrier is ultimately related to the repository site characteristics. Theory alone tells us that geochemical controls will be most efficient in an environment that provides for maximum ion exchange and the precipitation of insoluble compounds. In site selection, consideration should be given to rock barriers with high ion exchange capacity that might also act as semi-permeable membranes. Also important in evaluating the site's potential for effective geochemical controls are the oxidation potentials, pH and salinity of the groundwater

  17. Statistical analysis of fallout radionuclides transfer to paddy-field rice

    International Nuclear Information System (INIS)

    Takahashi, T.; Morisawa, S.; Inoue, Y.

    1996-01-01

    Radionuclides released from nuclear facilities to atmosphere are transported through various pathways in biosphere and cause human exposure. Among these radionuclides transfer pathways, an ingestion of crops containing radionuclides is one of the dominant pathway for human exposure. For the safety assessment of nuclear facilities, it is important to understand the behavior of radionuclides in agricultural environment and to describe them in a mathematical model. In this paper, a statistical model is proposed for estimating the concentration of fallout radionuclides in paddy-field rice, the staple food for Japanese people. For describing behavior of fallout radionuclides in a paddy-field, a dynamic model and a statistical model have been proposed respectively. The model used in this study has been developed assuming that the amount of radionuclides transfer to brown rice (hulled rice) or polished rice through direct deposition of airborne radionuclides (the direct deposition pathway) and root uptake from a paddy soil (the root uptake pathway) are proportional to the deposition flux of radionuclides and concentration of radionuclides in paddy soil respectively. That is, the model has two independent variables; the deposition flux of radionuclides and the concentration of radionuclides in the paddy soil, and has single dependent variable; the concentration of radionuclides in brown rice or polished rice. The regression analysis is applied by using environmental monitoring data. Then the distribution of radionuclides between rice-bran (skin part of rice crop) and polished rice (core part) through both the direct deposition pathway and the root uptake pathway are evaluated by the model. (author)

  18. Phytoremediation of soil contaminated with low concentrations of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Entry, J A; Vance, N C; Hamilton, M A; Zabowski, D; Watrud, L S; Adriano, D C [Auburn University, Auburn, AL (United States). Dept. of Agronomy and Soils

    1996-03-01

    Ecsosytems throughout the world have been contaminated with radionuclides by above-ground nuclear testing, nuclear reactor accidents and nuclear power generation. Radioisotopes characteristics of nuclear fission, such as {sup 137}Cs and {sup 90}Sr, that are released into the environment can become more concentrated as they move up the food chain often becoming human health hazards. Natural environmental processes will redistribute long lived radionuclides that are released into the environment among soil, plants and wildlife. Numerous studies have shown that {sup 137}Cs and {sup 90}Sr are not removed from the top 0.4 metres of soil even under high rainfall, and migration rate from the top few centimetres of soil is slow. The top 0.4 meters of the soil is where plant roots actively accumulate elements. Since plants are known to take up and accumulate {sup 137}Cs and {sup 90}Sr, removal of these radionuclides from contaminated soils by plants could provide a reliable and economical method of remediation. One approach is to use fast growing plants inoculated with mycorrhizal fungi combined with soil organic amendments to maximize the plant accumulation and removal of radionuclides from contaminated soils, followed by harvest of above-ground portion of the plants. High temperature combustion would be used to oxidize plant material concentrating {sup 137}Cs and {sup 90}Sr in ash for disposal. When areas of land have been contaminated with radionuclides are large, using energy intensive engineering solutions to mediate huge volumes of soil is not feasible or economical. Plants are proposed as a viable and cost effective method to remove radionuclides from the soils that have been contaminated by nuclear testing and nuclear reactor accidents. 40 refs.

  19. PABLM, Doses from Radioactive Releases to Atmosphere and Food Chain

    International Nuclear Information System (INIS)

    Napier, B.A.; Kennedy, W.E. Jr.; Soldat, J.K.

    1983-01-01

    1 - Description of problem or function: PABLM calculates internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. Radiation doses from radionuclides in the environment may be calculated from deposition on the soil or plants during an atmospheric or liquid release, or from exposure to residual radionuclides after the releases have ended. Radioactive decay is considered during the release, after deposition, and during holdup of food after harvest. The radiation dose models consider exposure to radionuclides deposited on the ground or crops from contaminated air or irrigation water, radionuclides in contaminated drinking water, aquatic foods raised in contaminated water, and radionuclides in bodies of water and sediments where people might fish, boat, or swim. For vegetation, the radiation dose model considers both direct deposition and uptake through roots. Doses may be calculated for either a maximum-exposed individual or for a population group. The program is designed to calculate accumulated radiation doses from the chronic ingestion of food products that contain radionuclides and doses from the external exposure to radionuclides in the environment. A first-year committed dose is calculated as well as an integrated dose for a selected number of years. 2 - Method of solution: A chain decay scheme including branching for transitions to and from isomeric states is used for radioactive decay. The equations for calculating internal radiation doses are derived from those given by the International Commission on Radio- logical Protection (ICRP) for body burdens and the maximum possible concentration (MPC) for each radionuclide. These doses are calculated as a function of radionuclide concentration in food products, ingestion rates, and a radionuclide-specific dose- commitment factor. Radiation doses from external exposure to contaminated water and soil are calculated using the basic assumption

  20. Multibarrier system preventing migration of radionuclides from radioactive waste repository

    Directory of Open Access Journals (Sweden)

    Olszewska Wioleta

    2015-09-01

    Full Text Available Safety of radioactive waste repositories operation is associated with a multibarrier system designed and constructed to isolate and contain the waste from the biosphere. Each of radioactive waste repositories is equipped with system of barriers, which reduces the possibility of release of radionuclides from the storage site. Safety systems may differ from each other depending on the type of repository. They consist of the natural geological barrier provided by host rocks of the repository and its surroundings, and an engineered barrier system (EBS. The EBS may itself comprise a variety of sub-systems or components, such as waste forms, canisters, buffers, backfills, seals and plugs. The EBS plays a major role in providing the required disposal system performance. It is assumed that the metal canisters and system of barriers adequately isolate waste from the biosphere. The evaluation of the multibarrier system is carried out after detailed tests to determine its parameters, and after analysis including mathematical modeling of migration of contaminants. To provide an assurance of safety of radioactive waste repository multibarrier system, detailed long term safety assessments are developed. Usually they comprise modeling of EBS stability, corrosion rate and radionuclide migration in near field in geosphere and biosphere. The principal goal of radionuclide migration modeling is assessment of the radionuclides release paths and rate from the repository, radionuclides concentration in geosphere in time and human exposure to ionizing radiation

  1. Radionuclides in drinking water: the recent legislative requirements of the European Union

    International Nuclear Information System (INIS)

    Grande, Sveva; Risica, Serena

    2015-01-01

    In November 2013, a new EURATOM Directive was issued on the protection of public health from the radionuclide content in drinking water. After introducing the contents of the Directive, the paper analyses the hypotheses about drinking water ingestion adopted in documents of international and national organizations and the data obtained from national/regional surveys. Starting from the Directive’s parametric value for the Indicative Dose, some examples of derived activity concentrations of radionuclides in drinking water are reported for some age classes and three exposure situations, namely, (i) artificial radionuclides due to routine water release from nuclear power facilities, (ii) artificial radionuclides from nuclear medicine procedures, and (iii) naturally occurring radionuclides in drinking water or resulting from existing or past NORM industrial activities. (paper)

  2. Peculiarities of radionuclide transfer to plants

    International Nuclear Information System (INIS)

    Butkus, D.; Andriulaityte, I.; Luksiene, B.; Druteikiene, R.

    2003-01-01

    The biosphere and its interacting components (air, soil, bottom sediments, flora, fauna, human beings) are constantly affected by ionizing radiation. One of the ionizing radiation sources is noble radioactive gas that is continually released into the environment because of the normal operation of nuclear power plants (short-lived and long-lived noble gas) and nuclear fuel-reprocessing plants (long-lived noble gas). Another source is related to nuclear tests and the Chernobyl NPP accident, when long-lived gaseous and aerosol radionuclides ( 85 Kr, transuranics, 137 Cs, 90 Sr, etc) were spread in all environmental systems. In order to evaluate the mechanism of radionuclide transfer to plants, model experimental investigation using gaseous 85 Kr and ionic state 137 Cs was undertaken. For this purpose specific chambers with defined physical parameters were applied. The gained tentative results show the importance of these experiments for the estimation of radionuclide transfer to plants and for the prognosis of human internal irradiation. (author)

  3. Interactions of radionuclides in water, particulates, and oysters in the discharge canal of a nuclear power plant

    International Nuclear Information System (INIS)

    Harrison, F.L.; Wong, K.M.; Heft, R.E.

    1976-01-01

    This study was designed to provide data for dynamic modeling of radioactive pollutants in marine ecosystems adjacent to nuclear power plants. The data are relevant to the dynamics of radionuclide transfer among seawater, suspended particulates, sediments, and biota. Gamma-emitting radionuclides ( 54 Mn, 60 Co, 65 Zn, and 137 Cs) were followed in the water and particulates, as well as in oysters introduced into the discharge canal of the boiling water reactor of the Humboldt Bay Power Plant near Eureka, California. The liquid waste was introduced into the canal at irregular intervals and contained radionuclides at extremely low but variable concentrations. Radionuclides were determined in the oysters, water, and particulates after single releases (over about 6 hr) and over a long series of releases

  4. A simplified model for calculating atmospheric radionuclide transport and early health effects from nuclear reactor accidents

    International Nuclear Information System (INIS)

    Madni, I.K.; Cazzoli, E.G.; Khatib-Rahbar, M.

    1995-01-01

    During certain hypothetical severe accidents in a nuclear power plant, radionuclides could be released to the environment as a plume. Prediction of the atmospheric dispersion and transport of these radionuclides is important for assessment of the risk to the public from such accidents. A simplified PC-based model was developed that predicts time-integrated air concentration of each radionuclide at any location from release as a function of time integrated source strength using the Gaussian plume model. The solution procedure involves direct analytic integration of air concentration equations over time and position, using simplified meteorology. The formulation allows for dry and wet deposition, radioactive decay and daughter buildup, reactor building wake effects, the inversion lid effect, plume rise due to buoyancy or momentum, release duration, and grass height. Based on air and ground concentrations of the radionuclides, the early dose to an individual is calculated via cloudshine, groundshine, and inhalation. The model also calculates early health effects based on the doses. This paper presents aspects of the model that would be of interest to the prediction of environmental flows and their public consequences

  5. Evaluating the radiation environment around a nuclear power station with unmonitored radionuclide release

    International Nuclear Information System (INIS)

    Bondarev, A.A.; Dibobes, I.K.; Pyuskyulan, K.I.

    1986-01-01

    This paper describes the radiation monitoring system at (RMS) at the Armenian nuclear power station; the environmental monitoring program includes measuring the gamma radiation around the station, determining radionuclide contents in air and fallout, and also in surface water and ground water, in water plants and bottom sediments, in soil and plants and also in local agricultural products. The RMS monitors gas-aerosol releases and effluents from the station. The radius of the monitored zone is 25 km. The gamma radiation is measured by IKS dosemeters and SRP-68-01 portable instruments. The air is monitored by six stationary aspriation systems at distances of 1, 5, 6, 11, 14, 15 and 50 km and 28 planchette cells. The RMS records virtually all the mean monthly and mean annual fluctuations in the global background. In seven years of operation at the Armenian station, only Ca 137 and Sr 90 from global fallout together with Be 7 of cosmogenic origin have been observed in air apart from two cases. In 1981, air samples taken with the aspirators and combined over a quarter showed Ce 141, Ce 144, Ru 106, Ru 103, Nb 95 and Zr 95. The concentrations of these are presented

  6. Rate setting and regulatory control of the radionuclides content in foodstuffs

    International Nuclear Information System (INIS)

    Shandala, N. K.; Savskin, M. N.; Petukhova, E. V.; Novikova, N. Y.; Titov, A. V.

    2004-01-01

    The concept of rate setting, standardisation and regulatory control of the radionuclides content in foodstuffs consists in the following: ? the normative standards concern to 90Sr and 137Cs as biologically significant radionuclides; ? the internal exposure dose from ingestion intake of radionuclides with food should not exceed meaning of 1 mSv a-1 which is the intervention exception level concerning trading foodstuffs; ? for few consumed foodstuffs (wild berries, mushrooms, teas) is established, that the dose caused by their consumption is outside of dose limits of 1 mSv a-1 and it should not exceed 1 % for each product; ? the nutrition structure of population including seven basic components of a diet (bread and grain products, dairy products, potatoes, vegetables, meat, fish, fruit and berries) is taken into account as a source of ingestion intake of the radionuclides; ? The conformity to the established standard is determined on a parameter ?f the summary contents of 90Sr and 137Cs in foodstuff. With the purpose of the operative control of an internal exposure of population the permissible levels of specific activity of 90Sr and 137Cs in more than 120 kinds of foodstuff were developed. These standards are obligatory in Russia for domestic and imported foodstuffs. So, permissible levels of specific activity of 90Sr and 137Cs in bread make, accordingly, 20 and 40 Bq kg-1; in milk - 25 and 100 Bq kg-1; in meat - 50 and 160 Bq kg-1; in potatoes and vegetables - 40 and 120 Bq kg-1. Monitoring of contamination of foodstuffs by 137Cs and 90Sr is one of the basic measures on maintenance of radiation safety of population in Russia. State system of sanitary-epidemiological control carries out constant supervision over the content of the radionuclides in food production. By the carried out researches was shown that true levels of the contents of 90Sr or 137Cs in the main foodstuffs in territory of Russia, except for the territories, injures of the radiation accidents, make

  7. Dose-rate conversion factors for external exposure to photon and electron radiation from radionuclides occurring in routine releases from nuclear fuel cycle facilities

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1980-01-01

    Dose-rate conversion factors for external exposure to photon and electron radiation are calculated for 240 radionuclides of potential importance in routine releases from nuclear fuel cycle facilities. Exposure modes considered are immersion in contaminated air, immersion in contaminated water, and irradiation from a contaminated ground surface. For each exposure mode, dose-rate conversion factors for photons and electrons are calculated for tissue-equivalent material at the body surface of an exposed individual. Dose-rate conversion factors for photons only are calculated for 22 body organs. (author)

  8. Radionuclide getters in the near-field chemistry of repositories

    International Nuclear Information System (INIS)

    Holland, T.R.; Lee, D.J.

    1993-01-01

    The ultimate release of radionuclides from a radioactive waste repository will depend upon the natural and man-made barriers surrounding the site. An opportunity exists to enhance natural radionuclide retention through improved sorption, by the use of suitable additives applied to the repository backfill material. This programme of work was designed to identify problem isotopes, to search for suitable materials to enhance their retention and ultimately to provide, through experimental studies, an understanding of their effectiveness under repository conditions. (Author)

  9. Deposition and interception of radionuclides. Current knowledge and future requirements

    International Nuclear Information System (INIS)

    1998-12-01

    Following an accidental or routine release of radionuclides into the environment, a good knowledge of deposition processes is necessary in order to accurately predict the radiation dose to members of the public. In order to understand the environmental impact of released radionuclides and their transfer through the environment, including the food chain to man, there have been numerous studies on deposition of radionuclides to a range of surfaces such as bare soil, crops, forests, water bodies and urban surfaces. The RADREM committee provides a forum for liaison on UK research and monitoring in the areas of radioactive substances and radioactive waste management. RADREM has set up four sub-committees to cover issues related to radioactivity in the atmospheric, terrestrial and aquatic environments as well as those related radioactive waste management. One of the sub-committee tasks is to organise seminars and workshops on specific topics of interest. The first of these was the workshop on 'Deposition and Interception of Radionuclides: Current knowledge and future requirements' organised last year by the Ministry of Agriculture, Fisheries and Food (MAFF), acting as secretariat for the Terrestrial Environment Sub-Committee (TESC) of RADREM. The intent of this workshop was to provide an opportunity to exchange information on deposition-related aspects between representatives from various interested parties including government, regulatory bodies, industry and research organisations. Through presentations and discussions, this workshop addressed current developments in the areas of deposition and interception of radionuclides by various surfaces and served to identify areas which need further research. Papers were presented on various aspects of deposition and interception of radionuclides including deposition into grass, fruits and other crops as well as deposition into urban areas and forests

  10. Release procedures and disposal of radioactive residual substances at the Medical University Hanover (MHH)

    International Nuclear Information System (INIS)

    Scheller, F.; Behrendt, R.; Harke, H.

    2005-01-01

    The disposal of all radioactive residual packages of the MHH is regulated by the German radiation protection ordinance from 26 th July 2001; shown in appendix III, table 1, column 5: unrestricted release of solid materials and liquids. All radioactive waste packages are collected and handled by the central MHH department for radiation protection. They are sorted for type, nuclide and specific radioactivity. A few packages can directly be released as conventional waste after performing incoming measurements showing very low activity concentrations. Longer living radionuclides with specific activities above the release limits have to be delivered to the national waste disposal. For direct measurements of gamma-emitting radionuclides we use two in-situ-measuring units (ISOCS, Canberra) and a special release unit with 9 plastic scintillators in a fixed geometry (FR-9 PVT, MED Medizintechnik). Fluid beta-emitting radionuclides are measured by taking a fraction and using liquid scintillation counting (LSC). Solid beta-emitting radionuclides activity are calculated. (orig.)

  11. EPICS application source/release control

    International Nuclear Information System (INIS)

    Zieman, B.; Anderson, J.; Kraimer, M.

    1995-01-01

    This manual describes a set of Application Source/Release Control tools (appSR) that can be used to develop software for EPICS based control systems. The Application Source/Release Control System (appSR) has been unbundled from base EPICS and is now available as an EPICS extension. Due to this unbundling, two new directories must be added to a user's path (see section ''Environment'' on page 3 for more information) and a new command getapp must be issued after the getrel command to get a specific version of appSR (see section ''Creating The Initial Application System Area'' on page 7 for more information). It is now required that GNU make version 3.71 or later be used for makes instead of SUN make. Users should now type gmake instead of make

  12. Identification of key radionuclides in a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Barney, G.S.; Wood, B.J.

    1980-05-01

    Radionuclides were identified which appear to pose the greatest potential hazard to man during long-term storage of nuclear waste in a repository mined in the Columbia Plateau basalt formation. The criteria used to select key radionuclides were as follows: quantity of radionuclide in stored waste; biological toxicity; leach rate of the wastes into groundwater; and transport rate via groundwater flow. The waste forms were assumed to be either unreprocessed spent fuel or borosilicate glass containing reprocessed high-level waste. The nuclear waste composition was assumed to be that from a light water reactor. Radionuclides were ranked according to quantity, toxicity, and release rate from the repository. These rankings were combined to obtain a single list of key radionuclides. The ten most important radionuclides in order of decreasing hazard are: 99 Tc, 129 I, 237 Np, 226 Ra, 107 Pd, 230 Th, 210 Pb, 126 Sn, 79 Se, and 242 Pu. Safety assessment studies and the design of engineered barriers should concentrate on containment of radionuclides in this list

  13. Comprehensive cooling water study annual report. Volume IV: radionuclide and heavy metal transport, Savannah River Plant

    International Nuclear Information System (INIS)

    Gladden, J.B.; Lower, M.W.; Mackey, H.E.; Specht, W.L.; Wilde, E.W.

    1985-07-01

    The principal sources of tritium, radiocesium, and radiocobalt in the environment at the Savannah River Plant have been reactor area effluent discharges to onsite streams. Radioactive releases began in 1955, with the period of major reactor releases occurring between 1955 and 1968. Since the early 1970s, releases, except for tritium releases, have been substantially reduced. Radioisotope liquid releases resulted specifically from leaching of reactor fuel elements with cladding failures which exposed the underlying fuel to water. The direct sources of these releases were heat exchanger cooling water, spent fuel storage and disassembly basin effluents, and process water from each of the reactor areas. Offsite radiochemical monitoring of water and sediment at upriver and downriver water treatment facilities indicates that SRP contributions of gamma-emitting radionuclide levels present at these facilities are minute. Tritium in water attributable to SRP operations is routinely detected at the downriver facilities; however, total alpha and nonvolatile beta concentrations attributable to SRP liquid releases are not detected at the downriver facilities. The historic material balance calculated for onsite releases of tritium transported to the Savannah River exhibits a high accounting of tritium released. Other radionuclides released to onsite streams have primarily remained in onsite floodplains. Radionuclide releases associated with reactor operations are derived primarily from disassembly basin water releases in the reactor areas and historically have been the major source of radioactivity released to onsite streams. The movement and interaction of these releases have been governed by cooling water discharges. Liquid releases continue to meet DOE concentration guides for the various radioisotopes in onsite streams and in the Savannah River

  14. Formulation and evaluation of gas release scenarios for the silo in Swedish Final Repository for Radioactive Waste (SFR)

    International Nuclear Information System (INIS)

    Carlsson, J.; Moreno, L.

    1992-01-01

    The Swedish Final Repository for Radioactive Waste (SFR) has been in operation since 1988 and is located in the crystalline rock, 60 m below the Baltic Sea. In the licensing procedure for the SFR the safety assessment has been complemented with a detailed scenario analysis of the performance of the repository. The scenarios include the influence on radionuclide release by gas formation and gas transport processes in the silo. The overall conclusion is that the release of most radionuclides from the silo is only marginally affected by the formation and release of gas, even for scenarios considering unexpected events. The largest effects were found for short-lived radionuclides and radionuclides that have no or low sorption ability. Except for very extreme scenarios for the silo the overall impact from repository on the environment is by far dominated by the release of radionuclides from the rock vaults. 10 refs., 6 figs

  15. The distribution and abundance of gamma emitting radionuclides in Lake Ontario sediments

    International Nuclear Information System (INIS)

    McKinley, R.S.

    1985-03-01

    The distribution of gamma emitting radionuclides in Lake Ontario sediments was investigated. Samples were collected using a systematic design in the vicinity of Pickering and Darlington, and supplemented by lakewide offshore samples. Naturally occurring 40 K was the predominant source of gamma activity. 60 Co was the only potentially CANDU released radionuclide which showed a distributional association with the Pickering 'A' NGS discharge

  16. Monitoring of Radionuclide Contamination in Food Samples in Malaysia due to Daiichi Reactor Accident in Fukushima, Japan

    International Nuclear Information System (INIS)

    Nurrul Assyikeen Mohd Jaffary; Abdul Kadir Ishak; Wo, Y.M.

    2011-01-01

    On March 11, 2011, a serious accident occurred in Daiichi nuclear reactor plant, Fukushima, Japan which caused radioactive materials been released into the atmosphere in the form of aerosols and dust particles. Sea water around the plant was also found contaminated with high radioactivity readings. These radioactive materials could be transported by the winds and ocean current across international borders and cannot be controlled by human. Besides a continuous monitoring activity of radionuclide content in the air and sea water that need to be conducted by the authorities, Malaysia should also control the entry of radionuclide through contaminated food ingestion by human. Radionuclide I-131, Cs-134 and Cs-137 were used as a counter-measure of pollution levels and counted with gamma spectrometry using standard analysis method suggested by AOAC International. In this paper, details description of the role of Radiochemical and Environment Group, Nuclear Malaysia who's responsible in analyzing the radioactivity in the food samples due to Fukushima Daiichi, Japan accident was included. Also discussed are the radioactivity limit adopted and analysis results from this monitoring. (author)

  17. Estimation of radiological consequences from accidental iodine releases at nuclear power plants

    International Nuclear Information System (INIS)

    Drozdovitch, V.V.

    2001-01-01

    The radiological consequences of a beyond design-basis accident at an NPP for a VVER-1000 reactor are evaluated. Using the software code COSYMA and accounting for radioiodine activity release to the atmosphere at the early stage of the accident, the radionuclide concentration in air and ground deposition densities were estimated. Inhalation and ingestion thyroid doses to different population sub-groups have been calculated. Using modern knowledge about the risk of radiation-induced cancer, the radiological danger of radionuclides released is evaluated for different exposure pathways. Thyroid doses and risk was estimated for populations living at different distances from the NPP. The comparative analysis of exposure pathways and radiological danger of the radionuclides in release during early and intermediate stage of accident has conducted. (author)

  18. Radionuclide metrology: traceability and response to a radiological accident

    Energy Technology Data Exchange (ETDEWEB)

    Tauhata, L.; Cruz, P.A.L. da; Silva, C.J. da; Delgado, J.U.; Oliveira, A.E. de; Oliveira, E.M. de; Poledna, R.; Loureiro, J. dos S.; Ferreira Filho, A.L.; Silva, R.L. da; Filho, O. L.T.; Santos, A.R.L. dos; Veras, E.V. de; Rangel, J. de A.; Quadros, A.L.L.; Araújo, M.T.F. de; Souza, P.S. de; Ruzzarim, A.; Conceição, D.A. da; Iwahara, A., E-mail: palcruz@ird.gov.br [Instituto de Radioproteção e Dosimetria (LNMRI/IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiações Ionizantes

    2017-07-01

    In the case of a radiological accident, there are characteristic phases: discovery and initial assistance with first aid; the triage and monitoring of the affected population; the release of the affected people; forward the victims to medical care; as well as the preparation of the report on the accident. In addition, studies and associated researches performed in the later period. Monitors, dosimeters and measuring systems should be calibrated by contaminating radionuclide standards. The radioactive sources used must be metrologically reliable. In Brazil, this function is performed by LNMRI/IRD/CNEN, designated by INMETRO, which Radionuclide Metrology Laboratory is responsible for the standardization and supply of radioactive sources in diverse geometries and matrices. This laboratory has a stock of radionuclide solutions with controlled environmental variables for the preparation of sources, which are calibrated and standardized by mean of primary and secondary systems. It is also responsible for the dissemination of standards and, in order to establish the metrological traceability of national standards, participates in international key-comparisons promoted by BIPM and regional metrology organizations. Internally, it promotes the National Comparison Programs for laboratories for the analysis of environmental samples and the traceability for producing centers of radiopharmaceuticals and Nuclear Medicine Services in the country. The paper presents the demand for {sup 137}Cs related to the radioactive accident in Goiania/Brazil and the significant results for the main radionuclides standardized by the Radionuclide Metrology Laboratory for international key-comparisons and national comparisons to provide metrological traceability. With the obtained results, the LNMRI of Brazil integrates the international metrology BIPM network and fulfills its function of supplying, with about a hundred of radioactive standards, the country's needs in different applications

  19. Radionuclide metrology: traceability and response to a radiological accident

    International Nuclear Information System (INIS)

    Tauhata, L.; Cruz, P.A.L. da; Silva, C.J. da; Delgado, J.U.; Oliveira, A.E. de; Oliveira, E.M. de; Poledna, R.; Loureiro, J. dos S.; Ferreira Filho, A.L.; Silva, R.L. da; Filho, O. L.T.; Santos, A.R.L. dos; Veras, E.V. de; Rangel, J. de A.; Quadros, A.L.L.; Araújo, M.T.F. de; Souza, P.S. de; Ruzzarim, A.; Conceição, D.A. da; Iwahara, A.

