WorldWideScience

Sample records for level blanket peat

  1. Impact of prescribed and repeated vegetation burning on blanket peat hydrology

    Science.gov (United States)

    Holden, Joseph; Brown, Lee; Palmer, Sheila; Johnston, Kerrylyn; Wearing, Catherine; Irvine, Brian

    2013-04-01

    In some peatlands there has been a tradition over the past century of burning vegetation to manage the landscape for a range of purposes. These include producing an environment suitable for game birds used in the gun sports industry and reducing the biomass fuel load to reduce possible wildfire damage to the peat. However, there have been few studies that have interrogated the impacts of this activity on peatland hydrological processes both at the plot scale and at the catchment scale. The EMBER project measured water tables, overland flow, hydraulic conductivity, stream discharge, and a myriad of aquatic invertebrate and peat physical and water chemistry indicators (at plot and stream scale) in ten upland blanket peat catchments in the UK. Five catchments were subject to a history of prescribed rotational patch burning with burning taking place each year over a proportion of the catchment (typically 5-10 %) but where for an individual patch the interval was typically 10-20 years. The other five catchments acted as controls which were not subject to burning, nor confounded by other detrimental activities such as drainage or forestry. Stream flows were flashier in response to rainfall in the catchments with prescribed burning patches and had greater rainfall to runoff efficiencies. Water tables were found to be significantly shallower with a smaller interquartile range for unburnt catchments. In the burnt catchments, more recently burnt plots had significantly greater mean water table depths and water table residence times were much less frequent within the upper 10 cm of the peat profile compared to plots that been burned more than a decade before. The water table residence curves will be explored in the presentation. The occurrence of overland flow was significantly impacted by both burning and time since burn with significantly less overland flow recorded for more recently burnt sites. This ties in well with our water table data since blanket peat systems are

  2. Global peat resources

    Energy Technology Data Exchange (ETDEWEB)

    Lappalainen, E. [ed.] [Geological Survey of Finland (Finland)

    1996-12-31

    The book provides a detailed review of the world`s peat and peatland resources and their role in the biosphere. It was compiled by 68 peat experts. Reports present the valuable mire ecosystem, its characteristics, and the use of peatlands. Maps and photographs illustrate the distribution of mines and their special characteristics, including raised bogs, aapa mires, blanket bogs, mangrove swamps, swamp forests etc. The book contains a total of 57 chapters, the bulk of then giving surveys of peat resources and use in individual countries. They are grouped under the headings: peatlands in biosphere; general review; Europe; Asia; Africa; North America; Central and South America; Australia (and New Zealand); and use of peatlands. One chapter has been abstracted separately for the IEA Coal Research CD-ROM. 7 apps.

  3. Interaction of Peat Soil and Sulphidic Material Substratum: Role of Peat Layer and Groundwater Level Fluctuations on Phosphorus Concentration

    Directory of Open Access Journals (Sweden)

    Benito Heru Purwanto

    2014-09-01

    Full Text Available Phosphorus (P often becomes limiting factor for plants growth. Phosphorus geochemistry in peatland soil is associated with the presence of peat layer and groundwater level fluctuations. The research was conducted to study the role of peat layer and groundwater level fluctuations on P concentration in peatland. The research was conducted on deep, moderate and shallow peat with sulphidic material as substratum, peaty acid sulphate soil, and potential acid sulphate soil. While P concentration was observed in wet season, in transition from wet to dry season, and in dry season. Soil samples were collected by using peat borer according to interlayer and soil horizon. The results showed that peat layer might act as the main source of P in peatland with sulphidic material substratum. The upper peat layer on sulphidic material caused by groundwater level fluctuations had no directly effect on P concentration in the peat layers. Increased of P concentration in the lowest sulphidic layer might relate to redox reaction of iron in the sulphidic layer and precipitation process. Phosphorus concentration in peatland with sulphidic material as substratum was not influenced by peat thickness. However, depletion or disappearance of peat layer decreased P concentration in soil solution. Disappearance of peat layer means loss of a natural source of P for peatland with sulphidic material as substratum, therefore peat layer must be kept in order to maintain of peatlands.

  4. Why are there few gas bubbles in deep peat in British raised and blanket peat bogs?

    Directory of Open Access Journals (Sweden)

    R.S. Clymo

    2015-08-01

    Full Text Available (1 There is evidence of gas-filled voids - ‘bubbles’ - in deep (> 50–100 cm peat in North America. (2 I used corers, designed to collect samples of accurately known volume, to sample peat profiles down to maximum depth 700 cm at five varied bog sites in northern England and southern Scotland, and measured the proportion of space apparently occupied by bubbles. (3 Of 126 samples in peat below 50 cm depth, three had bubbles occupying 12–15 % of the volume (and one of these was at only 55 cm depth. The other 123 had apparent bubbles distributed in Gaussian fashion, positively and negatively, about zero proportion of total volume and with standard deviation less than 2 %, consistent with these ‘bubbles’ being measurement error. (4 In northern England and southern Scotland, compared with North America, less variable temperature and cooler summers may lead to concentrations of dissolved gas that are generally too low to allow bubbles to form. Even where bubbles do form in summer, they may re-dissolve at winter temperatures.

  5. Caesium dynamics in the peats and associated vegetation of northern Greece and northern Scotland

    International Nuclear Information System (INIS)

    Heaton, B.; Mitchell, R.D.J.; Killham, K.; Veresoglou, D.S.

    1990-01-01

    Sequential analyses have shown that Chernobyl-derived caesium has been largely retained in Greek basin peats (highly cultivated, base-rich, sedge peats) and retained/cycled in Scottish upland peats (uncultivated, base-poor, blanket peats). To investigate the mechanisms of retention and cycling in the Scottish peat/vegetation system, a laboratory experiment was carried out involving 'microcosms' intact peat cores. Festuca ovina was grown from seed in the cores prior to nebuliser-application of simulated rain containing caesium-134. The major factors investigated were competitive ion exchange from ammonium (designed to simulate animal waste inputs), freeze-thaw activity, and cropping (designed to simulate upland grazing). The effects of these factors are discussed in relation to the physio-cochemical and biological properties of the peat and vegetation and to our observations of the movement of caesium in the field. (author)

  6. New Approach in Modelling Indonesian Peat Fire Emission

    Science.gov (United States)

    Putra, E. I.; Cochrane, M. A.; Saharjo, B.; Yokelson, R. J.; Stockwell, C.; Vetrita, Y.; Zhang, X.; Hagen, S. C.; Nurhayati, A. D.; Graham, L.

    2017-12-01

    Peat fires are a serious problem for Indonesia, producing devastating environmental effects and making the country the 3rd largest emitter of CO2. Extensive fires ravaged vast areas of peatlands in Sumatra, Kalimantan and Papua during the pronounced El-Nino of 2015, causing international concern when the resultant haze blanketed Indonesia and neighboring countries, severely impacting the health of millions of people. Our recent unprecedented in-situ studies of aerosol and gas emissions from 35 peat fires of varying depths near Palangka Raya, Central Kalimantan have documented the range and variability of emissions from these major fires. We strongly suggest revisions to previously recommended IPPC's emission factors (EFs) from peat fires, notably: CO2 (-8%), CH4 (-55%), NH3 (-86%), and CO (+39%). Our findings clearly showed that Indonesian carbon equivalent measurements (100 years) might have been 19% less than what current IPCC emission factors indicate. The results also demonstrate the toxic air quality in the area with HCN, which is almost only emitted by biomass burning, accounting for 0.28% and the carcinogenic compound formaldehyde 0.04% of emissions. However, considerable variation in emissions may exist between peat fires of different Indonesian peat formations, illustrating the need for additional regional field emissions measurements for parameterizing peatland emissions models for all of Indonesia's major peatland areas. Through the continuous mutual research collaboration between the Indonesian and USA scientists, we will implement our standardized field-based analyses of fuels, hydrology, peat burning characteristics and fire emissions to characterize the three major Indonesian peatland formations across four study provinces (Central Kalimantan, Riau, Jambi and West Papua). We will provide spatial and temporal drivers of the modeled emissions and validate them at a national level using biomass burning emissions estimations derived from Visible

  7. Characterization of Soil Organic Matter in Peat Soil with Different Humification Levels using FTIR

    Science.gov (United States)

    Teong, I. T.; Felix, N. L. L.; Mohd, S.; Sulaeman, A.

    2016-07-01

    Peat soil is defined as an accumulation of the debris and vegetative under the water logging condition. Soil organic matter of peat soil was affected by the environmental, weather, types of vegetative. Peat soil was normally classified based on its level of humification. Humification can be defined as the transformation of numerous group of substances (proteins, carbohydrates, lipids, etc.) and individual molecules present in living organic matter into group of substances with similar properties (humic substances). During the peat transformation process, content of soil organic matter also will change. Hence, that is important to determine out the types of the organic compound. FTIR (Fourier Transform Infrared) is a machine which is used to differential soil organic matter by using infrared. Infrared is a types of low energy which can determine the organic minerals. Hence, FTIR can be suitable as an indicator on its level of humification. The main objective of this study is to identify an optimized method to characterization of the soil organic content in different level of humification. The case study areas which had been chosen for this study are Parit Sulong, Batu Pahat and UCTS, Sibu. Peat soil samples were taken by every 0.5 m depth until it reached the clay layer. However, the soil organic matter in different humification levels is not significant. FTIR is an indicator which is used to determine the types of soil, but it is unable to differentiate the soil organic matter in peat soil FTIR can determine different types of the soil based on different wave length. Generally, soil organic matter was found that it is not significant to the level of humification.

  8. Causes of degradation and erosion of a blanket mire in the southern Pennines, UK

    NARCIS (Netherlands)

    Yeloff, D.; Hunt, C.O.; Labadz, J.C.

    2006-01-01

    This study investigates the causes of erosion and degradation of March Haigh, a blanket mire in the southern Pennines (UK), over a period of 160 years starting in 1840 AD. Peat samples taken from the site were dated using 210Pb; their humification and magnetic susceptibility were measured; and they

  9. Determining critical groundwater level to prevent degraded peatland from severe peat fire

    Science.gov (United States)

    Putra, E. I.; Cochrane, M. A.; Vetrita, Y.; Graham, L.; Saharjo, B. H.

    2018-05-01

    Peat fires have been a severe recurrent problem for Indonesia, but droughts due to prolonged dry season aggravate burning conditions. To get a better understanding of this issue, we studied fire conditions in a portion of the ex-Mega Rice Project (MRP) area, Central Kalimantan. To examine fire season and hydrology factors affecting peat fires we analyzed daily TRMM data, Nino 3.4 SST Anomalies, and changing groundwater levels (GWL) from 300 dipwells. Our results quantify time-lags between the period of lowest precipitation and the lowest GWL; providing some ability to predict fire risk in advance of the lowest GWL. The rise of Nino 3.4 SST anomalies is significant risk factors for peat fire as they signify dry months which may yield large fire occurrences. GWL in 2011 was lower than in 2012, but fires were more frequent in 2012, indicating that low precipitation amounts in the wet season of 2011/2012 left the peat in a dry condition early in 2012. Most of the fires occurred in areas with GWL less than -30 cm, powerfully illustrating the importance of maintaining GWL at more than -10 cm, to prevent degraded peatlands from experiencing surface and deep peat fires.

  10. Land management as a factor controlling dissolved organic carbon release from upland peat soils 2: changes in DOC productivity over four decades.

    Science.gov (United States)

    Clutterbuck, B; Yallop, A R

    2010-11-15

    Increasing DOC concentrations in surface waters have been observed across parts of Europe and North America over the past few decades. Most proposed explanations for these widespread trends invoke climate change or reductions in sulphate deposition. However, these factors do not seem apposite to explain either the fine-scale (within kilometres) or regional-scale spatial variation in DOC concentrations observed across the UK. We have reconstructed DOC concentrations and land use for one North Pennine and five South Pennine catchments (UK), located in three discrete areas, over the last four decades. Rainfall, temperature and sulphate deposition data, where available, were also collated and the potential influence of these factors on surface water DOC concentrations was assessed. Four of the six catchments examined showed highly significant (pDOC (hDOC) concentrations in drainage waters over the period 1990-2005. Changes in temperature and sulphate deposition may explain 20-30% of this trend in these four catchments. However, the rapid expansion of new moorland burn on blanket peat can explain a far greater degree (>80%) of the change in hDOC. Far smaller increases in hDOC (10-18%) were identified for the two remaining catchments. These two sites experienced similar changes in sulphur deposition and temperature to those that had seen largest increases in DOC, but contained little or no moorland burn management on blanket peat. This study shows that regional-scale factors undoubtedly underlie some of the recent observed increases in drainage humic coloured DOC. However, changes in land management, in this case the extensive use of fire management on blanket peat, are a far more important driver of increased hDOC release from upland catchments in some parts of the UK. It suggests that the recent rapid increase in the use of burning on blanket peat moorland has implications for ecosystem services and carbon budgets. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Sphagnum restoration on degraded blanket and raised bogs in the UK using micropropagated source material: a review of progress

    Directory of Open Access Journals (Sweden)

    S.J.M Caporn

    2018-05-01

    Full Text Available There is a growing demand for a supply of Sphagnum to re-introduce to degraded peatlands. However, available supplies of Sphagnum of the desired species are often limited. We describe the propagation of Sphagnum from vegetative material in sterile tissue culture and the introduction of juvenile mosses into the field. Sphagnum produced in the laboratory in three different forms (beads, gel and plugs was introduced to different peatland surfaces on upland degraded blanket bog and lowland cut-over peatland in northern England. On degraded blanket bog, the establishment of mixed-species Sphagnum plugs was typically 99 % while the survival of beads was much lower, ranging from little above zero on bare eroding peat to a maximum of 12 % on stabilised peat surfaces. On lowland cut-over peatland, all trials took place on peat with an expanding cover of Eriophorum angustifolium and tested Sphagnum gel as well as beads and plugs. This work showed that survival and establishment of plugs was high (99 % and greater than for beads. Sphagnum gel reached a cover of 95 % in two years. The vegetative micropropagation of Sphagnum offers an effective source of Sphagnum for re-introduction to degraded peatlands.

  12. Water and peat chemistry comparisons of natural and peat-harvested peatlands across Canada and their relevance to peatland restoration

    International Nuclear Information System (INIS)

    Windmulder, H.L.; Rochefort, L.; Vitt, D.H.

    1996-01-01

    Water and peat chemistry comparisons of four post-harvested and neighbouring, undisturbed peatlands across Canada show that harvesting alters chemical conditions. Commercial harvesting removes the surface peat and exposes layers farther down the peat deposit. The newly exposed peat layers that were formed in earlier developmental stages of the peatland can be more minerotrophic and/or more variable in chemical composition than undisturbed bog peat. All the harvested sites were originally bogs. Only one site, which had minimal peat removed, presently has chemical conditions somewhat similar to the original surface, with low elemental levels typical of bogs. Two sites are now chemically similar to poor fens and one site is similar to a moderate-rich fen. Levels of sodium, potassium, calcium, magnesium, sulphate and chloride in three of the harvested sites are higher than normal values found in natural, unharvested bogs, and result from the exposure of fen peat. Higher levels of ammonium-nitrogen and nitrate-nitrogen in the peat and water of all the harvested sites are present, with higher ammonium associated with wetter sites and higher nitrate levels associated with drier sites

  13. Radionuclides in peat bogs and energy peat

    International Nuclear Information System (INIS)

    Helariutta, K.; Rantavaara, A.; Lehtovaara, J.

    2000-06-01

    The study was aimed at improving the general view on radionuclides contents in energy peat produced in Finland. The annual harvest of fuel peat in 1994 was studied extensively. Also thirteen peat bogs used for peat production and one bog in natural condition were analysed for vertical distributions of several radionuclides. These distributions demonstrate the future change in radioactivity of energy peat. Both natural nuclides emitting gamma radiation ( 238 U, 235 U, 232 Th, 226 Ra, 40 K) and radiocaesium ( 137 Cs, 134 Cs) origin in fallout from a nuclear power plant accident (1986) and in atmospheric nuclear weapon tests were analysed. The beta and alpha active natural nuclides of lead and polonium ( 210 Pb, 210 Po) were determined on a set of peat samples. These nuclides potentially contribute to radiation exposure through inhalation when partially released to atmosphere during combustion of peat. The activity concentrations of natural radionuclides often increased towards the deepest peat bog layers whereas the radioactive caesium deposited from atmosphere was missing in the deep layers. In undisturbed surface layers of a natural bog and peat production bogs the contents of 210 Pb and 210 Po exceeded those of the deeper peat layers. The nuclides of the uranium series in the samples were generally not in radioactive equilibrium, as different environmental processes change their activity ratios in peat. Radiation exposure from handling and utilisation of peat ash was estimated with activity indices derived from the data for energy peat harvested in 1994. Intervention doses were exceeded in a minor selection of samples due to 137 Cs, whereas natural radionuclides contributed very little to the doses. (orig.)

  14. Peat - The sustainable energy resource in Finland

    International Nuclear Information System (INIS)

    1994-01-01

    In Finland the level of energy consumption for heating, transportation and industry is higher than in many other European countries. This is due to the northern position of the country and also to the fact that Finland is sparsely inhabited. Peat is one of the Finnish domestic energy resources. This brochure provides a compact package of background information on fuel peat. All the data presented concerning the production and use of peat, employment, investments in the peat industry, emission levels resulting from the production and use of peat, new combustion technologies and peatland resources, have been collected from documents and other sources that are accessible to the general public

  15. Diminishing peat oxidation of agricultural peat soils by infiltration via submerged drains

    NARCIS (Netherlands)

    Akker, van den J.J.H.; Hendriks, R.F.A.

    2017-01-01

    Oxidation of peat soils used in dairy farming in the western peat area of The Netherlands causes subsidence rates up to 13 mm.y and emissions of CO2 to about 27 t.ha.y. In 2003 experiments started with subsurface irrigation by submerged drains to raise groundwater levels to reduce oxidation and so

  16. Peat

    Science.gov (United States)

    Apodaca, Lori E.

    2013-01-01

    The article looks at the U.S. peat market as of July 2013. Peat is produced from deposits of plant organic materials in wetlands and includes varieties such as reed-sedge, sphagnum moss, and humus. Use for peat include horticultural soil additives, filtration, and adsorbents. Other topics include effects of environmental protection regulations on peat extraction, competition from products such as coir, composted organic waste, and wood products, and peatland carbon sinks.

  17. Novel blanket design for ICTR's

    International Nuclear Information System (INIS)

    Abdel-Khalik, S.I.; Conn, R.W.; Wolfer, W.G.; Larsen, E.N.; Sviatoslavsky, I.N.

    1978-01-01

    A novel blanket design for ICTRs is described. This blanket is used in SOLASE, the conceptual laser fusion reactor of the University of Wisconsin. The blanket to be described offers numerous advantages, including low cost, low weight, low induced radioactivity levels, the potential for hands-on maintenance, modular construction, low pressure, ability to decouple first wall and blanket coolant temperatures, adequate breeding, low tritium inventory and leakage, and sufficiently long life

  18. Evaluation of the activity levels in fusion reactor blankets

    International Nuclear Information System (INIS)

    Gruber, J.

    1977-05-01

    The activation of a fusion reactor blanket (316 SS or V-10Cr-10Ti as structure) with a minimum lithium inventory has been calculated for 0.83 MW/m 2 wall load. The resulting radiation levels and waste problems are discussed. The dose rate near the steel structure will always be higher than 0.1 rem/h due to its niobium content. After 200 to 100,000 years of decay the potential biological hazard originating from this high level fusion reactor waste (with plutonium recyclation). (orig.) [de

  19. The requirements for processing tritium recovered from liquid lithium blankets: The blanket interface

    International Nuclear Information System (INIS)

    Clemmer, R.G.; Finn, P.A.; Greenwood, L.R.; Grimm, T.L.; Sze, D.K.; Bartlit, J.R.; Anderson, J.L.; Yoshida, H.; Naruse.

    1988-03-01

    We have initiated a study to define a blanket processing mockup for Tritium Systems Test Assembly. Initial evaluation of the requirements of the blanket processing system have been started. The first step of the work is to define the condition of the gaseous tritium stream from the blanket tritium recovery system. This report summarizes this part of the work for one particular blanket concept, i.e., a self-cooled lithium blanket. The total gas throughput, the hydrogen to tritium ratio, the corrosive chemicals, and the radionuclides are defined. The key discoveries are: the throughput of the blanket gas stream (including the helium carrier gas) is about two orders of magnitude higher than the plasma exhaust stream;the protium to tritium ratio is about 1, the deuterium to tritium ratio is about 0.003;the corrosion chemicals are dominated by halides;the radionuclides are dominated by C-14, P-32, and S-35;their is high level of nitrogen contamination in the blanket stream. 77 refs., 6 figs., 13 tabs

  20. Measurement of natural activity in peat ashes

    International Nuclear Information System (INIS)

    Suomela, J.

    1985-01-01

    High proportions of radioactive materials in peat ashes may involve radiation hazards during handling and deposition of these waste materials. Measurements have been performed to determine the content of radioactive materials in ashes from peat burning. The activities in fly ash and ''solid'' ash in seven peat-fired power plants in Sweden are presented. The methods of analysing and measuring peat ashes for activity from different radionuclides are described. The activity levels in ash samples are given

  1. Peat Research Seminar

    International Nuclear Information System (INIS)

    1993-01-01

    The VTT Seminar on Peat Research was held in Espoo, Finland, on April 14-15, 1993. The programme consisted of technical session on Peat in Energy Production, Peat Research Programs, Peat Production and Harvesting Technology

  2. Peat 2003. Production, use, environmental impact

    International Nuclear Information System (INIS)

    2004-01-01

    This report discusses the use of peat for energy production and other purposes, laws and other regulations affecting peat production and use, environmental impact, market situation and international statistics regarding peat production. In Sweden, the extraction and use of peat for energy production is regulated by several laws. Harvesting concessions must be approved by the county council. All combustion plants must be reported, or verified by regional or central authorities, depending on the size of the plant. Most important in this process is to verify the maximum emission levels permitted for sulphur, nitrogen oxides, particles, etc. Since 1991, a law on municipal energy planning requires descriptions of environmental consequences. Thus, environmental considerations must govern energy planning. Energy taxation in Sweden was changed in 1993. At present, the sulphur tax on fuel peat amounts to SEK 30 per kg of sulphur. Nitrogen oxides are also subject to a tax of SEK 40 per emitted kg. For peat, energy and environmental taxes total SEK 0.02 per kWh, excluding VAT. Peat harvesting for the production of energy aroused interest in the early 1980s as a consequence of the increased energy prices. In 2003, about 2,628,000 cubic metres of fuel peat were harvested in Sweden. The fuel peat is used mainly for production of hot water in district heating plants. In 2003, the total use of fuel peat amounted to 4,0 TWh. In addition to fuel peat, about 1,825,000 cubic metres of peat litter (mainly for horticultural use) was produced. In 2003, imports amounted to 382,3000 metric tons or 1.3 million cubic metres of peat. Exports amounted to 103,000 metric tons, consisting primarily of peat for horticultural use. The peat market in Sweden is divided into the energy market and the cultivation market. Political decisions regarding combustion taxes have a great impact on the competitive advantages of different fuels. The major competitors to peat are coal, oil, and renewable energy

  3. Effects of environmental and anthropogenic determinants on changes in groundwater levels in selected peat bogs of Slowinski National Park, northern Poland

    Science.gov (United States)

    Chlost, Izabela; Cieśliński, Roman

    2018-03-01

    The present study focuses on two Baltic-type peat bogs in Slowinski National Park, namely that at Żarnowskie and at Kluki, located in the Lake Łebsko catchment and both characterised by a centrally located dome with a very marshy fringe area featuring an emerging marshy coniferous forest (Vaccinio uliginosi-Pinetum). The Żarnowskie bog is under active protection. A total of 24 flow barriers were installed in drainage ditches during the years 2006 and 2007. The purpose of these barriers was to put a halt to water outflow. In addition, 30 hectares of young pine forest were cleared in order to decrease loss of water via evapotranspiration. Kluki peat bog is only partially protected by Polish law. The lack of efforts to prevent outflow via the canal is due to the fact that the canal is utilised to drain meadows in the vicinity of the village of Łokciowe outside of the national park. Peat formation no longer occurs in this peat bog. The hydrological condition of the bog is catastrophic as a result of its main canal, referred to as Canal C9, which is 2.5 to 3.0 m deep and 10 m wide in places. Both peat bogs are monitored for fluctuations in groundwater. Research has shown that changes in water levels fluctuate based on season of the year and geographical location, which is illustrated quite well using the two studied peat bogs. The water retention rate of the Żarnowskie peat bog may be considered fairly high and is likely to improve due to protective measures enabled by Polish environmental laws. The water retention rate of the bog is consistently improving thanks to these measures, fluctuations in water level are small and the water level does not drop under 0.5 m below ground level even under extreme hydrometeorological conditions. This yields optimum conditions for renewed peat formation in this area. One potential threat is the Krakulice peat extraction facility, which is located in the southern part of the bog close to the boundary with the national park.

  4. Will blocking historical drainage ditches increase carbon sequestration in upland blanket mires of Southwest England?

    Science.gov (United States)

    Le Feuvre, N.; Hartley, I.; Anderson, K.; Luscombe, D.; Grand-Clement, E.; Smith, D.; Brazier, R.

    2012-04-01

    Peat soils in the United Kingdom are estimated to store a minimum of 3,121Mt C (Lindsay, 2010). Despite being such a large carbon store the annual imbalance between uptake and release is small and susceptible to change in response to land management, atmospheric deposition and climate change. The upland blanket mires of Southwest England have been subject to extensive drainage and are particularly vulnerable to climate change as they lie at the lower edge of the peatland climatic envelope. The Mires-on-the-Moors project, funded by South West Water will restore over 2000 hectares of drained mire by April 2015. Herein, we question whether this restoration, which will block historical drainage ditches will allow the blanket bogs of Exmoor and Dartmoor National Parks to recover their ecohydrological functionality. We hypothesise that such mire restoration will increase the resilience of these ecosystems to climate change and will return these upland mires to peat forming/carbon sequestering systems. A method is proposed which aims to understand the processes driving gaseous carbon exchange and peat formation in an upland blanket bog and quantifies the effect restoration has on these processes. We propose to measure the spatial variation in gas fluxes with respect to structural features of the mire; drainage ditches and nanotopes. The role of vegetation; the community composition, phenology and health will be explored as well as environmental variables such as water table depths, temperature and photosynthetically active radiation. Importantly, the experiment will partition below ground respiration to assess the environmental controls and effect of restoration on autotrophic and heterotrophic respiration separately. Unusually, it will be possible to collect both pre- and post-restoration data for two experimental sites with existing intensive hydrological monitoring (baseline monitoring of water table depths at 15 minute timesteps has been in place for > 1 year at ca

  5. Levels of potentially toxic metals in water, sediment and peat from Wonderfonteinspruit, North West Province, South Africa.

    Science.gov (United States)

    Nsaka, Ntumba C; McCrindle, Robert I; Ambushe, Abayneh A

    2018-04-30

    Environmental monitoring of the levels of potentially toxic metals is of importance because of possible adverse effects on living species. This study was conducted to assess the levels of Cd, Cr, Cu, Hg, Mn, Pb, U and V in water, sediment and peat samples collected from the region of Wonderfonteinspruit. Water samples were simply filtered and acidified with HNO 3 prior to analysis. Sediment and peat were oven-dried, ground, sieved and mineralised using a microwave digestion system. Concentrations of the selected elements in all samples were determined by inductively coupled plasma-mass spectrometry. A Zeeman mercury analyser was also used for quantification of Hg in the same sediment and peat samples. The method validation was carried out using SRM 1643e water and BCR 320R sediment certified reference materials. The results showed no significant difference at 95% level of confidence between the certified and measured values after using the Student's t-test. The levels of Cd, Cr, Cu, Pb, V and U found in rivers and dams were lower than the tentative South African water quality range guideline for domestic and irrigation purposes. However, water from dams and certain rivers was unsuitable for irrigation and domestic use.

  6. Radionuclides in peat bogs and energy peat; Turvesoiden ja polttoturpeen radionuklidit

    Energy Technology Data Exchange (ETDEWEB)

    Helariutta, K.; Rantavaara, A. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Lehtovaara, J. [Vapo Oy, Jyvaeskylae (Finland)

    2000-06-01

    The study was aimed at improving the general view on radionuclides contents in energy peat produced in Finland. The annual harvest of fuel peat in 1994 was studied extensively. Also thirteen peat bogs used for peat production and one bog in natural condition were analysed for vertical distributions of several radionuclides. These distributions demonstrate the future change in radioactivity of energy peat. Both natural nuclides emitting gamma radiation ({sup 238}U, {sup 235}U, {sup 232}Th, {sup 226}Ra, {sup 40}K) and radiocaesium ({sup 137}Cs, {sup 134}Cs) origin in fallout from a nuclear power plant accident (1986) and in atmospheric nuclear weapon tests were analysed. The beta and alpha active natural nuclides of lead and polonium ({sup 210}Pb, {sup 210}Po) were determined on a set of peat samples. These nuclides potentially contribute to radiation exposure through inhalation when partially released to atmosphere during combustion of peat. The activity concentrations of natural radionuclides often increased towards the deepest peat bog layers whereas the radioactive caesium deposited from atmosphere was missing in the deep layers. In undisturbed surface layers of a natural bog and peat production bogs the contents of {sup 210}Pb and {sup 210}Po exceeded those of the deeper peat layers. The nuclides of the uranium series in the samples were generally not in radioactive equilibrium, as different environmental processes change their activity ratios in peat. Radiation exposure from handling and utilisation of peat ash was estimated with activity indices derived from the data for energy peat harvested in 1994. Intervention doses were exceeded in a minor selection of samples due to {sup 137}Cs, whereas natural radionuclides contributed very little to the doses. (orig.)

  7. Peat 2000. Resources, use, environmental impact

    International Nuclear Information System (INIS)

    2001-01-01

    This report discusses peat as a natural resource. It describes the peat land area, the peat harvest area, the use of peat for energy production and other purposes, laws and other regulations affecting peat production and use, environmental impact, market situation, trade, research and development, and the government grant to the peat industry. In Sweden, the extraction and use of peat for energy production is regulated by several laws. A company planning peat extraction must first apply for an examination concession. Then a harvesting concession must be approved by the county council. All combustion plants must be reported, or verified by regional or central authorities, depending on the size of the plant. Most important in this process is to verify the maximum emission levels permitted for sulphur, nitrogen oxides, particles, etc. Since 1991, a law on municipal energy planning requires descriptions of environmental consequences. Thus, environmental considerations must govern energy planning. Energy taxation in Sweden was changed in 1993. At present, the sulphur tax on fuel peat amounts to SEK 30 per kg of sulphur. Nitrogen oxides are also subject to a tax of SEK 40 per emitted kg. For peat, energy and environmental taxes total SEK 0.02 per kWh, excluding VAT. More than six millions hectares have been defined as peat land (with a peat layer of more than 30 cm) in Sweden, which means that about 15 per cent of the total land area consists of peat lands. Thinner peat layers (wet mineral soils) cover an additional 10 per cent of the land area. At the end of 1999 concessions for fuel peat harvesting had been granted for 45,000 hectares or 0.8 per cent of the total peat land area. Peat harvesting for the production of energy aroused interest in the early 1980s as a consequence of the energy crises. In 2000, about 1,372,000 cubic metres of fuel peat were harvested in Sweden. The fuel peat is used mainly for production of hot water in heating plants. In 2000, the total use

  8. Peat in environmental management

    International Nuclear Information System (INIS)

    Rinttilae, R.

    1998-01-01

    Peat is the largest natural resource of Finland. The DS-reserves of peat are more than seven times larger than those of wood. Peat is known as a domestic source of energy. Peat is, however, more than an energy source. The most significant problem of water protection in Finland is the eutrophication of the water courses. The reduction of concentrated loads and large emissions sources has up to now been the target for the water protection. The control of diffuse loads has been more difficult. The environmental use of peat can reduce the loads on watercourses, and especially the diffuse emissions. The natural and unique properties of peat can be utilized in several targets: agriculture, pisciculture, fur farming, in small and medium sized industry, and in processing of waste waters of both municipalities and rural areas, as well as in different environmental hazards. The present use of environmental peat is just a small fragment of the annual growth of peat reserves in Finland. The amount of protected mires is about ten times larger than the amount of peatlands taken into peat production. The use of environmental peat makes it possible to reduce the diffuse loads significantly in the future. This, however, requires willingness of cooperation and development by the entrepreneurs, authorities, and peat producers. The present use of agricultural peat binds about three times more phosphor and nearly one and a half fold nitrogen fertilizers compare to the emissions caused by peat production. It has to be noticed that the utilization of peat in reduction of environmental loads does not cause any secondary waste problem. The final product formed can usually be composted and used e.g. in soil remediation or in construction of green areas. The tightening environmental regulations and international agreements increase the utilization of peat. As the demand of peat increased the quality requirements for peat will be increased. Certain grain size and the restoration of the

  9. Peat 2002. Resources, use, environmental impact

    International Nuclear Information System (INIS)

    2003-01-01

    This report discusses the use of peat for energy production and other purposes, laws and other regulations affecting peat production and use, environmental impact, market situation and international statistics regarding peat production. In Sweden, the extraction and use of peat for energy production is regulated by several laws. A company planning peat extraction must first apply for an examination concession. Then a harvesting concession must be approved by the county council. All combustion plants must be reported, or verified by regional or central authorities, depending on the size of the plant. Most important in this process is to verify the maximum emission levels permitted for sulphur, nitrogen oxides, particles, etc. At present, the sulphur tax on fuel peat amounts to SEK 30 per kg of sulphur (1 USD approx. 7.8 SEK). Nitrogen oxides are also subject to a tax of SEK 40 per emitted kg. For peat, energy and environmental taxes total SEK 0.02 per kWh, excluding VAT. Peat harvesting for the production of energy aroused interest in the early 1980s as a consequence of the energy crises. In 2002, about 2,885,000 cubic metres of fuel peat were harvested in Sweden. The fuel peat is used mainly for production of hot water in heating plants. In 2001, the total use of fuel peat amounted to 4.1 TWh. In addition to fuel peat, about 1,800,000 cubic metres of peat litter (mainly for horticultural use) was produced. In 2001, imports amounted to 329,311 metric tons or 1.1 million cubic metres of peat. Exports amounted to 91,000 metric tons, consisting primarily of peat for horticultural use. Fuel peat is used at district heating power plants. Political decisions regarding combustion taxes have a great impact on the competitive advantages of different fuels. The major competitors to peat are coal, oil, and renewable energy sources. Some companies are privately owned, while others are owned by municipalities, which also manage district heating plants and thereby integrate

  10. Peat in the mountains of New Guinea

    Directory of Open Access Journals (Sweden)

    G.S. Hope

    2015-11-01

    Full Text Available Peatlands are common in montane areas above 1,000 m in New Guinea and become extensive above 3,000 m in the subalpine zone. In the montane mires, swamp forests and grass or sedge fens predominate on swampy valley bottoms. These mires may be 4–8 m in depth and up to 30,000 years in age. In Papua New Guinea (PNG there is about 2,250 km2 of montane peatland, and Papua Province (the Indonesian western half of the island probably contains much more. Above 3,000 m, peat soils form under blanket bog on slopes as well as on valley floors. Vegetation types include cushion bog, grass bog and sedge fen. Typical peat depths are 0.5‒1 m on slopes, but valley floors and hollows contain up to 10 m of peat. The estimated total extent of mountain peatland is 14,800 km2 with 5,965 km2 in PNG and about 8,800 km2 in Papua Province. The stratigraphy, age structure and vegetation histories of 45 peatland or organic limnic sites above 750 m have been investigated since 1965. These record major vegetation shifts at 28,000, 17,000‒14,000 and 9,000 years ago and a variable history of human disturbance from 14,000 years ago with extensive clearance by the mid-Holocene at some sites. While montane peatlands were important agricultural centres in the Holocene, the introduction of new dryland crops has resulted in the abandonment of some peatlands in the last few centuries. Despite several decades of research, detailed knowledge of the mountain peatlands is poor and this is an obstacle to scientific management.

  11. Development of small-scale peat production; Pienturvetuotannon kehittaeminen

    Energy Technology Data Exchange (ETDEWEB)

    Erkkilae, A.; Kallio, E. [VTT Energy, Jyvaeskylae (Finland)

    1997-12-01

    The aim of the project is to develop production conditions, methods and technology of small-scale peat production to such a level that the productivity is improved and competitivity maintained. The aim in 1996 was to survey the present status of small-scale peat production, and research and development needs and to prepare a development plan for small-scale peat production for a continued project in 1997 and for the longer term. A questionnaire was sent to producers by mail, and its results were completed by phone interviews. Response was obtained from 164 producers, i.e. from about 75 - 85 % of small-scale peat producers. The quantity of energy peat produced by these amounted to 3.3 TWh and that of other peat to 265 000 m{sup 3}. The total production of energy peat (large- scale producers Vapo Oy and Turveruukki Oy included) amounted to 25.0 TWh in 1996 in Finland, of which 91 % (22.8 TWh) was milled peat and 9 % (2.2 TWh) of sod peat. The total production of peat other than energy peat amounted to 1.4 million m{sup 3}. The proportion of small-scale peat production was 13 % of energy peat, 11 % of milled peat and 38 % of sod peat. The proportion of small-scale producers was 18 % of other peat production. The results deviate clearly from those obtained in a study of small-scale production in the 1980s. The amount of small-scale production is clearly larger than generally assessed. Small-scale production focuses more on milled peat than on sod peat. The work will be continued in 1997. Based on development needs appeared in the questionnaire, the aim is to reduce environmental impacts and runoff effluents from small- scale production, to increase the efficiency of peat deliveries and to reduce peat production costs by improving the service value of machines by increasing co-operative use. (orig.)

  12. Peat 1999. Resources, use, environmental impact

    International Nuclear Information System (INIS)

    2000-01-01

    This report discusses peat as a natural resource. It describes the peat land area, the peat harvest area, the use of peat for energy production and other purposes, laws and other regulations affecting peat production and use, environmental impact, market situation, trade, research and development, and the government grant to the peat industry. In Sweden, the extraction and use of peat for energy production is regulated by several laws. A company planning peat extraction must first apply for an examination concession. Then a harvesting concession must be approved by the county council. All combustion plants must be reported, or verified by regional or central authorities, depending on the size of the plant. Most important in this process is to verify the maximum emission levels permitted for sulphur, nitrogen oxides, particles, etc. Since 1991, a law on municipal energy planning requires descriptions of environmental consequences. Thus, environmental considerations must govern energy planning. Energy taxation in Sweden was changed in 1993. At present, the sulphur tax on fuel peat amounts to SEK 30 per kg of sulphur. Nitrogen oxides are also subject to a tax of SEK 40 per emitted kg. For peat, energy and environmental taxes total SEK 0.02 per kWh, excluding VAT. More than six millions hectares have been defined as peat land (with a peat layer of more than 30 cm) in Sweden, which means that about 15 per cent of the total land area consists of peat lands. Thinner peat layers (wet mineral soils) cover an additional 10 per cent of the land area. At the end of 1999 concessions for fuel peat harvesting had been granted for 45 900 hectares or 0.8 per cent of the total peat land area. Peat harvesting for the production of energy aroused interest in the early 1980s as a consequence of the energy crises. In 1999, about 2 650 000 cubic metres of fuel peat were harvested in Sweden. The fuel peat is used mainly for production of hot water in heating plants. In 1999, the total use

  13. International trade with peat and peat products - a challenge to international standardization

    Energy Technology Data Exchange (ETDEWEB)

    Schmilewski, G; Guenther, J [Institut fuer Torf- und Humusforschung GmbH (ITH), Bad Zwischenahn (Germany, F.R.)

    1990-01-01

    On a worldwide scale raised bog peat is the most important basic material for the production of growing media. Peat has greatly contributed to the realization of modern, standardized and even computer-controlled growing techniques in commercial horticulture. No other material can truly compete with the outstanding physical, chemical and biological properties of peat. All present and future substitutes will have to stand comparison with peat. Nonetheless, many other organic, mineral and synthetic materials are use in horticulture mainly to adjust the physical properties of growing media to new growing methods. As a direct or indirect consequence thereof, the spared raw material peat is a fact which is considered progressive in industrial countries strongly characterized by nature conservational ideas also. Some peat consuming countries do not have any indigenous peat resources and meet their demands with imports. Other countries, such as the Fed. Rep. of Germany, the Scandinavian countries and the USSR export considerable amounts of peat and peat products. International transactions have not only increased for big industries, but also for the peat industry. For the grower and for the producer of growing media alike, the knowledge of growing media properties are of fundamental importance. Various standard methods for the analysis of peat and growing media have been developed by national organizations and are being used just as manifold. In some cases national standards have derived from these.

  14. Peat or no peat: Why do the Rajang and Mahakam Deltas differ?

    Energy Technology Data Exchange (ETDEWEB)

    Gastaldo, Robert A. [Department of Geology, Colby College, 5807 Mayflower Hill Drive, Waterville, ME 04901 (United States)

    2010-08-01

    Coastal and deltaic Holocene peat accumulations around the equatorial island of Borneo, Southeast Asia, have served as models for economic coal-bearing sequences in the stratigraphic record. Although climatic conditions, vegetational communities, and sedimentary regimes are comparable, peat accumulations are not found on both the western and eastern sides of the island. The Rajang River delta and coastal plain, Sarawak, East Malaysia, are covered in areally extensive, thick peat deposits that have attained at least a thickness of > 13 m in ombrogenous peat domes (Marudi, Baram River). Peat-swamp biomass began to accumulate over Pleistocene podzols when sea level stabilized {proportional_to} 7.5 ka and delta progradation was initiated. The Mahakam River delta and coastal plain, East Kalimantan, Indonesia, also began progradation at this time, but there is no evidence in any part of the coastal region for peat accumulation. Rather, poorly developed organic-rich gleysols occur throughout the delta plain. Both the Rajang River and Mahakam River deltas are tidally influenced, fine-grained systems, with a sediment provenance in the Central Massif. Sediment transported through the Rajang River delta differs in that as much as 60% of the clay minerals deposited in the system are mixed layer (I/S) and expandable (K/E) clays that act to restrict pore water flow in the tidal and overbank deposits that comprise the delta plain. These result in the development of an aquiclude above which paludal conditions develop, promoting accumulation of organic matter. In contrast, there is a low proportion of mixed layer and expandable clays transported in the Mahakam River system. This precludes the development of a stilted water table within the delta, allowing for organic matter recycling without peat accumulation. The presence of a high proportion of expandable clay minerals on the western side of Borneo is a reflection of the weathering and eroding source rocks on this side of the

  15. Development of peat-oil (POM) and peat-alcohol (PAM) slurries as alternative fuels

    Energy Technology Data Exchange (ETDEWEB)

    Clemens, D F

    1983-11-01

    The preparation and evaluation of peat/No. 2 fuel oil mixtures (POM) and peat/methanol mixtures (PAM) is described. POM and PAM prepared using North Carolina peat and having varied peat loadings, peat moisture contents and peat particle sizes have been studied by measuring slurry sedimentation ratios and drain times from sedimentation tubes. The peat moisture content was particularly crucial in forming stable slurries. The effect of a variety of additives at 0.5-1.0 wt% on sedimentation ratios, drain times and viscosities was studied. Calorimetric studies of several PAM and POM slurries as well as preliminary combustion tests of POM slurries in a salamander burner are also reported.

  16. Origins of mineral matter in peat marsh and peat bog deposits, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Buendia, A.M. [Unidad Tecnica del Marmol, AIDICO, Cami de Castella, 4, 03660 Novelda, Alicante (Spain); Whateley, M.K.G. [Rio Tinto Technical Services, Castlemead, Lower Castlemead, BS99 7YR Bristol (United Kingdom); Bastida, J.; Urquiola, M.M. [Dpto. Geologia, Univ. Valencia, Dr. Moliner 50. 46100 Burjasot, Valencia (Spain)

    2007-07-02

    The mineralogy of three back-barrier peat marshes (Torreblanca, Benicasim and Moncofar marshes) from Eastern Spain and one peat bog (Orihuela del Tremedal bog) from central east Spain have been investigated, using X-ray diffraction (XRD) and scanning electronic microscope (SEM) techniques. A combination of XRD methods was used to quantify the mineralogy of dried bulk peat samples. The water source in the peat marshes is both continental and marine. Water is highly mineralised. Water flow is both low and slow (accumulative system). The water source in the peat bog is continental, draining from the hill. The higher concentration of ions in the water of the back-barrier peat marshes leads to a higher concentration of authigenic minerals in the peat marshes compared to the peat bog. Three main mineral origins have been recognized, namely: detrital, syngenetic-epigenetic and biogenic. The more important contribution comes from the detrital system. Biogenic and bio-influenced minerals are the main non-detrital minerals in the peatlands. This paper discusses the biogenic origin of halite (and other minor halides and sulphates, such as, sylvite, carnalite, epsomite, glauberite, mirabilite and anhydrite?) from halophytic plants, as well as amorphous silica (opal-A) from sponge spicules and phytoliths of several plants. Pyrite in the peat bog has both syngenetic and epigenetic origins from plant decomposition and sulphur release. In the peat marsh the pyrite has a syngenetic origin from sulphate reduction (S{sub sulphate} {yields} S{sub pyritic}), and an epigenetic origin in the older peat, from plant decomposition (S{sub organic} {yields} S{sub pyritic}). (author)

  17. New record in peat utilization

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Increment of peat utilization that started in 1990 continued also in 1991, due to which new record was achieved. Peat delivery increased 11.2 % from 16.1 million m 3 in 1990 to 17.9 million m 3 in 1991. The portion of energy peat was 16.4 million m 3 , and the portion of peat for other purposes 1.5 million m 3 . The energy content of fuel peat was 15.8 TWh, of which 13.8 TWh was milled peat and 2.0 TWh sod peat. The main portion of energy peat was used in communal back-pressure power plants for production of electricity and district heat. The second largest utilizer was industry. The rests 0.3 TWh (2 %) was delivered to private small scale utilization and export. About 88 000 MWh of sod peat was exported to Sweden. The portion of horticultural peat of the peat delivered for other purposes than energy production was 662 000 m 3 , of which only 260 000 m 3 was used in Finland and 408 000 m 3 was exported. Agriculture is the main user of peat outside the energy production. Weakly humified peat was used as litter and as absorber for slurrified manure about 286 000 m 3 . The value of the deliveries of peat industry exeeded 800 million FIM, of which the portion of milled peat was about 650 million FIM, the portion of sod peat about 95 million FIM, and the portion of domestic deliveries of horticultural peat 30 million FIM. The export of peat was 36 million FIM. Peat production in 1991 was 10.605 million m 3 , which is nearly a half of the production of 1990. The decrease was caused by both poor weather of may-june 1991 and the large peat supplies from the year 1990. About 60 % of the production target of 1991 was achieved. The production of sod peat increased by over 50 % from 736 000 m 3 in 1990 to 1 147 000 m 3 in 1991

  18. ARIES-IV Nested Shell Blanket Design

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Redler, K.; Reis, E.E.; Will, R.; Cheng, E.; Hasan, C.M.; Sharafat, S.

    1993-11-01

    The ARIES-IV Nested Shell Blanket (NSB) Design is an alternate blanket concept of the ARIES-IV low activation helium-cooled reactor design. The reference design has the coolant routed in the poloidal direction and the inlet and outlet plena are located at the top and bottom of the torus. The NSB design has the high velocity coolant routed in the toroidal direction and the plena are located behind the blanket. This is of significance since the selected structural material is SiC-composite. The NSB is designed to have key high performance components with characteristic dimensions of no larger than 2 m. These components can be brazed to form the blanket module. For the diverter design, we eliminated the use of W as the divertor coating material by relying on the successful development of the gaseous divertor concept. The neutronics and thermal-hydraulic performance of both blanket concepts are similar. The selected blanket and divertor configurations can also meet all the projected structural, neutronics and thermal-hydraulics design limits and requirements. With the selected blanket and divertor materials, the design has a level of safety assurance rate of I (LSA-1), which indicates an inherently safe design

  19. The development of peat-oil (POM) and peat-alcohol (PAM) slurries as alternative fuels

    Energy Technology Data Exchange (ETDEWEB)

    Clemens, D F; Evans, G O; Harrell, P A; Whitehurst, B M

    1983-11-01

    The preparation and evaluation of peat/No. 2 fuel oil mixtures (POM) and peat/methanol mixtures (PAM) is described. POM and PAM prepared using North Carolina peat and having varied peat loadings, peat moisture contents, and peat particle sizes have been studied by measuring slurry sedimentation ratios and drain times from sedimentation tubes. The peat moisture content was particularly crucial in forming stable slurries. The effect of a variety of additives at 0.5-1.0 wt.% on sedimentation ratios, drain times, and viscosities was studied. Calorimetric studies of several PAM and POM slurries as well as preliminary combustion tests of POM slurries in a salamander burner are also reported.

  20. Land management as a factor controlling dissolved organic carbon release from upland peat soils 1: spatial variation in DOC productivity.

    Science.gov (United States)

    Yallop, A R; Clutterbuck, B

    2009-06-01

    The importance of soil storage in global carbon cycling is well recognised and factors leading to increased losses from this pool may act as a positive feedback mechanism in global warming. Upland peat soils are usually assumed to serve as carbon sinks, there is however increasing evidence of carbon loss from upland peat soils, and DOC concentrations in UK rivers have increased markedly over the past three decades. A number of drivers for increasing DOC release from peat soils have been proposed although many of these would not explain fine-scale variations in DOC release observed in many catchments. We examined the effect of land use and management on DOC production in upland peat catchments at two spatial scales within the UK. DOC concentration was measured in streams draining 50 small-scale catchments (b3 km2) in three discrete regions of the south Pennines and one area in the North Yorkshire Moors. Annual mean DOC concentration was also derived from water colour data recorded at water treatment works for seven larger scale catchments (1.5-20 km2) in the south Pennines. Soil type and land use/management in all catchments were characterised from NSRI digital soil data and ortho-corrected colour aerial imagery. Of the factors assessed, representing all combinations of soil type and land use together with catchment slope and area, the proportion of exposed peat surface resulting from new heather burning was consistently identified as the most significant predictor of variation in DOC concentration. This relationship held across all blanket peat catchments and scales. We propose that management activities are driving changes in edaphic conditions in upland peat to those more favourable for aerobic microbial activity and thus enhance peat decomposition leading to increased losses of carbon from these environments.

  1. Peat production. Review of research projects; Turvetuotanto. Tutkimusalueen katsaus

    Energy Technology Data Exchange (ETDEWEB)

    Leinonen, A. [VTT Energy, Jyvaeskylae (Finland)

    1997-12-01

    The development target in the research area of peat production is to improve the competitiveness of peat by reducing production costs by 20 % (by FIM 5 - 6/MWh) from the level of the year 1992 and to reduce environmental impacts. The most important research objects by which the target in peat production technology will be achieved are drawing and preparation technology, drying technology, mechanical technology, method technology, integration of wood harvesting and peat production, and the application of the results of the OPTIMITURVE Research Programme in practice. (orig.)

  2. Fusion blanket inherent safety assessment

    International Nuclear Information System (INIS)

    Sze, D.K.; Jung, J.; Cheng, E.T.

    1986-01-01

    Fusion has significant potential safety advantages. There is a strong incentive for designing fusion plants to ensure that inherent safety will be achieved. Accordingly, both the Tokamak Power Systems Studies and MINIMARS have identified inherent safety as a design goal. A necessary condition is for the blanket to maintain its configuration and integrity under all credible accident conditions. A main problem is caused by afterheat removal in an accident condition. In this regard, it is highly desirable to achieve the required level of protection of the plant capital investment and limitation of radioactivity release by systems that rely only on inherent properties of matter (e.g., thermal conductivity, specific heat, etc.) and without the use of active safety equipment. This paper assesses the conditions under which inherent safety is feasible. Three types of accident conditions are evaluated for two blankets. The blankets evaluated are a self cooled vanadium/lithium blanket and a self-cooled vanadium/Flibe blanket. The accident conditions evaluated are: (1) loss-of-flow accident; (2) loss-of-coolant accident (LOCA); and (3) partial loss-of-coolant accident

  3. Life-cycle of fuel peat

    International Nuclear Information System (INIS)

    Leijting, J.; Silvo, K.

    1998-01-01

    The share of peat in the primary energy supply in Finland in 1996 was about 6.5 % and the area used for peat production was about 535 km 2 , corresponding to about 0.5 % of the original peatland area of Finland. Fuel peat production is hence a significant form of using natural resources. About 1.4 % of the total peatland area has been reserved for peat production. Approximately 95 % of the peat excavated in Finland is used as fuel peat, and 5 % as horticultural peat. As raw material and fuel peat can be considered to be slowly renewable material. The environmental impacts of fuel peat production, transportation and peat combustion were evaluated in this research by methods used in life-cycle assessment. Preparation and production phases of peat production areas, fuel peat transportation to power plants, combustion of peat in power plants, and disposal of the ashes formed the basis for the investigation. Data collected in 1994-1996 was used as the basic material in the research. Special attention was paid to the estimation of greenhouse gas balance when using a virgin bog and the forest drained peatland areas as starting points. Post-production use of peatlands were not inspected in the life-cycle assessment. The work was carried out in 1997 in cooperation with Vapo Oy. The regional environmental centers, VTT and Helsinki and Joensuu Universities assisted significantly in acquisition of the material and planning of the work 3 refs

  4. PDF -- new peat technology

    Energy Technology Data Exchange (ETDEWEB)

    Myreen, P B

    1982-12-01

    The impact of a large-scale utilization of peat must be assessed in each region separately. As it is completely impractical to transport wet peat over long distances, a PDF plant must be built in the peatland region. Such regions often need economic stimulation. The PDF process can be run independent of season and weather, and thus offers permanent jobs. Dredging the peat layer all at once in a wet state is an operation concentrated on a very small land area. If this area can be drained, it can soon afterwards be forested or used for agricultural purposes. Even if the area from which the peat is removed is left as a wetland, when cleverly done, the ecological effects may be favourable. Peat is a significant energy source in many countries now looking for domestic alternatives to expensive imported fuels. The main constraint on large-scale utilization of peat is its ability to retain moisture. The wet-carbonization process, utilized in a PDF plant and yielding a high-quality peat-derived fuel, is believed to be a technically feasible and economically attractive industrial method of dewatering native peat.

  5. Blanket Manufacturing Technologies : Thermomechanical Tests on HCLL Blanket Mocks Up

    International Nuclear Information System (INIS)

    Laffont, G.; Cachon, L.; Taraud, P.; Challet, F.; Rampal, G.; Salavy, J.F.

    2006-01-01

    In the Helium Cooled Lithium Lead (HCLL) Blanket concept, the lithium lead plays the double role of breeder and multiplier material, and the helium is used as coolant. The HCCL Blanket Module are made of steel boxes reinforced by stiffening plates. These stiffening plates form cells in which the breeder is slowly flowing. The power deposited in the breeder material is recovered by the breeder cooling units constituted by 5 parallel cooling plates. All the structures such as first wall, stiffening and cooling plates are cooled by helium. Due to the complex geometry of these parts and the high level of pressure and temperature loading, thermo-mechanical phenomena expected in the '' HCLL blanket concept '' have motivated the present study. The aim of this study, carried out in the frame of EFDA Work program, is to validate the manufacturing technologies of HCLL blanket module by testing small scale mock-up under breeder blanket representative operating conditions.The first step of this experimental program is the design and manufacturing of a relevant test section in the DIADEMO facility, which was recently upgraded with an He cooling loop (pressure of 80 bar, maximum temperature of 500 o C,flow rate of 30 g/s) taking the opportunity of synergies with the gas-cooled fission reactor R-and-D program. The second step will deal with the thermo-mechanical tests. This paper focuses on the program made to support the cooling plate mock up tests which will be carried out on the DIADEMO facility (CEA) by thermo-mechanical calculations in order to define the relevant test conditions and the experimental parameters to be monitored. (author)

  6. Water Level and Fire Regulate Carbon Sequestration in a Subtropical Peat Marsh

    Science.gov (United States)

    Graham, S.; Sumner, D.; Shoemaker, B.; Benscoter, B.; Hinkle, C. R.

    2014-12-01

    Managed wetlands provide valuable ecosystem services, including carbon storage. Management practices, such as water-level manipulation and prescribed fire, can have a profound effect on the carbon dynamics of these ecosystems. Fluxes of carbon dioxide have been measured by eddy covariance methods over a subtropical peat marsh in Florida, USA since 2009. During this 5-year period, the site has experienced hydroperiods ranging from nine to twelve months. Hydroperiod was found to affect net ecosystem productivity, which was relatively low (70-130 grams carbon per square meter) in years with periodic drying events and much higher (300-600 grams carbon per square meter) during years with constant marsh inundation. The site experienced a prescribed fire in Spring of 2014, which consumed approximately 80% of the aboveground biomass (800 grams carbon per square meter). In addition to the carbon released by the fire, photosynthetic uptake during what would normally be the most productive part of the year was reduced relative to previous years due to low leaf area. These results illustrate how management practices can affect carbon sequestration, which is important for both atmospheric greenhouse gas concentrations and maintenance of peat topography.

  7. Biochemical processes of oligotrophic peat deposits of Vasyugan Mire

    Science.gov (United States)

    Inisheva, L. I.; Sergeeva, M. A.

    2009-04-01

    The problem of peat and mire ecosystems functioning and their rational use is the main problem of biosphere study. This problem also refers to forecasting of biosphere changes results which are global and anthropogenic. According to many scientists' research the portion of mires in earth carbon balance is about 15% of world's stock. The aim of this study is to investigate biochemical processes in oligotrophic deposits in North-eastern part of Vasyugan Mire. The investigations were made on the territory of scientific-research ground (56˚ 03´ and 56˚ 57´ NL, 82˚ 22´ and 82˚ 42´ EL). It is situated between two rivers Bakchar and Iksa (in outskirts of the village Polynyanka, Bakchar region, Tomsk oblast). Evolution of investigated mire massif began with the domination of eutrophic phytocenosis - Filicinae, then sedge. Later transfer into oligotrophic phase was accompanied by formation of meter high-moor peat deposit. The age of three-meter peat deposit reaches four thousand years. Biochemical processes of carbon cycle cover the whole peat deposit, but the process activity and its direction in different layers are defined by genesis and duration of peat formation. So, the number of cellulose-fermenting aerobes in researched peat deposits ranges from 16.8 to 75.5 million CFU/g, and anaerobic bacteria from 9.6 to 48.6 million CFU/g. The high number of aerobes is characteristic for high water levels, organizing by raised bog peats. Their number decreases along the profile in 1.7 - 2 times. The number of microflora in peat deposit is defined by the position in the landscape profile (different geneses), by the depth, by hydrothermic conditions of years and individual months. But microflora activity shows along all depth of peat deposit. We found the same in the process of studying of micromycete complex structure. There was revealed either active component micromycete complex - mycelium, or inert one - spores in a meter layer of peat deposit. If mushrooms

  8. Canadian peat harvesting and the environment

    International Nuclear Information System (INIS)

    Keys, D.

    1992-01-01

    In 1990, ca 749,000 tonnes of peat were sold by Canadian producers, a small volume in comparison to the estimated 50 million tonnes or more that accumulate naturally each year in Canada. Most of the harvested peat was used for horticultural purposes. The relationship between peatlands and the peat industry is examined, and issues related to the environment and sustainable resource use are discussed. Case studies are used to examine several specific situations where peatland development proposals have undergone environmental assessments. The present status of peatland conservation in Canada is reviewed. To date, developed peatlands are primarily situated in the boreal wetland regions and consist mainly of the bog wetland class. Environmental issues related to peatland development include the need for conservation of flora, fauna, and other ecological values or functions. The potential for release of carbon gases due to Canadian peat harvesting is considered to be insignificant in relation to other uses of carbon sources such as the combustion of fossil fuel, and is unlikely to influence global warming at the present or projected levels of peatland development in Canada. The influence and mitigation of the effects of drainage of peatlands for peat production on water quality and flow regime are being addressed on a site-specific basis through existing regulatory procedures and research. Reclamation and restoration options are being incorporated during design and operational development of new peat harvesting areas. 39 refs., 15 figs., 3 tabs

  9. Growing peat

    NARCIS (Netherlands)

    Harpenslager, S.F.

    2015-01-01

    Peat formation is a slow process and the formation of thick peat layers in large parts of e.g. Russia, Canada and Indonesia has generally taken thousands of years. Due to degradation of peatlands throughout the world, as a result of changed land use and pollution, many ecosystem services provided by

  10. NET test blanket design and remote maintenance

    International Nuclear Information System (INIS)

    Holloway, C.; Hubert, P.

    1991-01-01

    The NET machine has three horizontal ports reserved for testing tritium breeding blanket designs during the physics phase and possibly five during the technology phase. The design of the ports and test blankets are modular to accept a range of blanket options, provide radiation shielding and allow routine replacement. Radiation levels during replacement or maintenance require that all operations must be carried out remotely. The paper describes the problems overcome in providing a port design which includes attachment to the vacuum vessel with double vacuum seals, an integrated cooled first wall and support guides for the test blanket module. The method selected to remotely replace the test module whilst controlling the spread of contamination is also adressed. The paper concludes that the provisions of a test blanket facility based on the NET machine design is feasible. (orig.)

  11. Three-dimensional distribution of organic matter in coastal-deltaic peat : Implications for subsidence and carbon dioxide emissions by human-induced peat oxidation

    NARCIS (Netherlands)

    Koster, K.; Stafleu, J.; Cohen, K. M.; Stouthamer, E.; Busschers, Freek S.; Middelkoop, H.

    2018-01-01

    Human-induced groundwater level lowering in the Holocene coastal-deltaic plain of the Netherlands causes oxidation of peat organic matter, resulting in land subsidence and carbon dioxide (CO2) emissions. Here, a three-dimensional (3D) analysis of the distribution of the remaining peat organic matter

  12. Exploring climatic controls on blanket bog litter decomposition across an altitudinal gradient

    Science.gov (United States)

    Bell, Michael; Ritson, Jonathan P.; Clark, Joanna M.; Verhoef, Anne; Brazier, Richard E.

    2016-04-01

    through measurements of N content in Sphagnum capitula), but this conclusion raises new questions over the reasons for, and the likely resilience of, the greater sink at the higher elevation sites relative to those at lower elevations. This talk disentangles the effects of temperature, moisture and N deposition on blanket bog litter decomposition, in order to make predictions about the future C balance of bogs in these areas that are climatically marginal in terms of peat bog formation.

  13. The sustainable use of peat

    International Nuclear Information System (INIS)

    Kallas, Rein

    1997-01-01

    The article gives information about the critical and usable reserves of peat, its annual consumption and production allowance, as well as the output in 1996. It is seen from the Table that no increase in peat production is possible in the counties of Paernu and Rapla, as well as in western Estonia unless the exhausted peat fields have been reclaimed, so, after the limit has been released. However, conditions for peat production in southern Estonia are favourable. The low peat production capacity, 1 million t, while the production quota is 2.78 million t, is indicative of the depression of Estonian peat industry. (author)

  14. The history of the peat manufacturing industry in The Netherlands: Peat moss litter and active carbon

    Directory of Open Access Journals (Sweden)

    M.A.W. Gerding

    2015-11-01

    Full Text Available This article describes the development of three major forms of peat processing by the manufacturing industry in The Netherlands since the last quarter of the 19th century. At a time when peat as a fuel was gradually being replaced by coal, the first form was the peat moss litter industry. Peat moss litter was made from white peat that was ground and sieved in factories which were located mainly in bog areas in the south-east of the province of Drenthe. It served as excellent bedding for horses and cattle. The second form of industrial peat processing was the manufacture, from 1921 onwards, of active carbon made from black peat. The Purit (Norit factory, now part of the Cabot Corporation, is still the only active carbon factory using peat as a raw material. The third form of peat processing was the production of garden peat and potting soil. This is still a widespread activity in peat areas all over the world. The peat moss litter industry thrived from the 1880s until shortly after the First World War. The arrival of the horse-drawn tram in all of the major cities of Europe created a great demand for animal bedding to be used in the vast stables of the tramway companies. Peat moss litter was cleaner, healthier and easier to handle than straw. There was similar demand from the armies, which used millions of horses during the First World War. Owing to the development of motorised vehicles, the peat market collapsed after the war and this plunged the industry into a prolonged crisis which was not overcome until peat was found to be a suitable growing medium for horticulture in the 1950s. Living and working conditions in peatlands were harsh, earnings irregular and labourers’ rights limited. The peat manufacturing industry was the first to introduce collective labour agreements, medical benefits and pension plans. Nonetheless massive unemployment, poverty and the necessity to migrate to other parts of the country were clear signs that the era of

  15. Workshop on cold-blanket research

    International Nuclear Information System (INIS)

    1977-05-01

    The objective of the workshop was to identify and discuss cold-plasma blanket systems. In order to minimize the bombardment of the walls by hot neutrals the plasma should be impermeable. This requires a density edge-thickness product of nΔ > 10 15 cm -2 . An impermeable cold plasma-gas blanket surrounding a hot plasma core reduces the plasma wall/limiter interaction. Accumulation of impurities in this blanket can be expected. Fuelling from a blanket may be possible as shown by experimental results, though not fully explained by classical transport of neutrals. Refuelling of a reacting plasma had to be ensured by inward diffusion. Experimental studies of a cold impermeable plasma have been done on the tokamak-like Ringboog device. Simulation calculations for the next generation of large tokamaks using a particular transport model, indicate that the plasma edge profile can be controlled to reduce the production of sputtered impurities to an acceptable level. Impurity control requires a small fraction of the radial space to accomodate the cold-plasma layer. The problem of exhaust is, however, more complicated. If the cold-blanket scheme works as predicted in the model calculations, then α-particles generated by fusion will be transported to the cold outside layer. The Communities' experimental programme of research has been discussed in terms of the tokamaks which are available and planned. Two options present themselves for the continuation of cold-blanket research

  16. Joint Markov Blankets in Feature Sets Extracted from Wavelet Packet Decompositions

    Directory of Open Access Journals (Sweden)

    Gert Van Dijck

    2011-07-01

    Full Text Available Since two decades, wavelet packet decompositions have been shown effective as a generic approach to feature extraction from time series and images for the prediction of a target variable. Redundancies exist between the wavelet coefficients and between the energy features that are derived from the wavelet coefficients. We assess these redundancies in wavelet packet decompositions by means of the Markov blanket filtering theory. We introduce the concept of joint Markov blankets. It is shown that joint Markov blankets are a natural extension of Markov blankets, which are defined for single features, to a set of features. We show that these joint Markov blankets exist in feature sets consisting of the wavelet coefficients. Furthermore, we prove that wavelet energy features from the highest frequency resolution level form a joint Markov blanket for all other wavelet energy features. The joint Markov blanket theory indicates that one can expect an increase of classification accuracy with the increase of the frequency resolution level of the energy features.

  17. Fourth technical contractors' conference on peat

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    This conference reported the status of the US Department of Energy Peat Program. The papers presented dealt with peat dewatering, international peat programs, environmental and socio-economic factors, peat gasification, peat harvesting, and the state peat surveys for 14 states. Separate abstracts were prepared for the individual papers. (CKK)

  18. Materials for breeding blankets

    International Nuclear Information System (INIS)

    Mattas, R.F.; Billone, M.C.

    1995-09-01

    There are several candidate concepts for tritium breeding blankets that make use of a number of special materials. These materials can be classified as Primary Blanket Materials, which have the greatest influence in determining the overall design and performance, and Secondary Blanket Materials, which have key functions in the operation of the blanket but are less important in establishing the overall design and performance. The issues associated with the blanket materials are specified and several examples of materials performance are given. Critical data needs are identified

  19. Materials for breeding blankets

    International Nuclear Information System (INIS)

    Mattas, R.F.; Billone, M.C.

    1996-01-01

    There are several candidate concepts for tritium breeding blankets that make use of a number of special materials. These materials can be classified as primary blanket materials, which have the greatest influence in determining the overall design and performance, and secondary blanket materials, which have key functions in the operation of the blanket but are less important in establishing the overall design and performance. The issues associated with the blanket materials are specified and several examples of materials performance are given. Critical data needs are identified. (orig.)

  20. The history of the peat manufacturing industry in The Netherlands : peat moss litter and active carbon

    NARCIS (Netherlands)

    Karel, Erwin; Gerding, Michiel; De Vries, Gerben

    This article describes the development of three major forms of peat processing by the manufacturing industry in The Netherlands since the last quarter of the 19th century. At a time when peat as a fuel was gradually being replaced by coal, the first form was the peat moss litter industry. Peat moss

  1. Response of tropical peat swamp forest tree species seedlings to macro nutrients

    Directory of Open Access Journals (Sweden)

    Tri Wira Yuwati

    2015-10-01

    Full Text Available Abstract Efforts of restoration of degraded tropical peat swamp forest were facing constraints due to the low available nutrient level of peat. The transplanted peat swamp forest species seedlings experienced low survival rate and poor growth performance. This study aimed to demonstrate the response of ten tropical peat swamp forest species seedlings whether climax and pioneer species to macro-nutrients addition in the nursery. The growth performance of climax and pioneer tropical peat swamp species seedlings was recorded following addition of macro nutrients of Nitrogen (N, Phosphorus(P, Potassium(K and Dolomitic limestone (CaMg. The result showed that Alstonia spatulata and Parartocarpus venenosus showed positive growth response following macro nutrients addition. This study concluded that tropical peat swamp pioneer species has lower necessity for macro-nutrients addition than tropical peat swamp climax species.

  2. Cupriferous peat: embryonic copper ore

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, D C

    1961-07-01

    A Canadian peat was found to contain up to 10% (dry weight) Cu, and a mechanism for Cu accumulation in peat was discussed. Wet chemical techniques and x-ray diffraction were utilized to identify Cu compounds. Copper was organically bound in peat as a chelate complex and did not occur as an oxide, sulfide, or as elemental Cu. Because of the low S content of peat the Cu was assumed to be bound to nitrogen or oxygen-containing components. Copper, having a greater affinity for N, tended to form the more stable Cu-N chelate. The element was concentrated as circulating cupriferous ground waters filtered through the peat.

  3. Impact of mesh tracks and low-ground-pressure vehicle use on blanket peat hydrology

    Science.gov (United States)

    McKendrick-Smith, Kathryn; Holden, Joseph; Parry, Lauren

    2016-04-01

    Peatlands are subject to multiple uses including drainage, farming and recreation. Low-ground-pressure vehicle access is desirable by land owners and tracks facilitate access. However, there is concern that such activity may impact peat hydrology and so granting permission for track installation has been problematic, particularly without evidence for decision-making. We present the first comprehensive study of mesh track and low-ground-pressure vehicle impacts on peatland hydrology. In the sub-arctic oceanic climate of the Moor House World Biosphere Reserve in the North Pennines, UK, a 1.5 km long experimental track was installed to investigate hydrological impacts. Surface vegetation was cut and the plastic mesh track pinned into the peat surface. The experimental track was split into 7 treatments, designed to reflect typical track usage (0 - 5 vehicle passes per week) and varying vehicle weight. The greatest hydrological impacts were expected for sections of track subject to more frequent vehicle use and in close proximity to the track. In total 554 dipwells (including 15 automated recording at 15-min intervals) were monitored for water-table depth, positioned to capture potential spatial variability in response. Before track installation, samples for vertical and lateral hydraulic conductivity (Ks) analysis (using the modified cube method) were taken at 0-10 cm depth from a frequently driven treatment (n = 15), an infrequently driven treatment (0.5 passes per week) (n = 15) and a control site with no track/driving (n = 15). The test was repeated after 16 months of track use. We present a spatially and temporally rich water-table dataset from the study site showing how the impacts of the track on water table are spatially highly variable. Water-table depths across the site were shallow, typically within the upper 10 cm of the peat profile for > 75% of the time. We show that mesh track and low-ground-pressure vehicle impacts on water-table depth were small except

  4. ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS

    International Nuclear Information System (INIS)

    WONG, CPC; MALANG, S; NISHIO, S; RAFFRAY, R; SAGARA, S

    2002-01-01

    OAK A271 ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS. First wall and blanket (FW/blanket) design is a crucial element in the performance and acceptance of a fusion power plant. High temperature structural and breeding materials are needed for high thermal performance. A suitable combination of structural design with the selected materials is necessary for D-T fuel sufficiency. Whenever possible, low afterheat, low chemical reactivity and low activation materials are desired to achieve passive safety and minimize the amount of high-level waste. Of course the selected fusion FW/blanket design will have to match the operational scenarios of high performance plasma. The key characteristics of eight advanced high performance FW/blanket concepts are presented in this paper. Design configurations, performance characteristics, unique advantages and issues are summarized. All reviewed designs can satisfy most of the necessary design goals. For further development, in concert with the advancement in plasma control and scrape off layer physics, additional emphasis will be needed in the areas of first wall coating material selection, design of plasma stabilization coils, consideration of reactor startup and transient events. To validate the projected performance of the advanced FW/blanket concepts the critical element is the need for 14 MeV neutron irradiation facilities for the generation of necessary engineering design data and the prediction of FW/blanket components lifetime and availability

  5. Physical prerequisites for the development of technological systems for draining a peat bed. [Peat; USSR

    Energy Technology Data Exchange (ETDEWEB)

    Bazin, Ye T

    1981-01-01

    It is noted that at the present time, the basic peat reserve is made up primarily of the upper type of peat deposits, which are exceedingly complex for industrial development. In this regard, the development and introduction of new progressive methods for studying peat deposits, which provide for the acquisition of broad and reliable information about the composition and properties of the peat have great practical meaning. Cited in brief form are the conclusions and recommendations produced as a result of comprehensive systematic studies of the composition and properties of peat beds located in different regions of the country which were fulfilled in the KPI since 1970.

  6. CO2 efflux from cleared mangrove peat.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available CO(2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils.We measured CO(2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO(2 efflux. CO(2 efflux from soils declines from time of clearing from ∼10,600 tonnes km(-2 year(-1 in the first year to 3000 tonnes km(2 year(-1 after 20 years since clearing. Disturbing peat leads to short term increases in CO(2 efflux (27 umol m(-2 s(-1, but this had returned to baseline levels within 2 days.Deforesting mangroves that grow on peat soils results in CO(2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks.

  7. ITER blanket designs

    International Nuclear Information System (INIS)

    Gohar, Y.; Parker, R.; Rebut, P.H.

    1995-01-01

    The ITER first wall, blanket, and shield system is being designed to handle 1.5±0.3 GW of fusion power and 3 MWa m -2 average neutron fluence. In the basic performance phase of ITER operation, the shielding blanket uses austenitic steel structural material and water coolant. The first wall is made of bimetallic structure, austenitic steel and copper alloy, coated with beryllium and it is protected by beryllium bumper limiters. The choice of copper first wall is dictated by the surface heat flux values anticipated during ITER operation. The water coolant is used at low pressure and low temperature. A breeding blanket has been designed to satisfy the technical objectives of the Enhanced Performance Phase of ITER operation for the Test Program. The breeding blanket design is geometrically similar to the shielding blanket design except it is a self-cooled liquid lithium system with vanadium structural material. Self-healing electrical insulator (aluminum nitride) is used to reduce the MHD pressure drop in the system. Reactor relevancy, low tritium inventory, low activation material, low decay heat, and a tritium self-sufficiency goal are the main features of the breeding blanket design. (orig.)

  8. Non-destructive methods for peat layer assessment in oligotrophic peat bogs: a case study from Poiana Ştampei, Romania

    Directory of Open Access Journals (Sweden)

    Iuliana F. Gheorghe

    2011-01-01

    Full Text Available Practices currently employed in the investigation and characterisation of peat deposits are destructive and may irremediable perturb peat bog development even in cases when exploitation is not carried out. We investigated the correlation between vegetation characteristics in the active area of Poiana Ştampei peat bog, Romania, and the underlying peat layer depth, aiming at establishing a non-destructive method of peat layer depth estimation. The presence of the Sphagneto-Eriophoretum vaginati association, dominated by Sphagnum fimbriatum, Eriophorum vaginatum, Andromeda polifolia, Vaccinium oxycoccos, V. myrtillus, V. vitis-idaea, Polytrichum commune, Picea excelsa, Pinus sylvestris and Betula verrucosa was found to predict the existence of the peat layer but not its depth. Out of the seven identified vegetation types, one type was associated with a very thin or no peat layer, one type was characterised by the presence of a thick (over 100 cm peat layer and five types indicated the presence of variable average depths of the peat layer. pH values correlated with peat layer depth only within the vegetation type associated with thick peat layers.

  9. ITER convertible blanket evaluation

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Cheng, E.

    1995-01-01

    Proposed International Thermonuclear Experimental Reactor (ITER) convertible blankets were reviewed. Key design difficulties were identified. A new particle filter concept is introduced and key performance parameters estimated. Results show that this particle filter concept can satisfy all of the convertible blanket design requirements except the generic issue of Be blanket lifetime. If the convertible blanket is an acceptable approach for ITER operation, this particle filter option should be a strong candidate

  10. Advanced high performance solid wall blanket concepts

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Malang, S.; Nishio, S.; Raffray, R.; Sagara, A.

    2002-01-01

    First wall and blanket (FW/blanket) design is a crucial element in the performance and acceptance of a fusion power plant. High temperature structural and breeding materials are needed for high thermal performance. A suitable combination of structural design with the selected materials is necessary for D-T fuel sufficiency. Whenever possible, low afterheat, low chemical reactivity and low activation materials are desired to achieve passive safety and minimize the amount of high-level waste. Of course the selected fusion FW/blanket design will have to match the operational scenarios of high performance plasma. The key characteristics of eight advanced high performance FW/blanket concepts are presented in this paper. Design configurations, performance characteristics, unique advantages and issues are summarized. All reviewed designs can satisfy most of the necessary design goals. For further development, in concert with the advancement in plasma control and scrape off layer physics, additional emphasis will be needed in the areas of first wall coating material selection, design of plasma stabilization coils, consideration of reactor startup and transient events. To validate the projected performance of the advanced FW/blanket concepts the critical element is the need for 14 MeV neutron irradiation facilities for the generation of necessary engineering design data and the prediction of FW/blanket components lifetime and availability

  11. Influence of the Chernobyl accident on radioactivity of fuel peat and peat ash in Finland

    International Nuclear Information System (INIS)

    Mustonen, R.; Salonen, S.; Itkonen, A.

    1988-04-01

    The accident at the Chernobyl nuclear power plant in April 1986 caused very uneven deposition of radionuclides in Finland. The deposited radionuclides were measured in relative high concentrations in fuel peat and especially in peat ash. The radionuclide concentrations were measured at six peat-fired power plants in different parts of Finland throughout the heating season 1986-87. Also evaporation of different radionuclides in peat combustion and their condensation on fly ash particles were studied at four power plants. The 137 Cs-concentrations in compiled peat samples varied between 30 and 3600 Bq kg -1 dry weight and in ash samples between 600 and 68000 Bq kg -1 . Differences in radionuclide concentrations between the power plants were great and also the radionuclide composition in fuel peat varied regionally. The 137 Cs-concentrations of the fly ash after the ash precipitators varied between 12000 and 120000 Bq kg -1 and fly ash emissions varied from 17 to 1100 mg m -3 , depending on the power plant and the load of the boiler. High radioactivity concentrations in precipitator ash caused some restrictions to the utilization of peat ash for various purposes

  12. Precipitation-induced runoff and leaching from milled peat mining mires by peat types : a comparative method for estimating the loading of water bodies during peat pruduction

    OpenAIRE

    Svahnbäck, Lasse

    2007-01-01

    Precipitation-induced runoff and leaching from milled peat mining mires by peat types: a comparative method for estimating the loading of water bodies during peat production. This research project in environmental geology has arisen out of an observed need to be able to predict more accurately the loading of watercourses with detrimental organic substances and nutrients from already existing and planned peat production areas, since the authorities capacity for insisting on such predicti...

  13. Peat-accumulating depositional systems of Sarawak, East Malaysia

    Science.gov (United States)

    Staub, James R.; Esterle, Joan S.

    1994-02-01

    Many coal deposits originate in deltaic, estuarine, and coastal plain settings and a knowledge of interrelationships between the tectonic and depositional elements active at the time of sediment deposition is necessary to formulate basin scale models. The prograding coastal depositional systems of Sarawak all contain domed peat-accumulating environments in which low-ash, low-sulfur peats are being deposited in areas of active clastic siliciclastic sedimentation. These depositional systems are as large as 11,400 km 2 and individual peat deposits within systems are in excess of 20 m thick and 1000 km 2 in area. The geographic positions and drainage basin areas of each depositional system are controlled by fault and fold systems. Although prograding into the same receiving basin, individual system geomorphology is variable and ranges from a wave-dominated microtidal delta, to a wave-dominated meso- to macro-tidal delta/coastal plain system, to a tide-dominated macrotidal estuarine embayment along a 450 km stretch of coastline. System variation is a function of sediment supply, shelf and embayment geometry, wave climate, and tidal range. These factors, which control depositional system geomorphology, also control the resulting long axis orientation of the thick, domed peat deposits. The surface vegetation and internal characteristics of most domed peat deposits, however, are similar. Internal characteristics consist of basal high-ash, high-sulfur, degraded peats overlain by low-ash, low-sulfur, well preserved peats in vertical profile. These systems demonstrate variable responses to late Pleistocene/Holocene sea-level rise and, in these instances, the variation is most attributable to local differences in siliciclastic sediment supply, which is a function of the drainage basin area.

  14. Third technical contractors' conference on peat

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The conference dealt with the estimation of US peat reserves, methods for the gasification of peat, including biogasification, techniques for dewatering peat, and the harvesting of peat. Separate abstracts were prepared for the individual papers. (CKK)

  15. Blanket testing in NET

    International Nuclear Information System (INIS)

    Chazalon, M.; Daenner, W.; Libin, B.

    1989-01-01

    The testing stages in NET for the performance assessment of the various breeding blanket concepts developed at the present time in Europe for DEMO (LiPb and ceramic blankets) and the requirements upon NET to perform these tests are reviewed. Typical locations available in NET for blanket testing are the central outboard segments and the horizontal ports of in-vessel sectors. These test positions will be connectable with external test loops. The number of test loops (helium, water, liquid metal) will be such that each major class of blankets can be tested in NET. The test positions, the boundary conditions and the external test loops are identified and the requirements for test blankets are summarized (author). 6

  16. Aerial photography in peat production technology

    International Nuclear Information System (INIS)

    Tervo, M.

    1998-01-01

    In this project, possibilities of using aerial photography in peat technology were studied experimentally, the frequency of self-heating in peat stockpiles was surveyed and the effect of compacting on the inner temperature in a self-heated milled peat stockpile was studied. Air photographs can be used in several sub-fields of the peat production. On the basis of these photos it is possible to draw conclusions from the environmental impacts of peat production, from conditions in the peat field, and from qualitative and moisture differences of surface peat. In addition, aerial photography can be utilised in updating bog maps. On the basis of aerial thermal photography in autumns 1987 - 1993, 29 % of milled peat stockpiles, and 4 % of sod peat stockpiles were found to be self-heated. The susceptibility to self-heating varied at different peatlands. The effect of compacting with a bulldozer was studied at three self-heated test stock-piles, two of which were compacted. The inner temperatures in the test stockpiles decreased significantly over the three-month monitoring period. The falls in the inner temperature of all three stockpiles were identical. Compacting did not have any significant effect on the temperature fall or on the rate of fall. The number of test stockpiles (3) is insufficient to give any statistical reliability. (orig.)

  17. Soil carbon dioxide emissions from a rubber plantation on tropical peat.

    Science.gov (United States)

    Wakhid, Nur; Hirano, Takashi; Okimoto, Yosuke; Nurzakiah, Siti; Nursyamsi, Dedi

    2017-03-01

    Land-use change in tropical peatland potentially results in a large amount of carbon dioxide (CO 2 ) emissions owing to drainage, which lowers groundwater level (GWL) and consequently enhances oxidative peat decomposition. However, field information on carbon balance is lacking for rubber plantations, which are expanding into Indonesia's peatlands. To assess soil CO 2 emissions from an eight-year-old rubber plantation established on peat after compaction, soil CO 2 efflux was measured monthly using a closed chamber system from December 2014 to December 2015, in which a strong El Niño event occurred, and consequently GWL lowered deeply. Total soil respiration (SR) and oxidative peat decomposition (PD) were separately quantified by trenching. In addition, peat surface elevation was measured to determine annual subsidence along with GWL. With GWL, SR showed a negative logarithmic relationship (p0.05). Peat surface elevation varied seasonally in almost parallel with GWL. After correcting for GWL difference, annual total subsidence was determined at 5.64±3.20 and 5.96±0.43cmyr -1 outside and inside the trenching, respectively. Annual subsidence only through peat oxidation that was calculated from the annual PD, peat bulk density and peat carbon content was 1.50cmyr -1 . As a result, oxidative peat decomposition accounted for 25% of total subsidence (5.96cmyr -1 ) on average on an annual basis. The contribution of peat oxidation was lower than those of previous studies probably because of compaction through land preparation. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Halogens in pore water of peat bogs – the role of peat decomposition and dissolved organic matter

    Directory of Open Access Journals (Sweden)

    H. Biester

    2006-01-01

    Full Text Available Halogens are strongly enriched in peat and peatlands and such they are one of their largest active terrestrial reservoir. The enrichment of halogens in peat is mainly attributed to the formation of organohalogens and climatically controlled humification processes. However, little is known about release of halogens from the peat substrate and the distribution of halogens in the peat pore water. In this study we have investigated the distribution of chlorine, bromine and iodine in pore water of three pristine peat bogs located in the Magellanic Moorlands, southern Chile. Peat pore waters were collected using a sipping technique, which allows in situ sampling down to a depth greater than 6m. Halogens and halogen species in pore water were determined by ion-chromatography (IC (chlorine and IC-ICP-MS (bromine and iodine. Results show that halogen concentrations in pore water are 15–30 times higher than in rainwater. Mean concentrations of chlorine, bromine and iodine in pore water were 7–15 mg l−1, 56–123 μg l−1, and 10–20 μg l−1, which correspond to mean proportions of 10–15%, 1–2.3% and 0.5–2.2% of total concentrations in peat, respectively. Organobromine and organoiodine were the predominant species in pore waters, whereas chlorine in pore water was mostly chloride. Advection and diffusion of halogens were found to be generally low and halogen concentrations appear to reflect release from the peat substrate. Release of bromine and iodine from peat depend on the degree of peat degradation, whereas this relationship is weak for chlorine. Relatively higher release of bromine and iodine was observed in less degraded peat sections, where the release of dissolved organic carbon (DOC was also the most intensive. It has been concluded that the release of halogenated dissolved organic matter (DOM is the predominant mechanism of iodine and bromine release from peat.

  19. Peat Soil Stabilization using Lime and Cement

    Directory of Open Access Journals (Sweden)

    Mohd Zambri Nadhirah

    2018-01-01

    Full Text Available This paper presents a study of the comparison between two additive Lime and Cement for treating peat soil in term of stabilization. Peat and organic soils are commonly known for their high compressibility, extremely soft, and low strength. The aim of this paper is to determine the drained shear strength of treated peat soil from Perlis for comparison purposes. Direct Shear Box Test was conducted to obtain the shear strength for all the disturbed peat soil samples. The quick lime and cement was mixed with peat soil in proportions of 10% and 20% of the dry weight peat soil. The experiment results showed that the addition of additives had improved the strength characteristics of peat soil by 14% increment in shear strength. In addition, the mixture of lime with peat soil yield higher result in shear strength compared to cement by 14.07% and 13.5% respectively. These findings indicate that the lime and cement is a good stabilizer for peat soil, which often experienced high amount of moisture content.

  20. Peat Soil Stabilization using Lime and Cement

    Science.gov (United States)

    Zambri, Nadhirah Mohd; Ghazaly, Zuhayr Md.

    2018-03-01

    This paper presents a study of the comparison between two additive Lime and Cement for treating peat soil in term of stabilization. Peat and organic soils are commonly known for their high compressibility, extremely soft, and low strength. The aim of this paper is to determine the drained shear strength of treated peat soil from Perlis for comparison purposes. Direct Shear Box Test was conducted to obtain the shear strength for all the disturbed peat soil samples. The quick lime and cement was mixed with peat soil in proportions of 10% and 20% of the dry weight peat soil. The experiment results showed that the addition of additives had improved the strength characteristics of peat soil by 14% increment in shear strength. In addition, the mixture of lime with peat soil yield higher result in shear strength compared to cement by 14.07% and 13.5% respectively. These findings indicate that the lime and cement is a good stabilizer for peat soil, which often experienced high amount of moisture content.

  1. Fusion reactor blanket-main design aspects

    International Nuclear Information System (INIS)

    Strebkov, Yu.; Sidorov, A.; Danilov, I.

    1994-01-01

    The main function of the fusion reactor blanket is ensuring tritium breeding and radiation shield. The blanket version depends on the reactor type (experimental, DEMO, commercial) and its parameters. Blanket operation conditions are defined with the heat flux, neutron load/fluence, cyclic operation, dynamic heating/force loading, MHD effects etc. DEMO/commercial blanket design is distinguished e.g. by rather high heat load and neutron fluence - up to 100 W/cm 2 and 7 MWa/m 2 accordingly. This conditions impose specific requirements for the materials, structure, maintenance of the blanket and its most loaded components - FW and limiter. The liquid Li-Pb eutectic is one of the possible breeder for different kinds of blanket in view of its advantages one of which is the blanket convertibility that allow to have shielding blanket (borated water) or breeding one (Li-Pb eutectic). Using Li-Pb eutectic for both ITER and DEMO blankets have been considered. In the conceptual ITER design the solid eutectic blanket was carried out. The liquid eutectic breeder/coolant is suggested also for the advanced (high parameter) blanket

  2. Limitations on blanket performance

    International Nuclear Information System (INIS)

    Malang, S.

    1999-01-01

    The limitations on the performance of breeding blankets in a fusion power plant are evaluated. The breeding blankets will be key components of a plant and their limitations with regard to power density, thermal efficiency and lifetime could determine to a large degree the attractiveness of a power plant. The performance of two rather well known blanket concepts under development in the frame of the European Blanket Programme is assessed and their limitations are compared with more advanced (and more speculative) concepts. An important issue is the question of which material (structure, breeder, multiplier, coatings) will limit the performance and what improvement would be possible with a 'better' structural material. This evaluation is based on the premise that the performance of the power plant will be limited by the blankets (including first wall) and not by other components, e.g. divertors, or the plasma itself. However, the justness of this premise remains to be seen. It is shown that the different blanket concepts cover a large range of allowable power densities and achievable thermal efficiencies, and it is concluded that there is a high incentive to go for better performance in spite of possibly higher blanket cost. However, such high performance blankets are usually based on materials and technologies not yet developed and there is a rather high risk that the development could fail. Therefore, it is explained that a part of the development effort should be devoted to concepts where the materials and technologies are more or less in hand in order to ensure that blankets for a DEMO reactor can be developed and tested in a given time frame. (orig.)

  3. Radiocarbon dating of lowbog peat

    International Nuclear Information System (INIS)

    Trettin, R.; Hiller, A.; Mundel, G.

    1982-01-01

    Owing to complex formation conditions, the age determination of lowbog peat is generally considered difficult. Within the framework of peat profile investigations of the Havellaendisches Luch, factors that may exercise an influence on the radiocarbon concentration and disturb an ordered age sequence are discussed. With regard to lowbog peat, the interpretation of the sample material to be measured is of particular importance. (author)

  4. Fusion blanket design and optimization techniques

    International Nuclear Information System (INIS)

    Gohar, Y.

    2005-01-01

    In fusion reactors, the blanket design and its characteristics have a major impact on the reactor performance, size, and economics. The selection and arrangement of the blanket materials, dimensions of the different blanket zones, and different requirements of the selected materials for a satisfactory performance are the main parameters, which define the blanket performance. These parameters translate to a large number of variables and design constraints, which need to be simultaneously considered in the blanket design process. This represents a major design challenge because of the lack of a comprehensive design tool capable of considering all these variables to define the optimum blanket design and satisfying all the design constraints for the adopted figure of merit and the blanket design criteria. The blanket design techniques of the First Wall/Blanket/Shield Design and Optimization System (BSDOS) have been developed to overcome this difficulty and to provide the state-of-the-art techniques and tools for performing blanket design and analysis. This report describes some of the BSDOS techniques and demonstrates its use. In addition, the use of the optimization technique of the BSDOS can result in a significant blanket performance enhancement and cost saving for the reactor design under consideration. In this report, examples are presented, which utilize an earlier version of the ITER solid breeder blanket design and a high power density self-cooled lithium blanket design for demonstrating some of the BSDOS blanket design techniques

  5. The geology of selected peat-forming environments in temperate and tropical latitudes

    Science.gov (United States)

    Cameron, C.C.; Palmer, C.A.; Esterle, J.S.

    1990-01-01

    We studied peat in several geologic and climatic settings: (1) a glaciated terrain in cold-temperate Maine and Minnesota, U.S.A.; (2) an island in a temperate maritime climate in the Atlantic Ocean off the coast of Maine, U.S.A., where sea level is rising rapidly and changing the environment of peat accumulation; (3) swamps along the warm-temperate U.S. Atlantic and Gulf Coastal Plains, where sea level has changed often, thus creating sites for accumulation; and (4) in a tropical climate along the coast of Sarawak, Malaysia, and the delta of the Batang Hari River, Sumatra, Indonesia (Figs. 1 and 2). With the exception of the deposits on the Atlantic and Gulf Coastal Plains, most of the deposits described are domed bogs in which peat accumulation continued above the surface of the surrounding soil. The bogs of the U.S. Atlantic and Gulf Coastal Plains have almost level surfaces. All domed bogs are not entirely ombrotrophic (watered only from precipitation); multidomed bogs that rise from irregular or hilly surfaces may be crossed by streams that supply water to the bogs. The geologic processes or organic sedimentation, namely terrestrialization and paludification, are similar in all peat deposits considered here. Differences in geomorphology affecting the quantity and that quality of peat that has ash contents of less than 25%, which are desirable for commercial purposes, depend chiefly on: (1) high humidity, which is favorable to luxuriant growth of peat-forming vegetation; (2) a depositional setting that permits extensive accumulation relatively free from inorganic contamination from sea water and streams and from dust and volcanic ash; and (3) a stable regional water table that controls the rate of decomposition under aerobic conditions and protects the deposit against the ravages of fire. Differences in peat textures are due to the type of vegetation and to the degree of decomposition. The rate of decomposition is largely the result of the amount of oxidation

  6. ITER shielding blanket

    Energy Technology Data Exchange (ETDEWEB)

    Strebkov, Yu [ENTEK, Moscow (Russian Federation); Avsjannikov, A [ENTEK, Moscow (Russian Federation); Baryshev, M [NIAT, Moscow (Russian Federation); Blinov, Yu [ENTEK, Moscow (Russian Federation); Shatalov, G [KIAE, Moscow (Russian Federation); Vasiliev, N [KIAE, Moscow (Russian Federation); Vinnikov, A [ENTEK, Moscow (Russian Federation); Chernjagin, A [DYNAMICA, Moscow (Russian Federation)

    1995-03-01

    A reference non-breeding blanket is under development now for the ITER Basic Performance Phase for the purpose of high reliability during the first stage of ITER operation. More severe operation modes are expected in this stage with first wall (FW) local heat loads up to 100-300Wcm{sup -2}. Integration of a blanket design with protective and start limiters requires new solutions to achieve high reliability, and possible use of beryllium as a protective material leads to technologies. The rigid shielding blanket concept was developed in Russia to satisfy the above-mentioned requirements. The concept is based on a copper alloy FW, austenitic stainless steel blanket structure, water cooling. Beryllium protection is integrated in the FW design. Fabrication technology and assembly procedure are described in parallel with the equipment used. (orig.).

  7. Fusion fuel blanket technology

    International Nuclear Information System (INIS)

    Hastings, I.J.; Gierszewski, P.

    1987-05-01

    The fusion blanket surrounds the burning hydrogen core of a fusion reactor. It is in this blanket that most of the energy released by the nuclear fusion of deuterium-tritium is converted into useful product, and where tritium fuel is produced to enable further operation of the reactor. As fusion research turns from present short-pulse physics experiments to long-burn engineering tests in the 1990's, energy removal and tritium production capabilities become important. This technology will involve new materials, conditions and processes with applications both to fusion and beyond. In this paper, we introduce features of proposed blanket designs and update and status of international research. In focusing on the Canadian blanket technology program, we discuss the aqueous lithium salt blanket concept, and the in-reactor tritium recovery test program

  8. Second technical contractors' conference on peat

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    This conference reported the status of the US Department of Energy Peat Program. The program includes peat resource surveys of eleven states, peat gasification process and equipment studies, dewatering studies, and environmental and socioeconomic factors in the development of peat technology. Separate abstracts were prepared for selected papers. (CKK)

  9. Precipitation-induced runoff and leaching from milled peat mining mires by peat types: A comparative method for estimating the loading of water bodies during peat production

    Energy Technology Data Exchange (ETDEWEB)

    Svahnbaeck, L.

    2007-07-01

    Finland has some 10 million hectares of peatland, accounting for almost a third of its total area. Macroclimatic conditions have varied in the course of the Holocene growth and development of this peatland, and with them the habitats of the peat-forming plants. Temperatures and moisture conditions have played a significant role in determining the dominant species of mire plants growing there at any particular time, the resulting mire types and the accumulation and deposition of plant remains to form the peat. While in a natural state the mires of Finland have functioned as carbon dioxide sinks throughout the post-glacial period, but the ditching of peatland for forestry and agriculture, amounting to some 5,7 million hectares in Finland, has affected their water balance, especially over the last hundred years, and has thereby altered the quantity and species composition of the mire vegetation. The invasion of trees and woody plants to replace the typical mire plants following ditching for forestry purposes has stimulated the decomposition of the already accumulated peat and promoted the humification of the microbiologically active root system layer. The above climatic, environmental and mire development factors, together with ditching, have contributed, and continue to contribute, to the existence of peat horizons that differ in their physical and chemical properties, leading to differences in material transport between peatlands in a natural state and mires that have been ditched or prepared for forestry and peat production. Watercourse loading from the ditching of mires or their use for peat production can have detrimental effects on river and lake environments and their recreational use, especially where oxygen-consuming organic solids and soluble organic substances and nutrients are concerned. It has not previously been possible, however, to estimate in advance the watercourse loading likely to arise from ditching and peat production on the basis of the

  10. Organic matter loss from cultivated peat soils in Sweden

    Science.gov (United States)

    Berglund, Örjan; Berglund, Kerstin

    2015-04-01

    The degradation of drained peat soils in agricultural use is an underestimated source of loss of organic matter. Oxidation (biological degradation) of agricultural peat soils causes a loss of organic matter (OM) of 11 - 22 t ha-1 y-1 causing a CO2 emission of 20 - 40 t ha-1 y-1. Together with the associated N2O emissions from mineralized N this totals in the EU to about 98.5 Mton CO2 eq per year. Peat soils are very prone to climate change and it is expected that at the end of this century these values are doubled. The degradation products pollute surface waters. Wind erosion of peat soils in arable agriculture can cause losses of 3 - 30 t ha-1 y-1 peat also causing air pollution (fine organic particles). Subsidence rates are 1 - 2 cm per year which leads to deteriorating drainage effect and make peat soils below sea or inland water levels prone to flooding. Flooding agricultural peat soils is in many cases not possible without high costs, high GHG emissions and severe water pollution. Moreover sometimes cultural and historic landscapes are lost and meadow birds areas are lost. In areas where the possibility to regulate the water table is limited the mitigation options are either to increase biomass production that can be used as bioenergy to substitute some fossil fuel, try to slow down the break-down of the peat by different amendments that inhibit microbial activity, or permanent flooding. The negative effects of wind erosion can be mitigated by reducing wind speed or different ways to protect the soil by crops or fiber sheets. In a newly started project in Sweden a typical peat soil with and without amendment of foundry sand is cropped with reed canary grass, tall fescue and timothy to investigate the yield and greenhouse gas emissions from the different crops and how the sand effect the trafficability and GHG emissions.

  11. Greenhouse impact assessment of peat-based Fischer-Tropsch diesel life-cycle

    International Nuclear Information System (INIS)

    Kirkinen, Johanna; Soimakallio, Sampo; Maekinen, Tuula; Savolainen, Ilkka

    2010-01-01

    New raw materials for transportation fuels need to be introduced, in order to fight against climate change and also to cope with increasing risks of availability and price of oil. Peat has been recognised suitable raw material option for diesel produced by gasification and Fischer-Tropsch (FT) synthesis. The energy content of Finnish peat reserves is remarkable. In this study, the greenhouse impact of peat-based FT diesel production and utilisation in Finland was assessed from the life-cycle point of view. In 100 year's time horizon the greenhouse impact of peat-based FT diesel is likely larger than the impact of fossil diesel. The impact can somewhat be lowered by producing peat from the agricultural peatland (strong greenhouse gas emissions from the decaying peatlayer are avoided) with new peat production technique, and utilising the produced biomass from the after-treatment area for diesel also. If diesel production is integrated with pulp and paper mill to achieve energy efficiency benefits and if the electricity demand can be covered by zero emission electricity, the greenhouse impact of peat-based FT diesel reduces to the level of fossil diesel when agricultural peatland is used, and is somewhat higher when forestry-drained peatland is used as raw material source.

  12. Development of blanket remote maintenance system

    International Nuclear Information System (INIS)

    Kakudate, Satoshi; Nakahira, Masataka; Oka, Kiyoshi; Taguchi, Kou

    1998-01-01

    ITER in-vessel components such as blankets are scheduled maintenance components, including complete shield blanket replacement for breeding blankets. In-vessel components are activated by 14 MeV neutrons, so blanket maintenance requires remote handling equipment and tools able to handle heavy payloads of about 4 tons within a positioning accuracy of 2 mm under intense gamma radiation. To facilitate remote maintenance, blankets are segmented into 730 modules and rail-mounted vehicle remote maintenance was developed. According to the ITER R and D program, critical technology related to blanket maintenance was developed extensively through joint efforts of the Japan, EU, and U.S. home teams. This paper summarizes current blanket maintenance technology conducted by the Japan Home Team, including development of full-scale remote handling equipment and tools for blanket maintenance. (author)

  13. Development of blanket remote maintenance system

    Energy Technology Data Exchange (ETDEWEB)

    Kakudate, Satoshi; Nakahira, Masataka; Oka, Kiyoshi; Taguchi, Kou [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-04-01

    ITER in-vessel components such as blankets are scheduled maintenance components, including complete shield blanket replacement for breeding blankets. In-vessel components are activated by 14 MeV neutrons, so blanket maintenance requires remote handling equipment and tools able to handle heavy payloads of about 4 tons within a positioning accuracy of 2 mm under intense gamma radiation. To facilitate remote maintenance, blankets are segmented into 730 modules and rail-mounted vehicle remote maintenance was developed. According to the ITER R and D program, critical technology related to blanket maintenance was developed extensively through joint efforts of the Japan, EU, and U.S. home teams. This paper summarizes current blanket maintenance technology conducted by the Japan Home Team, including development of full-scale remote handling equipment and tools for blanket maintenance. (author)

  14. Tritium breeding blanket

    International Nuclear Information System (INIS)

    Smith, D.; Billone, M.; Gohar, Y.; Baker, C.; Mori, S.; Kuroda, T.; Maki, K.; Takatsu, H.; Yoshida, H.; Raffray, A.; Sviatoslavsky, I.; Simbolotti, G.; Shatalov, G.

    1991-01-01

    The terms of reference for ITER provide for incorporation of a tritium breeding blanket with a breeding ratio as close to unity as practical. A breeding blanket is required to assure an adequate supply of tritium to meet the program objectives. Based on specified design criteria, a ceramic breeder concept with water coolant and an austenitic steel structure has been selected as the first option and lithium-lead blanket concept has been chosen as an alternate option. The first wall, blanket, and shield are integrated into a single unit with separate cooling systems. The design makes extensive use of beryllium to enhance the tritium breeding ratio. The design goals with a tritium breeding ratio of 0.8--0.9 have been achieved and the R ampersand D requirements to qualify the design have been identified. 4 refs., 8 figs., 2 tabs

  15. RETENTION TIME EFFECT ON METAL REMOVAL BY PEAT COLUMNS

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, E

    2007-02-28

    The potential use of a peat bed to treat the H-12 Outfall discharge to bring it to new compliance limits was previously investigated and reported utilizing a 7 hour retention time. The influence of retention time (contact time) of water with peat moss on the removal of copper from the water was investigated under laboratory conditions using vertical flow peat moss columns. Reduction of the necessary retention time has a large influence on the design sizing of any peat bed that would be constructed to treat the H-12 discharge on a full scale basis. Retention times of 5 hours, 3 hours and 1 hour were tested to determine the copper removal by the peat columns using vertical flow. Water samples were collected after 4, 8, 12, and 16 water volumes had passed through the columns and analyzed for a suite of metals, with quantitative emphasis on copper. Laboratory results indicated that copper removal was very high at each of the 3 retention times tested, ranging from 99.6 % removal at 5 and 3 hours to 98.8% removal at 1 hour. All these values are much lower that the new compliance limit for the outfall. The results also indicated that most divalent metals were removed to their normal reporting detection limit for the analytical methods used, including zinc. Lead levels in the H-12 discharge used in this study were below PQL in all samples analyzed. While each of the retention times studied removed copper very well, there were indications that 1 hour is probably too short for an operational, long-term facility. At that retention time, there was about 6% compaction of the peat in the column due to the water velocity, and this may affect long term hydraulic conductivity of the peat bed. At that retention time, copper concentration in the effluent was higher than the other times tested, although still very low. Because of the potential compacting and somewhat reduced removal efficiency at a 1 hour retention time, it would be prudent to design to at least a 3 hour retention

  16. Peat resources in Cuba

    International Nuclear Information System (INIS)

    Casanova Casanova, E.

    1996-01-01

    During the last few years the drastic cut in oil supply provoked a critical situation in Cuba. The shortage of domestic oil production and the absence of alternative energy sources, such as wide rivers and coal deposits, drove us to decide that the most promising option was to develop our huge peat deposits. However, there are problems concerning skills and finance. This report reviews the potential for peat development to date in the Cuban territory. The figures and characteristics are partly taken from the surveys done by the Russian and Cuban specialists during the 60's. There is some new data compiled from the work done more recently in some of the Cuban peat deposits. The conditions for draining and harvesting are very challenging and difficult if the peat deposits are to be developed without doing any unnecessary damage to the fragile environment of Cuban wetlands. However, if the required financing and skills are available, the work can be carried out and significant risks avoided

  17. Trophic interactions among the heterotrophic components of plankton in man-made peat pools

    Directory of Open Access Journals (Sweden)

    Michał Niedźwiecki

    2017-03-01

    Full Text Available Man-made peat pools are permanent freshwater habitats developed due to non-commercial man-made peat extraction. Yet, they have not been widely surveyed in terms of ecosystem functioning, mainly regarding the complexity of heterotrophic components of the plankton. In this study we analysed distribution and trophic interrelations among heterotrophic plankton in man-made peat pools located in different types of peatbogs. We found that peat pools showed extreme differences in environmental conditions that occurred to be important drivers of distribution of microplankton and metazooplankton. Abundance of bacteria and protozoa showed significant differences, whereas metazooplankton was less differentiated in density among peat pools. In all peat pools stress-tolerant species of protozoa and metazoa were dominant. In each peat pool five trophic functional groups were distinguished. The abundance of lower functional trophic groups (bacteria, heterotrophic nanoflagellates (HNF and ciliates feeding on bacteria and HNF was weakly influenced by environmental drivers and was highly stable in all peat pool types. Higher functional trophic groups (naupli, omnivorous and carnivorous ciliates, cladocerans, adult copepods and copepodites were strongly influenced by environmental variables and exhibited lower stability. Our study contributes to comprehensive knowledge of the functioning of peat bogs, as our results have shown that peat pools are characterized by high stability of the lowest trophic levels, which can be crucial for energy transfer and carbon flux through food webs.

  18. Role of the energy use of peat in the Finnish energy system

    International Nuclear Information System (INIS)

    2005-01-01

    The objective of this study was to combine the current knowledge of the production and use of energy peat and of the significance of peat in the Finnish energy system. The study deals with the development, current state and future prospects of the production and use of energy peat, as well as the factors that have influenced or are influencing them. The use of peat has established its position in the Finnish energy system. Peat has traditionally been well available and thus its security of supply has been considered good. It has also been regarded as a high-quality indigenous fuel. In recent years many investments have been made in power plants using indigeneous fuels and in co-use of peat and wood. In fact, the use of the peat and wood of indigeneous fuels is very closely inter-linked and their use support one another. Regionally speaking, peat consumption is highest in North Ostrobothnia and inland. The negative effects of peat use are considered to be the high carbon dioxide factor of peat combustion and in some cases the possible effects of production on the local environment. Emissions trading, which was started at the beginning of 2005, weakens the competitiveness of peat in relation to other fuels. When the value of an emission allowance rises enough, also the use of coal may become cheaper than that of peat in installations in which peat has earlier been the main fuel. As the role of peat decreases, the effects are also reflected in the production and use of peat, and in the use of wood fuels, if the supply conditions of peat, which is used as the support and mixed fuel for wood, weaken. The low production of the rainy summer of 2004, combined with the low peat storage levels, led to difficulties in peat deliveries during the winter 2004-2005, and without the milder winter and good water situation in the Nordic countries the supply of peat would not necessarily have been sufficient to cover all demand. If the current role of peat is to be maintained, the

  19. Fishery impacts of peat production

    International Nuclear Information System (INIS)

    Laine, A.; Heikkinen, K.

    1991-01-01

    The total area of Finland's peat mining areas is approx. 60 000 ha. Increase in runoff from peat mining areas and changes in the quality of the runoff water, such as rises in solid matter, humus and nutrient content, result in a higher load on the lakes and rivers downstream peat mining areas. Loading from peat mining areas has been found to increase the bacterioplankton densities and change the species composition of phytoplankton in watercourses. Periphytic biomass has increased but zooplankton biomass and diversity have decreased. Corresponding changes and decreases in the number of species have also been observed in the bottom fauna of flowing waters. The loading caused by peat mining affects the fish stocks either directly or via changes in reproduct conditions and the availability of food organisms. Direct effects can be revealed as withdrawal of fish, their weakened condition and increased susceptibility to diseases, tainting or, in the worst case, even fish kills. Both organic and inorganic solid matter loading which deposits on the bottom have the most pronounced effects on fish reproduction and bottom fauna used as their food. Soiling of nets and changes in the condition of the fishing areas have a detrimental effect on fisheries. The changes that take place in the fish stocks are affected by the nature of the water system, the size of the peat mining areas and their location within the catchment area, as well as the quantity and timing of load coming from the peat mining areas. These can be influenced through technical water protection measures

  20. Mirror reactor blankets

    International Nuclear Information System (INIS)

    Lee, J.D.; Barmore, W.L.; Bender, D.J.; Doggett, J.N.; Galloway, T.R.

    1976-01-01

    The general requirements of a breeding blanket for a mirror reactor are described. The following areas are discussed: (1) facility layout and blanket maintenance, (2) heat transfer and thermal conversion system, (3) materials, (4) tritium containment and removal, and (5) nuclear performance

  1. Tritium transport modeling at system level for the EUROfusion dual coolant lithium-lead breeding blanket

    Science.gov (United States)

    Urgorri, F. R.; Moreno, C.; Carella, E.; Rapisarda, D.; Fernández-Berceruelo, I.; Palermo, I.; Ibarra, A.

    2017-11-01

    The dual coolant lithium lead (DCLL) breeding blanket is one of the four breeder blanket concepts under consideration within the framework of EUROfusion consortium activities. The aim of this work is to develop a model that can dynamically track tritium concentrations and fluxes along each part of the DCLL blanket and the ancillary systems associated to it at any time. Because of tritium nature, the phenomena of diffusion, dissociation, recombination and solubilisation have been modeled in order to describe the interaction between the lead-lithium channels, the structural material, the flow channel inserts and the helium channels that are present in the breeding blanket. Results have been obtained for a pulsed generation scenario for DEMO. The tritium inventory in different parts of the blanket, the permeation rates from the breeder to the secondary coolant and the amount of tritium extracted from the lead-lithium loop have been computed. Results present an oscillating behavior around mean values. The obtained average permeation rate from the liquid metal to the helium is 1.66 mg h-1 while the mean tritium inventory in the whole system is 417 mg. Besides the reference case results, parametric studies of the lead-lithium mass flow rate, the tritium extraction efficiency and the tritium solubility in lead-lithium have been performed showing the reaction of the system to the variation of these parameters.

  2. Environmental organizations say no to peat

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    A group of environmental protection oriented organizations published in June 10th 1999 in Helsinki a target program for energy solutions in Finland. According to the scenarios, published in 'The Recurrent Energy Policy' (Uusiutuva energiapolitiikka) publication, it would be possible to reduce the CO 2 emissions in Finland by 40 % by the year 2030 by increasing the use of renewable energy sources, and by intensifying the use of energy. The use of peat as energy source is denied in the scenarios. According to the energy scenarios of the environmental organizations the construction of new peat condensing power plants would be denied by political decision and no such plant would be allowed to be constructed after the year 2001. The generation of condensing power by peat would be finished in 2010 as the plants become out of operation. The use of peat as a fuel in back-pressure power generation and in heating plant would diminish gradually, and it would finish totally in 2025-2030. This means that the life-cycle of fuel peat in Finland would remain to 60 years. The adequacy of industrially usable peat reserves has been estimated to be 350 - 500 years. The publication defines the power or heat generated by e.g. wood, energy-willow, biogas and peat as bioenergy, but on the other hand in the program the peat is considered to be fossil fuel, and in the table presenting the carbon dioxide emissions, the emissions of peat have been presented, as characteristic in these connections, as maximum values. The scenario study suggests the heavy increase of the use of wood, natural gas, wind power, solar energy and ground heating. The energy conservation has also high priority, as well as the increasing of the industrial back-pressure power generation based on wood fuels. According to the environmental organizations the power production based on nuclear power, coal, peat and oil, as well as the import of electric power, should be stopped in Finland. New hydroelectric power would not

  3. Physical and chemical characteristics of fibrous peat

    Science.gov (United States)

    Sutejo, Yulindasari; Saggaff, Anis; Rahayu, Wiwik; Hanafiah

    2017-11-01

    Banyuasin is one of the regency in South Sumatera which has an area of 200.000 Ha of peat land. Peat soil are characterized by high compressibility parameters and low initial shear strength. Block sampling method was used to obtain undisturbed sample. The results of this paper describe the characteristics of peat soil from physical and chemical testing. The physical and chemical characteristics of peat include water content (ω), specific gravity (Gs), Acidity (pH), unit weight (γ), and ignition loss tests. SEM and EDS test was done to determine the differences in fiber content and to analyze chemical elements of the specimen. The average results ω, Gs, and pH are 263.538 %, 1.847, and 3.353. Peat is classified in H4 (by Von Post). The results of organic content (OC), ash content (AC), and fiber content (FC) are found 78.693 %, 21.310 %, and 73.703 %. From the results of physical and chemical tests, the peat in Banyuasin is classified as fibrous peat. All the results of the characteristics and classification of fibrous peat compared with published data were close.

  4. An evaluation of fast reactor blankets

    International Nuclear Information System (INIS)

    Oosterkamp, W.J.

    1974-01-01

    A comparative study of different types of fast reactor radial blankets is presented. Included are blankets of fertile material UO 2 , THO 2 and Th-metal blankets of pure reflectors C, BeO, Ni and combinations of reflecting and fertile blankets. The results for 1000MWe cores indicate that there is no incentive to use other than fertile blankets. The most favorable fertile material is thorium due to the prospective higher price of U-233

  5. Dual coolant blanket concept

    International Nuclear Information System (INIS)

    Malang, S.; Schleisiek, K.

    1994-11-01

    A self-cooled liquid metal breeder blanket with helium-cooled first wall ('Dual Coolant Blanket Concept') for a fusion DEMO reactor is described. This is one of the four blanket concepts under development in the frame of the European fusion technology program with the aim to select in 1995 the two most promising ones for further development. Described are the design of the blankets including the ancillary loop system and the results of the theoretical and experimental work in the fields of neutronics, magnetohydrodynamics, thermohydraulics, mechanical stresses, compatibility and purification of lead-lithium, tritium control, safety, reliability, and electrically insulating coatings. The remaining open questions and the required R and D programme are identified. (orig.) [de

  6. Status of fusion reactor blanket design

    International Nuclear Information System (INIS)

    Smith, D.L.; Sze, D.K.

    1986-02-01

    The recent Blanket Comparison and Selection Study (BCSS), which was a comprehensive evaluation of fusion reactor blanket design and the status of blanket technology, serves as an excellent basis for further development of blanket technology. This study provided an evaluation of over 130 blanket concepts for the reference case of electric power producing, DT fueled reactors in both Tokamak and Tandem Mirror (TMR) configurations. Based on a specific set of reactor operating parameters, the current understanding of materials and blanket technology, and a uniform evaluation methodology developed as part of the study, a limited number of concepts were identified that offer the greatest potential for making fusion an attractive energy source

  7. A new approach for peat inventory methods; Turvetutkimusten menetelmaekehitystarkastelu

    Energy Technology Data Exchange (ETDEWEB)

    Laatikainen, M.; Leino, J.; Lerssi, J.; Torppa, J.; Turunen, J. Email: jukka.turunen@gtk.fi

    2011-07-01

    Development of the new peatland inventory method started in 2009. There was a need to investigate whether new methods and tools could be developed cost-effectively so field inventory work would more completely cover the whole peatland area and the quality and liability of the final results would remain at a high level. The old inventory method in place at the Geological Survey of Finland (GTK) is based on the main transect and cross transect approach across a peatland area. The goal of this study was to find a practical grid-based method linked to the geographic information system suitable for field conditions. the triangle-grid method with even distance between the study points was found to be the most suitable approach. A new Ramac-ground penetrating radar was obtained by the GTK in 2009, and it was concluded in the study of new peatland inventory methods. This radar model is relatively light and very suitable, for example, to the forestry drained peatlands, which are often difficult to cross because of the intensive ditch network. the goal was to investigate the best working methods for the ground penetrating radar to optimize its use in the large-scale peatland inventory. Together with the new field inventory methods, a novel interpolation-based method (MITTI) for modelling peat depths was developed. MITTI makes it possible to take advantage of all the available peat-depth data including, at the moment, aerogeophysical and ground penetrating radar measurements, drilling data and the mire outline. The characteristic uncertainties of each data type are taken into account and, in addition to the depth model itself, an uncertainty map of the model is computed. Combined with the grid-based field inventory method, this multi-approach provides better tools to more accurately estimate the peat depths, peat amounts and peat type distributions. The development of the new peatland inventory method was divided into four separate sections: (1) Development of new field

  8. Changes in vegetation, peat properties and peat accumulation in Swedish peatlands as revealed by archive data.

    Science.gov (United States)

    Schoning, Kristian; Sohlenius, Gustav

    2016-04-01

    In this investigation we have studied patterns in peat accumulation and changes in mire status since the early 1900s for two areas in Sweden. In the early 1900s the Geological Survey of Sweden collected a vast amount of peat and peatland data, including information on vegetation and land-use. We have used this archive data to evaluate changes in mire vegetation, mire wetness and surface peat properties, rates of peat accumulation, succession in young wetlands and the effects of cultivation on peatlands. In total 156 mires in an uplift area of eastern middle Sweden were included in the data-set, including both pristine mires and peatlands used for agricultural purposes. In this area new peatlands have continuously been formed during the past 7 000 years making it possible to evaluate changes in peat accumulation over time. The other study area is situated in the south Swedish Uplands where we have revisited some larger bogs. The results from our investigation show that many of the peatlands have underwent major changes since the early 1900s. In most of the small peatlands we have found important changes in vegetation where mire vegetation has been replaced by nutrient demanding and/or dry species flora while the tree stand on large mires in south Sweden have increased. In some mires humification has increased in the uppermost peat-layers and the mire surface have become drier compared to the early 1900s. In eastern middle Sweden there are indications that the peat accumulation is lower 0,5 mm/year in older peatlands compared with younger ones 1,2 mm/year, although the mire vegetation in the older peatlands is dominated by sphagnum. The peat depth of the cultivated mires in this area shows a mean decrease of 40 cm since the early 1900s.