    2017-01-01

    In the case of a radiological accident, there are characteristic phases: discovery and initial assistance with first aid; the triage and monitoring of the affected population; the release of the affected people; forward the victims to medical care; as well as the preparation of the report on the accident. In addition, studies and associated researches performed in the later period. Monitors, dosimeters and measuring systems should be calibrated by contaminating radionuclide standards. The radioactive sources used must be metrologically reliable. In Brazil, this function is performed by LNMRI/IRD/CNEN, designated by INMETRO, which Radionuclide Metrology Laboratory is responsible for the standardization and supply of radioactive sources in diverse geometries and matrices. This laboratory has a stock of radionuclide solutions with controlled environmental variables for the preparation of sources, which are calibrated and standardized by mean of primary and secondary systems. It is also responsible for the dissemination of standards and, in order to establish the metrological traceability of national standards, participates in international key-comparisons promoted by BIPM and regional metrology organizations. Internally, it promotes the National Comparison Programs for laboratories for the analysis of environmental samples and the traceability for producing centers of radiopharmaceuticals and Nuclear Medicine Services in the country. The paper presents the demand for 137 Cs related to the radioactive accident in Goiania/Brazil and the significant results for the main radionuclides standardized by the Radionuclide Metrology Laboratory for international key-comparisons and national comparisons to provide metrological traceability. With the obtained results, the LNMRI of Brazil integrates the international metrology BIPM network and fulfills its function of supplying, with about a hundred of radioactive standards, the country's needs in different applications

  20. Vegetation fires, smoke emissions, and dispersion of radionuclides in the chernobyl exclusion zone

    Science.gov (United States)

    Wei Min Hao; Oleg O. Bondarenko; Sergiy Zibtsev; Diane Hutton

    2009-01-01

    The accident of the Chernobyl nuclear power plant (ChNPP) in 1986 was probably the worst environmental disaster in the past 30 years. The fallout and accumulation of radionuclides in the soil and vegetation could have long-term impacts on the environment. Radionuclides released during large, catastrophic vegetation fires could spread to continental Europe, Scandinavia...

  1. Radionuclide distribution in LWR [light-water reactor] spent fuel

    International Nuclear Information System (INIS)

    Guenther, R.J.; Blahnik, D.E.; Thomas, L.E.; Baldwin, D.L.; Mendel, J.E.

    1990-09-01

    The Materials Characterization Center (MCC) at Pacific Northwest Laboratory (PNL) provides well-characterized spent fuel from light-water reactors (LWRs) for use in laboratory tests relevant to nuclear waste disposal in the proposed Yucca Mountain repository. Interpretation of results from tests on spent fuel oxidation, dissolution, and cladding degradation requires information on the inventory and distribution of radionuclides in the initial test materials. The MCC is obtaining this information from examinations of Approved Testing Materials (ATMs), which include spent fuel with burnups from 17 to 50 MWd/kgM and fission gas releases (FGR) from 0.2 to 18%. The concentration and distribution of activation products and the release of volatile fission products to the pellet-cladding gap and rod plenum are of particular interest because these characteristics are not well understood. This paper summarizes results that help define the 14 C inventory and distribution in cladding, the ''gap and grain boundary'' inventory of radionuclides in fuels with different FGRs, and the structure and radionuclide inventory of the fuel rim region within a few hundred micrometers from the fuel edge. 6 refs., 5 figs., 1 tab

  2. Transfer into the biosphere of radionuclides released from deep storage of radioactive wastes. Bibliographical study

    International Nuclear Information System (INIS)

    Guedon, V.; Siclet, F.

    1995-03-01

    Most countries with civilian nuclear programs today are encountering difficulty in implementing a nuclear waste management policy that is both technically safe in the long term and accepted by the public. To meet both criteria, the solution most generally envisaged is deep storage either of untreated spent nuclear fuel or of highly radioactive wastes resulting from reprocessing. In order to predict the potential impact of such storage on man, one needs to understand the path followed by radionuclides in the geosphere, and later in the biosphere. Given the time scales involved and the critical nature of the elements concerned, it is indispensable to turn to mathematical modeling of the phenomena. This, however, does not preclude the essential need for in-depth knowledge of the phenomena and of the physico-chemical characteristics of radionuclides. This report presents what is hoped to be a complete inventory of the radionuclides contained in ''high level'' wastes (categories B AND C). The elements concerned in studies on deep storage are essentially long-life radionuclides (both actinides and certain fission and activation products). Their physico-chemical characteristics and their behavior in various ecological compartments are examined. Bibliographical data bearing on: solubility (in an oxidizing, reducing medium), distribution factors (water/rock-sediment-soil), concentration and transfer factors (in aquatic and terrestrial mediums), dose conversion factors (in the case of internal and external irradiation), principal paths of exposure for each radionuclide studied, are presented in this report. Initial results from international projects to model what happens to radionuclides in the biosphere are also presented. In general, they are optimistic as to the future, but nonetheless point to a need to improve the conceptual base of the models, to ensure that all major phenomena and processes are taken into consideration and to examine any possible amplification

  3. Overview study of LNG release prevention and control systems

    Energy Technology Data Exchange (ETDEWEB)

    Pelto, P.J.; Baker, E.G.; Holter, G.M.; Powers, T.B.

    1982-03-01

    The liquefied natural gas (LNG) industry employs a variety of release prevention and control techniques to reduce the likelihood and the consequences of accidental LNG releases. A study of the effectiveness of these release prevention and control systems is being performed. Reference descriptions for the basic types of LNG facilities were developed. Then an overview study was performed to identify areas that merit subsequent and more detailed analyses. The specific objectives were to characterize the LNG facilities of interest and their release prevention and control systems, identify possible weak links and research needs, and provide an analytical framework for subsequent detailed analyses. The LNG facilities analyzed include a reference export terminal, marine vessel, import terminal, peakshaving facility, truck tanker, and satellite facility. A reference description for these facilities, a preliminary hazards analysis (PHA), and a list of representative release scenarios are included. The reference facility descriptions outline basic process flows, plant layouts, and safety features. The PHA identifies the important release prevention operations. Representative release scenarios provide a format for discussing potential initiating events, effects of the release prevention and control systems, information needs, and potential design changes. These scenarios range from relatively frequent but low consequence releases to unlikely but large releases and are the principal basis for the next stage of analysis.

  4. Migration of radionuclide chains in subseabed disposal

    International Nuclear Information System (INIS)

    Ray, A.K.; Nuttall, H.E.

    1982-01-01

    In this study of subseabed disposal, the two dimensional (axial and radial) migration of radionuclide chains released from a canister located in a sedimentary layer bounded at the top by the ocean and at the bottom by an impermeable basalt zone is analyzed to determine the escape rate of radionuclides into the seawater. Analytical solutions have been derived to represent the transient concentration profiles within the sediment, flux and discharge rates to the water column of each member present in a decay chain. Using the properties of chain members present in actinide decay systems, the effects of half-life, adsorption equilibrium and other relevant parameters are elucidated. 4 figures, 1 table

  5. Stimuli-Responsive Materials for Controlled Release Applications

    KAUST Repository

    Li, Song

    2015-04-01

    The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. To address this outstanding problem, the design and fabrication of stimuli-responsive materials are pursued to guarantee the controlled release of cargo at a specific time and with an accurate amount. Upon applying different stimuli such as light, magnetic field, heat, pH change, enzymes or redox, functional materials change their physicochemical properties through physical transformation or chemical reactions, allowing the release of payload agents on demand. This dissertation studied three stimuli-responsive membrane systems for controlled release from films of macro sizes to microcapsules of nano sizes. The first membrane system is a polymeric composite film which can decrease and sustain diffusion upon light irradiation. The photo-response of membranes is based on the photoreaction of cinnamic derivatives. The second one is composite membrane which can improve diffusion upon heating. The thermo-response of membranes comes from the volume phase transition ability of hydrogels. The third one is microcapsule which can release encapsulated agents upon light irradiation. The photo-response of capsules results from the photoreaction of nitrobenzyl derivatives. The study on these membrane systems reveals that stimuli-responsive release can be achieved by utilizing different functional materials on either macro or micro level. Based on the abundant family of smart materials, designing and fabricating stimuli-responsive systems shall lead to various advanced release processes on demand for biomedical applications.

  6. Subject-3: Study on migration of radionuclides released into terrestrial and aquatic environment after nuclear accident

    International Nuclear Information System (INIS)

    Amano, H.; Matsunaga, T.; Ueno, T.; Nagao, S.; Yanase, N.; Tkachenko, Yu.

    2001-01-01

    Subject-3 has been focused on the migration behavior of long-lived radionuclides in the terrestrial surface environment, especially in connection with their chemical and physical forms. Migration behavior of radionuclides is strongly affected with their chemical and physical forms (for example; Gunten and Benes 1995). One of the two categories in Subject-3 consists of migration from surface soils including aging effects of hot particles, plant uptake from contaminated soils, and resuspension of radionuclides. The other is run off by river system, considering the role of organic materials. (author)

  7. Subject-3: Study on migration of radionuclides released into terrestrial and aquatic environment after nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Amano, H.; Matsunaga, T.; Ueno, T.; Nagao, S.; Yanase, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Arkhipov, A.N. [Chernobyl Scientific and Technical Center for International Research (Ukraine); Tkachenko, Yu. [The State Enterprise Regional Monitoring and Domestic Control (RADEC) (Unknown)

    2001-03-01

    Subject-3 has been focused on the migration behavior of long-lived radionuclides in the terrestrial surface environment, especially in connection with their chemical and physical forms. Migration behavior of radionuclides is strongly affected with their chemical and physical forms (for example; Gunten and Benes 1995). One of the two categories in Subject-3 consists of migration from surface soils including aging effects of hot particles, plant uptake from contaminated soils, and resuspension of radionuclides. The other is run off by river system, considering the role of organic materials. (author)

  8. A review of the role of colloids in the release and transport of radionuclides in the near and far field. Pt. 2

    International Nuclear Information System (INIS)

    Tipping, E.; Higgo, J.J.W.

    1992-01-01

    The role of colloids in the release/transport of radionuclides covers a range of scientific disciplines and there is a need for a comprehensive review that pulls together all the relevant research. A literature review has, therefore, been carried out and a bibliography prepared. Entries are in alphabetical (first author) order and abstracts are provided. This is part 2 of a three-part review. Part 1 reviews fundamental theory and DOE and NIREX funded work while Part 3 compares DOE and NIREX-funded work with the other published work and identifies gaps in the DOE and NIREX programmes. (Author)

  9. Radionuclide Air Emissions Report for the Hanford Site Calendar year 1998

    Energy Technology Data Exchange (ETDEWEB)

    DIEDIKER, L.P.

    1999-06-15

    This report documents radionuclide air emissions from the Hanford Site in I998 and the resulting effective dose equivalent to the maximally exposed individual (MEI) member of the public. The report has been prepared in accordance with the Code of Federal Regulations, Title 40, Protection of the Environment, Part 61, National Emission Standards for Hazardous Air Pollutants (40 CFR SI), Subpart H, ''National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities,'' and with the Washington Administrative Code Chapter 246-247, Radiation Protection--Air Emissions. The federal regulations in 40 CFR 61, Subpart H; require the measurement and reporting of radionuclides emitted from Department of Energy facilities and the resulting offsite dose from those emissions. A standard of 10 mrem/yr effective dose equivalent (EDE) is imposed on them. The EDE to the MEI due to routine emissions in 1998 from Hanford Site point sources was 1.3 E-02 mrem (1.3 E-04 mSv), which is 0.13 percent of the federal standard. Chapter 246-247 of the Washington Administrative Code (WAC) requires the reporting of radionuclide emissions from all Department of Energy Hanford Site sources. The state has adopted into these regulations the 40 CFR 61 standard of 10 mrem/yr EDE. The EDE to the MEI attributable to diffuse and fugitive radionuclide air emissions from the Hanford Site in 1998 was 2.5 E-02 mrem (2.5 E-04 mSv). This dose added to the dose from point sources gives a total for all sources of 3.8 E-02 mrem/yr (3.8 E-04 mSv) EDE, which is 0.38 percent of the 10 mrem/yr standard. An unplanned release on August 26, 1998, in the 300 Area of the Hanford Site resulted in a potential dose of 4.1 E-02 mrem to a hypothetical individual at the nearest point of public access to that area. This hypothetical individual was not the MEI since the wind direction on the day of the release was away from the MEI residence. The potential dose from

  10. Screening Risk Assessment for Possible Radionuclides in the Amchitka Marine Environment

    Energy Technology Data Exchange (ETDEWEB)

    NNSA/NV

    2002-10-31

    As part of its environmental stewardship program the U.S. Department of Energy (DOE) is reevaluating three sites where underground nuclear tests were conducted in the deep subsurface of Amchitka Island, Alaska. The tests (i.e., Long Shot, Milrow, and Cannikin) were conducted in 1965, 1969, and 1971, respectively. Extensive investigations were conducted on these tests and their effect on the environment. Evaluations at the time of testing indicated limited release of radionuclides and absence of risk related to the testing; however, these are being reevaluated under the current DOE environmental stewardship program. A screening risk assessment of potential radionuclide release into the marine environment is an important part of this reevaluation. The risk assessment is one of three interrelated activities: a groundwater model and this screening risk assessment, both of which guide the decisions in the third activity, the site closure plan. Thus, the overall objective of the work is to understand, and subsequently manage, any risk to humans and the environment through a closure and long-term stewardship plan. The objective of this screening risk assessment is to predict whether possible releases of radionuclides at the ocean floor would represent potential risks to Native Alaskans by consumption of marine subsistence species. In addition, risks were predicted for consumers of commercial catches of marine organisms. These risks were calculated beginning with estimates of possible radionuclide release at the seafloor (from a groundwater modeling study), into the seawater, through possible uptake by marine organisms, and finally possible consumption by humans. The risk assessment model has 11 elements, progressing from potential release at the seafloor through water and food chains to human intake. Data for each of these elements were systematically found and synthesized from many sources, and represent the best available knowledge. Whenever precise data were lacking

  11. Release of the radioactive patient following radiation therapy

    International Nuclear Information System (INIS)

    Powers, J.; Cancer Board, A.

    2004-01-01

    Patients walk out of medical facilities containing as much as a complete therapeutic dose of radiation on a daily basis. This presents a significant challenge to the radiation protection community, as most patients have no prior education related to radiation and may not have the aptitude to assimilate such knowledge. In the case of targeted radiation therapy in which radionuclides are used to selectively target the cancer, patients are typically released only after adequate elimination and decay of the radionuclide administered. Established modalities of targeted radiotherapy include the use of iodine for thyroid cancer, strontium for bone pain, phosphorous for haematological diseases, 131I-mIBG for neuroblastoma, and most recently Y-90 labelled monoclonal antibodies for lymphoma. In the case of permanent implants, implants of encapsulated radioactive sources are left permanently in the tissues, thus patients are released containing their complete therapeutic dose. Isotopes used in permanent implants include I-125, Pd-103 and Au-198. Radiation safety considerations for both cases, the release of a patient who has received targeted radiotherapy, and the release of a patient who has received a permanent implant, will be discussed. A summary of applicable regulations will serve as a starting point for each of the following considerations; i) Security and source control ii) Instructions to patient and family members iii) Risk to the public As the incidence of cancer increases, and the popularity of targeted radiotherapy and permanent seed implants grows, the event of having an untrained person in possession of a therapeutic dose of radiation becomes more and more common. It is essential to stop and examine the risk of this practice, whether current strategies to reduce the risk to an acceptable level are indeed effective, and whether control over these sources is even feasible. (Author)

  12. Release of the radioactive patient following radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Powers, J.; Cancer Board, A.

    2004-07-01

    Patients walk out of medical facilities containing as much as a complete therapeutic dose of radiation on a daily basis. This presents a significant challenge to the radiation protection community, as most patients have no prior education related to radiation and may not have the aptitude to assimilate such knowledge. In the case of targeted radiation therapy in which radionuclides are used to selectively target the cancer, patients are typically released only after adequate elimination and decay of the radionuclide administered. Established modalities of targeted radiotherapy include the use of iodine for thyroid cancer, strontium for bone pain, phosphorous for haematological diseases, 131I-mIBG for neuroblastoma, and most recently Y-90 labelled monoclonal antibodies for lymphoma. In the case of permanent implants, implants of encapsulated radioactive sources are left permanently in the tissues, thus patients are released containing their complete therapeutic dose. Isotopes used in permanent implants include I-125, Pd-103 and Au-198. Radiation safety considerations for both cases, the release of a patient who has received targeted radiotherapy, and the release of a patient who has received a permanent implant, will be discussed. A summary of applicable regulations will serve as a starting point for each of the following considerations; i) Security and source control ii) Instructions to patient and family members iii) Risk to the public As the incidence of cancer increases, and the popularity of targeted radiotherapy and permanent seed implants grows, the event of having an untrained person in possession of a therapeutic dose of radiation becomes more and more common. It is essential to stop and examine the risk of this practice, whether current strategies to reduce the risk to an acceptable level are indeed effective, and whether control over these sources is even feasible. (Author)

  13. Effects of bedrock fractures on radionuclide transport near a vertical deposition hole for spent nuclear fuel

    International Nuclear Information System (INIS)

    Pulkkanen, V.-M.; Nordman, H.

    2011-12-01

    Effects of bedrock fractures on radionuclide transport near a vertical deposition hole for spent nuclear fuel are studied computationally. The studied fractures are both natural and excavation damage fractures. The emphasis is on the detailed modelling of geometry in 3D in contrast to the traditional radionuclide transport studies that often concentrate on chain decays, sorption, and precipitation at the expense of the geometry. The built computer model is used to assess the significance of components near a deposition hole for radionuclide transport and to estimate the quality of previously used modelling techniques. The results show nearly exponential decrease of radionuclide mass in the bentonite buffer when the release route is a thin natural fracture. The results also imply that size is the most important property of the tunnel section for radionuclide transport. In addition, the results demonstrate that the boundary layer theory can be used to approximate the release of radionuclides with certain accuracy and that a thin fracture in rock can be modelled, at least to a certain limit, by using a fracture with wider aperture but with same flow rate as the thin fracture. (orig.)

  14. Controlled release studies of calcium alginate hydrogels

    International Nuclear Information System (INIS)

    Rendevski, S.; Andonovski, A.; Mahmudi, N.

    2012-01-01

    Controlled release of substances in many cases may be achieved from calcium alginate hydrogels. In this research, the time dependence of the mass of released model substance bovine serum albumin (BSA) from calcium alginate spherical hydrogels of three different types (G/M ratio) have been investigated. The hydrogels were prepared with the drop-wise method of sodium alginate aqueous solutions with concentration of 0.02 g/cm 3 with 0.01 g/cm 3 BSA and a gelling water bath of chitosan in 0.2 M CH 3 COOH/0.4 M CH 3 COONa with added 0.2 M CaCl 2 .The hydrogel structures were characterized by dynamic light scattering and scanning electron microscopy. The controlled release studies were conducted by UV-Vis spectrophotometry of the released medium with p H=7 at 37 °C. The results showed that the model of osmotic pumping is the dominant mechanism of the release. Also, large dependences of the release profile on the homogeneity of the hydrogels were found. (Author)

  15. Behavior of radionuclides in sanitary landfills.

    Science.gov (United States)

    Chang, K C; Chian, E S; Pohland, F G; Cross, W H; Roland, L; Kahn, B

    1984-01-01

    his study was undertaken to evaluate the possibility of disposing low-level radioactive waste in sanitary landfills with leachate containment to prevent environmental releases. To meet this objective, two simulated landfills, each 200 l. in volume and containing 55 kg of municipal refuse, were operated in the laboratory with simulated rainfall additions for a 9-month period to observe the extent to which radio-cobalt, -cesium, -strontium and tritium were leached into the liquid phase. One of the units was operated with leachate recycle, the other as a single pass control. Liquid samples were analyzed weekly for 3H, 58Co, 85Sr and 134Cs tracers. Weekly analyses were also performed for approximately 30 parameters to define the degree of stabilization of the waste. Major parameters included BOD, COD, pH and concentrations of specific organics, metals and gases. Concentrations of stable cobalt, strontium and cesium were also measured periodically. Soluble radioactivity levels in both systems were reduced by factors of 50 for 58Co, 5 for 85Sr and 7 for 134Cs, taking radioactive decay and dilution into account. Some radionuclide removal from the liquid phase was associated with major chemical changes in the landfills that occurred within 80 days for the control system and within 130 days for the recycle unit. Observed acid, sulfide, and CO2 concentrations suggested mechanisms for removing some of the radionuclides from leachate. Detection of 3H in the off-gas indicated that less than 1% of tritiated waste became airborne. The waste in the leachate recycle unit was more completely stabilized than in the control unit.

  16. The sources and fate of radionuclides emitted to the atmosphere

    International Nuclear Information System (INIS)

    Sandalls, J.

    2001-01-01

    The thesis represents an account of the sources and fate of radionuclides entering the atmosphere, and indicates where the candidate, through his own work, has contributed to the overall picture. The sources of the natural and man-made radionuclides found in the atmosphere are identified. New data on emissions from UK coal-fired power stations and UK steel works are reported. Radionuclides produced in nuclear fission and released to the atmosphere in the detonation of nuclear weapons, in nuclear accidents, and through routine discharges from nuclear sites have added to the atmospheric burden of radioactive materials; both acute and chronic low-level emissions are discussed. The various natural processes which remove radionuclides from the atmosphere are described. Soon after release, many radioactive materials become attached to the atmospheric aerosol, but others undergo gas-phase reactions. Some gases are sufficiently long-lived in the troposphere as to find their way into the stratosphere where their fate may be determined by the short-wave radiation from the sun. The nature of the particles of fuel emitted to the atmosphere in the explosion and fire at the Chernobyl nuclear power plant in 1986 are discussed, together with the associated environmental problems. The ground is the major sink for radionuclides leaving the atmosphere, and the behaviour of the more radiologically important radionuclides following deposition is described with special reference to: (i) fallout in both the urban and living environments; (ii) the pathways which may lead to contamination of the food chain; (iii) how the fuel particle fallout from Chernobyl was unique in nuclear accidents; (iv) soil-to-plant transfer of radioelements and (v) how radiation exposure of man can be mitigated in both the contaminated urban and rural environments. (author)

  17. Numerical modelling and parametric study of the atmospheric dispersion after radionuclide releases: the Chernobyl accident and the Algeciras incident. Comparison with observation data

    International Nuclear Information System (INIS)

    Minier, Y.; Mathieu, A.; Quelo, D.; Sportisse, B.; Isnard, O.; Krysta, M.; Bocquet, M.

    2006-01-01

    Full text: The attempts of modelling the release following upon the Chernobyl accident and the Algeciras incident are reported. Computing power and observation database are used for sensitivity and parametric studies. The meteorological mesoscale model MM5 is nudged with the ERA-40 reanalysis to simulate the meteorological conditions used by the dispersion model, POLAIR3D. In case of the Chernobyl accident the points of interest are many: the representativity of the meteorological simulations is evaluated using observations with a special focus on precipitation events. The radionuclide dispersion, the dry deposition and scavenging simulated by POLAIR3D are compared with European measurements of activities and depositions. Results of the sensitivity studies are done to evaluate the impact of the deposition parameterizations and source-term characteristics (height of release, quantities). The time dynamic of the contaminated cloud is also investigated with regard to the arrival time on different countries. Similarly, for the Algeciras release, sensitivity to the meteorological fields, source term and depletion processes are analyzed. For the available activity concentrations in the air, data-model comparisons are performed. (author)

  18. Natural analogue approach for estimating the health risks from release and migration of radionuclides from radioactive waste

    International Nuclear Information System (INIS)

    Gilbert, T.L.

    1983-01-01

    The health risks from radioactive waste may be expressed as a sum of products of transfer factors that characterize the causal chain of events between disposal of radionuclides in a waste field and the consequent health effects. Model estimates for the transfer factors are commonly obtained by modeling transport and other mechanisms in the subsystems that form the links in the causal chain. Natural estimates of some conversion factors for naturally occurring radionuclides can be obtained from data on the concentrations of naturally occurring radionuclides in soil, food, and the human body. These model and natural estimates can be used with scaling procedures to estimate the uncertainties and to obtain better estimates of the values. The scaling procedures take into account the differences in the source characteristics for radionuclides in a waste field of limited size and for radionuclides generally distributed in the natural environment. The ratios of the natural estimates to the model estimates for several transfer factors and several radionuclides belonging to the U-238 decay series have been determined. These ratios range from 1/8 to 4/1 for food-concentration/source-concentration transfer factors for the food pathways and from 1 to 77 for dose-rate/source-concentration transfer factors for the internal radiation dose pathways to various organs. 14 references

  19. Birth control - slow release methods

    Science.gov (United States)

    Contraception - slow-release hormonal methods; Progestin implants; Progestin injections; Skin patch; Vaginal ring ... might want to consider a different birth control method. SKIN PATCH The skin patch is placed on ...

  20. ARRRG/FOOD, Doses from Radioactive Release to Food Chain

    International Nuclear Information System (INIS)

    Napier, B.A.; Roswell, R.L.; Kennedy, W.E. Jr.; Strenge, D.L.

    1984-01-01

    1 - Description of problem or function: ARRRG calculates radiation doses to humans for radionuclides released to bodies of water from which people might obtain fish, other aquatic foods, or drinking water, and in which they might fish, swim, or boat. FOOD calculates radiation doses to humans from deposition on farm or garden soil and crops during either an atmospheric or water release of radionuclides. Deposition may be either directly from the air or from irrigation water. With both programs, doses may be calculated for either a maximum- exposed individual or for a population group. Doses calculated are a one-year dose and a committed dose from one year of exposure. The exposure is usually considered as chronic; however, equations are included to calculate dose and dose commitment from acute, one-time, exposure. 2 - Method of solution: The radiation doses from external exposure to contaminated farm fields or shorelines are calculated assuming an 'infinite' flat plane source of radionuclides. A factor of two is included for surface roughness, and a modifying factor is used to compensate for finite extent in the shoreline calculations. The radionuclide concentrations in aquatic and irrigated food products are based on the radionuclide concentration in the contaminated water, which is based on the release rate of radioactive contamination and the characteristics of the receiving water body. Concentration of radionuclides in plants depends on the concentrations in the soil, air, and water. Concentration of radionuclides in farm animal products, such as milk, meat, or eggs, depends on the animal's consumption of feed, forage, and water containing radionuclides. For persons swimming in contaminated water, the dose is calculated assuming that the body of water is an infinite medium relative to the range of emitted radiations. Persons boating on the water are assumed to be exposed to a dose rate half that of swimmers. Internal doses are calculated as a function of

  1. Study of test methods for radionuclide migration in aerated zone

    International Nuclear Information System (INIS)

    Li Shushen; Guo Zede; Wang Zhiming

    1993-01-01

    Aerated zone is an important natural barrier against transport of radionuclides released from disposal facilities of LLRW. This paper introduces study methods for radionuclide migration in aerated zone, including determination of water movement, laboratory simulation test, and field tracing test. For one purpose, results obtained with different methods are compared. These methods have been used in a five-year cooperative research project between CIRP and JAERI for an establishment of methodology for safety assessment on shallow land disposal of LLRW

  2. Controlled release of tocopherols from polymer blend films

    Science.gov (United States)

    Obinata, Noe

    Controlled release packaging has great potential to increase storage stability of foods by releasing active compounds into foods continuously over time. However, a major limitation in development of this technology is the inability to control the release and provide rates useful for long term storage of foods. Better understanding of the factors affecting active compound release is needed to overcome this limitation. The objective of this research was to investigate the relationship between polymer composition, polymer processing method, polymer morphology, and release properties of active compounds, and to provide proof of principle that compound release is controlled by film morphology. A natural antioxidant, tocopherol was used as a model active compound because it is natural, effective, heat stable, and soluble in most packaging polymers. Polymer blend films were produced from combination of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) with 3000 ppm mixed tocopherols using conventional blending method and innovative blending method, smart blending with a novel mixer using chaotic advection. Film morphologies were visualized with scanning electron microscopy (SEM). Release of tocopherols into 95% ethanol as a food simulant was measured by UV/Visible spectrophotometry or HPLC, and diffusivity of tocopherols in the polymers was estimated from this data. Polymer composition (blend proportions) and processing methods have major effects on film morphology. Four different types of morphologies, dispersed, co-continuous, fiber, and multilayer structures were developed by either conventional extrusion or smart blending. With smart blending of fixed polymer compositions, different morphologies were progressively developed with fixed polymer composition as the number of rod rotations increased, providing a way to separate effects of polymer composition and morphology. The different morphologies

  3. Tracking the complete revolution of surface westerlies over Northern Hemisphere using radionuclides emitted from Fukushima

    International Nuclear Information System (INIS)

    Hernández-Ceballos, M.A.; Hong, G.H.; Lozano, R.L.; Kim, Y.I.; Lee, H.M.; Kim, S.H.; Yeh, S.-W.; Bolívar, J.P.; Baskaran, M.

    2012-01-01

    Massive amounts of anthropogenic radionuclides were released from the nuclear reactors located in Fukushima (northeastern Japan) between 12 and 16 March 2011 following the earthquake and tsunami. Ground level air radioactivity was monitored around the globe immediately after the Fukushima accident. This global effort provided a unique opportunity to trace the surface air mass movement at different sites in the Northern Hemisphere. Based on surface air radioactivity measurements around the globe and the air mass backward trajectory analysis of the Fukushima radioactive plume at various places in the Northern Hemisphere by employing the Hybrid Single-Particle Lagrangian Integrated Trajectory model, we show for the first time, that the uninterrupted complete revolution of the mid-latitude Surface Westerlies took place in less than 21 days, with an average zonal velocity of > 60 km/h. The position and circulation time scale of Surface Westerlies are of wide interest to a large number of global researchers including meteorologists, atmospheric researchers and global climate modellers. -- Highlights: ► Evidence of the South Korea contamination with released radiocesium from Fukushima. ► Field samples and air mass analysis were utilized to elucidate the transport of those radionuclides. ► Characterization of the air mass movements at different sites at the Earth's surface. ► Verification of the uninterrupted complete revolution of the artificial radionuclides released in Fukushima. ► Quantification of the velocity of the artificial radionuclides released in Fukushima.

  4. Tracking the complete revolution of surface westerlies over Northern Hemisphere using radionuclides emitted from Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Ceballos, M.A. [Department of Applied Physics, University of Huelva, Huelva (Spain); Hong, G.H. [Korea Ocean Research and Development Institute, Ansan 426-744 (Korea, Republic of); Lozano, R.L. [Department of Applied Physics, University of Huelva, Huelva (Spain); Kim, Y.I. [Korea Ocean Research and Development Institute, Uljin 767-813 (Korea, Republic of); Lee, H.M.; Kim, S.H. [Korea Ocean Research and Development Institute, Ansan 426-744 (Korea, Republic of); Yeh, S.-W. [Department of Environmental Marine Science, Hanyang University, Ansan, 426-791 (Korea, Republic of); Bolivar, J.P., E-mail: bolivar@uhu.es [Department of Applied Physics, University of Huelva, Huelva (Spain); Baskaran, M. [Department of Geology, Wayne State University, Detroit, Michigan (United States)

    2012-11-01

    Massive amounts of anthropogenic radionuclides were released from the nuclear reactors located in Fukushima (northeastern Japan) between 12 and 16 March 2011 following the earthquake and tsunami. Ground level air radioactivity was monitored around the globe immediately after the Fukushima accident. This global effort provided a unique opportunity to trace the surface air mass movement at different sites in the Northern Hemisphere. Based on surface air radioactivity measurements around the globe and the air mass backward trajectory analysis of the Fukushima radioactive plume at various places in the Northern Hemisphere by employing the Hybrid Single-Particle Lagrangian Integrated Trajectory model, we show for the first time, that the uninterrupted complete revolution of the mid-latitude Surface Westerlies took place in less than 21 days, with an average zonal velocity of > 60 km/h. The position and circulation time scale of Surface Westerlies are of wide interest to a large number of global researchers including meteorologists, atmospheric researchers and global climate modellers. -- Highlights: Black-Right-Pointing-Pointer Evidence of the South Korea contamination with released radiocesium from Fukushima. Black-Right-Pointing-Pointer Field samples and air mass analysis were utilized to elucidate the transport of those radionuclides. Black-Right-Pointing-Pointer Characterization of the air mass movements at different sites at the Earth's surface. Black-Right-Pointing-Pointer Verification of the uninterrupted complete revolution of the artificial radionuclides released in Fukushima. Black-Right-Pointing-Pointer Quantification of the velocity of the artificial radionuclides released in Fukushima.

  5. Static and mobile networks design for atmospheric accidental releases monitoring

    International Nuclear Information System (INIS)

    Abida, R.

    2010-01-01

    The global context of my PhD thesis work is the optimization of air pollution monitoring networks, but more specifically it concerns the monitoring of accidental releases of radionuclides in air. The optimization problem of air quality measuring networks has been addresses in the literature. However, it has not been addresses in the context of surveillance of accidental atmospheric releases. The first part of my thesis addresses the optimization of a permanent network of monitoring of radioactive aerosols in the air, covering France. The second part concerns the problem of targeting of observations in case of an accidental release of radionuclides from a nuclear plant. (author)

  6. Review of radionuclide source terms used for performance-assessment analyses

    International Nuclear Information System (INIS)

    Barnard, R.W.

    1993-06-01

    Two aspects of the radionuclide source terms used for total-system performance assessment (TSPA) analyses have been reviewed. First, a detailed radionuclide inventory (i.e., one in which the reactor type, decay, and burnup are specified) is compared with the standard source-term inventory used in prior analyses. The latter assumes a fixed ratio of pressurized-water reactor (PWR) to boiling-water reactor (BWR) spent fuel, at specific amounts of burnup and at 10-year decay. TSPA analyses have been used to compare the simplified source term with the detailed one. The TSPA-91 analyses did not show a significant difference between the source terms. Second, the radionuclides used in source terms for TSPA aqueous-transport analyses have been reviewed to select ones that are representative of the entire inventory. It is recommended that two actinide decay chains be included (the 4n+2 ''uranium'' and 4n+3 ''actinium'' decay series), since these include several radionuclides that have potentially important release and dose characteristics. In addition, several fission products are recommended for the same reason. The choice of radionuclides should be influenced by other parameter assumptions, such as the solubility and retardation of the radionuclides

  7. Model-based computer-aided design for controlled release of pesticides

    DEFF Research Database (Denmark)

    Muro Sunè, Nuria; Gani, Rafiqul; Bell, G.

    2005-01-01

    In the field of controlled release technology for pesticides or active ingredients (AI), models that can predict its delivery during application are important for purposes of design and marketing of the pesticide product. Appropriate models for the controlled release of pesticides, if available, ...... extended models have been developed and implemented into a computer-aided system. The total model consisting of the property models embedded into the release models are then employed to study the release of different combinations of AIs and polymer-based microcapsules.......In the field of controlled release technology for pesticides or active ingredients (AI), models that can predict its delivery during application are important for purposes of design and marketing of the pesticide product. Appropriate models for the controlled release of pesticides, if available...

  8. On release of radionuclides from a near-surface radioactive waste repository to the environment

    Directory of Open Access Journals (Sweden)

    Gudelis Arūnas

    2015-09-01

    Full Text Available A closed near-surface radioactive waste repository is the source of various radionuclides causing the human exposure. Recent investigations confirm an effectiveness of the engineering barriers installed in 2006 to prevent the penetration of radionuclides to the environment. The tritium activity concentration in groundwater decreased from tens of kBq/l to below hundreds of Bq/l. The monitoring and groundwater level data suggest the leaching of tritium from previously contaminated layers of unsaturated zone by rising groundwater while 210Pb may disperse as a decay product of 226Ra daughters.

  9. A review of the persistence of long-lived radionuclides in the marine environment - sediment/water interactions

    International Nuclear Information System (INIS)

    Edgington, D.N.

    1981-01-01

    There is a considerable international concern regarding the advisability and safety of the disposal or dumping of radioactive wastes in the oceans. The assimilation capacity of the ocean for long-lived radionuclides will depend largely on the maximum concentrations that can be safely or agreeably contained within it. Since the mechanisms for removal or control are radioactive decay or association with particles and burial in the sediments, an understanding of the processes involved, in sediment-particle/water interactions, at the sediment/water interface, and within the sediment is extremely important. During the last 35 years there have been considerable inputs of long-lived radionuclides into the oceans as a result of weapons testing, routine releases from fuels reprocessing plants and operating nuclear reactors, and accidental releases from a variety of sources; this provides an excellent opportunity to study their behaviour in the oceans. Thus, the purpose here is to synthesize the present state of our knowledge of sediment/water interactions from studies, mainly of plutonium and americium, conducted in a wide range of environments from the Arctic to the tropics. (author)

  10. Radioactive release during nuclear accidents in Chernobyl and Fukushima

    Science.gov (United States)

    Nur Ain Sulaiman, Siti; Mohamed, Faizal; Rahim, Ahmad Nabil Ab

    2018-01-01

    Nuclear accidents that occurred in Chernobyl and Fukushima have initiated many research interests to understand the cause and mechanism of radioactive release within reactor compound and to the environment. Common types of radionuclide release are the fission products from the irradiated fuel rod itself. In case of nuclear accident, the focus of monitoring will be mostly on the release of noble gases, I-131 and Cs-137. As these are the only accidents have been rated within International Nuclear Events Scale (INES) Level 7, the radioactive release to the environment was one of the critical insights to be monitored. It was estimated that the release of radioactive material to the atmosphere due to Fukushima accident was approximately 10% of the Chernobyl accident. By referring to the previous reports using computational code systems to model the release rate, the release activity of I-131 and Cs-137 in Chernobyl was significantly higher compare to Fukushima. The simulation code also showed that Chernobyl had higher release rate of both radionuclides on the day of accident. Other factors affecting the radioactive release for Fukushima and Chernobyl accidents such as the current reactor technology and safety measures are also compared for discussion.

  11. Transport of radionuclides in the atmosphere during complex meteorological conditions

    International Nuclear Information System (INIS)

    Antic, D.; Telenta, B.

    1991-01-01

    Radionuclides from various sources (nuclear and fossil fuel power plants, nuclear facilities, medical facilities, etc.) are being released to the atmosphere. The meteorological conditions determine the atmospheric turbulence, dispersion, and removal processes of the radionuclides. A two-dimensional version of the cloud model based on the Klemp-Wilhelmson dynamic and Lin et al.'s microphysics and thermodynamics has been adapted and used to simulate the transport of radionuclides emitted from a power plant or other source to the atmosphere. Calculations of the trajectories and radii for a few puffs are included in this paper. These numerical investigations show that the presented model can be used for the transport simulation of radionuclides and for the assessment of the radiological impact of power plants and other sources in safety assessments and comparative studies. Because it can simulate puff trajectories, this model is especially valuable in the presence of complex meteorological conditions

  12. Photoresponsive lipid-polymer hybrid nanoparticles for controlled doxorubicin release

    Science.gov (United States)

    Yao, Cuiping; Wu, Ming; Zhang, Cecheng; Lin, Xinyi; Wei, Zuwu; Zheng, Youshi; Zhang, Da; Zhang, Zhenxi; Liu, Xiaolong

    2017-06-01

    Currently, photoresponsive nanomaterials are particularly attractive due to their spatial and temporal controlled drug release abilities. In this work, we report a photoresponsive lipid-polymer hybrid nanoparticle for remote controlled delivery of anticancer drugs. This hybrid nanoparticle comprises three distinct functional components: (i) a poly(D,L-lactide-co-glycolide) (PLGA) core to encapsulate doxorubicin; (ii) a soybean lecithin monolayer at the interface of the core and shell to act as a molecular fence to prevent drug leakage; (iii) a photoresponsive polymeric shell with anti-biofouling properties to enhance nanoparticle stability, which could be detached from the nanoparticle to trigger the drug release via a decrease in the nanoparticle’s stability under light irradiation. In vitro results revealed that this core-shell nanoparticle had excellent light-controlled drug release behavior (76% release with light irradiation versus 10% release without light irradiation). The confocal microscopy and flow cytometry results also further demonstrated the light-controlled drug release behavior inside the cancer cells. Furthermore, a CCK8 assay demonstrated that light irradiation could significantly improve the efficiency of killing cancer cells. Meanwhile, whole-animal fluorescence imaging of a tumor-bearing mouse also confirmed that light irradiation could trigger drug release in vivo. Taken together, our data suggested that a hybrid nanoparticle could be a novel light controlled drug delivery system for cancer therapy.

  13. Derivation of release limits for a typical uranium mining and milling facility

    International Nuclear Information System (INIS)

    1985-09-01

    This report develops guidelines for calculating derived release limits (DRLs) for releases of each radionuclide belonging to the uranium-238 and thorium-232 decay chains to atmosphere, surface water and groundwater from uranium mining and milling operations in Canada. DRLs are defined as calculated limits on releases from the facility that result in radiation exposures through all environmental pathways equal to the annual effective dose equivalent limit of 0.005 Sv for stochastic effects or the annual dose equivalent limit of 0.05 Sv for non-stochastic effects in the critical group. By definition, DRLs apply to controllable radionuclide emissions which occur during the operational phase of mine/mill facilities. The report develops a steady-state environmental transfer model to determine environmental dilution and dispersion in atmosphere, surface water and groundwater between the sources at the mine and mill and the critical group receptor. Exposure pathways incorporated in the model include external exposure from immersion in the airborne plume, immersion in water, contaminated ground and contaminated shoreline sediments. Internal exposure pathways include inhalation of contaminated air and ingestion of contaminated water and terrestrial and aquatic foods

  14. Release of iodine radionuclides from gas media in a system of selective block sorbents

    International Nuclear Information System (INIS)

    Moskvin, L.N.; Miroshnikov, V.S.; Mel'nikov, V.A.; Chetverikov, V.V.

    1979-01-01

    A scheme of extracting iodine radionuclides from gas flows in a system of selective sorbents has been developed. The method provides separation of three forms of iodine: the aerosol component, the elementary iodine and organic-iodine compounds. Aerosols are trapped by a mechanical filter made of porous polytetrafluoroethylene with pores of no more than 1 μm. Silver-based sorbents for the elementary iodine are made by sintering the granular polytetrafluoroethylene (the size of granules is 0.1-0.5 mm) with of finely dispersed solver (5% mass). Organic iodine compounds are extracted by a silica sorbent impregnated with silver nitrate. The efficiency of sorbents was tested in gas flows with a known content of 131 I in the form of elementary iodine and methyl iodide. The results of experiments show that the efficiency of sorption of elementary iodine by a metallic-silver sorbent and of methyl iodide by a SiO 2 /AgNO 3 sorbent constitutes no less than 99% at a flow rate of up to 200 l/h. The iodine has been extracted at a flow rate of 100 l/h during 100 hours and for that time the efficiency of the iodine sorbtion has not changed. The suggested variant of extracting iodine radionuclides from gaseous media can be used both for fast control of iodine content in gas blowoffs and for researches aimed at studying the distribution of iodine forms in steam-and-gas media depending on nuclear plant operating conditions

  15. Critical review: Radionuclide transport, sediment transport, and water quality mathematical modeling; and radionuclide adsorption/desorption mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Y.; Serne, R.J.; Arnold, E.M.; Cowan, C.E.; Thompson, F.L. [Pacific Northwest Lab., Richland, WA (United States)

    1981-01-01

    This report describes the results of a detailed literature review of radionuclide transport models applicable to rivers, estuaries, coastal waters, the Great Lakes, and impoundments. Some representatives sediment transport and water quality models were also reviewed to evaluate if they can be readily adapted to radionuclide transport modeling. The review showed that most available transport models were developed for dissolved radionuclide in rivers. These models include the mechanisms of advection, dispersion, and radionuclide decay. Since the models do not include sediment and radionuclide interactions, they are best suited for simulating short-term radionuclide migration where: (1) radionuclides have small distribution coefficients; (2) sediment concentrations in receiving water bodies are very low. Only 5 of the reviewed models include full sediment and radionuclide interactions: CHMSED developed by Fields; FETRA SERATRA, and TODAM developed by Onishi et al, and a model developed by Shull and Gloyna. The 5 models are applicable to cases where: (1) the distribution coefficient is large; (2) sediment concentrations are high; or (3) long-term migration and accumulation are under consideration. The report also discusses radionuclide absorption/desorption distribution ratios and addresses adsorption/desorption mechanisms and their controlling processes for 25 elements under surface water conditions. These elements are: Am, Sb, C, Ce, Cm, Co, Cr, Cs, Eu, I, Fe, Mn, Np, P, Pu, Pm, Ra, Ru, Sr, Tc, Th, {sup 3}H, U, Zn and Zr.

  16. Factors influencing the transfer of radionuclides in agricultural food chains

    International Nuclear Information System (INIS)

    Vandecasteele, C.M.; Zeevaert, Th.; Kirchmann, R.

    1991-01-01

    The applications of nuclear energy have led and will continue to lead to routine or accidental discharges of radioactive elements into the atmospheric and/or aquatic environment resulting in the exposure of populations to ionising radiations. The radionuclides released into the atmosphere are transported downwind, dispersed by the atmospheric mixing phenomena and progressively settled by deposition processes. During the passage of the radioactive cloud, people are irradiated externally as well as internally by inhalation. After the passage of the cloud, exposure of the population continues via three main pathways: external irradiation from the radionuclides deposited on the ground, inhalation of resuspended contaminated particles and ingestion of contaminated food products. When discharged into aquatic systems, the radionuclides can be partly removed from the aqueous phase by adsorption on suspended solids and bottom sediments. As the radioactivity disperses, there is a continuing exchange between water and solid phases. The contaminated sediments deposited on the banks of rivers, lakes and coastal area lead to external irradiation of people spending time at these sites. The residual activity in water exposes man internally through the ingestion of drinking water and food products, contaminated by irrigation of vegetation and ingestion of water by livestock. Among the various exposure pathways, the main route of entry of fission products and most other artificial radionuclides into man has been identified as uptake from the diet. Since agricultural products constitute the basic diet of most populations, the fate and behavior of radionuclides in agricultural ecosystems are of primary importance when assessing the exposure risk of man from environmental releases of radioactivity. 69 refs., 4 figs

  17. Report of the first research co-ordination meeting on the co-ordinated research programme: Development and selection of analytical techniques for measuring accidentally released radionuclides in environment

    International Nuclear Information System (INIS)

    2001-01-01

    The participants at the second Research Co-ordination Meeting (Vienna, 12-16 August 1991) of the CRP on 'Rapid Instrumental and Separation Methods for Monitoring Radionuclides in Food and Environmental Samples', recommended that a new CRP be established. The current CRP on 'Development and Selection of Analytical Techniques and Procedures for Measuring Accidentally Released Radionuclides in Environment' was established based on this recommendation. The objectives of this CRP are to conduct research and development on applicable methodologies for response to accidental releases, and to improve and maintain the capabilities of the network of laboratories and provide training of individuals within member states. Thus, the CRP serves as a vehicle to maintain contact within the network of laboratories, while developing and transferring analytical techniques and procedures for measuring accidentally released radioactivity. The purpose of the Research Co-ordination Meeting is to discuss the proposed research programs, the status to date and the work planned for the duration of the CRP. The meeting also provides the opportunity for the CRP participants to exchange ideas and possibly develop collaborations in their research. The members of the CRP also need to discuss issues related to the previous CRP on Rapid methods. These include: the preparation of the final report of the previous CRP, the preparation of an addendum to TRS-295 and the ultimate revision or updating of TRS-295. Finally, it is intended that the members of the CRP should discuss the mandate and scope of work of the network of analytical laboratories and the steps needed to firmly establish this network

  18. Optimization of production and quality control of therapeutic radionuclides and radiopharmaceuticals. Final report of a co-ordinated research project 1994-1998

    International Nuclear Information System (INIS)

    1999-09-01

    The 'renaissance' of the therapeutic applications of radiopharmaceuticals during the last few years was in part due to a greater availability of radionuclides with appropriate nuclear decay properties, as well as to the development of carrier molecules with improved characteristics. Although radionuclides such as 32 P, 89 Sr and 131 I, were used from the early days of nuclear medicine in the late 1930s and early 1940s, the inclusion of other particle emitting radionuclides into the nuclear medicine armamentarium was rather late. Only in the early 1980s did the specialized scientific literature start to show the potential for using other beta emitting nuclear reactor produced radionuclides such as 153 Sm, 166 Ho, 165 Dy and 186-188 Re. Bone seeking agents radiolabelled with the above mentioned beta emitting radionuclides demonstrated clear clinical potential in relieving intense bone pain resulting from metastases of the breast, prostate and lung of cancer patients. Therefore, upon the recommendation of a consultants meeting held in Vienna in 1993, the Co-ordinated Research Project (CRP) on Optimization of the Production and quality control of Radiotherapeutic Radionuclides and Radiopharmaceuticals was established in 1994. The CRP aimed at developing and improving existing laboratory protocols for the production of therapeutic radionuclides using existing nuclear research reactors including the corresponding radiolabelling, quality control procedures; and validation in experimental animals. With the participation of ten scientists from IAEA Member States, several laboratory procedures for preparation and quality control were developed, tested and assessed as potential therapeutic radiopharmaceuticals for bone pain palliation. In particular, the CRP optimised the reactor production of 153 Sm and the preparation of the radiopharmaceutical 153 Sm-EDTMP (ethylene diamine tetramethylene phosphonate), as well as radiolabelling techniques and quality control methods for

  19. Radiation exposure by man-modified materials containing natural radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Becker, D.E. [Technical Inspection Agency of Bavaria, Munich (Germany); Eder, E. [Government of Bavaria, Ministry for State Development and Environmental Affairs Development, Munich (Germany); Reichelt, A. [Technical Inspection Agency of Bavaria, Munich (Germany)

    1992-07-01

    More than one hundred materials, containing natural radioactive nuclides, are being investigated due to radiation exposure to people. This paper deals with thoriated gas mantles and shows that the radiation exposure by inhalation of radionuclides released while burning and exchange is not negligible. (author)

  20. Maternal transfer of anthropogenic radionuclides to eggs in a small shark

    International Nuclear Information System (INIS)

    Jeffree, Ross A.; Oberhansli, Francois; Teyssie, Jean-Louis; Fowler, Scott W.