  9. Carbon balance of rewetted and drained peat soils used for biomass production: A mesocosm study

    DEFF Research Database (Denmark)

    Karki, Sandhya; Elsgaard, Lars; Kandel, Tanka

    2016-01-01

    of lower CO2 emissions without losing agricultural land. The present study quantified the carbon balance (CO2, CH4 and harvested biomass C) of rewetted and drained peat soils under intensively managed reed canary grass (RCG) cultivation. Mesocosms were maintained at five different ground water levels (GWL......), i.e., 0, 10, 20 cm below the soil surface, representing rewetted peat soils, and 30 and 40 cm below the soil surface, representing drained peat soils. Net ecosystem exchange (NEE) of CO2 and CH4 emissions were measured during the growing period of RCG (May to September) using transparent and opaque...... closed chamber methods. The average dry biomass yield was significantly lower from rewetted peat soils (12 Mg ha−1) than drained peat soils (15 Mg ha−1). Also, CO2 fluxes of gross primary production (GPP) and ecosystem respiration (ER) from rewetted peat soils were significantly lower than drained peat...

  10. Potential Phosphorus Mobilisation in Peat Soils

    DEFF Research Database (Denmark)

    Forsmann, Ditte M.; Kjærgaard, Charlotte

    2012-01-01

    Re-establishment of wetlands on peat soils containing phosphorus bound to iron(III)-oxides can lead to an undesirable phosphorus loss to the aquatic environment due to the reductive dissolution of iron(III)-oxides. Thus it is important to be able to assess the potential phosphorus mobilisation from...... peat soils before a re-establishment takes place. The potential phosphorus mobilisation from a peat soil depends not only on the geochemical characteristics but also on the redox conditions, the hydrological regime in the area as well as the hydro-physical properties of the soil. The hypothesis...... for this study is (i) the release of phosphorus in peat is controlled by the geochemistry; (ii) the mobilisation of phosphorus is controlled by both geochemistry and hydro-physics of the soil. For this study, 10 Danish riparian lowland areas with peat soil were selected based on their geochemical characteristics...

  11. Horticultural peat markets of the world. Finnish export possibilities increasing

    International Nuclear Information System (INIS)

    Knuutinen, O.

    2000-01-01

    The statistics of 1997, collected by Turveruukki Oy, show that the horticultural peat production in Europe and Northern America is about 32.6 million m 3 /a. About 20.2 million m 3 of horticultural peat was produced in 1997 in Western Europe and about 9.5 million m 3 in Northern America. The share of Eastern Europe was 2.9 million m 3 . Production of fuel peat and horticultural peat in Europe are nearly equal, but most of the countries produce only horticultural peat. Finland, Russia, Ireland, Belorussia and Sweden are countries where the share of fuel peat is high. The largest producers of horticultural peat are Germany, Canada and Estonia. The share of these countries is about 60% of the production in Europe and Northern America. Germany and Canada do not produce fuel peat at all, and in Estonia the main portion of peat production area is aimed at horticultural production. About 1.6 million m 3 of horticultural peat was produced in Finland in 1997, corresponding to about 8% of the horticultural peat production in Europe. The share of horticultural peat has been low also in Ireland and Sweden. The main portion of the horticultural peat production in Finland is produced side by side with the fuel peat production. Horticultural peat is exported mainly as processed and sacked peat. The horticultural peat production in Western Europe is about 20 million m 3 /s. The Netherlands is a were large consumer of horticultural peat, but it has no horticultural peat production of its own. Other possible countries for export are Spain and France in Europe, and Japan

  12. Excavating and loading equipment for peat mining

    Science.gov (United States)

    Mikhailov, A. V.; Zhigulskaya, A. I.; Yakonovskaya, T. B.

    2017-10-01

    Recently, the issues of sustainable development of Russian regions, related to ensuring energy security, are more urgent than ever. To achieve sustainable development, an integrated approach to the use of local natural resources is needed. Practically in all north regions of the Russian Federation, peat as a local natural resource is widespread, which has a practical application in the area of housing services. The paper presents the evaluation of technologies for open-pit peat mining, as well as analysis of technological equipment for peat production. Special attention is paid to a question of peat materials excavating and loading. The problem of equipment selection in a peat surface mine is complex. Many features, restrictions and criteria need to be considered. Use of low and ultra-low ground pressure excavators and low ground pressure front-end loaders with full-range tires to provide the necessary floatation in the peat bog environment is offered.

  13. Solid breeder test blanket module design and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ying, A. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States)]. E-mail: ying@fusion.ucla.edu; Abdou, M. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Calderoni, P. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Sharafat, S. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Youssef, M. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); An, Z. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Abou-Sena, A. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Kim, E. [University of California Los Angeles, Los Angeles, CA 90095-1597 (United States); Reyes, S. [LANL, Livermore, CA (United States); Willms, S. [LANL, Los Alamos, NM (United States); Kurtz, R. [PNNL, Richland, WA (United States)

    2006-02-15

    This paper presents the design and analysis for the US ITER solid breeder blanket test articles. Objectives of solid breeder blanket testing during the first phase of the ITER operation focus on exploration of fusion break-in phenomena and configuration scoping. Specific emphasis is placed on first wall structural response, evaluation of neutronic parameters, assessment of thermomechanical behavior and characterization of tritium release. The tests will be conducted with three unit cell arrays/sub-modules. The development approach includes: (1) design the unit cell/sub-module for low temperature operations and (2) refer to a reactor blanket design and use engineering scaling to reproduce key parameters under ITER wall loading conditions, so that phenomena under investigation can be measured at a reactor-like level.

  14. The frost peat production; Routapalaturpeen tuotantoketjun tekniikka, talous ja ympaeristoevaikutukset

    Energy Technology Data Exchange (ETDEWEB)

    Nyroenen, T. [Vapo Oy, Jyvaeskylae (Finland); Leiviskae, V. [Oulu Univ. (Finland). Thule Inst.

    1997-12-01

    The frost peat production means the cutting of frozen peat in the winter time. The aim of this study is to test the possibilities to prolong the peat production season and to produce peat pieces for the horticultural peat industry. In the frost peat production method the frozen peat field is sawed throughout the length and breadth of by a circle saw. The sawed peat pieces are loosened from the field by a so-called `splitter`. The circle saw is equipped with the five circle saw blades (diameter 90 cm). The distance of the blades is adjustable. The splitter is equipped with a horizontal position blade (width 35 cm). The dimensions of the peat pieces are changeable, but from the point of drying the upper limit of the side of the peat cube can be 15-20 cm. The frost peat production method is technically suitable for production of slightly decomposed (H1-5) energy and horticultural peat. The energy peat pieces are allowed to dry up 70-75 % moisture content on the cutting field and then the pieces can be ridged by the screening ridger. If necessary, the ridges can be turned over. In the frost peat production, the conventional sod peat winning machines can be used in the following stages of the working tasks: harrowing, ridging, loading, turning of ridges and stockpiling. The measured output of the circle saw was about 45-50 m{sup 3}/h of energy peat and 58-63 m{sup 3}/h of horticultural peat. The output of the splitter was 120-150 m{sup 3}/h. Theoretically, the output of circle saw and the splitter can easily be doubled. Thereafter the production costs will be about 19 FIM/MWh of energy peat and 18,6 FIM/m{sup 3} of horticultural peat

  15. Growth of micropropagated lowbush blueberry with defined fungi in irradiated peat mix

    International Nuclear Information System (INIS)

    Litten, Walter; Smagula, J.M.; Dalpe, Yolande

    1992-01-01

    There is an interest in vegetative multiplication of high-yielding clones of Vaccinium angustifolium Ait. to establish or enhance blueberry production. This study evaluates mycorrhizal inoculation as an aid in such propagation from microcuttings. Shoots of Vaccinium angustifolium (clone 7062) generated in vitro were rooted in a peat-vermiculite-perlite substrate with or without ericoid mycorrhizal fungi fortification by Hymenoscyphus ericae or Scytalidium vaccinii and with or without peat sterilization by γ irradiation. Both in irradiated peat mix inoculated with S. vaccinii and in unirradiated peat mix with H. ericae, microcuttings grew taller and branched more than with the four other treatments. The profusely rooted plantlets available from all treatments of the cuttings put on significantly more total length of stems and branches after 167 days in the greenhouse when growing with either inoculant in unirradiated peat than in the unirradiated peat without inoculation. However, the magnitude of difference might be of borderline importance in commercial nursery operations. A higher level of copper and zinc in stem tissue was observed in stem tissue of plants grown with H. ericae with or without irradiation but not with S. vaccinii

  16. (D,T) Driven thorium hybrid blankets

    International Nuclear Information System (INIS)

    Al-Kusayer, T.A.; Khan, S.; Sahin, S.

    1983-01-01

    Recently, a project has started, with the aim to establish the neutronic performance and the basic design of an experimental fusionfission (hybrid) reactor facility, called AYMAN, in cylinderical geometry. The fusion reactor will have to be simulated by a (D,T) neutron generator. Fissile and fertile fuel will have to surround the neutron generator as a cylinderical blanket to simulate the boundary conditions of the hybrid blanket in a proper way. This geometry is consistent with Tandem Mirror Hybrid Blanket design and with most of the ICF blanket designs. A similar experimental installation will become operational around 1984 at the Swiss Federal Institute of Technology in Lausanne, Switzerland known under the project LOTUS. Due to the limited dimensions of the experimental cavity of the LOTUS-hybrid reactor, the LOTUS blankets have to be designed in plane geometry. Also, the bulky form of the Haefely neutron generator of the LOTUS facility obliges one to design a blanket in the plane geometry. This results in a vacuum left boundary conditions for the LOTUS blanket. The importance of a reflecting left boundary condition on the overall neutronic performance of a hybrid blanket has been analyzed in previous work in detail

  17. Safety indicators for the peat industry

    Energy Technology Data Exchange (ETDEWEB)

    Berezhnoy, S A; Sedov, Yu I; Yenoshevskiy, B A

    1981-01-01

    Members of the inter-institutional department of 'Labor Protection' of the KPI, in cooperation with members of the peat industry, have developed safety indicators for the peat industry in accordance with the requirements of GOST 12.4.026-76 SSBT, and established the range and order for their use. The safety indicators for the peat industry are divided into four groups (prohibiting, warning, regulating, and indicating), depending on the function.

  18. Effects of carbon dioxide on pyrolysis of peat

    International Nuclear Information System (INIS)

    Lee, Jechan; Yang, Xiao; Song, Hocheol; Ok, Yong Sik; Kwon, Eilhann E.

    2017-01-01

    This study focuses on the mechanistic understanding of effects of CO 2 on pyrolysis of peat. To do this, three pyrolytic products (i.e., syngas: H 2 and CO, pyrolytic oil (tar), and biochar) were characterized. Thermal cracking of volatile organic carbons (VOCs) generated from pyrolysis of peat was enhanced in the presence of CO 2 . Besides the enhanced thermal cracking of VOCs, unknown reaction between CO 2 and VOCs was also identified. Accordingly, CO 2 played a role in enhancing syngas production and in reducing tar formation in pyrolysis of peat. This study also reveals that peat-biochar produced in CO 2 exhibited a larger surface area than that produced in N 2 . The results shown in this paper would be used for various applications such as energy recovery from peat using a potent greenhouse gas (for example, CO 2 ). - Highlights: • More CO can be produced from pyrolysis of peat in CO 2 than in N 2 . • Less amount of tar produced from pyrolysis of peat in CO 2 than in N 2 . • Surface area of peat-biochar made in CO 2 is larger than that made in N 2 . • CO 2 can modify the quantity/quality of pyrolytic products from peat.

  19. Concepts for fusion fuel production blankets

    International Nuclear Information System (INIS)

    Gierszewski, P.

    1986-06-01

    The fusion blanket surrounds the burning hydrogen core of the fusion reactor. It is in this blanket that most of the energy released by the DT fusion reaction is converted into useable product, and where tritium fuel is produced to enable further operation of the reactor. Blankets will involve new materials, conditions and processes. Several recent fusion blanket concepts are presented to illustrate the range of ideas

  20. A blanket design, apparatus, and fabrication techniques for the mass production of multilayer insulation blankets for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Gonczy, J.D.; Boroski, W.N.; Niemann, R.C.; Otavka, J.G.; Ruschman, M.K.; Schoo, C.J.

    1989-09-01

    The multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) consists of full cryostat length assemblies of aluminized polyester film fabricated in the form of blankets and installed as blankets to the 4.5K cold mass and the 20K and 80K thermal radiation shields. Approximately 40,000 MLI blankets will be required in the 10,000 cryogenic devices comprising the SSC accelerator. Each blanket is nearly 17 meters long and 1.8 meters wide. This paper reports the blanket design, an apparatus, and the fabrication method used to mass produce pre-fabricated MLI blankets. Incorporated in the blanket design are techniques which automate quality control during installation of the MLI blankets in the SSC cryostat. The apparatus and blanket fabrication method insure consistency in the mass produced blankets by providing positive control of the dimensional parameters which contribute to the thermal performance of the MLI blanket. By virtue of the fabrication process, the MLI blankets have inherent features of dimensional stability three-dimensional uniformity, controlled layer density, layer-to-layer registration, interlayer cleanliness, and interlayer material to accommodate thermal contraction differences. 11 refs., 6 figs., 1 tab

  1. Peat - a slowly renewable biofuel

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The international investigation group of the Finnish Ministry of Trade and Industry suggest that peat should be classified as a slowly renewable energy source. Regeneration of peat can take up to thousands of years. Hence peat differs from wood energy, classified as renewable energy, and on the other hand from fossil fuels, such as coal. The report of the investigation group includes all the present research information on greenhouse gas balances of Finnish peatlands, i.e. how much greenhouse gases are liberated from Finnish mires, and on the other hand how much greenhouse gases they absorb. The net emissions of greenhouse gases of Finnish mires are over 10 million tons per year, and those of combustion of peat, mainly CO 2 , are over 8 million tons. The total greenhouse gas emissions of peat combustion and Finnish mire are estimated to be 19 (+- 9) % per year. This corresponds to about 25% of the total greenhouse gas emissions in Finland. The objective of the report was also to study the effects of the utilization of cutaway peat production areas (reforestation, returning the areas back to mires, agricultural utilization) on the greenhouse gas emission balances. The precise investigation of the effects of the greenhouse gas balances and the utilization of cutaway areas require further investigation and measurements at Finnish mires. The group consisted of Patrick Crill (USA), Ken Hargraves (GB) and Atte Korhola (FIN). The report of the group will be published in the Studies and Reports Serie of the Finnish Ministry of Trade and Industry both in English and in Finnish

  2. Breeding blanket for Demo

    International Nuclear Information System (INIS)

    Proust, E.; Giancarli, L.

    1992-01-01

    This paper presents the main design features, their rationale, and the main critical issues for the development, of the four DEMO-relevant blanket concepts presently investigated within the framework of the European Test-Blanket Development Programme

  3. Peat in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Ambak, K. [MARDI - Integrated Peat Research Station, Johor (Malaysia); Ah Chye, L. [MARDI Jalan Kebun, Selangor (Malaysia). Vegetable Research Centre

    1996-12-31

    Malaysian peatlands occur mostly in the water-saturated basins of the coastal lowlands. They are approximately 25 000 km{sup 2} in extent, of which about 10 000 km{sup 2} are in Peninsular Malaysia and another 15 000 km{sup 2} are distributed in Sarawak and Sabah. In Peninsular Malaysia, peatland classification is based mainly on peat depth and loss on ignition. In Sarawak, a more comprehensive approach is adopted, based on peat depth and the type of underlying mineral materials. As for Sabah, the classification follows FAD/UNESCO guidelines. Malaysian peatland is utilised mainly for agriculture. At present, about 32 % of the peatland area in Peninsular Malaysia is used for this purpose. In Sarawak, a much smaller percentage is used for agriculture. The main crops grown are oil-palm, rubber, coconut, padi and pineapple. Based on {sup 14}C datings, it has been estimated that peat in this region began to form between 4 000 and 5 000 years ago. The overall rate of accumulation of the peat since its initial formation has been about 2.81 mm ye` whereas the average rate during the early stages of formation ( 12-10 m) was 4.76 mm ye. In the intermediate stage (10-5 m), the average annual accumulation rate decreased to 3.14 mm, and to 2.22 mm in the final phase (5 m to the surface). (orig.) (17 refs.)

  4. Effect of Different Peat Size and Pre-Consolidation Pressure of Reconstituted Peat on Effective Undrained Shear Strength Properties

    Science.gov (United States)

    Azhar, ATS; Norhaliza, W.; Ismail, B.; Ezree, AM; Nizam, ZM

    2017-08-01

    Shear strength of the soil is one of the most important parameters in engineering design, especially during the pre- or post-construction periods, since it is mainly used to measure and evaluate the foundation or slope stability of soil. Peat normally known as a soil that has a very low value of shear strength, and in order to determine and understand the shear strength of the peat, it is a difficult task in geotechnical engineering due to several factors such as types of fabrics, the origin of the soil, water content, organic matter and the degree of humification. The aim of this study is to determine the effective undrained shear strength properties of reconstituted peat of different sizes. All the reconstituted peat samples were formed with the size that passed the opening sieve of 0.425 mm (effective undrained shear strength properties for reconstituted peat effective shear strength properties for the reconstituted peat effective undrained shear strength properties result obtained from the tests show that the reconstituted peat pore pressure, Δu, show both of peat

  5. Life cycle assessment of peat utilisation in Finland

    International Nuclear Information System (INIS)

    Maelkki, H.

    1997-01-01

    Environmental issues related to the production of peat and its use in energy generation have been the subject of public debate and research over the past few years in Finland. Peat is both an indigenous and a locally utilised fuel. Finland has no fossil fuel resources, and the transportation distances of imported fuels into Finland are normally long. In Finland the large peat resources can be utilised locally and peat-burning power plants are situated near the peatlands. Peat production and energy conversion methods are being continuously developed to make use of the environmentally and technically best available technology. In Finland peat formation exceeds peat utilisation and an increase in peat utilisation is therefore sustainable. The life cycle assessment concept gives an opportunity to evaluate and improve the environmental quality of peat utilisation options. The study focuses on an inventory analysis, but some of the most common methods of impact assessment with valuation are also included. The study also includes a comparison of fossil fuels and a discussion part. All the calculated results are based on net emissions. The background emissions of natural peatland are subtracted from the emissions of the utilisation phases. Milled peat and sod peat are reported in this study. Horticultural peat is studied simultaneously, but it will be reported later. The Sod Wave, Haku and Tehoturve methods are studied for the production of peat. The power plants of the study are Kempele heating plant and Rauhalahti cogeneration plant. The functional unit is 1 MWh produced total energy. The temporal boundaries vary from 112 to 128 years, depending on the peat production methods used. The restoration time is 100 years in all options. The emissions of greenhouse gases are based on the reports of The Finnish Research Programme on Climate Change. The water emissions are based on control monitoring reports from 1994 and 1995. The water emissions of the restoration phase are

  6. Effects of buffer thickness on ATW blanket performance

    International Nuclear Information System (INIS)

    Yang, W. S.; Mercatali, L.; Taiwo, T. A.; Hill, R. N.

    2001-01-01

    This paper presents preliminary results of target and buffer design studies for liquid metal cooled accelerator transmutation of waste (ATW) systems, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using 840 MWt liquid metal cooled ATW designs, the effects of buffer thickness on the blanket performance have been studied. Varying the buffer thickness for a given blanket configuration, system performance parameters have been estimated by a series of calculations using the MCNPX and REBUS-3 codes. The effects of source importance variation are studied by investigating the low-energy ( and lt; 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. For investigating irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. Results for the liquid-metal-cooled designs show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable. Investigation of the impact of the proton beam energy on the target and buffer design shows that for a given blanket power level, a lower beam energy (0.6 GeV versus 1 GeV) results in a higher irradiation damage to the beam window. This trend occurs because of the increase in the beam intensity required to maintain the power level

  7. Effects of Buffer Thickness on ATW Blanket Performance

    International Nuclear Information System (INIS)

    Yang, W.S.; Mercatali, L.; Taiwo, T.A.; Hill, R.N.

    2002-01-01

    This paper presents preliminary results of target and buffer design studies for liquid metal cooled accelerator transmutation of waste (ATW) systems, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using 840 MWt liquid metal cooled ATW designs, the effects of buffer thickness on the blanket performance have been studied. Varying the buffer thickness for a given blanket configuration, system performance parameters have been estimated by a series of calculations using the MCNPX and REBUS-3 codes. The effects of source importance variation are studied by investigating the low-energy (< 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. For investigating irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. Results for the liquid-metal-cooled designs show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable. Investigation of the impact of the proton beam energy on the target and buffer design shows that for a given blanket power level, a lower beam energy (0.6 GeV versus 1 GeV) results in a higher irradiation damage to the beam window. This trend occurs because of the increase in the beam intensity required to maintain the power level. (authors)

  8. Blankets for thermonuclear device

    International Nuclear Information System (INIS)

    Maki, Koichi; Fukumoto, Hideshi.

    1986-01-01

    Purpose: To produce tritium more than consumed, through thermonuclear reaction. Constitution: The energy spectrum of neutron generated by neutron multiplying reaction in a neutron multiplying blanket and moderated neutrons has a large ratio in a low energy section. In the low-energy absorption region of stainless steel which is a material of cooling pipes constituting a neutron multiplying blanket cooling channel, the neutrons are absorbed, lessening the neutron multiplying effect. To prevent this, the neutron multiplying blanket cooling channel is covered with tritium breeding blankets, thereby enabling the production of a substantially great amount of tritium more than the amount of tritium to be consumed by the thermonuclear reaction by preventing neutron absorption by the component materials of the cooling channel, improving the tritium breeding ratio by 20 to 25 %, and increasing the efficiency of use of neutrons for tritium generation. (Horiuchi, T.)

  9. Minimum thickness blanket-shield for fusion reactors

    International Nuclear Information System (INIS)

    Karni, Y.; Greenspan, E.

    1989-01-01

    A lower bound on the minimum thickness fusion reactor blankets can be designed to have, if they are to breed 1.267 tritons per fusion neutron, is identified by performing a systematic nucleonic optimization of over a dozen different blanket concepts which use either Be, Li 17 Pb 83 , W or Zr for neutron multiplication. It is found that Be offers minimum thickness blankets; that the blanket and shield (B/S) thickness of Li 17 Pb 83 based blankets which are supplemented by Li 2 O and/or TiH 2 are comparable to the thickness of Be based B/S; that of the Be based blankets, the aqueous self-cooled one offers one of the most compact B/S; and that a number of blanket concepts might enable the design of B/S which is approximately 12 cm and 39 cm thinner than the B/S thickness of, respectively, conventional self-cooled Li 17 Pb 83 and Li blankets. Aqueous self-cooled tungsten blankets could be useful for experimental fusion devices provided they are designed to be heterogeneous. (orig.)

  10. Peat origin and land use effects on microbial activity, respiration dynamics and exo-enzyme activities in drained peat soils in the Netherlands

    NARCIS (Netherlands)

    Brouns, Karlijn; Keuskamp, Joost; Potkamp, Gerrit; Verhoeven, J.T.A.; Hefting, Mariet M.

    2016-01-01

    This study assessed the risk of decomposition-driven soil subsidence in drained peat soils in the Netherlands, contrasting in peat origin and current land use. In a full factorial design, fen peat and bog peat were sampled from sites in use for nature conservation and for dairy farming, which

  11. Disruption problematics in segmented blanket concepts

    International Nuclear Information System (INIS)

    Crutzen, Y.; Fantechi, S.; Farfaletti-Casali, F.

    1994-01-01

    In Tokamaks, the hostile operating environment originated by plasma disruption events requires that the first wall/blanket/shield components sustain the large induced electromagnetic (EM) forces without significant structural deformation and within allowable material stresses. As a consequence there is a need to improve the safety features of the blanket design concepts satisfying the disruption problematics and to formulate guidelines on the required internal reinforcements of the blanket components. The present paper describes the recent investigations on blanket reinforcement systems needed in order to optimize the first-wall/blanket/shield structural design for next step and commercial fusion reactors in the context of ITER, DEMO and SEAFP activities

  12. Neutronics design aspects of reference ARIES-I fusion blanket

    International Nuclear Information System (INIS)

    Cheng, E.T.

    1990-12-01

    A SiC composite blanket concept was recently conceived for a deuterium-tritium burning, 1000 MW(e) tokamak fusion reactor design, ARIES-I. SiC composite structural material was chosen due to its very low activation features. High blanket nuclear performance and thermal efficiency, adequate tritium breeding, and a low level of activation are important design requirements for the ARIES-I reactor. The major approaches, other than using SiC as structural material, in meeting these design requirements, are to employ beryllium, the only low activation neutron multiplying material, and isotopically tailored Li 2 ZrO 3 , a tritium breeding material stable at high temperature, as blanket materials. 5 refs., 4 figs., 2 tabs

  13. Impact of managed moorland burning on peat nutrient and base cation status

    Science.gov (United States)

    Palmer, Sheila; Gilpin, Martin; Wearing, Catherine; Johnston, Kerrylyn; Holden, Joseph; Brown, Lee

    2013-04-01

    Controlled 'patch' burning of moorland vegetation has been used for decades in the UK to stimulate growth of heather (Calluna vulgaris) for game bird habitat and livestock grazing. Typically small patches (300-900 m2) are burned in rotations of 8-25 years. However, our understanding of the short-to-medium term environmental impacts of the practice on these sensitive upland areas has so far been limited by a lack of scientific data. In particular the effect of burning on concentrations of base cations and acid-base status of these highly organic soils has implications both for ecosystem nutrient status and for buffering of acidic waters. As part of the EMBER project peat chemistry data were collected in ten upland blanket peat catchments in the UK. Five catchments were subject to a history of prescribed rotational patch burning. The other five catchments acted as controls which were not subject to burning, nor confounded by other detrimental activities such as drainage or forestry. Soil solution chemistry was also monitored at two intensively studied sites (one regularly burned and one control). Fifty-centimetre soil cores, sectioned into 5-cm intervals, were collected from triplicate patches of four burn ages at each burned site, and from twelve locations at similar hillslope positions at each control site. At the two intensively monitored sites, soil solution chemistry was monitored at four depths in each patch. Across all sites, burned plots had significantly smaller cation exchange capacities, lower concentrations of exchangeable base cations and increased concentrations of exchangeable H+ and Al3+ in near-surface soil. C/N ratios were also lower in burned compared to unburned surface soils. There was no consistent trend between burn age and peat chemistry across all burned sites, possibly reflecting local controls on post-burn recovery rates or external influences on burn management decisions. At the intensively monitored site, plots burned less than two years

  14. Burning peat in Ireland: An electricity market dispatch perspective

    International Nuclear Information System (INIS)

    Tuohy, Aidan; Bazilian, Morgan; Doherty, Ronan; Gallachoir, Brian O; O'Malley, Mark

    2009-01-01

    This paper examines peat power production in Ireland under the three pillars of energy policy-security, competitiveness and environment. Peat contributes to energy security-as an indigenous fuel, it reduces dependency on imports. During a period of low capacity margins, the operation of the peat plants is useful from a system security perspective. Peat generation is being financially supported by consumers through an electricity levy. The fuel also has high carbon intensity. It is not politically viable to consider peat on equal economic criteria to other plant types because of history and location. This paper reviews electricity generation through combustion of peat in Ireland, and quantifies the costs of supporting peat utilising economic dispatch tools, finding the subsidy is not insignificant from a cost or carbon perspective. It shows that while peat is beneficial for one pillar of energy policy (security), the current usage of peat is not optimal from a competitiveness or environmental perspective. By switching from the current 'must-run' mode of operation for peat to the 'dispatched' mode used for the other generation, significant societal savings (in the range Euro 21 m per annum) can be achieved, as well as reducing system emissions by approximately 5% per year.

  15. Groundwater and quaternary geological studies of potential peat production areas - useful tool for sustainable peat production

    Energy Technology Data Exchange (ETDEWEB)

    Valpola, S.E.; Paalijaervi, M. (Geological Survey of Finland, Kokkola (Finland)), Email: samu.valpola@gtk.fi, Email: miikka.paalijarvi@gtk.fi

    2009-07-01

    Potential peat production areas in Finland are often situated in vicinity of eskers or other quaternary (glaciofluvial) formations. Frequently these formations are also important groundwater resources and it is essential for sustainable peat production to assure that these resources will not be endangered. The Geological Survey of Finland (GTK) has concluded several quaternary geological studies on potential peat production areas, which are connected to locally important groundwater areas. These studies have been made using mainly ground penetrating radar (GPR) and light drilling equipment. The main objective of these studies has been to establish the local groundwater flow directions and the quality and extent of quaternary deposits. The increasing need of peat production areas has created an evident demand of cost-effective and fast research methods which can be used for providing reliable information for planning of new production areas. (orig.)

  16. Development of Tropical Lowland Peat Forest Phasic Community Zonations in the Kota Samarahan-Asajaya area, West Sarawak, Malaysia

    Directory of Open Access Journals (Sweden)

    Mohamad Tarmizi Mohamad

    2016-01-01

    Full Text Available Logging observations of auger profiles (Tarmizi, 2014 indicate a vertical, downwards, general decrease of peat humification levels with depth in a tropical lowland peat forest in the Kota Samarahan-Asajaya area in the region of West Sarawak (Malaysia. Based on pollen analyses and field observations, the studied peat profiles can be interpreted as part of a progradation deltaic succession. Continued regression of sea levels, gave rise to the development of peat in a transitional mangrove to floodplain/floodbasin environment, followed by a shallow, topogenic peat depositional environment with riparian influence at approximately 2420 ± 30 years B.P. (until present time. The inferred peat vegetational succession reached Phasic Community I at approximately 2380 ± 30 years B.P. and followed by Phasic Community II at approximately 1780 ± 30 years B.P., towards the upper part of the present, ombrogenic, peat profile. Observations of the presence of large, hollow, Shorea type trees, supports that successive vegetational zonation of the tropical lowland peat dome may have reached Phasic Community II. Some pollen types were found that are also known to occur in the inferred vegetational zonation of Phasic Community III and IV or higher. Pollen analyses indicate that estuarine and deltaic, brackish to saline water influence may have gradually ceased at approximately 0.5 m below the lithological boundary between peat and underlying soil (floodplain deposit in the tropical lowland peat basin.

  17. Waste water from dewatering of peat

    International Nuclear Information System (INIS)

    Ringqvist, L.; Bergner, K.; Olsson, Tommy; Bystroem, P.

    1991-01-01

    The influence of waste water from mechanical dewatering of peat was tested on two species of stream invertebrates. We compared the effects of waste water from peat without any chemical treatment, and waste water from peat where one of the following treatments of the peat had preceded dewatering; a: acidification combined with addition of the cationic polymer Zetag 78 FS40, b: addition of aluminium in combination with the anionic polymer Magnafloc E10, c: polymerisation of the peat by acidification and addition of ferrous chloride and hydrogen peroxide. Waste water from Al/Magnafloc and from the polymerisation treatments had a higher content of suspended matter and a higher oxygen demand than those of other treatments. Total metal content of the water from all treatments was higher than in water from non-treated peat. Survival and growth of nymphs of the mayfly Heptagenia fuscogrisa and the stonefly Nemoura cinerea were compared in waste water from the different treatments. In all tests, the waste water was diluted to 5% (volume) with unchlorinated tapwater and pH was between 7.0-8.0 in all treatments during the experiment. The nymphs were fed with birch leaves that had been incubated in natural stream water for one month. Under these conditions, we did not find any significant effect of waste water on either survival or growth of these two species

  18. Peat filtration, field ditches and sedimentation basins for the purification of runoff water from peat mining areas

    International Nuclear Information System (INIS)

    Ihme, R.; Heikkinen, K.; Lakso, E.

    1991-01-01

    The aim of this research is to develop new methods and to improve those already in use to reduce the loading of watercourses from peat excavation areas. Factors examined were the use of peat filtration for the purification of the runoff water, load retention by the means of field ditches and improvement of the practicability and dredging of the settling ponds. Field research was carried out in peat production areas in the province of Oulu in 1987-1989

  19. Seasonal methane dynamics in three temperate grasslands on peat

    DEFF Research Database (Denmark)

    Schäfer, Carolyn; Elsgaard, Lars; Hoffmann, Carl Christian

    2012-01-01

    Background and Aims Drained peatlands are considered to be insignificant CH4 sources, but the effect of drainage on CH4 dynamics has not been extensively studied. We investigated seasonal dynamics of CH4 in two fen peat soils and one bog peat soil under permanent grassland in Denmark. Methods Soil......, even though soil CH4 concentrations of up to 155 and 1000 μmol CH4 dm−3 were measured in one of the fen peats and in the bog peat, respectively. Significant CH4 concentrations were observed above the water table. Methane production assays confirmed the presence of viable methanogens in the upper parts...... of the bog peat soil. The aerenchymous plant Juncus effusus L. liberated CH4 from the peat at rates of up to 3.3 mg CH4 m−2 h−1. No CH4 dynamics were observed in the second fen peat which, in contrast to the other two sites, had high sulfate concentrations. Conclusions Peat type and the distribution...

  20. Peat classified as slowly renewable biomass fuel

    International Nuclear Information System (INIS)

    2001-01-01

    The expert group, appointed by the Finnish Ministry of Trade and Industry, consisting of Dr. Patrick Crill from USA, Dr. Ken Hargreaves from UK and college lecturer Atte Korhola from Finland, studied the role of peat in Finnish greenhouse gas emissions. The group did not produce new research information, the report of the group based on the present research data available in Finland on greenhouse gas balances of Finnish mires and peat utilization, how much greenhouse gases, e.g. methane, CO 2 and N 2 O are liberated and bound by the mires. All the virgin peatlands in Finland (4.0 million ha), forest drained peatlands (5.7 million ha), peatlands used as fields in agriculture (0.25 million ha), peat harvesting and storage, as well as the actual peat production areas (0.063 million ha) are reviewed. The main factor intensifying the greenhouse effect, so called radiate forcing, is estimated to be the methane emissions from virgin peatlands, 11 million CO 2 equivalent tons per year. The next largest sources of emissions are estimated to be the CO 2 emissions of peat (8 million t/a), CO 2 emissions from peatlands in agricultural use (3.2 - 7.8 million t/a), the N 2 O emissions (over 2 million t/a) and methane emissions (less than 2 million t/a) of forest ditched peatlands. Other emission sources such as actual peat production and transportation are minimal. Largest carbon sinks are clearly forest-drained peatlands (9.4 - 14.9 million t/a) and virgin peatlands (more than 3 million t/a). Main conclusions of the experts group is that peat is formed continuously via photosynthesis of mosses, sedges and under-shrub vegetation and via forest litter formation. The report discovers that the basics of the formation of peat biomass is similar to that of other plant-based biomasses, such as wood, but the time required by stratification is different. Forests in Southern Finland become ready for harvesting in about 100 years, but the formation of commercially viable peat layers takes

  1. Excavation-drier method of energy-peat extraction reduces long-term climatic impact

    Energy Technology Data Exchange (ETDEWEB)

    Silvan, N.; Silvan, K.; Laine, J. [Finnish Forest Research Inst., Parkano (Finland)], e-mail: niko.silvan@metla.fi; Vaisanen, S.; Soukka, R. [Lappeenranta Univ.of Techology (Finland)

    2012-11-01

    Climatic impacts of energy-peat extraction are of increasing concern due to EU emissions trading requirements. A new excavation-drier peat extraction method has been developed to reduce the climatic impact and increase the efficiency of peat extraction. To quantify and compare the soil GHG fluxes of the excavation drier and the traditional milling methods, as well as the areas from which the energy peat is planned to be extracted in the future (extraction reserve area types), soil CO{sub 2}, CH{sub 4} and N{sub 2}O fluxes were measured during 2006-2007 at three sites in Finland. Within each site, fluxes were measured from drained extraction reserve areas, extraction fields and stockpiles of both methods and additionally from the biomass driers of the excavation-drier method. The Life Cycle Assessment (LCA), described at a principal level in ISO Standards 14040:2006 and 14044:2006, was used to assess the long-term (100 years) climatic impact from peatland utilisation with respect to land use and energy production chains where utilisation of coal was replaced with peat. Coal was used as a reference since in many cases peat and coal can replace each other in same power plants. According to this study, the peat extraction method used was of lesser significance than the extraction reserve area type in regards to the climatic impact. However, the excavation-drier method seems to cause a slightly reduced climatic impact as compared with the prevailing milling method. (orig.)

  2. U.S. technical report for the ITER blanket/shield: A. blanket: Topical report, July 1990--November 1990

    International Nuclear Information System (INIS)

    1995-01-01

    Three solid-breeder water-cooled blanket concepts have been developed for ITER based on a multilayer configuration. The primary difference among the concepts is in the fabricated form of breeder and multiplier. All the concepts have beryllium for neutron multiplication and solid-breeder temperature control. The blanket design does not use helium gaps or insulator material to control the solid breeder temperature. Lithium oxide (Li 2 O) and lithium zirconate (Li 2 ZrO 3 ) are the primary and the backup breeder materials, respectively. The lithium-6 enrichment is 95%. The use of high lithium-6 enrichment reduces the solid breeder volume required in the blanket and consequently the total tritium inventory in the solid breeder material. Also, it increases the blanket capability to accommodate power variation. The multilayer blanket configuration can accommodate up to a factor of two change in the neutron wall loading without violating the different design guidelines. The blanket material forms are sintered products and packed bed of small pebbles. The first concept has a sintered product material (blocks) for both the beryllium multiplier and the solid breeder. The second concept, the common ITER blanket, uses a packed bed breeder and beryllium blocks. The last concept is similar to the first except for the first and the last beryllium zones. Two small layers of beryllium pebbles are located behind the first wall and the back of the last beryllium zone to reduce the total inventory of the beryllium material and to improve the blanket performance. The design philosophy adopted for the blanket is to produce the necessary tritium required for the ITER operation and to operate at power reactor conditions as much as possible. Also, the reliability and the safety aspects of the blanket are enhanced by using low-pressure water coolant and the separation of the tritium purge flow from the coolant system by several barriers

  3. Evaluation of ecological constraints on peat mining in New Brunswick

    Energy Technology Data Exchange (ETDEWEB)

    Gautreau-Daigle, H

    1990-07-01

    A study was undertaken to obtain baseline information on moose and waterfowl usage of peatlands in the Escuminac bog complex in New Brunswick, in order to determine the impact of existing peat mining activities and to assist in making decisions regarding future resource development. The bog complex comprises a relatively large number of freshwater ponds which support breeding populations for waterfowl and serve as staging areas during bird migrations. Aerial surveys were carried out to quantify the use of these ponds by waterfowl and to determine changes in their level of use as a result of peat extraction. Results indicate that usage of ponds by birds seems mostly limited to staging and migration, except for black and ring-necked ducks. Those species are the most significant users of bog ponds and have been found to breed and raise young in the ponds. Some areas were found to get more waterfowl than others, but this was not shown to be related to peat mining activity. Active mined areas were devoid of waterfowl, but this area was a relatively small portion of the total bog area. The moose survey examined moose activity in a control area (without peat mining) and a representative bog area where peat mining occurred. Results do not indicate a difference in the moose activity patterns between the two areas. 9 refs., 25 figs., 17 tabs.

  4. LMFBR blanket physics project progress report No. 4

    International Nuclear Information System (INIS)

    Driscoll, M.J.; Lanning, D.D.; Kaplan, I.; Supple, A.T.

    1973-01-01

    During the period covered by the report, July 1, 1972, through June 30, 1973, work was devoted to completion of experimental measurements and data analysis on Blanket Mockup No. 3, a graphite-reflected blanket, and to initiation of experimental work on Blanket Mockup No. 4, a steel-reflected assembly designed to mock up a demonstration plant blanket. Work was also carried out on the analysis of a number of advanced blanket concepts, including the use of high-albedo reflectors, the use of thorium in place of uranium in the blanket region, and the ''parfait'' or completely internal blanket concept. Finally, methods development work was initiated to develop the capability for making gamma heating measurements in the blanket mockups. (U.S.)

  5. The geology, botany and chemistry of selected peat-forming environments from temperate and tropical latitudes

    Science.gov (United States)

    Cameron, C.C.; Esterle, J.S.; Palmer, C.A.

    1989-01-01

    Peat has been studied in several geologic settings: (1) glaciated terrain in cold temperate Maine and Minnesota, U.S.A.; (2) an island in the Atlantic Ocean off the coast of Maine, where sea level is rising; (3) the warm temperate U.S. Atlantic and Gulf Coastal Plains, where sea level has changed often; and (4) the tropical coast of Sarawak, Malaysia, and the tropical delta of the Batang Hari River, Sumatra, Indonesia. Most of these deposits are domed (ombrotrophic or partly ombrotrophic) bogs in which peat accumulation continued above the surface of the surrounding soil. However, the bogs of the U.S. Atlantic and Gulf Coastal Plains are comparatively not as domed, and many have almost level surfaces. In some bogs, aquatic or semi-aquatic plant materials accumulated, replaced water in the depressions, and formed a surface on which marsh or swamp vegetation could subsequently live, die, and accumulate. In others, the plant materials accumulated initially on level silt or sand surfaces supporting marshes or swamps. As the peat dome formed, plants growing on it changed from luxuriant ones near the base of the dome, where nutrients were brought into the bog by surface and ground water, to stunted ones at the top of the dome, where the raised bogs are fed by nutrient-poor precipitation. The physical and chemical changes that take place in the sequence of environments from the pond stage of deposit development, through the grassy marsh stage, through the forested swamp stage, and finally through the heath dome stage can be measured in terms of acidity and ash, volatile matter, carbon, hydrogen, nitrogen, sulfur and oxygen contents, as well as in the kind and distribution of trace elements. The organic and inorganic contents of the deposits relate to geomorphology, and geomorphology relates to their settings. As models of coal formation, some domed peat deposits may help in solving problems of distribution and character of ancient coal beds. But clearly not all peat

  6. Self-cooled liquid-metal blanket concept

    International Nuclear Information System (INIS)

    Malang, S.; Arheidt, K.; Barleon, L.

    1988-01-01

    A blanket concept for the Next European Torus (NET) where 83Pb-17Li serves both as breeder material and as coolant is described. The concept is based on the use of novel flow channel inserts for a decisive reduction of the magnetohydrodynamic (MHD) pressure drop and employs beryllium as neutron multiplier in order to avoid the need for breeding blankets at the inboard side of the torus. This study includes the design, neutronics, thermal hydraulics, stresses, MHDs, corrosion, tritium recovery, and safety of a self-cooled liquid-metal blanket. The results of the investigations indicate that the self-cooled blanket is an attractive alternative to other driver blanket concepts for NET and that it can be extrapolated to the conditions of a DEMO reactor

  7. Sedimentology of Fraser River delta peat deposits: a modern analogue for some deltaic coals

    Energy Technology Data Exchange (ETDEWEB)

    Styan, W B; Bustin, R M

    1984-01-01

    On the Recent lobe of the Fraser River delta, peat accumulation has actively occurred on the distal lower delta plain, the transition between upper and lower delta plains, and the alluvial plain. Distal lower delta plain peats developed from widespread salt and brackish marshes and were not influenced appreciably by fluvial activity. Lateral development of the marsh facies were controlled by compaction and eustatic sea-level rise. The resulting thin, discontinuous peat network contains numerous silty clay partings and high concentrations of sulphur. Freshwater marsh facies formed but were later in part eroded and altered by transgressing marine waters. Peats overlie a thin, fluvial, fining-upward sequence which in turn overlies a thick, coarsening-upward, prodelta-delta front succession. Lower- upper delta plain peats initially developed from interdistributary brackish marshes and were later fluvially influenced as the delta prograded. Thickest peats occur in areas where distributary channels were abandoned earliest. Sphagnum biofacies replace sedge-grass-dominated communities except along active channel margins, where the sedge-grass facies is intercalated with overbank and splay deposits. Peats are underlain by a relatively thin sequence of fluvial deposits which in turn is underlain by a major coarsening-upward delta front and pro-delta sequence. Alluvial plain peats accumulated in back swamp environments of the flood plain. Earliest sedge-clay and gyttja peats developed over thin fining-upward fluvial cycles or are interlaminated with fine-grained flood deposits. Thickest accumulations occur where peat fills small avulsed flood channels. Overlying sedge-grass and sphagnum biofacies are horizontally stratified and commonly have sharp boundaries with fine-grained flood sediments. At active channel margins, however, sedge-grass peats are intercalated with natural levee deposits consisting of silty clay.

  8. Climate mitigation scenarios of drained peat soils

    Science.gov (United States)

    Kasimir Klemedtsson, Åsa; Coria, Jessica; He, Hongxing; Liu, Xiangping; Nordén, Anna

    2014-05-01

    The national inventory reports (NIR) submitted to the UNFCCC show Sweden - which as many other countries has wetlands where parts have been drained for agriculture and forestry purposes, - to annually emit 12 million tonnes carbon dioxide equivalents, which is more GHG'es than industrial energy use release in Sweden. Similar conditions can be found in other northern countries, having cool and wet conditions, naturally promoting peat accumulation, and where land use management over the last centuries have promoted draining activities. These drained peatland, though covering only 2% of the land area, have emissions corresponding to 20% of the total reported NIR emissions. This substantial emission contribution, however, is hidden within the Land Use Land Use Change and Forestry sector (LULUCF) where the forest Carbon uptake is even larger, which causes the peat soil emissions become invisible. The only drained soil emission accounted in the Swedish Kyoto reporting is the N2O emission from agricultural drained organic soils of the size 0.5 million tonnes CO2e yr-1. This lack of visibility has made incentives for land use change and management neither implemented nor suggested, however with large potential. Rewetting has the potential to decrease soil mineralization, why CO2 and N2O emissions are mitigated. However if the soil becomes very wet CH4 emission will increase together with hampered plant growth. By ecological modeling, using the CoupModel the climate change mitigation potential have been estimated for four different land use scenarios; 1, Drained peat soil with Spruce (business as usual scenario), 2, raised ground water level to 20 cm depth and Willow plantation, 3, raised ground water level to 10 cm depth and Reed Canary Grass, and 4, rewetting to an average water level in the soil surface with recolonizing wetland plants and mosses. We calculate the volume of biomass production per year, peat decomposition, N2O emission together with nitrate and DOC

  9. Distilling peat and other carbonaceous matters

    Energy Technology Data Exchange (ETDEWEB)

    Stones, W B

    1850-03-07

    Improvements in treating peat and other carbonaceous and ligneous matters, so as to obtain products therefrom are disclosed. These improvements consist, first, of a machine for compressing and partially drying peat. The unpressed peat is put into boxes and these into frames which are passed through between the bowls of a machine resembling a pair of squeezers. Secondly, consists in distilling, at a temperature of, say 700/sup 0/F, the compressed peat, with or without the addition of tar or fatty matter in retorts, and condensing the vapors in a series of vessels, arranged after the manner of Wolfe's bottles. The resulting charcoal may be extinguished by passing carbonic acid through it while in an air-tight box or chamber, and it may then be compressed into bricks, and used for locomotives and other purposes.

  10. Influence of the level of subsoil water on the distribution of moisture content in a peat formation

    Energy Technology Data Exchange (ETDEWEB)

    Fedotov, A.I.; Kostyuk, N.S.

    1983-01-01

    Under laboratory and field conditions, observations are made of the influence of the level of subsoil water on the distribution of moisture content in the upper layers of the peat formation. It is established that prolonged evaporation sharply reduces the moisture content of the upper layers of the formation at a depth up to 20cm. Precipitation is mainly absorbed by the upper layers of the formation and can penetrate in the season with level of subsoil water about 1m at depth of no more than 50cm. The zone of complete capillary water-saturation of the upper formation does not exceed 45cm.

  11. The genesis, stratigraphy and age of Finnish peat deposits. Soiden syntvy, rakenne ja ikae Suomessa

    Energy Technology Data Exchange (ETDEWEB)

    Glueckert, G [Turun yliopisto (Finland). Maaperaegeologian osasto

    1986-01-01

    The genesis, stratigraphy and age of Finnish peat deposits are briefly described. Finnish peats are classified according to their botanical composition to Sphagnum, sedge (Carex) and wood peats. They form complex types of peat land: the ombrotrophic raised bogs in southern Finland and the minerotrophic open sedge (aapa) bogs in northern Finland. The structural bog types in the geological classification are mainly composed of Sphagnum and Carex peats. The raised bogs are predominantly built up of Sphagnum peat, the aapa bogs of Carex peat. The bogs are formed by paludification of lakes, of rising coasts or of low-lying forests. The thickness of peat varies from 3 to 8 m in southern Finland and from 1 to 3 m in northern Finland. The age of the bogs varies according to the uplift of land and the altitude of the bog gasin above sea level. The oldest bogs are 9500-10000 years old and formed in southern and eastern Finland on high-lying upland tracts just after the retreat of the ice at the end of the last glaciation. The geological and palaeontological development of bogs and the history of climate and vegetation can be studied and dated pollenanalytically and with the radiocarbon method.

  12. Blanket comparison and selection study. Volume II

    International Nuclear Information System (INIS)

    1983-10-01

    This volume contains extensive data for the following chapters: (1) solid breeder tritium recovery, (2) solid breeder blanket designs, (3) alternate blanket concept screening, and (4) safety analysis. The following appendices are also included: (1) blanket design guidelines, (2) power conversion systems, (3) helium-cooled, vanadium alloy structure blanket design, (4) high wall loading study, and (5) molten salt safety studies

  13. Study of the production of compacted peat; Tiivistetyn turpeen tuotantotutkimus

    Energy Technology Data Exchange (ETDEWEB)

    Erkkilae, A [VTT Energy, Jyvaeskylae (Finland)

    1997-12-01

    The so-called Compeat method developed at VTT Energy is applied by field experiments to peat production. The aim of the two-year project (1996 - 1997) is to achieve an increase of 20 % in hectare yield with this new production method of compacted peat in pilot scale in field conditions without any increase in production costs. The aim of the 1996 study was to construct a prototype mining machine for compacted peat and to produce compacted peat from Carex and Sphagnum peat fields in test runs. The operation of the mining machine was studied and drying of compacted peat with that of milled peat were compared at peat production sites of Vapo Oy and Turveruukki Oy. The results of the drying studies were along the same lines with previous laboratory drying tests. The dry matter yield of Compeat was more than twice that of milled peat in the Carex peat field and 1.1-1.5-fold in the Sphagnum field. Compeat moistened significantly less in the rain than normally milled peat. Compeat was ridged with a scraper-ridger. The mining machine produced sufficiently compacted and well-drying peat, but its power demand was too high. The aim is to reduce the power consumption of the mining machine significantly to make it possible to use a wheel- tractor for pulling and to reduce the production costs of the method lower than those of the milled peat method. The drying results of Compeat were so promising that the development of the field machine will be continued. (orig.)

  14. Reduced ash-related operational problems by co-combustion peat and agricultural fuels; Minskade askrelaterade driftsproblem genom inblandning av torv i aakerbraenslen

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Marcus; Bostroem, Dan; Skoglund, Nils; Grimm, Alejandro; Boman, Christoffer; Kofod-Hansen, Marie

    2010-06-15

    The objectives of the project were: To determine the admixing levels for different peat classes to various energy crops (straw, Salix and Reed canary grass) that are required to reach positive effects regarding slagging, deposit formation/(high temperature corrosion) and bed agglomeration; and, To demonstrate the possibilities to reduce the occurrence of ash related operational problems in combustion of energy crops upon admixing peat. Operational experiences and research of effects of co-firing peat and energy crops are scarce. Some previous tests in bench scale indicated though, on a strong reduction of the agglomeration tendency and lowering of the agglomeration temperature for straw and Salix at a peat admixing level corresponding to 15 - 20 weight% (on DS basis). A reduction in the amount of emitted fine particles was also observed in these experiments. However, care must be taken in the choice of peat. Some Carex dominated peats with high Si contents may cause problems with slagging. Another conclusion from the mentioned bench scale tests was that peats with relative high Ca/Si ratios should be selected to minimize the risk of slagging and bed agglomeration. Thermochemical modelling was performed to determine the effects of peat admixture, on slagging-, deposit formation- (corrosion)- and bed agglomeration tendencies during combustion of straw, willow and reed canary grass with high and low ash content. These results and previously conducted bench scale experiments were used as a basis for determining combinations of fuel and peat admixtures for the demonstration experiments. The calculations were performed with admixing levels of 0-, 5-, 15, 25-, and 40 weight% (on DS basis) of four peat samples to the investigated four crop fuels. The used peat samples were typical carex-containing Swedish peat with differences in e.g. silicon-, calcium- and sulfur contents. A number of the model calculations were qualitatively validated against previously conducted

  15. Blanket materials for DT fusion reactors

    International Nuclear Information System (INIS)

    Smith, D.L.

    1981-01-01

    This paper presents an overview of the critical materials issues that must be considered in the development of a tritium breeding blanket for a tokamak fusion reactor that operates on the D-T-Li fuel cycle. The primary requirements of the blanket system are identified and the important criteria that must be considered in the development of blanket technology are summarized. The candidate materials are listed for the different blanket components, e.g., breeder, coolant, structure and neutron multiplier. Three blanket concepts that appear to offer the most potential are: (1) liquid-metal breeder/coolant, (2) liquid-metal breeder/separate coolant, and (3) solid breeder/separate coolant. The major uncertainties associated with each of the design concepts are discussed and the key materials R and D requirements for each concept are identified

  16. Development of an underdrained peat production field; Salaojitetun tuotantokentaen kehittaeminen

    Energy Technology Data Exchange (ETDEWEB)

    Hillebrand, K.

    1996-12-31

    The objective of the study is to examine the possibilities to improve the drainage of a peat production field using a numerical groundwater model. The effects of the ditch spacing and the drainage method on the groundwater level are studied. The way of ditching for basic drainage of virgin peatland, and the calculation of possible additional ditching in peat production fields, including the shallow areas, are considered. Also, the possibility of increasing the customary ditch spacing of 20 m is examined. The objective for drainage techniques is to cut the time for peatland preparation in half, and to increase the space between open field ditches from the present 20 meters to 60 - 80 meters by making use of underdrains. In this way it is possible to reduce the peat production costs about 5%. In 1995 the numerical groundwater model has been validated at Pajusuo drainage area. According to the comparison of the groundwater level calculated with the model and measured at Pajusuo, the agreement was very satisfactory. Uncertainty in the calculations derived mainly from the difficulties of assessing the pF curve and the hydraulic conductivity of the soil, as well as the water-carrying capacity of the mole drains. In general one can predict the groundwater level with an accuracy of +- 10 cm. Also the possibility to increase the hydraulic conductivity of peat by a chemical additive was studied. Adding 3 kg chemical per 1 kg dry matter it was possible to increase the hydraulic conductivity over twenty fold. In this way it is possible to construct vertical underdrains to improve the infiltration after rainfall

  17. Blanket maintenance by remote means using the cassette blanket approach

    International Nuclear Information System (INIS)

    Werner, R.W.

    1978-01-01

    Induced radioactivity in the blanket and other parts of a fusion reactor close to the plasma zone will dictate remote assembly, disassembly, and maintenance procedures. Time will be of the essence in these procedures. They must be practicable and certain. This paper discusses the reduction of a complicated Tokamak reactor to a simpler assembly via the use of a vacuum building in which to house the reactor and the introduction in this new model of cassette blanket modules. The cassettes significantly simplify remote handling

  18. Chemical properties of peat used in balneology

    Science.gov (United States)

    Szajdak, L.; Hładoń, T.

    2009-04-01

    The physiological activity of peats is observed in human peat-bath therapy and in the promotion of growth in some plants. Balneological peat as an ecologically clean and natural substance is perceived as being more 'human friendly' than synthetic compounds. Poland has a long tradition of using balneological peat for therapeutic purposes. Balneological peat reveals a physical effect by altering temperature and biochemical effects through biologically active substances. It is mainly used for the treatment of rheumatic diseases that are quite common in Poland. Peat represents natural product. Physico-chemical properties of peat in particular surface-active, sorption and ion exchanges, defining their biological function, depend mainly on the chemical composition and molecular structure of humic substances representing the major constituent of organic soil (peat). The carbon of organic matter of peats is composed of 10 to 20% carbohydrates, primarily of microbial origin; 20% nitrogen-containing constituents, such as amino acids and amino sugars; 10 to 20% aliphatic fatty acids, alkanes, etc.; with the rest of carbon being aromatic. For balneology peat should be highly decomposed (preferably H8), natural and clean. The content of humic acids should exceed 20% of dry weight, ash content will be less than 15 15% of dry weight, sulphur content less than 0.3% of dry weight and the amount of water more than 85%. It will not contain harmful bacteria and heavy metals. Humic substances (HS) of peat are known to be macromolecular polydisperse biphyllic systems including both hydrophobic domains (saturated hydrocarbon chains, aromatic structural units) and hydrophilic functional groups, i. e having amphiphilic character. Amphiphilic properties of FA are responsible for their solubility, viscosity, conformation, surfactant-like character and a variety of physicochemical properties of considerable biologically practical significance. The chemical composition of peats depends

  19. U.S. technical report for the ITER blanket/shield: A. blanket: Topical report, July 1990--November 1990

    Energy Technology Data Exchange (ETDEWEB)

    1995-01-01

    Three solid-breeder water-cooled blanket concepts have been developed for ITER based on a multilayer configuration. The primary difference among the concepts is in the fabricated form of breeder and multiplier. All the concepts have beryllium for neutron multiplication and solid-breeder temperature control. The blanket design does not use helium gaps or insulator material to control the solid breeder temperature. Lithium oxide (Li{sub 2}O) and lithium zirconate (Li{sub 2}ZrO{sub 3}) are the primary and the backup breeder materials, respectively. The lithium-6 enrichment is 95%. The use of high lithium-6 enrichment reduces the solid breeder volume required in the blanket and consequently the total tritium inventory in the solid breeder material. Also, it increases the blanket capability to accommodate power variation. The multilayer blanket configuration can accommodate up to a factor of two change in the neutron wall loading without violating the different design guidelines. The blanket material forms are sintered products and packed bed of small pebbles. The first concept has a sintered product material (blocks) for both the beryllium multiplier and the solid breeder. The second concept, the common ITER blanket, uses a packed bed breeder and beryllium blocks. The last concept is similar to the first except for the first and the last beryllium zones. Two small layers of beryllium pebbles are located behind the first wall and the back of the last beryllium zone to reduce the total inventory of the beryllium material and to improve the blanket performance. The design philosophy adopted for the blanket is to produce the necessary tritium required for the ITER operation and to operate at power reactor conditions as much as possible. Also, the reliability and the safety aspects of the blanket are enhanced by using low-pressure water coolant and the separation of the tritium purge flow from the coolant system by several barriers.

  20. Excavation and drying of compressed peat; Tiivistetyn turpeen nosto ja kuivaus

    Energy Technology Data Exchange (ETDEWEB)

    Erkkilae, A.; Frilander, P.; Hillebrand, K.; Nurmi, H.

    1996-12-31

    The target of this three year (1993 - 1995) project was to improve the peat product-ion efficiency by developing an energy economical excavation method for compressed peat, by which it is possible to obtain best possible degree of compression and load from the DS-production point of view. It is possible to improve the degree of utilization of solar radiation in drying from 30 % to 40 %. The main research areas were drying of the compressed peat and peat compression. The third sub-task for 1995 was demonstration of the main parts of the method in laboratory scale. Experimental compressed peat (Compeat) drying models were made for peats Carex-peat H7, Carex-peat H5 and Carex-Sphagnum-peat H7. Compeat dried without turning in best circumstances in 34 % shorter time than milled layer made of the same peat turned twice, the initial moisture content being 4 kgH2OkgDS-1. In the tests carried out in 1995 with Carex-peat the compression had not corresponding effect on intensifying of the drying of peat. Compression of Carex-Sphagnum peat H7 increased the drying speed by about 10 % compared with the drying time of uncompressed milled layer. In the sprinkling test about 30-50 % of the sprinkled water was sucked into the compressed peat layer, while about 70 % of the rain is sucked into the corresponding uncompressed milled layer. Use of vibration decreased the energy consumption of the steel-surfaced nozzles about 20 % in the maximum, but the effect depend on the rotation speed of the macerator and the vibration power. In the new Compeat method (production method for compressed peat), developed in the research, the peat is loosened from the field surface by milling 3-5 cm thick layer of peat of moisture content 75-80 %

  1. Measurements relevant to simulating subcriticality in ADS facilities with blanket

    International Nuclear Information System (INIS)

    Titarenko, Yu. E.; Batyaev, V.F.; Borovlev, S.P.; Gladkikh, N.G.; Igumnov, M.M.; Legostaev, V.O.; Karpikhin, E.I.; Konev, V.N.; Kushnerev, Yu.T.; Popkov, V.N.; Ryazhsky, V.I.; Spiridonov, V.G.; Chernyavsky, E.V.; Shvedov, O.V.