    2015-01-01

    Maternal transfer of radionuclides to progeny is one of the least known sources of contamination in marine biota and more information is needed to assess its radiological significance. A radiotracer study on spotted dogfish, Scyliorhinus canicula, evaluated the hypothesis that four anthropogenic radionuclides (Cobalt-60, Zinc-65, Americium-241 and Cesium-134) could be maternally transferred to eggs and each of their major components during maternal ingestion of radiolabelled food. The linear regressions between cumulative radioactivity that had been maternally ingested and the level in subsequently laid eggs were used to derive maternal-to-egg transfer factors (mTFs). These maternal transfers varied over an order of magnitude and were ranked 134 Cs >  65 Zn >  60 Co >  241 Am. This ranking was the same as their relative assimilation efficiencies in radiolabelled food consumed by adults. Among these four radionuclides the potential radiological exposure of embryos is accentuated for 65 Zn and 134 Cs due to their predominant transfer to egg yolk where they are available for subsequent absorption by the embryo as it develops prior to hatching from the egg capsule. Thus, for cartilaginous fish like shark, the potential radioecological consequences of a pulsed release of these radionuclides into the marine environment may extend beyond the temporal duration of the release. - Highlights: • Dogfish maternally transfer anthropogenic radionuclides to eggs. • Transfers are ranked 134 Cs >  65 Zn >  60 Co >  241 Am. • Both 65 Zn and 60 Co are mainly deposited in yolk

  1. Radionuclide Incorporation and Long Term Performance of Apatite Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianwei [Louisiana State Univ., Baton Rouge, LA (United States); Lian, Jie [Rensselaer Polytechnic Inst., Troy, NY (United States); Gao, Fei [Univ. of Michigan, Ann Arbor, MI (United States)

    2016-01-04

    This project aims to combines state-of-the-art experimental and characterization techniques with atomistic simulations based on density functional theory (DFT) and molecular dynamics (MD) simulations. With an initial focus on long-lived I-129 and other radionuclides such as Cs, Sr in apatite structure, specific research objectives include the atomic scale understanding of: (1) incorporation behavior of the radionuclides and their effects on the crystal chemistry and phase stability; (2) stability and microstructure evolution of designed waste forms under coupled temperature and radiation environments; (3) incorporation and migration energetics of radionuclides and release behaviors as probed by DFT and molecular dynamics (MD) simulations; and (4) chemical durability as measured in dissolution experiments for long term performance evaluation and model validation.

  2. The measurement of released radionuclides during TIG-Welding and Grinding

    International Nuclear Information System (INIS)

    Reichelt, A.; Lehmann, K.-H.; Reineking, A.; Eder, E.

    2000-01-01

    The radiological relevance of the TIG welding using thoriated tungsten electrodes has recently been proved by means of different studies. As a result of this the TUEV Sueddeutschland and the University of Goettingen have carried out special investigations concerning the release of radionuclides during TIG welding. The main emphasis of these investigations were the representativity of various sampling techniques, the influence of various parameters during welding as well as the determination of activity size distributions related to the aerodynamic diameter of the inhaled aerosols. The properties of the tungsten rods are improved through the addition of radioactive thorium. We investigated the radiation exposure by handling with thoriated tungsten welding rods. We investigated the different exposure pathways and determined the specific activity in dependence to the different types of welding rods. By carrying out surveys with the users, we determined the exposure pathways for the individual exposed persons: TIG - hand-welders', TIG 'machine-welders', labourers, other persons. We measured the activity concentration of the breathing air while welding, at grinding the electrodes and by staying in the rooms where usually it's welded. The size distribution of the aerosol-attached activity was determined with several kinds of impactors. The main emphasis was the comparison of the different sampling systems at the measuring of the activity concentration of the breathing air. Selective sampling by impactors: · Berner-impactor, stationary · Sierra-impactor, stationary · Anderson-Imcaktor, stationary · Marple-impactor, personal sampler Aerosol sampling by air samplers · 5 personal air sampler · 2 stationary sampler, ring face · 2 stationary sampler, open face Rn-220-Measurements · Thoron-monitor Determination of activities on measuring filters · alpha spectrometry · low-level-gamma-spectrometry. For the various exposed persons, at the extern irradiation with gamma

  3. Accumulation and potential dissolution of Chernobyl-derived radionuclides in river bottom sediment

    International Nuclear Information System (INIS)

    Sanada, Yukihisa; Matsunaga, Takeshi; Yanase, Nobuyuki; Nagao, Seiya; Amano, Hikaru; Takada, Hideshige; Tkachenko, Yuri

    2002-01-01

    Areas contaminated with radionuclides from the Chernobyl nuclear accident have been identified in Pripyat River near the Chernobyl Nuclear Power Plant. The river bottom sediment cores contained 137 Cs (10 5 - 10 6 Bq/m 2 ) within 0-30 cm depth, whose concentration is comparable to that in the ground soil in the vicinity of the nuclear power plant (the Exclusion Zone). The sediment cores also accumulated 90 Sr (10 5 Bq/m 2 ), 239,240 Pu (10 4 Bq/m 2 ) and 241 Am (10 4 Bq/m 2 ) derived from the accident. Several nuclear fuel particles have been preserved at 20-25 cm depth that is the peak area of the concentrations of the radionuclides. Th ese inventories in the bottom sediments were compared with those of the released radionuclides during the accident. An analysis using a selective sequential extraction technique was applied for the radionuclides in the sediments. Results suggest that the possibility of release of 137 Cs and 239,240 Pu from the bottom sediment was low compared with 90 Sr. The potential dissolution and subsequent transport of 90 Sr from the river bottom sediment should be taken into account with respect to the long-term radiological influence on the aquatic environment

  4. Direct investigations of the immobilization of radionuclides in the alteration phases of spent nuclear fuel. 1998 annual progress report

    International Nuclear Information System (INIS)

    Burns, P.C.; Finch, R.J.

    1998-01-01

    'In an oxidizing environment, such as in the proposed repository at Yucca Mountain, rapid alteration rates are expected for spent nuclear fuel. Lab.-scale simulations have repeatedly shown that the dominant alteration products under repository conditions will be uranyl phases. There is an inadequate database that relates to the effects of the alteration products on the release of radionuclides, but this information is essential to provide a radionuclide release estimate. It is likely that many of the radionuclides contained in the fuel will be incorporated into the alteration products that form, potentially with a profound impact on the future mobility of radionuclides in the repository. The authors objective is to characterize the incorporation of radionuclides into alteration products by synthesis of uranyl phases doped with radionuclides, appropriate surrogate elements, or non-radioactive isotopes, followed by detailed phase characterization by diffraction and spectroscopic techniques. The research will permit a more realistic estimate of the release rates of the radionuclides from the near-field environment. This report summarizes work after 8 months of a 3-year project. The objective of investigating radionuclide incorporation in uranyl phases has required the development of synthesis techniques for various uranyl phases that are expected to form under repository conditions. The authors have synthesized and determined the structures of several uranyl phases that are new to science and that may be important alteration products under repository conditions. They have also undertaken the determination and refinement of the crystal structures of various uranyl phases that are likely to form under repository conditions. Other experiments include the investigation of the ion-exchange properties of uranyl phases under repository conditions.'

  5. Role of solubles and particulates in radionuclide accumulation in the oyster Crassostrea Gigas in the discharge canal of a nuclear power plant

    International Nuclear Information System (INIS)

    Harrison, F.L.; Wong, K.M.; Heft, R.E.

    1972-01-01

    Changes in 54 Mn, 60 Co, 65 Zn, and 137 Cs concentrations were followed in oysters introduced into a discharge canal receiving low-level radioactive waste from a boiling water reactor. Groups of animals were maintained either in filtered or nonfiltered discharge-canal water. They were sampled immediately before and after single radioactive releases and at one-day intervals thereafter. Radionuclide concentrations were determined also in the water and in suspended and settled particulates. In the canal water, concentrations changed rapidly during a release, reaching peak values within 30 minutes. The partition between soluble and particulate (filterable) phases in the water differed with the radionuclide. Continuous sampling of suspended particulates after single releases showed considerable variation in concentrations per liter of water for each radionuclide. Comparisons of animals held in filtered water to those in nonfiltered water showed similar concentrations only for 137 Cs. Results indicate that suspended particulates play an important role in the accumulation of some radionuclides and that resuspension of particulates is an important source between periods of releases. (U.S.)

  6. Behaviour of uranium series radionuclides in surface water (Crouzille, Limousin). Geochemical implications

    International Nuclear Information System (INIS)

    Moulin, J.

    2008-06-01

    Understanding natural radionuclides behaviour in surface water is a required step to achieve uranium mine rehabilitation and preserve water quality. The first objective of this thesis is to determine which are the radionuclides sources in a drinking water reservoir. The second objective is to improve the knowledge about the behaviour of uranium series radionuclides, especially actinium. The investigated site is a brook (Sagnes, Limousin, France) which floods a peat bog contaminated by a former uranium mine and which empties into the Crouzille lake. It allows studying radionuclides transport in surface water and radionuclides retention through organic substance or water reservoir. Radionuclides distribution in particulate, colloidal and dissolved phases is determined thanks to ultra-filtrations. Gamma spectrometry allows measuring almost all natural radionuclides with only two counting stages. However, low activities of 235 U series radionuclides impose the use of very low background well-type Ge detectors, such as those of the Underground Laboratory of Modane (France). Firstly, this study shows that no or few radionuclides are released by the Sagnes peat bog, although its radioactivity is important. Secondly, it provides details on the behaviour of uranium series radionuclides in surface water. More specifically, it provides the first indications of actinium solubility in surface water. Actinium's behaviour is very close to uranium's even if it is a little less soluble. (author)

  7. A Korean radioecology model to simulate radionuclide behavior in agricultural ecosystems following a nuclear emergency and its application to countermeasures

    International Nuclear Information System (INIS)

    Hwang, W.T.; Suh, K.S.; Kim, E.H.; Han, M.H.; Lee, H.S.; Lee, C.W.

    2003-01-01

    A Korean radioecology model to simulate radionuclide behavior in agricultural ecosystems has been developed as a module for evaluating the ingestion dose in a Korean real-time dose assessment system FADAS, which evaluates the comprehensive radiological consequences in an accidental release of radionuclides to the environment. Using the predictive results of a Korean radioecology model, a methodology for the optimization of countermeasures has been designed based on a cost-benefit analysis. In this manuscript, a Korean radioecology model including agricultural countermeasures was introduced, and discussed with the sample calculations for the postulated accidental release of radionuclides to the environment. (author)

  8. Monitoring of Radionuclide Contamination in Food Samples in Malaysia due to Daiichi Reactor Accident in Fukushima, Japan

    International Nuclear Information System (INIS)

    Nurrul Assyikeen Mohd Jaffary; Wo, Y.M.; Abdul Kadir Ishak

    2015-01-01

    On March 11, 2011, a serious accident occurred in Daiichi nuclear reactor plant, Fukushima, Japan which caused radioactive materials been released into the atmosphere in the form of aerosols and dust particles. Sea water around the plant was also found contaminated with high radioactivity readings. These radioactive materials could be transported by the winds and ocean current across international borders and cannot be controlled by human. Thus, a continuous monitoring activity of radionuclide content in the air and sea water needs to be conducted by the authorities. In addition to radioactivity monitoring, Malaysia should also control the entry of contaminated food in order to prevent radionuclide ingestion by human. The radionuclide 131 I, 134 Cs and 137 Cs were used as a measure of pollution levels and counted with gamma spectrometry using standard analysis method suggested by AOAC International. In this paper, details description of the role of Radiochemical and Environment Group, Nuclear Malaysia who is responsible in analyzing the radioactivity in the food samples due to Fukushima Daiichi, Japan accident was included. The radioactivity limit adopted and analysis results from this monitoring were discussed. (author)

  9. Methodology of external exposure calculation for reuse of conditional released materials from decommissioning - 59138

    International Nuclear Information System (INIS)

    Ondra, Frantisek; Vasko, Marek; Necas, Vladimir

    2012-01-01

    The article presents methodology of external exposure calculation for reuse of conditional released materials from decommissioning using VISIPLAN 3D ALARA planning tool. Production of rails has been used as an example application of proposed methodology within the CONRELMAT project. The article presents a methodology for determination of radiological, material, organizational and other conditions for conditionally released materials reuse to ensure that workers and public exposure does not breach the exposure limits during scenario's life cycle (preparation, construction and operation of scenario). The methodology comprises a proposal of following conditions in the view of workers and public exposure: - radionuclide limit concentration of conditionally released materials for specific scenarios and nuclide vectors, - specific deployment of conditionally released materials eventually shielding materials, workers and public during the scenario's life cycle, - organizational measures concerning time of workers or public stay in the vicinity on conditionally released materials for individual performed scenarios and nuclide vectors. The above mentioned steps of proposed methodology have been applied within the CONRELMAT project. Exposure evaluation of workers for rail production is introduced in the article as an example of this application. Exposure calculation using VISIPLAN 3D ALARA planning tool was done within several models. The most exposed profession for scenario was identified. On the basis of this result, an increase of radionuclide concentration in conditional released material was proposed more than two times to 681 Bq/kg without no additional safety or organizational measures being applied. After application of proposed safety and organizational measures (additional shielding, geometry changes and limitation of work duration) it is possible to increase concentration of radionuclide in conditional released material more than ten times to 3092 Bq/kg. Storage

  10. Criteria of reference radionuclides for safety analysis of spent fuel waste disposal

    International Nuclear Information System (INIS)

    Suryanto

    1998-01-01

    Study on the criteria for reference radionuclides selection for assessment on spent fuel disposal have done. The reference radionuclides in this study means radionuclides are predicted to contribute of the most radiological effect for man if spent fuel waste are discharged on deep geology formation. The research was done by investigate critically of parameters were used on evaluation a kind of radionuclide. Especially, this research study of parameter which relevant disposal case and or spent fuel waste on deep geology formation . The research assumed that spent fuel discharged on deep geology by depth 500-1000 meters from surface of the land. The migration scenario Radionuclides from waste form to man was assumed particularly for normal release in which Radionuclides discharge from waste form in a series thorough container, buffer, geological, rock, to fracture(fault) and move together with ground water go to biosphere and than go into human body. On this scenario, the parameter such as radionuclides inventory, half life, heat generation, hazard index based on maximum permissible concentration (MPC) or annual limit on intake (ALI) was developed as criteria of reference radionuclides selection. The research concluded that radionuclides inventory, half live, heat generated, hazard index base on MPC or ALI can be used as criteria for selection of reference Radionuclide. The research obtained that the main radionuclides are predicted give the most radiological effect to human are as Cs-137, Sr-90, I-129, Am-243, Cm-244, Pu-238, Pu-239, Pu-240. The radionuclides reasonable to be used as reference radionuclides in safety analysis at spent fuel disposal. (author)

  11. Externally controlled triggered-release of drug from PLGA micro and nanoparticles.

    Directory of Open Access Journals (Sweden)

    Xin Hua

    Full Text Available Biofilm infections are extremely hard to eradicate and controlled, triggered and controlled drug release properties may prolong drug release time. In this study, the ability to externally control drug release from micro and nanoparticles was investigated. We prepared micro/nanoparticles containing ciprofloxacin (CIP and magnetic nanoparticles encapsulated in poly (lactic-co-glycolic acid PLGA. Both micro/nanoparticles were observed to have narrow size distributions. We investigated and compared their passive and externally triggered drug release properties based on their different encapsulation structures for the nano and micro systems. In passive release studies, CIP demonstrated a fast rate of release in first 2 days which then slowed and sustained release for approximately 4 weeks. Significantly, magnetic nanoparticles containing systems all showed ability to have triggered drug release when exposed to an external oscillating magnetic field (OMF. An experiment where the OMF was turned on and off also confirmed the ability to control the drug release in a pulsatile manner. The magnetically triggered release resulted in a 2-fold drug release increase compared with normal passive release. To confirm drug integrity following release, the antibacterial activity of released drug was evaluated in Pseudomonas aeruginosa biofilms in vitro. CIP maintained its antimicrobial activity after encapsulation and triggered release.

  12. Externally controlled triggered-release of drug from PLGA micro and nanoparticles.

    Science.gov (United States)

    Hua, Xin; Tan, Shengnan; Bandara, H M H N; Fu, Yujie; Liu, Siguo; Smyth, Hugh D C

    2014-01-01

    Biofilm infections are extremely hard to eradicate and controlled, triggered and controlled drug release properties may prolong drug release time. In this study, the ability to externally control drug release from micro and nanoparticles was investigated. We prepared micro/nanoparticles containing ciprofloxacin (CIP) and magnetic nanoparticles encapsulated in poly (lactic-co-glycolic acid) PLGA. Both micro/nanoparticles were observed to have narrow size distributions. We investigated and compared their passive and externally triggered drug release properties based on their different encapsulation structures for the nano and micro systems. In passive release studies, CIP demonstrated a fast rate of release in first 2 days which then slowed and sustained release for approximately 4 weeks. Significantly, magnetic nanoparticles containing systems all showed ability to have triggered drug release when exposed to an external oscillating magnetic field (OMF). An experiment where the OMF was turned on and off also confirmed the ability to control the drug release in a pulsatile manner. The magnetically triggered release resulted in a 2-fold drug release increase compared with normal passive release. To confirm drug integrity following release, the antibacterial activity of released drug was evaluated in Pseudomonas aeruginosa biofilms in vitro. CIP maintained its antimicrobial activity after encapsulation and triggered release.

  13. Review of the ecological parameters of radionuclide turnover in vertebrate food chains

    International Nuclear Information System (INIS)

    Kitchings, T.; DiGregorio, D.; Van Voris, P.

    1976-01-01

    Ecological studies of radionuclides in the environment have a long tradition in developing the capability to identify and predict movement and concentration of nuclides in agricultural food chains leading to man. Food chain pathways and transfer coefficients for the nonagricultural portions of natural and managed ecosystems characteristic of affected habitats adjacent to nuclear facilities have not been adequately characterized to establish reliable models for radionuclide releases. This information is necessary in order to assess the impact that such installations will have on the biota of natural ecosystems. Since food chains are the major processes transferring elements from one trophic level to another in terrestrial ecosystems, information is needed on the (a) food-chain transfer pathways, (b) bioconcentration by each trophic component and (c) turnover rates by receptor organisms. These data are prerequisite inputs for food-chain transport models and can be correlated with species characteristics (e.g., body weight and feeding habits), to provide indices for predictive calculations. Application of these models for radionuclide transfer can aid in the assessment of radioactive releases from nuclear reactor facilities to terrestrial nonagricultural food chains

  14. Transfer of radionuclides to animal products following ingestion or inhalation

    International Nuclear Information System (INIS)

    Coughtrey, P.J.

    1996-01-01

    Contamination of animal products forms an important pathway in the transfer of radionuclides from source to man. Simulation of radionuclide transfer via animal products requires an understanding of the processes and mechanisms involved in absorption, distribution, turnover and excretion of radionuclides and related elements in animals as well as knowledge of animal grazing habits and husbandry. This paper provides a summary of the metabolism of important radionuclides in typical domestic animals and of the mathematical approaches that have been used to simulate transfer from diet to animal product. The equilibrium transfer factor approach has been used widely but suffers a number of disadvantages when releases or intakes are variable with time or when intakes are short relative to the lifetime of the animal of interest. Dynamic models, especially those of the compartmental type, have been developed and used widely. Both approaches have benefited from experiences obtained after the Chernobyl accident but a number of uncertainties still exist. Whereas there is now extensive knowledge on the behaviour of radiocaesium in both domestic and wild animals, knowledge of the behaviour of other potentially important radionuclides remains limited. Further experimental and metabolic studies will be required to reduce uncertainties associated with the transfer of radionuclides other than radiocaesium and thereby produce a sound basis for radiological assessments. (author)

  15. Field surveying of radionuclide contamination in forests

    International Nuclear Information System (INIS)

    Turunen, J.; Rantavaara, A.; Ammann, M.

    2009-01-01

    Field measurements of radionuclides after an accidental contamination of forests assume the capacity for identification of a number of nuclides in varying source geometries. The continuous redistribution of radionuclides in forests through natural processes implies a decrease of prevailing surface contamination of trees and an increase in activity density on the ground. Portable gamma spectrometers have long been based on Na(I) detectors which, due to their low energy resolution, are not the tool for analysis of contamination from accidental releases of fission and activation products in the first days or weeks after a deposition. Data of airborne radionuclides from the Chernobyl accident in April 1986 were used for demonstration of initial and later distribution of radionuclides as sources of air Kerma in forests. Forest model (FDMF, PV. 6.0) of the RODOS system was used for the assessment of time-dependent Kerma rate from different forest compartments. The results show the fast reduction of activities of short-lived nuclides and their contributions to the Kerma rate in the first weeks and months. The results also give an estimate for the time needed until a gamma spectrometer with a low energy resolution would give useful information about long-lived radioactivity on the forest floor. An example is given on a portable high resolution semiconductor spectrometer that has suitable characteristics for field surveying also during occurrence of a great number of radionuclides contributing to the gamma spectrum. The needs for further research of a recently deposited radionuclide contamination on forest vegetation and soil, and the efforts for improvement of portable radiation meters and their use in management planning and radioecological research on contaminated forests are discussed. (au)

  16. Methods for determining radionuclide retardation factors: status report

    International Nuclear Information System (INIS)

    Relyea, J.F.; Serne, R.J.; Rai, D.

    1980-04-01

    This report identifies a number of mechanisms that retard radionuclide migration, and describes the static and dynamic methods that are used to study such retardation phenomena. Both static and dynamic methods are needed for reliable safety assessments of underground nuclear-waste repositories. This report also evaluates the extent to which the two methods may be used to diagnose radionuclide migration through various types of geologic media, among them unconsolidated, crushed, intact, and fractured rocks. Adsorption is one mechanism that can control radionuclide concentrations in solution and therefore impede radionuclide migration. Other mechanisms that control a solution's radionuclide concentration and radionuclide migration are precipitation of hydroxides and oxides, oxidation-reduction reactions, and the formation of minerals that might include the radionuclide as a structural element. The retardation mechanisms mentioned above are controlled by such factors as surface area, cation exchange capacity, solution pH, chemical composition of the rock and of the solution, oxidation-reduction potential, and radionuclide concentration. Rocks and ground waters used in determining retardation factors should represent the expected equilibrium conditions in the geologic system under investigation. Static test methods can be used to rapidly screen the effects of the factors mentioned above. Dynamic (or column) testing, is needed to assess the effects of hydrodynamics and the interaction of hydrodynamics with the other important parameters. This paper proposes both a standard method for conducting batch Kd determinations, and a standard format for organizing and reporting data. Dynamic testing methods are not presently developed to the point that a standard methodology can be proposed. Normal procedures are outlined for column experimentation and the data that are needed to analyze a column experiment are identified

  17. Exposure to radionuclides in smoke from vegetation fires

    International Nuclear Information System (INIS)

    Carvalho, Fernando P.; Oliveira, João M.; Malta, Margarida

    2014-01-01

    Naturally occurring radionuclides of uranium, thorium, radium, lead and polonium were determined in bushes and trees and in the smoke from summer forest fires. Activity concentrations of radionuclides in smoke particles were much enriched when compared to original vegetation. Polonium-210 ( 210 Po) in smoke was measured in concentrations much higher than all other radionuclides, reaching 7255 ± 285 Bq kg −1 , mostly associated with the smaller size smoke particles ( 210 Po in surface air near forest fires displayed volume concentrations up to 70 mBq m −3 , while in smoke-free air 210 Po concentration was about 30 μBq m −3 . The estimated absorbed radiation dose to an adult member of the public or a firefighter exposed for 24 h to inhalation of smoke near forest fires could exceed 5 μSv per day, i.e, more than 2000 times above the radiation dose from background radioactivity in surface air, and also higher than the radiation dose from 210 Po inhalation in a chronic cigarette smoker. It is concluded that prolonged exposure to smoke allows for enhanced inhalation of radionuclides associated with smoke particles. Due to high radiotoxicity of alpha emitting radionuclides, and in particular of 210 Po, the protection of respiratory tract of fire fighters is strongly recommended. - Highlights: • Natural radionuclides in vegetation are in low concentrations. • Forest fires release natural radionuclides from vegetation and concentrate them in inhalable ash particles. • Prolonged inhalation of smoke from forest fires gives rise enhanced radiation exposure of lungs especially due to polonium. • Respiratory protection of fire fighters and members of public is highly recommended for radioprotection reasons

  18. Radionuclides transfer into halophytes growing in tidal salt marshes from the Southwest of Spain

    International Nuclear Information System (INIS)

    Luque, Carlos J.; Vaca, Federico; García-Trapote, Ana; Hierro, Almudena; Bolívar, Juan P.; Castellanos, Eloy M.

    2015-01-01

    Estuaries are sinks of materials and substances which are released directly into them or transported from rivers that drain the basin. It is usual to find high organic matter loads and fine particles in the sediments. We analyzed radionuclide concentrations ("2"1"0Po, "2"3"0Th, "2"3"2Th, "2"3"4U, "2"3"8U, "2"2"6Ra, "2"2"8Th, "2"2"8Ra, "4"0K) in sediments and three different organs (roots, stems and leaves) of three species of halophytes plants (Spartina maritima, Spartina densiflora and Sarcocornia perennis). The study was carried out in two tidal salt marshes, one polluted by U-series radionuclides and another nearby that was unpolluted and was used as a control (or reference) area. The Tinto River salt marsh shows high levels of U-series radionuclides coming from mining and industrial discharges. On the contrary, the unperturbed Piedras River salt marsh is located about 25 km from the Tinto marsh, and shows little presence of contaminants and radionuclides. The results of this work have shown that natural radionuclide concentrations (specially the U-isotopes) in the Tinto salt marsh sediments are one order of magnitude higher than those in the Piedras marsh. These radionuclide enhancements are reflected in the different organs of the plants, which have similar concentration increases as the sediments where they have grown. Finally, the transfer factor (TF) of the most polluted radionuclides (U-isotopes and "2"1"0Po) in the Tinto area are one order of magnitude higher than in the Piedras area, indicating that the fraction of each radionuclide in the sediment originating from the pollution is more available for the plants than the indigenous fraction. This means that the plants of the salt marshes are unhelpful as bioindicators or for the phytoremediation of radionuclides. - Highlights: • Radionuclides were analyzed in sediments and plants in unpolluted salt marshes. • Plants uptake radionuclides in all organs in both salt marshes. • The transfer factors

  19. TERRA: a computer code for simulating the transport of environmentally released radionuclides through agriculture

    International Nuclear Information System (INIS)

    Baes, C.F. III; Sharp, R.D.; Sjoreen, A.L.; Hermann, O.W.

    1984-11-01

    TERRA is a computer code which calculates concentrations of radionuclides and ingrowing daughters in surface and root-zone soil, produce and feed, beef, and milk from a given deposition rate at any location in the conterminous United States. The code is fully integrated with seven other computer codes which together comprise a Computerized Radiological Risk Investigation System, CRRIS. Output from either the long range (> 100 km) atmospheric dispersion code RETADD-II or the short range (<80 km) atmospheric dispersion code ANEMOS, in the form of radionuclide air concentrations and ground deposition rates by downwind location, serves as input to TERRA. User-defined deposition rates and air concentrations may also be provided as input to TERRA through use of the PRIMUS computer code. The environmental concentrations of radionuclides predicted by TERRA serve as input to the ANDROS computer code which calculates population and individual intakes, exposures, doses, and risks. TERRA incorporates models to calculate uptake from soil and atmospheric deposition on four groups of produce for human consumption and four groups of livestock feeds. During the environmental transport simulation, intermediate calculations of interception fraction for leafy vegetables, produce directly exposed to atmospherically depositing material, pasture, hay, and silage are made based on location-specific estimates of standing crop biomass. Pasture productivity is estimated by a model which considers the number and types of cattle and sheep, pasture area, and annual production of other forages (hay and silage) at a given location. Calculations are made of the fraction of grain imported from outside the assessment area. TERRA output includes the above calculations and estimated radionuclide concentrations in plant produce, milk, and a beef composite by location

  20. TERRA: a computer code for simulating the transport of environmentally released radionuclides through agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Baes, C.F. III; Sharp, R.D.; Sjoreen, A.L.; Hermann, O.W.

    1984-11-01

    TERRA is a computer code which calculates concentrations of radionuclides and ingrowing daughters in surface and root-zone soil, produce and feed, beef, and milk from a given deposition rate at any location in the conterminous United States. The code is fully integrated with seven other computer codes which together comprise a Computerized Radiological Risk Investigation System, CRRIS. Output from either the long range (> 100 km) atmospheric dispersion code RETADD-II or the short range (<80 km) atmospheric dispersion code ANEMOS, in the form of radionuclide air concentrations and ground deposition rates by downwind location, serves as input to TERRA. User-defined deposition rates and air concentrations may also be provided as input to TERRA through use of the PRIMUS computer code. The environmental concentrations of radionuclides predicted by TERRA serve as input to the ANDROS computer code which calculates population and individual intakes, exposures, doses, and risks. TERRA incorporates models to calculate uptake from soil and atmospheric deposition on four groups of produce for human consumption and four groups of livestock feeds. During the environmental transport simulation, intermediate calculations of interception fraction for leafy vegetables, produce directly exposed to atmospherically depositing material, pasture, hay, and silage are made based on location-specific estimates of standing crop biomass. Pasture productivity is estimated by a model which considers the number and types of cattle and sheep, pasture area, and annual production of other forages (hay and silage) at a given location. Calculations are made of the fraction of grain imported from outside the assessment area. TERRA output includes the above calculations and estimated radionuclide concentrations in plant produce, milk, and a beef composite by location.

  1. Analyses of human exposures to alpha-emitting radionuclides from nuclear fuel cycles

    International Nuclear Information System (INIS)

    Cuddihy, R.G.; McClellan, R.O.; Griffith, W.C.; Hoover, M.D.

    1977-01-01

    Human populations may potentially be exposed to alpha-emitting radionuclides released to the environment from a variety of activities associated with nuclear fuel cycles. Generally, the most important exposure pathway is by way of inhalation. This can occur soon after release of these substances or after they have been deposited on ground surfaces and resuspended with soil particles. Estimating the potential magnitude of these exposures is usually done through the use of mathematical models accounting for the dispersion of the released material through the environment and its uptake by people living near the nuclear facilities. Studies described in this paper suggest that these exposures can probably be estimated within a factor of 10 based upon our previous experience with measured human organ levels of other trace metals taken up from the environment. It should also be noted that variability among individuals within the population may result in a few percent accumulating more than 10 times the geometric mean of the internal organ radionuclide burdens

  2. The speciation of radionuclides in sediments and soils. Part II. Studies with a sequential organic extraction procedure

    International Nuclear Information System (INIS)

    Voss, H.A.; Williams, G.A.; Cooper, M.B.

    1983-07-01

    A series of chemical extractions with a range of organic solvents has been performed to investigate the speciation of radionuclides in soil and sediment samples from the Mt. Brockman area in the Northern Territory. The major result is that of all the organic solvents used in the extractions, only acetic acid removes large proportions of the radionuclides 210 Pb (ca. 30-70%) and 226 Ra (10-55%) from the soil and sediment samples. The failure of the other organic solvents, and in particular dimethylformamide, to extract appreciable amounts of these radionuclides is taken to indicate that 210 Pb and 226 Ra are not present as discrete metal complexes of organic ligands. The overriding conclusion, that the acidic nature of the solvent is the most important property in releasing the bound radionuclides into solution, suggests that even under mildly acidic conditions encountered in the environment significant amounts of 210 Pb and 226 Ra may be released for transportation

  3. Massive radiological releases profoundly differ from controlled releases

    International Nuclear Information System (INIS)

    Pascucci-Cahen, Ludivine; Patrick, Momal

    2012-11-01

    Preparing for a nuclear accident implies understanding potential consequences. While many specialized experts have been working on different particular aspects, surprisingly little effort has been dedicated to establishing the big picture and providing a global and balanced image of all major consequences. IRSN has been working on the cost of nuclear accidents, an exercise which must strive to be as comprehensive as possible since any omission obviously underestimates the cost. It therefore provides (ideally) an estimate of all cost components, thus revealing the structure of accident costs, and hence sketching a global picture. On a French PWR, it appears that controlled releases would cause an 'economical' accident with limited radiological consequences when compared to other costs; in contrast, massive releases would trigger a major crisis with strong radiological consequences. The two types of crises would confront managers with different types of challenges. (authors)

  4. Modelling of the radionuclide transport through terrestrial food chains

    International Nuclear Information System (INIS)

    Hanusik, V.

    1991-01-01

    The paper presents a terrestrial food chains model for computing potential human intake of radionuclides released into the atmosphere during normal NPP operation. Attention is paid to the choice of model parameter values. Results obtained by our approach are compared to those applied in current methodology. (orig.) [de

  5. Controlled Release Formulations of Auxinic Herbicides

    Science.gov (United States)

    Kowalski, Witold J.; Siłowiecki, Andrzej.; Romanowska, Iwona; Glazek, Mariola; Bajor, Justyna; Cieciwa, Katarzyna; Rychter, Piotr

    2013-04-01

    Controlled release formulations are applied extensively for the release of active ingredients such as plant protection agents and fertilizers in response to growing concern for ecological problems associated with increased use of plant protection chemicals required for intensive agricultural practices [1]. We synthesized oligomeric mixtures of (R,S)-3-hydroxy butyric acid chemically bonded with 2,4-D, Dicamba and MCPA herbicides (HBA) respectively, and determined their molecular structure and molecular weight dispersion by the size exclusion chromatography, proton magnetic resonance spectrometry and electro-spray ionization mass spectrometry. Further we carried out bioassays of herbicidal effectiveness of the HBA herbicides vs. series of dicotyledonous weeds and crop injury tests [2, 3, 4]. Field bioassays were accomplished according to the EPPO standards [5]. Groups of representative weeds (the development stages in the BCCH scale: 10 - 30) were selected as targets. Statistical variabilities were assessed by the Fisher LSD test for plants treated with the studied herbicides in form of HBA oligomers, the reference herbicides in form of dimethyl ammonium salts (DMA), and untreated plants. No statistically significant differences in the crop injuries caused by the HBA vs. the DMA reference formulation were observed. The effectiveness of the HBA herbicides was lower through the initial period (ca. 2 weeks) relative to the DMA salts, but a significant increase in the effectiveness of the HBA systems followed during the remaining fraction of each assay. After 6 weeks all observed efficiencies approached 100%. The death of weeds treated with the HBA herbicides was delayed when compared with the DMA reference herbicides. The delayed uptake observed for the HBA oligomers relative to the DMA salts was due to controlled release phenomena. In case of the DMA salts the total amount of active ingredients was available at the target site. By contrast, the amount of an active

  6. Effects of radionuclide decay on waste glass behavior: A critical review

    International Nuclear Information System (INIS)

    Wronkiewicz, D.J.

    1993-12-01

    This paper is an extension of a chapter in an earlier report [1] that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact

  7. Electrosprayed nanoparticle delivery system for controlled release

    Energy Technology Data Exchange (ETDEWEB)

    Eltayeb, Megdi, E-mail: megdi.eltayeb@sustech.edu [Department of Biomedical Engineering, Sudan University of Science and Technology, PO Box 407, Khartoum (Sudan); Stride, Eleanor, E-mail: eleanor.stride@eng.ox.ac.uk [Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Old Road Campus Research Building, Headington OX3 7DQ (United Kingdom); Edirisinghe, Mohan, E-mail: m.edirisinghe@ucl.ac.uk [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Harker, Anthony, E-mail: a.harker@ucl.ac.uk [London Centre for Nanotechnology, Gordon Street, London WC1H 0AH (United Kingdom); Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2016-09-01

    This study utilises an electrohydrodynamic technique to prepare core-shell lipid nanoparticles with a tunable size and high active ingredient loading capacity, encapsulation efficiency and controlled release. Using stearic acid and ethylvanillin as model shell and active ingredients respectively, we identify the processing conditions and ratios of lipid:ethylvanillin required to form nanoparticles. Nanoparticles with a mean size ranging from 60 to 70 nm at the rate of 1.37 × 10{sup 9} nanoparticles per minute were prepared with different lipid:ethylvanillin ratios. The polydispersity index was ≈ 21% and the encapsulation efficiency ≈ 70%. It was found that the rate of ethylvanillin release was a function of the nanoparticle size, and lipid:ethylvanillin ratio. The internal structure of the lipid nanoparticles was studied by transmission electron microscopy which confirmed that the ethylvanillin was encapsulated within a stearic acid shell. Fourier transform infrared spectroscopy analysis indicated that the ethylvanillin had not been affected. Extensive analysis of the release of ethylvanillin was performed using several existing models and a new diffusive release model incorporating a tanh function. The results were consistent with a core-shell structure. - Highlights: • Electrohydrodynamic spraying is used to produce lipid-coated nanoparticles. • A new model is proposed for the release rates of active components from nanoparticles. • The technique has potential applications in food science and medicine. • Electrohydrodynamic processing controlled release lipid nanoparticles.

  8. Effects of culinary preparation on radionuclide levels in vegetable foodstuffs

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, B.T.; Bradley, E.J.; Dodd, N.J.

    1987-01-01

    Vegetables contaminated by fall-out from the Chernobyl nuclear reactor accident have been used to investigate how simple culinary methods can affect the levels of various radionuclides in the portion consumed by man. Only ..gamma.. ray emitting radionuclides were investigated. Those parts of vegetables normally considered inedible, for example coarse outer leaves, foliage or roots, can account for between 50% and 97% of the total radionuclide content. Washing of the edible parts of vegetables can reduce the levels still further, although the efficacy is dependent on both the radionuclide and the vegetable type. These normal domestic procedures can reduce intakes of recently deposited radionuclides on vegetables by about an order of magnitude. The results have implications for the scope of monitoring programmes that might follow any future accidental release. They also reinforce very strongly the requirement for measurements on edible parts rather than whole samples as a direct input to dose evaluation. These results further suggest that there is no need to revise the general assumptions made in accident consequence models regarding losses of activity between harvest and consumption. However, more rigorous assessments of dose should take account of vegetable type and probable means of preparation.

  9. Application of probability distributions for quantifying uncertainty in radionuclide source terms for Seabrook risk assessment

    International Nuclear Information System (INIS)

    Walker, D.H.; Savin, N.L.

    1985-01-01

    The calculational models developed for the Reactor Safety Study (RSS) have traditionally been used to generate 'point estimate values' for radionuclide release to the environment for nuclear power plant risk assessments. The point estimate values so calculated are acknowledged by most knowledgeable individuals to be conservatively high. Further, recent evaluations of the overall uncertainties in the various components that make up risk estimates for nuclear electric generating stations show that one of the large uncertainties is associated with the magnitude of the radionuclide release to the environment. In the approach developed for the RSS, values for fission product release from the fuel are derived from data obtained from small experiments. A reappraisal of the RSS release fractions was published in 1981 in NUREG-0772. Estimates of fractional releases from fuel are similar to those of the RSS. In the RSS approach, depletion during transport from the core (where the fission products are released) to the containment is assumed to be zero for calculation purposes. In the containment, the CORRAL code is applied to calculate radioactivity depletion by containment processes and to calculate the quantity and timing of release to the environment

  10. Potential for radionuclide immobilization in the EBS/NFE: solubility limiting phases for neptunium, plutonium, and uranium

    Energy Technology Data Exchange (ETDEWEB)

    Rard, J. A., LLNL

    1997-10-01

    Retardation and dispersion in the far field of radionuclides released from the engineered barrier system/near field environment (EBS/NFE) may not be sufficient to prevent regulatory limits being exceeded at the accessible environment. Hence, a greater emphasis must be placed on retardation and/or immobilization of radionuclides in the EBS/NFE. The present document represents a survey of radionuclide-bearing solid phases that could potentially form in the EBS/NFE and immobilize radionuclides released from the waste package and significantly reduce the source term. A detailed literature search was undertaken for experimental solubilities of the oxides, hydroxides, and various salts of neptunium, plutonium, and uranium in aqueous solutions as functions of pH, temperature, and the concentrations of added electrolytes. Numerous solubility studies and reviews were identified and copies of most of the articles were acquired. However, this project was only two months in duration, and copies of some the identified solubility studies could not be obtained at short notice. The results of this survey are intended to be used to assess whether a more detailed study of identified low- solubility phase(s) is warranted, and not as a data base suitable for predicting radionuclide solubility. The results of this survey may also prove useful in a preliminary evaluation of the efficacy of incorporating chemical additives to the EBS/NFE that will enhance radionuclide immobilization.

  11. Optimization of production and quality control of therapeutic radionuclides and radiopharmaceuticals. Final report of a co-ordinated research project 1994-1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-09-01

    The `renaissance` of the therapeutic applications of radiopharmaceuticals during the last few years was in part due to a greater availability of radionuclides with appropriate nuclear decay properties, as well as to the development of carrier molecules with improved characteristics. Although radionuclides such as {sup 32}P, {sup 89}Sr and {sup 131}I, were used from the early days of nuclear medicine in the late 1930s and early 1940s, the inclusion of other particle emitting radionuclides into the nuclear medicine armamentarium was rather late. Only in the early 1980s did the specialized scientific literature start to show the potential for using other beta emitting nuclear reactor produced radionuclides such as {sup 153}Sm, {sup 166} Ho, {sup 165}Dy and {sup 186-188}Re. Bone seeking agents radiolabelled with the above mentioned beta emitting radionuclides demonstrated clear clinical potential in relieving intense bone pain resulting from metastases of the breast, prostate and lung of cancer patients. Therefore, upon the recommendation of a consultants meeting held in Vienna in 1993, the Co-ordinated Research Project (CRP) on Optimization of the Production and quality control of Radiotherapeutic Radionuclides and Radiopharmaceuticals was established in 1994. The CRP aimed at developing and improving existing laboratory protocols for the production of therapeutic radionuclides using existing nuclear research reactors including the corresponding radiolabelling, quality control procedures; and validation in experimental animals. With the participation of ten scientists from IAEA Member States, several laboratory procedures for preparation and quality control were developed, tested and assessed as potential therapeutic radiopharmaceuticals for bone pain palliation. In particular, the CRP optimised the reactor production of {sup 153}Sm and the preparation of the radiopharmaceutical {sup 153}Sm-EDTMP (ethylene diamine tetramethylene phosphonate), as well as radiolabelling

  12. Modeling of radionuclide transport through rock formations and the resulting radiation exposure of reference persons. Calculations using Asse II parameters

    International Nuclear Information System (INIS)

    Kueppers, Christian; Ustohalova, Veronika; Steinhoff, Mathias

    2012-01-01

    The long-term release of radioactivity into the ground water path cannot be excluded for the radioactive waste repository Asse II. The possible radiological consequences were analyzed using a radio-ecological scenario developed by GRS. A second scenario was developed considering the solubility of radionuclides in salt saturated solutions and retarding/retention effects during the radionuclide transport through the cap rock layers. The modeling of possible radiation exposure was based on the lifestyle habits of reference persons. In Germany the calculation procedure for the prediction of radionuclide release from final repositories is not defined by national standards, the used procedures are based on analogue methods from other radiation protection calculations.

  13. Meltable magnetic biocomposites for controlled release

    Energy Technology Data Exchange (ETDEWEB)

    Müller, R., E-mail: robert.mueller@ipht-jena.de [Leibniz Institute of Photonic Technology (IPHT), P.O.B. 100239, Jena, D-07702 Germany (Germany); Zhou, M. [Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstrasse 10, Jena, D-07743 Germany (Germany); Dellith, A. [Leibniz Institute of Photonic Technology (IPHT), P.O.B. 100239, Jena, D-07702 Germany (Germany); Liebert, T.; Heinze, T. [Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstrasse 10, Jena, D-07743 Germany (Germany)

    2017-06-01

    New biocompatible composites with adjustable melting point in the range of 30–140 °C, consisting of magnetite nanoparticles embedded into a matrix of meltable dextran fatty acid ester are presented which can be softened under an induced alternating magnetic field (AMF). The chosen thermoplastic magnetic composites have a melting range close to human body temperature and can be easily shaped into disk or coating film under melting. The composite disks were loaded with green fluorescent protein (GFP) as a model protein. Controlled release of the protein was realized with high frequent alternating magnetic field of 20 kA/m at 400 kHz. These results showed that under an AMF the release of GFP from magnetic composite was accelerated compared to the control sample without exposure to AMF. Furthermore a texturing of particles in the polymer matrix by a static magnetic field was investigated. - Highlights: • Thermoplastic biocomposite are prepared from dextran ester and magnetite particles. • The composite can be heated by an AC magnetic field above the melting temperature. • In molten state texturing of particles is possible and improves the heating ability. • The biopolymer could be used as a remote controlled matrix for protein release.

  14. Radionuclides in the study of marine processes

    International Nuclear Information System (INIS)

    Kershaw, P.J.; Woodhead, D.S.

    1991-01-01

    For many years, the radioactive properties of the naturally occurring radionuclides have been used to determine their distributions in the marine environment and, more generally, to gain an understanding of the dynamic processes which control their behaviour in attaining these distributions. More recently the inputs from human activities of both natural and artificial (i.e. man-made) radionuclides have provided additional opportunities for the study of marine processes on local, regional and global scales. The primary objective of the symposium is to provide a forum for an open discussion of the insights concerning processes in the marine environment which can be gained from studies of radionuclide behaviour. Papers have been grouped within the following principal themes; the uses of radionuclides as tracers of water transport; scavenging and particulate transport processes in the oceans as deduced from radionuclide behaviour; processes in the seabed and radionuclides in biological systems. (Author)

  15. The study of atmospheric dispersion of radionuclide near nuclear power plant using CFD approach

    International Nuclear Information System (INIS)

    Nagrale, Dhanesh B.; Bera, Subrata; Deo, Anuj K.; Gaikwad, Avinash J.

    2015-01-01

    Most of the studies on atmospheric dispersion of radioactive material released from nuclear power plants are based on Gaussian plume models which fail to take account turbulence generated. The Fire Dynamic Simulator (FDS) code is one such flow model that uses a form of Navier-Stokes equation for low mach number applications. In the 0-2 km range near nuclear power plant, mainly near the source of emission of radionuclides, obstructions like natural draft cooling towers, plant building and structures are located. The stability class 'F' conditions and temperature of surrounding atmosphere, 15°C are considered in analysis. Main constituents of radionuclides released from stack mainly xenon, krypton. Two cases are carried out a) dispersion of gases without obstruction of cooling tower and b) dispersion of gases with obstruction of cooling tower. It is observed that mass fraction of radionuclides near the cooling tower ground increased to certain extent due to obstruction and wake effect. (author)

  16. Transfer of accidentally released radionuclides in agricultural systems (TARRAS)

    International Nuclear Information System (INIS)

    Cancio, D.; Maubert, Colle; Rauret, G.; Grandison, A.S.

    1993-01-01

    The aim of this project is to contribute to the reliability of radiological assessment methods and establish a scientific base for the design of post-accident countermeasures. Three main aspects are considered in this project: A simulated accidental source term is used and the behaviour of aerosol deposits containing Sr, Cs and Ag isotopes are followed in some European soil-crop systems; the modification of radionuclide transfer rates through the food chain by well established food processing techniques is studied for Sr, Cs, Co and Ru; the project includes a study on the specific mediterranean diet and transfer data that are compared with currently used generic parameters. Seven contributions of the project for the reporting period are presented. (R.P.) 11 figs., 12 tabs

  17. Fukushima Daiichi-Derived Radionuclides in the Ocean: Transport, Fate, and Impacts.

    Science.gov (United States)

    Buesseler, Ken; Dai, Minhan; Aoyama, Michio; Benitez-Nelson, Claudia; Charmasson, Sabine; Higley, Kathryn; Maderich, Vladimir; Masqué, Pere; Morris, Paul J; Oughton, Deborah; Smith, John N

    2017-01-03

    The events that followed the Tohoku earthquake and tsunami on March 11, 2011, included the loss of power and overheating at the Fukushima Daiichi nuclear power plants, which led to extensive releases of radioactive gases, volatiles, and liquids, particularly to the coastal ocean. The fate of these radionuclides depends in large part on their oceanic geochemistry, physical processes, and biological uptake. Whereas radioactivity on land can be resampled and its distribution mapped, releases to the marine environment are harder to characterize owing to variability in ocean currents and the general challenges of sampling at sea. Five years later, it is appropriate to review what happened in terms of the sources, transport, and fate of these radionuclides in the ocean. In addition to the oceanic behavior of these contaminants, this review considers the potential health effects and societal impacts.

  18. Radionuclides in the food chain

    International Nuclear Information System (INIS)

    Harley, J.H.; Schmidt, G.D.