    2009-10-01

    The work presents the results of determining the blanket subcriticality for a zero-power heavy water reactor MAKET at the Institute for Theoretical and Experimental Physics, Moscow. The blanket is hexagonal lattice made of 36 90%-enriched 235U fuel rods spaced 173mm apart. The subcriticality was varied from ∼0.3% to 5% by adjusting the heavy water level. The subcriticality values were calibrated using the dependence of reactivity on heavy water level. The pulsed neutron source technique was used to measure the temporal dependence of neutron field at different blanket points for the calibrated subcriticality values. The subciticality values obtained in terms of the 'inverse clock' formulae using the decay constants of the measured dependences proved to differ from the calibrated subcriticalities by not more than 7% at the average. The MCNP code-aided simulations of the experiment made has given the calibrated keff values at prescribed heavy water levels and led to the neutron field decay constants at given points, which differ on the average from their experimental values by not more than 7% too. (author)

  2. Raising surface water levels in peat areas with dairy farming upscaling hydrological, agronomical and economic effects from farm-scale to local scale.

    NARCIS (Netherlands)

    Vos, de J.A.; Bakel, van P.J.T.; Hoving, I.E.; Smidt, R.A.

    2010-01-01

    Raising surface water levels in peat areas is a measure to reduce soil subsidence, to prevent decay of wooden foundations and to stimulate wet nature restoration and reduce greenhouse gas emissions. However, in these areas dairy farms are present and farming at wetter soils is difficult due to lower

  3. Order-of-magnitude increase of Hg in Norwegian peat profiles since the outset of industrial activity in Europe

    International Nuclear Information System (INIS)

    Steinnes, Eiliv; Sjobakk, Torill Eidhammer

    2005-01-01

    Peat cores from six ombrotrophic bogs at different latitudes in Norway (58 deg N-69 deg N) were analysed for Hg by atomic fluorescence spectrometry. In all cases a smooth decrease of Hg with depth was observed down to 15-20 cm. At greater depths Hg showed a relatively constant level of the order of 10% of that in the peat surface layer. In the surface peat Hg concentrations exhibit moderate variation with latitude. The pre-industrial levels of Hg in the peat correspond to a net annual Hg accumulation of 0.3-0.9 μg m -2 . The Hg accumulation over the last 100 years is about 15 times higher on average than the pre-industrial level. The present work supports the view that a major part of the present atmospheric Hg in the Northern Hemisphere is of anthropogenic origin. It is speculated that the comparatively high Hg contemporary accumulation rates observed at the Andoya bog on 69 deg N may be related to the Arctic springtime depletion of Hg. - Results from analyses of ombrotrophic peat cores support the view that the present level of Hg 0 in the atmosphere is mainly of anthropogenic origin

  4. Design requirement on HYPER blanket fuel assembly

    International Nuclear Information System (INIS)

    Hwang, Woan; Lee, B. O.; Nam, C.; Ryu, W. S.; Lee, B. S.; Park, W. S.

    2000-07-01

    This document describes design requirements which are needed for designing the blanket assembly of the HYPER as design guidance. The blanket assembly of the HYPER consists of blanket fuel rods, mounting rail, spacer, upper nozzle with handling socket, bottom nozzle with mounting rail and skeleton structure. The blanket fuel rod consists of top end plug, bottom end plug with key way, blanket fuel slug, and cladding. In the assembly, the rods are in a triangular pitch array. This report contains functional requirements, performance and operational requirements, interfacing systems requirements, core restraint and interface requirements, design limits and strength requirements, system configuration and essential feature requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements for the blanket fuel assembly of the HYPER

  5. Conceptual study on high performance blanket in a spherical tokamak fusion-driven transmuter

    International Nuclear Information System (INIS)

    Chen Yixue; Wu Yican

    2000-01-01

    A preliminary conceptual design on high performance dual-cooled blanket of fusion-driven transmuter is presented based on neutronic calculation. The dual-cooled system has some attractive advantages when utilized in transmutation of HLW (High Level Wastes). The calculation results show that this kind of blanket could safely transmute about 6 ton minor actinides (produced by 170 GW(e) Year PWRs approximately) and 0.4 ton fission products per year, and output 12 GW thermal power. In addition, the variation of power and critical factor of this blanket is relatively little during its 1-year operation period. This blanket is also tritium self-sustainable

  6. Fusion-reactor blanket and coolant material compatibility

    International Nuclear Information System (INIS)

    Jeppson, D.W.; Keough, R.F.

    1981-01-01

    Fusion reactor blanket and coolant compatibility tests are being conducted to aid in the selection and design of safe blanket and coolant systems for future fusion reactors. Results of scoping compatibility tests to date are reported for blanket material and water interactions at near operating temperatures. These tests indicate the quantitative hydrogen release, the maximum temperature and pressures produced and the rates of interactions for selected blanket materials

  7. Coal-peat compositions for co-combustion in local boilers

    Directory of Open Access Journals (Sweden)

    А. В. Михайлов

    2016-08-01

    Full Text Available In article results of experiments on creation of coal and peat fuel compositions for burning in solid-fuel boilers are described. The main objective of research consisted in development of combination of coal dust and natural peat without binding additives. The role of peat consists that it increases efficiency of process of granulation, being natural binding. The method of granulation allows to utilize waste of the coal industry. Joint burning of two types of fuel – coal dust and peat reduces emission of sulfur dioxides. The cost of peat raw materials is lower, than artificial binding, applied to briquetting of coal dust. The composition of mix of coal dust and peat varied in the ratio 2:1, 1:1 and 1:2 in volume ratio at humidity of mix before extrusion of 65 %. In the course of preparatory operations of coal raw materials its crushing and sifting through sieve of 24 mesh (0,707 mm was carried out. Procedure of hashing of samples of coal and peat was carried out before receiving homogeneous mixture. After hashing mix was located in piston press for receiving granules. Coal dust and wet peat pass semifixed extrusion on piston press with formation of cylindrical granules with a diameter of 16 mm. After extrusion of granule are dried to operational humidity of 25 %. Coal and peat fuel granules showed sufficient mechanical strength for transportation and power feed in solid-fuel boilers. Burning of coal and peat fuel granules in vitro at temperature of 800 °C does not lead to ashes agglomeration. The conducted preliminary researches showed prospects of utilization of coal waste by granulation method in mix with natural peat.

  8. Low technology high tritium breeding blanket concept

    International Nuclear Information System (INIS)

    Gohar, Y.; Baker, C.C.; Smith, D.L.

    1987-10-01

    The main function of this low technology blanket is to produce the necessary tritium for INTOR operation with minimum first wall coverage. The INTOR first wall, blanket, and shield are constrained by the dimensions of the reference design and the protection criteria required for different reactor components and dose equivalent after shutdown in the reactor hall. It is assumed that the blanket operation at commercial power reactor conditions and the proper temperature for power generation can be sacrificed to achieve the highest possible tritium breeding ratio with minimum additional research and developments and minimal impact on reactor design and operation. A set of blanket evaluation criteria has been used to compare possible blanket concepts. Six areas: performance, operating requirements, impact on reactor design and operation, safety and environmental impact, technology assessment, and cost have been defined for the evaluation process. A water-cooled blanket was developed to operate with a low temperature and pressure. The developed blanket contains a 24 cm of beryllium and 6 cm of solid breeder both with a 0.8 density factor. This blanket provides a local tritium breeding ratio of ∼2.0. The water coolant is isolated from the breeder material by several zones which eliminates the tritium buildup in the water by permeation and reduces the changes for water-breeder interaction. This improves the safety and environmental aspects of the blanket and eliminates the costly process of the tritium recovery from the water. 12 refs., 13 tabs

  9. Radioactive fallout nuclides in a peat-bog ecosystem

    International Nuclear Information System (INIS)

    Pausch, G.; Hofmann, W.; Steger, F.; Tuerk, R.

    1996-01-01

    The Province of Salzburg belongs to the regions with the highest contamination from the Chernobyl-fallout outside the former USSR. The peat-bog investigated in this study is situated in Koppl, east of Salzburg. A peat-bog is a special example of an ecosystem, which is generally not disturbed by human activities because it is under strict nature-conservation and whose soil structure is not affected by animal activities from moles and earthworms. Peat-bogs are characterized by acidic soils which are high in organic material and low in clay mineral content. A number of previous studies have demonstrated that especially in peat-bogs and especially in the Koppl-peat-bog very high amounts of radioactive fallout nuclides from the Chernobyl accident and from the bomb-testings could be found

  10. Tritium transport analysis for CFETR WCSB blanket

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Pinghui, E-mail: phzhao@mail.ustc.edu.cn; Yang, Wanli; Li, Yuanjie; Ge, Zhihao; Nie, Xingchen; Gao, Zhongping

    2017-01-15

    Highlights: • A simplified tritium transport model for CFETR WCSB blanket was developed. • Tritium transport process in CFETR WCSB blanket was analyzed. • Sensitivity analyses of tritium transport parameters were carried out. - Abstract: Water Cooled Solid Breeder (WCSB) blanket was put forward as one of the breeding blanket candidate schemes for Chinese Fusion Engineering Test Reactor (CFETR). In this study, a simplified tritium transport model was developed. Based on the conceptual engineering design, neutronics and thermal-hydraulic analyses of CFETR WCSB blanket, tritium transport process was analyzed. The results show that high tritium concentration and inventory exist in primary water loop and total tritium losses exceed CFETR limits under current conditions. Conducted were sensitivity analyses of influential parameters, including tritium source, temperature, flow-rate capacity and surface condition. Tritium performance of WCSB blanket can be significantly improved under a smaller tritium impinging rate, a larger flow-rate capacity or a better surface condition. This work provides valuable reference for the enhancement of tritium transport behavior in CFETR WCSB blanket.

  11. Blanket comparison and selection study. Volume I

    International Nuclear Information System (INIS)

    1983-10-01

    The objectives of the Blanket Comparison and Selection Study (BCSS) can be stated as follows: (1) Define a small number (approx. 3) of blanket design concepts that should be the focus of the blanket R and D program. A design concept is defined by the selection of all materials (e.g., breeder, coolant, structure and multiplier) and other major characteristics that significantly influence the R and D requirements. (2) Identify and prioritize the critical issues for the leading blanket concepts. (3) Provide the technical input necessary to develop a blanket R and D program plan. Guidelines for prioritizing the R and D requirements include: (a) critical feasibility issues for the leading blanket concepts will receive the highest priority, and (b) for equally important feasibility issues, higher R and D priority will be given to those that require minimum cost and short time

  12. Characterization of the effects of continuous salt processing on the performance of molten salt fusion breeder blankets

    International Nuclear Information System (INIS)

    Patterson-Hine, F.A.

    1984-05-01

    Several continuous salt processing options are available for use in molten salt fusion breeder blanket designs. The effects of processing on blanket performance have been assessed for three levels of processing and various equilibrium uranium concentrations in the salt. A one-dimensional model of the blanket was used in the neutronics analysis which incorporated transport calculations with time-dependent isotope generation and depletion calculations. The level of salt processing was found to have little effect on the behavior of the blanket during reactor operation; however, significant effects were observed during the decay period after reactor shutdown

  13. Trade-off study of liquid metal self-cooled blankets

    International Nuclear Information System (INIS)

    Gohar, Y.

    1986-01-01

    A trade-off study of liquid metal self-cooled blankets was carried out to define the performance of these blankets and to determine the potential to operate at the maximum possible values of the performance parameters. The main parameters considered during the course of this study were the tritium breeding ratio (TBR), the blanket energy multiplication factor, the energy fraction lost to the shield, the lithium-6 enrichment in the breeder material, the total blanket thickness, the reflector material selection, and the compositions of the different blanket zones. The primary results of the study are as follows: a) the lithium-lead blanket achieves a higher TBR with a smaller blanket thickness relative to the lithium blanket; b) the lithium blanket generates more energy per fusion neutron relative to the lithium-lead blanket; c) among the possible reflector materials, the carbon reflector produces the highest TBR; d) the high-Z reflector materials (Mo, Cu, W, or steel) generate more energy per fusion neutron and produce smaller TBRs relative to the carbon reflector; e) lithium-6 enrichment is required for the lithium-lead blanket to reduce the total blanket thickness; and f) the energy deposition per fusion neutron reaches a saturation as the blanket thickness, the fraction of the high-Z material in the reflector, or the reflector zone thickness increases (this allows one to design the blanket for a specific TBR without reducing the energy production)

  14. Industrial peat utilization and its importance to the Irish economy

    International Nuclear Information System (INIS)

    Bradley, Thomas

    1995-01-01

    Over the centuries peat has been used as a valuable source of fuel for domestic heating and cooking. In contrast to earlier times when all peat extraction and harvesting was carried out by hand, peat production in Ireland to-day has become a highly mechanised, large scale commercial industry, making a significant contribution to the Irish economy. Bord na Mona, the state agency assigned the responsibility for peatland development in Ireland, has developed 88,000 hectares of Ireland's 1.2 million hectares of peatlands. Over 5.2 million tonnes of fuel peat are currently sold each year for electricity generation and for the manufacture of peat briquettes for heating installations. With the introduction of a new 120 MW peat fired power station, the overall sales for fuel peat will be increased by 1.0 million tonnes per annum. On the horticultural front, Bord na Mona produces and sells over 1.5 million cubic metres of horticultural peat products to the domestic and international markets. (author)

  15. The blanket interface to TSTA

    International Nuclear Information System (INIS)

    Clemmer, R.G.; Finn, P.A.; Grimm, T.L.; Sze, D.K.; Anderson, J.L.; Bartlit, J.R.; Naruse, Y.; Yoshida, H.

    1988-01-01

    The requirements of tritium technology are centered in three main areas, (1) fuel processing, (2) breeder tritium extraction, and (3) tritium containment. The Tritium Systems Test Assembly (TSTA) now in operation at Los Alamos National Laboratory (LANL) is dedicated to developing and demonstrating the tritium technology for fuel processing and containment. TSTA is the only fusion fuel processing facility that can operate in a continuous closed-loop mode. The tritium throughput of TSTA is 1000 g/d. However, TSTA does not have a blanket interface system. The authors have initiated a study to define a Breeder Blanket Interface (BBIO) for TSTA. The first step of the work is to define the condition of the gaseous tritium stream from the blanket tritium recovery system. This report summarizes this part of the work for one particular blanket concept, i.e., a self-cooled lithium blanket. The total gas throughput, the hydrogen to tritium ratio, the corrosive chemicals, and the radionuclides are defined. Various methods of tritium recovery from liquid lithium were assessed: yttrium gettering, permeation windows, and molten salt extraction. The authors' evaluation concluded that the best method was molten salt extraction

  16. Contribution to the development of peat-bog and history of landscape in the Havellaendische Luch

    International Nuclear Information System (INIS)

    Mundel, G.; Trettin, R.; Hiller, A.

    1983-01-01

    By means of the 14 C method a low-bog profile of the Havellaendische Luch measuring 200 cm in depth was dated systematically. The peat formation had started as early as at the end of the late-glacial. Approximately 6000 years ago a stagnation of bog growth had occured and then about 3700 years ago a stronger bog growth had begun again. The change in peat components and thereby in the geological structure is largely attributed to different ground water levels. According to the relatively low total thickness the annual mean rates of accumulation are small. In muddy soils, values between 0.2 and 1.2 mm were ascertained. In peat soils these values are still smaller. But here it is a question of remainders of the protogenic peat formation. As a result of former or recent mineralization the original peat substance has been diminished. (author)

  17. Relationship between peat geochemistry and depositional environments, Cranberry Island, Maine

    Science.gov (United States)

    Raymond, R.; Cameron, C.C.; Cohen, A.D.

    1987-01-01

    The Heath, Great Cranberry Island, Maine, offers a unique locality for studying lateral and vertical relationships between radically different peat types within 1 km2. The majority of The Heath is a Sphagnum moss-dominated raised bog. Surrounding the raised bog is a swamp/marsh complex containing grass, sedge, Sphagnum moss, alder, tamarack, and skunk cabbage. Swamp/ marsh-deposited peat occurs both around the margins of The Heath and under Sphagnum-dominated peat, which was deposited within the raised bog. A third peat type, dominated by herbaceous aquatics, is present underlying the swamp/marsh-dominated peat but is not present as a dominant botanical community of The Heath. The three peat types have major differences in petrographic characteristics, ash contents, and associated minerals. Sulfur contents range from a low of 0.19 wt.% (dry) within the raised bog to a high of 4.44 wt% (dry) near the west end of The Heath, where swamp/marsh peat occurring directly behind a storm beach berm has been influenced by marine waters. The presence of major geochemical variations within a 1-km2 peat deposit suggests the need for in-depth characterization of potential peat resources prior to use. ?? 1987.

  18. Structure of peat soils and implications for biogeochemical processes and hydrological flow

    Science.gov (United States)

    Rezanezhad, F.; McCarter, C. P. R.; Gharedaghloo, B.; Kleimeier, C.; Milojevic, T.; Liu, H.; Weber, T. K. D.; Price, J. S.; Quinton, W. L.; Lenartz, B.; Van Cappellen, P.

    2017-12-01

    Permafrost peatlands contain globally important amounts of soil organic carbon and play major roles in global water, nutrient and biogeochemical cycles. The structure of peatland soils (i.e., peat) are highly complex with unique physical and hydraulic properties; where significant, and only partially reversible, shrinkage occurs during dewatering (including water table fluctuations), compression and/or decomposition. These distinct physical and hydraulic properties controls water flow, which in turn affect reactive and non-reactive solute transport (such as, sorption or degradation) and biogeochemical functions. Additionally, peat further attenuates solute migration through molecular diffusion into the inactive pores of Sphagnum dominated peat. These slow, diffusion-limited solute exchanges between the pore regions may give rise to pore-scale chemical gradients and heterogeneous distributions of microbial habitats and activity in peat soils. Permafrost peat plateaus have the same essential subsurface characteristics as other widely organic soil-covered peatlands, where the hydraulic conductivity is related to the degree of decomposition and soil compression. Increasing levels of decomposition correspond with a reduction of effective pore diameter and consequently restrict water and solute flow (by several orders of magnitude in hydraulic conductivity between the ground surface and a depth of 50 cm). In this presentation, we present the current knowledge of key physical and hydraulic properties related to the structure of globally available peat soils and discuss their implications for water storage, flow and the migration of solutes.

  19. The Role of Peat Layers on Iron Dynamics in Peatlands

    Directory of Open Access Journals (Sweden)

    Arifin Fahmi

    2010-09-01

    Full Text Available The research aimed to study the effect of peat thickness and humification stage of the peat material on Fe solubility at the peatlands with sulfidic material as substratum. The research was conducted at three conditionals of ombrogen peatlands ie ; deep, moderate and shallow peat. Soil samples were collected by using peat borer according to interlayer (the border layer of peat and mineral layer and conditional of soil horizons. The sample point depth were (cm G.s2 : 25, G.s1 : 50, Int.s : 70, M.s1 : 90 and M.s2 : 100 for shallow peat, G.m2 : 47, G.m1 : 100, Int.m : 120 and M.m1 : 135 for moderate peat and G.d3 : 50, G.d2 : 150, G.d1 : 200, Int.d : 220 and M.d1 : 235 for deep peat respectively. The results showed that most of Fe on the tested soils was found in organic forms. The peat layers above the sulfidic material decreased the Fe2+ solubility at peatlands. Fe2+ concentration in peat layer decreased with its increasing distance from sulfidic material. There was any other processes beside complexation and chelation of Fe2+ by humic material and its processes was reduction of Fe3+ and this conditions was reflected in redox potential values (Eh.

  20. Convertible shielding to ceramic breeding blanket

    International Nuclear Information System (INIS)

    Furuya, Kazuyuki; Kurasawa, Toshimasa; Sato, Satoshi; Nakahira, Masataka; Togami, Ikuhide; Hashimoto, Toshiyuki; Takatsu, Hideyuki; Kuroda, Toshimasa.

    1995-05-01

    Four concepts have been studied for the ITER convertible blanket: 1)Layered concept 2)BIT(Breeder-Inside-Tube)concept 3)BOT(Breeder-Out of-Tube)concept 4)BOT/mixed concept. All concepts use ceramic breeder and beryllium neutron multiplier, both in the shape of small spherical pebbles, 316SS structure, and H 2 O coolant (inlet/outlet temperatures : 100/150degC, pressure : 2 MPa). During the BPP, only beryllium pebbles (the primary pebble in case of BOT/mixed concept) are filled in the blanket for shielding purpose. Then, before the EPP operation, breeder pebbles will be additionally inserted into the blanket. Among possible conversion methods, wet method by liquid flow seems expecting for high and homogeneous pebble packing. Preliminary 1-D neutronics calculation shows that the BOT/mixed concept has the highest breeding and shielding performance. However, final selection should be done by R and D's and more detail investigation on blanket characteristics and fabricability. Required R and D's are also listed. With these efforts, the convertible blanket can be developed. However, the following should be noted. Though many of above R and D's are also necessary even for non-convertible blanket, R and D's on convertibility will be one of the most difficult parts and need significant efforts. Besides the installation of convertible blanket with required structures and lines for conversion will make the ITER basic machine more complicated. (author)

  1. Classification Using Markov Blanket for Feature Selection

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Luo, Jian

    2009-01-01

    Selecting relevant features is in demand when a large data set is of interest in a classification task. It produces a tractable number of features that are sufficient and possibly improve the classification performance. This paper studies a statistical method of Markov blanket induction algorithm...... for filtering features and then applies a classifier using the Markov blanket predictors. The Markov blanket contains a minimal subset of relevant features that yields optimal classification performance. We experimentally demonstrate the improved performance of several classifiers using a Markov blanket...... induction as a feature selection method. In addition, we point out an important assumption behind the Markov blanket induction algorithm and show its effect on the classification performance....

  2. Uranium/thorium dating of Late Pleistocene peat deposits in NW Europe, uranium/thorium isotope systematics and open-system behaviour of peat layers

    NARCIS (Netherlands)

    Heijnis, H.; Plicht, J. van der

    1992-01-01

    The possibility of dating peat by the uranium-series disequilibrium method is discussed. In principle, this method can be used to date peat to approximately 350 ka. The application of the U/Th disequilibrium method (UTD) on peat provides us with the probability of constructing a new chronology for

  3. The association of uranium with organic matter in peat and peat water in a wetland from the Carson Range, Nevada

    International Nuclear Information System (INIS)

    Orem, W.; Zielinski, R.; Otton, J.; Lerch, H.

    1992-01-01

    Uranium has a high affinity for organic matter and is frequently found in high concentrations in coal and peat beds. The nature of the U/organic matter association was investigated in peat from cores obtained from a small wetland (Upper Zephyr Fen) near Lake Tahoe, NV. The peat contains U concentrations of up to 0.5% dry weight, supplied by surface and ground water weathering the U-rich granodiorite rocks of the surrounding mountains. Uranium concentrations are highly correlated with both organic C and N contents, but show no apparent relationship to specific organic moieties such as carboxyl or phenolic functional groups. Sieve studies of the peat show the U is concentrated in the 2,000--250 um size fraction. This fraction also has the lowest atomic C/N ratio, suggesting a possible role of N-containing organic compounds in U complexation. In peat pore waters, dissolved U is primarily associated with high molecular weight dissolved organic matter, as shown by equilibrium models and experimental data

  4. Test Blanket Working Group's recent activities

    International Nuclear Information System (INIS)

    Vetter, J.E.

    2001-01-01

    The ITER Test Blanket Working Group (TBWG) has continued its activities during the period of extension of the EDA with a revised charter on the co-ordination of the development work performed by the Parties and by the JCT leading to a co-ordinated test programme on ITER for a DEMO-relevant tritium breeding blanket. This follows earlier work carried out until July 1998, which formed part of the ITER Final Design Report (FDR), completed in 1998. Whilst the machine parameters for ITER-FEAT have been significantly revised compared to the FDR, testing of breeding blanket modules remains a main objective of the test programme and the development of a reactor-relevant breeding blanket to ensure tritium fuel self-sufficiency is recognized a key issue for fusion. Design work and R and D on breeding blanket concepts, including co-operation with the other Contacting Parties of the ITER-EDA for testing these concepts in ITER, are included in the work plans of the Parties

  5. IR-spectroscopy as an analytical method for identification of horticultural peat

    International Nuclear Information System (INIS)

    Lehtovaara, J.; Herranen, M.; Nyroenen, T.; MacDonald, A.

    1988-01-01

    The process of selecting different peat types for horticultural purposes involves many physical and chemical determinations. Infrared spectroscopy could be used together with the usual methods for the evaluation of peat quality. Due to the fact that different peats contain different amounts of infrared absorbing functional groups, each peat produces a characteristic spectrum. From the spectrum, one may determine the botanical composition, degree of humification, ash content, cation exchange capacity, nitrogen content and carbon content, of the natural peat. The spectrum also shows whether the peat has been fertilized and limed and in some cases the presence of mineral soil or wetting agent mixed in the peat may be detected

  6. Achievements of element technology development for breeding blanket

    International Nuclear Information System (INIS)

    Enoeda, Mikio

    2005-03-01

    Japan Atomic Energy Research Institute (JAERI) has been performing the development of breeding blanket for fusion power plant, as a leading institute of the development of solid breeder blankets, according to the long-term R and D program of the blanket development established by the Fusion Council of Japan in 1999. This report is an overview of development plan, achievements of element technology development and future prospect and plan of the development of the solid breeding blanket in JAERI. In this report, the mission of the blanket development activity in JAERI, key issues and roadmap of the blanket development have been clarified. Then, achievements of the element technology development were summarized and showed that the development has progressed to enter the engineering testing phase. The specific development target and plan were clarified with bright prospect. Realization of the engineering test phase R and D and completion of ITER test blanket module testing program, with universities/NIFS cooperation, are most important steps in the development of breeding blanket of fusion power demonstration plant. (author)

  7. Methodology for accident analyses of fusion breeder blankets and its application to helium-cooled pebble bed blanket

    International Nuclear Information System (INIS)

    Panayotov, Dobromir; Grief, Andrew; Merrill, Brad J.; Humrickhouse, Paul; Trow, Martin; Dillistone, Michael; Murgatroyd, Julian T.; Owen, Simon; Poitevin, Yves; Peers, Karen; Lyons, Alex; Heaton, Adam; Scott, Richard

    2016-01-01

    Graphical abstract: - Highlights: • Test Blanket Systems (TBS) DEMO breeding blankets (BB) safety demonstration. • Comprehensive methodology for fusion breeding blanket accident analysis that addresses the specificity of the breeding blanket designs, materials, and phenomena. • Development of accident analysis specifications (AAS) via the use of phenomena identification and ranking tables (PIRT). • PIRT application to identify required physical models for BB accidents analysis, code assessment and selection. • Development of MELCOR and RELAP5 codes TBS models. • Qualification of the models via comparison with finite element calculations, code-tocode comparisons, and sensitivity studies. - Abstract: ‘Fusion for Energy’ (F4E) is designing, developing, and implementing the European Helium-Cooled Lead-Lithium (HCLL) and Helium-Cooled Pebble-Bed (HCPB) Test Blanket Systems (TBSs) for ITER (Nuclear Facility INB-174). Safety demonstration is an essential element for the integration of these TBSs into ITER and accident analysis is one of its critical components. A systematic approach to accident analysis has been developed under the F4E contract on TBS safety analyses. F4E technical requirements, together with Amec Foster Wheeler and INL efforts, have resulted in a comprehensive methodology for fusion breeding blanket accident analysis that addresses the specificity of the breeding blanket designs, materials, and phenomena while remaining consistent with the approach already applied to ITER accident analyses. The methodology phases are illustrated in the paper by its application to the EU HCPB TBS using both MELCOR and RELAP5 codes.

  8. Methodology for accident analyses of fusion breeder blankets and its application to helium-cooled pebble bed blanket

    Energy Technology Data Exchange (ETDEWEB)

    Panayotov, Dobromir, E-mail: dobromir.panayotov@f4e.europa.eu [Fusion for Energy (F4E), Josep Pla, 2, Torres Diagonal Litoral B3, Barcelona E-08019 (Spain); Grief, Andrew [Amec Foster Wheeler, Booths Park, Chelford Road, Knutsford WA16 8QZ, Cheshire (United Kingdom); Merrill, Brad J.; Humrickhouse, Paul [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID (United States); Trow, Martin; Dillistone, Michael; Murgatroyd, Julian T.; Owen, Simon [Amec Foster Wheeler, Booths Park, Chelford Road, Knutsford WA16 8QZ, Cheshire (United Kingdom); Poitevin, Yves [Fusion for Energy (F4E), Josep Pla, 2, Torres Diagonal Litoral B3, Barcelona E-08019 (Spain); Peers, Karen; Lyons, Alex; Heaton, Adam; Scott, Richard [Amec Foster Wheeler, Booths Park, Chelford Road, Knutsford WA16 8QZ, Cheshire (United Kingdom)

    2016-11-01

    Graphical abstract: - Highlights: • Test Blanket Systems (TBS) DEMO breeding blankets (BB) safety demonstration. • Comprehensive methodology for fusion breeding blanket accident analysis that addresses the specificity of the breeding blanket designs, materials, and phenomena. • Development of accident analysis specifications (AAS) via the use of phenomena identification and ranking tables (PIRT). • PIRT application to identify required physical models for BB accidents analysis, code assessment and selection. • Development of MELCOR and RELAP5 codes TBS models. • Qualification of the models via comparison with finite element calculations, code-tocode comparisons, and sensitivity studies. - Abstract: ‘Fusion for Energy’ (F4E) is designing, developing, and implementing the European Helium-Cooled Lead-Lithium (HCLL) and Helium-Cooled Pebble-Bed (HCPB) Test Blanket Systems (TBSs) for ITER (Nuclear Facility INB-174). Safety demonstration is an essential element for the integration of these TBSs into ITER and accident analysis is one of its critical components. A systematic approach to accident analysis has been developed under the F4E contract on TBS safety analyses. F4E technical requirements, together with Amec Foster Wheeler and INL efforts, have resulted in a comprehensive methodology for fusion breeding blanket accident analysis that addresses the specificity of the breeding blanket designs, materials, and phenomena while remaining consistent with the approach already applied to ITER accident analyses. The methodology phases are illustrated in the paper by its application to the EU HCPB TBS using both MELCOR and RELAP5 codes.

  9. Peat compaction in deltas : implications for Holocene delta evolution

    NARCIS (Netherlands)

    van Asselen, S.

    2010-01-01

    Many deltas contain substantial amounts of peat, which is the most compressible soil type. Therefore, peat compaction potentially leads to high amounts of subsidence in deltas. The main objective of this research was to quantify subsidence due to peat compaction in Holocene fluvial-deltaic settings

  10. Design study of blanket structure for tokamak experimental fusion reactor

    International Nuclear Information System (INIS)

    1979-11-01

    Design study of the blanket structure for JAERI Experimental Fusion Reactor (JXFR) has been carried out. Studied here were fabrication and testing of the blanket structure (blanket cells, blanket rings, piping and blanket modules), assembly and disassembly of the blanket module, and monitering and testing technique. Problems in design and fabrication of the blanket structure could be revealed. Research and development problems for the future were also disclosed. (author)

  11. Occurrence and origin of carbohydrates in peat samples from a red mangrove environment as reflected by abundances of neutral monosaccharides

    Science.gov (United States)

    Moers, M. E. C.; Baas, M.; De Leeuw, J. W.; Boon, J. J.; Schenck, P. A.

    1990-09-01

    Acid hydrolysates of fractionated red mangrove peat samples and handpicked roots and rootlets of Rhizophora mangle (red mangrove) from Jewfish Key in the Florida Everglades were analysed for neutral monosaccharides. In the peat samples two major sources of carbohydrates could be determined: (1) vascular plant carbohydrates derived from Rhizophora mangle and (2) microbially derived carbohydrates. Significant correlations exist between the relative contributions of most neutral monosaccharides and the total carbohydrate concentration. The fine-grained peat fractions yielded low total neutral monosaccharides whose distributions indicate contributions of microbial carbohydrates. The coarse-grained peat samples yielded high total neutral monosaccharides with distributions indicating major contributions of vascular plant carbohydrates. It is estimated that a substantial part of the sugars analysed in the finegrained samples originates from microorganisms ([cyano] bacteria, algae).The absence of a trend in total neutral monosaccharide concentrations with depth suggests that microbial degradation is limited to the upper levels of the peat and that the microbial sugars determined at lower peat levels are derived from nonviable or dormant microorganisms. Results from factor analysis may suggest differences in microbial populations in the various peat samples.

  12. ITER breeding blanket module design and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Toshimasa; Enoeda, Mikio; Kikuchi, Shigeto [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

    1998-11-01

    The ITER breeding blanket employs a ceramic breeder and Be neutron multiplier both in small spherical pebble form. Radial-poloidal cooling panels are arranged in the blanket box to remove the nuclear heating in these materials and to reinforce the blanket structure. At the first wall, Be armor is bonded onto the stainless steel (SS) structure to provide a low Z plasma-compatible surface and to protect the first wall/blanket structure from the direct contact with the plasma during off-normal events. Thermo-mechanical analyses and investigation of fabrication procedure have been performed for this breeding blanket. To evaluate thermo-mechanical behavior of the pebble beds including the dependency of the effective thermal conductivity on stress, analysis methods have been preliminary established by the use of special calculation option of ABAQUS code, which are briefly summarized in this report. The structural response of the breeding blanket module under internal pressure of 4 MPa (in case of in-blanket LOCA) resulted in rather high stress in the blanket side (toroidal end) wall, thus addition of a stiffening rib or increase of the wall thickness will be needed. Two-dimensional elasto-plastic analyses have been performed for the Be/SS bonded interface at the first wall taking a fabrication process based on HIP bonding and thermal cycle due to pulsed plasma operation into account. The stress-strain hysteresis during these process and operation was clarified, and a procedure to assess and/or confirm the bonding integrity was also proposed. Fabrication sequence of the breeding blanket module was preliminarily developed based on the procedure to fabricate part by part and to assemble them one by one. (author)

  13. Long-term disturbance dynamics and resilience of tropical peat swamp forests.

    Science.gov (United States)

    Cole, Lydia E S; Bhagwat, Shonil A; Willis, Katherine J

    2015-01-01

    1. The coastal peat swamp forests of Sarawak, Malaysian Borneo, are undergoing rapid conversion, predominantly into oil palm plantations. This wetland ecosystem is assumed to have experienced insignificant disturbance in the past, persisting under a single ecologically-stable regime. However, there is limited knowledge of the past disturbance regime, long-term functioning and fundamentally the resilience of this ecosystem to changing natural and anthropogenic perturbations through time. 2. In this study, long-term ecological data sets from three degraded peatlands in Sarawak were collected to shed light on peat swamp forest dynamics. Fossil pollen and charcoal were counted in each sedimentary sequence to reconstruct vegetation and investigate responses to past environmental disturbance, both natural and anthropogenic. 3. Results demonstrate that peat swamp forest taxa have dominated these vegetation profiles throughout the last c . 2000-year period despite the presence of various drivers of disturbance. Evidence for episodes of climatic variability, predominantly linked to ENSO events, and wildfires is present throughout. However, in the last c . 500 years, burning and indicators of human disturbance have elevated beyond past levels at these sites, concurrent with a reduction in peat swamp forest pollen. 4. Two key insights have been gained through this palaeoecological analysis: (i) peat swamp forest vegetation has demonstrated resilience to disturbance caused by burning and climatic variability in Sarawak in the late Holocene, however (ii) coincident with increased fire combined with human impact c . 500 years ago, these communities started to decline. 5. Synthesis . Sarawak's coastal peat swamps have demonstrated resilience to past natural disturbances, with forest vegetation persisting through episodes of fire and climatic variability. However, palaeoecological data presented here suggest that recent, anthropogenic disturbances are of a greater magnitude

  14. APT target-blanket fabrication development

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.L.

    1997-06-13

    Concepts for producing tritium in an accelerator were translated into hardware for engineering studies of tritium generation, heat transfer, and effects of proton-neutron flux on materials. Small-scale target- blanket assemblies were fabricated and material samples prepared for these performance tests. Blanket assemblies utilize composite aluminum-lead modules, the two primary materials of the blanket. Several approaches are being investigated to produce large-scale assemblies, developing fabrication and assembly methods for their commercial manufacture. Small-scale target-blanket assemblies, designed and fabricated at the Savannah River Site, were place in Los Alamos Neutron Science Center (LANSCE) for irradiation. They were subjected to neutron flux for nine months during 1996-97. Coincident with this test was the development of production methods for large- scale modules. Increasing module size presented challenges that required new methods to be developed for fabrication and assembly. After development, these methods were demonstrated by fabricating and assembling two production-scale modules.

  15. Construction of Infrastructure on Peat: Case Studies and Lessons Learned

    Directory of Open Access Journals (Sweden)

    Hua Ling Jen

    2016-01-01

    Full Text Available Construction of infrastructures on peat land is a very challenging task due to its properties of low shear strength, high compressibility and high water content. This paper summarizes various solutions which could be adopted for the construction of infrastructure on peat, as reviewed by the experts and panels during IConCEES International Workshop 2015. Engineers could (a avoid peat, such as to transfer the load to the hard layers through end bearing piles or to replace the peat with the other soils, or (b construct on peat with special precautions, such as by reducing the weight of the construction materials and dewatering the peat to improve the engineering properties. This paper serves to generate new ideas and give insights of the problems commonly encountered by the industry. Some of the proposed solutions might never be tested on peat. This would rely on the researchers to take up the challenge to further investigate and address the technical issues outlined in this paper.

  16. On blanket concepts of the Helias reactor

    International Nuclear Information System (INIS)

    Wobig, H.; Harmeyer, E.; Herrnegger, F.; Kisslinger, J.

    1999-07-01

    The paper discusses various options for a blanket of the Helias reactor HSR22. The Helias reactor is an upgrade version of the Wendelstein 7-X device. The dimensions of the Helias reactor are: major radius 22 m, average plasma radius 1.8 m, magnetic field on axis 4.75 T, maximum field 10 T, number of field periods 5, fusion power 3000 MW. The minimum distance between plasma and coils is 1.5 m, leaving sufficient space for a blanket and shield. Three options of a breeding blanket are discussed taking into account the specific properties of the Helias configuration. Due to the large area of the first wall (2600 m 2 ) the average neutron power load on the first wall is below 1 MWm .2 , which has a strong impact on the blanket performance with respect to lifetime and cooling requirements. A comparison with a tokamak reactor shows that the lifetime of first wall components and blanket components in the Helias reactor is expected to be at least two times longer. The blanket concepts being discussed in the following are: the solid breeder concept (HCPB), the dual-coolant Pb-17Li blanket concept and the water-cooled Pb-17Li concept (WCLL). (orig.)

  17. Neutronics-processing interface analyses for the Accelerator Transmutation of Waste (ATW) aqueous-based blanket system

    International Nuclear Information System (INIS)

    Davidson, J.W.; Battat, M.E.

    1993-01-01

    Neutronics-processing interface parameters have large impacts on the neutron economy and transmutation performance of an aqueous-based Accelerator Transmutation of Waste (ATW) system. A detailed assessment of the interdependence of these blanket neutronic and chemical processing parameters has been performed. Neutronic performance analyses require that neutron transport calculations for the ATW blanket systems be fully coupled with the blanket processing and include all neutron absorptions in candidate waste nuclides as well as in fission and transmutation products. The effects of processing rates, flux levels, flux spectra, and external-to-blanket inventories on blanket neutronic performance were determined. In addition, the inventories and isotopics in the various subsystems were also calculated for various actinide and long-lived fission product transmutation strategies

  18. The emissions of peat production and utilization chain, the effects of the emissions, proportion and valuing of them

    International Nuclear Information System (INIS)

    Ahonen, A.; Leiviskae, V.; Kiukaanniemi, E.

    1992-01-01

    The solid matter flush off of peat production areas do not differ remarkably from those of forest drainage and clear felling excluding the nitrogen flush out, which remain on higher level longer, for the 15-20 years of peat production. The fertilizer flush off of peat production is remarkably smaller than that of agriculture. The portion of peat of the total N-load in Finnish watercourses is 0.3 % and 0.2 % of the P-load. The low load value of peat production is due to the marginality of peat production areas of the total utilization of the ground. The portion of loads of peat production are increased on those areas there the portion of peat production of the total ground utilization is high, and no other water loading activities except forestry does not exist. The portion of peat of the total primary energy consumption is about 5 %. The portion of peat fuelled boilers of the solid matter, SO2 and NOx emissions of the energy production was 3 % and of CO2 emissions 8 % in 1991. The CO2 emissions of peat production and combustion into the air are about 360 k/produced m 3 . Some of the environmental effects of the peat production and utilization can be priced using market prices, and hence it is easy to estimate their costs if the reason-action connections are known. Others, like health effects and the conservational value of the mire, are very hard to prize. The estimation of environmental effects cause problems in valoring. the effects of peat production load to watercourses are not easy to separate from the effects of other loads on water courses

  19. Proceedings: 7th international peat congress. Vols. 1, 2, 3, and 4

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Proceedings from a conference on peat published in four volumes. These comprise six different sections: survey, classification, ecology and conservation of peatlands; winning, harvesting, storage, transportation and processing of peat and sapropel for industrial, agricultural and horticultural purposes; bog cultivation and peatland forestry - the use of peat, peat products, and sapropel in agriculture and horticulture; chemistry, physics, biochemistry and microbiology of peat and sapropel - production and utilization of physiologically active substances, growth stimulators, medical preparations and related material; terminology, notation, and standardization of peat products; and peat balneology and therapeutics.

  20. Factors controlling peat chemistry and vegetation composition in Sudbury peatlands after 30 years of pollution emission reductions

    International Nuclear Information System (INIS)

    Barrett, Sophie E.; Watmough, Shaun A.

    2015-01-01

    The objective of this research was to assess factors controlling peat and plant chemistry, and vegetation composition in 18 peatlands surrounding Sudbury after more than 30 years of large (>95%) pollution emission reductions. Sites closer to the main Copper Cliff smelter had more humified peat and the surface horizons were greatly enriched in copper (Cu) and nickel (Ni). Copper and Ni concentrations in peat were significantly correlated with that in the plant tissue of Chamaedaphne calyculata. The pH of peat was the strongest determining factor for species richness, diversity, and community composition, although percent vascular plant cover was strongly negatively correlated with surface Cu and Ni concentrations in peat. Sphagnum frequency was also negatively related to peat Cu and Ni concentrations indicating sites close to Copper Cliff smelter remain adversely impacted by industrial activities. - Highlights: • Surface peat in wetlands in Sudbury is contaminated with Cu and Ni. • The pH of peat is positively related to species richness and diversity. • Metal levels in peat is negatively related to vascular vegetation and Sphagnum cover. • Loss of Sphagnum at contaminated peatlands may impede recovery. - Sudbury peatlands remain impacted by industrial activities as indicated by elevated copper and nickel concentrations and diminished vascular plant cover and Sphagnum frequency.

  1. Pollution abatement with peat onsite wastewater treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, J L [University of Maine, Orano, ME (United States). Dept. of Civil Engineering

    1994-02-01

    The purpose of onsite wastewater treatment is to provide economical removal of dissolved nutrients, pathogens and other contaminates from septic tank effluent to avoid the pollution of groundwater or creation of other health hazards. The effective use of conventional soil adsorption systems is limited by a number of factors including site characteristics, soil type and condition, and the proximity of the system to surface waters or a source of potable water. On adverse sites, where the use of conventional subsurface soil adsorption systems does not provide acceptable levels of treatment, Sphagnum peat may be used as an economical method of onsite wastewater treatment. The peat system, when properly designed and constructed, is relatively simple to install, requires minimal energy and maintenance, and provides a high quality effluent without additional disinfection. 19 refs.

  2. Magnetoconvection in HCLL blankets

    International Nuclear Information System (INIS)

    Mistrangelo, C.; Buehler, L.

    2014-01-01

    In the present work we consider magneto-convective flows in one of the proposed European liquid metal blankets that will be tested in the experimental fusion reactor ITER. Here the PbLi alloy is used as breeder material and helium as coolant. In order to finalize the design of the helium cooled lead lithium (HCLL) blanket, studies are still required to fully understand the behavior of the electrically conducting breeder under the influence of the intense magnetic field that confines the fusion plasma and in case of non-uniform thermal conditions. Liquid metal HCLL blanket flows are expected to be mainly driven by buoyancy forces caused by non-isothermal operating conditions due to neutron volumetric heating and cooling of walls, since only a weak forced ow is foreseen for tritium extraction in external ancillary systems. Buoyancy can therefore become very important and modify the velocity distribution and related heat transfer performance of the blanket. The present numerical study aims at clarifying the influence of electromagnetic and thermal coupling of neighboring fluid domains on magneto-convective flows in geometries relevant for the HCLL blanket concept. According to the last design review two internal cooling plates subdivide the fluid domain into three slender flow regions, which are thermally and electrically coupled through common walls. First a uniform volumetric heat source is considered to identify the basic convective patterns that establish in the liquid metal. Results are then compared with those obtained by applying a realistic radial distribution of the power density as obtained from a neutronic analysis. Velocity and temperature distributions are discussed for various volumetric heat sources and magnetic field strengths.

  3. Radioactivity of peat mud used in therapy.

    Science.gov (United States)

    Karpińska, Maria; Mnich, Krystian; Kapała, Jacek; Bielawska, Agnieszka; Kulesza, Grzegorz; Mnich, Stanisław

    2016-02-01

    The aim of the study was to determine the contents of natural and artificial isotopes in peat mud and to estimate the radiation dose absorbed via skin in patients during standard peat mud treatment. The analysis included 37 samples collected from 8 spas in Poland. The measurements of isotope concentration activity were conducted with the use of gamma spectrometry methods. The skin dose in a standard peat mud bath therapy is approximately 300 nSv. The effective dose of such therapy is considered to be 22 nSv. The doses absorbed during peat mud therapy are 5 orders of magnitude lower than effective annual dose absorbed from the natural radiation background by a statistical Pole (3.5 mSv). Neither therapeutic nor harmful effect is probable in case of such a small dose of ionising radiation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Polyphenols as enzyme inhibitors in different degraded peat soils: Implication for microbial metabolism in rewetted peatlands

    Science.gov (United States)

    Zak, Dominik; Roth, Cyril; Gelbrecht, Jörg; Fenner, Nathalie; Reuter, Hendrik

    2015-04-01

    Recently, more than 30,000 ha of drained minerotrophic peatlands (= fens) in NE Germany were rewetted to restore their ecological functions. Due to an extended drainage history, a re-establishment of their original state is not expected in the short-term. Elevated concentrations of dissolved organic carbon, ammonium and phosphate have been measured in the soil porewater of the upper degraded peat layers of rewetted fens at levels of one to three orders higher than the values in pristine systems; an indicator of increased microbial activity in the upper degraded soil layers. On the other hand there is evidence that the substrate availability within the degraded peat layer is lowered since the organic matter has formerly been subject to intense decomposition over the decades of drainage and intense agricultural use of the areas. Previously however, it was suggested that inhibition of hydrolytic enzymes by polyphenolic substances is suspended during aeration of peat soils mainly due to the decomposition of the inhibiting polyphenols by oxidising enzymes such as phenol oxidase. Accordingly we hypothesised a lack of enzyme inhibiting polyphenols in degraded peat soils of rewetted fens compared to less decomposed peat of more natural fens. We collected both peat samples at the soil surface (0-20 cm) and fresh roots of dominating vascular plants and mosses (as peat parent material) from five formerly drained rewetted sites and five more natural sites of NE Germany and NW Poland. Less decomposed peat and living roots were used to obtain an internal standard for polyphenol analysis and to run enzyme inhibition tests. For all samples we determined the total phenolic contents and in addition we distinguished between the contents of hydrolysable and condensed tannic substances. From a methodical perspective the advantage of internal standards compared to the commercially available standards cyanidin chloride and tannic acid became apparent. Quantification with cyanidin or

  5. Benchmark calculations for fusion blanket development

    International Nuclear Information System (INIS)

    Sawan, M.E.; Cheng, E.T.

    1985-01-01

    Benchmark problems representing the leading fusion blanket concepts are presented. Benchmark calculations for self-cooled Li/sub 17/Pb/sub 83/ and helium-cooled blankets were performed. Multigroup data libraries generated from ENDF/B-IV and V files using the NJOY and AMPX processing codes with different weighting functions were used. The sensitivity of the TBR to group structure and weighting spectrum increases and Li enrichment decrease with up to 20% discrepancies for thin natural Li/sub 17/Pb/sub 83/ blankets

  6. Peat soils stabilization using Effective Microorganisms (EM)

    Science.gov (United States)

    Yusof, N. Z.; Samsuddin, N. S.; Hanif, M. F.; Syed Osman, S. B.

    2018-04-01

    Peat soil is known as geotechnical problematic soil since it is the softest soil having highly organic and moisture content which led to high compressibility, low shear strength and long-term settlement. The aim of this study was to obtain the stabilized peat soils using the Effective Microorganisms (EM). The volume of EM added and mixed with peat soils varied with 2%, 4%, 6%, 8% and 10% and then were cured for 7, 14 and 21 days. The experiment was done for uncontrolled and controlled moisture content. Prior conducting the main experiments, the physical properties such as moisture content, liquid limit, specific gravity, and plastic limit etc. were measure for raw peat samples. The Unconfined Compressive Strength (UCS) test was performed followed by regression analysis to check the effect of EM on the soil strength. Obtained results have shown that the mix design for controlled moisture contents showed the promising improvement in their compressive strength. The peat soil samples with 10% of EM shows the highest increment in UCS value and the percentage of increments are in the range of 44% to 65% after curing for 21 days. The regression analysis of the EM with the soil compressive strength showed that in controlled moisture conditions, EM significantly improved the soil stability as the value of R2 ranged between 0.97 – 0.78. The results have indicated that the addition of EM in peat soils provides significant improving in the strength of the soil as well as the other engineering properties.

  7. Stress analysis of the tokamak engineering test breeder blanket

    International Nuclear Information System (INIS)

    Huang Zhongqi

    1992-01-01

    The design features of the hybrid reactor blanket and main parameters are presented. The stress analysis is performed by using computer codes SAP5p and SAP6 with the three kinds of blanket module loadings, i.e, the pressure of coolant, the blanket weight and the thermal loading. Numerical calculation results indicate that the stresses of the blanket are smaller than the allowable ones of the material, the blanket design is therefore reasonable

  8. Integrated Blanket Supplementary Feeding Program Reduces Levels of Stunting in Yenangyaung, Myanmar

    International Nuclear Information System (INIS)

    Aung, Thet; Baik, Diane

    2014-01-01

    were seen in the underweight and wasting levels. However, significant improvements in the median height-for-age z-score (HAZ) were found in levels of stunting on Day-1 (-2.37 SD, n = 381) vs. 6-month follow-up (-1.99 SD, n = 314)(Z = -7.683, p<0.0001). Unfortunately, there were significant increases in the levels of stunting on Day-1 (-2.37 SD, n = 381) vs. 1-Year follow-up (-2.70 SD, n = 242)(Z = -2.21, p = 0.027). CONCLUSION: An integrated blanket supplementary feeding program could possibly reduce levels of stunting in just 6-months, but continued monitoring is required of the children even if the children are discharged from the program to ensure their rehabilitation is sustained at home. The increase in levels of stunting at 1-Year follow-up may have been due to the fact that many of the rehabilitated children were discharged and not followed up for the study. Thus, further research is needed to assess the effects of integrated blanket supplementary feeding programs on reducing levels of stunting. (author)

  9. Remote handling demonstration of ITER blanket module replacement

    International Nuclear Information System (INIS)

    Kakudate, S.; Nakahira, M.; Oka, K.; Taguchi, K.; Obara, K.; Tada, E.; Shibanuma, K.; Tesini, A.; Haange, R.; Maisonnier, D.

    2001-01-01

    In ITER, the in-vessel components such as blanket are to be maintained or replaced remotely since they will be activated by 14 MeV neutrons, and a complete exchange of shielding blanket with breeding blanket is foreseen after the Basic Performance Phase. The blanket is segmented into about seven hundred modules to facilitate remote maintainability and allow individual module replacement. For this, the remote handing equipment for blanket maintenance is required to handle a module with a dead weight of about 4 tonne within a positioning accuracy of a few mm under intense gamma radiation. According to the ITER R and D program, a rail-mounted vehicle manipulator system was developed and the basic feasibility of this system was verified through prototype testing. Following this, development of full-scale remote handling equipment has been conducted as one of the ITER Seven R and D Projects aiming at a remote handling demonstration of the ITER blanket. As a result, the Blanket Test Platform (BTP) composed of the full-scale remote handling equipment has been completed and the first integrated performance test in March 1998 has shown that the fabricate remote handling equipment satisfies the main requirements of ITER blanket maintenance. (author)

  10. An assessment of the base blanket for ITER

    International Nuclear Information System (INIS)

    Raffray, A.R.; Abdou, M.A.; Ying, A.

    1991-01-01

    Ideally, the ITER base blanket would provide the necessary tritium for the reactor to be self-sufficient during operation, while having minimal impact on the overall reactor cost, reliability and safety. A solid breeder blanket has been developed in CDA phase in an attempt to achieve such objectives. The reference solid breeder base blanket configurations at the end of the CDA phase has many attractive features such as a tritium breeding ratio (TBR) of 0.8--0.9 and a reasonably low tritium inventory. However, some concerns regarding the risk, cost and benefit of the base blanket have been raised. These include uncertainties associated with the solid breeder thermal control and the potentially high cost of the amount of Be used to achieve high TBR and to provide the necessary thermal barrier between the high temperature solid breeder and low temperature coolant. This work addresses these concerns. The basis for the selection of a breeding blanket is first discussed in light of the incremental risk, cost and benefits relative to a non-breeding blanket. Key issues associated with the CDA breeding blanket configurations are then analyzed. Finally, alternative schemes that could enhance the attractiveness and flexibility of a breeding blanket are explored

  11. Design analyses of self-cooled liquid metal blankets

    International Nuclear Information System (INIS)

    Gohar, Y.

    1986-12-01

    A trade-off study of liquid metal self-cooled blankets was carried out to define the performance of these blankets and to determine the potential to operate at the maximum possible values of the performance parameters. The main parameters considered during the course of the study were the tritium breeding ratio (TBR), the blanket energy multiplication factor, the energy fraction lost to the shield, the lithium-6 enrichment in the breeder material, the total blanket thickness, the reflector material selection, and the compositions of the different blanket zones. Also, a study was carried out to assess the impact of different reactor design choices on the reactor performance parameters. The design choices include the impurity control system (limiter or divertor), the material choice for the limiter, the elimination of tritium breeding from the inboard section of tokamak reactors, and the coolant choice for the nonbreeding inboard blanket. In addition, tritium breeding benchmark calculations were performed using different transport codes and nuclear data libraries. The importance of the TBR in the blanket design motivated the benchmark calculations

  12. Preliminary study on lithium-salt aqueous solution blanket

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Naruse, Yuji; Yamaoka, Mitsuaki; Ohara, Atsushi; Ono, Kiyoshi; Kobayashi, Shigetada.

    1992-06-01

    Aqueous solution blanket using lithium salts such as LiNO 3 and LiOH have been studied in the US-TIBER program and ITER conceptual design activity. In the JAERI/LANL collaboration program for the joint operation of TSTA (Tritium Systems Test Assembly), preliminary design work of blanket tritium system for lithium ceramic blanket, aqueous solution blanket and liquid metal blanket, have been performed to investigate technical feasibility of tritium demonstration tests using the TSTA. Detail study of the aqueous solution blanket concept have not been performed in the Japanese fusion program, so that this study was carried out to investigate features of its concept and to evaluated its technical problems. The following are the major items studied in the present work: (i) Neutronics of tritium breeding ratio and shielding performance Lithium concentration, Li-60 enrichment, beryllium or lead, composition of structural material/beryllium/solution, heavy water, different lithium-salts (ii) Physicochemical properties of salts Solubility, corrosion characteristics and compatibility with structural materials, radiolysis (iii) Estimation of radiolysis in ITER aqueous solution blanket. (author)

  13. Growth of lowland broccoli coconut coir dust and peat based growing media using fertigation system

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Asiah; Abdul Rahman, Shyful Azizi; Nordin, Latiffah; Abdullah, Hazlina; Ruslan, Abdul Razak [Malaysian Inst. for Nuclear Technology Research MINT, Bangi (Malaysia). Agrotechnology and Bioscineces Div.; Taib, Mohd Idris [Malaysian Inst. for Nuclear Technology Research MINT, Bangi (Malaysia). Intelligent Group

    2004-07-01

    A study was carried out inside the greenhouse to determine the response of lowland broccoli (Brassica oleracea) plants grown in five mixtures of coconut coir dust and peat as the growing media. The growing mixes were prepared in the following ratios (% by vol): 100% coconut coir dust, 75% coconut coir dust + 25% peat, 50% coconut coir dust + 50% peat, 25% coconut coir dust + 75% peat and 100% peat. The plants were supplied with 200 mg 1-1 nitrogen using a computerized fertigation system developed at MINT Plants grown on 100% peat exhibited reduced plant growth and yield compared to plants grown on mixes containing coconut coir dust. Plants growth and yield were increased on growing media contained > 50% coconut coir dust; however, the highest total plant dry weight, plant height and yield were obtained from plants grown on 100% coconut coir dust. Total nitrogen concentration in the leaves and stems was not significantly different in all mixture of the growing media regardless of whether coconut coir dust or peat was used. In general, nitrate -nitrogen concentrations were lowest in the floret than in the leaves and stem tissues of plants grown on all growing media used in the study. However, nitrate-nitrogen concentrations in the leaves, stems and florets were lowest in the plants grown on 100% peat compared to the plants grown on growing media containing coconut coir dust. The concentrations of nitrate-nitrogen in the florets, which ranged from 290 to 450 mg N kg-l/dry weight, are considered to be under permissible levels by European standards. (Author)

  14. Growth of lowland broccoli coconut coir dust and peat based growing media using fertigation system

    International Nuclear Information System (INIS)

    Asiah Ahmad; Shyful Azizi Abdul Rahman; Latiffah Nordin; Hazlina Abdullah; Abdul Razak Ruslan; Mohd Idris Taib

    2004-01-01

    A study was carried out inside the greenhouse to determine the response of lowland broccoli (Brassica oleracea) plants grown in five mixtures of coconut coir dust and peat as the growing media. The growing mixes were prepared in the following ratios (% by vol): 100% coconut coir dust, 75% coconut coir dust + 25% peat, 50% coconut coir dust + 50% peat, 25% coconut coir dust + 75% peat and 100% peat. The plants were supplied with 200 mg 1-1 nitrogen using a computerized fertigation system developed at MINT Plants grown on 100% peat exhibited reduced plant growth and yield compared to plants grown on mixes containing coconut coir dust. Plants growth and yield were increased on growing media contained > 50% coconut coir dust; however, the highest total plant dry weight, plant height and yield were obtained from plants grown on 100% coconut coir dust. Total nitrogen concentration in the leaves and stems was not significantly different in all mixture of the growing media regardless of whether coconut coir dust or peat was used. In general, nitrate -nitrogen concentrations were lowest in the floret than in the leaves and stem tissues of plants grown on all growing media used in the study. However, nitrate-nitrogen concentrations in the leaves, stems and florets were lowest in the plants grown on 100% peat compared to the plants grown on growing media containing coconut coir dust. The concentrations of nitrate-nitrogen in the florets, which ranged from 290 to 450 mg N kg-l/dry weight, are considered to be under permissible levels by European standards. (Author)

  15. Nuclear characteristics of D-D fusion reactor blankets

    International Nuclear Information System (INIS)

    Nakashima, Hideki; Ohta, Masao

    1978-01-01

    Fusion reactors operating on deuterium (D-D) cycle are considered to be of long range interest for their freedom from tritium breeding in the blanket. The present paper discusses the various possibilities of D-D fusion reactor blanket designs mainly from the standpoint of the nuclear characteristics. Neutronic and photonic calculations are based on presently available data to provide a basis of the optimal blanket design in D-D fusion reactors. It is found that it appears desirable to design a blanket with blanket/shield (BS) concept in D-D fusion reactors. The BS concept is designed to obtain reasonable shielding characteristics for superconducting magnet (SCM) by using shielding materials in the compact blanket. This concept will open the possibility of compact radiation shield design based on assured technology, and offer the advantage from the system economics point of view. (auth.)