    1988-01-01

    Radionuclides in the Food Chain reviews past experience in meeting the challenge of radionuclide contamination of foodstuffs and water sources and, in the wake of the reactor accidents at Chernobyl and Three Mile Island, presents current concepts and programs relating to measurement, surveillance, effects, risk management, evaluation guidelines, and control and regulatory activities. This volume, based on a symposium sponsored by the International Life Sciences Institute in association with the International Institute for Applied Systems Analysis, which brought together both radiation experts and food industry policymakers, examines such vital topics as structural problems in large-scale crisis-managment systems; dose assessment from man-made sources; international recommendations on radiation protection; airborne contamination, as well as aquatic and soilborne radionuclides; food-chain contamination from testing nuclear devices; long-term health effects of radionuclides in food and water supplies; and use of mathematical models in risk assessment and management. (orig.)

  19. An overview of Fukushima radionuclides measured in the northern hemisphere

    International Nuclear Information System (INIS)

    Thakur, P.; Ballard, S.; Nelson, R.

    2013-01-01

    The Great East Japan Earthquake and tsunami on March 11, 2011 resulted in the tragic accident at the Fukushima Nuclear Power Plant (NPP) and subsequently uncontrolled release of radioactive contaminants into the atmosphere. This review article attempts to compile and interpret data collected by various national and international monitoring networks in response to the Fukushima releases across the northern hemisphere. The majority of the releases occurred during the period March 12–22 with a maximum release phase from March 14–17, 2011. The radioactivity released was dominated by volatile fission products including isotopes of the noble gases (xenon and krypton), iodine, cesium, and tellurium. The radioactive gases and particles released in the accident were dispersed over the middle latitudes of the entire northern hemisphere and for the first time also measured in the southern Hemisphere. Isotopes of iodine and cesium were detected in air, water, milk and food samples collected across the entire northern hemisphere. Elevated levels of fission products were detected from March to May 2011 at many locations over the northern hemisphere. This article focuses on the most prevalent cesium and iodine isotopes, but other secondary isotopes are also discussed. Spatial and temporal patterns and differences are contrasted. The activity ratios of 131 I/ 137 Cs and 134 Cs/ 137 Cs measured at several locations are evaluated to gain an insight into the fuel burn-up, the inventory of radionuclides in the reactor and the isotopic signature of the accident. It is important to note that all of the radiation levels detected outside of Japan have been very low and are well below any level of public and environmental hazard. - Graphical abstract: The trace levels of radioactivity in air, water, and milk samples collected across the northern hemisphere between March–May, 2011 from the damaged Fukushima Daiichi nuclear power plant, Japan are discussed. Highlights: • We report

  20. An overview of Fukushima radionuclides measured in the northern hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, P., E-mail: pthakur@cemrc.org [Carlsbad Environmental Monitoring and Research Center, 1400 University Drive, Carlsbad, NM 88220 (United States); Ballard, S. [Carlsbad Environmental Monitoring and Research Center, 1400 University Drive, Carlsbad, NM 88220 (United States); Nelson, R. [Department of Energy, Carlsbad Field Office, 4021, National Parks Hwy, Carlsbad, NM 88220 (United States)

    2013-08-01

    The Great East Japan Earthquake and tsunami on March 11, 2011 resulted in the tragic accident at the Fukushima Nuclear Power Plant (NPP) and subsequently uncontrolled release of radioactive contaminants into the atmosphere. This review article attempts to compile and interpret data collected by various national and international monitoring networks in response to the Fukushima releases across the northern hemisphere. The majority of the releases occurred during the period March 12–22 with a maximum release phase from March 14–17, 2011. The radioactivity released was dominated by volatile fission products including isotopes of the noble gases (xenon and krypton), iodine, cesium, and tellurium. The radioactive gases and particles released in the accident were dispersed over the middle latitudes of the entire northern hemisphere and for the first time also measured in the southern Hemisphere. Isotopes of iodine and cesium were detected in air, water, milk and food samples collected across the entire northern hemisphere. Elevated levels of fission products were detected from March to May 2011 at many locations over the northern hemisphere. This article focuses on the most prevalent cesium and iodine isotopes, but other secondary isotopes are also discussed. Spatial and temporal patterns and differences are contrasted. The activity ratios of {sup 131}I/{sup 137}Cs and {sup 134}Cs/{sup 137}Cs measured at several locations are evaluated to gain an insight into the fuel burn-up, the inventory of radionuclides in the reactor and the isotopic signature of the accident. It is important to note that all of the radiation levels detected outside of Japan have been very low and are well below any level of public and environmental hazard. - Graphical abstract: The trace levels of radioactivity in air, water, and milk samples collected across the northern hemisphere between March–May, 2011 from the damaged Fukushima Daiichi nuclear power plant, Japan are discussed. Highlights

  1. RIVER-RAD: A computer code for simulating the transport of radionuclides in rivers

    International Nuclear Information System (INIS)

    Hetrick, D.M.; McDowell-Boyer, L.M.; Sjoreen, A.L.; Thorne, D.J.; Patterson, M.R.

    1992-11-01

    A screening-level model, RIVER-RAD, has been developed to assess the potential fate of radionuclides released to rivers. The model is simplified in nature and is intended to provide guidance in determining the potential importance of the surface water pathway, relevant transport mechanisms, and key radionuclides in estimating radiological dose to man. The purpose of this report is to provide a description of the model and a user's manual for the FORTRAN computer code

  2. Radiation monitoring for radionuclide release in water system resulted from nuclear power plant operation

    International Nuclear Information System (INIS)

    Vintsukevich, N.V.; Tomilin, Yu.A.

    1983-01-01

    Pre-operational investigation into environmental radioactivity in the vicinity of Yuzhno-Ukrainskaya NPP with reverse- direct flow cooling scheme of circulating water was conducted. Considering that reservoir-coolant of NPP will be connected constantly with water reservoirs located on the Yuzhnyj Bug river possibilities of radionuclide accumulation in different river components - 5ilt, algae, river water-were investigated. It was established that increase of pH and salt concentration in water of river undercurrent create the conditions for formation of radionuclide sedimentary forms, increase their accumulation in bottom sediments and aqquatic vegetation. The conclusion on the necessity of constant radiation monitoring for relase of liquid coastes of Yuzhno-Ukrainskaya NPP in the Yuzhnyj Bug river is drawn

  3. Background information on sources of low-level radionuclide emissions to air

    International Nuclear Information System (INIS)

    Corbit, C.D.; Herrington, W.N.; Higby, D.P.; Stout, L.A.; Corley, J.P.

    1983-09-01

    This report provides a general description and reported emissions for eight low-level radioactive source categories, including facilties that are licensed by the Nuclear Regulatory Commission (NRC) and Agreement States, and non-Department of Energy (DOE) federal facilities. The eight categories of low-level radioactive source facilities covered by this report are: research and test reactors, accelerators, the radiopharmaceutical industry, source manufacturers, medical facilities, laboratories, naval shipyards, and low-level commercial waste disposal sites. Under each category five elements are addressed: a general description, a facility and process description, the emission control systems, a site description, and the radionuclides released to air (from routine operations)

  4. Background information on sources of low-level radionuclide emissions to air

    Energy Technology Data Exchange (ETDEWEB)

    Corbit, C.D.; Herrington, W.N.; Higby, D.P.; Stout, L.A.; Corley, J.P.

    1983-09-01

    This report provides a general description and reported emissions for eight low-level radioactive source categories, including facilties that are licensed by the Nuclear Regulatory Commission (NRC) and Agreement States, and non-Department of Energy (DOE) federal facilities. The eight categories of low-level radioactive source facilities covered by this report are: research and test reactors, accelerators, the radiopharmaceutical industry, source manufacturers, medical facilities, laboratories, naval shipyards, and low-level commercial waste disposal sites. Under each category five elements are addressed: a general description, a facility and process description, the emission control systems, a site description, and the radionuclides released to air (from routine operations).

  5. Radiopharmaceuticals and other compounds labelled with short-lived radionuclides

    CERN Document Server

    Welch, Michael J

    2013-01-01

    Radiopharmaceuticals and Other Compounds Labelled with Short-Lived Radionuclides covers through both review and contributed articles the potential applications and developments in labeling with short-lived radionuclides whose use is restricted to institutions with accelerators. The book discusses the current and potential use of generator-produced radionuclides as well as other short-lived radionuclides, and the problems of quality control of such labeled compounds. The book is useful to nuclear medicine physicians.

  6. Doses in various parts of the biosphere due to long-lived radionuclides originating from deep geological repositories

    International Nuclear Information System (INIS)

    Bergstroem, U.; Karlsson, Sara; Nordlinder, S.

    1999-01-01

    Turnover of radionuclides and resulting doses to man were modelled for various parts of the biosphere. This was made for different scenarios of leakage of radionuclides from a deep geological repository for spent nuclear fuel and other waste. In previous studies, the emphasis was on doses from contaminated ground water represented by a well or various surface waters. This was because radionuclides were assumed to be released directly to surface water, the use of which subsequently formed the major pathway for radionuclides to agricultural areas. In the present study, radionuclides were considered to reach lakes, running waters, coastal areas, agricultural areas and peat areas. The inflow of radionuclides to agricultural areas was supposed to be from below. Doses due to direct use of contaminated ground water from a well were also considered. Altogether 44 radionuclides contained in the waste were assumed to be released during 10,000 years, with a rate of 1 Bq/year of each radionuclide, to each of the above mentioned biospheric parts. During that time, the biospheric conditions were assumed to be the same as they are today. Doses to the critical group were calculated by exposure pathways specific for each entry-point All calculations were performed with estimation of confidence due to time-dependent parameter variation and uncertainty in input values. The results indicate that drinking water from wells is not a critical exposure pathway for all studied radionuclides. Instead, inflow of contaminated water to soil and peat bogs may be crucial for illustration of doses for geological high-level waste disposal. Improved knowledge of processes at the geosphere-biosphere interface is therefore important

  7. Controlled Release Formulation of Indomethacin Prepared With Bee ...

    African Journals Online (AJOL)

    Erah

    2010-12-27

    Dec 27, 2010 ... Results: The results show that, although the release rate of formulations F1 - F7 did not show any ... Keywords: Propolis (bee glue), Indomethacin, Controlled release, Zero order kinetics, Waxy materials ... focus of interest.

  8. The contamination of the oceans by anthropogenic radionuclides

    International Nuclear Information System (INIS)

    Figueira, Rubens C.L.; Cunha, Ieda I.L.

    1998-01-01

    Several hundreds of artificial of artificial radionuclides are produced as the result of human activities, such as the applications of nuclear reactors and particle accelerators, testing of nuclear weapons and nuclear accidents. Many of these radionuclides are short-lived and decay quickly after their production, but some of them are longer-lived and are released into the environment. From the radiological point of view the most important radionuclides are cesium-137, strontium-90 and plutonium-239, due to their chemical and nuclear characteristics. The two first radioisotopes present long half life (30 and 28 years), high fission yields and chemical behaviour similar to potassium and calcium, respectively. No stable element exists for plutonium-239, that presents high radiotoxity, longh half-life (24000 years) and some marine organisms accumulate plutonium at high levels. The radionuclides introduced into marine environment undergo various physical, chemical and biological processes taking place in the sea. These processes may be due to physical, dispersion or complicated chemical and biological interactions of the radionuclides with inorganic and organic suspend matter, variety of living organism, bottom sediments, etc. The behaviour of radionuclides in the sea depends primarily on their chemical properties, but it may also be influenced by properties of interacting matrices and other environmental factors. The major route of radiation exposure of man to artificial radionuclides occuring in the marine environment is through ingestion of radiologically contamined marine organisms. This paper summarizes the main sources of contamination in the marine environment and presents an overview covering the oceanic distribution of anthropogenic radionuclides in the FAO regions. A great number of measurements of artificial radioclides have been carried out on various marine environmental samples in different oceans over the world, being cesium-137 the most widely measured

  9. Radionuclides in an arctic terrestrial ecosystem affected by atmospheric release from the Kraton-3 accidental underground nuclear explosion. 2001-2002

    International Nuclear Information System (INIS)

    Ramzaev, V.; Golikov, V.; Mishine, A.; Kaduka, M.; Burtcev, I.; Gedeonov, A.; Bulatenkov, Y.U.; Strand, P.; Brown, J.

    2004-01-01

    Current distributions of artificial radionuclides (ARN) were studied in the main compartments of a larch-tree forest lethally affected by a radioactive release from the Kraton-3 peaceful underground nuclear explosion (65.9 deg N, 112.3 deg E; Yakutia, Russia; 1978). Samples of soil, fungi, lichens, mosses, grasses, shrubs and trees were obtained at points belonging to four zones categorised by the severity of the ecosystem damage. Sampling was supplemented by dose rate measurements in air and mapping. The area of forest characterised by 100% lethality to adult larches (Larix gmelinii) and with partial, visually-detectable damage of other more radio-resistance species (e.g. lichens, mosses) covers a territory of approximately 1.2 km 2 . Elevated levels of long-lived ARN were found at all sampling sites. Maximum registered levels of the ground contamination with radionuclides of Cs, Sr and Pu were three orders of magnitude higher than those expected from global fallout. The ratios of 137 Cs to some other significant radionuclides in the ground contamination were as follows [mean (range)]: 90 Sr - 0.57(0.02-0.93); 239,240 Pu 44(25-72); 60 Co 470(220-760). Twenty-three years after a discrete contamination event, 90-95% of the total deposited radiocesium and plutonium has still remained in the lichen-moss on-ground cover and in the top 5 cm organic soil layer. At the same time, vertical and horizontal migrations of 90 Sr in soil were more pronounced. Strong surface contamination with 137 Cs, 90 Sr and plutonium was detected at the twigs and bark of the dead larches. The young larches that grew at the contaminated area following the initial destruction of the forest demonstrated a substantial ability to accumulate 137 Cs, 90 Sr and plutonium via roots, while the bushes selectively accumulated mainly radiostrontium. In contrast, some fungi concentrated mostly radiocesium. The levels of gamma dose rate in air and the environmental contamination with 137 Cs were found to

  10. RADIONUCLIDE DISPERSION RATES BY AEOLIAN, FLUVIAL, AND POROUS MEDIA TRANSPORT

    International Nuclear Information System (INIS)

    Walton, J.; Goodell, P.; Brashears, C.; French, D.; Kelts, A.

    2005-01-01

    Radionuclide transport was measured from high grade uranium ore boulders near the Nopal I Site, Chihuahua, Mexico. High grade uranium ore boulders were left behind after removal of a uranium ore stockpile at the Prior High Grade Stockpile (PHGS). During the 25 years when the boulder was present, radionuclides were released and transported by sheetflow during precipitation events, wind blown resuspension, and infiltration into the unsaturated zone. In this study, one of the boulders was removed, followed by grid sampling of the surrounding area. Measured gamma radiation levels in three dimensions were used to derive separate dispersion rates by the three transport mechanisms

  11. RADIONUCLIDE DISPERSION RATES BY AEOLIAN, FLUVIAL, AND POROUS MEDIA TRANSPORT

    Energy Technology Data Exchange (ETDEWEB)

    J. Walton; P. Goodell; C. Brashears; D. French; A. Kelts

    2005-07-11

    Radionuclide transport was measured from high grade uranium ore boulders near the Nopal I Site, Chihuahua, Mexico. High grade uranium ore boulders were left behind after removal of a uranium ore stockpile at the Prior High Grade Stockpile (PHGS). During the 25 years when the boulder was present, radionuclides were released and transported by sheetflow during precipitation events, wind blown resuspension, and infiltration into the unsaturated zone. In this study, one of the boulders was removed, followed by grid sampling of the surrounding area. Measured gamma radiation levels in three dimensions were used to derive separate dispersion rates by the three transport mechanisms.

  12. Field studies of radionuclide transport at the Chalk River Laboratories

    International Nuclear Information System (INIS)

    Champ, D.R.; Killey, R.W.D.; Moltyaner, G.L.

    1991-01-01

    In this paper the authors summarize the results of: in situ field column experiments to study the transport behaviour of several long-lived radionuclides, 4 natural gradient non-reactive radiotracer injection experiments at the Chalk River Laboratories (CRL) Twin Lake Tracer Test Site, and a model validation study that used data for 90 Sr from two well-defined contaminated groundwater flow systems at CRL. The paper also describes a current re-evaluation of radionuclide release and transport from a 1960 experimental burial (in a CRL sand aquifer) of glass blocks containing fission and activation products. (J.P.N.)

  13. Exposure to radionuclides in smoke from vegetation fires

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fernando P., E-mail: carvalho@itn.pt; Oliveira, João M.; Malta, Margarida

    2014-02-01

    Naturally occurring radionuclides of uranium, thorium, radium, lead and polonium were determined in bushes and trees and in the smoke from summer forest fires. Activity concentrations of radionuclides in smoke particles were much enriched when compared to original vegetation. Polonium-210 ({sup 210}Po) in smoke was measured in concentrations much higher than all other radionuclides, reaching 7255 ± 285 Bq kg{sup −1}, mostly associated with the smaller size smoke particles (< 1.0 μm). Depending on smoke particle concentration, {sup 210}Po in surface air near forest fires displayed volume concentrations up to 70 mBq m{sup −3}, while in smoke-free air {sup 210}Po concentration was about 30 μBq m{sup −3}. The estimated absorbed radiation dose to an adult member of the public or a firefighter exposed for 24 h to inhalation of smoke near forest fires could exceed 5 μSv per day, i.e, more than 2000 times above the radiation dose from background radioactivity in surface air, and also higher than the radiation dose from {sup 210}Po inhalation in a chronic cigarette smoker. It is concluded that prolonged exposure to smoke allows for enhanced inhalation of radionuclides associated with smoke particles. Due to high radiotoxicity of alpha emitting radionuclides, and in particular of {sup 210}Po, the protection of respiratory tract of fire fighters is strongly recommended. - Highlights: • Natural radionuclides in vegetation are in low concentrations. • Forest fires release natural radionuclides from vegetation and concentrate them in inhalable ash particles. • Prolonged inhalation of smoke from forest fires gives rise enhanced radiation exposure of lungs especially due to polonium. • Respiratory protection of fire fighters and members of public is highly recommended for radioprotection reasons.

  14. Secondary Uranium-Phase Paragenesis and Incorporation of Radionuclides into Secondary Phase

    Energy Technology Data Exchange (ETDEWEB)

    R. Finch

    2001-06-05

    The purpose of this analysis/model report (AMR) is to assess the potential for uranium (U) (VI) compounds, formed during the oxidative corrosion of spent uranium-oxide (UO{sub 2}) fuels, to sequester certain radionuclides and, thereby, limit their release. The ''unsaturated drip tests'' being conducted at Argonne National Laboratory (ANL) provide the basis of this AMR (Table 1). The ANL drip tests on spent fuel are the only experiments on fuel corrosion from which solids have been analyzed for trace levels of radionuclides. Brief summaries are provided of the results from other selected corrosion and dissolution experiments on spent UO{sub 2} fuels, specifically those conducted under nominally oxidizing conditions. Discussions of the current understanding of thermodynamic and kinetic properties of U(VI) compounds is provided in order to outline the scientific basis for modeling precipitation and dissolution of potential radionuclide-bearing phases under repository-relevant conditions. Attachment I provides additional information on corrosion mechanisms and behaviors of radionuclides in the tests at ANL. Attachment II reviews occurrence, formation, and alteration (collectively known as paragenesis) of naturally occurring U(VI) minerals because natural mineral occurrences can be used to assess the possible long-term behaviors of U(VI) compounds formed in short-term laboratory experiments and to extrapolate experimental results to repository-relevant time scales. This AMR develops a model for calculating dissolved concentrations of radionuclides that are incorporated into U(VI) compounds, which is an alternative to models currently used in TSPA to calculate dissolved concentration limits for certain radionuclides. In particular, the model developed in this AMR applies to Np (neptunium) concentrations being controlled by solid uranyl oxyhydroxides that are known to contain trace levels of Np. The results of this AMR and the conceptual model

  15. Secondary Uranium-Phase Paragenesis and Incorporation of Radionuclides into Secondary Phases

    International Nuclear Information System (INIS)

    Finch, R.

    2001-01-01

    The purpose of this analysis/model report (AMR) is to assess the potential for uranium (U) (VI) compounds, formed during the oxidative corrosion of spent uranium-oxide (UO 2 ) fuels, to sequester certain radionuclides and, thereby, limit their release. The ''unsaturated drip tests'' being conducted at Argonne National Laboratory (ANL) provide the basis of this AMR (Table 1). The ANL drip tests on spent fuel are the only experiments on fuel corrosion from which solids have been analyzed for trace levels of radionuclides. Brief summaries are provided of the results from other selected corrosion and dissolution experiments on spent UO 2 fuels, specifically those conducted under nominally oxidizing conditions. Discussions of the current understanding of thermodynamic and kinetic properties of U(VI) compounds is provided in order to outline the scientific basis for modeling precipitation and dissolution of potential radionuclide-bearing phases under repository-relevant conditions. Attachment I provides additional information on corrosion mechanisms and behaviors of radionuclides in the tests at ANL. Attachment II reviews occurrence, formation, and alteration (collectively known as paragenesis) of naturally occurring U(VI) minerals because natural mineral occurrences can be used to assess the possible long-term behaviors of U(VI) compounds formed in short-term laboratory experiments and to extrapolate experimental results to repository-relevant time scales. This AMR develops a model for calculating dissolved concentrations of radionuclides that are incorporated into U(VI) compounds, which is an alternative to models currently used in TSPA to calculate dissolved concentration limits for certain radionuclides. In particular, the model developed in this AMR applies to Np (neptunium) concentrations being controlled by solid uranyl oxyhydroxides that are known to contain trace levels of Np. The results of this AMR and the conceptual model developed from it and presented in

  16. Movement of radionuclides from river to ground water in vicinity of location for nuclear power plant

    International Nuclear Information System (INIS)

    Knezevic, Lj.; Lazic, S.; Vukovic, Z.

    1984-01-01

    The possibility of ground water contamination caused by radionuclide from river water to which liquid effluents were released from a nuclear power station was estimated using one-dimensional transport model. This model is suitable for a homogeneous medium and takes into account hydraulic convection and dispersion as well as physical-chemical retardation for the various radionuclides. (author)

  17. 14C release from failed spent fuel containers

    International Nuclear Information System (INIS)

    Pescatore, C.

    1990-01-01

    Partially failed containers may provide a meaningful barrier to the release of gaseous radionuclides. A modeling approach is outlined and sample calculations are provided that show the effects on release due to a limited perforation area, to decreasing temperature, and to the partial occlusion of the perforated area by corrosion products. 8 refs., 2 tabs

  18. Release rates from waste packages in a salt repository

    International Nuclear Information System (INIS)

    Chambre, P.L.; Hwang, Y.; Lee, W.W.L.; Pigford, T.H.

    1987-06-01

    In this report we present estimates of radionuclide release rates from waste packages into salt. This conservative and bounding analysis shows that release rates from waste packages in salt are well below the US Nuclear Regulatory Commission's performance objectives for the engineered barrier system. 2 refs., 2 figs

  19. Resuspension and redistribution of radionuclides during grassland and forest fires in the Chernobyl exclusion zone: part II. Modeling the transport process

    International Nuclear Information System (INIS)

    Yoschenko, V.I.; Kashparov, V.A.; Levchuk, S.E.; Glukhovskiy, A.S.; Khomutinin, Yu.V.; Protsak, V.P.; Lundin, S.M.; Tschiersch, J.

    2006-01-01

    To predict parameters of radionuclide resuspension, transport and deposition during forest and grassland fires, several model modules were developed and adapted. Experimental data of controlled burning of prepared experimental plots in the Chernobyl exclusion zone have been used to evaluate the prognostic power of the models. The predicted trajectories and elevations of the plume match with those visually observed during the fire experiments in the grassland and forest sites. Experimentally determined parameters could be successfully used for the calculation of the initial plume parameters which provide the tools for the description of various fire scenarios and enable prognostic calculations. In summary, the model predicts a release of some per mille from the radionuclide inventory of the fuel material by the grassland fires. During the forest fire, up to 4% of 137 Cs and 9 Sr and up to 1% of the Pu isotopes can be released from the forest litter according to the model calculations. However, these results depend on the parameters of the fire events. In general, the modeling results are in good accordance with the experimental data. Therefore, the considered models were successfully validated and can be recommended for the assessment of the resuspension and redistribution of radionuclides during grassland and forest fires in contaminated territories

  20. Controlled release of diuron from an alginate-bentonite formulation: water release kinetics and soil mobility study.

    Science.gov (United States)

    Fernández-Pérez, M; Villafranca-Sánchez, M; González-Pradas, E; Flores-Céspedes, F

    1999-02-01

    The herbicide diuron was incorporated in alginate-based granules to obtain controlled release (CR) properties. The standard formulation (alginate-herbicide-water) was modified by the addition of different sorbents. The effect on diuron release rate caused by incorporation of natural and acid-treated bentonites in alginate formulation was studied by immersion of the granules in water under static conditions. The release of diuron was diffusion-controlled. The time taken for 50% release of active ingredient to be released into water, T(50), was calculated for the comparison of formulations. The addition of bentonite to the alginate-based formulation produced the higher T(50) values, indicating slower release of the diuron. The mobility of technical and formulated diuron was compared by using soil columns. The use of alginate-based CR formulations containing bentonite produced a less vertical distribution of the active ingredient as compared to the technical product and commercial formulation. Sorption capacities of the various soil constituents for diuron were also determined using batch experiments.