  16. Some peat deposits in Penobscot County, Maine

    Science.gov (United States)

    Cameron, Cornelia Clermont; Anderson, Walter A.

    1979-01-01

    Twenty of the peat deposits in Penobscot County, Maine contain an estimated 29,282,000 short tons air-dried peat. The peat is chiefly sphagnum moss and reed-sedge of high quality according to ASTM standards for agricultural and horticultural use. Analyses show that this same volume has high fuel value, low sulfur and high hydrogen contents compared with lignite and sub-bituminous coal, which may indicate that it also has potential for fuel use. On the basis of the metallic trace element content, one area within the region containing the 20 deposits has been delineated for further bedrock studies.

  17. Peat resource estimation in South Carolina. Final report, Year 2

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, M.; Andrejko, M.; Corvinus, D.; Tisdale, M.

    1982-01-01

    South Carolina has few indigenous energy resources. Most widely known and utilized are hydropower, wood, and solar. Peat is a material composed of partially decomposed organic matter that, after burial for long periods of time, may eventually become coal. Peat is utilized as an energy resource for the production of electricity and for home heating in Europe and the Soviet Union. There are peat deposits in South Carolina, but peat has never been used as an energy resource within the state. This report presents the results of the two years of a planned four-year study of the quantity and energy potential of peat in South Carolina. In this year's survey two activities were undertaken. The first was to visit highly probable peat deposits to confirm the presence of fuel-grade peat. The second was to survey and characterize in more detail the areas judged to be of highest potential as major resources. The factors carrying the greatest weight in our determination of priority areas were: (1) a description of peat deposits in the scientific literature or from discussions with state and federal soil scientists; (2) mention of organic soils on soil maps or in the literature; and (3) information from farmers and other local citizens.

  18. Peat swamp forest of Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Niyomdham, C.; Urapeepatanapong, C.; Pitayakajornwute, P. [Pikoolthong Royal Development Study Center, Bangkok (Thailand). Royal Forest Department

    1996-12-31

    Peat swamp forest in Thailand occurs extensively along coastal flatlands in the central and southern parts of the country and some small patches of topogenous peatland are present locally on several mountain tops of the northern region. Many have been deteriorated by recent extensive development programs. However, one large area, about 347.04 km{sup 2}, of ombrogenous peatland is still left intact in the Pru Toh Dang area where conservation activities are being strictly enforced under one of the Royal Initiative Projects. Pru Toh Dang peat consists of 5 metres of fibrous organic soil overlying pyritic marine clay. Despite an inhospitable, submerged and unstable forest floor, the floristic composition of the peat swamp forest is extremely complicated, consisting of 124 families and 470 species of which 109 families and 437 species of flowering plants, and 15 families and 33 species of ferns recorded between 1983-1989 by a team from the Forest Herbarium of the Royal Forest Department of Thailand. (orig.) (4 refs.)

  19. Assessing the Impact of Land Management on Organic Matter Composition in Peat Soils

    Science.gov (United States)

    Savage, A.; Holden, J.; Wainwright, J.

    2010-05-01

    Peatlands are seen as important stores of terrestrial carbon, accounting for up to one-third of global soil carbon stocks. In some cases peatlands are shown to be emitters of carbon, in other cases carbon sinks depending on the site conditions and nature of degradation. However, carbon budget calculations carried out to date have a number of uncertainties associated with them and the composition of the carbon is generally not considered when determining carbon budgets. Carbon cycling in peat is driven by four key factors (Laiho, 2006):, environmental conditions (e.g. temperature, water table level), substrate quality (e.g. how recalcitrant the peat is), nutrients (e.g. nitrogen required to synthesis the carbon stocks) and microbial community (e.g. are the microbes present able to utilise the available substrate). Land management is also recognised as an additional driver, but the impacts of many types of management are poorly understood. Among the four drivers listed by Laiho (2006) substrate quality is seen as the most significant. To date, little work has been carried out to characterise the quality of organic matter in peat soils; rather crude estimates have been made as to the quantity of carbon that is stored in peatlands, yet without understanding the composition of the peat, limitations are imposed on calculations of rates of carbon loss from peatlands. This work seeks to examine how variations in the chemical composition of organic matter in peat varies with land use. The method published by Wieder and Starr (1998) was followed to determine eight fractions: soluble fats and waxes, hot water soluble, hollocellulose, cellulose, soluble phenolics, acid insoluble carbohydrates, water soluble carbohydrates and lignin. Samples were taken from burnt, grazed, drained, afforested and undisturbed sites at the Moor House UNESCO Biosphere Reserve in Northern England. The method was used to identify if differences were present in the recalcitrance of the peat and linked

  20. Benchmark calculations for fusion blanket development

    International Nuclear Information System (INIS)

    Sawan, M.L.; Cheng, E.T.

    1986-01-01

    Benchmark problems representing the leading fusion blanket concepts are presented. Benchmark calculations for self-cooled Li 17 Pb 83 and helium-cooled blankets were performed. Multigroup data libraries generated from ENDF/B-IV and V files using the NJOY and AMPX processing codes with different weighting functions were used. The sensitivity of the tritium breeding ratio to group structure and weighting spectrum increases as the thickness and Li enrichment decrease with up to 20% discrepancies for thin natural Li 17 Pb 83 blankets. (author)

  1. Breeding blankets for thermonuclear reactors

    International Nuclear Information System (INIS)

    Rocaboy, Alain.

    1982-06-01

    Materials with structures suitable for this purpose are studied. A bibliographic review of the main solid and liquid lithiated compounds is then presented. Erosion, dimensioning and maintenance problems associated with the limiter and the first wall of the reactor are studied from the point of view of the constraints they impose on the design of the blankets. Detailed studies of the main solid and liquid blanket concepts enable the best technological compromises to be determined for the indispensable functions of the blanket to be assured under acceptable conditions. Our analysis leads to four classes of solution, which cannot at this stage be considered as final recommendations, but which indicate what sort of solutions it is worthwhile exploring and comparing in order to be in a position to suggest a realistic blanket at the time when plasma control is sufficiently good for power reactors to be envisaged. Some considerations on the general architecture of the reactor are indicated. Energy storage with pulsed reactors is discussed in the appendix, and a first approach made to minimizing the total tritium recovery [fr

  2. Active Pore Volume in Danish Peat Soils

    DEFF Research Database (Denmark)

    Forsmann, Ditte M.; Kjærgaard, Charlotte

    2012-01-01

    Phosphorus release within the soil matrix caused by the changed redox conditions due to re-establishment of a riparian wetland can be critical for the aquatic environment. However, phosphorous released in the soil will not always result in an immediate contribution to this loss to the aquatic...... environment. Lowland soils are primarily peat soils, and only a minor part of the total soil volume of peat soils is occupied by macropores (>30 µm). Since water primarily flows in these macropores, the majority of the soil matrix is bypassed (the immobile domain). Phosphorus released in the immobile domain...... is not actively transported out of the system, but is only transported via diffusion, which is a very slow process. Thus it is interesting to investigate the size of the active pore volume in peat soils. The hypothesis of this study is that the active pores volume of a peat soil can be expressed using bulk...

  3. Acceleration of peat drying by intensifying the heat and mass transfer; Turpeen kuivumisen nopeuttaminen laemmoen- ja aineensiirtoa tehostamalla

    Energy Technology Data Exchange (ETDEWEB)

    Hillebrand, K.

    1996-12-31

    The efficiency of peat production can be increased by intensifying peat drying. To intensify drying one has to know the effects of the different factors affecting the heat and mass transfer in the drying layer and in the soil. The objective of the study is to increase the degree of utilization of solar energy in drying of peat from the present level of 30% to 40% of the total incoming solar energy. In this way it is possible to reduce the peat production costs about 10%. A numerical drying model has been developed which describes the transfer of liquid water, water vapor and heat in the drying layer and in the soil. In addition, the interaction between the atmosphere and the drying layer, as well as the rainfall interception by the layer, infiltration, evaporation, and drainage have been taking into account. Daily input requirements include global solar radiation, air temperature and relative humidity, wind speed and precipitation. In addition to the weather data one has to know the characteristics of the drying layer and the soil. The numerical drying model was also used to study the effect of soil frost on peat drying and the possibilities to hinder the frost formation. Producing peat on the field which is still partly frozen, the drying of peat takes 10 - 25% longer time than under normal conditions, which means 5 - 25 hours longer drying period. By forming a porous, insulating layer on the top of the soil surface, one can hinder the frost formation significantly. Raising the groundwater level prevents, however, only a little the frost formation in peat soil

  4. Tritium inventory and permeation in liquid breeder blankets

    International Nuclear Information System (INIS)

    Reiter, F.

    1990-01-01

    This report reviews studies of the transport of hydrogen isotopes in the DEMO relevant water-cooled Pb-17Li blanket to be tested in NET and in a self-cooled blanket which uses Pb-17Li or Flibe as a liquid breeder material and V or Fe as a first wall material. The time dependences of tritium inventory and permeation in these blankets and of deuterium and tritium recycling in the self-cooled blanket are presented and discussed

  5. Peat development in Newfoundland: an historic overview. [Canada - Newfoundland

    Energy Technology Data Exchange (ETDEWEB)

    Rayment, A.F. (Newfoundland and Labrador Peat Association, St. John' s, NF (Canada))

    1994-02-01

    The aboriginal people and early white settlers doubtless had many uses for peat, although we have few specifics. A concerted effort was made in the 1930s to drain and develop certain peat bogs for growing forages, but interest in the agricultural use of peat waned during World War II and did not return until after Confederation in 1949. The Royal Commission Report on Agriculture (1956) recommended investigation of the feasibility of peat moss for agricultural purposes. From this point, research was conducted chiefly by the federal Experimental Farm near St. John's and by the provincial government, with some input from Memorial University. All peat moss developments must be preceded by drainage, which in turn should be preceded by a contour and depth survey. Mechanical aspects for drainage have evolved considerably. About 1,300 acres were drained by the Cuthbertson plow up to 1960 and another 2500 acres drained by the Healy ditcher between then and 1967; no subsequent reports have been obtained. Research has been conducted into fertilizer requirements for forages. Experiments on the grazing of sheep and/or cattle were also conducted and some problems were encountered, particularly with the grazing of sheep. Also studied was the potential of peat moss production for poultry litter, and the use of peat, kelp and fish offal to produce a high value compost. 28 refs.

  6. OSPW contamination transport through peat soils : laboratory and greenhouse study

    Energy Technology Data Exchange (ETDEWEB)

    Rezanezhad, F.; Price, J.S. [Waterloo Univ., ON (Canada). Dept. of Geography; Rochefort, L.; Pouliot, R. [Laval Univ., Quebec City, PQ (Canada). Dept. of Phytology; Andersen, R. [Laval Univ., Quebec City, PQ (Canada). Dept. of Phytology; Macaulay Land Use Research Inst., Aberdeen (United Kingdom); Daly, C. [Suncor Energy, Fort McMurray, AB (Canada)

    2010-07-01

    Large portions of northern Canada are covered by peatlands, and the majority of post-mined landscapes have increased salinity, heavy metals and naphthenic acids (NA). This PowerPoint presentation discussed laboratory and greenhouse studies conducted to determine oil sands process water (OSPW) contamination transport through peat soils. Peat is a highly complex porous media. The presence of sodium and NA has a toxic effect on aquatic life. Greenhouse studies were conducted to determine the changes caused by OSPW in the microbial community of a peat matrix over 2 growing seasons. The study showed that peat has an exceptional ability to absorb the contaminants in OSPW water. NA and sodium transport through peat was significantly delayed by sorption, and by diffusion into immobile water contained in the peat matrix. The vegetation in the study was healthy and tolerant to the contaminants in the OSPW. tabs., figs.

  7. Objectives and status of EUROfusion DEMO blanket studies

    Energy Technology Data Exchange (ETDEWEB)

    Boccaccini, L.V., E-mail: lorenzo.boccaccini@kit.edu [Karlsruhe Institute of Technology (KIT) (Germany); Aiello, G.; Aubert, J. [CEA-Saclay, DEN, DM2S, SEMT, F-91191 Gif-sur-Yvette (France); Bachmann, C. [EUROfusion, PPPT, Garching (Germany); Barrett, T. [CCFE, Abingdon OX14 3DB (United Kingdom); Del Nevo, A. [ENEA CR Brasimone, 40032 Camugnano, BO (Italy); Demange, D. [Karlsruhe Institute of Technology (KIT) (Germany); Forest, L. [CEA-Saclay, DEN, DM2S, SEMT, F-91191 Gif-sur-Yvette (France); Hernandez, F.; Norajitra, P. [Karlsruhe Institute of Technology (KIT) (Germany); Porempovic, G. [Fuziotech Engineering Ltd (Hungary); Rapisarda, D. [CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Sardain, P. [CEA/IRFM, 13115 Saint-Paul-lès-Durance (France); Utili, M. [ENEA CR Brasimone, 40032 Camugnano, BO (Italy); Vala, L. [Centrum výzkumu Řež, 250 68 Husinec-Řež (Czech Republic)

    2016-11-01

    Highlights: • Short description of the new Breeding Blanket Project in the EUROfusion consortium for the design of the EU PPPT DEMO: objectives. • Presentation of the design approach used in the development of the Breeding Blanket design: requirements. • Breeding Blanket design; in particular the four blanket concepts included in the study are presented, recent results highlighted and the status discussed. • Auxiliary systems and related R&D programme: in particular the work areas addressed in the Project (Tritium Technology, Pb-Li and Solid Breeders Technology, First Wall Design and R&D, Manufacturing) are presented, recent results highlighted and the status discussed. - Abstract: The design of a DEMO reactor requires the design of a blanket system suitable of reliable T production and heat extraction for electricity production. In the frame of the EUROfusion Consortium activities, the Breeding Blanket Project has been constituted in 2014 with the goal to develop concepts of Breeding Blankets for the EU PPPT DEMO; this includes an integrated design and R&D programme with the goal to select after 2020 concepts on fusion plants for the engineering phase. The design activities are presently focalized around a pool of solid and liquid breeder blanket with helium, water and PbLi cooling. Development of tritium extraction and control technology, as well manufacturing and development of solid and PbLi breeders are part of the programme.

  8. Carbon dioxide emission from raised bog surface after peat extraction

    Directory of Open Access Journals (Sweden)

    Turbiak Janusz

    2017-12-01

    Full Text Available Research on CO2 emission from a raised bog after completion of peat extraction was performed in 2011–2013. CO2 emissions were determined by the chamber method. Twenty years after the termination of peat extraction, the bog surface was almost entirely devoid of plants. CO2 emission from the bog varied depending on temperature and water conditions and was 418 mg·m−2·h−1 on average during the research period. CO2 losses on the raised bog were on average 19.7 Mg·ha−1·year−1 during the research period which corresponded to a carbon loss of 5.37 Mg·ha−1·year−1 or mineralisation of 9.6 Mg·ha−1·year−1 of organic mass of 56% carbon content. It is possible to reduce organic mass losses and CO2 emission to the atmosphere from the bog surface after peat extraction has been terminated by reconstruction of initial water conditions, i.e. retaining a high ground water level and restoration of aquatic plant communities.

  9. Radiocarbon dating of Sphagnum cellulose from Mohos peat bog, East Carpathians

    Science.gov (United States)

    Hubay, Katalin; Braun, Mihály; Harangi, Sándor; Palcsu, László; Túri, Marianna; Rinyu, László; Molnár, Mihály

    2015-04-01

    This work focuses on building a high-resolution age-depth model for quantitative paleoclimate study from the Mohos peat bog, East Carpathians. Peats are important archives for Quaternary science, because they preserve environmental changes. To study the chronology of peat profiles the key is in the precise coring and reliable dating. However, many studies dealing with coring and radiocarbon dating of peat deposits they often shown problems with the proper methods and material. With our novel coring technique we reached undisturbed and uncompressed peat cores from the Mohos bog. A 10 meter deep peat profile was drilled in 2012 using a modified technique of a piston corer. The core presents a continuous peat profile from the last 11.500 cal. yr BP. The chronology was based on AMS radiocarbon analyses of the separated Sphagnum samples from different depths of the profile. The peat samples were wet sieved (40-280 μm) to avoid contamination by rootlets. Dry Sphagnum samples for AMS dating were prepared using the classical acid-base-acid (ABA) method completed with an oxidative bleaching step to get clean cellulose. Sphagnum cellulose samples were converted to CO2 and later graphite and measured by EnvironMICADAS accelerator mass spectrometry (AMS) in Hertelendi Laboratory (Debrecen, Hungary). Fine peat accumulation rate changes (sections with lowest accumulation values) were observed along the profile. Based on the chronology in further studies we want to focus special intervals to investigate environmental changes in the Holocene. Key words: peat, radiocarbon, cellulose

  10. AQUAPEAT 95. New methods for purifying the run-offs of peat production areas

    International Nuclear Information System (INIS)

    Selin, P.; Marja-aho, J.; Madekivi, O.

    1994-01-01

    The aim of Aqua Peat 95-project was to develop new methods for purifying the runoff coming from the peat production areas. The national water protection program for the year 1995 (Ympaeristoeministerioe 1988) as well as the level of the requirements and instructions from the authorities will obligate the peat producers to find new and practical methods for water purification. The chemical treatment reduced the load of peat production areas and the quality of treated water was almost equal to the runoffs coming from the natural bog area. The chemicals were the same as used in purifying drinking water. This purifying method is quite expensive and for this reason applicable only in special cases. The transpiration and evaporation and the soil filtering capacity of the forest area was also observed. The purifying capacity was very good, especially for the total nutrients and suspended solids. The changes of the ground water quality were insignificant but the level of the ground water in the field areas was higher than before. The long term changes of the vegetation and the trees could not be seen, yet. The most important water management practice is the detention of the discharge. The capacity of the sedimentation will increase by using the flow regulation in the sedimentation ponds and ditches. The changes in the water biology downstreams the Laeynioensuo peat production area were clearly seen near the main ditch. Because of the suspended solids the bottom sediment changed which lead to impacts to the bottom fauna. The colour of the runoffs as well as the changes in the sediment influenced on the macrophytes

  11. Mangrove peat analysis and reconstruction of vegetation history at the Pelican Cays, Belize

    Science.gov (United States)

    McKee, K.L.; Faulkner, P.L.

    2000-01-01

    The substrate beneath mangrove forests in the Pelican Cays complex is predominately peat composed mainly of mangrove roots. Leaves and wood account for less than 20% of the peat mass. At Cat Cay, the depth of the peat ranges from 0.2 m along the shoreline to 1.65 m in the island center, indicating that the island has expanded horizontally as well as vertically through below-ground, biogenic processes. Mangrove roots thus play a critical role in the soil formation, vertical accretion, and stability of these mangrove cays. The species composition of fossil roots changes markedly with depth: Rhizophora mangle (red mangrove) was the initial colonizer on a coral base, followed by Avicennia germinans (black mangrove), which increased in abundance and expanded radially from the center of the island. The center of the Avicennia stand ultimately died, leaving an unvegetated, shallow pond. The peat thus retains a record of mangrove development, succession, and deterioration in response to sea-level change and concomitant hydroedaphic conditions controlling dispersal, establishment, growth, and mortality of mangroves on oceanic islands in Belize.

  12. Thermal comfort and safety of cotton blankets warmed at 130°F and 200°F.

    Science.gov (United States)

    Kelly, Patricia A; Cooper, Susan K; Krogh, Mary L; Morse, Elizabeth C; Crandall, Craig G; Winslow, Elizabeth H; Balluck, Julie P

    2013-12-01

    In 2009, the ECRI Institute recommended warming cotton blankets in cabinets set at 130°F or less. However, there is limited research to support the use of this cabinet temperature. To measure skin temperatures and thermal comfort in healthy volunteers before and after application of blankets warmed in cabinets set at 130 and 200°F, respectively, and to determine the time-dependent cooling of cotton blankets after removal from warming cabinets set at the two temperatures. Prospective, comparative, descriptive. Participants (n = 20) received one or two blankets warmed in 130 or 200°F cabinets. First, skin temperatures were measured, and thermal comfort reports were obtained at fixed timed intervals. Second, blanket temperatures (n = 10) were measured at fixed intervals after removal from the cabinets. No skin temperatures approached levels reported in the literature that cause epidermal damage. Thermal comfort reports supported using blankets from the 200°F cabinet, and blankets lost heat quickly over time. We recommend warming cotton blankets in cabinets set at 200°F or less to improve thermal comfort without compromising patient safety. Copyright © 2013 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

  13. Decadal changes in peat carbon accrual rates in bogs in Northern Minnesota

    Science.gov (United States)

    Fissore, C.; Nater, E. A.; McFarlane, K. J.

    2017-12-01

    Throughout the Holocene, peatland ecosystems have accumulated substantial amounts of carbon (C) and currently store about one third of all soil organic carbon (SOC) worldwide. Large uncertainty still persists on whether peatland ecosystems located in northern latitudes will continue to act as C sinks, or if the effects of global warming will have greater effects on decomposition processes than on net ecosystem production. We investigated decadal C accrual rates of the top 25 cm of peats in three Sphagnum-rich peatlands located in Northern Minnesota (two ombrotrophic bogs and one fen). We used radiocarbon analysis of Sphagnum cellulose and model fitting to determine peat ages, and peat FTIR spectroscopy to determine humification indices and relative decomposition of peat samples with depth. We had the scope to detect whether recent warming has had an effect on peat decomposition and C accumulation rates. Modeled C accumulation rates in the three peatlands during the past five decades ranged between 78 and 107 g C m-2 yr-1 in the top 25 cm analyzed in this study, values that are higher than the 22 to 29 g C m-2 yr-1 obtained for long-term (millennial) accumulations for the entire bog profiles. Peat IR spectra and C:N ratios confirm low levels of decomposition across the bog sites, especially in the uppermost parts of the peat. The fen site showed very limited decomposition across the entire sampled profile. Higher rates of C accumulation, combined with low decomposition rates close to the surface provide a good estimate of net primary productivity. As substrate decomposition progresses over time, net rates of accumulation decrease. Peat decomposition was more pronounced in the lower depths of the sampled cores in the two ombrotrophic bogs than in the fen, likely an effect of larger temporal variation in water table depth in the bogs than in the fen. Some of the variation in C accumulation and decomposition observed in our bogs and fen suggests that future C

  14. Design and development of ceramic breeder demo blanket

    International Nuclear Information System (INIS)

    Enoeda, M.; Sato, S.; Hatano, T.

    2001-01-01

    Ceramic breeder blanket development has been widely conducted in Japan from fundamental researches to project-oriented engineering scaled development. A long term R and D program has been launched in JAERI since 1996 as a course of DEMO blanket development. The objectives of this program are to provide engineering data base and fabrication technologies of the DEMO blanket, aiming at module testing in ITER currently scheduled to start from the beginning of the ITER operation as a near-term target. Two types of DEMO blanket systems, water cooled blanket and helium cooled blanket, have been designed to be consistent with the SSTR (Steady State Tokamak Reactor) which is the reference DEMO reactor design in JAERI. Both of them utilize packed small pebbles of breeder Li 2 O or Li 2 TiO 3 as a candidate) and neutron multiplier (Be) and rely on the development of advanced structural materials (a reduced activation ferritic steel F82H) compatible with high temperature operation. (author)

  15. Conceptual design of Blanket Remote Handling System for CFETR

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Jianghua, E-mail: weijh@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Song, Yuntao, E-mail: songyt@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); University of Science and Technology of China, Hefei (China); Pei, Kun; Zhao, Wenlong; Zhang, Yu; Cheng, Yong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China)

    2015-11-15

    Highlights: • The concept for the blanket maintenance is carried out, including three sub-systems. • The basic maintenance procedure for blanket between VV and hot cell is carried out. • The primary kinematics study is used to verify the feasibility of BRHS. • Virtual reality is adopted as another approach to verify the concept design. - Abstract: The China Fusion Engineering Testing Reactor (CFETR), which is a new superconducting tokamak device being designed by China, has a mission to achieve a high duty time (0.3–0.5). To accomplish this great mission, the big modular blanket option has been adopted to achieve the high efficiency of the blanket maintenance. Considering this mission and the large and heavy blanket module, a novel conceptual blanket maintenance system for CFETR has been carried out by us over the past year. This paper presents the conceptual design of the Blanket Remote Handling System (BRHS), which mainly comprises the In-Vessel-Maintenance-System (IVMS), Lifting System and Blanket-Tool-Manipulator System (BTMS). The BRHS implements the extraction and replacement between in-vessel (the blanket module operation configuration location) and ex-vessel (inside of the vertical maintenance cask) by the collaboration of these three sub systems. What is more, this paper represents the blanket maintenance procedure between the docking station (between hot cell building and tokamak building) and inside the vacuum vessel, in tokamak building. Virtual reality technology is also used to verify and optimize our concept design.

  16. Conceptual design of Blanket Remote Handling System for CFETR

    International Nuclear Information System (INIS)

    Wei, Jianghua; Song, Yuntao; Pei, Kun; Zhao, Wenlong; Zhang, Yu; Cheng, Yong

    2015-01-01

    Highlights: • The concept for the blanket maintenance is carried out, including three sub-systems. • The basic maintenance procedure for blanket between VV and hot cell is carried out. • The primary kinematics study is used to verify the feasibility of BRHS. • Virtual reality is adopted as another approach to verify the concept design. - Abstract: The China Fusion Engineering Testing Reactor (CFETR), which is a new superconducting tokamak device being designed by China, has a mission to achieve a high duty time (0.3–0.5). To accomplish this great mission, the big modular blanket option has been adopted to achieve the high efficiency of the blanket maintenance. Considering this mission and the large and heavy blanket module, a novel conceptual blanket maintenance system for CFETR has been carried out by us over the past year. This paper presents the conceptual design of the Blanket Remote Handling System (BRHS), which mainly comprises the In-Vessel-Maintenance-System (IVMS), Lifting System and Blanket-Tool-Manipulator System (BTMS). The BRHS implements the extraction and replacement between in-vessel (the blanket module operation configuration location) and ex-vessel (inside of the vertical maintenance cask) by the collaboration of these three sub systems. What is more, this paper represents the blanket maintenance procedure between the docking station (between hot cell building and tokamak building) and inside the vacuum vessel, in tokamak building. Virtual reality technology is also used to verify and optimize our concept design.

  17. Economic evaluation of the Blanket Comparison and Selection Study

    International Nuclear Information System (INIS)

    Waganer, L.M.

    1985-01-01

    The economic impact of employing the highly ranked blankets in the Blanket Comparison and Selection Study (BCSS) was evaluated in the context of both a tokamak and a tandem mirror power reactor (TMR). The economic evaluation criterion was determined to be the cost of electricity. The influencing factors that were considered are the direct cost of the blankets and related systems; the annual cost of blanket replacement; and the performance of the blanket, heat transfer, and energy conversion systems. The technical and cost bases for comparison were those of the STARFIRE and Mirror Advanced Reactor Study conceptual design power plants. The economic evaluation results indicated that the nitrate-salt-cooled blanket concept is an economically attractive concept for either reactor type. The water-cooled, solid breeder blanket is attractive for the tokamak and somewhat less attractive for the TMR. The helium-cooled, liquidlithium breeder blanket is the least economically desirable of higher ranked concepts. The remaining self-cooled liquid-metal and the helium-cooled blanket concepts represent moderately attractive concepts from an economic standpoint. These results are not in concert with those found in the other BCSS evaluation areas (engineering feasibility, safety, and research and development (R and D) requirements). The blankets faring well economically had generally lower cost components, lower pumping power requirements, and good power production capability. On the other hand, helium- and lithium-cooled systems were preferred from the standpoints of safety, engineering feasibility, and R and D requirements

  18. Developing of milled peat production control in Turveruukki Oy

    Energy Technology Data Exchange (ETDEWEB)

    Ljokkoi, R

    1985-01-01

    Control research on the production of milled peat has as its primary aim the ability to control the peat drying process under different weather and field conditions. Actual development work connected with production control was begun in 1982 with the clear aim of developing and applying in practice a monitoring adn control system complete with measuring equipment which would permit the drying process to be measured indirectly and weather forecasts to be used systematically in the planning of production at each individual peat site. During the 1984 production season development work reached the stage of experimental use. Experiences gained from trial use have been mainly positive and trial use of the manual system can be considered the first step in the application o the system. As regards the measuring technique, it is justified to say that an adequate technical level has already been attained and the correlation of the indirect measuring method with peat drying can be further improved by adjusting the location height of the evaporation meter. On the other hand, calculation of the length of the harvesting cycle requires further research, which from the point of view of practice must be orientated towards control of field conditions and changes in them during the production season. Although the application of the production control system is informative in nature, it is clearly of assistance when deciding how to carry out production. By means of this system iy id possible to achieve financial benefit in the form of lowered production costs and a larger harvest per hectare.

  19. Review of pre-treated peat applied in treating domestic wastewaters and oily waters

    International Nuclear Information System (INIS)

    Jiang, X.; Coles, C.A.; Asapo, E.S.

    2008-01-01

    This paper discussed recent research related to the use of peat in removing contaminants from domestic wastewater, oil-contaminated water, and soil. The review also discussed methods of pretreating peat before its application to polluted area. Pretreatment processes are needed to remove components in peat that interfere with treatment mechanisms. Polymers are added to peat in order to encourage the aggregation of the peat particles into larger colloidal particles that are easy to dewater. Phosphoric acid treatments are also applied to increase the swelling capacity of peat. Hydrogen peroxide is used to break down oil-contaminated peat in order to facilitate its subsequent decomposition. Experiments have demonstrated that peat is an effective adsorbent for many different types of oil. Studies have demonstrated that the removal rate for standard mineral and crude oils from wastewater using peat was 83 and 70 per cent. Applications of commercial peat to the surface of oily contaminated waters resulted in oil removal efficiencies of 99.998 per cent. It was concluded that peat is an effective, low-cost material for removing contaminants from domestic waste water and oil-contaminated water. The peat can also be used as a secondary energy source after the sorption process. While peat is an abundant resource in Canada, the resource is found mainly in wetlands. Effective harvesting strategies should be used to ensure the environmental sustainability of peat filtration systems. 38 refs., 1 tab

  20. Fusion blankets for high efficiency power cycles

    International Nuclear Information System (INIS)

    Powell, J.R.; Fillo, J.A.; Horn, F.L.; Lazareth, O.W.; Usher, J.L.

    1980-04-01

    Definitions are given of 10 generic blanket types and the specific blanket chosen to be analyzed in detail from each of the 10 types. Dimensions, compositions, energy depositions and breeding ratios (where applicable) are presented for each of the 10 designs. Ultimately, based largely on neutronics and thermal hyraulics results, breeding an nonbreeding blanket options are selected for further design analysis and integration with a suitable power conversion subsystem

  1. Electromagnetic analysis of ITER shield blanket under VDE

    International Nuclear Information System (INIS)

    Kang Weishan; Chen Jiming; Wu Jihong; Wang Mingxu

    2010-01-01

    Electromagnetic force and torque of ITER shield blanket system and their surrounding major component under vertical displacement event (VDE) were calculated with finite element method. ANSYS APDL was used to simulate the shape and magnitude of plasmas current dynamically in the VDE course, and external magnetic field was imposed, then the induced current distribution inside the all conductor including the blanket was obtained from the calculation. The force and torque for every blanket module was obtained to assess the safety of blanket system under VDE. (authors)

  2. Study of removing a peat-layer from surface active agents; Deitanso ni yoru kaimen kasseizai no jokyo

    Energy Technology Data Exchange (ETDEWEB)

    Umemiya, H; Kitamura, K [Yamagata University, Yamagata (Japan)

    1996-10-27

    An experiment was performed on a system for recycling water resources by using a peat-layer. A laboratory device was also made in order to examine the effects of a peat-layer on surface active agents. In the experiment, a water examination was carried out in which a mixture of water and kitchen detergent at the rate of 15,000 to 1 was filtered through a peat-layer of 2-3cm thick, as was a mixture of water, kitchen detergent and oil at the rate of 15,000 to 1 to 2. In the water examination, various measurements were done such as the measurement of COD by potassium permanganate acid process, measurement of pH by a pH meter with glass electrodes and measurement of coefficient of permeability by a variable water level permeability test. As a result of the experiment, it was revealed that a peat-layer had ability to remove surface active agents, that injection water tended to increase acidity in a peat-layer and that a peat-layer had ability to remove foaming of surface active agents. The COD of domestic waste water decreased from 12mg/l to 0.16mg/l in the system for recycling water resources using a peat-layer. 3 refs., 10 figs., 1 tab.

  3. Neutronic design for the TFTR lithium blanket module

    International Nuclear Information System (INIS)

    Cheng, E.T.; Engholm, B.A.; Su, S.D.

    1981-01-01

    The preliminary design of a lithium blanket module (LBM) to be installed and tested in the TFTR has been performed under subcontract to PPPL and EPRI. The objectives of the LBM program are calculation and measurement of neutron fluences and tritium production in a breeding blanket module using state of art techniques, comparison of calculations with measurements, and acquisition of operational experience with a fusion reactor blanket module. The neutronic design of the LBM is one of the key areas of this program in which the LBM composition and geometry are optimized and the boundary material effects on the tritium production in the blanket module are explored. The concept of employing sintered Li/sub 2/O pellets in tubes is proposed for the blanket design

  4. LMFBR Blanket Physics Project progress report No. 2

    International Nuclear Information System (INIS)

    Forbes, I.A.; Driscoll, M.J.; Rasmussen, N.C.; Lanning, D.D.; Kaplan, I.

    1971-01-01

    This is the second annual report of an experimental program for the investigation of the neutronics of benchmark mock-ups of LMFBR blankets. Work was devoted primarily to measurements on Blanket Mock-Up No. 2, a simulation of a typical large LMFBR radial blanket and its steel reflector. Activation traverses and neutron spectra were measured in the blanket; calculations of activities and spectra were made for comparison with the measured data. The heterogeneous self-shielding effect for 238 U capture was found to be the most important factor affecting the comparison. Optimization and economic studies were made which indicate that the use of a high-albedo reflector material such as BeO or graphite may improve blanket neutronics and economics

  5. Market study on the potential for peat as a fuel

    International Nuclear Information System (INIS)

    1991-01-01

    A report is given on the market potential for peat as a fuel in Scotland. It is concluded that there are two distinct market segments, domestic and industrial/commercial. There is no potential for peat as a fuel in the industrial/commercial segment but there is opportunity for increased peat usage in the domestic sector. The greatest potential for market development is conversion of existing solid fuel users to peat. Pro-active input is required to realise this market potential. The market is constrained by demand. (UK)

  6. Peat is regarded as slowly renewable biomass fuel

    International Nuclear Information System (INIS)

    Myllylae, I.

    2000-01-01

    The Finnish Ministry of Trade and Industry commissioned an investigation on the role of peat in Finnish greenhouse gas balance in 1999. An international scientist group, consisting of Dr. Patrick Crill from USA, Dr. Ken Hargreaves from United Kingdom and docent Atte Korhola from Finland conducted the investigation. The scientist group made the proposition that peat should be classified as a slowly renewable biomass fuel, which is significant from the peat industry's point of view. An interesting detail of the investigation was the calculations, which showed that ditching of peatlands, have decreased the methane emissions from peatlands. Virgin peatlands bind carbon dioxide from the air, but simultaneously they emit methane, which is more harmful than CO 2 emissions. The carbon sink effect of Finnish peatlands is based on the CO 2 binding of virgin and ditched peatlands in Finland. The CO 2 emissions of peat production and combustion are smaller than the CO 2 binding. Virgin peatlands form a relative large source of methane. The investigation shows that when reviewing the effects of all the greenhouse gases on climate, the virgin peatlands may accelerate the greenhouse effect due to the methane emissions. The final conclusion is that ditching of virgin peatlands has reduced the radiation enforcement in Finland in some extent. When a virgin peatland is ditched the methane emissions from it are reduced significantly, and simultaneously more CO 2 is bound into vegetation. According to the investigation the net emissions of greenhouse gases in Finland exceed 10 million tonnes calculated as CO 2 . Of this the share of virgin peatlands is 8.4 million tonnes, which is of the same magnitude as the emissions from peat combustion. The life cycle analysis has shown that peat production should be directed to swampy fields removed from agricultural production. In most of the cases the combination of reforestation and repaludification into a functional peatland ecosystem could

  7. Vesicular-arbuscular mycorrhizal status of plant species in the peat swamp forest of Setia Alam Jaya, Sebangau, Central Kalimantan

    OpenAIRE

    Suciatmih Suciatmih

    2003-01-01

    In order to describe the vesicular-arbuscular mycorrhizal (VAM) status of plants growing on peat soil, a study was carried out inthe peat swamp forest of Setia Alam Jaya in Sebangau, Central Kalimantan. Out of 146 plant root samples belonging to 48 plantspecies from 25 families examined, all plants colonized by VAM fungi namely 14 (29.2%) high level, 32 (66.7%) medium level, and 2(4.1%) low level respectively.

  8. From carbon sink to carbon source: extensive peat oxidation in insular Southeast Asia since 1990

    Science.gov (United States)

    Miettinen, Jukka; Hooijer, Aljosja; Vernimmen, Ronald; Liew, Soo Chin; Page, Susan E.

    2017-02-01

    Tropical peatlands of the western part of insular Southeast Asia have experienced extensive land cover changes since 1990. Typically involving drainage, these land cover changes have resulted in increased peat oxidation in the upper peat profile. In this paper we provide current (2015) and cumulative carbon emissions estimates since 1990 from peat oxidation in Peninsular Malaysia, Sumatra and Borneo, utilizing newly published peatland land cover information and the recently agreed Intergovernmental Panel on Climate Change (IPCC) peat oxidation emission values for tropical peatland areas. Our results highlight the change of one of the Earth’s most efficient long-term carbon sinks to a short-term emission source, with cumulative carbon emissions since 1990 estimated to have been in the order of 2.5 Gt C. Current (2015) levels of emissions are estimated at around 146 Mt C yr-1, with a range of 132-159 Mt C yr-1 depending on the selection of emissions factors for different land cover types. 44% (or 64 Mt C yr-1) of the emissions come from industrial plantations (mainly oil palm and Acacia pulpwood), followed by 34% (49 Mt C yr-1) of emissions from small-holder areas. Thus, altogether 78% of current peat oxidation emissions come from managed land cover types. Although based on the latest information, these estimates may still include considerable, yet currently unquantifiable, uncertainties (e.g. due to uncertainties in the extent of peatlands and drainage networks) which need to be focused on in future research. In comparison, fire induced carbon dioxide emissions over the past ten years for the entire equatorial Southeast Asia region have been estimated to average 122 Mt C yr-1 (www.globalfiredata.org/_index.html). The results emphasise that whilst reducing emissions from peat fires is important, urgent efforts are also needed to mitigate the constantly high level of emissions arising from peat drainage, regardless of fire occurrence.

  9. The climate impact of future energy peat production

    Energy Technology Data Exchange (ETDEWEB)

    Hagberg, Linus; Holmgren, Kristina

    2008-09-15

    The aim of this study was to estimate total greenhouse gas emissions and climate impact of different peat utilisation scenarios, using a life cycle perspective. This and previous studies show that the climate impact from energy peat utilisation is more complex than just considering the emissions at the combustion stage. There are important emissions and uptake of greenhouse gases that occur on the peatland before, during and after peat harvest. The results show that the climate impact of future peat utilisation can be significantly reduced compared to current utilisation and will be lower than the climate impact resulting from only the combustion phase. This can be achieved by choosing already drained peatlands with high greenhouse gas emissions, using a more efficient production method and by securing a low-emission after-treatment of the cutaway (e.g. afforestation)

  10. Liquid metal cooled blanket concept for NET

    International Nuclear Information System (INIS)

    Malang, S.; Casal, V.; Arheidt, K.; Fischer, U.; Link, W.; Rust, K.

    1986-01-01

    A blanket concept for NET using liquid lithium-lead both as breeder material and as coolant is described. The need for inboard breeding is avoided by using beryllium as neutron multiplier in the outboard blanket. Novel flow channel inserts are employed in all poloidal ducts to reduce the MHD pressure drop. The concept offers a simple mechanical design and a higher tritium breeding ratio compared to water- and gas-cooled blankets. (author)

  11. Beryllium R&D for blanket application

    Science.gov (United States)

    Donne, M. Dalle; Longhurst, G. R.; Kawamura, H.; Scaffidi-Argentina, F.

    1998-10-01

    The paper describes the main problems and the R&D for the beryllium to be used as neutron multiplier in blankets. As the four ITER partners propose to use beryllium in the form of pebbles for their DEMO relevant blankets (only the Russians consider the porous beryllium option as an alternative) and the ITER breeding blanket will use beryllium pebbles as well, the paper is mainly based on beryllium pebbles. Also the work on the chemical reactivity of fully dense and porous beryllium in contact with water steam is described, due to the safety importance of this point.

  12. Changing atmospheric fallout of magnetic particles recorded in recent ombrotrophic peat sections.

    Science.gov (United States)

    Oldfield, F; Thompson, R; Barber, K E

    1978-02-10

    Magnetic measurements of ombrotrophic peat allow a reconstruction of changes in the past fallout of magnetic particles through the atmosphere. In recent peat profiles from three sites in Britain and Northern Ireland, a marked increase in saturated isothermal remanent magnetization of the peat is recorded in levels which can be shown to postdate the onset of the Industrial Revolution. Furthermore the spatial variation in contemporary isothermal remanent magnetization values is consistent with a recent industrial and urban origin for the bulk of the magnetic minerals present. Pre-Industrial Revolution values are between two and three orders of magnitude lower, suggesting that the natural cosmic and terrestrial sources previously cited for such material have been dominated in recent times by the products of human activity. Magnetic measurements provide a simple, rapid, and nondestructive method of monitoring and differentiating various types of particulate atmospheric fallout for both recent and preindustrial times.

  13. Using of peat sorbents in bivalent metals sorption from municipal solid waste landfills leachate

    Energy Technology Data Exchange (ETDEWEB)

    Teirumnieka, E.; Teirumnieks, E. [Rezeknes Augskola, Rezekne (Latvia). Faculty of Engineering; Klavins, M. [Latvia Univ., Riga (Latvia). Faculty of Geography and Earth Sciences

    2009-07-01

    Landfill leachate in acidic regions can pollute surface and ground waters with heavy metals and other pollutants. This study investigated the use of peat as an effective media for removing dissolved metal pollutants. As an adsorbent, peat can effectively remove metals from aqueous solutions. The experiment used 10 grams of peat mixed with heat metal solutions in a reaction vessel at temperatures of 20 degrees C. The solution was analyzed using an inductively coupled plasma optical emission spectrometer. A pH meter was used to measure pH values. The study showed that the maximum adsorption capacity for cobalt (Co) was approximately 75 mg per gram. Adsorption quantity was estimated at 68 per cent, with an initial pH of 5.6. The maximum adsorption capacity for nickel (Ni) was approximately 77 mg per gram, and copper (Cu) was 58 mg per gram with initial pH values of 6.8. Results varied with variations in peat composition and structure. Adsorption affinities correlated with electronegativity and softness. Adsorption capacity of peat for each metal decreased due to the competitive effect of binary and ternary solute systems. Approximately 85 per cent of Ni ions were adsorbed in 30 minutes. It was concluded that the sorption efficiency of the peat decreased with increasing initial concentrations of the metals. The pH levels were influenced by the ion exchange effect in the sorption mechanism. 12 refs., 3 tabs., 7 figs.

  14. Heat transfer problems in gas-cooled solid blankets

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.

    1976-01-01

    In all fusion reactors using the deuterium-tritium fuel cycle, a large fraction approximately 80 percent of the fusion energy will be released as approximately 14 MeV neutrons which must be slowed down in a relatively thick blanket surrounding the plasma, thereby, converting their kinetic energy to high temperature heat which can be continuously removed by a coolant stream and converted in part to electricity in a conventional power turbine. Because of the primary goal of achieving minimum radioactivity, to date Brookhaven blanket concepts have been restricted to the use of some form of solid lithium, with inert gas-cooling and in some design cases, water-cooling of the shell structure. Aluminum and graphite have been identified as very promising structural materials for fusion blankets, and conceptual designs based on these materials have been made. Depending on the thermal loading on the ''first'' wall which surrounds the plasma as well as blanket design, heat transfer problems may be noticeably different in gas-cooled solid blankets. Approaches to solution of heat removal problems as well as explanation of: (a) the after-heat problems in blankets; (b) tritium breeding in solids; and (c) materials selection for radiation shields relative to the minimum activity blanket efforts at Brookhaven are discussed

  15. Recycling of phenolic compounds in Borneo's tropical peat swamp forests.

    Science.gov (United States)

    Yule, Catherine M; Lim, Yau Yan; Lim, Tse Yuen

    2018-02-07

    Tropical peat swamp forests (TPSF) are globally significant carbon stores, sequestering carbon mainly as phenolic polymers and phenolic compounds (particularly as lignin and its derivatives) in peat layers, in plants, and in the acidic blackwaters. Previous studies show that TPSF plants have particularly high levels of phenolic compounds which inhibit the decomposition of organic matter and thus promote peat accumulation. The studies of phenolic compounds are thus crucial to further understand how TPSF function with respect to carbon sequestration. Here we present a study of cycling of phenolic compounds in five forests in Borneo differing in flooding and acidity, leaching of phenolic compounds from senescent Macaranga pruinosa leaves, and absorption of phenolics by M. pruinosa seedlings. The results of the study show that total phenolic content (TPC) in soil and leaves of three species of Macaranga were highest in TPSF followed by freshwater swamp forest and flooded limestone forest, then dry land sites. Highest TPC values were associated with acidity (in TPSF) and waterlogging (in flooded forests). Moreover, phenolic compounds are rapidly leached from fallen senescent leaves, and could be reabsorbed by tree roots and converted into more complex phenolics within the leaves. Extreme conditions-waterlogging and acidity-may facilitate uptake and synthesis of protective phenolic compounds which are essential for impeded decomposition of organic matter in TPSF. Conversely, the ongoing drainage and degradation of TPSF, particularly for conversion to oil palm plantations, reverses the conditions necessary for peat accretion and carbon sequestration.

  16. Layered storage of biogenic methane-enriched gas bubbles in peat: A lumped capacitance model controlled by soil structure

    Science.gov (United States)

    Chen, X.; Comas, X.; Binley, A. M.; Slater, L. D.

    2017-12-01

    Methane can accumulate in the gaseous phase in peats, and enter the atmosphere as gas bubbles with a mass flux higher than that via diffusion and plant-mediated pathways. A complete understanding of the mechanisms regulating bubble storage in peats remains incomplete. We developed a layered model to quantify the storage of gas bubbles over a peat column based on a general lumped capacitance model. This conceptual model was applied to explain the effects of peat structure on bubble storage at different depths observed in a laboratory experiment. A peat monolith was collected from the Everglades, a subtropical wetland located in Florida (USA), and kept submerged in a cuboid chamber over 102 days until gas bubble saturation was achieved. Time-lapse ground-penetrating radar (GPR) was used to estimate changes in gas content of each layer and the corresponding average dimensions of stored gas bubbles. The results highlight a hotspot layer of bubble accumulation at depths between 5 and 10 cm below the monolith surface. Bubbles in this shallow hotspot layer were larger relative to those in deeper layers, whilst the degree of decomposition of the upper layers was generally smaller than that of the lower layers based on von Post humification tests. X-ray Computer tomography (CT) was applied to resin-impregnated peat sections from different depths and the results showed that a higher porosity promotes bubbles storage. The stored gas bubbles were released by changing water levels and the air CH4 concentrations above the peat monolith were measured using a flow-through chamber system to confirm the high CH4 concentration in the stored bubbles. Our findings suggest that bubble capacitance is related to the difference in size between gas bubbles and peat pores. This work has implications for better understanding how changes in water table elevation associated with climate change and sea level rise (particularly for freshwater wetlands near coastal areas like the Everglades) may

  17. Blanket design study for a Commercial Tokamak Hybrid Reactor (CTHR)

    International Nuclear Information System (INIS)

    Chapin, D.L.; Green, L.; Lee, A.Y.; Culbert, M.E.; Kelly, J.L.

    1979-09-01

    The results are presented of a study on two blanket design concepts for application in a Commercial Tokamak Hybrid Reactor (CTHR). Both blankets operate on the U-Pu cycle and are designed to achieve tritium self-sufficiency while maximizing the fissile fuel production within thermal and mechanical design constraints. The two blanket concepts that were evaluated were: (1) a UC fueled, stainless steel clad and structure, helium cooled blanket; and (2) a UO 2 fueled, zircaloy clad, stainless steel structure, boiling water cooled blanket. Two different tritium breeding media, Li 2 O and LiH, were evaluated for use in both blanket concepts. The use of lead as a neutron multiplier or reflector and graphite as a reflector was also considered for both blankets

  18. Reducing beryllium content in mixed bed solid-type breeder blankets

    Energy Technology Data Exchange (ETDEWEB)

    Shimwell, J., E-mail: mail@jshimwell.com [Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Lilley, S.; Morgan, L.; Packer, L.; Kovari, M.; Zheng, S. [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); McMillan, J. [Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2016-11-01

    Highlights: • The ratio of breeder ceramic to neutron multiplier of breeder blankets was varied linearly with depth. • Blankets with varying composition were found to perform better than uniform composition breeder blankets. • It was also possible to reduce the amount of beryllium required by the blanket. - Abstract: Beryllium (Be) is a precious resource with many high value uses, the low energy threshold (n,2n) reaction makes Be an excellent neutron multiplier for use in fusion breeder blankets. Estimates of Be requirements and available resources suggest that this could represent a major supply difficulty for solid-type blanket concepts. Reducing the quantity of Be required by breeder blankets would help to alleviate the problem to some extent. In addition, it is important that the reduction in the Be quantity does not diminish the blanket's performance in key aspects such as the tritium breeding ratio (TBR), energy multiplication and peak nuclear heating. Mixed pebble bed designs allow for the multiplier fraction to be varied throughout the blanket. This neutronics study used MCNP 6 to investigate linear variations of the multiplier fraction in relation to blanket depth, in order to better utilise the important multiplying Be(n,2n) and breeding reactions. Blankets with a uniform multiplier fraction showed little scope for reduction in Be mass. Blankets with varying multiplier fractions were able to simultaneously use 10% less Be, increase the energy amplification by 1%, reduce the peak heating by 7% and maintaining a sufficient TBR when compared to the performance achievable using a uniform composition.

  19. Thermohydraulics design and thermomechanics analysis of two European breeder blanket concepts for DEMO. Pt. 1 and Pt. 2. Pt. 1: BOT helium cooled solid breeding blanket. Pt. 2: Dual coolant self-cooled liquid metal blanket

    International Nuclear Information System (INIS)

    Norajitra, P.

    1995-06-01

    Two different breeding blanket concepts are being elaborated at Forschungszentrum Karlsruhe within the framework of the DEMO breeding blanket development, the concept of a helium cooled solid breeding blanket and the concept of a self-cooled liquid metal blanket. The breeder material used in the first concept is Li 4 SiO 4 as a pebble bed arranged separate from the beryllium pebble bed, which serves as multiplier. The breeder material zone is cooled by several toroidally-radially configurated helium cooling plates which, at the same time, act as reinforcements of the blanket structures. In the liquid metal blanket concept lead-lithium is used both as the breeder material and the coolant. It flows at low velocity in poloidal direction downwards and back in the blanket front zone. In both concepts the First Wall is cooled by helium gas. This report deals with the thermohydraulics design and thermomechanics analysis of the two blanket concepts. The performance data derived from the Monte-Carlo computations serve as a basis for the design calculations. The coolant inlet and outlet temperatures are chosen with the design criteria and the economics aspects taken into account. Uniform temperature distribution in the blanket structures can be achieved by suitable branching and routing of the coolant flows which contributes to reducing decisively the thermal stress. The computations were made using the ABAQUS computer code. The results obtained of the stresses have been evaluated using the ASME code. It can be demonstrated that all maximum values of temperature and stress are below the admissible limit. (orig.) [de

  20. MIT LMFBR blanket research project. Final summary report

    International Nuclear Information System (INIS)

    Driscoll, M.J.

    1983-08-01

    This is a final summary report on an experimental and analytical program for the investigation of LMFBR blanket characteristics carried out at MIT in the period 1969 to 1983. During this span of time, work was carried out on a wide range of subtasks, ranging from neutronic and photonic measurements in mockups of blankets using the Blanket Test Facility at the MIT Research Reactor, to analytic/numerical investigations of blanket design and economics. The main function of this report is to serve as a resource document which will permit ready reference to the more detailed topical reports and theses issued over the years on the various aspects of project activities. In addition, one aspect of work completed during the final year of the project, on doubly-heterogeneous blanket configurations, is documented for the record

  1. Thermal-hydraulics design comparisons for the tandem mirror hybrid reactor blanket

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Yang, Y.S.; Schultz, K.R.

    1980-09-01

    The Tandem Mirror Hybrid Reactor (TMHR) is a cylindrical reactor, and the fertile materials and tritium breeding fuel elements can be arranged with radial or axial orientation in the blanket module. Thermal-hydraulics performance comparisons were made between plate, axial rod and radial rod fuel geometrices. The three configurations result in different coolant/void fractions and different clad/structure fractions. The higher void fraction in the two rod designs means that these blankets will have to be thicker than the plate design blanket in order to achieve the same level of nuclear interactions. Their higher structural fractions will degrade the uranium breeding ratio and energy multiplication factor of the design. One difficulty in the thermal-hydraulics analysis of the plate design was caused by the varying energy multiplication of the blanket during the lifetime of the plate which forced the use of designs that operated in the transition flow regime at some point during life. To account for this, an approach was adopted from Gas Cooled Fast Reactor (GCFR) experience for the pressure drop calculation and the corresponding heat transfer coefficient that was used for the film drop thermal calculation. Because of the superior nuclear performance, the acceptable thermal-hydraulic characteristics and the mechanical design feasibility, the plate geometry concept was chosen for the reference gas-cooled TMHR blanket design

  2. Distribution and speciation of mercury in the peat bog of Xiaoxing'an Mountain, northeastern China

    International Nuclear Information System (INIS)

    Liu Ruhai; Wang Qichao; Lu Xianguo; Fang Fengman; Wang Yan

    2003-01-01

    Peat bogs in northeastern China contain high levels of mercury from atmospheric deposition. - Most reports on mercury (Hg) in boreal ecosystems are from the Nordic countries and North America. Comparatively little information is available on Hg in wetlands in China. We present here a study on Hg in the Tangwang River forested catchment of the Xiaoxing'an Mountain in the northeast of China. The average total Hg (THg) in peat profile ranged from 65.8 to 186.6 ng g -1 dry wt with the highest at the depth of 5-10 cm. THg in the peat surface was higher than the background in Heilongjiang province, the Florida Everglades, and Birkeness in Sweden. MethylHg (MeHg) concentration ranged from 0.16 to 1.86 ng g -1 dry wt, with the highest amount at 10-15 cm depth. MeHg content was 0.2-1.2% of THg. THg and MeHg all decreased with the depth. THg in upland layer of soil (0-20 cm) was comparable to the peat surface, but in deeper layers THg concentration in peat was much higher than that in the forested mineral soil. THg in the peat bog increased, but MeHg decreased after it was drained. THg content in plant was different; THg contents in moss (119 ng g -1 dry wt, n=12) were much higher than in the herbage, the arbor, and the shrubs. The peat bog has mainly been contaminated by Hg deposition from the atmosphere

  3. Impact of a commercial peat moss operation on water quality and biota in a small tributary of the Richibucto River, Kent County, New Brunswick, Canada.

    Science.gov (United States)

    Surette, C; Brun, G L; Mallet, V N

    2002-05-01

    The St-Charles Plain (Kent County, New Brunswick, Canada) commercial peat moss operation has been ongoing since 1983. To process the peat, a dry extraction method is used that requires extensive drainage of the peat bog. The water is directed toward sedimentation ponds, where it drains into a small brook, which feeds into a river affected by tidal salt water. Water discharge from the bog contains large amounts of peat particles that deposit in the surrounding watershed. As a result, the pH of the freshwater sites that receive the drainage water from the commercial operation, is fairly acidic (pH 3.9-4.7). Water samples from or near the peat moss operation have a higher concentration of total phosphorous and total organic carbon. The peat particles contain relatively high levels of total mercury, as reflected by analysis of peat sediments. However, the water samples contained low levels of dissolved mercury. Indigenous samples of biota-namely, sand shrimps (Crangon septemspinosa) and mummichogs (Fundulus heteroclitus)-did not contain mercury levels higher in the impacted sites than in the reference sites. Introduced blue mussels (Mytilus edulis) did not accumulate significant amounts of mercury during a 62-day exposure in the study area. Overall, the data suggest that although relatively large amounts of mercury-containing peat particles are discharged into the ecosystem, bioaccumulation of mercury in the biota does not occur.

  4. Utilization of new materials in peat machines; Uusien materiaalien kaeyttoe turvekoneissa

    Energy Technology Data Exchange (ETDEWEB)

    Kallio, M.; Poeyhoenen, P. [VTT Energy, Jyvaeskylae (Finland)

    1997-12-01

    The objective of this three year research (1993-1995) was to study the suitability of new materials for different applications in peat production industry, exploiting the plastic and brush technologies, and surface coatings. The peat production machines will be intensified, lightened, made more firesafe, and ergonomical by using new materials (plastics, composites, compound metals and surface coatings). The research targets and materials were surveyed in 1993, the possibilities to construct an unsparkling miller were investigated, and low-friction materials, on which the peat glides easily, were sought in the beginning of the research. The unsparkling miller was studied and developed further in 1994 using plastic blades, the application of brushing technology in sod peat technology, and a ridger, equipped with horizontal brushes, for sod peat were studied, and the possibilities to lighten the construction of the collector-wagon using light materials was investigated. The tasks for 1995 were to study the brushing technology for peat production, the properties of the bristle, and the applications of new materials for milling and sieving of peat using laboratory tests. This work continued partly in 1996

  5. Vesicular-arbuscular mycorrhizal status of plant species in the peat swamp forest of Setia Alam Jaya, Sebangau, Central Kalimantan

    Directory of Open Access Journals (Sweden)

    Suciatmih Suciatmih

    2003-06-01

    Full Text Available In order to describe the vesicular-arbuscular mycorrhizal (VAM status of plants growing on peat soil, a study was carried out inthe peat swamp forest of Setia Alam Jaya in Sebangau, Central Kalimantan. Out of 146 plant root samples belonging to 48 plantspecies from 25 families examined, all plants colonized by VAM fungi namely 14 (29.2% high level, 32 (66.7% medium level, and 2(4.1% low level respectively.

  6. Simulation Model of Automated Peat Briquetting Press Drive

    Directory of Open Access Journals (Sweden)

    A. A. Marozka

    2012-01-01

    Full Text Available The paper presents the developed fully functional simulation model of an automated peat briquetting press drive. The given model makes it possible to reduce financial and time costs while developing, designing and operating a double-stamp peat briquetting press drive.

  7. Thermomechanical analysis of the DFLL test blanket module for ITER

    International Nuclear Information System (INIS)

    Chen Hongli; Wu Yican; Bai Yunqing

    2006-01-01

    The finite element code is used to simulate two kinds of blanket design structure, which are SLL (Quasi-Static Lithium Lead) and DLL (Dual-cooled Lithium Lead) blanket concepts for the Dual Functional Lithium Lead-Test Blanket Module (DFLL-TBM) submitted to the ITER test blanket working group. The temperature and stress distributions have been presented for the two kinds of blanket structure on the basis of the structural design, thermal-hydraulic design and neutronics analysis. Also the mechanical performance is presented for the high temperature component of blanket structure according to the ITER Structural Design Criteria (ISDC). The rationality and feasibility of the two kinds of blanket structure design of DFLL-TBM have been analyzed based on the above results which also acted as the theoretical base for further optimized analysis. (authors)

  8. Weeds optimally grow in peat swamp after burning

    Directory of Open Access Journals (Sweden)

    P.D. Susanti

    2014-07-01

    Full Text Available After clearing land by burning the peat, then the weeds and undergrowth will flourish. Even sometimes, the weeds are eventually burned again. Weed is known as a destroyer plant that has to be controlled. Through proper treatment, the existing weeds in peatlands can be potentiallly exploited. The purpose of this study was to determine the calorific value of briquettes as one of peatland weeds utilization. The results showed that the calorific value ranged from 2,492 cal/g to 5,230 cal/g. The lowest calorific value was on ‘teki kecil’ grass (Scirpus grossus Lf, while the highest calorific value was observed for ‘bantalaki grass’ (Hymenachne amplexicaulis Nees. The high calorific value of the peat weeds are potential for biomass briquettes raw materials. The utilization and use of peat weed briquettes as a raw materials expected can reduce land degradation due to peat swamp burning

  9. Coastal landforms and accumulation of mangrove peat increase carbon sequestration and storage.

    Science.gov (United States)

    Ezcurra, Paula; Ezcurra, Exequiel; Garcillán, Pedro P; Costa, Matthew T; Aburto-Oropeza, Octavio

    2016-04-19

    Given their relatively small area, mangroves and their organic sediments are of disproportionate importance to global carbon sequestration and carbon storage. Peat deposition and preservation allows some mangroves to accrete vertically and keep pace with sea-level rise by growing on their own root remains. In this study we show that mangroves in desert inlets in the coasts of the Baja California have been accumulating root peat for nearly 2,000 y and harbor a belowground carbon content of 900-34,00 Mg C/ha, with an average value of 1,130 (± 128) Mg C/ha, and a belowground carbon accumulation similar to that found under some of the tallest tropical mangroves in the Mexican Pacific coast. The depth-age curve for the mangrove sediments of Baja California indicates that sea level in the peninsula has been rising at a mean rate of 0.70 mm/y (± 0.07) during the last 17 centuries, a value similar to the rates of sea-level rise estimated for the Caribbean during a comparable period. By accreting on their own accumulated peat, these desert mangroves store large amounts of carbon in their sediments. We estimate that mangroves and halophyte scrubs in Mexico's arid northwest, with less than 1% of the terrestrial area, store in their belowground sediments around 28% of the total belowground carbon pool of the whole region.

  10. Regulations for the peat production water pollution control

    International Nuclear Information System (INIS)

    Savolainen, M.; Heikkinen, K.; Ihme, R.

    1996-01-01

    The regulations for peat production water pollution control include the latest information on anti-pollution constructions applicable to peat production including field ditches, sedimentation basins, overland flow areas, forest soil saturation, evaporation basins, chemicalization, detention of runoff and artificial flood plains. Information on subsurface drainage in peat mining is also given. The regulations deal with environmental viewpoints, planning of water protection and information on how to build, use and maintain anti-pollution constructions. Special attention is given to the soil conditions, because they play an important role in the building of different constructions. (orig.) (48 refs.)

  11. Progress in fusion reactors blanket analysis and evaluation at CEA

    International Nuclear Information System (INIS)

    Proust, E.; Gervaise, F.; Carre, F.; Chevereau, G.; Doutriaux, D.

    1986-09-01

    In the frame of the recent CEA studies aiming at the development, evaluation and comparison of solid breeder blanket concepts in view of their adaptation to NET, the evaluation of specific questions related to the first wall design, the present paper examines first the performances of a helium cooled toroidal blanket design for NET, based on innovative Beryllium/Ceramics breeder rod elements. Neutronic and thermo-mechanical optimisation converges on a concept featured by a breeding capability in excess of 1.2, a reasonnable pumping power of 1% and a narrow breeder temperature range (470+-30 deg C of the breeder), the latter being largely independent of the power level. This design proves naturally adapted to ceramic breeder assigned to very strict working conditions, and provides for any change in the thermal and heat transfer characteristics over the blanket lifetime. The final section of the paper is devoted to the evaluation of the heat load poloidal distribution and to the irradiation effects on first wall structural materials

  12. Regional Haze Evolved from Peat Fires - an Overview

    Science.gov (United States)

    Hu, Yuqi; Rein, Guillermo

    2016-04-01

    This work provides an overview of haze episodes, their cause, emissions and health effects found in the scientific literature. Peatlands, the terrestrial ecosystems resulting from the accumulation of partially decayed vegetation, become susceptible to smouldering fires because of natural droughts or anthropogenic-induced drainages. Once ignited, smouldering peat fires persistently consume large amounts of soil carbon in a flameless form. It is estimated that the average annual carbon gas emissions (mainly CO2 and CO) from peat fires are equivalent to 15% of manmade emissions, representing influential perturbation of global carbon circle. In addition to carbon emissions, smouldering peat fires emit substantial quantities of heterogeneous smoke, which is responsible for haze phenomena, has not yet been fully studied. Peat-fire-derived smoke is characterized by high concentration of particulate matter (PM), ranging from nano-scale ultrafine fraction (PM1, particle diameter condition, and then low buoyant smoke plume could accumulate and migrate long distances, leading to regional haze. Apart from air quality deterioration, haze leads to severe reduction in visibility, which strongly affects local transportation, construction, tourism and agriculture-based industries. For example, an unprecedented peatland mega-fire burst on the Indonesian islands Kalimantan and Sumatra during the 1997 El-Niño event, resulting in transboundary smoke-haze disaster. Severe haze events continue to appear in Southeast Asia every few years due to periodical peat fires in this region. In addition, smouldering peat fires have been frequently reported in tropical, temperate and boreal regions (Botswana in 2000, North America in 2004, Scotland in 2006 and Central Russia in 2010 et al.), peat-fire-induced haze has become a regional seasonal phenomenon. Exposure to smoky haze results in deleterious physiologic responses, predominantly to the respiratory and cardiovascular systems. In 1997, an

  13. Presentation of the results of 1993-1994 of the peat production research area; Turvetuotanto - tutkimusalueen katsaus

    Energy Technology Data Exchange (ETDEWEB)

    Leinonen, A.

    1996-12-31

    The development target of the peat production research area of the Biomass research programme is to improve the competitivity of peat by reducing the production costs by 20 % (5-6 FIM/MWh) from the level of 1992 and to reduce the environmental load. The main targets of peat production, by which the target can be met, are ditching and preparation technologies, drying technology, machine technology, methodology, integration of wood harvesting and peat production, and application of the results of the Optimiturve research programme in practice. The objectives of the peat production research are possible to meet if the partial targets are met. Increment of the open-ditch distance from 20 m to 60 m reduces the production costs by 5.0 %, increment of the rate of utilization of solar radiation from 30 % to 40 % reduces the production costs by 8 %, reduction of the amount of residual peat from 3000 MWh to 1500 MWh reduces the costs by 6.5 %, development of light and firesafe machines by 3 %, and integrated harvesting of wood by 3 %. Meeting of the partial targets reduces the production costs by 24 %. The main research areas of peat production will be carried out further. The total funding of the peat production researches in 1993-1994 was 19.4 million FIM (9.7 million FIM/a). The share of the total funding of the research organization projects has been 6.7 million FIM and that of the company projects 12.7 million FIM. The share of the Finnish Ministry of Trade and Industry of the funding has been 9.0 million FIM (46 %)

  14. Blanket options for high-efficiency fusion power

    International Nuclear Information System (INIS)

    Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

    1980-01-01

    The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

  15. Fusion blankets for high-efficiency power cycles

    International Nuclear Information System (INIS)

    Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

    1980-01-01

    The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

  16. Fusion blanket for high-efficiency power cycles

    International Nuclear Information System (INIS)

    Usher, J.L.; Powell, J.R.; Fillo, J.A.; Horn, F.L.; Lazareth, O.W.; Taussig, R.

    1980-01-01

    The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperature (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by Ar) utilizing Li 2 O for tritium breeding. In this design, approx. 60% of the fusion energy is deposited in the high-temperature interior. The maximum Ar temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

  17. Fusion blankets for high-efficiency power cycles

    International Nuclear Information System (INIS)

    Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

    1981-01-01

    The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 deg C) of conventional structural materials such as stainless steels. In this project 'two-zone' blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 deg C leading to an overall efficiency estimate of 55 to 60% for this reference case. (author)

  18. Investigation of metal ions sorption of brown peat moss powder

    Science.gov (United States)

    Kelus, Nadezhda; Blokhina, Elena; Novikov, Dmitry; Novikova, Yaroslavna; Chuchalin, Vladimir

    2017-11-01

    For regularities research of sorptive extraction of heavy metal ions by cellulose and its derivates from aquatic solution of electrolytes it is necessary to find possible mechanism of sorption process and to choice a model describing this process. The present article investigates the regularities of aliovalent metals sorption on brown peat moss powder. The results show that sorption isotherm of Al3+ ions is described by Freundlich isotherm and sorption isotherms of Na+ i Ni2+ are described by Langmuir isotherm. To identify the mechanisms of brown peat moss powder sorption the IR-spectra of the initial brown peat moss powder samples and brown peat moss powder samples after Ni (II) sorption were studied. Metal ion binding mechanisms by brown peat moss powder points to ion exchange, physical adsorption, and complex formation with hydroxyl and carboxyl groups.

  19. Climate impact from peat utilisation in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Uppenberg, S.; Zetterberg, L.; Aahman, M.

    2001-08-01

    The climate impact from the use of peat for energy production in Sweden has been evaluated in terms of contribution to atmospheric radiative forcing. This was done by attempting to answer the question 'What will be the climate impact if one would use 1 m{sup 2} of mire for peat extraction during 20 years?'. Two different methods of after-treatment were studied: afforestation and restoration of wetland. The climate impact from a peatland - wetland energy scenario and a peatland - forestry energy scenario was compared to the climate impact from coal, natural gas and forest residues. Sensitivity analyses were performed to evaluate which parameters that are important to take into consideration in order to minimize the climate impact from peat utilisation.

  20. Climate impact from peat utilisation in Sweden

    International Nuclear Information System (INIS)

    Uppenberg, S.; Zetterberg, L.; Aahman, M.

    2001-08-01

    The climate impact from the use of peat for energy production in Sweden has been evaluated in terms of contribution to atmospheric radiative forcing. This was done by attempting to answer the question 'What will be the climate impact if one would use 1 m 2 of mire for peat extraction during 20 years?'. Two different methods of after-treatment were studied: afforestation and restoration of wetland. The climate impact from a peatland - wetland energy scenario and a peatland - forestry energy scenario was compared to the climate impact from coal, natural gas and forest residues. Sensitivity analyses were performed to evaluate which parameters that are important to take into consideration in order to minimize the climate impact from peat utilisation

  1. The future role of peat. The Finnish Ministry of Trade and Industry's investigation on the role of peat in the greenhouse gas balance in Finland

    International Nuclear Information System (INIS)

    Knuutinen, O.

    2000-01-01

    Due to contradictory opinions on the role of peat as a renewable energy source and carbon sink as well as the fact that no comprehensive research are made in this area, the Finnish Ministry of Trade and Industry (KTM) assigned an impartial working group to investigate the role of peat in climatic change. The working group consists of Patrick Crill from USA, Ken Hargreaves from Great Britain, and Atte Korhola from Finland. The objective of the working group is to study the greenhouse gas balances of virgin peatland, ditched peatlands, and cultivated peatlands. The carbon cycles will be investigated, as well as the effects of utilisation of peat on greenhouse gas balance, and the possibilities of effecting the balance with active measures. The alternatives for utilisation peatlands after the peat has been harvested, and the effects of these alternatives on greenhouse gas balance will also be studied. The effects of the peatlands left in passive natural state, the regeneration of peatlands, forestation and other usage on greenhouse gas balance will be investigated, and the need for regulations and instructions for recycling have to be estimated. The greenhouse gas emissions and the carbon sinks have to be defined, the alternative means for definition of them have to be inspected. The mutual dependence of peat and wood fuels has also to be taken into consideration. The report will to include the effects of peat on watercourses, versatility of the nature, the effect of the peat production on the amount of peat production areas, and suggestions for possible need of further investigations

  2. Palaeoecology of Holocene peat deposits from Nordvestø, north-west Greenland

    DEFF Research Database (Denmark)

    Bennike, Ole; Goodsite, Michael Evan; Heinemeier, Jan

    2008-01-01

    Two extensive peat deposits on Nordvestø, between Greenland and Canada, were examined for macroscopic remains of plants and animals. One of the peat deposits accumulated during the period from c. 7,100 to 5,100 cal. years BP. This peat is guanogenic and completely dominated by the coprophilous...... bryophyte Aplodon wormskioldii, and also contains frequent remains of feathers. The peat formed close to a large former sea bird colony, probably a puffin (Fratercula arctica) colony. Puffins are now rare in the region, but the population may have been larger during the mid Holocene, when the sea was ice......-free for a longer period than at present. The other peat deposit is dated to c. 9,300-7,400 cal. years BP, it is minerogenic and the macrofossils reflect deposition in a shallow, richly vegetated pond. This peat formed during warmer summers than at present....

  3. Biosorption of mercury from aqueous solutions using highly characterised peats

    Directory of Open Access Journals (Sweden)

    A.M. Rizzuti

    2015-02-01

    Full Text Available This research investigated the biosorption of mercury from aqueous solutions by six highly characterised peats. Samples of the peats were tested both in unaltered condition and after being treated with hydrochloric acid (HCl to free up any occupied exchange sites. Other variables tested were sample dose, contact time, mixing temperature, and the concentration and pH of the mercury solution. Desorption studies were also performed, and tests were done to determine whether the peats could be re-used for mercury biosorption. The results indicate that all six peat types biosorb mercury from aqueous solutions extremely well (92−100 % removal and that their mercury removal capacities are not significantly affected by manipulation of the various factors tested. The factor that had the greatest impact on the mercury removal capacities of the peats was the pH of the mercury solution. The optimal mercury solution pH for mercury removal was in the range 5−7 for four of the peats and in the range 2−3 for the other two. The desorption results indicate that it may be possible to recover up to 41 % of the removed mercury. All of the peat types tested can be repeatedly re-used for additional mercury biosorption cycles. Hence, their disposal should not become a hazardous waste problem.

  4. Ground-penetrating radar study of the Rahivere peat bog, eastern Estonia

    Directory of Open Access Journals (Sweden)

    Jüri Plado

    2011-03-01

    Full Text Available The current case study presents results of the ground-penetrating radar (GPR profiling at one of the Saadjärve drumlin field interstitial troughs, the Rahivere bog, eastern Estonia. The study was conducted in order to identify the bog morphology, and the thickness and geometry of the peat body. The method was also used to describe the applicability of GPR in the evaluation of the peat deposit reserve as the Rahivere bog belongs among the officially registered peat reserves. Fourteen GPR profiles, ~ 100 m apart and oriented perpendicular to the long axis of the depression, covering the bog and its surrounding areas, were acquired. In order to verify the radar image interpretation as well as to evaluate the velocity of electromagnetic waves in peat, a common source configuration was utilized and thirteen boreholes were drilled on the GPR profiles. A mean value of 0.036 m ns–1 corresponding to relative dielectric permittivity of 69.7 was used for the time–depth conversion. Radar images reveal major reflection from the peat–soil interface up to a depth of about 4 m, whereas drillings showed a maximum thickness of 4.5 m of peat. Minor reflections appear from the upper peat and mineral soil. According to the borehole data, undecomposed peat is underlain by decomposed one, but identifying them by GPR is complicated. Mineral soil consists of glaciolimnic silty sand in the peripheral areas of the trough, overlain by limnic clay in the central part. The calculated peat volumes (1 200 000 m3 were found to exceed the earlier estimation (979 000 m3 that was based solely on drilling data. Ground-penetrating radar, as a method that allows mapping horizontal continuity of the sub-peat interface in a non-destructive way, was found to provide detailed information for evaluating peat depth and extent.

  5. High nitrogen availability reduces polyphenol content in Sphagnum peat.

    Science.gov (United States)

    Bragazza, Luca; Freeman, Chris

    2007-05-15

    Peat mosses of the genus Sphagnum constitute the bulk of living and dead biomass in bogs. These plants contain peculiar polyphenols which hamper litter peat decomposition through their inhibitory activity on microbial breakdown. In the light of the increasing availability of biologically active nitrogen in natural ecosystems, litter derived from Sphagnum mosses is an ideal substrate to test the potential effects of increased atmospheric nitrogen deposition on polyphenol content in litter peat. To this aim, we measured total nitrogen and soluble polyphenol concentration in Sphagnum litter peat collected in 11 European bogs under a chronic gradient of atmospheric nitrogen deposition. Our results demonstrate that increasing nitrogen concentration in Sphagnum litter, as a consequence of increased exogenous nitrogen availability, is accompanied by a decreasing concentration of polyphenols. This inverse relationship is consistent with reports that in Sphagnum mosses, polyphenol and protein biosynthesis compete for the same precursor. Our observation of modified Sphagnum litter chemistry under chronic nitrogen eutrophication has implications in the context of the global carbon balance, because a lower content of decay-inhibiting polyphenols would accelerate litter peat decomposition.

  6. Methods to enhance blanket power density

    International Nuclear Information System (INIS)

    Hsu, P.Y.; Miller, L.G.; Bohn, T.S.; Deis, G.A.; Longhurst, G.R.; Masson, L.S.; Wessol, D.E.; Abdou, M.A.

    1982-06-01

    The overall objective of this task is to investigate the extent to which the power density in the FED/INTOR breeder blanket test modules can be enhanced by artificial means. Assuming a viable approach can be developed, it will allow advanced reactor blanket modules to be tested on FED/INTOR under representative conditions

  7. Neutronic optimization of solid breeder blankets for STARFIRE design

    International Nuclear Information System (INIS)

    Gohar, Y.; Abdou, M.A.

    1980-01-01

    Extensive neutronic tradeoff studies were carried out to define and optimize the neutronic performance of the different solid breeder options for the STARFIRE blanket design. A set of criteria were employed to select the potential blanket materials. The basic criteria include the neutronic performance, tritium-release characteristics, material compatibility, and chemical stability. Three blanket options were analyzed. The first option is based on separate zones for each basic blanket function where the neutron multiplier is kept in a separate zone. The second option is a heterogeneous blanket type with two tritium breeder zones. In the first zone the tritium breeder is assembled in a neutron multiplier matrix behind the first wall while the second zone has a neutron moderator matrix instead of the neutron multiplier. The third blanket option is similar to the second concept except the tritium breeder and the neutron multiplier form a homogeneous mixture

  8. Study of settling of peat on channel banks

    Energy Technology Data Exchange (ETDEWEB)

    Amaryan, L S; Bazin, Ye T; Stepanichev, V G

    1983-01-01

    Results are presented of studies of settling of the peat formation of the upper type on banks of drying channels. A technique is presented for forecasting evaluation in the decrease in depth of the channels because of packing of the peat on the sides of the dryers.

  9. Development of advanced blanket materials for solid breeder blanket of fusion reactor

    International Nuclear Information System (INIS)

    Ishitsuka, E.

    2002-01-01

    Advanced solid breeding blanket design in the DEMO reactor requires the tritium breeder and neutron multiplier that can withstand the high temperature and high dose of neutron irradiation. Therefore, the development of such advanced blanket materials is indispensable. In this paper, the cooperation activities among JAERI, universities and industries in Japan on the development of these advanced materials are reported. Advanced tritium breeding material to prevent the grain growth in high temperature had to be developed because the tritium release behavior degraded by the grain growth. As one of such materials, TiO 2 -doped Li 2 TiO 3 has been studied, and TiO 2 -doped Li 2 TiO 3 pebbles was successfully fabricated. For the advanced neutron multiplier, the beryllium intermetallic compounds that have high melting point and good chemical stability have been studied. Some characterization of Be 12 Ti was studied. The pebble fabrication study for Be 12 Ti was also performed and Be 12 Ti pebbles were successfully fabricated. From these activities, the bright prospect to realize the DEMO blanket by the application of TiO 2 -doped Li 2 TiO 3 and beryllium intermetallic compounds was obtained. (author)

  10. Estonian horticultural peat marketing: sales promotion and price formation. 2. part

    International Nuclear Information System (INIS)

    Hammer, Hele

    1999-01-01

    When forming prices, Estonian peat companies' decisions should be based on marginal cost analysis. Unfortunately most Estonian companies sell peat to intermediaries and cannot influence its price. Estonian peat producers have to choose between either selling peat directly or selling through a central marketing organization. Both systems have their pros and cons. Direct selling gives more freedom to individual producers but is more risky. Central marketing makes cost saving possible and is more effective and stable, but may alienate producers from clients and markets. Whichever marketing system Estonian peat companies choose, the most important elements in their marketing strategy should be: careful market analysis, personal sales, attending trade shows, catalogues, quality service and offering transportation services. (author)

  11. Neutronics Evaluation of Lithium-Based Ternary Alloys in IFE Blankets

    Energy Technology Data Exchange (ETDEWEB)

    Jolodosky, A. [Univ. of California, Berkeley, CA (United States); Fratoni, M. [Univ. of California, Berkeley, CA (United States)

    2015-09-22

    Lithium is often the preferred choice as breeder and coolant in fusion blankets as it offers excellent heat transfer and corrosion properties, and most importantly, it has a very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and exacerbates plant safety concerns. For this reason, over the years numerous blanket concepts have been proposed with the scope of reducing concerns associated with lithium. The European helium cooled pebble bed breeding blanket (HCPB) physically confines lithium within ceramic pebbles. The pebbles reside within a low activation martensitic ferritic steel structure and are cooled by helium. The blanket is composed of the tritium breeding lithium ceramic pebbles and neutron multiplying beryllium pebbles. Other blanket designs utilize lead to lower chemical reactivity; LiPb alone can serve as a breeder, coolant, neutron multiplier, and tritium carrier. Blankets employing LiPb coolants alongside silicon carbide structural components can achieve high plant efficiency, low afterheat, and low operation pressures. This alloy can also be used alongside of helium such as in the dual-coolant lead-lithium concept (DCLL); helium is utilized to cool the first wall and structural components made up of low-activation ferritic steel, whereas lithium-lead (LiPb) acts as a self-cooled breeder in the inner channels of the blanket. The helium-cooled steel and lead-lithium alloy are separated by flow channel inserts (usually made out of silicon carbide) which thermally insulate the self-cooled breeder region from the helium cooled steel walls. This creates a LiPb breeder with a much higher exit temperature than the steel which increases the power cycle efficiency and also lowers the magnetohydrodynamic (MHD) pressure drop [6]. Molten salt blankets with a mixture of lithium, beryllium, and fluorides (FLiBe) offer good tritium breeding

  12. TEHOPALA - Intensification of peat production; TEHOPALA - palaturvetuotannon tehostaminen

    Energy Technology Data Exchange (ETDEWEB)

    Nurminen, T.; Katainen, E. [Vapo Oy, Jyvaeskylae (Finland); Leinonen, A.; Aalto, J. [VTT Energy, Jyvaeskylae (Finland); Hoelttae, P. [Biomasters Oy, Oulu (Finland)

    1996-12-31

    The objective of the Tehopala project is to increase the hectare yield of sod peat by 50 % and to reduce the production costs by 30 % by developing the sod peat production methods and equipment. The main aim of the research is in machine development, the target of which is to develop a new efficient machine chain for ridge-drying method. A new more effective cutting disc, suitable for 600 mm nozzles for production wave-like sod, has been developed for PK-1S sod peat excavator. The RYT-MP excavator has been developed to operationally reliable stage, and a nozzle for production of wave-like sod has been constructed for it. Prototype machines have been developed for ridging and loading. The development work of these will be carried out further. Ridge-drying method and wave-like sod peat method have been proven to be more effective than the cylindrical sod technology and field-drying method

  13. Studies on sphagnum peat. III. A quantitative study on the carbohydrate constituents of sphagnum mosses and sphagnum peat

    Energy Technology Data Exchange (ETDEWEB)

    Theander, O

    1954-01-01

    A qualitative and a quantitative investigation of the carbohydrates in two sphagnum mosses and five samples of sphagnum peat of different age and degree of huminosity has been performed. The two mosses investigated showed no significant differences. Samples of very different age but with the same degree of physical huminosity were very similar, indicating that the chief changes occur at the top of the bog and/or are determined by the conditions at the start of the humification. The total amount of carbohydrates was about 90% of the organic material in the mosses and about 65% and 35% in peats with a degree of huminosity of 3-4 and 6-7 respectively. Of the constituent sugars, fructose which occurred in the mosses, was completely absent in the peat. Another sugar, which occurs in nature as a furanoside, arabinose, disappeared almost completely during the humification. The uronic acids and galactose decreased faster, while ylose and glucose decreased at about the same rate as the total carbohydrates. Mannose and probably also rhamnose are the most stable components and accumulate during the humification. The polysaccharides in mosses and peat seem to constitute a very complex mixture. The presence of a fructan in the living moss, of a polyuronide (pectin) and a large amount of more complex polysaccharides built up of galactose, xylose, rhamnose and uronic acids is indicated. The glucose, the most important constituent, probably occurs chiefly as cellulose, the presence of which has been demonstrated by other workers. Finally the behaviour of mannose during the humification indicates the presence of a stable mannan. There is no evidence of polysaccharides formed by microorganisms in the peat.

  14. Influence of Biodegradation on the Organic Compounds Composition of Peat.

    Science.gov (United States)

    Serebrennikova, Olga; Svarovskaya, Lidiya; Duchko, Maria; Strelnikova, Evgeniya; Russkikh, Irina

    2016-06-01

    Largest wetland systems are situated on the territory of the Tomsk region. They are characterized by the high content of organic matter (OM), which undergoes transformation as a result of physical, chemical and biological processes. The composition of peat OM is determined by the nature of initial peat-forming plants, their transformation products and bacteria. An experiment in stimulated microbial impact was carried out for estimating the influence of biodegradation on the composition of peat lipids. The composition of the functional groups in the bacterial biomass, initial peat and peat after biodegradation was determined by IR-spectroscopy using the spectrometer NICOLET 5700. The IR spectra of peat and bacteria organic matter are characterized by the presence of absorption bands in ranges: 3400-3200 cm-1, which refers to the stretching vibrations of OH-group of carboxylic acids and various types of hydrogen bonds; 1738-1671 cm-1 - characteristic stretching vibrations of the C = O group of carboxylic acids and ketones; 1262 cm-1 - stretching vibrations of C-O of carboxylic acids. Group and individual composition of organic compounds in studied samples was determined by gas chromatography-mass-spectrometry.

  15. Review: BNL Tokamak graphite blanket design concepts

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.

    1976-01-01

    The BNL minimum activity graphite blanket designs are reviewed, and three are discussed in the context of an experimental power reactor (EPR) and commercial power reactor. Basically, the three designs employ a 30 cm or thicker graphite screen. Bremsstrahlung energy is deposited on the graphite surface and re-radiated away as thermal radiation. Fast neutrons are slowed down in the graphite, depositing most of their energy, which is then radiated to a secondary blanket with coolant tubes, as in types A and B, or removed by intermittent direct gas cooling (type C). In types A and B, radiation damage to the coolant tubes in the secondary blanket is reduced by one or two orders of magnitude, while in type C, the blanket is only cooled when the reactor is shut down, so that coolant cannot quench the plasma. (Auth.)

  16. Experience of Milled Peat Burning at Thermal Electric Power Plant

    Directory of Open Access Journals (Sweden)

    G. I. Zhikhar

    2013-01-01

    Full Text Available The paper presents extensive knowledge and practical experience on burning of milled peat in the boilers of thermal electric power plants in Belarus and Russia. The accumulated experience can be used for solution of problems pertaining to substitution of some types of fuel imported to Belarus by milled peat which is extracted at many fuel effective peat enterprises of the Republic.

  17. Blanket/first wall challenges and required R&D on the pathway to DEMO

    International Nuclear Information System (INIS)

    Abdou, Mohamed; Morley, Neil B.; Smolentsev, Sergey; Ying, Alice; Malang, Siegfried; Rowcliffe, Arthur; Ulrickson, Mike

    2015-01-01

    The breeding blanket with integrated first wall (FW) is the key nuclear component for power extraction, tritium fuel sustainability, and radiation shielding in fusion reactors. The ITER device will address plasma burn physics and plasma support technology, but it does not have a breeding blanket. Current activities to develop “roadmaps” for realizing fusion power recognize the blanket/FW as one of the principal remaining challenges. Therefore, a central element of the current planning activities is focused on the question: what are the research and major facilities required to develop the blanket/FW to a level which enables the design, construction and successful operation of a fusion DEMO? The principal challenges in the development of the blanket/FW are: (1) the Fusion Nuclear Environment – a multiple-field environment (neutrons, heat/particle fluxes, magnetic field, etc.) with high magnitudes and steep gradients and transients; (2) Nuclear Heating in a large volume with sharp gradients – the nuclear heating drives most blanket phenomena, but accurate simulation of this nuclear heating can be done only in a DT-plasma based facility; and (3) Complex Configuration with blanket/first wall/divertor inside the vacuum vessel – the consequence is low fault tolerance and long repair/replacement time. These blanket/FW development challenges result in critical consequences: (a) non-fusion facilities (laboratory experiments) need to be substantial to simulate multiple fields/multiple effects and must be accompanied by extensive modeling; (b) results from non-fusion facilities will be limited and will not fully resolve key technical issues. A DT-plasma based fusion nuclear science facility (FNSF) is required to perform “multiple effects” and “integrated” experiments in the fusion nuclear environment; and (c) the Reliability/Availability/Maintainability/Inspectability (RAMI) of fusion nuclear components is a major challenge and is one of the primary reasons

  18. Blanket/first wall challenges and required R&D on the pathway to DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Abdou, Mohamed, E-mail: abdou@fusion.ucla.edu; Morley, Neil B.; Smolentsev, Sergey; Ying, Alice; Malang, Siegfried; Rowcliffe, Arthur; Ulrickson, Mike

    2015-11-15

    The breeding blanket with integrated first wall (FW) is the key nuclear component for power extraction, tritium fuel sustainability, and radiation shielding in fusion reactors. The ITER device will address plasma burn physics and plasma support technology, but it does not have a breeding blanket. Current activities to develop “roadmaps” for realizing fusion power recognize the blanket/FW as one of the principal remaining challenges. Therefore, a central element of the current planning activities is focused on the question: what are the research and major facilities required to develop the blanket/FW to a level which enables the design, construction and successful operation of a fusion DEMO? The principal challenges in the development of the blanket/FW are: (1) the Fusion Nuclear Environment – a multiple-field environment (neutrons, heat/particle fluxes, magnetic field, etc.) with high magnitudes and steep gradients and transients; (2) Nuclear Heating in a large volume with sharp gradients – the nuclear heating drives most blanket phenomena, but accurate simulation of this nuclear heating can be done only in a DT-plasma based facility; and (3) Complex Configuration with blanket/first wall/divertor inside the vacuum vessel – the consequence is low fault tolerance and long repair/replacement time. These blanket/FW development challenges result in critical consequences: (a) non-fusion facilities (laboratory experiments) need to be substantial to simulate multiple fields/multiple effects and must be accompanied by extensive modeling; (b) results from non-fusion facilities will be limited and will not fully resolve key technical issues. A DT-plasma based fusion nuclear science facility (FNSF) is required to perform “multiple effects” and “integrated” experiments in the fusion nuclear environment; and (c) the Reliability/Availability/Maintainability/Inspectability (RAMI) of fusion nuclear components is a major challenge and is one of the primary reasons

  19. Environmental considerations for alternative fusion reactor blankets

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.; Young, J.R.

    1975-01-01

    Comparisons of alternative fusion reactor blanket/coolant systems suggest that environmental considerations will enter strongly into selection of design and materials. Liquid blankets and coolants tend to maximize transport of radioactive corrosion products. Liquid lithium interacts strongly with tritium, minimizing permeation and escape of gaseous tritium in accidents. However, liquid lithium coolants tend to create large tritium inventories and have a large fire potential compared to flibe and solid blankets. Helium coolants minimize radiation transport, but do not have ability to bind the tritium in case of accidental releases. (auth)

  20. A Li-particulate blanket concept for ITER

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Cheng, E.T.; Creedon, R.L.

    1989-01-01

    The Li-particulate blanket design concept the authors proposed for the International Thermonuclear Experimental Reactor (ITER) uses a dilute suspension of fine solid breeder particles in a carrier gas as the combined coolant and lithium breeder stream. This blanket concept has a simple mechanical and hydraulic configuration, low inventory of bred tritium, and simple tritium extraction system. Existing technology can be used to implement the design for ITER. The concept has the potential to be a highly reliable shield and blanket design for ITER with relatively low development and capital costs

  1. How sustainable is the use of peat for commercial energy production?

    NARCIS (Netherlands)

    Schilstra, AJ

    The sustainability argument that more peat grows in Finland than is used does not hold. On designated peatlands, growth is about 85 times slower than peat use; growth elsewhere in Finland does not add to available resources. Claiming undisturbed peatlands as carbon sinks for sustainable peat use is

  2. How sustainable is the use of peat for commercial energy production?

    NARCIS (Netherlands)

    Schilstra, AJ

    2001-01-01

    The sustainability argument that more peat grows in Finland than is used does not hold. On designated peatlands, growth is about 85 times slower than peat use; growth elsewhere in Finland does not add to available resources. Claiming undisturbed peatlands as carbon sinks for sustainable peat use is

  3. Effects of peat-winning on the water environment at a sedge fen ecosystem

    International Nuclear Information System (INIS)

    Lundin, L.

    1997-06-01

    Peatlands are used in agriculture and forestry for vegetational growth and in peat-winning for soil improvement, horticulture production and as fuel. A prerequisite in peatland use is drainage, with influences on water conditions in the peatland and in its surroundings. Environmental effects from such peatland use have been investigated at a sedge fen in central Sweden. Groundwater, runoff, water chemistry and streamwater biology were studied during almost 14 years. This period started with a virgin undrained peatland, later being drained for forest production and after a period of seven years intensively drained for peat-winning and with peat harvesting going on for another seven year period with hydrological investigations. Results show a lowered groundwater level, increased runoff and both higher concentrations of most elements and higher leaching from the drained peatland. Biomass and number of individuals of the benthic fauna in streamwater also increased. 7 refs

  4. Study of the sorption properties of the peat for removal of heavy metals

    International Nuclear Information System (INIS)

    Hayrapetyan, S.S.; Gevorgyan, S.A.; Hayrapetyan, L.S.; Bareghamyan, S.F.; Pirumyan, G.P.

    2016-01-01

    The processes of sorption of several heavy metals on peat samples taken from basin of lake Sevan (near Vardenis Gegharkunik region of Armenia) were investigated. The peat samples were taken from different locations from 1 m depth. The sorption processes have been done in the static mode. The peat samples were used without any modification, i.e. the sorption properties of natural raw peat were studied. The studies were conducted on the basis of synthetic solution containing ions of these following metals - Ni, Co, As, U, Ba. The sorption properties of peat were estimated by ICP-MS. Thus, peat can be a very effective sorption medium for removal of heavy metals from water. Most of them are absorbed in the first minutes of peat exposure to aqueous solution. For the sorption of barium, uranium, arsenic peat exhibits very high sorption efficiency. For comparison, their relative sorption values about 10 times more than those of cobalt, nickel and zinc.

  5. Comparison of Shear Strength Properties for Undisturbed and Reconstituted Parit Nipah Peat, Johor

    Science.gov (United States)

    Azhar, A. T. S.; Norhaliza, W.; Ismail, B.; Abdullah, M. E.; Zakaria, M. N.

    2016-11-01

    Shear strength of soil is required to determine the soil stability and design the foundations. Peat is known as a soil with complex natural formations which also contributes problems to the researchers, developers, engineers and contractors in constructions and infrastructures. Most researchers conducted experiment and investigation of shear strength on peat using shear box test and simple shear test, but only a few had discovered the behavior of peat using triaxial consolidated undrained test. The aim of this paper is to determine the undrained shear strength properties of reconstituted peat and undisturbed peat of Parit Nipah, Johor for comparison purposes. All the reconstituted peat samples were formed with the size that passed opening sieve 3.35 mm and preconsolidation pressure at 100 kPa. The result of undrained shear strength of reconstituted peat was 21kPa for cohesion with the angle of friction, 41° compare to the undisturbed peat with cohesion 10 kPa and angle of friction, 16°. The undrained shear strength properties result obtained shows that the reconstituted peat has higher strength than undisturbed peat. For relationship deviator stress-strain, σd max and excess pore pressure, Δu, it shows that both of undisturbed and reconstituted gradually increased when σ’ increased, but at the end of the test, the values are slightly dropped. The physical properties of undisturbed and reconstituted peat were also investigated to correlate with the undrained shear strength results.

  6. Thermal properties of degraded lowland peat-moorsh soils

    Science.gov (United States)

    Gnatowski, Tomasz

    2016-04-01

    has decreased in a non-linear manner. Thermal parameters of the dry mass of the studied soils (Kdry, Cdry) were characterised by the mean value of approximately 0.11±0.028 W.m-1.K-1 and 0.781±0.220 MJ.m-3.K-1. The application of the correlation analysis showed that the most significant predictor of these properties of soils is the soil bulk density which, respectively explains: 54.6% and 67.1% of their variation. The increase of the accuracy in determining Kdry and Cdry was obtained by developing regression models, which apart from the bulk density also include the chemical properties of the peat soils. In the fully saturated soil the Ksat value ranged from 0.47 to 0.63 W.m-1.K-1, and the Csat varied from 3.200 to 3.995 MJ.m-3.K-1. The variation coefficients of these soil thermal features are at the level of approx. 5%. The obtained results allowed to conclude that the significant diversity of studied soils doesn't cause the significant differences in thermal soil parameters in fully saturated soils. The developed statistical relationships indicate that parameters Ksat and Csat were poorly correlated with saturated moisture content.

  7. Neutron dosimetry for the TFTR Lithium-Blanket-Module program

    International Nuclear Information System (INIS)

    Harker, Y.D.; Tsang, F.Y.; Caffrey, A.J.; Homeyer, W.G.; Engholm, B.A.

    1981-01-01

    The Tokamak Fusion Test Reactor (TFTR) Lithium Blanket Module (LBM) program is a first-of-a-kind neutronics experiment involving a prototypical fusion reactor blanket module with a distributed neutron source from the plasma of the TFTR at Princeton Plasma Physics Laboratory. The objectives of the LBM program are: (1) to test the capabilities of neutron transport codes when applied to fusion test reactor blanket conditions, and (2) to obtain tritium breeding performance data on a typical design concept of a fusion-reactor blanket. This paper addresses the issues relative to the measurement of neutron fields in the LBM, presents the results of preliminary design studies concerning neutron measurements and also presents the results of blanket mockup experiments performed at the Idaho National Engineering Laboratory

  8. Packed-fluidized-bed blanket concept for a thorium-fueled commercial tokamak hybrid reactor

    International Nuclear Information System (INIS)

    Chi, J.W.H.; Miller, J.W.; Karbowski, J.S.; Chapin, D.L.; Kelly, J.L.

    1980-09-01

    A preliminary design of a thorium blanket was carried out as a part of the Commercial Tokamak Hybrid Reactor (CTHR) study. A fixed fuel blanket concept was developed as the reference CTHR blanket with uranium carbide fuel and helium coolant. A fixed fuel blanket was initially evaluated for the thorium blanket study. Subsequently, a new type of hybrid blanket, a packed-fluidized bed (PFB), was conceived. The PFB blanket concept has a number of unique features that may solve some of the problems encountered in the design of tokamak hybrid reactor blankets. This report documents the thorium blanket study and describes the feasibility assessment of the PFB blanket concept

  9. Growing Tomato Plantlets on Various Mixtures of Peat and Sand or Peat and Perlite. Note 1

    Directory of Open Access Journals (Sweden)

    Antonia Patruno

    Full Text Available Given the considerable interest in use of substrates derived from various mixtures in the nursery sector and in light of the enormous variety of possibilities offered by this technique, in contrast with the still small number of researches dedicated to this theme, this study was set out to examine in-depth the growing of tomato plantlets on peat-based substrates. Two series of peat mixtures were produced, one with sand and the other with perlite, with a volume ratio of the other two components with respect to the peat of 1:0, 2.5:1, 1:1 and 1:2.5. Tomato seedlings were cultivated for 30 or 25 days in small perforated pots containing these mixtures. The irrigation was calculated by weighing each pot daily, measuring the water lost by evaporation-transpiration, then just past an established lower threshold value bringing the water back up to a defined upper threshold. Two water regimes were compared in the sand series and three in the perlite series.

  10. Desulphurization in peat-fired circulating and bubbling fluidized bed boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kouvo, P. [Imatran Voima Oy, Vantaa (Finland); Salmenoja, K. [Kvaerner Pulping Oy, Tampere (Finland)

    1997-12-31

    The new emission limit values for large combustion plants are under consideration both at the EU level and in Finland. Peat and wood are the only indigenous fuels of Finland. In 1995 appr. 8 % of electricity was produced with peat. The lower heating value of peat is around 10 MJ/kg. The moisture content varies between 35-55 % and sulphur content in dry solids between 0.15-0.35 %. The total peat power capacity of Finland in 1995 was 1400 MW. Because there was not enough information available about the desulphurization of the flue gases from peat-fired fluidized bed boilers, a group of Finnish companies and Ministry of Trade and Industry decided to carry out the full-scale desulphurisation study. In the project the desulphurization with limestone injection into the furnace of two types of peat-fired boilers were studied. The goal of the project was to investigate: what the technically and economically feasible emission level is by limestone injection in the fluidized bed combustion; how the limestone injection affects the other flue gas emissions and the fouling of the boiler and, what the economy of desulphurisation is. The tests were carried out at Kokkola and Kemi power plants in Finland. At Kokkola (108 MW{sub f}) circulating fluidized bed boiler, the emission limit of 200 mg/m{sup 3}n was leached at a Ca/S-molar ratio of appr. 10, with limestone containing 92 % of calcium carbonate, CaCO{sub 3}. At Kemi (267 MW{sub f}) bubbling fluidized bed boiler, the emission limit of 280 mg/m{sup 3}n with limestone containing appr. 95 % of CaCO{sub 3} was reached at a Ca/S-molar ratio of appr. 7.0. Emissions of NO{sub x}, N{sub 2}O, NH{sub 3} and dust after the ESP were not elevated due to the limestone feed. At the Kokkola power plant the NO{sub x} emissions varied from 300 to 400 mg/m{sup 3}n, and, at the Kemi power station the NO{sub x} emissions were around 200 mg/m{sup 3}n. The fouling of the Kemi boiler was found to be significant in the scheduled outage after the test

  11. A Feasible DEMO Blanket Concept Based on Water Cooled Solid Breeder

    Energy Technology Data Exchange (ETDEWEB)

    Someya, Y.; Tobita, K.; Utoh, H.; Hoshino, K.; Asakura, N.; Nakamura, M.; Tanigawa, H.; Mikio, E.; Tanigawa, H.; Nakamichi, M.; Hoshino, T., E-mail: someya.yoji@jaea.go.jp [Japan Atomic Energy Agency, Rokkasho (Japan)

    2012-09-15

    Full text: JAEA has conducted the conceptual design study of blanket for a fusion DEMO reactor SlimCS. Considering DEMO specific requirements, we place emphasis on a blanket concept with durability to severe irradiation, ease of fabrication for mass production, operation temperature of blanket materials, and maintainability using remote handling equipment. This paper present a promising concept satisfying these requirements, which is characterized by minimized welding lines near the front, a simplified blanket interior consisting of cooling tubes and a mixed pebble bed of breeder and neutron multiplier, and approximately the same outlet temperature for all blanket modules. Neutronics calculation indicated that the blanket satisfies a self-sufficient production of tritium. An important finding is that little decrease is seen in tritium breeding ratio even when the gap between neighboring blanket modules is as wide as 0.03 m. This means that blanket modules can be arranged with such a significant clearance gap without sacrifice of tritium production, which will facilitate the access of remote handling equipment for replacement of the blanket modules and improve the access of diagnostics. (author)

  12. Optimizing outlays for transporting agricultural peat to the consumers

    Energy Technology Data Exchange (ETDEWEB)

    Dem' yanov, Ye S; Prisadkov, V I; Silant' yeza, G P

    1979-01-01

    An economic-mathematical model is described for supplying the consumers with agricultural peat and the corresponding computer program. Certain results are presented of calculating the optimal plans for transporting peat from the enterprises of the association Kalinintorf.

  13. Peat subsidence and its practical implications: a case study in Malaysia

    NARCIS (Netherlands)

    Wösten, J.H.M.; Ismail, A.B.; Wijk, van A.L.M.

    1997-01-01

    Due to pressure for land, substantial areas of peat swamps in South-East Asia have been and presently are being reclaimed for agriculture or for other land use. As soon as peat swamps are drained, the irreversible process of subsidence starts, which can only be stopped by waterlogging the peat

  14. Imploding-liner reactor nucleonic studies: the LINUS blanket

    International Nuclear Information System (INIS)

    Dudziak, D.J.

    1977-09-01

    Scoping nucleonic studies have been performed for a small imploding-liner fusion reactor concept. Tritium breeding ratio and time-dependent energy deposition rates were the primary parameters of interest in the study. Alloys of Pb and LiPb were considered for the liquid liner (blanket), and tritium breeding was found to be more than adequate with blankets less than 1 m thick. However, neutron leakages into the solid cylinder block surrounding the liquid liner are generally quite high, so considerable effort was concentrated on minimizing these values. Time-dependent calculations reveal that 89% of the energy is deposited in the blanket within 2 μs. Thus, LINUS's blanket should remain intact for the requisite neutron and gamma-ray lifetimes

  15. Np-237 in peat and lichen in Finland

    DEFF Research Database (Denmark)

    Salminen, S.; Paatero, J.; Roos, Per

    2009-01-01

    Activity concentrations of 237Np in peat and lichen samples in Finland were determined and contributions from nuclear weapons testing in 1950–1960s and the Chernobyl accident were estimated. 237Np was determined with ICP-MS using 235Np as a tracer. Activity concentrations of 237Np in peat samples...

  16. Temperature-driven adaptation of the bacterial community in peat measured by using thymidine and leucine incorporation.

    Science.gov (United States)

    Ranneklev, S B; Bååth, E

    2001-03-01

    temperature adaptation indices over time for peat samples incubated at 55 degrees C 3 or 11 days before incubation at 25 degrees C. Thus, different levels of bacterial activity did not affect the temperature-driven adaptation of the bacterial community.

  17. Fusion-reactor blanket-material safety-compatibility studies

    International Nuclear Information System (INIS)

    Jeppson, D.W.; Muhlestein, L.D.; Keough, R.F.; Cohen, S.

    1982-11-01

    Blanket material selection for fusion reactors is strongly influenced by the desire to minimize safety and environmental concerns. Blanket material safety compatibility studies are being conducted to identify and characterize blanket-coolant-material interactions under postulated reactor accident conditions. Recently completed scoping compatibility tests indicate that : (1) ternary oxides (LiAlO 2 , Li 2 ZrO 3 , Li 2 SiO 3 , Li 4 SiO 4 and LiTiO 3 ) at postulated blanket operating temperatures are compatible with water coolant, while liquid lithium and Li 7 Pb 2 alloy reactions with water generate heat, aerosol and hydrogen; (2) lithium oxide and Li 17 Pb 83 alloy react mildly with water requiring special precautions to control hydrogen release; (3) liquid lithium reacts substantially, while Li 17 Pb 83 alloy reacts mildly with concrete to produce hydrogen; and (4) liquid lithium-air reactions present some major safety concerns

  18. New concepts for controlled fusion reactor blanket design

    International Nuclear Information System (INIS)

    Conn, R.W.; Kulcinski, G.L.; Avci, H.; El-Maghrabi, M.

    1975-01-01

    Several new concepts for fusion reactor blanket design based on the idea of shifting, or tailoring, the neutron spectrum incident on the first structural wall are presented. The spectral shifter is a nonstructural element which can be made of graphite, silicon carbide, or three dimensionally woven carbon fibers (and containing other materials as appropriate) placed between the neutron source and the first structural wall. The softened neutron spectrum incident on the structural components leads to lower gas production and atom displacement rates than in more standard fusion blanket designs. In turn, this results in longer anticipated lifetimes for the structural materials and can significantly reduce radioactivity and afterheat levels. In addition, the neutron spectrum in the first structural wall can be made to approach the flux shape in fast breeder reactors. Such spectral softening means that existing radiation facilities may be more profitably used to provide relevant materials radiation damage data for the structural materials in these fusion blanket designs. This general class of blanket concepts are referred to as internal spectral shifter and energy converter, or ISSEC concepts. These specific design concepts fall into three main categories: ISSEC/EB concepts based on utilizing existing designs which breed tritium behind the first structural wall; ISSEC/IB concepts based on breeding tritium inside the first vacuum wall; and ISSEC/Bu concepts based on using boron, carbon, and perhaps, beryllium to obtain an energy multiplier and converter design that does not attempt to breed tritium or utilize lithium. The detailed analyses relate specifically to the nuclear performance of ISSEC systems and to a discussion of materials radiation damage problems in the structural material.(U.S.)

  19. Remote handling assessment of attachment concepts for DEMO blanket segments

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Daniel, E-mail: daniel.iglesias@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Bastow, Roger; Cooper, Dave; Crowe, Robert; Middleton-Gear, Dave [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Sibois, Romain [VTT, Technical Research Centre of Finland, Industrial Systems, ROViR, Tampere (Finland); Carloni, Dario [Institute of Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (KIT) (Germany); Vizvary, Zsolt; Crofts, Oliver [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Harman, Jon [EFDA Close Support Unit Garching, Boltzmannstaße 2, D-85748 Garching bei München (Germany); Loving, Antony [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2015-10-15

    Highlights: • Challenges are identified for the remote handling of blanket segments’ attachments. • Two attachment design approaches are assessed for remote handling (RH) feasibility. • An alternative is proposed, which potentially simplifies and speeds-up RH operations. • Up to three different assemblies are proposed for the remote handling of the attachments. • Proposed integrated design of upper port is compatible with the attachment systems. - Abstract: The replacement strategy of the massive Multi-Module Blanket Segments (MMS) is a key driver in the design of several DEMO systems. These include the blankets themselves, the vacuum vessel (VV) and its ports and the Remote Maintenance System (RMS). Common challenges to any blanket attachment system have been identified, such as the need for applying a preload to the MMS manifold, the effects of the decay heat and several uncertainties related to permanent deformations when removing the blanket segments after service. The WP12 kinematics of the MMS in-vessel transportation was adapted to the requirements of each of the supports during 2013 and 2014 design activities. The RM equipment envisaged for handling attachments and earth connections may be composed of up to three different assemblies. An In-Vessel Mover at the divertor level handles the lower support and earth bonding, and could stabilize the MMS during transportation. A Shield Plug crane with a 6 DoF manipulator operates the upper attachment and earth straps. And a Vertical Maintenance Crane is responsible for the in-vessel MMS transportation and can handle the removable upper support pins. A final proposal is presented which can potentially reduce the number of required systems, at the same time that speeds-up the RMS global operations.

  20. European DEMO BOT solid breeder blanket

    International Nuclear Information System (INIS)

    Dalle Donne, M.

    1994-11-01

    The BOT (Breeder Outside Tube) Solid Breeder Blanket for a fusion DEMO reactor is presented. This is one of the four blanket concepts under development in the frame of the European fusion technology program with the aim to select in 1995 the two most promising ones for further development. In the paper the reference blanket design and external loops are described as well as the results of the theoretical and experimental work in the fields of neutronics, thermohydraulics, mechanical stresses, tritium control and extraction, development and irradiation of the ceramic breeder material, beryllium development, ferromagnetic forces caused by disruptions, safety and reliability. An outlook is given on the remaining open questions and on the required R and D program. (orig.) [de

  1. Aid policy for peat from the EU's standpoint

    International Nuclear Information System (INIS)

    Alanen, J.; Suvanto-Luomala, S.; Aeimae, K.

    2002-10-01

    The study analyses the restrictions that may be imposed by the European Union on our national taxation schemes supporting the energy use of peat. These restrictions would mainly relate to the EU and international climate policy, which may change the attitudes towards the energy use of peat. The taxation arrangements studied concern the refunds of the electricity tax granted to small peat-fired power plants and the tax on peat, which compared especially with coal, is light in heat production. The study aims to find out whether the arrangements included State aid prohibited by the European Community or whether they gave rise to prohibited tax discrimination of other Member States' energy products. It was concluded that the objectives of the Community, particularly the regional security of energy supply, promotion of combined electricity and heat production, and employment, favour the energy use of peat rather than oppose to it. As for the aid to small power plants, it can be considered that the grounds for obtaining an exemption from the EC State aid prohibition exist, because the benefits of the aid referred to are more important than the disadvantages brought by it for undistorted trade and competition. This situation cannot be expected to change in the near future, either, e.g. as a result of the climate policy. As regards heat production, peat taxation cannot be considered to include State aid or to lead to discrimination against exported fuels like coal. This is essentially based on the taxation sovereignty of Member States and the related right to enhance national goals by means of taxation. The current energy tax regulation by the Community or the Commission's Proposal for an Energy Tax Directive do not seem to pose any obstacles to continuing Finland's present energy taxation policy. (orig.)

  2. Transient peat properties in two pond-peatland complexes in the sub-humid Western Boreal Plain, Canada

    Directory of Open Access Journals (Sweden)

    R.M. Petrone

    2008-03-01

    Full Text Available In the Canadian Western Boreal Plain (WBP, wetlands (ponds and peatlands comprise up to 50% of the landscape and represent unique habitat where summer precipitation is often outpaced by evapotranspiration and hillslope groundwater position does not follow topography. In this sub-humid location, groundwater fluxes and stores in riparian peatlands influence pond water levels and root zone moisture sources for forested uplands. To accurately describe the transport and retention of water in peat, it is important to consider peat subsidence. This paper quantifies the amount and effect of seasonal subsidence in a riparian peatland in the Utikuma Lake region in north-central Alberta, Canada. Results demonstrate that the deep and poorly decomposed peat deposits are resistant to compression, and that thick (and persistent ground frost hinders pore collapse (shrinkage above the water table until late summer when the ground has thawed. Even then, subsidence is still limited to the top 50 cm and is not closely related to changes in peatland water table or pond water level. Thus the water balance of these ponds and riparian areas appears to be less sensitive to peat volume changes than it is to the persistence of a substantial frost layer well into the snow-free period.

  3. Geophysical surveying in the Sacramento Delta for earthquake hazard assessment and measurement of peat thickness

    Science.gov (United States)

    Craig, M. S.; Kundariya, N.; Hayashi, K.; Srinivas, A.; Burnham, M.; Oikawa, P.

    2017-12-01

    Near surface geophysical surveys were conducted in the Sacramento-San Joaquin Delta for earthquake hazard assessment and to provide estimates of peat thickness for use in carbon models. Delta islands have experienced 3-8 meters of subsidence during the past century due to oxidation and compaction of peat. Projected sea level rise over the next century will contribute to an ongoing landward shift of the freshwater-saltwater interface, and increase the risk of flooding due to levee failure or overtopping. Seismic shear wave velocity (VS) was measured in the upper 30 meters to determine Uniform Building Code (UBC)/ National Earthquake Hazard Reduction Program (NEHRP) site class. Both seismic and ground penetrating radar (GPR) methods were employed to estimate peat thickness. Seismic surface wave surveys were conducted at eight sites on three islands and GPR surveys were conducted at two of the sites. Combined with sites surveyed in 2015, the new work brings the total number of sites surveyed in the Delta to twenty.Soil boreholes were made at several locations using a hand auger, and peat thickness ranged from 2.1 to 5.5 meters. Seismic surveys were conducted using the multichannel analysis of surface wave (MASW) method and the microtremor array method (MAM). On Bouldin Island, VS of the surficial peat layer was 32 m/s at a site with pure peat and 63 m/s at a site peat with higher clay and silt content. Velocities at these sites reached a similar value, about 125 m/s, at a depth of 10 m. GPR surveys were performed at two sites on Sherman Island using 100 MHz antennas, and indicated the base of the peat layer at a depth of about 4 meters, consistent with nearby auger holes.The results of this work include VS depth profiles and UBC/NEHRP site classifications. Seismic and GPR methods may be used in a complementary fashion to estimate peat thickness. The seismic surface wave method is a relatively robust method and more effective than GPR in many areas with high clay

  4. Beryllium R and D for blanket application

    Energy Technology Data Exchange (ETDEWEB)

    Dalle Donne, M.; Scaffidi-Argentina, F. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik; Longhurst, G.R. [Idaho National Engineering Lab., Idaho Falls (United States); Kawamura, H. [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-10-01

    The paper describes the main problems and the R and D for the beryllium to be used as neutron multiplier in blankets. As the four ITER partners propose to use beryllium in the form of pebbles for their DEMO relevant blankets (only the Russians consider the porous beryllium option as an alternative) and the ITER breeding blanket will use beryllium pebbles as well, the paper is mainly based on beryllium pebbles. Also the work on the chemical reactivity of fully dense and porous beryllium in contact with water steam is described, due to the safety importance of this point. (orig.) 29 refs.

  5. Beryllium R and D for blanket application

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Scaffidi-Argentina, F.; Kawamura, H.

    1998-01-01

    The paper describes the main problems and the R and D for the beryllium to be used as neutron multiplier in blankets. As the four ITER partners propose to use beryllium in the form of pebbles for their DEMO relevant blankets (only the Russians consider the porous beryllium option as an alternative) and the ITER breeding blanket will use beryllium pebbles as well, the paper is mainly based on beryllium pebbles. Also the work on the chemical reactivity of fully dense and porous beryllium in contact with water steam is described, due to the safety importance of this point. (orig.)

  6. Mechanical and thermal design of hybrid blankets

    International Nuclear Information System (INIS)

    Schultz, K.R.

    1978-01-01

    The thermal and mechanical aspects of hybrid reactor blanket design considerations are discussed. This paper is intended as a companion to that of J. D. Lee of Lawrence Livermore Laboratory on the nuclear aspects of hybrid reactor blanket design. The major design characteristics of hybrid reactor blankets are discussed with emphasis on the areas of difference between hybrid reactors and standard fusion or fission reactors. Specific examples are used to illustrate the design tradeoffs and choices that must be made in hybrid reactor design. These examples are drawn from the work on the Mirror Hybrid Reactor

  7. Blanket safety by GEMSAFE methodology

    International Nuclear Information System (INIS)

    Sawada, Tetsuo; Saito, Masaki

    2001-01-01

    General Methodology of Safety Analysis and Evaluation for Fusion Energy Systems (GEMSAFE) has been applied to a number of fusion system designs, such as R-tokamak, Fusion Experimental Reactor (FER), and the International Thermonuclear Experimental Reactor (ITER) designs in the both stages of Conceptual Design Activities (CDA) and Engineering Design Activities (EDA). Though the major objective of GEMSAFE is to reasonably select design basis events (DBEs) it is also useful to elucidate related safety functions as well as requirements to ensure its safety. In this paper, we apply the methodology to fusion systems with future tritium breeding blankets and make clear which points of the system should be of concern from safety ensuring point of view. In this context, we have obtained five DBEs that are related to the blanket system. We have also clarified the safety functions required to prevent accident propagations initiated by those blanket-specific DBEs. The outline of the methodology is also reviewed. (author)

  8. The effects of salinization on aerobic and anaerobic decomposition and mineralization in peat meadows : the roles of peat type and land use

    NARCIS (Netherlands)

    Brouns, Karlijn; Verhoeven, Jos T A; Hefting, Mariet M

    2014-01-01

    Peat soils comprise a large part of the western and northern Netherlands. Drainage for agriculture has caused increased soil aeration which has stimulated decomposition and, hence, soil subsidence, currently amounting to 1-2 cm/yr. River water is supplied to these peat areas in summer to prevent

  9. Control of Sound Radiation and Reflection With Advanced Smart Foam Blankets

    National Research Council Canada - National Science Library

    Fuller, Chris

    2003-01-01

    .... The past few years of the project have demonstrated the high potential of using smart foam blankets for efficiently reducing the interior sound levels in the payloads of launch vehicles in the low...

  10. INTOR first wall/blanket/shield activity

    International Nuclear Information System (INIS)

    Gohar, Y.; Billone, M.C.; Cha, Y.S.; Finn, P.A.; Hassanein, A.M.; Liu, Y.Y.; Majumdar, S.; Picologlou, B.F.; Smith, D.L.

    1986-01-01

    The main emphasis of the INTOR first wall/blanket/shield (FWBS) during this period has been upon the tritium breeding issues. The objective is to develop a FWBS concept which produces the tritium requirement for INTOR operation and uses a small fraction of the first wall surface area. The FWBS is constrained by the dimensions of the reference design and the protection criteria required for different reactor components. The blanket extrapolation to commercial power reactor conditions and the proper temperature for power extraction have been sacrificed to achieve the highest possible local tritium breeding ratio (TBR). In addition, several other factors that have been considered in the blanket survey study include safety, reliability, lifetime fluence, number of burn cycles, simplicity, cost, and development issues. The implications of different tritium supply scenarios were discussed from the cost and availability for INTOR conditions. A wide variety of blanket options was explored in a preliminary way to determine feasibility and to see if they can satisfy the INTOR conditions. This survey and related issues are summarized in this report. Also discussed are material design requirements, thermal hydraulic considerations, structure analyses, tritium permeation through the first wall into the coolant, and tritium inventory

  11. ITER driver blanket, European Community design

    International Nuclear Information System (INIS)

    Simbolotti, G.; Zampaglione, V.; Ferrari, M.; Gallina, M.; Mazzone, G.; Nardi, C.; Petrizzi, L.; Rado, V.; Violante, V.; Daenner, W.; Lorenzetto, P.; Gierszewski, P.; Grattarola, M.; Rosatelli, F.; Secolo, F.; Zacchia, F.; Caira, M.; Sorabella, L.