  1. The measurement of released radionuclides during TIG-Welding and Grinding

    Energy Technology Data Exchange (ETDEWEB)

    Reichelt, A.; Lehmann, K.-H. [Technical Inspection Agency of Southern Germany (TUEV Sueddeutschland), Subdepartment Environmental Radioactivity, Munich (Germany); Reineking, A. [Isotope Laboratory for Biological and Medical Research, Georg-August-University of Goettingen, Goettingen (Germany); Eder, E. [Government of Bavaria, State Ministry for State Development and Environmental Affairs, Munich (Germany)

    2000-05-01

    The radiological relevance of the TIG welding using thoriated tungsten electrodes has recently been proved by means of different studies. As a result of this the TUEV Sueddeutschland and the University of Goettingen have carried out special investigations concerning the release of radionuclides during TIG welding. The main emphasis of these investigations were the representativity of various sampling techniques, the influence of various parameters during welding as well as the determination of activity size distributions related to the aerodynamic diameter of the inhaled aerosols. The properties of the tungsten rods are improved through the addition of radioactive thorium. We investigated the radiation exposure by handling with thoriated tungsten welding rods. We investigated the different exposure pathways and determined the specific activity in dependence to the different types of welding rods. By carrying out surveys with the users, we determined the exposure pathways for the individual exposed persons: TIG - hand-welders', TIG 'machine-welders', labourers, other persons. We measured the activity concentration of the breathing air while welding, at grinding the electrodes and by staying in the rooms where usually it's welded. The size distribution of the aerosol-attached activity was determined with several kinds of impactors. The main emphasis was the comparison of the different sampling systems at the measuring of the activity concentration of the breathing air. Selective sampling by impactors: {center_dot} Berner-impactor, stationary {center_dot} Sierra-impactor, stationary {center_dot} Anderson-Imcaktor, stationary {center_dot} Marple-impactor, personal sampler Aerosol sampling by air samplers {center_dot} 5 personal air sampler {center_dot} 2 stationary sampler, ring face {center_dot} 2 stationary sampler, open face Rn-220-Measurements {center_dot} Thoron-monitor Determination of activitys on measuring filters {center_dot} alpha

  2. Radionuclide transfer to fruit in the IAEA TRS No. 472

    Directory of Open Access Journals (Sweden)

    Giosuè S.

    2012-04-01

    Full Text Available This paper describes the approach taken to present the information on fruits in the IAEA report TRS No. 472, supported by the IAEA-TECDOC-1616, which describes the key transfer processes, concepts and conceptual models regarded as important for dose assessment, as well as relevant parameters for modelling radionuclide transfer in fruits. Information relate to fruit plants grown in agricultural ecosystems of temperate regions. The relative significance of each pathway after release of radionuclides depends upon the radionuclide, the kind of crop, the stage of plant development and the season at time of deposition. Fruit intended as a component of the human diet is borne by plants that are heterogeneous in habits, and morphological and physiological traits. Information on radionuclides in fruit systems has therefore been rationalised by characterising plants in three groups: woody trees, shrubs, and herbaceous plants. Parameter values have been collected from open literature, conference proceedings, institutional reports, books and international databases. Data on root uptake are reported as transfer factor values related to fresh weight, being consumption data for fruits usually given in fresh weight.

  3. Radionuclide sources in the Barents and Kara Seas

    International Nuclear Information System (INIS)

    Smith, J.N.; Ellis, K.M.; Forman, S.; Polyak, L.; Ivanov, G.; Matishov, D.; Kilius, L.

    1995-01-01

    A study of radionuclide distributions in the Barents Sea sediments was carried out in 1992. The conclusions of the study are as follows: 1) Elevated levels of artificial radionuclides as great as 15,000 Bq/kg for 239,240 Pu, 250 Bq/kg for 137 Cs and 100 Bq/kg for 60 Co were measured in sediments in Chermaya Bay which have been contaminated by several nuclear tests conducted in the 1950s. 2) Sediment-depth distributions of 239,240 Pu and other artificial radionuclides are consistent with results from biodiffusion models that are constrained by 210 Pb sediment-depth distributions. These results indicate that sedimentation rates in Chernaya Bay are low ( 249 Pu/ 239 Pu and 241 Pu/ 239 Pu atom ratios of 0.030 and 0.0012, respectively and a 241 Am/ 239,240 Pu activity ratio of 0.05 (compared to 0.3 in fallout) which provides a method for tracking its dispersion over distances of 100 km into the Barents Sea. 4) Artificial radionuclide levels in sediments and seawater near a sunken barge loaded with radioactive wastes in the Novaya Zemlya trough are similar to background fallout levels in the Kara Sea and provide little evidence for the release of radioactive contaminants from the dumpsite. 7 refs., 4 figs

  4. Radioactive materials released from nuclear power plants (1976)

    International Nuclear Information System (INIS)

    Decker, T.R.

    1978-11-01

    Releases of radioactive materials in airborne and liquid effluents from commercial light water reactors during 1976 have been compiled and reported. Data on solid waste shipments as well as selected operating information have been included. This report supplements earlier annual reports issued by the former Atomic Energy Commission and the Nuclear Regulatory Commission. The 1976 release data are compared with previous year releases in tabular form. Data covering specific radionuclides are summarized

  5. Methods of separating short half-life radionuclides from a mixture of radionuclides

    International Nuclear Information System (INIS)

    Bray, L.A.; Ryan, J.L.

    1998-01-01

    The present invention is a method of obtaining a radionuclide product selected from the group consisting of 223 Ra and 225 Ac, from a radionuclide ''cow'' of 227 Ac or 229 Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ''cow'' forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ''cow'' from at least one radionuclide daughter; (d) insuring that the at least one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ''cow''. In one embodiment the radionuclide ''cow'' is the 227 Ac, the at least one daughter radionuclide is a 227 Th and the product radionuclide is the 223 Ra and the first nitrate form ion exchange column passes the 227 Ac and retains the 227 Th. In another embodiment the radionuclide ''cow'' is the 229 Th, the at least one daughter radionuclide is a 225 Ra and said product radionuclide is the 225 Ac and the 225 Ac and nitrate form ion exchange column retains the 229 Th and passes the 225 Ra/Ac. 8 figs

  6. Release modes and processes relevant to source-term calculations at Yucca Mountain

    International Nuclear Information System (INIS)

    Apted, M.J.

    1994-01-01

    The feasibility of permanent disposal of radioactive high-level waste (HLW) in repositories located in deep geologic formations is being studied world-wide. The most credible release pathway is interaction between groundwater and nuclear waste forms, followed by migration of radionuclide-bearing groundwater to the accessible environment. Under hydrologically unsaturated conditions, vapor transport of volatile radionuclides is also possible. The near-field encompasses the waste packages composed of engineered barriers (e.g. man-made materials, such as vitrified waste forms, corrosion-resistant containers), while the far-field includes the natural barriers (e.g. host rock, hydrologic setting). Taken together, these two subsystems define a series of multiple, redundant barriers that act to assure the safe isolation of nuclear waste. In the U.S., the Department of energy (DOE) is investigating the feasibility of safe, long-term disposal of high-level nuclear waste at the Yucca Mountain site in Nevada. The proposed repository horizon is located in non-welded tuffs within the unsaturated zone (i.e. above the water table) at Yucca Mountain. The purpose of this paper is to describe the source-term models for radionuclide release from waste packages at Yucca Mountain site. The first section describes the conceptual release modes that are relevant for this site and waste package design, based on a consideration of the performance of currently proposed engineered barriers under expected and unexpected conditions. No attempt is made to asses the reasonableness nor probability of occurrence for any specific release mode. The following section reviews the waste-form characteristics that are required to model and constrain the release of radionuclides from the waste package. The next section present mathematical models for the conceptual release modes, selected from those that have been implemented into a probabilistic total system assessment code developed for the Electric Power

  7. Review of the ecological parameters of radionuclide turnover in vertebrate food chains

    International Nuclear Information System (INIS)

    Kitchings, T.; DiGregorio, D.; Van Voris, P.

    1975-01-01

    Ecological studies of radionuclides in the environment have a long tradition in developing the capability to identify and predict movement and concentration of nuclides in agronomic food chains leading to man. Food chain pathways and transfer coefficients for the non-agronomic portions of natural and managed ecosystems characteristic of affected habitats adjacent to nuclear facilities have not been adequately characterized to establish reliable dispersion models for radionuclide releases. This information is necessary in order to assess the impact that such installations will have on the biota of natural ecosystems. Since food chains are the major processes transferring elements from one trophic level to another in terrestrial ecosystems, information is needed on the food-chain transfer pathways, bioconcentration by each trophic component, and turnover rates by receptor organisms. These data are prerequisite inputs for food-chain transport models and can be correlated with species characteristics (e.g., body weight and feeding habitats), to provide indices for predictive dispersion calculations. Application of these models for radionuclide transfer can aid in the assessment of radioactive releases from nuclear reactor facilities to terrestrial non-agronomic food chains. (U.S.)

  8. HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ivana Vukanac

    2012-09-01

    Full Text Available Artificial radionuclides are product of different human activities and their presence in the environment is negative side effect of civilization progress. They have been spread in the environment by events such as nuclear weapon tests, nuclear accidents and by deliberate and negligent discharge of radioactive waste from nuclear and other installation. Once released in to the nature, the artificial radionuclides start to circle in the same manner as naturally occurring ones, and finally they fall out from air and water onto the ground and build into the foodstuff and drinking water resulting in radiation doses to human beings. The short overview of presence of artificial radioactivity in human environment and its impact on human life is presented in this paper.

  9. HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ivana Vukanac

    2012-09-01

    Full Text Available Artificial radionuclides are product of different human activities and their presence in the environment is negative side effect of civilization progress. They have been spread in the environment by events such as nuclear weapon tests, nuclear accidents and by deliberate and negligent discharge of radioactive waste from nuclear and other installation. Once released in to the nature, the artificial radionuclides start to circle in the same manner as naturally occurring ones, and finally they fall out from air and water onto the ground and build into the foodstuff and drinking water resulting in radiation doses to human beings. The short overview of presence of artificial radioactivity in human environment and its impact on human life is presented in this paper

  10. Building Adjustable Pre-storm Reservoir Flood-control Release Rules

    Science.gov (United States)

    Yang, Shun-Nien; Chang, Li-Chiu; Chang, Fi-John; Hsieh, Cheng-Daw

    2017-04-01

    Typhoons hit Taiwan several times every year, which could cause serious flood disasters. Because mountainous terrains and steep landforms can rapidly accelerate the speed of flood flow during typhoon events, rivers cannot be a stable source of water supply. Reservoirs become the most effective floodwater storage facilities for alleviating flood damages in Taiwan. The pre-storm flood-control release can significantly increase reservoir storage capacity available to store floodwaters for reducing downstream flood damage, while the uncertainties of total forecasted rainfalls are very high in different stages of an oncoming typhoon, which may cause the risk of water shortage in the future. This study proposes adjustable pre-storm reservoir flood-control release rules in three designed operating stages with various hydrological conditions in the Feitsui Reservoir, a pivot reservoir for water supply to Taipei metropolitan in Taiwan, not only to reduce the risk of reservoir flood control and downstream flooding but also to consider water supply. The three operating stages before an oncoming typhoon are defined upon the timings when: (1) typhoon news is issued (3-7days before typhoon hit); (2) the sea warning is issued (2-4 days before typhoon hit); and (3) the land warning is issued (1-2 days before typhoon hit). We simulate 95 historical typhoon events with 3000 initial water levels and build some pre-storm flood-control release rules to adjust the amount of pre-release based on the total forecasted rainfalls at different operating stages. A great number of simulations (68.4 millions) are conducted to extract their major consequences and then build the adjustable pre-storm reservoir flood-control release rules. Accordingly, given a total forecasted rainfall and a water level, reservoir decision makers can easily identify the corresponding rule to tell the amount of pre-release in any stage. The results show that the proposed adjustable pre-release rules can effectively

  11. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes [DHI, Hoersholm (Denmark)

    2010-06-15

    -stationary equilibrium within the model area. The coupled ecosystem and radionuclide models were used to simulate present conditions, i.e. 2020 AD. Six radionuclides were modelled explicitly in addition to C-14. They represent a wide range of accumulation potentials and partition coefficients (K{sub d}, distribution of radionuclides between water, sediment and biota). The ecosystem and associated radionuclide model include a detailed sediment module where radionuclides can be bound by adsorption to the organic and inorganic fractions, be precipitated, be transported by resuspension and later deposited at larger depths. With the exception of radionuclides with very low particle affinity, such as Cl-35, the majority of radionuclides released in basins where they were introduced via groundwater flow remained in the sediments even after a simulation period of eight years. The spread of radionuclides with high partition coefficients for sediments from areas with groundwater flow takes place by sediment resuspension and subsequent transport and sedimentation. In the case of radionuclides with lower partition coefficients, release from the sediments to the water column followed by transport of dissolved radionuclides by currents plays a larger role. A significant result of the modelling was the quantification of the seasonal and spatial variation in radionuclide accumulation and in bioconcentration factors (BCFs) with spatial variation of BCFs often ranging 2 to 3 orders of magnitude. This variation was dominated by spatial differences in concentrations of radionuclides in water. In basins where radionuclides were introduced by groundwater flow, BCFs were typically 2-3 orders of magnitude lower than in deep basins without radionuclide release in the groundwater. In phytoplankton and grazers, bioconcentration factors (BCFs) scaled linearly to partition coefficients (Kd), underlining the fact that adsorption is an important process for radionuclide accumulation in the lower parts of the food web

  12. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes (DHI, Hoersholm (Denmark))

    2010-06-15

    quasi-stationary equilibrium within the model area. The coupled ecosystem and radionuclide models were used to simulate present conditions, i.e. 2020 AD. Six radionuclides were modelled explicitly in addition to C-14. They represent a wide range of accumulation potentials and partition coefficients (K{sub d}, distribution of radionuclides between water, sediment and biota). The ecosystem and associated radionuclide model include a detailed sediment module where radionuclides can be bound by adsorption to the organic and inorganic fractions, be precipitated, be transported by resuspension and later deposited at larger depths. With the exception of radionuclides with very low particle affinity, such as Cl-35, the majority of radionuclides released in basins where they were introduced via groundwater flow remained in the sediments even after a simulation period of eight years. The spread of radionuclides with high partition coefficients for sediments from areas with groundwater flow takes place by sediment resuspension and subsequent transport and sedimentation. In the case of radionuclides with lower partition coefficients, release from the sediments to the water column followed by transport of dissolved radionuclides by currents plays a larger role. A significant result of the modelling was the quantification of the seasonal and spatial variation in radionuclide accumulation and in bioconcentration factors (BCFs) with spatial variation of BCFs often ranging 2 to 3 orders of magnitude. This variation was dominated by spatial differences in concentrations of radionuclides in water. In basins where radionuclides were introduced by groundwater flow, BCFs were typically 2-3 orders of magnitude lower than in deep basins without radionuclide release in the groundwater. In phytoplankton and grazers, bioconcentration factors (BCFs) scaled linearly to partition coefficients (Kd), underlining the fact that adsorption is an important process for radionuclide accumulation in the

  13. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    International Nuclear Information System (INIS)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes

    2010-06-01

    -stationary equilibrium within the model area. The coupled ecosystem and radionuclide models were used to simulate present conditions, i.e. 2020 AD. Six radionuclides were modelled explicitly in addition to C-14. They represent a wide range of accumulation potentials and partition coefficients (K d , distribution of radionuclides between water, sediment and biota). The ecosystem and associated radionuclide model include a detailed sediment module where radionuclides can be bound by adsorption to the organic and inorganic fractions, be precipitated, be transported by resuspension and later deposited at larger depths. With the exception of radionuclides with very low particle affinity, such as Cl-35, the majority of radionuclides released in basins where they were introduced via groundwater flow remained in the sediments even after a simulation period of eight years. The spread of radionuclides with high partition coefficients for sediments from areas with groundwater flow takes place by sediment resuspension and subsequent transport and sedimentation. In the case of radionuclides with lower partition coefficients, release from the sediments to the water column followed by transport of dissolved radionuclides by currents plays a larger role. A significant result of the modelling was the quantification of the seasonal and spatial variation in radionuclide accumulation and in bioconcentration factors (BCFs) with spatial variation of BCFs often ranging 2 to 3 orders of magnitude. This variation was dominated by spatial differences in concentrations of radionuclides in water. In basins where radionuclides were introduced by groundwater flow, BCFs were typically 2-3 orders of magnitude lower than in deep basins without radionuclide release in the groundwater. In phytoplankton and grazers, bioconcentration factors (BCFs) scaled linearly to partition coefficients (Kd), underlining the fact that adsorption is an important process for radionuclide accumulation in the lower parts of the food web

  14. Development of scaling factor prediction method for radionuclide composition in low-level radioactive waste

    International Nuclear Information System (INIS)

    Park, Jin Beak

    1995-02-01

    Low-level radioactive waste management require the knowledge of the natures and quantities of radionuclides in the immobilized or packaged waste. U. S. NRC rules require programs that measure the concentrations of all relevant nuclides either directly or indirectly by relating difficult-to-measure radionuclides to other easy-to-measure radionuclides with application of scaling factors. Scaling factors previously developed through statistical approach can give only generic ones and have many difficult problem about sampling procedures. Generic scaling factors can not take into account for plant operation history. In this study, a method to predict plant-specific and operational history dependent scaling factors is developed. Realistic and detailed approach are taken to find scaling factors at reactor coolant. This approach begin with fission product release mechanisms and fundamental release properties of fuel-source nuclide such as fission product and transuranic nuclide. Scaling factors at various waste streams are derived from the predicted reactor coolant scaling factors with the aid of radionuclide retention and build up model. This model make use of radioactive material balance within the radioactive waste processing systems. Scaling factors at reactor coolant and waste streams which can include the effects of plant operation history have been developed according to input parameters of plant operation history

  15. Human radiation dose resulting from forests contaminated by radionuclides: generic model and applications to the Chernobyl ecosystems

    International Nuclear Information System (INIS)

    Linkov, I.; Harvard Univ., Cambridge, MA; Schell, W.R.

    1996-01-01

    Forest ecosystems have been found to contribute significantly to the human radiation dose in the intermediate and long teens following radionuclide releases. Evaluation of the internal and external radiation dose for these critical population groups requires knowledge of radionuclide transport processes in forest ecosystems, as well as the extent of forest utilization by these populations. The high complexity of the problem requires the use of models to define and analyze the properties of the forest as well as to evaluate the ecosystem response to possible human intervention. A generic FORESTPATH model is used to calculate the internal and external radiation doses for different critical groups of consumers at different times following radionuclide release. The model is tested using the information available for contaminated forests in Belarus. Uncertainty of the model predictions are estimated by means of Monte-Carlo simulations. (author)

  16. The effects of culinary preparation on radionuclide levels in vegetable foodstuffs

    International Nuclear Information System (INIS)

    Wilkins, B.T.; Bradley, E.J.; Dodd, N.J.

    1987-01-01

    Vegetables contaminated by fall-out from the Chernobyl nuclear reactor accident have been used to investigate how simple culinary methods can affect the levels of various radionuclides in the portion consumed by man. Only γ ray emitting radionuclides were investigated. Those parts of vegetables normally considered inedible, for example coarse outer leaves, foliage or roots, can account for between 50% and 97% of the total radionuclide content. Washing of the edible parts of vegetables can reduce the levels still further, although the efficacy is dependent on both the radionuclide and the vegetable type. These normal domestic procedures can reduce intakes of recently deposited radionuclides on vegetables by about an order of magnitude. The results have implications for the scope of monitoring programmes that might follow any future accidental release. They also reinforce very strongly the requirement for measurements on edible parts rather than whole samples as a direct input to dose evaluation. These results further suggest that there is no need to revise the general assumptions made in accident consequence models regarding losses of activity between harvest and consumption. However, more rigorous assessments of dose should take account of vegetable type and probable means of preparation. (author)

  17. Simulation of atmospheric dispersion of radionuclides using an Eulerian-Lagrangian modelling system.

    Science.gov (United States)

    Basit, Abdul; Espinosa, Francisco; Avila, Ruben; Raza, S; Irfan, N

    2008-12-01

    In this paper we present an atmospheric dispersion scenario for a proposed nuclear power plant in Pakistan involving the hypothetical accidental release of radionuclides. For this, a concept involving a Lagrangian stochastic particle model (LSPM) coupled with an Eulerian regional atmospheric modelling system (RAMS) is used. The atmospheric turbulent dispersion of radionuclides (represented by non-buoyant particles/neutral traces) in the LSPM is modelled by applying non-homogeneous turbulence conditions. The mean wind velocities governed by the topography of the region and the surface fluxes of momentum and heat are calculated by the RAMS code. A moving least squares (MLS) technique is introduced to calculate the concentration of radionuclides at ground level. The numerically calculated vertical profiles of wind velocity and temperature are compared with observed data. The results obtained demonstrate that in regions of complex terrain it is not sufficient to model the atmospheric dispersion of particles using a straight-line Gaussian plume model, and that by utilising a Lagrangian stochastic particle model and regional atmospheric modelling system a much more realistic estimation of the dispersion in such a hypothetical scenario was ascertained. The particle dispersion results for a 12 h ground release show that a triangular area of about 400 km(2) situated in the north-west quadrant of release is under radiological threat. The particle distribution shows that the use of a Gaussian plume model (GPM) in such situations will yield quite misleading results.

  18. The effects of radionuclides in the atmosphere on weather, climate and environment

    International Nuclear Information System (INIS)

    Jager, D. de.

    1992-10-01

    A literature study on the effects of the released radionuclides in the atmosphere on weather, climate and environment are reported. In this report a science outlook of these effects is presented. The emissions generated by the electricity are the central issue. For the global effects the released krypton-85 (half-life time 10,78 years) which are caused by reprocessing factories would take an important role, but for local effects the releasing of short-living isotopes as xenon-133 and xenon-135 produced by nuclear reactors and radon-222 produced by mining activities must be taken into account. The production, emission and distribution of these related important isotopes are discussed, just like air-electric circuits (global), the chemistry of the atmosphere (local) and the consequences of it for the weather, climate and environment on earth. Radionuclides could affect on the development of the thunderstorm, rainfall, cloud formation, air dampness, acid- and aerosol formations and also indirect, for example, for the greenhouse effect and acid rainfall. (author). 133 refs., 22 figs., 11 tabs

  19. Methods of separating short half-life radionuclides from a mixture of radionuclides

    Science.gov (United States)

    Bray, Lane A.; Ryan, Jack L.

    1998-01-01

    The present invention is a method of obtaining a radionuclide product selected from the group consisting of .sup.223 Ra and .sup.225 Ac, from a radionuclide "cow" of .sup.227 Ac or .sup.229 Th respectively. The method comprises the steps of a) permitting ingrowth of at least one radionuclide daughter from said radionuclide "cow" forming an ingrown mixture; b) insuring that the ingrown mixture is a nitric acid ingrown mixture; c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the "cow" from at least one radionuclide daughter; d) insuring that the at least one radionuclide daughter contains the radionuclide product; e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and f) recycling the at least one radionuclide daughter by adding it to the "cow". In one embodiment the radionuclide "cow" is the .sup.227 Ac, the at least one daughter radionuclide is a .sup.227 Th and the product radionuclide is the .sup.223 Ra and the first nitrate form ion exchange column passes the .sup.227 Ac and retains the .sup.227 Th. In another embodiment the radionuclide "cow"is the .sup.229 Th, the at least one daughter radionuclide is a .sup.225 Ra and said product radionuclide is the .sup.225 Ac and the .sup.225 Ac and nitrate form ion exchange column retains the .sup.229 Th and passes the .sup.225 Ra/Ac.

  20. Silica colloids and their effect on radionuclide sorption. A literature review

    International Nuclear Information System (INIS)

    Hoelttae, P.; Hakanen, M.

    2008-05-01

    Silica sol, commercial colloidal silica manufactured by Eka Chemicals in Bohus, Sweden is a promising inorganic grout material for sealing small fractures in low permeable rock. This literature review collects information about the use of silica sol as an injection grout material, the properties of inorganic, especially silica colloids, colloid contents in granitic groundwater conditions, essential characterization methods and colloid-mediated transport of radionuclides. Objective was to evaluate the release and mobility of silica sol colloids, the effect of the groundwater conditions, the amount of colloids compared with natural colloids in Olkiluoto conditions, radionuclide sorption on colloids and their contribution to radionuclide transport. Silica sol seems to be a feasible material to seal fractures with an aperture as small as 10 μm in low permeable rock. The silica sol gel is sufficiently stable to limit to water ingress during the operational phase, the requirement that the pH should be below 11 is fulfilled and the compatibility with Engineered Barrier System (EBS) materials is expected to be good. No significant influence on the bentonite properties caused by the silica sol is expected when calcium chloride is used as an accelerator but the influence of sodium chloride has not been examined. No significant release of colloids is expected under prevailing groundwater conditions. The long-term (100 y) stability of silica sol gel has not yet been clearly demonstrated and a long-term release of silica colloids cannot be excluded. The question is the amount of colloids, how mobile they are and the influence of possible glacial melt waters. The bentonite buffer used in the EBS system is assumed to be a potential source of colloids. In a study in Olkiluoto, bentonite colloids were found only in low salinity groundwater. In general, low salinity water (total dissolved solids -1 ) favours colloid stability and bentonite colloids can remain stable over long

  1. Release of segregated nuclides from spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.H.; Tait, J.C. [Atomic Energy Canada Ltd., Pinawa, MB (Canada). Whiteshell Laboratories

    1997-10-01

    The potential release of fission and activation products from spent nuclear fuel into groundwater after container failure in the Swedish deep repository is discussed. Data from studies of fission gas release from representative Swedish BWR fuel are used to estimate the average fission gas release for the spent fuel population. Information from a variety of leaching studies on LWR and CANDU fuel are then reviewed as a basis for estimating the fraction of the inventory of key radionuclides that could be released preferentially (the Instant Release Fraction of IRF) upon failure of the fuel cladding. The uncertainties associated with these estimates are discussed. 33 refs, 6 figs, 3 tabs.