    1993-01-01

    Depending on the final decision on the operation time of ITER (International Thermonuclear Experimental Reactor), the Driver Blanket might become a basic component of the machine with the main function of producing a significant fraction (close to 0.8) of the tritium required for the ITER operation, the remaining fraction being available from external supplies. The Driver Blanket is not required to provide reactor relevant performance in terms of tritium self-sufficiency. However, reactor relevant reliability and safety are mandatory requirements for this component in order not to significantly afftect the overall plant availability and to allow the ITER experimental program to be safely and successfully carried out. With the framework of the ITER Conceptual Design Activities (CDA, 1988-1990), a conceptual design of the ITER Driver Blanket has been carried out by ENEA Fusion Dept., in collaboration with ANSALDO S.p.A. and SRS S.r.l., and in close consultation with the NET Team and CFFTP (Canadian Fusion Fuels Technology Project). Such a design has been selected as EC (European Community) reference design for the ITER Driver Blanket. The status of the design at the end of CDA is reported in the present paper. (orig.)

  12. Heterotrophic respiration in drained tropical peat temperatures influenced by shading gradient

    Science.gov (United States)

    Jauhiainen, Jyrki; Kerojoki, Otto; Silvennoinen, Hanna; Limin, Suwido; Vasander, Harri

    2015-04-01

    Lowland peatlands in Southeast Asia constitute a highly concentrated carbon (C) pool of global significance. These peatlands have formed over periods of several millennia by forest vegetation tolerant to flooding and poor substrates. Uncontrollable drainage and reoccurring wild fires in lack of management after removal of forest cover has impaired the C-storing functions in large reclaimed areas. Intergovernmental Panel on Climate Change (IPCC) reporting sees drained tropical organic soils as one of the largest greenhouse gas emissions releasing terrestrial systems. Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, which increases the amount of solar radiation reaching the peat surface. We studied heterotrophic carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes in tropical peat in conditions, where; (i) peat temperatures were modified by artificial shading (no shade, 28%, 51% and 90% from the full sun exposure), (ii) root respiration was minimized, (iii) nutrient availability for peat decomposer community was changed (NPK fertilization of 0 and 313 kg ha-1). The experiment was repeated at two over 20 years ago drained fallow agricultural- and degraded sites in Central Kalimantan, Indonesia. Enhanced shading created a lasting decrease in peat temperatures, and decreased diurnal temperature fluctuations, in comparison to less shaded plots. The largest peat temperature difference was between the unshaded and 90% shaded peat surface, where the average temperatures within the topmost 50-cm peat profile differed 3 °C, and diurnal temperatures at 5 cm depth varied up to 4.2 °C in the unshaded and 0.4 °C in the 90% shaded conditions. Highest impacts on the heterotrophic CO2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO2 emission average on the unfertilised plots and a 66% lower emission average on the fertilised plots. Correlation

  13. Sterilization of peat by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Parker, F E; Vincent, J M [New South Wales Univ., Kensington (Australia). School of Microbiology

    1981-01-01

    The effect of gamma-radiation on the survival of microorganisms has been quantified for the natural population of two types of peat. Data for several microbial types have been separately determined by regular plating and by indirect statistical probability estimates including, a wholly enclosed 'inverted-bottle' technique for higher dose levels to exclude any possibility of post-treatment contamination. The most persistent microorganisms at intermediate dosage (2.5-3.5 Mrad) were commonly a micrococcus (which closely resembled Micrococcus radiodurans) arthrobacter-like rods, myxobacteria and amoeboid forms. The persistent organisms all survived because of high resistance to ..gamma..-irradiation, not because of high initial numbers. The most numerous true bacteria (including spore-formers), actinomycetes, filamentous fungi and yeasts were all readily destroyed. Although the safety margin with the commercially recommended dose of 5 Mrad is low for some of the more resistant organisms, no change is justified at this stage since the organisms most likely to survive such a dose do not seem to seriously affect the subsequent growth and survival of rhizobia. Moreover there would be some risk of radiation-induced peat toxicity if higher doses were applied and some post-irradiation contamination will be difficult to avoid in commercial production.

  14. Effects of peat-winning on the water environment at a sedge fen ecosystem

    International Nuclear Information System (INIS)

    Lundin, L.

    1996-03-01

    Peatlands are used in agriculture and forestry for vegetational growth and in peat-winning for soil improvement, horticulture production and as fuel. A prerequisite in peatland use is drainage, with influences on water conditions in the peatland and its surroundings. Environmental effects from such peatland use have been investigated at a sedge fen in central Sweden. Groundwater, runoff, water chemistry and stream water biology were studied during almost 14 years. This period started with a virgin undrained peatland, later being drained for forest production and after a period of seven years intensively drained for peat-winning and with peat harvesting going on for another seven years period with hydrological investigations. Results show a lowered groundwater level, increased runoff and both higher concentrations of most elements and higher leaching from the drained peatland. Biomass and number of individuals of the benthic fauna in stream water also increased. 7 refs, 7 figs, 2 tabs

  15. Peat Deposits at Bijoynagar Upazila, Brahmanbaria District, Bangladesh : A Potential Local Source of Energy

    Directory of Open Access Journals (Sweden)

    Md. Nazwanul Haque

    2013-12-01

    Full Text Available Bangladesh with about 160 million people in land of 147,570 square km which is one of the most densely populated countries in the world. With the increase of population and diversifying of economic activities, Bangladesh has become an energy hunger country. Presently, 80% peoples depend on non commercial energy sources living in the rural area. Peat exploration at Bijoynagar Upazila, Brahmanbaria district. Bangladesh has been carried out for reserve estimation and its economic aspect evaluation. Total peat exploration area is about 4000 hectare. In explored area, nine peat bearing locations are identified in which peat deposits are observed from 0.152 to 3.0 meters below the surface. Total reserves are about 32.61 million tons in wet condition and 13.044 million tons in dry conditions. The peat is grayish brown to grayish black, fibrous, less to medium compacted and water content is about 60-80 % in wet condition. Chemical analyses of the peat shows that fixed carbon content is 15-25 %, Sulfur is 0.1 to 0.8 % and calorific value of the peat is 3000-7000 BTU. The peat of the area is medium to good quality. The peat may be extracted by open peat mining because of its surface to near surface position. This peat can be conveniently used for small industrial and domestic purpose as briquette and compressed tablet form to meet the growing energy demand of the area. But most of the people of Bijoynagar area live on agriculture. So, peat extraction and related geo-environmental degradation may change living style of the people. Proper land use planning, environmental management and policy should be taken before peat extraction.

  16. Analysis and optimization of minor actinides transmutation blankets with regards to neutron and gamma sources

    International Nuclear Information System (INIS)

    Kooyman, T.; Buiron, L.; Rimpault, G.

    2017-01-01

    Heterogeneous loading of minor actinides in radial blankets is a potential solution to implement minor actinides transmutation in fast reactors. However, to compensate for the lower flux level experienced by the blankets, the fraction of minor actinides to be loaded in the blankets must be increased to maintain acceptable performances. This severely increases the decay heat and neutron source of the blanket assemblies, both before and after irradiation, by more than an order of magnitude in the case of neutron source for instance. We propose here to implement an optimization methodology of the blankets design with regards to various parameters such as the local spectrum or the mass to be loaded, with the objective of minimizing the final neutron source of the spent assembly while maximizing the transmutation performances of the blankets. In a first stage, an analysis of the various contributors to long- and short-term neutron and gamma source is carried out whereas in a second stage, relevant estimators are designed for use in the effective optimization process, which is done in the last step. A comparison with core calculations is finally done for completeness and validation purposes. It is found that the use of a moderated spectrum in the blankets can be beneficial in terms of final neutron and gamma source without impacting minor actinides transmutation performances compared to more energetic spectrum that could be achieved using metallic fuel for instance. It is also confirmed that, if possible, the use of hydrides as moderating material in the blankets is a promising option to limit the total minor actinides inventory in the fuel cycle. If not, it appears that focus should be put upon an increased residence time for the blankets rather than an increase in the acceptable neutron source for handling and reprocessing. (authors)

  17. Analysis and optimization of minor actinides transmutation blankets with regards to neutron and gamma sources

    Directory of Open Access Journals (Sweden)

    Kooyman Timothée

    2017-01-01

    Full Text Available Heterogeneous loading of minor actinides in radial blankets is a potential solution to implement minor actinides transmutation in fast reactors. However, to compensate for the lower flux level experienced by the blankets, the fraction of minor actinides to be loaded in the blankets must be increased to maintain acceptable performances. This severely increases the decay heat and neutron source of the blanket assemblies, both before and after irradiation, by more than an order of magnitude in the case of neutron source for instance. We propose here to implement an optimization methodology of the blankets design with regards to various parameters such as the local spectrum or the mass to be loaded, with the objective of minimizing the final neutron source of the spent assembly while maximizing the transmutation performances of the blankets. In a first stage, an analysis of the various contributors to long- and short-term neutron and gamma source is carried out whereas in a second stage, relevant estimators are designed for use in the effective optimization process, which is done in the last step. A comparison with core calculations is finally done for completeness and validation purposes. It is found that the use of a moderated spectrum in the blankets can be beneficial in terms of final neutron and gamma source without impacting minor actinides transmutation performances compared to more energetic spectrum that could be achieved using metallic fuel for instance. It is also confirmed that, if possible, the use of hydrides as moderating material in the blankets is a promising option to limit the total minor actinides inventory in the fuel cycle. If not, it appears that focus should be put upon an increased residence time for the blankets rather than an increase in the acceptable neutron source for handling and reprocessing.

  18. Analysis and optimization of minor actinides transmutation blankets with regards to neutron and gamma sources

    Science.gov (United States)

    Kooymana, Timothée; Buiron, Laurent; Rimpault, Gérald

    2017-09-01

    Heterogeneous loading of minor actinides in radial blankets is a potential solution to implement minor actinides transmutation in fast reactors. However, to compensate for the lower flux level experienced by the blankets, the fraction of minor actinides to be loaded in the blankets must be increased to maintain acceptable performances. This severely increases the decay heat and neutron source of the blanket assemblies, both before and after irradiation, by more than an order of magnitude in the case of neutron source for instance. We propose here to implement an optimization methodology of the blankets design with regards to various parameters such as the local spectrum or the mass to be loaded, with the objective of minimizing the final neutron source of the spent assembly while maximizing the transmutation performances of the blankets. In a first stage, an analysis of the various contributors to long and short term neutron and gamma source is carried out while in a second stage, relevant estimators are designed for use in the effective optimization process, which is done in the last step. A comparison with core calculations is finally done for completeness and validation purposes. It is found that the use of a moderated spectrum in the blankets can be beneficial in terms of final neutron and gamma source without impacting minor actinides transmutation performances compared to more energetic spectrum that could be achieved using metallic fuel for instance. It is also confirmed that, if possible, the use of hydrides as moderating material in the blankets is a promising option to limit the total minor actinides inventory in the fuel cycle. If not, it appears that focus should be put upon an increased residence time for the blankets rather than an increase in the acceptable neutron source for handling and reprocessing.

  19. Summary of the target-blanket breakout group

    Energy Technology Data Exchange (ETDEWEB)

    Capiello, M.; Bell, C. [Los Alamos National Laboratory, NM (United States); Barthold, W.

    1995-10-01

    This breakout group discussed a number of topics and issues pertaining to target and blanket concepts for accelerator-driven systems. This major component area is one marked by a broad spectrum of technical approaches. It is therefore less defined than other major component areas such as the accelerator and is at an earlier stage of technical needs and task specification. The working group did reach a number of general conclusions and recommendations that are summarized. The Conference and the Target/Blanket Breakout Group provided a first opportunity for people working on a variety of missions and concepts to get together and exchange information. A number of subcritical systems applicable for a spectrum of missions were proposed at the Conference and discussed in the Breakout Group. Missions included plutonium disposition, energy production, waste destruction, isotope production, and neutron scattering. The Target/Blanket Breakout Group also defined areas where parameters and data should be addressed as target/blanket design activities become more detailed and sophisticated.

  20. Fusion blanket testing in MFTF-α + T

    International Nuclear Information System (INIS)

    Kleefeldt, K.

    1985-01-01

    The Mirror Fusion Test Facility-α + T (MFTF-α + T) is an upgraded version of the current MFTF-B test facility at Lawrence Livermore National Laboratory, and is designed for near-term fusion-technology-integrated tests at a neutron flux of 2 MW/m 2 . Currently, the fusion community is screening blanket and related issues to determine which ones can be addressed using MFTF-α + T. In this work, the minimum testing needs to address these issues are identified for the liquid-metal-cooled blanket and the solid-breeder blanket. Based on the testing needs and on the MFTF-α + T capability, a test plan is proposed for three options; each option covers a six to seven year testing phase. The options reflect the unresolved question of whether to place the research and development (R and D) emphasis on liquid-metal or solid-breeder blankets. In each case, most of the issues discussed can be addressed to a reasonable extent in MFTF-α+T

  1. Fuel peat utilization in Finland: resource use and emissions

    International Nuclear Information System (INIS)

    Leijting, J.

    1999-01-01

    The aim of the study was to inventorize the emissions and other stressors caused by fuel peat use in Finland. The life cycle approach was used to organise and compile the burdens associated with the fuel peat utilisation sector in the years 1994 and 1995. Fuel peat accounts for about 6.5 % of the total primary energy production in Finland. The study showed that most emissions out into the air occur during combustion of peat in energy plants. The emissions account for about 13 - 14 % of the CO 2 emissions released by fossil fuel utilisation in Finland, for 12 % of the SO 2 for 8 % of the N 2 O and approximately 4 % of the NOR emissions released by anthropogenic sources in Finland. Phosphorus releases into waters contributes for about 0.2 % while nitrogen releases account for 0.3 % in the total anthropogenic discharge in Finland. (orig.) 88 refs

  2. Pulsed activation analyses of the ITER blanket design options considered in the blanket trade-off study

    International Nuclear Information System (INIS)

    Wang, Q.; Henderson, D.L.

    1995-01-01

    Pulsed activation calculations have been performed on two blanket options considered as part of the ITER home team blanket trade-off study. The objective was to compare the activity, afterheat and waste disposal rating (WDR) results of a composite blanket-shield design for the continuous operation approximation to a pulsed operation case to determine whether the differences are at most the duty factor as predicted by the two nuclide chain model. Up to a cooling period of 100 years, the pulsed activity and afterheat values were below the continuous oepration results and well within (except for one afterheat value) the maximum deviation predicted by the two nuclide chain model. No differences in the WDR values were noted as they are, to a large extent, based on long-lived nuclides which are insensitive to short-term changes in the operation history. (orig.)

  3. Guidelines for the environmental protection in peat mining; Turvetuotannon ympaeristoensuojeluohje

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-15

    The objective of these guidelines is to accelerate environmental protection in peat mining and to reduce the harmful effects caused by its related activities. The guidelines promote achievement of environmental objectives set both in legislation and government programmes through uniform practices and interpretations. The guidelines are based on current valid legislation. The guidelines provide up-to-date information on best practices in peat mining, especially in water protection but also in reducing noise and dust. They are intended to ease the work of both peat producers and the licensing and controlling authorities. The guidelines are not legally binding and must be applied on case-by-case basis. The current guidelines replace the 'Guidelines for environmental protection in peat mining' given in 2008. (orig.)

  4. Foam concrete of increased strength with the thermomodified peat additives

    Science.gov (United States)

    Kudyakov, A. I.; Kopanitsa, N. O.; Sarkisov, Ju S.; Kasatkina, A. V.; Prischepa, I. A.

    2015-01-01

    The paper presents the results of research of foam concrete with thermomodified peat additives. The aim of the research was to study the effect of modifying additives on cement stone and foam concrete properties. Peat additives are prepared by heat treatment of peat at 600 °C. Two approaches of obtaining additives are examined: in condition of open air access (TMT-600) and in condition of limited air access (TMT-600-k). Compressive strength of a cement stone with modifiers found to be increased by 28.9 - 65.2%. Introducing peat modifiers into foam concrete mix leads to increase of compressive strength by 44-57% at 28- day age and heat conductivity of foam concrete decreases by 0.089 W/(m·°C).

  5. Axial blanket enrichment optimization of the NPP Krsko fuel

    International Nuclear Information System (INIS)

    Kromar, M.; Kurincic, B.

    2001-01-01

    In this paper optimal axial blanket enrichment of the NPP Krsko fuel is investigated. Since the optimization is dictated by economic categories that can significantly vary in time, two step approach is applied. In the first step simple relationship between the equivalent change in enrichment of axial blankets and central fuel region is established. The relationship is afterwards processed with economic criteria and constraints to obtain optimal axial blanket enrichment. In the analysis realistic NPP Krsko conditions are considered. Except for the fuel enrichment all other fuel characteristics are the same as in the fuel used in the few most recent cycles. A typical reload cycle after the plant power uprate is examined. Analysis has shown that the current blanket enrichment is close to the optimal. Blanket enrichment reduction results in an approximately 100 000 US$ savings per fuel cycle.(author)

  6. The role of peat in assuring the quality of growing media

    Directory of Open Access Journals (Sweden)

    G. Schmilewski

    2008-02-01

    Full Text Available Producers and users of growing media are exposed to high risk if significant quantities of potentially unsuitable ingredients are included in the product. Combined with economic reasoning, this dictates that the constituents of growing media should possess as many suitable characteristics as possible. Sphagnum peat has been the most important growing medium constituent for many decades because its properties are the best available. The use of other organic and mineral-organic materials is being forced ahead by research and development against a background of public favour for peat replacement, recycling and re-use of biodegradable waste. Considerably more resources have been invested in the testing of peat alternatives than in peat itself during recent years, and the utility of a large number of alternatives has been assessed. Most candidate materials are only slightly or not at all suitable for use in growing media. The exceptions are composts, wood fibre products, bark and composted bark, and coir. These have become established, to a greater or lesser degree, as reliable substrate constituents. Their manufacture, characteristics, advantages and disadvantages are reviewed. A continuing need for peat as a constituent of growing media, at least for dilution purposes, is foreseen. Thus, increased imports of peat and growing media to countries with intensive or expanding commercial horticulture and inadequate domestic peat reserves are to be expected in the future.

  7. Trade-off study of liquid-metal self-cooled blankets

    International Nuclear Information System (INIS)

    Gohar, Y.

    1986-01-01

    A trade-off study of liquid-metal self-cooled blankets was carried out to define the performance of these blankets with respect to the main functions in a fusion reactor, and to determine the potential to operate at the maximum possible values of the performance parameters. The main purpose is to improve the reactor economics by maximizing the blanket energy multiplication factor, reduce the capital cost of the reactor, and satisfy the design requirements. The main parameters during the course of the study were the tritium breeding ratio (TBR), the blanket energy multiplication factor, the energy fraction lost to the shield, the 6 Li enrichment in the breeder material, the total blanket thickness, the reflector material selection, and the compositions of the different blanket zones. Also, the impact of different reactor design choices on the performance parameters was analyzed. The effect of the impurity control system (limiter or divertor), the material choice for the limiter, the elimination of tritium breeding from the inboard section of tokamak reactors, the coolant choice for the nonbreeding inboard blanket, and the neutron source distribution were part of the trade-off study. In addition, tritium breeding benchmark calculations were performed to study the impact of the use of different transport codes and nuclear data libraries. The importance and the negative effect of high TBR on the energy multiplication motivated the benchmark calculations

  8. Design and analysis of ITER shield blanket

    Energy Technology Data Exchange (ETDEWEB)

    Ohmori, Junji; Hatano, Toshihisa; Ezato, Kouichiro [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

    1998-12-01

    This report includes electromagnetic analyses for ITER shielding blanket modules, fabrication methods for the blanket modules and the back plate, the design and the fabrication methods for port limiter have been investigated. Studies on the runaway electron impact for Be armor have been also performed. (J.P.N.)

  9. Processing and waste disposal needs for fusion breeder blankets system

    International Nuclear Information System (INIS)

    Finn, P.A.; Vogler, S.

    1988-01-01

    We evaluated the waste disposal and recycling requirements for two types of fusion breeder blanket (solid and liquid). The goal was to determine if breeder blanket waste can be disposed of in shallow land burial, the least restrictive method under U.S. Nuclear Regulatory Commission regulations. Described in this paper are the radionuclides expected in fusion blanket materials, plans for reprocessing and disposal of blanket components, and estimates for the operating costs involved in waste disposal. (orig.)

  10. Markers of Soil Organic Matter Transformation in Permafrost Peat Mounds of Northeastern Europe

    Science.gov (United States)

    Pastukhov, A. V.; Knoblauch, C.; Yakovleva, E. V.; Kaverin, D. A.

    2018-01-01

    For the paleoreconstruction of permafrost peat mounds and the identification of plant communities participating in the formation of peat, the contents of n-alkanes (C20-C33) have been determined, and relative changes in the stable isotope compositions of carbon and nitrogen and the C/N ratio have been analysed. Several indices ( CPI alkanes, P aq, P wax) have been calculated to assess the degree of decomposition of the peats studied and the contributions of different plant species to their formation. It has been found that shortand long-chain n-alkanes are concentrated in high-moor peat, while medium-chain alkanes are typical for transitional peat. Integrated analysis of the studied markers has shown that the botanical and material composition of peat, anaerobic conditions of bog formation, and permafrost play an important role in the preservation of organic carbon in permafrost peat mounds. Alternation of plant associations is the main reason for changes in n-alkane concentrations, C/N ratios, and δ13C values.

  11. Epoxy blanket protects milled part during explosive forming

    Science.gov (United States)

    1966-01-01

    Epoxy blanket protects chemically milled or machined sections of large, complex structural parts during explosive forming. The blanket uniformly covers all exposed surfaces and fills any voids to support and protect the entire part.

  12. A Study on Factors Affecting Strength of Solidified Peat through XRD and FESEM Analysis

    Science.gov (United States)

    Rahman, J. A.; Napia, A. M. A.; Nazri, M. A. A.; Mohamed, R. M. S. R.; Al-Geethi, A. S.

    2018-04-01

    Peat is soft soil that often causes multiple problems to construction. Peat has low shear strength and high deformation characteristics. Thus, peat soil needs to be stabilized or treated. Study on peat stabilization has been conducted for decades with various admixtures and mixing formulations. This project intends to provide an overview of the solidification of peat soil and the factors that affecting the strength of solidified peat soil. Three types of peats which are fabric, hemic and sapric were used in this study to understand the differences on the effect. The understanding of the factors affecting strength of solidified peat in this study is limited to XRD and FESEM analysis only. Peat samples were collected at Pontian, Johor and Parit Raja, Johor. Peat soil was solidified using fly ash, bottom ash and Portland cement with two mixing formulation following literature review. The solidified peat were cured for 7 days, 14 days, 28 days and 56 days. All samples were tested using Unconfined Compressive Strength Test (UCS), X-ray diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM). The compressive strength test of solidified peat had shown consistently increase of sheer strength, qu for Mixing 1 while decrease of its compressive strength value for Mixing 2. All samples were tested and compared for each curing days. Through XRD, it is found that all solidified peat are dominated with pargasite and richterite. The highest qu is Fabric Mixing 1(FM1) with the value of 105.94 kPa. This sample were proven contain pargasite. Samples with high qu were observed to be having fly ash and bottom ash bound together with the help of pargasite. Sample with decreasing strength showed less amount of pargasite in it. In can be concluded that XRD and FESEM findings are in line with UCS values.

  13. 18 CFR 284.303 - OCS blanket certificates.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false OCS blanket certificates. 284.303 Section 284.303 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Pipelines on Behalf of Others § 284.303 OCS blanket certificates. Every OCS pipeline [as that term is...

  14. Mineral capacity of peat soils organic matter and entry of Cs137 into perennial grasses

    International Nuclear Information System (INIS)

    Tsybulko, N.N.; Shapsheeva, T.P.; Arastovich, T.V.; Zajtsev, A.A.

    2010-01-01

    The results of the study of peat soils organic substance structure with various peat ash content are given. Contents of active organic substance and carbon of microbial biomass in peat and boggy soil with 20% peat ash content is 3.0-3.5 and 1.6-1.8 times higher correspondingly, than thus in peaty-gley soil with 70% peat ash content. At peat and boggy soil with low peat ash content Cs137 transition into hay is minimal. 14 times higher than at peaty-gley soil with 70% peat ash content. Application of fertilizers at peat and boggy soil reduces Cs137 transition factor 4.7-6.4 times if compared to peaty-gley soil (2.1-4.7 times). Close positive interconnection between Cs137 transition factors from soil into the plants and organic carbon soil contents, absolute contents of potentially mineralized carbon and mineralization degree

  15. Volatile and semivolatile organic compounds in laboratory peat fire emissions

    Data.gov (United States)

    U.S. Environmental Protection Agency — Supporting information Tables S3 and S4 list emission factors in g/kg of speciated volatile and particulate organic compounds emitted from peat burning. Peat samples...

  16. Score Mining Rents in Terms of Investment Attractiveness of Peat Mining

    Science.gov (United States)

    Alexandrov, Gennady; Yablonev, Alexander

    2017-11-01

    In this article, as determinants in the system factors underlying the investment attractiveness of the peat industry is considered a rental factor, which predetermines the significant differences and peculiarities of the investment climate in the mining business and, in particular, in the sphere of peat mining. In contrast to modern studies treated the essence and role of rents in the economic mechanism, is proposed for a new approach to solving the problems of its formation. Our approach differs in that it, firstly, adequate rental relations, objectively in extractive industries, secondly, provides consensus in the interests of the owner of peat deposits and entrepreneurs, businesses in these deposits and, thus, thirdly, contributes to the creation of a favourable investment climate in the peat extraction industry. In practical terms, in accordance with the proposed approach, we have proposed specific allocation algorithm of mining rents from the profits of peat extraction enterprises.

  17. Microbial Activity in Peat Soil Treated With Ordinary Portland Cement (OPC) and Coal Ashes

    Science.gov (United States)

    Rahman, J. A.; Mohamed, R. M. S. R.; Al-Gheethi, A. A.

    2018-04-01

    Peat soil is a cumulative of decayed plant fragment which developed as a result of microbial activity. The microbes degrade the organic matter in the peat soils by the production of hydrolysis enzyme. The least decomposed peat, known as fibric peat has big particles and retain lots of water. This made peat having high moisture content, up to 1500 %. The most decomposed peat known as sapric peat having fines particles and less void ratio. The present study aimed to understand the effects of solidification process on the bacterial growth and cellulase (CMCase) enzyme activity. Two types of mixing were designed for fibric, hemic and sapric peats; (i) Ordinary Portland cement (OPC) at an equal amount of dry peat, with 25 % of fly ash (FA) and total of coarse particle, a combination of bottom ash and fibre of 22 – 34 %, (ii) fibric peat was using water-to-binder ratio (w/b) = 1, 50% OPC, 25 % bottom ash (BA) and 25 % FA. For hemic and sapric peat, w/b=3 with 50 % OPC and 50 % BA were used. All samples were prepared triplicates, and were cured for 7, 14, 28 and 56 days in a closed container at room temperature. The results revealed that the first mix design giving a continuous strength development. However, the second mix design shows a decreased in strength pattern after day 28. The influence of the environment factors such as alkaline pH, reduction of the water content and peat temperature has no significant on the reduction amount of native microbes in the peat. The microbes survived in the solidified peat but the amount of microbes were found reduced for all types of mixing Fibric Mixed 1 (FM1), Hemic Mixed 1(HM1) and Sapric Mixed 1 (SM1) were having good strength increment for about 330 – 1427 % with enzymatic activity recorded even after D56. Nevertheless, with increase in the strength development through curing days, the enzymatic activities were reduced. For the time being, it can be concluded that the microbes have the ability to adapt with new environment

  18. Low-rank coal study: national needs for resource development. Volume 6. Peat

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    The requirements and potential for development of US peat resources for energy use are reviewed. Factors analyzed include the occurrence and properties of major peat deposits; technologies for extraction, dewatering, preparation, combustion, and conversion of peat to solid, liquid, or gaseous fuels; environmental, regulatory, and market constraints; and research, development, and demonstration (RD and D) needs. Based on a review of existing research efforts, recommendations are made for a comprehensive national RD and D program to enhance the use of peat as an energy source.

  19. Impact on the greenhouse effect of peat mining and combustion

    International Nuclear Information System (INIS)

    Rodhe, H.; Svensson, Bo

    1995-01-01

    Combustion of peat leads to emission of carbon dioxide (CO 2 ) in the atmosphere. In addition, mining of the peat alters the environment such that the natural fluxes of CO 2 and other greenhouse gases are modified. Of particular interest is a reduction in the emission of methane (CH 4 ) in the drained parts of the mires. We estimate the total impact on the greenhouse effect of these processes. The results indicate that the decreased emission of methane from the drained mires compensates for about 15% of the CO 2 emission during the combustion of the peat. It follows that, in a time perspective of less than several hundred years, peat is comparable to a fossil fuel, as far as the contribution to the greenhouse effect is concerned. 39 refs, 1 fig, 4 tabs

  20. Gasification of peat and biomass in suspension. Turpeen ja biomassan suspensiokaasutus

    Energy Technology Data Exchange (ETDEWEB)

    Haukka, P.; Raiko, R.

    1993-01-01

    Gasification of peat and biomass in dilute particle-gas suspension has not been studied significantly in Finland, even though these fuels require drying, which often produces dry pulverized fuel. This report has concentrated on studying suitability of so-called two-stage entrained-bed gasification for peat and biomass. The gasification system consists of a pyrolysis reactor (entrained flow) and an adiabatic char combustor. Dry or almost dry fuel is fed into the hot flue gas stream coming from the char combustor. Gasification is based on flash pyrolysis in the dilute suspension flow. Residual char is separated from pyrolyzer gases in a gas cleaning device and fed back to the adiabatic combustor. In the combustor char is burned at high temperature to supply the heat required to support endothermic reactions occurring in the pyrolyzer. To study entrained-bed gasification two types of computer models were developed: steady state simulation model and kinetic pyrolyzer model. With the help of these computer models mass and energy balances of the gasifier can be solved and the main dimensions of the gasifier can be determined. Lack of proper kinetic parameters for fast pyrolysis of peat and biomass makes it more difficult to apply the kinetic model in practice. Quantitative data concerning fast pyrolysis in dilute gas-particle suspension are needed to be able to evaluate the performance of the suspension gasifier in more detail. Gasifier operation has been studied using three different levels for amounts of pyrolysis pro- ducts, nine pressure levels between 15-23 bars and five temperature levels between 800-1200 deg C. Furthermore, normal pressure performance was simulated. In addition to simulation studies product gas heating value was optimized

  1. Japanese contributions to the Japan-US workshop on blanket design/technology

    International Nuclear Information System (INIS)

    Tone, Tatsuzo; Seki, Yasushi; Minato, Akio; Kobayashi, Takeshi; Mori, Seiji; Kawasaki, Hiromitsu; Sumita, Kenji.

    1983-02-01

    This report describes Japanese papers presented at the Japan-US Workshop on Blanket Design/Technology which was held at Argonne National Laboratory, November 10 - 11, 1982. Overview of Fusion Experimental Reactor (FER), JAERI's activities related to first wall/blanket/shield, summary of FER blanket and its technology development issues and summary of activities at universities on fusion reactor blanket engineering are covered. (author)

  2. Cassette blanket and vacuum building: key elements in fusion reactor maintenance

    International Nuclear Information System (INIS)

    Werner, R.W.

    1977-01-01

    The integration of two concepts important to fusion power reactors is discussed. The first concept is the vacuum building which improves upon the current fusion reactor designs. The second concept, the use of the cassette blanket within the vacuum building environment, introduces four major improvements in blanket design: cassette blanket module, zoning concept, rectangular blanket concept, and internal tritium recovery

  3. Remediation of diesel-oil-contaminated soil using peat

    International Nuclear Information System (INIS)

    Ghaly, R.A.; Pyke, J.B.; Ghaly, A.E.; Ugursal, V.I.

    1999-01-01

    We investigated a remediation process for diesel-contaminated soil, in which water was used to remove the diesel from the soil and peat was used to absorb the diesel layer formed on the surface of the water. The percolation of water through the soil was uniform. The time required for water to percolate the soil and for the layers (soil, water, and diesel) to separate depended on the soil depth. Both the depth of soil and mixing affected the thickness of the diesel layer and thus diesel recovery from the contaminated soil. Higher diesel recovery was achieved with smaller soil depth and mixing. The initial moisture content and the lower heating value of the peat were 7.1% and 17.65 MJ/kg, respectively. The final moisture content and lower heating value of the diesel-contaminated peat obtained from the experiment with mixing were 8.65 - 10.80% and 32.57 - 35.81 MJ/kg, respectively. The energy content of the diesel-contaminated peat is much higher than that of coal, and the moisture content is within the range recommended for biomass gasification. (author)

  4. Application of peat filters for treating milkhouse wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Fahie, C.R.; Gagnon, G.A. [Dalhousie Univ., Dept. of Civil Engineering, Halifax, Nova Scotia (Canada); Gordon, R.J. [Nova Scotia Agricultural College, Dept. of Engineering, Bible Hill, Nova Scotia (Canada)

    2002-06-15

    This study investigates the suitability of using peat as a filtering media for the treatment of agricultural wastewater. A full-scale experimental filter system was used to evaluate the ability of the filter system to treat milkhouse wastewater. The full-size modular peat filtration system was installed and monitored on a dairy farm located in Hilden, NS. The peat filter models used in the study were constructed from pre-cast concrete, which are approximately 3.2 m long by 1.8 m wide and 1.0 m high and filled are packed with sphagnum peat moss compacted to a density of 0.15 g cm{sup -3} . Parameters that were monitored include BOD, pH, NO{sub 3}-N, SO{sub 4}, TSS, SRP, and TP. The milkhouse wastewater was characterized by having a BOD{sub 5} of approximately 1500 mg L{sup -1} , an average TSS concentration of 510 mg L{sup -1} and an average SRP concentration of 100 mg L{sup -1} . Removal efficiencies of BOD{sub 5} and TSS were observed to be 59% and 82% respectively. In general, phosphorus removal was poor and subsequent research will examine mechanisms of improving phosphorus removal. (author)

  5. Application of peat filters for treating milkhouse wastewater

    International Nuclear Information System (INIS)

    Fahie, C.R.; Gagnon, G.A.; Gordon, R.J.

    2002-01-01

    This study investigates the suitability of using peat as a filtering media for the treatment of agricultural wastewater. A full-scale experimental filter system was used to evaluate the ability of the filter system to treat milkhouse wastewater. The full-size modular peat filtration system was installed and monitored on a dairy farm located in Hilden, NS. The peat filter models used in the study were constructed from pre-cast concrete, which are approximately 3.2 m long by 1.8 m wide and 1.0 m high and filled are packed with sphagnum peat moss compacted to a density of 0.15 g cm -3 . Parameters that were monitored include BOD, pH, NO 3 -N, SO 4 , TSS, SRP, and TP. The milkhouse wastewater was characterized by having a BOD 5 of approximately 1500 mg L -1 , an average TSS concentration of 510 mg L -1 and an average SRP concentration of 100 mg L -1 . Removal efficiencies of BOD 5 and TSS were observed to be 59% and 82% respectively. In general, phosphorus removal was poor and subsequent research will examine mechanisms of improving phosphorus removal. (author)

  6. Peat decomposition records in three pristine ombrotrophic bogs in southern Patagonia

    Directory of Open Access Journals (Sweden)

    T. Broder

    2012-04-01

    Full Text Available Ombrotrophic bogs in southern Patagonia have been examined with regard to paleoclimatic and geochemical research questions but knowledge about organic matter decomposition in these bogs is limited. Therefore, we examined peat humification with depth by Fourier Transformed Infrared (FTIR measurements of solid peat, C/N ratio, and δ13C and δ15N isotope measurements in three bog sites. Peat decomposition generally increased with depth but distinct small scale variation occurred, reflecting fluctuations in factors controlling decomposition. C/N ratios varied mostly between 40 and 120 and were significantly correlated (R2 > 0.55, p < 0.01 with FTIR-derived humification indices. The degree of decomposition was lowest at a site presently dominated by Sphagnum mosses. The peat was most strongly decomposed at the driest site, where currently peat-forming vegetation produced less refractory organic material, possibly due to fertilizing effects of high sea spray deposition. Decomposition of peat was also advanced near ash layers, suggesting a stimulation of decomposition by ash deposition. Values of δ13C were 26.5 ± 2‰ in the peat and partly related to decomposition indices, while δ15N in the peat varied around zero and did not consistently relate to any decomposition index. Concentrations of DOM partly related to C/N ratios, partly to FTIR derived indices. They were not conclusively linked to the decomposition degree of the peat. DOM was enriched in 13C and in 15N relative to the solid phase probably due to multiple microbial modifications and recycling of N in these N-poor environments. In summary, the depth profiles of C/N ratios, δ13C values, and FTIR spectra seemed to reflect changes in environmental conditions affecting decomposition, such as bog wetness, but were dominated by site specific factors, and are further influenced by ash

  7. Studies on liquefaction and pyrolysis of peat and biomass at KTH

    International Nuclear Information System (INIS)

    Bjoernbom, E.; Sjoestrom, K.; Hoernel, C.; Zanzi, R.; Bjoernbom, P.

    1996-01-01

    A brief review of the study on thermochemical conversion of solid fuels is done. The study have been performed in the Royal Institute of Technology, Stockholm, since the outbreak of energy crisis in the seventies. The main problems connected with utilisation of peat for energy are: 90% moisture content in the deposits and 35-40% oxygen content in the dry substance. Simultaneous dewatering and liquefaction of peat have been achieved by the Bjoerbom method. The wet peat has been treated with CO and H 2 O without preliminary drying, using water as a medium agent. After treatment water has been phase-separated from the heavy oil product. Another approach is de-oxygenation of peat prior to liquefaction. A significant part of oxygen in peat and biomass can be removed by thermal decomposition of the fuels prior to liquefaction and removal of carbon dioxide and water from the organic matter in them. The products obtained after de-oxygenation demand low consumption of external hydrogenation agent because they are rich in hydrogen. Some criteria for selection of peat as a raw material for liquefaction are given. The equipment and experimental procedure for pyrolysis of peat and biomass are described. A free fall tubular reactor with max operating pressure of 5 MPa and temperature of 1100 o C has been used. The effect of treatment conditions under the rapid pyrolysis in the free fall reactor on the yield and the reactivity of char obtained after the final pyrolysis is shown. Peat and wood are transformed into pyrolysis products for less than 1 second; 35-50% of the moisture- and ash-free peat and 70% of the wood have been converted into gaseous products.The char obtained in the rapid pyrolysis contains a fraction which can be further de-volatilized by slow pyrolysis for a few minutes - time much longer than the time for formation of primary products. High reactivity of char is favoured by lower pyrolysis temperature, shorter residence time and larger particle size of the fuel

  8. Peat in horticulture and conservation: the UK response to a changing world

    Directory of Open Access Journals (Sweden)

    P.D. Alexander

    2008-11-01

    Full Text Available Peat bogs are increasingly recognised as valuable habitats for wildlife and important stores of carbon. Yet the UK horticultural industry relies heavily on peat sourced from bogs in the UK and Republic of Ireland. Environmentalists, government and horticultural businesses in the UK now recognise the environmental consequences of using peat in horticulture, and the industry is turning increasingly to sustainable raw materials. In this paper, the strengths and weaknesses of campaigning since 1990 to implement this change are analysed, with the intention of providing useful information for other countries facing similar challenges. The campaign encountered deeply-ingrained practices so that the shift in behaviour has been slow and, although now widespread, still meets resistance in some quarters. The UK Government introduced targets for peat replacement which have helped stimulate the industry to develop suitable alternatives. The major gardening retailers have included peat replacement targets in their environmental codes of practice, and these are being met through incremental peat dilution with alternative materials such as green compost and processed timber by-products. Legislative requirements for European biodiversity conservation have led the UK government to terminate peat extraction on significant areas of former commercial extraction. The importance of peatlands for carbon sequestration and the major issue of climate change are increasingly focusing attention on peatland conservation, pointing towards the need for a more consistent approach to the use of peat across the European Community.

  9. GIS-based examination of peats and soils in Surfers Paradise, Australia

    Directory of Open Access Journals (Sweden)

    Al-Ani Haider

    2014-03-01

    Full Text Available The subsoil conditions of Surfers Paradise in Southeast Queensland of Australia have been examined in terms of soil stiffness by using geographic information system (GIS. Peat is a highly organic and compressible material. Surfers Paradise (as a study area has problematic peat layer due to its high water content, high compressibility, and low shear strength. This layer has various thicknesses at different locations ranging between R.L. . 10 to R.L. -19.6 m. Buildings in Surfers Paradise are using piled foundations to avoid the high compressibility and low shear strength peat layer. Spatial Analyst extension in the GIS ArcMap10 has been utilised to develop zonation maps for different depths in the study area. Each depth has been interpolated as a surface to create Standard Penetration Test SPT-N value GIS-based zonation maps for each depth. In addition, 8 interpolation techniques have been examined to evaluate which technique gives better representation for the Standard Penetration Test (SPT data. Inverse Distance weighing (IDW method in Spatial Analyst extension gives better representation for the utilised data with certain parameters. Two different cross sections have been performed in the core of the study area to determine the extent and the depth of the peat layer underneath already erected buildings. Physical and engineering properties of the Surfers Paradise peat have been obtained and showed that this peat falls within the category of tropical peat.

  10. Neutronics analysis for aqueous self-cooled fusion reactor blankets

    International Nuclear Information System (INIS)

    Varsamis, G.; Embrechts, M.J.; Jaffa, R.; Steiner, D.; Deutsch, L.; Gierszewski, P.

    1986-06-01

    The tritium breeding performance of several Aqueous Self-Cooled Blanket (ASCB) configurations for fusion reactors has been evaluated. The ASCB concept employs small amounts of lithium compound dissolved in light or heavy water to serve as both coolant and breeding medium. The inherent simplicity of this concept allows the development of blankets with minimal technological risk. The tritium breeding performance of the ASCB concept is a critical issue for this family of blankets. Contrary to conventional blanket designs there will be a significant contribution to the tritium breeding ratio (TBR) in the water coolant/breeder of duct shields, and the 3-D TBR will therefore be similar to the 1-D TBR. The tritium breeding performance of an ASCB for a MARS-like-tandem reactor and an ASCB based breeding-shield for the Next European Torus (NET) are assessed. Two design options for the MARS-like blanket are discussed. One design employs a vanadium first wall, and zircaloy for the structural material. The trade-offs between light water and heavy water cooling options for this zircaloy blanket are discussed. The second design option for MARS relies on the use of a vanadium alloy as the stuctural material, and heavy water as the coolant. It is demonstrated that both design options lead to low-activation blankets that allow class C burial. The breeder-shield for NET consists of a water-cooled stainless steel shield

  11. EU DEMO blanket concepts safety assessment. Final report of Working Group 6a of the Blanket Concept Selection Exercise

    International Nuclear Information System (INIS)

    Kleefeldt, K.; Porfiri, T.

    1996-06-01

    The European Union has been engaged since 1989 in a programme to develop tritium breeding blankets for application in a fusion power reactor. There are four blanket concepts under development. Two of them use lithium ceramics, the other two concepts employ an eutectic lead-lithium alloy (Pb-17Li) as breeder material. The two most promising concepts were to select in 1995 for further development. In order to prepare the selection, a Blanket Concept Selection Exercise (BCSE) has been inititated by the participating associations under the auspices of the European Commission. This BCSE has been performed in 14 working groups which, in a comparative evaluation of the four blanket concepts, addressed specific fields. The working group safety addressed the safety implications. This report describes the methodology adopted, the safety issues identified, their comparative evaluation for the four concepts, and the results and conclusions of the working group to be entered into the overall evaluation. There, the results from all 14 working groups have been combined to yield a final ranking as a basis for the selection. In summary, the safety assessment showed that the four European blanket concepts can be considered as equivalent in terms of the safety rating adopted, each concept, however, rendering safety concerns of different quality in different areas which are substantiated in this report. (orig.) [de

  12. Tritium transport in the water cooled Pb-17Li blanket concept of DEMO

    International Nuclear Information System (INIS)

    Reiter, F.; Tominetti, S.; Perujo, A.

    1992-01-01

    The code TIRP has been used to calculate the time dependence of tritium inventory and tritium permeation into the coolant and into the first wall boxes in the water cooled Pb-17Li blanket concept of DEMO. The calculations have been performed for the martensitic steel MANET and the austenitic steel AISI 316L as blanket structure materials, for water or helium cooling and for convective or no motion of the liquid breeder in the blanket. Tritium inventories are rather low in blankets with MANET structure and higher in those with AISI 316L structure. Tritium permeation rates are too high in both blankets. Further calculations on tritium inventory and permeation are therefore presented for blankets with TiC permeation barriers of 1 μm thickness on various surfaces of the blanket structure and for blankets with any permeation barriers in function of their thickness, tritium diffusivities, tritium surface recombination rates and atomic densities. These last calculations have been performed for a blanket with coatings on the outer surfaces of the blanket and with a tritium residence time of 10 4 s and for a blanket with coatings on both sides of the cooling tubes and stagnant Pb-17Li in the blanket. The second case for a blanket with MANET structure presents a very interesting solution for tritium recovery by permeation into and pumping from the first wall boxes. (orig.)

  13. Fusion breeder sphere - PAC blanket design

    International Nuclear Information System (INIS)

    Sullivan, J.D.; Palmer, B.J.F.

    1987-11-01

    There is a considerable world-wide effort directed toward the production of materials for fusion reactors. Many ceramic fabrication groups are working on making lithium ceramics in a variety of forms, to be incorporated into the tritium breeding blanket which will surround the fusion reactor. Current blanket designs include ceramic in either monolithic or packed sphere bed (sphere-pac) forms. The major thrust at AECL is the production of lithium aluminate spheres to be incorporated in a sphere-pac bed. Contemporary studies on breeder blanket design offer little insight into the requirements on the sizes of the spheres. This study examined the parameters which determine the properties of pressure drop and coolant requirements. It was determined that an optimised sphere-pac bed would be composed of two diameters of spheres: 75 weight % at 3 mm and 25 weight % at 0.3 mm

  14. Influences of deforestation on radiation and heat balances in tropical peat swamp forest in Thailand

    International Nuclear Information System (INIS)

    Suzuki, S.; Ishida, T.; Nagano, T.; Matsukawa, S.

    1997-01-01

    The difference of radiation and heat balances between a natural peat swamp forest and a deforested secondary forest has been investigated in Narathiwat Province, Thailand. Micrometeorological measurements were conducted continuously on observation towers 38 m and 4 m in heights in the primary forest and the secondary forest respectively. Results show that the deforestation of peat swamp forest leads to an increase in the sensible heat flux in the secondary forest. The yearly average ratio of the sensible heat flux to the net radiation was 20.9% in the peat swamp forest, and 33.2% in the secondary forest from Aug. 1995 to Jul. 1996. A ratio more than 40% was observed only in the dry season in the secondary forest. The change in sensible heat flux seemed to be influenced by the change in ground water levels. (author)

  15. Effect of reactor size on the breeding economics of LMFBR blankets

    International Nuclear Information System (INIS)

    Tagishi, A.; Driscoll, M.J.

    1975-02-01

    The effect of reactor size on the neutronic and economic performance of LMFBR blankets driven by radially-power-flattened cores has been investigated using both simple models and state-of-the-art computer methods. Reactor power ratings in the range 250 to 3000 MW(e) were considered. Correlations for economic breakeven and optimum irradiation times and blanket thicknesses have been developed for batch-irradiated blankets. It is shown that a given distance from the core-blanket interface the fissile buildup rate per unit volume remains very nearly constant in the radial blanket as (radially-power-flattened, constant-height) core size increases. As a consequence, annual revenue per blanket assembly, and breakeven and optimum irradiation times and optimum blanket dimensions, are the same for all reactor sizes. It is also shown that the peripheral core fissile enrichment, hence neutron leakage spectra, of the (radially-power-flattened, constant-height) cores remains essentially constant as core size increases. Coupled with the preceding observations, this insures that radial blanket breeding performance in demonstration-size LMFBR units will be a good measure of that in much larger commercial LMFBR's

  16. Benchmarking Environmental Impacts of Peat Use for Electricity Generation in Ireland—A Life Cycle Assessment

    Directory of Open Access Journals (Sweden)

    Fionnuala Murphy

    2015-05-01

    Full Text Available The combustion of peat for energy generation accounts for approximately 4.1% of Ireland’s overall greenhouse gas (GHG emissions, with current levels of combustion resulting in the emission of 2.8 Mt of CO2 per annum. The aim of this research is to evaluate the life cycle environmental impacts of peat use for energy generation in Ireland, from peatland drainage and industrial extraction, to transportation, combustion, and subsequent after-use of the cutaway area, utilising Irish-specific emission factors. The environmental impacts considered are global warming potential, acidification potential, and eutrophication potential. In addition, the cumulative energy demand of the system is evaluated. Previous studies on the environmental impact of peat for energy in Ireland relied on default Intergovernmental Panel on Climate Change (IPCC emission factors (EFs. This research utilises Irish-specific EFs and input data to reduce uncertainty associated with the use of default IPCC EFs, and finds that using default IPCC EFs overestimates the global warming potential when compared to Irish-specific EFs by approximately 2%. The greatest contribution to each of the environmental impacts considered arises from emissions generated during peat combustion, which accounts for approximately 95% of each of the environmental impact categories considered. Other stages of the life-cycle, such as impacts emanating from the peat extraction area, fossil fuel usage in harvesting and transportation machinery, and after-use of the cutaway area have much smaller effects on overall results. The transformation of cutaway peatlands to different after-use alternatives has the potential to mitigate some of the effects of peatland degradation and peat combustion.

  17. Assessment of alkali metal coolants for the ITER blanket

    International Nuclear Information System (INIS)

    Natesan, K.; Reed, C.B.; Mattas, R.F.

    1994-01-01

    The blanket system is one of the most important components of a fusion reactor because it has a major impact on both the economics and safety of fusion energy. The primary functions of the blanket in a deuterium/tritium-fueled fusion reactor are to convert the fusion energy into sensible heat and to breed tritium for the fuel cycle. The Blanket Comparison and Selection Study, conducted earlier, described the overall comparative performance of different blanket concepts, including liquid metal, molten salt, water, and helium. This paper will discuss the ITER requirements for a self-cooled blanket concept with liquid lithium and for indirectly cooled concepts that use other alkali metals such as NaK. The paper will address the thermodynamics of interactions between the liquid metals (i.e., lithium and NaK) and structural materials (e.g., V-base alloys), together with associated corrosion/compatibility issues. Available experimental data will be used to assess the long-term performance of the first wall in a liquid metal environment

  18. Analysis of ER string test thermally instrumented interconnect 80-K MLI blanket

    International Nuclear Information System (INIS)

    Daly, E.; Pletzer, R.

    1992-04-01

    An 80-K Multi Layer Insulation (MLI) blanket in the interconnect region between magnets DD0019 and DD0027 in the Fermi National Accelerator Laboratory (FNAL) ER string was instrumented with temperature sensors to obtain the steady-state temperature gradient through the blanket after string cooldown. A thermal model of the 80-K blanket assembly was constructed to analyze the steady-state temperature gradient data. Estimates of the heat flux through the 80-K MLI blanket assembly and predicted temperature gradients were calculated. The thermal behavior of the heavy polyethylene terapthalate (PET) cover layers separating the shield and inner blanket and inner and outer blankets was derived empirically from the data. The results of the analysis predict a heat flux of 0.363--0.453 W/m 2 based on the 11 sets of data. These flux values are 33--46% below the 80-K MLI blanket heat leak budget of 0.676 W/m 2 . The effective thermal resistance of the two heavy PET cover layers between the shield and inner blanket was found to be 2.1 times that of a single PET spacer layer, and the effective resistance of the two heavy PET cover layers between the inner blanket and outer blanket was found to be 7 times that of a single PET spacer layer. Based on these results, the 80-K MLI blanket assembly appears to be performing more than adequately to meet the 80-K static IR heat leak budget. However, these results should not be construed as a verification of the 80-K static IR heat leak, since no actual heat leak was measured. The results have been used to improve the empirically based model data in the 80-K MLI blanket thermal model, which has previously not included the effects of heavy PET cover layers on 80-K MLI blanket thermal performance

  19. A review of fusion breeder blanket technology, part 1

    International Nuclear Information System (INIS)

    Jackson, D.P.; Selander, W.N.; Townes, B.M.

    1985-01-01

    This report presents the results of a study of fusion breeder blanket technology. It reviews the role of the breeder blanket, the current understanding of the scientific and engineering bases of liquid metal and solid breeder blankets and the programs now underway internationally to resolve the uncertainities in current knowledge. In view of existing national expertise and experience, a solid breeder R and D program for Canada is recommended

  20. Economic performance of liquid-metal fast breeder reactor and gas-cooled fast reactor radial blankets

    International Nuclear Information System (INIS)

    Tsoulfanidis, N.; Jankhah, M.H.

    1979-01-01

    The economic performance of the radial blanket of a liquid-metal fast breeder reactor (LMFBR) and a gas-cooled fast reactor (GCFR) has been studied based on the calculation of the net financial gain as well as the value of the levelized fuel cost. The necessary reactor physics calculations have been performed using the code CITATION, and the economic analysis has been carried out with the code ECOBLAN, which has been written for that purpose. The residence time of fuel in the blanket is the main variable of the economic analysis. Other parameters that affect the results and that have been considered are the value of plutonium, the price of heat, the effective cost of money, and the holdup time of the spent fuel before reprocessing. The results show that the radial blanket of both reactors is a producer of net positive income for a broad range of values of the parameters mentioned above. The position of the fuel in the blanket and the fuel management scheme applied affect the monetary gain. There is no significant difference between the economic performance of the blanket of an LMFBR and a GCFR

  1. Investigation of bacterial communities in peat land of the Gahai Lake natural conservation area

    Science.gov (United States)

    Bai, Yani; Wang, Jinchang; Zhan, Zhigao; Guan, Limei; Jin, Liang; Zheng, Guohua

    2017-10-01

    Peat is involved in the global carbon cycle and water conservation; therefore, it is implicated in global environmental change. Microorganisms play an important role in the function of peat. To investigate the bacterial communities in peat of Gahai Lake, different locations and depths were sampled and Illumina Miseq sequencing was used to analyze the microbial community. Chemical properties of peat samples were analyzed by China state standard methods (GB methods). The results showed that bacterial communities were affected by depth, with bacterial diversity and community structure at 90 and 120 cm significantly different from that at 10, 30 and 50 cm depth from the peat surface. Chemical properties of peat land including organic matter, total nitrogen and humus content did not significantly influence bacterial community structure in peat, with only one group from genus Rhizomicrobium that was significantly correlated with total nitrogen. A substantial proportion of the bacterial sequences were unclassified (1.4%), which indicates the great application potential of peat in the Gahai Lake natural conservation area in the future.

  2. Accelerator driven heavy water blanket on circulating fuel

    International Nuclear Information System (INIS)

    Kazaritsky, V.D.; Blagovolin, P.P.; Mladov, V.R.; Okhlopkov, M.L.; Batyaev, V.F.; Stepanov, N.V.; Seliverstov, V.V.

    1997-01-01

    A conceptual design of a heavy water blanket with circulating fuel for an accelerator driven transmutation system is described. The hybrid system consists of a high-current linear accelerator of protons and 4 targets, each placed inside a subcritical blanket

  3. An approach to peat formation period on both coast of Fildes Strait, Antarctica

    International Nuclear Information System (INIS)

    Wenfen, Z.

    1997-01-01

    Because peat consist mainly of organic matter, both credibility and comparability of the peat 14 C age are high. This paper discuss the use of radiocarbon ( 14 C) to study the peat age. The results of a comparative study of ten samples from China Great Wall Station in Antarctica and the nearby area (on both sides of Fildes Strait) are presented, indicating differences of peat formation period between the pole and other areas

  4. FW/Blanket and vacuum vessel for RTO/RC ITER

    International Nuclear Information System (INIS)

    Ioki, K.; Barabash, V.; Cardella, A.; Elio, F.; Iida, H.; Johnson, G.; Kalinin, G.; Miki, N.; Onozuka, M.; Sannazzaro, G.; Utin, Y.; Yamada, M.

    2000-01-01

    The design has progressed on the vacuum vessel and First Wall (FW)/blanket for the Reduced Technical Objective/Reduced Cost (RTO/RC) ITER. The basic functions and structures are the same as for the 1998 ITER design. The design has been improved to achieve, along with the size reduction, ∼50% target reduction of the fabrication cost. The number of blanket modules has been minimized according to smaller dimensions of the machine and a higher payload capacity of the blanket Remote Handling tool. A concept without the back plate has been designed and assessed. The blanket module concept with flat separable FW panels has been developed to reduce the fabrication cost and future radioactive waste

  5. FW/Blanket and vacuum vessel for RTO/RC ITER

    Energy Technology Data Exchange (ETDEWEB)

    Ioki, K. E-mail: iokik@itereu.de; Barabash, V.; Cardella, A.; Elio, F.; Iida, H.; Johnson, G.; Kalinin, G.; Miki, N.; Onozuka, M.; Sannazzaro, G.; Utin, Y.; Yamada, M

    2000-11-01

    The design has progressed on the vacuum vessel and First Wall (FW)/blanket for the Reduced Technical Objective/Reduced Cost (RTO/RC) ITER. The basic functions and structures are the same as for the 1998 ITER design. The design has been improved to achieve, along with the size reduction, {approx}50% target reduction of the fabrication cost. The number of blanket modules has been minimized according to smaller dimensions of the machine and a higher payload capacity of the blanket Remote Handling tool. A concept without the back plate has been designed and assessed. The blanket module concept with flat separable FW panels has been developed to reduce the fabrication cost and future radioactive waste.

  6. Progress in blanket designs using SiCf/SiC composites

    International Nuclear Information System (INIS)

    Giancarli, L.; Golfier, H.; Nishio, S.; Raffray, R.; Wong, C.; Yamada, R.

    2002-01-01

    This paper summarizes the most recent design activities concerning the use of SiC f /SiC composite as structural material for fusion power reactor breeding blanket. Several studies have been performed in the past. The most recent proposals are the TAURO blanket concept in the European Union, the ARIES-AT concept in the US, and DREAM concept in Japan. The first two concepts are self-cooled lithium-lead blankets, while DREAM is an helium-cooled beryllium/ceramic blanket. Both TAURO and ARIES-AT blankets are essentially formed by a SiC f /SiC box acting as a container for the lithium-lead which has the simultaneous functions of coolant, tritium breeder, neutron multiplier and, finally, tritium carrier. The DREAM blanket is characterized by small modules using pebble beds of Be as neutron multiplier material, of Li 2 O (or other lithium ceramics) as breeder material and of SiC as shielding material. The He coolant path includes a flow through the pebble beds and a porous partition wall. For each blanket, this paper describes the main design features and performances, the most recent design improvements, and the proposed manufacturing routes in order to identify specific issues and requirements for the future R and D on SiC f /SiC

  7. Resilient modulus characteristics of soil subgrade with geopolymer additive in peat

    Science.gov (United States)

    Zain, Nasuhi; Hadiwardoyo, Sigit Pranowo; Rahayu, Wiwik

    2017-06-01

    Resilient modulus characteristics of peat soil are generally very low with high potential of deformation and low bearing capacity. The efforts to improve the peat subgrade resilient modulus characteristics is required, one among them is by adding the geopolymer additive. Geopolymer was made as an alternative to replace portland cement binder in the concrete mix in order to promote environmentally friendly, low shrinkage value, low creep value, and fire resistant material. The use of geopolymer to improve the mechanical properties of peat as a road construction subgrade, hence it becomes important to identify the effect of geopolymer addition on the resilient modulus characteristics of peat soil. This study investigated the addition of 0% - 20% geopolymer content on peat soil derived from Ogan Komering Ilir, South Sumatera Province. Resilient modulus measurement was performed by using cyclic triaxial test to determine the resilience modulus model as a function of deviator stresses and radial stresses. The test results showed that an increase in radial stresses did not necessarily lead to an increase in modulus resilient, and on the contrary, an increase in deviator stresses led to a decrease in modulus resilient. The addition of geopolymer in peat soil provided an insignificant effect on the increase of resilient modulus value.