  2. Characterization of a Planetary Boundary Layer model to evaluate radionuclides releases in nuclear installations; Caracterizacao de um modelo de camada limite planetaria para avaliar liberacoes de radionuclideos em instalacoes nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Molnary, Leslie de

    1993-07-01

    A two layer bulk model is used to simulate numerically the time and spatial evolution of concentration of radionuclides in the Planetary Boundary Layer (PBL) for convective and stable conditions. In this model, the closure hypothesis are based on the integrated version of the Turbulent Kinetics Energy (TKE) equation (Smeda,1979). This type of model was adopted here because it is numerically simple to be applied operationally in routine and emergency support systems of atmospheric releases at nuclear power plants, and the hypothesis of the efficiency of the vertical mixing seems to be physically reasonable to simulated PBL evolution for high wind conditions and stable conditions in Subtropical latitudes regions. In order to validate the model to the nuclear power plants of the Centro Experimental Aramar (CEA), located in Ipero, State of Sao Paulo, Brazil, numerical simulations were carried out with initial and boundary conditions based on vertical profiles of temperature and horizontal wind speed and direction obtained from tethered balloon soundings, synoptic charts at 850 hPa and surface observations. Comparisons between a 24 hour long numerical simulation and observations indicate that the model is capable of reproduce the diurnal evolution of temperature and horizontal wind during the convective regime. During stable conditions, the slab model was able to simulate the intensity of the surface inversion as a difference between the mixed layer and surface temperatures. The simulated mixed layer height matches with observations during the convective and stable regime. A daytime release of radionuclides was simulated for CEA region and the results indicated that the maximum relative concentration reaches a distance about 15 Km in 1 hour, varing from 100 times background at the moment of the release to 15 times the background. For night releases, the maximum concentration reaches the same distance in 45 minutes, varing from 100 to 30 times the background values

  3. Twenty-five-year study of radionuclides in the Susquehanna river via periphyton biomonitors.

    Science.gov (United States)

    Patrick, Ruth; Palms, John; Kreeger, Danielle; Harris, Charles

    2007-01-01

    This 25-y study monitored aquatic and terrestrial gamma-ray-emitting radionuclide levels near a nuclear power plant. It is the only known, long-term environmental survey of its kind. It was conducted neither by a utility owner, nor by a government agency, but rather by a private, environmental research institution. Compared to dozens of other flora and fauna, periphyton was found to be the best indicator to biomonitor the Susquehanna River, which runs near PPL Susquehanna's nuclear plant. Sampling began in 1979 before the first plant start-up and continued for the next 24 years. Monitoring began two months after the Three Mile Island accident of 28 March 1979 and includes Three Mile Island area measurements. Ongoing measurements detected fallout from Chernobyl in 1986, as well as I not released from PPL Susquehanna. Although this paper concentrates on radionuclides found in periphyton, the scope of the entire environmental program includes a wide variety of aquatic and land-based plants, animals, and inorganic matter. Other species and matter studied were fish, mussels, snails, crayfish, insects, humus, mushrooms, lichens, squirrels, deer, cabbage, tomatoes, coarse and flocculated sediment, and more. Results show periphyton works well for detection of radionuclide activity, even in concentrations less than 100 Bq kg (picocuries per gram amounts). Data indicate that PPL Susquehanna's radionuclide releases have had no known environmental or human health impact.

  4. Release of alpha emitters into the environment by Nuclear Industries of Brazil in Resende, RJ

    International Nuclear Information System (INIS)

    Pereira, Wagner S.; Kelecom, Alphonse; Santos, Rodney; Santos, Maisa F.M.; Torres, Vinicius R.M.; Rodrigues, Jéssica J.S.; Universidade Veiga de Almeida; Universidade Federal Fluminense

    2017-01-01

    The Nuclear Industries of Brazil operates in the field of nuclear energy and has a monopoly on mining and manufacturing the nuclear fuel element in Brazil. The Nuclear Fuel Factory is also responsible for the reconversion process, the manufacture of the pellets and the assembly of the fuel element. Once there is a possibility of particulate material generation during the reconversion processes and the manufacture of pellets, a method of collective protection of the worker was established, which includes a system of air exhaustion of the factory area, with the capacity to renew the indoor air six times per hour. As a control measure, there is a system of automatic detection of the release of radionuclides in the chimney that monitors and calculates the released values. Through the dose calculation model established by the National Commission for Nuclear Energy the release limit is fixed at 1.2∙ 10"7Bq.y"-"1 of alpha emitters by FCN. The present work aims to evaluate the alpha radionuclides released by FCN, in terms of total release (Bq) and Activity Concentration (AC, mBq∙m"-"3). In 2016 it was released 4.14∙10"6Bq.y"-"1, which means an average of 3.45∙10"5Bq.month"-"1. The largest mean for AC was 4.03 mBq∙m"-"3. The release data was almost an order of magnitude lower than the annual release limit, proving the suitability of the atmospheric effluents to the licensing requirements. The largest magnitudes of the two variables (AC and release) were observed in August while the smallest ones, in January. (author)

  5. Release of alpha emitters into the environment by Nuclear Industries of Brazil in Resende, RJ

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner S.; Kelecom, Alphonse; Santos, Rodney; Santos, Maisa F.M.; Torres, Vinicius R.M.; Rodrigues, Jéssica J.S., E-mail: comap@inb.gov.br, E-mail: pereiraws@gmail.com, E-mail: lararapls@hotmail.com [Indústrias Nucleares do Brasil (COMAP.N/FCN/INB), Resende RJ (Brazil). Fábrica de Combustível Nuclear. Coordenação de Meio Ambiente e Proteção Radiológica Ambiental; Universidade Veiga de Almeida (UVA), Rio de Janeiro, RJ (Brazil); Universidade Federal Fluminense (LARARA-PLS/UFF), Niterói, RJ (Brazil). Laboratório de Radiobiologia e Radiometria

    2017-07-01

    The Nuclear Industries of Brazil operates in the field of nuclear energy and has a monopoly on mining and manufacturing the nuclear fuel element in Brazil. The Nuclear Fuel Factory is also responsible for the reconversion process, the manufacture of the pellets and the assembly of the fuel element. Once there is a possibility of particulate material generation during the reconversion processes and the manufacture of pellets, a method of collective protection of the worker was established, which includes a system of air exhaustion of the factory area, with the capacity to renew the indoor air six times per hour. As a control measure, there is a system of automatic detection of the release of radionuclides in the chimney that monitors and calculates the released values. Through the dose calculation model established by the National Commission for Nuclear Energy the release limit is fixed at 1.2∙ 10{sup 7}Bq.y{sup -1} of alpha emitters by FCN. The present work aims to evaluate the alpha radionuclides released by FCN, in terms of total release (Bq) and Activity Concentration (AC, mBq∙m{sup -3}). In 2016 it was released 4.14∙10{sup 6}Bq.y{sup -1}, which means an average of 3.45∙10{sup 5}Bq.month{sup -1}. The largest mean for AC was 4.03 mBq∙m{sup -3}. The release data was almost an order of magnitude lower than the annual release limit, proving the suitability of the atmospheric effluents to the licensing requirements. The largest magnitudes of the two variables (AC and release) were observed in August while the smallest ones, in January. (author)

  6. Distribution of natural radionuclides in soil around Sultan Azlan Shah Coal-Fired Power Plant at Manjung, Perak

    International Nuclear Information System (INIS)

    Zaini Hamzah; Fetri Zainal; Ahmad Saat; Abdul Khalik Wood

    2013-01-01

    Full-text: A radionuclide is an atom with an unstable nucleus which is created by excess energy. This radionuclide will undergo radioactive decay where gamma ray or sub atomic particles are released making them radioactive which can be harmful if the safe level is exceeded. This study was carried out in Manjung, Perak near Sultan Azlan Shah coal-fired power plant. Coal combustion from power plant generates emissions of potentially toxic radionuclides besides major pollutants which are particulates, sulphur and nitrogen oxides. It is noted that emission of particulates, sulphur and nitrogen oxides are strictly control. Soil is one of the most important media for plant to growth however soil is subject to contamination and its quality must be protected. The concentration of natural radionuclides in soil can be affected from coal combustion process from power plant in order to generate electricity. In this study, natural radionuclides concentration such as 238 U and 232 Th concentration in soil at nine points around this power plant were determined to assess radioactivity level and the possible radiation hazard to local population that residence in that area will be carried out in future study. Concentrations of natural radionuclides have been determined by using Energy Dispersive X-ray Fluorescence (EDXRF) technique. The concentration of 238 U in the area were in the ranged between 3.42 mg/ kg to 7.59 mg/ kg. While the concentration of 232 Th ranged from 12.19 mg/ kg to 21.67 mg/ kg respectively. (author)

  7. Radionuclide Migration through Sediment and Concrete: 16 Years of Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Golovich, Elizabeth C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mattigod, Shas V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snyder, Michelle MV [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Powers, Laura [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Whyatt, Greg A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wellman, Dawn M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-11-01

    The Waste Management Project provides safe, compliant, and cost-effective waste management services for the Hanford Site and the U.S. Department of Energy (DOE) complex. Part of these services includes safe disposal of low-level waste and mixed low-level waste at the Hanford Low-Level Waste Burial Grounds in accordance with the requirements of DOE Order 435.1, Radioactive Waste Management. To partially satisfy these requirements, performance assessment analyses were completed and approved. DOE Order 435.1 also requires continuing data collection to increase confidence in the critical assumptions used in these analyses to characterize the operational features of the disposal facility that are relied on to satisfy the performance objectives identified in the order. Cement-based solidification and stabilization is considered for hazardous waste disposal because it is easily done and cost-efficient. One critical assumption is that concrete will be used as a waste form or container material at the Hanford Site to control and minimize the release of radionuclide constituents in waste into the surrounding environment. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The radionuclides iodine-129, selenium-75, technetium-99, and uranium-238 have been identified as long-term dose contributors (Mann et al. 2001; Wood et al. 1995). Because of their anionic nature in aqueous solutions, these constituents of potential concern may be released from the encased concrete by mass flow and/or diffusion and migrate into the surrounding subsurface environment (Serne et al. 1989; 1992; 1993a, b; 1995). Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. Each of the

  8. The transfer of radionuclides from saltmarsh vegetation to sheep tissues and milk

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N.A. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)], E-mail: nab@ceh.ac.uk; Howard, B.J. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Mayes, R.W.; Lamb, C.S. [Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom)

    2007-11-15

    Radionuclides released into the Irish Sea by the Sellafield reprocessing plant are deposited onto tide-washed pastures along the western coast of the United Kingdom. Many of these pastures are grazed by sheep or cattle. This paper describes a controlled feeding study, in which saltmarsh vegetation harvested from close to the Sellafield plant, was fed to lambs and adult female sheep for a period of 8 weeks. Activity concentrations of {sup 60}Co, {sup 95}Nb, {sup 106}Ru, {sup 134}Cs, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu and {sup 241}Am were determined in edible tissues and transfer parameters estimated. The activity concentrations of some of the radionuclides will not have been in equilibrium with those in the diet. Nevertheless, the study was reasonably realistic in terms of agricultural management as the period of the study was similar to that for which lambs graze on the saltmarshes. A field study to determine the activity concentrations of {sup 137}Cs and {sup 239,240}Pu in the milk of ewes grazing a saltmarsh close to Sellafield is also described.

  9. Development of COLLAGE 3; Role for colloids in the transport of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Klos, Richard (Aleksandria Sciences, Sheffield (United Kingdom)); Bath, Adrian (Intellisci Ltd., Loughborough (United Kingdom))

    2010-03-15

    The issue of colloid-facilitated radionuclide transport (CFRT) was last addressed by the Swedish nuclear regulators in 2001 - 2002. SKI had commissioned the Collage code with subsequent development as Collage 2. This code was employed to investigate the potential role for colloids to have been involved in the transport of radionuclides at the Nevada Test Site and to examine the implications for CFRT in the Swedish disposal programme. It was concluded that colloids could not be ruled out as a mechanism for rapid transport and early release from the geosphere. Recently the 'bentonite erosion scenario' has become of concern. In it the generation of large quantities of bentonite colloids in fractures as a result of fresh water ingress at repository depth is possible. Potentially, these could carry radiologically significant quantities of radionuclides to an early release to the surface system. The objectives of this work are to update the knowledge of colloid-facilitated radionuclide transport through a fractured geosphere and to provide review capability within the SSM. Recent developments in CFRT (reviewed here) indicate that additional parameters needed to be added to the existing Collage 2 plus code in order to adequately represent colloid transport in fractures. This report looks at modifications to the model and discusses the implications of the implementation of the new processes. Authors conclude that the process of colloid filtration is an important mitigating mechanism. A new code - Collage 3 - is demonstrated and suggestions for further work are given

  10. Redox phenomena controlling systems - a 7. framework programme collaborative project (2008-2012)

    International Nuclear Information System (INIS)

    2013-01-01

    The objective of this EURATOM collaborative project is to understand Redox phenomena controlling the long-term release/retention of radionuclides (ReCosy programme) in nuclear waste disposal and to provide tools to apply the results to safety assessment. The project has been organized into 6 task forces: 1) implications of Redox for safety, 2) development of Redox determination methods, 3) Redox response of defined and near-natural systems, 4) Redox reactions of radionuclides, 5) Redox processes in radionuclide transport, and 6) Redox reactions affecting the spent fuel source-term

  11. Effective equivalent dose in the critical group due to release of radioactive effluents

    International Nuclear Information System (INIS)

    Santos, John W.A. dos; Varandas, Luciana R.; Souza, Denise N.; Souza, Cristiano B.F.; Lima, Sandro Leonardo N.; Mattos, Marcos Fernando M.; Moraes, Jose Adenildo T.

    2005-01-01

    To ensure that the emissions of radioactive material by liquid and gaseous pathways are below applicable limits it is necessary to evaluate the effective equivalent dose in the critical group, which is a magnitude that takes into consideration the modeling used and the terms radioactive activity source. The calculation of this dose considers each radionuclide released by the activity of Nuclear plant, liquid and gaseous by, and the sum of the values obtained is controlled so that this dose does not exceed the goals of the regulatory body, the CNEN and the goals established by the Nuclear power plant. To hit these targets various controls are used such as: controls for effluent monitors instrumentation, environmental monitoring programs, effluent release controls and dose calculation in the environment. According to the findings, it is concluded that during the period of operation of the plants, this dose is below of the required limits

  12. Critical review of controlled release packaging to improve food safety and quality.

    Science.gov (United States)

    Chen, Xi; Chen, Mo; Xu, Chenyi; Yam, Kit L

    2018-03-19

    Controlled release packaging (CRP) is an innovative technology that uses the package to release active compounds in a controlled manner to improve safety and quality for a wide range of food products during storage. This paper provides a critical review of the uniqueness, design considerations, and research gaps of CRP, with a focus on the kinetics and mechanism of active compounds releasing from the package. Literature data and practical examples are presented to illustrate how CRP controls what active compounds to release, when and how to release, how much and how fast to release, in order to improve food safety and quality.

  13. Radionuclides in food

    International Nuclear Information System (INIS)

    Fernandez Gomez, Isis Maria

    2008-01-01

    The sources of the presence of radionuclides in food are presented: natural radiation and artificial radiation. The transfer of radionuclides through food chains, intakes of radionuclides to the body with its partners effective doses and typical consumption of basic foods of a rural adult population are exposed as main topics. Also the radiation doses from natural sources and exposure to man by ingestion of contaminated food with radionuclides of artificial origin are shown. The contribution of the food ingestion to the man exposure depends on: characteristics of radionuclide, natural conditions, farming practices and eating habits of the population. The principal international organizations in charge of setting guide levels for radionuclides in food are mentioned: standards, rules and the monitoring. It establishes that a guide is necessary for the food monitoring; the alone CODEX ALIMENTARIUS is applicable to emergency situations and the generic action levels proposed by the CODEX not satisfy all needs (no guiding international levels for planned or existing situations such as NORM). There are handled mainly socio-economic and political aspects. Among the actions to be taken are: to assure a public comprehensive information over the risk evaluation in food; to reinforce the collaboration among the different international organizations (WHO, IAEA, ICRP, EC) in relation with the food of set; to give follow-up to the control of the drinkable water and NORM's presence in the food. In addition, it is possible to create the necessary mechanisms to reduce the number of irrelevant measures and bureaucratic useless steps (certificates); to promote the exchange between the different institutions involved in the topic of the food, with relation to the acquired experiences and learned lessons. Likewise, it might examine the possibility of a multidisciplinary approximation (radioactive and not radioactive pollutants); to elaborate a technical guide to assure the

  14. Ocean model system for radionuclides - validation and application to the Rokkasho coastal area

    International Nuclear Information System (INIS)

    Kobayashi, Takuya

    2010-01-01

    Coastal areas have complex environmental systems and often a high influence from the atmosphere, rivers and the open sea. A nuclear fuel reprocessing plant in Japan releases liquid radioactive waste from a discharge pipe to such a complex coastal area. Consequently, the development of radionuclide migration forecast system in the ocean plays an important rule for assessing the behavior of radionuclides in the coastal area. The development of ocean model systems will be presented and model application will also be described. (author)

  15. Chemical fractionation of radionuclides and stable elements in aquatic plants of the Yenisei River.

    Science.gov (United States)

    Bolsunovsky, Alexander

    2011-09-01

    The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.

  16. Complete release from regulatory control via the density of radioactive contamination of soil of the Chornobyl exclusion zone

    International Nuclear Information System (INIS)

    Bondarenko, Oleg; Fadeev, Mykhaylo; Kireev, Serhiy; Proskura, Mykola

    2008-01-01

    Full text: In this work a general procedure of establishment the criterion of complete release from regulatory control via the density of radioactive contamination of soil of alone areas of the Chornobyl exclusion zone is represented by the following three stages, namely: 1) Justification of the dose criterion of complete release by applying the fundamental approaches of regulating the prolonged exposure of the public on a basement of ICRP Publication No. 82; 2) Justification of a procedure for establishment of dose constraint through evaluation of the statistical distribution of a controlled radiation value through determination of the high boundary of the confidence interval; 3) Generalization of conversion coefficients (via the density of radioactive contamination of soil) and coverage coefficients for the dose forming factors of the public (inhalation intake of transuranium radionuclides both at natural and technogenic dust resuspension, peroral intake of 137 Cs and 90 Sr via food stuff, external exposure from 137 Cs); on a basis of these coefficients average doses and dose constraint of a critical group of the public are calculated. As it is shown in the work, the generalized criterion of complete release from regulatory control via the density of radioactive contamination of soil of the Chornobyl exclusion zone can be defined by dividing the recommended ICRP dose clearance level for situation of the post-accidental prolonged exposure of a critical group of the public, namely, 0.3 mSv·year -1 to the dose conversion coefficient (i.e. transfer from the superficial soil contamination of radioactivity to the dose constraint for the Chornobyl exclusion zone), namely, 12.9 μSv·year -1 /((kBq·M -2 ). Thus, a level of the density of radioactive contamination of soil, that provides the complete release from regulatory control makes 23.3 kBq·M -2 . For completion of the work on justification of the criterion of complete territory release in the conditions of

  17. Three-dimensional simulation of radionuclides dispersion in the stratified estuaries

    International Nuclear Information System (INIS)

    Koziy, L.; Margvelashvili, N.; Maderich, V.; Zheleznyak, M.

    1999-01-01

    THREE-dimensional model of TOXicants transport (THREETOX) was developed for assessment of potential and real emergency situations in the coastal area of seas and the inland water bodies. It includes the high resolution numerical hydrodynamic submodel, dynamic-thermodynamic ice submodel, submodels of suspended sediment and radionuclide transport. The results of two case studies are described. The first one concerns to two-year simulation of the Chernobyl origin radionuclide transport through Dnieper-Bug estuary into the Black sea. In the second case study the simulations were performed for the assessment of potential emergency situation caused by the radionuclide release from reactors and containers with the liquid radioactive wastes scuttled in the Novaya Zemlya fjords (Tsivolki, Stepovogo and Abrosimov). The presented results demonstrate the capability of THREETOX model to describe the wide spatial and temporal range of transport processes in the coastal area of seas. (author)

  18. Analysis of the processes defining radionuclide migration from deep geological repositories in porous medium

    International Nuclear Information System (INIS)

    Brazauskaite, A.; Poskas, P.

    2004-01-01

    Due to the danger of exposure arising from long-lived radionuclides to humans and environment, spent nuclear fuel (SNF) and high level waste (HLW) are not allowed to be disposed of in near surface repositories. There exists an international consensus that such high level and long-lived radioactive wastes are best disposed of in geological repositories using a system of engineered and natural barriers. At present, the geological repository of SNF and HLW has not been realized yet in any country but there is a lot of experience in the assessment of radionuclide migration from deep repositories, investigations of different processes related to the safety of a disposal system. The aim of this study was to analyze the processes related to the radionuclide migration from deep geological repositories in porous medium such as SNF matrix dissolution, release mechanism of radionuclides from SNF matrix, radionuclide solubility, sorption, diffusive, advective transport of radionuclides from the canister and through the engineered and natural barriers. It has been indicated that SNF matrix dissolution, radionuclide solubility and sorption are sensitive to ambient conditions prevailing in the repository. The approaches that could be used for modeling the radionuclide migration from deep repositories in porous medium are also presented. (author)

  19. Evaluation of data on the transfer of radionuclides in the food chain post-Chernobyl action

    International Nuclear Information System (INIS)

    Desmet, G.; Sinnaeve, J.

    1992-01-01

    During the accident at Chernobyl large amounts of radioactive materials were released into the atmosphere and distributed all over Europe. Depending on the trajectories of the radioactive clouds and the large variation of rainfall during its passage through, large local and regional differences in deposition were observed, leading to an enhanced contamination of soil and plants. Consequently, the radionuclides entered the foodchain by several pathways. The radiological consequences of radionuclides discharged from nuclear installations usually are evaluated using doses assessment models. In these models the passage from one compartment into another, e.g. the transfer from soil into plants, from plants into milk or meat is defined by transfer factors, which are influenced by various parameters. From the long term point of view only the long-lived nuclides like 134/137 Cs are important for long term radiation risk assessment after the Chernobyl accident. In this accident the release of radioactive materials took place over a longer time period and varied in rate and radionuclide composition. Some regions of Europe were contaminated several times. To improve radiation dose prediction the CEC has initiated the Post-Chernobyl radiation protection programme 'Evaluation of Data on the Transfer of Radionuclides in the Foodchain' including five main items to be studied by different laboratories: 1. Impact of chemical speciation on the radionuclide transfer in terrestrial ecosystems after a core disruptive accident, especially in soils and plants. 2. Transfer paths of radionuclides in seminatural and natural ecosystems and their role in contaminating the foodchain. 3. Validation of soil-to-plant parameters. 4. Transfer of radionuclides to animals and animal products. 5. Transfer paths in aquatic systems and their importance for the contamination of the foodchain

  20. Sediment and radionuclide transport in rivers: radionuclide transport modeling for Cattaraugus and Buttermilk Creeks, New York

    International Nuclear Information System (INIS)

    Onishi, Y.; Yabusaki, S.B.; Kincaid, C.T.; Skaggs, R.L.; Walters, W.H.

    1982-12-01

    SERATRA, a transient, two-dimensional (laterally-averaged) computer model of sediment-contaminant transport in rivers, satisfactorily resolved the distribution of sediment and radionuclide concentrations in the Cattaraugus Creek stream system in New York. By modeling the physical processes of advection, diffusion, erosion, deposition, and bed armoring, SERATRA routed three sediment size fractions, including cohesive soils, to simulate three dynamic flow events. In conjunction with the sediment transport, SERATRA computed radionuclide levels in dissolved, suspended sediment, and bed sediment forms for four radionuclides ( 137 Cs, 90 Sr, 239 240 Pu, and 3 H). By accounting for time-dependent sediment-radionuclide interaction in the water column and bed, SERATA is a physically explicit model of radionuclide fate and migration. Sediment and radionuclide concentrations calculated by SERATA in the Cattaraugus Creek stream system are in reasonable agreement with measured values. SERATRA is in the field performance phase of an extensive testing program designed to establish the utility of the model as a site assessment tool. The model handles not only radionuclides but other contaminants such as pesticides, heavy metals and other toxic chemicals. Now that the model has been applied to four field sites, including the latest study of the Cattaraugus Creek stream system, it is recommended that a final model be validated through comparison of predicted results with field data from a carefully controlled tracer test at a field site. It is also recommended that a detailed laboratory flume be tested to study cohesive sediment transport, deposition, and erosion characteristics. The lack of current understanding of these characteristics is one of the weakest areas hindering the accurate assessment of the migration of radionuclides sorbed by fine sediments of silt and clay