  8. Presence of carotinoids in peat wax

    Energy Technology Data Exchange (ETDEWEB)

    Yurkevich, E.A.; Dolidovich, E.F.; Bel' kevich, P.I.; Sheremet, L.S.; Drozdovskaya, S.V.

    1986-05-01

    Discusses biologically active substances present in peat which have various pharmacological properties. Describes separation of fractions rich in carotinoids from extracts of wax tar obtained by benzine treatment of highly decomposed pine-cotton grass peat. Extraction was carried out using hot ethanol. States that although identification of individual carotinoid in the fractions separated is very difficult due to complicity of composition, the tests carried out made it possible to infer that fractions studied contain not only xanthophylls but also fucoxanthains (formed in small amounts in nature) with fairly stable structure. Ultraviolet and infrared spectra of the carotinoid containing fraction in ethanol extracts are given. 6 refs.

  9. Tritium containment and blanket design challenges for a 1 GWe mirror fusion central power station

    International Nuclear Information System (INIS)

    Galloway, T.R.

    1976-06-01

    Tritium containment and removal problems associated with the blanket and power-systems for a mirror fusion reactor are identified and conceptual process designs are devised to reduce emissions to the environment below 1 Ci/day. The blanket concept development proceeds by starting with this emission goal of 1 Ci/day and working inward to the blanket. At each decision point, worker safety, operational labor costs, and capital cost tradeoffs are contrasted. The conceptual design uses air for the reactor hall with a continuous catalytic oxidizer-molecular sieve adsorber cleanup system to maintain a 40 μCi/m 3 tritium level (5 μCi/m 3 HTO) against 180 Ci/day leakage from reactor components, energy recovery systems, and process piping. This blanket contains submodules with Li 2 Be 2 O 3 --Be for tritium breeding and submodules with Be for mostly energy production. Tritium production in both is handled by separately containing this breeding material and scavenging this container with lithium vapor-doped helium gas stream

  10. Changes of plant cover of the raised peat-bog Baligówka under the influence of human activity

    Directory of Open Access Journals (Sweden)

    Malec Magdalena

    2016-12-01

    Full Text Available The main purpose of the work was to determine the scope and degree of the influence of exploitation on changes of plant cover of the raised peat-bog Baligówka, located in the Orawsko- Nowotarska Valley. The analysis was carried out based on 47 phytosociological surveys using the Braun-Blanquet method. Results of investigations allow to state that excessive drying and fires that took place on the examined object caused wastage of many precious species of plants, especially from the Oxycocco- Sphagnetea class. Their place occupied species belonging to other classes, such as Nardo-Callunetea and Molinio-Arrhenatheretea. The basic cause of drying of the peat-bog and, in consequence, dying of peat formation species is intensified exploitation and connected with this drainage, carried out in the half of the 20th century. Unfortunately, local people up to now illegally have harvested the peat on the investigated object. Decrease in groundwater level leads to accelerated decay of peat, changes in physical and chemical properties of a substratum and, in consequence, changes in trophic values of habitat, what causes great changes in species composition of plant communities.

  11. Radioactivity changes during burning of peat and chip

    International Nuclear Information System (INIS)

    Hedvall, R.; Erlandsson, B.; Mattsson, S.

    1985-01-01

    The increasing use of peat and chip as fuel materials in fossil-fuel power plants has resulted in the need for information about the change in radionuclides concentration in fuel after combustion. The paper describes a study of natural radionuclides from the uranium- and the thorium series and 40 K, as well as fission products from atmospheric nuclear explosions, in ashes from five peat and chip fuelled power plants in Sweden

  12. Overview of the TFTB lithium blanket module program

    International Nuclear Information System (INIS)

    Jassby, D.L.

    1986-01-01

    The Lithium Blanket Module (LBM) is an ∼ 80-cm 3 module, representative of a helium-cooled lithium oxide fusion reactor blanket module. This paper summarizes the design, development, and construction of the LBM, and indicates the present status of the LBM program

  13. Utilization of new materials in peat machines; Uusien materiaalien kaeyttoe turvekoneissa

    Energy Technology Data Exchange (ETDEWEB)

    Kallio, M.; Poeyhoenen, P.

    1996-12-31

    The objective of this three year research (1993-1995) was to study the suitability of new materials for different applications in peat production industry, exploiting the plastic and brush technologies, and surface coatings. The peat production machines will be intensified, lightened, made more firesafe, and ergonomical by using new materials (plastics, composites, metals and surface coatings). The research targets and materials were surveyed, the possibilities to construct an unsparkling miller were investigated, and low-friction materials, on which the peat glides easily, were sought in the beginning of the research. The unsparkling miller was studied and developed further in 1994 using platic plates, the application of brushing technology in sod peat technology, and a ridger, equipped with horizontal brushes, for sod peat were studied, and the possibilities to lighten the construction of the collector-wagon using light materials was investigated. The tasks for 1995 were to study the brushing technology for peat production, the properties of the bristle, and the applications of new materials for milling and sewing of peat using laboratory tests. The brush-ridger tests were made in cooperation with the brush experts of the NIITP. A rotating brush harrower mixed and ruffled the milled layer. The brush-harrower seemed to be more effective than the spoon-harrower with the driving speed higher than 8 km/h. The power consumption of the brush varied in between 1.5 - 4 kW/m, when the rotation speed was 200-300 1/min, the milled layer load 44 mm and the deformation of the bristles 20 mm

  14. Self-shielding characteristics of aqueous self-cooled blankets for next generation fusion devices

    International Nuclear Information System (INIS)

    Pelloni, S.; Cheng, E.T.; Embrechts, M.J.

    1987-11-01

    The present study examines self-shielding characteristics for two aqueous self-cooled tritium producing driver blankets for next generation fusion devices. The aqueous Self-Cooled Blanket concept (ASCB) is a very simple blanket concept that relies on just structural material and coolant. Lithium compounds are dissolved in water to provide for tritium production. An ASCB driver blanket would provide a low technology and low temperature environment for blanket test modules in a next generation fusion reactor. The primary functions of such a blanket would be shielding, energy removal and tritium production. One driver blanket considered in this study concept relates to the one proposed for the Next European Torus (NET), while the second concept is indicative for the inboard shield design for the Engineering Test Reactor proposed by the USA (TIBER II/ETR). The driver blanket for NET is based on stainless steel for the structural material and aqueous solution, while the inboard shielding blanket for TIBER II/ETR is based on a tungsten/aqueous solution combination. The purpose of this study is to investigate self-shielding and heterogeneity effects in aqueous self-cooled blankets. It is found that no significant gains in tritium breeding can be achieved in the stainless steel blanket if spatial and energy self-shielding effects are considered, and the heterogeneity effects are also insignificant. The tungsten blanket shows a 5 percent increase in tritium production in the shielding blanket when energy and spatial self-shielding effects are accounted for. However, the tungsten blanket shows a drastic increase in the tritium breeding ratio due to heterogeneity effects. (author) 17 refs., 9 figs., 9 tabs

  15. Robot vision system R and D for ITER blanket remote-handling system

    International Nuclear Information System (INIS)

    Maruyama, Takahito; Aburadani, Atsushi; Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka; Tesini, Alessandro

    2014-01-01

    For regular maintenance of the International Thermonuclear Experimental Reactor (ITER), a system called the ITER blanket remote-handling system is necessary to remotely handle the blanket modules because of the high levels of gamma radiation. Modules will be handled by robotic power manipulators and they must have a non-contact-sensing system for installing and grasping to avoid contact with other modules. A robot vision system that uses cameras was adopted for this non-contact-sensing system. Experiments for grasping modules were carried out in a dark room to simulate the environment inside the vacuum vessel and the robot vision system's measurement errors were studied. As a result, the accuracy of the manipulator's movements was within 2.01 mm and 0.31°, which satisfies the system requirements. Therefore, it was concluded that this robot vision system is suitable for the non-contact-sensing system of the ITER blanket remote-handling system

  16. Robot vision system R and D for ITER blanket remote-handling system

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Takahito, E-mail: maruyama.takahito@jaea.go.jp [Japan Atomic Energy Agency, Fusion Research and Development Directorate, Naka, Ibaraki-ken 311-0193 (Japan); Aburadani, Atsushi; Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka [Japan Atomic Energy Agency, Fusion Research and Development Directorate, Naka, Ibaraki-ken 311-0193 (Japan); Tesini, Alessandro [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul Lez Durance (France)

    2014-10-15

    For regular maintenance of the International Thermonuclear Experimental Reactor (ITER), a system called the ITER blanket remote-handling system is necessary to remotely handle the blanket modules because of the high levels of gamma radiation. Modules will be handled by robotic power manipulators and they must have a non-contact-sensing system for installing and grasping to avoid contact with other modules. A robot vision system that uses cameras was adopted for this non-contact-sensing system. Experiments for grasping modules were carried out in a dark room to simulate the environment inside the vacuum vessel and the robot vision system's measurement errors were studied. As a result, the accuracy of the manipulator's movements was within 2.01 mm and 0.31°, which satisfies the system requirements. Therefore, it was concluded that this robot vision system is suitable for the non-contact-sensing system of the ITER blanket remote-handling system.

  17. The Characteristics of Peats and Co2 Emission Due to Fire in Industrial Plant Forests

    Science.gov (United States)

    Ratnaningsih, Ambar Tri; Rayahu Prasytaningsih, Sri

    2017-12-01

    Riau Province has a high threat to forest fire in peat soils, especially in industrial forest areas. The impact of fires will produce carbon (CO2) emissions in the atmosphere. The magnitude of carbon losses from the burning of peatlands can be estimated by knowing the characteristics of the fire peat and estimating CO2 emissions produced. The objectives of the study are to find out the characteristics of fire-burning peat, and to estimate carbon storage and CO2 emissions. The location of the research is in the area of industrial forest plantations located in Bengkalis Regency, Riau Province. The method used to measure peat carbon is the method of lost in ignation. The results showed that the research location has a peat depth of 600-800 cm which is considered very deep. The Peat fiber content ranges from 38 to 75, classified as hemic peat. The average bulk density was 0.253 gram cm-3 (0.087-0,896 gram cm-3). The soil ash content is 2.24% and the stored peat carbon stock with 8 meter peat thickness is 10723,69 ton ha-1. Forest fire was predicted to burn peat to a depth of 100 cm and produced CO2 emissions of 6,355,809 tons ha-1.

  18. A method for processing peat or brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Belkevich, P.I.; Lishtvan, I.I.; Prokhorov, G.M.; Tolstikov, G.A.

    1983-01-01

    A method is patented for extraction of peat and brown coal using dimethylformamide or dimethylsulfoxide in order to increase the output of bitumen and to produce dyes and acids from it and to utilize the debituminized fuel. The extraction is conducted at a solvent to raw material ratio of 1 to 5 at a temperature of 95 to 160 degrees for 0.5 to 3 hours. The extract is processed by hydroxides or carbonates of alkaline metals at a ratio of extract to the bitumen of 0.1 to 0.5 at 95 to 160 degrees for 0.5 to 2 hours with isolation of the salts of carbonic acids and recrystallization of them from the hydroxide with the acquisition of the target product of humic acids. The solvent is distilled from the extraction residue and after drying the sediment, a dye D is produced, while the debituminized fuel is processed by hydroxides of alkaline metals in a 0.1 to 1 to 1 ratio at 100 to 150 degrees for 0.5 to 2 hours with the acquisition of thinner for cement solutions. Example. A suspension of 180 grams of peat with a particle size of 0.25 to 10 millimeters with indicators (in percent) of the degree of breakdown of 40, moisture level of 20, ash content of 3.1 and bitumen content of 4.2, is mixed with 810 grams of dimethylformamide (an extraction agent to peat ratio of 4.5) and is heated at 95 degrees for three hours. Eight hundred and seventy grams of the extract (the bitumen output is 33 percent) are acquired, along with 120 grams of debituminized peat. Thirty grams of NaOH (an alkaline to bitumen ratio of 0.5) is gradually added to the bitumen extract at 90 to 100 degrees. The reaction mixture is heated to 160 degrees and is cured at this temperature for 2 hours and subsequently cooled to 20 degrees, filtered off and the salts of the carbonic acids are washed out by a fresh portion of dimethylsulfoxide with the production of 21.3 grams of salts with a melting point of 122 to 175 degrees.

  19. Leaching and retention of nutrients and trace elements in peat nineteen years after wood ash application and afforestation of a terminated peat cutover area; Utlakning och retention av naeringsaemnen och spaaraemnen i torv nitton aar efter vedasktillfoersel och beskogning paa en avslutad torvtaekt

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Torbjoern; Lundin, Lars (Dept. of Forest Soils, Swedish Univ. of Agricultural Sciences, P.O. Box 7001, SE-750 07 Uppsala (Sweden))

    2008-04-15

    Ash application on peatlands for improved biomass production attracts great interest. On drained peatlands in forestry use, application of wood ash would increase the forest production. Before such activities starts on a large-scale, the existing knowledge in this field should be compiled, with the aim to illustrate positive and negative effects of such a measure and to suggest recommendations for wood ash application to drained and afforested peatlands. The aim of this project was to investigate how much of different nutrients and trace elements that was still left in the peat, 19 years after application of 23 tonnes of wood fly ash, 0.6 tonnes of raw phosphate and 0.25 tonnes of superphosphate per hectare to 14 hectares of a terminated peat cutover area. This area was located on a mire, Flakmossen, in west-central Sweden. As it was nearly 40 years since peat harvesting had terminated on this mire, the area was drained before the application of wood ash and phosphorus fertilizer. A tractor-driven cultivator mixed the applied fertilizers with the upper 30-40 cm of the remaining peat and afterwards different tree species were planted in the cultivated peat. Peat sampling, down to 80 cm depth, was carried out before soil treatment, one year after, three years after and 19 years after the soil treatment. Analyses of these peat samples showed that: - After the soil treatments an initial increase of pH in the upper peat layers (0-40 cm depth) was observed, but 19 years after the soil treatments pH had decreased to levels that were lower than before the treatments. This decrease in pH was probably due to an oxidation of sulphur compounds in the peat, which was a result of the drainage. This acidification of the peat could not be buffered by the large dose of applied wood ash. However, it should be observed that the main part of the peat in this field study consists of reed peat, that has a considerable higher sulphur content than other peat types. - Nineteen years after

  20. Blanketing effect of expansion foam on liquefied natural gas (LNG) spillage pool

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bin; Liu, Yi [Mary Kay O’Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A and M University System, College Station, TX 77843-3122 (United States); Olewski, Tomasz; Vechot, Luc [Mary Kay O’Connor Process Safety Center - Qatar, Texas A and M University at Qatar, PO Box 23874, Doha (Qatar); Mannan, M. Sam, E-mail: mannan@tamu.edu [Mary Kay O’Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A and M University System, College Station, TX 77843-3122 (United States)

    2014-09-15

    Highlights: • Reveal the existence of blocking effect of high expansion foam on an LNG pool. • Study the blanketing effect of high expansion foam quantitatively. • Correlate heat flux for vaporization with foam breaking rate. • Propose the physical mechanism of blanketing effect. - Abstract: With increasing consumption of natural gas, the safety of liquefied natural gas (LNG) utilization has become an issue that requires a comprehensive study on the risk of LNG spillage in facilities with mitigation measures. The immediate hazard associated with an LNG spill is the vapor hazard, i.e., a flammable vapor cloud at the ground level, due to rapid vaporization and dense gas behavior. It was believed that high expansion foam mitigated LNG vapor hazard through warming effect (raising vapor buoyancy), but the boil-off effect increased vaporization rate due to the heat from water drainage of foam. This work reveals the existence of blocking effect (blocking convection and radiation to the pool) to reduce vaporization rate. The blanketing effect on source term (vaporization rate) is a combination of boil-off and blocking effect, which was quantitatively studied through seven tests conducted in a wind tunnel with liquid nitrogen. Since the blocking effect reduces more heat to the pool than the boil-off effect adds, the blanketing effect contributes to the net reduction of heat convection and radiation to the pool by 70%. Water drainage rate of high expansion foam is essential to determine the effectiveness of blanketing effect, since water provides the boil-off effect.

  1. Blanketing effect of expansion foam on liquefied natural gas (LNG) spillage pool

    International Nuclear Information System (INIS)

    Zhang, Bin; Liu, Yi; Olewski, Tomasz; Vechot, Luc; Mannan, M. Sam

    2014-01-01

    Highlights: • Reveal the existence of blocking effect of high expansion foam on an LNG pool. • Study the blanketing effect of high expansion foam quantitatively. • Correlate heat flux for vaporization with foam breaking rate. • Propose the physical mechanism of blanketing effect. - Abstract: With increasing consumption of natural gas, the safety of liquefied natural gas (LNG) utilization has become an issue that requires a comprehensive study on the risk of LNG spillage in facilities with mitigation measures. The immediate hazard associated with an LNG spill is the vapor hazard, i.e., a flammable vapor cloud at the ground level, due to rapid vaporization and dense gas behavior. It was believed that high expansion foam mitigated LNG vapor hazard through warming effect (raising vapor buoyancy), but the boil-off effect increased vaporization rate due to the heat from water drainage of foam. This work reveals the existence of blocking effect (blocking convection and radiation to the pool) to reduce vaporization rate. The blanketing effect on source term (vaporization rate) is a combination of boil-off and blocking effect, which was quantitatively studied through seven tests conducted in a wind tunnel with liquid nitrogen. Since the blocking effect reduces more heat to the pool than the boil-off effect adds, the blanketing effect contributes to the net reduction of heat convection and radiation to the pool by 70%. Water drainage rate of high expansion foam is essential to determine the effectiveness of blanketing effect, since water provides the boil-off effect

  2. Soil ecology and ecosystem services of dairy and semi-natural grasslands on peat

    NARCIS (Netherlands)

    Deru, Joachim G.C.; Bloem, Jaap; Goede, de Ron; Keidel, Harm; Kloen, Henk; Rutgers, Michiel; Akker, van den Jan; Brussaard, Lijbert; Eekeren, van Nick

    2018-01-01

    Peat wetlands are of major importance for ecosystem services such as carbon storage, water regulation and maintenance of biodiversity. However, peat drainage for farming leads to CO2 emission, soil subsidence and biodiversity losses. In the peat areas in the Netherlands, solutions are sought in

  3. The fusion blanket program at Chalk River

    International Nuclear Information System (INIS)

    Hastings, I.J.

    1986-03-01

    Work on the Fusion Blanket Program commenced at Chalk River in 1984 June. Co-funded by Canadian Fusion Fuels Technology Project and Atomic Energy of Canada Limited, the Program utilizes Chalk River expertise in instrumented irradiation testing, ceramics, tritium technology, materials testing and compound chemistry. This paper gives highlights of studies to date on lithium-based ceramics, leading contenders for the fusion blanket

  4. An analytical protocol for the determination of total mercury concentrations in solid peat samples

    DEFF Research Database (Denmark)

    Roos-Barraclough, F; Givelet, N; Martinez-Cortizas, A

    2002-01-01

    Traditional peat sample preparation methods such as drying at high temperatures and milling may be unsuitable for Hg concentration determination in peats due to the possible presence of volatile Hg species, which could be lost during drying. Here, the effects of sample preparation and natural.......12 and 8.52 ng kg(-1) h(-1), respectively). Fertilising the peat slightly increased Hg loss (3.08 ng kg(-1) h(-1) in NPK-fertilised peat compared to 0.28 ng kg(-1) h(-1) in unfertilised peat, when averaged over all temperatures used). Homogenising samples by grinding in a machine also caused a loss of Hg....... A comparison of two Hg profiles from an Arctic peat core, measured in frozen samples and in air-dried samples, revealed that no Hg losses occurred upon air-drying. A comparison of Hg concentrations in several plant species that make up peat, showed that some species (Pinus mugo, Sphagnum recurvum...

  5. Distribution, classification, petrological and related gochemical (SRA) characteristics of a tropical lowland peat dome in the Kota Samarahan-Asajaya area, West Sarawak, Malaysia

    Science.gov (United States)

    Zulkifley, Mohamad Tarmizi Mohamad; Fatt, Ng Tham; Abdullah, Wan Hasiah; Raj, John Kuna; Paramanathan Param, S.; Hashim, Roslan; Ashraf, Muhammad Aqeel

    2013-06-01

    Petrographic studies indicate that lateral variations in the decomposition levels of peat are associated with the predominantly occurring peat macerals. Source Rock Analyzer (SRA) results indicate lateral variation in peat organic matter types from type II to III and back again to type II, occurring laterally within the top 0-m to 0.5-m layer at the basin margin to the midsection and further towards the near-center areas of the peat dome. This variation is most likely caused by a combination of factors: (a) Horizontal zonation and lateral variation of the dominant species of plant assemblages (b) Fibric (marginal) peats and hemic to sapric peats associated with type II organic matter (kerogen). Sample organic matter (coal-equivalent kerogen) typing indicates that the relative abundance of phytoclasts and palynomorphs generally supports the organic matter classification obtained by the SRA method. Lateral variations in the peat organic matter types may support the lateral vegetation variation concept. The classification of peat organic matter types (interpreted from visual analyses of palynological slides) occurring from the basin periphery to the mid-section and further towards the basin center yields organic matter of type II to type III and mixed types II to III (coal kerogen-equivalent), respectively.

  6. Approaches to estimating humification indicators for peat

    Directory of Open Access Journals (Sweden)

    M. Klavins

    2008-10-01

    Full Text Available Degree of decomposition is an important property of the organic matter in soils and other deposits which contain fossil carbon. It describes the intensity of transformation, or the humification degree (HD, of the original living organic matter. In this article, approaches to the determination of HD are thoroughly described and 14C dated peat columns extracted from several bogs in Latvia are investigated and compared. A new humification indicator is suggested, namely the quantity of humic substances as a fraction of the total amount of organic matter in the peat.

  7. Status report. KfK contribution to the development of DEMO-relevant test blankets for NET/ITER. Pt. 1: Self-cooled liquid metal breeder blanket. Vol. 1

    International Nuclear Information System (INIS)

    Malang, S.; Reimann, J.; Sebening, H.; Barleon, L.; Bogusch, E.; Bojarsky, E.; Borgstedt, H.U.; Buehler, L.; Casal, V.; Deckers, H.; Feuerstein, H.; Fischer, U.; Frees, G.; Graebner, H.; John, H.; Jordan, T.; Kramer, W.; Krieg, R.; Lenhart, L.; Malang, S.; Meyder, R.; Norajitra, P.; Reimann, J.; Schwenk-Ferrero, A.; Schnauder, H.; Stieglitz, R.; Oschinski, J.; Wiegner, E.

    1991-12-01

    A self-cooled liquid metal breeder blanket for a fusion DEMO-reactor and the status of the development programme is described as a part of the European development programme of DEMO relevant test blankets for NET/ITER. Volume 1 (KfK 4907) contains a summary, Volume 2 (KfK 4908) a more detailed version of the report. Both volumes contain sections on previous studies on self-cooled liquid metal breeder blankets, the reference blanket design for a DEMO-reactor, a typical test blanket design including the ancillary loop system and the building requirements for NET/ITER together with the present status of the associated R and D-programme in the fields of neutronics, magnetohydrodynamics, tritium removal and recovery, liquid metal compatibility and purification, ancillary loop system, safety and reliability. An outlook is given regarding the required R and D-programme for the self-cooled liquid metal breeder blanket prior to tests in NET/ITER and the relevant test programme to be performed in NET/ITER. (orig.) [de

  8. Case-specific comparison of water pollution control alternatives in peat production

    International Nuclear Information System (INIS)

    Savolainen, M.; Kaasinen, A.; Heikkinen, K.; Ihme, R.; Kaemae, T.; Alasaarela, E.

    1996-01-01

    The present practice water pollution control in peat production and the elements of planning were analyzed, the water purification methods were classified and their weaknesses estimated. Furthermore, the cost of the water purification constructions was estimated and their significance for the watercourses evaluated. 54 peat production plans were chosen from the catchment areas of the rivers Iijoki, Siikajoki and Pyhaejoki. The suitability of the chosen water pollution control methods was evaluated on the basis of the plans and, further, on the basis of field surveys. The suitability of the purification methods to practical water pollution control was assessed by making plans for 15 peat mining areas. There is a need to develop the planning and implementation of water pollution control in peat mining. The methods that are used do not always work in the expected way in practice. Despite this planning is compatible with the water protection program and the regulations that are in force. The study gives a good idea of how to update the planning instructions for water pollution control. The accompanying report includes plan for 11 peat mining areas. (orig.)

  9. Carbon leaching from tropical peat soils and consequences for carbon balances

    Directory of Open Access Journals (Sweden)

    Tim Rixen

    2016-07-01

    Full Text Available Drainage and deforestation turned Southeast (SE Asian peat soils into a globally important CO2 source, because both processes accelerate peat decomposition. Carbon losses through soil leaching have so far not been quantified and the underlying processes have hardly been studied. In this study, we use results derived from nine expeditions to six Sumatran rivers and a mixing model to determine leaching processes in tropical peat soils, which are heavily disturbed by drainage and deforestation. Here we show that a reduced evapotranspiration and the resulting increased freshwater discharge in addition to the supply of labile leaf litter produced by re-growing secondary forests increase leaching of carbon by ~200%. Enhanced freshwater fluxes and leaching of labile leaf litter from secondary vegetation appear to contribute 38% and 62% to the total increase, respectively. Decomposition of leached labile DOC can lead to hypoxic conditions in rivers draining disturbed peatlands. Leaching of the more refractory DOC from peat is an irrecoverable loss of soil that threatens the stability of peat-fringed coasts in SE Asia.

  10. Landscape-scale changes in forest canopy structure across a partially logged tropical peat swamp

    Science.gov (United States)

    Wedeux, B. M. M.; Coomes, D. A.

    2015-11-01

    Forest canopy structure is strongly influenced by environmental factors and disturbance, and in turn influences key ecosystem processes including productivity, evapotranspiration and habitat availability. In tropical forests increasingly modified by human activities, the interplay between environmental factors and disturbance legacies on forest canopy structure across landscapes is practically unexplored. We used airborne laser scanning (ALS) data to measure the canopy of old-growth and selectively logged peat swamp forest across a peat dome in Central Kalimantan, Indonesia, and quantified how canopy structure metrics varied with peat depth and under logging. Several million canopy gaps in different height cross-sections of the canopy were measured in 100 plots of 1 km2 spanning the peat dome, allowing us to describe canopy structure with seven metrics. Old-growth forest became shorter and had simpler vertical canopy profiles on deeper peat, consistent with previous work linking deep peat to stunted tree growth. Gap size frequency distributions (GSFDs) indicated fewer and smaller canopy gaps on the deeper peat (i.e. the scaling exponent of Pareto functions increased from 1.76 to 3.76 with peat depth). Areas subjected to concessionary logging until 2000, and illegal logging since then, had the same canopy top height as old-growth forest, indicating the persistence of some large trees, but mean canopy height was significantly reduced. With logging, the total area of canopy gaps increased and the GSFD scaling exponent was reduced. Logging effects were most evident on the deepest peat, where nutrient depletion and waterlogged conditions restrain tree growth and recovery. A tight relationship exists between canopy structure and peat depth gradient within the old-growth tropical peat swamp forest. This relationship breaks down after selective logging, with canopy structural recovery, as observed by ALS, modulated by environmental conditions. These findings improve our

  11. Optimization of seed-blanket type fuel assembly for reduced-moderation water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shelley, Afroza; Shimada, Shoichiro; Kugo, Teruhiko; Okubo, Tsutomu E-mail: okubo@hems.jaeri.go.jp; Iwamura, Takamichi

    2003-10-01

    Parametric studies have been performed for a PWR-type reduced-moderation water reactor (RMWR) with the seed-blanket type fuel assembles to achieve a high conversion ratio, negative void reactivity coefficient and a high burnup by using MOX fuel. From the viewpoint of reactor safety analysis, the fuel temperature coefficients were also studied. From the result of the burnup calculation, it has been seen that ratio of 40-50% of outer blanket in a seed-blanket assembly gives higher conversion ratio compared to the other combination of seed-blanket assembly. And the recommended number of (seed+blanket) layers is 20, in which the number of seed (S) layers is 15 (S15) and blanket (B) layers is 5 (B5). It was found that the conversion ratio of seed-blanket assembly decreases, when they are arranged looks like a flower shape (Hanagara). By the optimization of different parameters, S15B5 fuel assembly with the height of seed of 1000 mmx2, internal blanket of 150 mm and axial blanket of 400 mmx2 is recommended for a reactor of high conversion ratio. In this assembly, the gap of seed fuel rod is 1.0 mm and blanket fuel rod is 0.4 mm. In S15B5 assembly, the conversion ratio is 1.0 and the burnup is 38.18 GWd/t in (seed+internal blanket+outer blanket) region. However, the burnup is 57.45 GWd/t in (seed+internal blanket) region. The cycle length of the core is 16.46 effective full power in month (EFPM) by six batches and the enrichment of fissile Pu is 14.64 wt.%. The void coefficient is +21.82 pcm/%void, however, it is expected that the void coefficient will be negative if the radial neutron leakage is taken into account in the calculation. It is also possible to use S15B5 fuel assembly as a high burnup reactor 45 GWd/t in (seed+internal blanket+outer blanket) region, however, it is necessary to decrease the height of seed to 500 mmx2 to improve the void coefficient. In this reactor, the conversion ratio is 0.97 and void coefficient is +20.81 pcm/%void. The fuel temperature

  12. Aqueous self-cooled blanket concepts for fusion reactors

    International Nuclear Information System (INIS)

    Varsamis, G.; Embrechts, M.J.; Steiner, D.; Deutsch, L.; Gierszewski, P.

    1987-01-01

    A novel aqueous self-cooled blanket (ASCB) concept has been proposed. The water coolant also serves as the tritium breeding medium by dissolving small amounts of lithium compound in the water. The tritium recovery requirements of the ASCB concept may be facilitated by the novel in-situ radiolytic tritium separation technique in development at Chalk River Nuclear Laboratories. In this separation process deuterium gas is bubbled through the blanket coolant. Due to radiation induced processes, the equilibrium constant favors tritium migration to the deuterium gas stream. It is expected that the inherent simplicity of this design will result in a highly reliable, safe and economically attractive breeding blanket for fusion reactors. The available base of relevant information accumulated through water-cooled fission reactor programs should greatly facilitate the R and D effort required to validate the proposed blanket concept. Tests for tritium separation and corrosion compatibility show encouraging results for the feasibility of this concept

  13. Agricultural management impact on physical and chemical functions of European peat soils.

    Science.gov (United States)

    Piayda, Arndt; Tiemeyer, Bärbel; Dettmann, Ullrich; Bechtold, Michel; Buschmann, Christoph

    2017-04-01

    Peat soils offer numerous functions from the global to the local scale: they constitute the biggest terrestrial carbon storage on the globe, form important nutrient filters for catchments and provide hydrological buffer capacities for local ecosystems. Peat soils represent a large share of soils suitable for agriculture in temperate and boreal Europe, pressurized by increasing demands for production. Cultivated peat soils, however, show extreme mineralization rates of the organic substance and turn into hotspots for green house gas emissions, are highly vulnerable to land surface subsidence, soil and water quality deterioration and thus crop failure. The aim of this study is to analyse the impact of past agricultural management on soil physical and chemical functions of peat soils in six European countries. We conducted standardized soil mapping, soil physical/chemical analysis, ground water table monitoring and farm business surveys across 7 to 10 sites in Germany, The Netherlands, Denmark, Estonia, Finland and Sweden. The results show a strong impact of past agricultural management on peat soil functions across Europe. Peat soil under intensive arable land use consistently offer lowest bearing capacities in the upper 10 cm compared to extensive and intensive grassland use, which is a major limiting factor for successful agricultural practice on peat soils. The difference can be explained by root mat stabilization solely, since soil compaction in the upper 25cm is highest under arable land use. A strong decrease of available water capacity and saturated hydraulic conductivity is consequently observed under arable land use, further intensifying hydrological problems like ponding, drought stress and reductions of hydrological buffer capacities frequently present on cultivated peat soils. Soil carbon stocks clearly decrease with increasing land use intensity, showing highest carbon stocks on extensive grassland. This is supported by the degree of decomposition, which

  14. Incorporation of radiometric tracers in peat and implications for estimating accumulation rates

    Energy Technology Data Exchange (ETDEWEB)

    Hansson, Sophia V., E-mail: sophia.hansson@emg.umu.se [Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå (Sweden); Kaste, James M. [Geology Department, The College of William and Mary, Williamsburg, VA 23187 (United States); Olid, Carolina; Bindler, Richard [Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå (Sweden)

    2014-09-15

    Accurate dating of peat accumulation is essential for quantitatively reconstructing past changes in atmospheric metal deposition and carbon burial. By analyzing fallout radionuclides {sup 210}Pb, {sup 137}Cs, {sup 241}Am, and {sup 7}Be, and total Pb and Hg in 5 cores from two Swedish peatlands we addressed the consequence of estimating accumulation rates due to downwashing of atmospherically supplied elements within peat. The detection of {sup 7}Be down to 18–20 cm for some cores, and the broad vertical distribution of {sup 241}Am without a well-defined peak, suggest some downward transport by percolating rainwater and smearing of atmospherically deposited elements in the uppermost peat layers. Application of the CRS age–depth model leads to unrealistic peat mass accumulation rates (400–600 g m{sup −2} yr{sup −1}), and inaccurate estimates of past Pb and Hg deposition rates and trends, based on comparisons to deposition monitoring data (forest moss biomonitoring and wet deposition). After applying a newly proposed IP-CRS model that assumes a potential downward transport of {sup 210}Pb through the uppermost peat layers, recent peat accumulation rates (200–300 g m{sup −2} yr{sup −1}) comparable to published values were obtained. Furthermore, the rates and temporal trends in Pb and Hg accumulation correspond more closely to monitoring data, although some off-set is still evident. We suggest that downwashing can be successfully traced using {sup 7}Be, and if this information is incorporated into age–depth models, better calibration of peat records with monitoring data and better quantitative estimates of peat accumulation and past deposition are possible, although more work is needed to characterize how downwashing may vary between seasons or years. - Highlights: • {sup 210}Pb, {sup 137}Cs, {sup 241}Am and {sup 7}Be, and tot-Pb and tot Hg were measured in 5 peat cores. • Two age–depth models were applied resulting in different accumulation rates

  15. Regulations for the peat production water pollution control; Turvetuotannon vesiensuojeluohjeisto

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen, M.; Heikkinen, K.; Ihme, R. [ed.] [VTT Communities and Infrastructure, Espoo (Finland)

    1996-12-31

    The regulations for peat production water pollution control include the latest information on anti-pollution constructions applicable to peat production including field ditches, sedimentation basins, overland flow areas, forest soil saturation, evaporation basins, chemicalization, detention of runoff and artificial flood plains. Information on subsurface drainage in peat mining is also given. The regulations deal with environmental viewpoints, planning of water protection and information on how to build, use and maintain anti-pollution constructions. Special attention is given to the soil conditions, because they play an important role in the building of different constructions. (orig.) (48 refs.)

  16. Geochemical characteristics of peat from two raised bogs of Germany

    Science.gov (United States)

    Mezhibor, A. M.

    2016-11-01

    Peat has a wide range of applications in different spheres of human activity, and this is a reason for a comprehensive study. This research represents the results of an ICP-MS study of moss and peat samples from two raised bogs of Germany. Because of the wide use of sphagnum moss and peat, determining their geochemical characteristics is an important issue. According to the results obtained, we can resume that the moss samples from Germany are rich in Cu, As, Y, Zr, Nb, and REE. The geochemical composition of the bogs reflects the regional environmental features and anthropogenic influence.

  17. Geotechnical properties of peat soil stabilised with shredded waste tyre chips

    Directory of Open Access Journals (Sweden)

    M.A. Rahgozar

    2016-02-01

    Full Text Available To accommodate major civil engineering projects in or in the vicinity of peatlands, it is essential to stabilise peat deposits. On the other hand, the accumulation of waste tyres in recent decades has caused environmental problems around the world. An effective remedy for both issues is to use scrap tyre material to stabilise problematic peat soils. This article reports an experimental investigation of the effects of adding shredded tyre chips on the stability and bearing capacity of peat soil. Peat soil samples from the Chaghakhor Wetland (Chaharmahal and Bakhtiari Province, Iran were mixed with sand at a constant dosage of 400 kg m-3 and different percentages (0 %, 5 %, 10 %, 15 % and 20 % by weight of shredded tyre chips. The unconfined compressive strength, effective cohesion, angle of internal friction and coefficient of permeability were measured for all of these mixtures. The results showed that adding shredded tyre chips significantly improved the geotechnical properties of the peat soil. The mixture with 10 % shredded tyre chips showed the highest unconfined compressive strength; the one with 15 % tyre chips exhibited the highest ductility; and adding 20 % shredded tyre chips provided the highest values for angle of internal friction, effective cohesion and coefficient of permeability. Scanning Electron Micrographs (SEM showed that the pore spaces in the stabilised peat were mostly filled with sand.

  18. Study on the temperature control mechanism of the tritium breeding blanket for CFETR

    Science.gov (United States)

    Liu, Changle; Qiu, Yang; Zhang, Jie; Zhang, Jianzhong; Li, Lei; Yao, Damao; Li, Guoqiang; Gao, Xiang; Wu, Songtao; Wan, Yuanxi

    2017-12-01

    The Chinese fusion engineering testing reactor (CFETR) will demonstrate tritium self- sufficiency using a tritium breeding blanket for the tritium fuel cycle. The temperature control mechanism (TCM) involves the tritium production of the breeding blanket and has an impact on tritium self-sufficiency. In this letter, the CFETR tritium target is addressed according to its missions. TCM research on the neutronics and thermal hydraulics issues for the CFETR blanket is presented. The key concerns regarding the blanket design for tritium production under temperature field control are depicted. A systematic theory on the TCM is established based on a multiplier blanket model. In particular, a closed-loop method is developed for the mechanism with universal function solutions, which is employed in the CFETR blanket design activity for tritium production. A tritium accumulation phenomenon is found close to the coolant in the blanket interior, which has a very important impact on current blanket concepts using water coolant inside the blanket. In addition, an optimal tritium breeding ratio (TBR) method based on the TCM is proposed, combined with thermal hydraulics and finite element technology. Meanwhile, the energy gain factor is adopted to estimate neutron heat deposition, which is a key parameter relating to the blanket TBR calculations, considering the structural factors. This work will benefit breeding blanket engineering for the CFETR reactor in the future.

  19. AMS measurements of global fallout U-236 and Pu in an ombrotrophic peat profile: evidence for their post depositional migration

    Energy Technology Data Exchange (ETDEWEB)

    Quinto, Francesca; Hrnecek, Erich; Krachler, Michael [European Commission Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Shotyk, William [Department of Renewable Resources, University of Alberta, 839 General Services Building, Edmonton, AB (Canada); Steier, Peter; Winkler, Stephan; Golser, Robin [VERA Laboratory, Faculty of Physics, University of Vienna, Waehringer Strasse 17, A-1090 Vienna (Austria)

    2014-07-01

    U-236, Pu-239, Pu-240, Pu-241 and Pu-242 were analysed in an ombrotrophic peat core representing the last 80 years of atmospheric deposition. The determination of these isotopes at femtogram and attogram levels was possible by using ultra-clean laboratory procedures and accelerator mass spectrometry. Since the Pu isotopic composition characteristic for global fallout, as well as anthropogenic U-236, were identified in peat samples pre-dating the period of atmospheric atom bomb testing, migration of Pu and U within the peat profile is clearly indicated. The vertical profile of the U-236/U-238 isotopic ratio represents the first observation of the U-236 bomb peak in a terrestrial environment. Comparing the abundances of the global fallout derived U-236 and Pu-239 along the peat core, the post depositional migration of plutonium exceeds that of uranium. These results highlight, for the first time, the mobility of Pu and U in a peat bog with implications for their migration in other acidic, organic rich environments.

  20. Bioenergy research programme. Yearbook 1996. Peat and field biomass; Bioenergian tutkimusohjelma. Vuosikirja 1996. Turpeen ja peltobiomassojen tuotantotekniikka

    Energy Technology Data Exchange (ETDEWEB)

    Nikku, P [ed.

    1997-12-01

    The aim of the programme is to increase the use of economically profitable and environmentally sound bioenergy by improving the competitiveness of present peat and wood fuels. Research and development projects will also develop new economically competitive biofuels, new equipment and methods for production, handling and utilisation of biofuels. The total funding for 1996 was 27.3 million FIM and the number of projects 63. The number of projects concerning peat production was 7 and that of field biomass projects 4. Results of the projects carried out in 1996 are presented in this publication. The development target in the research area of peat production is to improve the competitiveness of peat by reducing the production costs by 20 % (by 5-6 FIM/MWh) from the level of 1992, and to reduce the environmental impacts. The target of the research area of peat production is possible to achieve if the sub-targets are achieved. The production costs are reduced by 5 % if the width of the production field is increased from 20 m to 60 m, by 8 % if the degree of utilisation of solar energy is increased from 30 % to 40 %, by 6.5 % if the value of peat remaining on the cutover field is reduced from 3 000 MWh to 1 500 MWh, by 3 % if light and fireproof machines are developed, and by 3 % if combined peat and wood harvesting is applied. The production costs will be reduced by 24 % if the different sub-targets are achieved. In this programme no common target for the field biomass projects was set. Field biomass projects are mainly funded by the Finnish Ministry of Agriculture and Forestry. Most of the research projects were completed in 1996. (orig.)

  1. Conceptual design and analysis of the helium cooled solid breeder blanket for CFETR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hongli, E-mail: hlchen1@ustc.edu.cn; Li, Min; Lv, Zhongliang; Zhou, Guangming; Liu, Qianwen; Wang, Shuai; Wang, Xiaoliang; Zheng, Jie; Ye, Minyou

    2015-10-15

    Highlights: • A helium cooled solid blanket was proposed as a candidate blanket concept for CFETR. • Material selection, basic structure and gas flow scheme of the blanket were introduced. • A series of performance analyses for the blanket were summarized. - Abstract: To bridge the gap between ITER and DEMO and to realize the fusion energy in China, a fusion device Chinese Fusion Engineering Test Reactor (CFETR) was proposed and is being designed mainly to demonstrate 50–200 MW fusion power, 30–50% duty time factor, tritium self-sustained. Because of the high demand of tritium production and the realistic engineering consideration, the design of tritium breeding blanket for CFETR is a challenging work and getting special attention. As a blanket candidate, a helium cooled solid breeder blanket has been designed with the emphasis on conservative design and realistic blanket technology. This paper introduces the basic blanket scheme, including the material selection, structural design, cooling scheme and purge gas flow path. In addition, some results of neutronics, thermal-hydraulic and stress analysis are presented.

  2. Overview of the Sustainable Uses of Peat Soil in Malaysia with Some Relevant Geotechnical Assessments

    OpenAIRE

    Rashidah Adon; Ismail Bakar; Devapriya Chitral Wijeyesekera; Adnan Zainorabidin

    2013-01-01

    Peat soil is an important ecosystem that provides a significant contribution to the global climate stability. In Malaysia, peat soils are considered as a soil with little economic benefit, apart from it being used for agricultural activity. The total world coverage of peat soil is about thirty million hectares with Canada and Russia having the largest distribution of peat (Zainorabiddin,2010). More than sixty percent of the world’s tropical peat lands are found in South-East Asia (Lette,2006...

  3. Continuous fine pattern formation by screen-offset printing using a silicone blanket

    Science.gov (United States)

    Nomura, Ken-ichi; Kusaka, Yasuyuki; Ushijima, Hirobumi; Nagase, Kazuro; Ikedo, Hiroaki; Mitsui, Ryosuke; Takahashi, Seiya; Nakajima, Shin-ichiro; Iwata, Shiro

    2014-09-01

    Screen-offset printing combines screen-printing on a silicone blanket with transference of the print from the blanket to a substrate. The blanket absorbs organic solvents in the ink, and therefore, the ink does not disperse through the material. This prevents blurring and allows fine patterns with widths of a few tens of micrometres to be produced. However, continuous printing deteriorates the pattern’s shape, which may be a result of decay in the absorption abilities of the blanket. Thus, we have developed a new technique for refreshing the blanket by substituting high-boiling-point solvents present on the blanket surface with low-boiling-point solvents. We analyse the efficacy of this technique, and demonstrate continuous fine pattern formation for 100 screen-offset printing processes.

  4. Continuous fine pattern formation by screen-offset printing using a silicone blanket

    International Nuclear Information System (INIS)

    Nomura, Ken-ichi; Kusaka, Yasuyuki; Ushijima, Hirobumi; Nagase, Kazuro; Ikedo, Hiroaki; Mitsui, Ryosuke; Takahashi, Seiya; Nakajima, Shin-ichiro; Iwata, Shiro

    2014-01-01

    Screen-offset printing combines screen-printing on a silicone blanket with transference of the print from the blanket to a substrate. The blanket absorbs organic solvents in the ink, and therefore, the ink does not disperse through the material. This prevents blurring and allows fine patterns with widths of a few tens of micrometres to be produced. However, continuous printing deteriorates the pattern’s shape, which may be a result of decay in the absorption abilities of the blanket. Thus, we have developed a new technique for refreshing the blanket by substituting high-boiling-point solvents present on the blanket surface with low-boiling-point solvents. We analyse the efficacy of this technique, and demonstrate continuous fine pattern formation for 100 screen-offset printing processes. (paper)

  5. Distribution of sulphur and trace elements in peat. [Literature survey with some additional sulphur analyses

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen, S; Karhu, M

    1981-01-01

    A survey on the literature and contemporary research was made on peat sulphur and trace element studies. Marked variance between different peatlands and peat types has been noted. The available information is still inadequate for generalizations or statistical analysis mainly due to methodological variations and temporal and spatial variations in results. At the moment, the criteria applied in peatland inventories and evaluations are inadequate with respect to peat quality determinations. To some extent the quality of fuel peat should be determined in a mire inventory prior to peatland utilization. The areas over sulphide clay and some sulphate depositions may considerably increase the peat sulphur content. A proposal has been made to include the sulphur content monitoring in the cases where it exceeds 0.3 per cent. The trace elements may also bring about an increase in peat emissions if the deepest peat layers or polluted layers are burnt. The most important elements in this respect are Al, Fe, Mn, Pb, Zn, V, Ni, Hg, Cu, Cr, as well as As and U. The first ten because of the relatively high concentrations and last two because of pollution or toxocity and ore deposit factors. The peat hydrogen ion concentration has a positive correlation with copper and vanadium. The correlation is positive with the cobalt and nickel contents when the pH is low, and negative at a higher pH. A general peat type correlation shows maximum trace element contents in basal Carex peats with subsoil effects. The peat ash content and the Ti, Pb, V, Cr, Ni and S contents have positive correlations.

  6. Peat briquette as an alternative to cooking fuel: A techno-economic viability assessment in Rwanda

    International Nuclear Information System (INIS)

    Hakizimana, Jean de Dieu K.; Kim, Hyung-Taek

    2016-01-01

    Commercialization of peat briquetting technology was analyzed to know whether the technology is economically viable or not compared to commercialization of charcoal. The investigation of economic viability was assessed from raw-peat production to briquetting technologies. The briquettes were made by naturally dried of peat from Bisika, Bahimba, Ndongozi and Nyirabirande bogs, through a rotary pulverizer and a briquette press; they were carbonized into furnace at 450 °C to reduce its health effects. The burning rate of peat briquettes made varied from 0.178 kg/hour to 0.222 kg/hour. Ash content varying between 3 and 7.2 percent was also observed. The results showed that peat briquettes can be sold at USD0.18 per unit, with a total NPV of USD17.2 million. However, as the NPV tends to be zero, the selling price would be approximately USD0.155 per briquette. Monthly charcoal expenses were about USD23.20/household compared to a per-household cost of USD16.20/month of peat briquettes consumption; the supplanting of charcoal by peat briquettes would help the average Rwandan household reduce its monthly expenses by 30 percent. Peat briquettes utilization as cooking fuel in Rwanda could save 0.05 percent of CO_2 and more than 99 percent of CH_4 emissions, compared to charcoal emissions. - Highlights: • A technical process for peat production and peat briquetting. • An efficiency test of carbonized briquettes. • Commercialization of peat briquettes is compared to commercialization of charcoal. • Opportunities for greenhouse gas emissions reduction.

  7. A statistical approach to determining the uncertainty of peat thickness

    Directory of Open Access Journals (Sweden)

    J. Torppa

    2011-06-01

    Full Text Available This paper presents statistical studies of peat thickness to define its expected maximum variation (∆dm(∆r as a function of separation distance Δr. The aim was to provide an estimate of the observational uncertainty in peat depth due to positioning error, and the prediction uncertainty of the computed model. The data were GPS position and ground penetrating radar depth measurements of six mires in different parts of Finland. The calculated observational uncertainty for Finnish mires in general caused, for example, by a 20 m positioning error, is 43 cm in depth with 95 % confidence. The peat depth statistics differed among the six mires, and it is recommended that the mire specific function ∆dm(∆r is defined for each individual mire to obtain the best estimate of observational uncertainty. Knowledge of the observational error and function ∆dm(∆r should be used in peat depth modelling for defining the uncertainty of depth predictions.

  8. Construction of Buildings on Peat: Case Studies and Lessons Learned

    Directory of Open Access Journals (Sweden)

    Mahmod Ali Abdul-Wadoud

    2016-01-01

    Full Text Available Building construction on soft soils including on peat has many challenges and difficulties. The failed and deteriorated buildings have a big impact on the community. The IConCEES International Workshop 2015 which was conducted on October 2015 convened as a joint venture between Universiti Tun Hussein Onn Malaysia (UTHM and the University College of Technology Sarawak (UCTS. The aim was to invite regional experts from academia and the industry to formally present and discuss the various construction problems encountered when working with peat. The discussions were divided into two divisions; infrastructure and building construction. This paper discusses the outcomes of the workshop and focuses on the factors and relevant challenges when constructing buildings on peat. The experts have discussed regulatory and construction issues including: drainage issues, site investigation practices, monitoring and construction guidelines. A few suggestions were outlined as a remedy to these problems and to better assist the peat practitioner at work.

  9. The evolution of US helium-cooled blankets

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Schultz, K.R.; Cheng, E.T.

    1991-01-01

    This paper reviews and compares four helium-cooled fusion reactor blanket designs. These designs represent generic configurations of using helium to cool fusion reactor blankets that were studied over the past 20 years in the United States of America (US). These configurations are the pressurized module design, the pressurized tube design, the solid particulate and gas mixture design, and the nested shell design. Among these four designs, the nested shell design, which was invented for the ARIES study, is the simplest in configuration and has the least number of critical issues. Both metallic and ceramic-composite structural materials can be used for this design. It is believed that the nested shell design can be the most suitable blanket configuration for helium-cooled fusion power and experimental reactors. (orig.)

  10. Li2O-pebble type tritium breeding blanket for fusion experimental reactor, 1

    International Nuclear Information System (INIS)

    Tone, Tatsuzo; Iida, Hiromasa; Tanaka, Yoshihisa

    1984-01-01

    The fusion experimental reactor is the next stage device in Japan, which is planned to be constructed following the critical plasma experimental device JT-60 being constructed at present. The breeding blanket installed in nuclear fusion reactors is one of most important structures, and it is required to satisfy the fundamental performance of producing and continuously recovering tritium as the nuclear fusion fuel, and other requirement in good coordination. The Li 2 O pebble type breeding blanket that Kawasaki Heavy Industries Ltd. has examined is the concept for resolving the problems of the mass transfer and thermal stress cracking of Li 2 O, which are important in blanket design. In this paper, the concept and characteristics of this breeding blanket are discussed from the viewpoint of the breeding and continuous recovery of tritium, the ease of manufacture and the maintenance of soundness. The breeding blanket is composed of breeding region, tritium purge region, cooling region, plasma stabilizing conductors and blanket container. Li 2 O is excellent in its tritium breeding performance and heat conductivity. The functions required for the breeding blanket, the fundamental structure, the examples of breeding blanket concept, the selection of breeding blanket concept, the characteristics of Li 2 O pebble type blanket and its future prospect are described. (Kako, I.)

  11. Spatial variation of peat soil properties in the oil-producing region of northeastern Sakhalin

    Science.gov (United States)

    Lipatov, D. N.; Shcheglov, A. I.; Manakhov, D. V.; Zavgorodnyaya, Yu. A.; Rozanova, M. S.; Brekhov, P. T.

    2017-07-01

    Morphology and properties of medium-deep oligotrophic peat, oligotrophic peat gley, pyrogenic oligotrophic peat gley, and peat gley soils on subshrub-cotton grass-sphagnum bogs and in swampy larch forests of northeastern Sakhalin have been studied. Variation in the thickness and reserves of litters in the studied bog and forest biogeocenoses has been analyzed. The profile distribution and spatial variability of moisture, density, ash, and pHKCl in separate groups of peat soils have been described. The content and spatial variability of petroleum hydrocarbons have been considered in relation to the accumulation of natural bitumoids by peat soils and the technogenic pressing in the oil-producing region. Variation of each parameter at different distances (10, 50, and 1000 m) has been estimated using a hierarchical sampling scheme. The spatial conjugation of soil parameters has been studied by factor analysis using the principal components method and Spearman correlation coefficients. Regression equations have been proposed to describe relationships of ash content with soil density and content of petroleum hydrocarbons in peat horizons.

  12. Evaluation of potential blanket concepts for a Demonstration Tokamak Hybrid Reactor

    International Nuclear Information System (INIS)

    Chapin, D.L.; Chi, J.W.H.; Kelly, J.L.

    1978-01-01

    An evaluation has been made of several different blanket concepts for use in a near-term Demonstration Tokamak Hybrid Reactor (DTHR), whose main objective would be to produce a significant amount of fissile fuel while demonstrating the feasibility of the tokamak hybrid reactor concept. The desirability of a simple design using proven technology plus a proliferation resistant fuel cycle led to the selection of a low temperature and pressure water-cooled, zircaloy clad ThO 2 blanket concept to breed 233 U. The nuclear performance and thermal-hydraulics characteristics of the blanket were evaluated to arrive at a consistent design. The blanket was found to be feasible for producing a significant amount of fissile fuel even with the limited operating conditions and blanket coverage in the DTHR

  13. Towards sustainable ecological networks of peat bogs in central Russia; development of local environmental action program (LEAP) as a practical tool for protection and restoration of peat bogs in Egorievsk sub region

    NARCIS (Netherlands)

    Butovsky, R.O.; Reijnen, R.; Bondartchuk, E.A.; Otchagov, D.M.; Melik-Bagdasarov, E.M.

    2001-01-01

    In central and northern Meshera the habitats for many characteristic peat bog species now show a very fragmented pattern. As a result, the potential for viable populations of characteristic peat bog species has decreased considerably. Peat-mining and other human influences are the most important

  14. The transpiration cooled first wall and blanket concept

    International Nuclear Information System (INIS)

    Barleon, Leopold; Wong, Clement

    2002-01-01

    To achieve high thermal performance at high power density the EVOLVE concept was investigated under the APEX program. The EVOLVE W-alloy first wall and blanket concept proposes to use transpiration cooling of the first wall and boiling or vaporizing lithium (Li) in the blanket zone. Critical issues of this concept are: the Magnetohydrodynamic (MHD) pressure losses of the Li circuit, the evaporation through a capillary structure and the needed superheating of the Li at the first wall and blanket zones. Application of the transpiration concept to the blanket region results in the integrated transpiration cooling concept (ITCC) with either toroidal or poloidal first wall channels. For both orientations the routing of the liquid Li and the Li vapor has been modeled and the corresponding pressure losses have been calculated by varying the width of the supplying slot and the capillary diameter. The concept works when the sum of the active and passive pumping head is higher than the total system pressure losses and when the temperature at the inner side of the first wall does not override the superheating limit of the coolant. This cooling concept has been extended to the divertor design, and the removal of a surface heat flux of up to 10 MW/m 2 appears to be possible, but this paper will focus on the transpiration cooled first wall and blanket concept assessment

  15. Ecology of Coom Rigg Moss, Northumberland. I. Stratigraphy and present vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, S B

    1964-01-01

    A description is given of Coom Rigg Moss, a bog in Northumberland. Evidence from peat stratigraphy and pollen analysis distinguishes two main types of peat profile, a raised bog type and a blanket bog type. It is shown that fen peat formation began in hollows (zone VI) then became covered with alder-birch carr in zone VIIa and that the whole area was covered with peat by the beginning of zone VIIb. These conditions have produced a bog system at the present time that can best be described as centres of raised bog development now united by blanket peat formation. The vegetation of the bog surface is described and it is shown that two types of vegetation occur, one containing more Sphagnum magnum magellanicum than S. papillosum, confined to areas where it is subjected to a flushing effect, and the other containing more S. papillosum than S. magellanicum, being more typical of the greater part of the bog surface. It is shown that plants of phragmites still growing on the bog surface are relics from previous vegetation and that they have gradually been restricted in their distribution. It suggested that relative isolation and freedom from damage by grazing, burning and drainage have allowed this site to continue in a state of active peat accumulation.

  16. Organic Matter Transformation in the Peat Column at Marcell Experimental Forest: Humification and Vertical Stratification

    Energy Technology Data Exchange (ETDEWEB)

    Tfaily, Malak [Florida State University, Tallahassee; Cooper, Bill [Florida State University, Tallahassee; Kostka, [Georgia Institute of Technology, Atlanta; Chanton, Patrick R [ORNL; Schadt, Christopher Warren [ORNL; Hanson, Paul J [ORNL; Iversen, Colleen M [ORNL; Chanton, Jeff P [ORNL

    2014-01-01

    A large-scale ecosystem manipulation (Spruce and Peatland Responses under Climatic and Environmental Change, SPRUCE) is being constructed in the Marcell Experimental Forest, Minnesota, USA, to determine the effects of climatic forcing on ecosystem processes in northern peatlands. Prior to the initiation of the manipulation, we characterized the solid-phase peat to a depth of 2 meters using a variety of techniques, including peat C:N ratios, 13C and 15N isotopic composition, Fourier Transform Infrared (FT IR), and 13C Nuclear Magnetic Resonance spectroscopy (13C NMR). FT IR determined peat humification-levels increased rapidly between and 75 cm, indicating a highly reactive zone. We observed a rapid drop in the abundance of O-alkyl-C, carboxyl-C, and other oxygenated functionalities within this zone and a concomitant increase in the abundance of alkyl- and nitrogen-containing compounds. Below 75-cm, minimal change was observed except that aromatic functionalities accumulated with depth. Incubation studies revealed the highest methane production rates and greatest CH4:CO2 ratios within this and 75 cm zone. Hydrology and surface vegetation played a role in belowground carbon cycling. Radiocarbon signatures of microbial respiration products in deeper porewaters resembled the signatures of dissolved organic carbon rather than solid phase peat, indicating that more recently photosynthesized organic matter fueled the bulk of subsurface microbial respiration. Oxygen-containing functionalities, especially O-alkyl-C, appear to serve as an excellent proxy for soil decomposition rate, and in addition should be a sensitive indicator of the response of the solid phase peat to the climatic manipulation.

  17. Neutronic investigation and activation calculation for CFETR HCCB blankets

    Science.gov (United States)

    Shuling, XU; Mingzhun, LEI; Sumei, LIU; Kun, LU; Kun, XU; Kun, PEI

    2017-12-01

    The neutronic calculations and activation behavior of the proposed helium cooled ceramic breeder (HCCB) blanket were predicted for the Chinese Fusion Engineering Testing Reactor (CFETR) design model using the MCNP multi-particle transport code and its associated data library. The tritium self-sufficiency behavior of the HCCB blanket was assessed, addressing several important breeding-related arrangements inside the blankets. Two candidate first wall armor materials were considered to obtain a proper tritium breeding ratio (TBR). Presentations of other neutronic characteristics, including neutron flux, neutron-induced damages in terms of the accumulated dpa and helium production were also conducted. Activation, decay heat levels and contact dose rates of the components were calculated to estimate the neutron-induced radioactivity and personnel safety. The results indicate that neutron radiation is efficiently attenuated and slowed down by components placed between the plasma and toroidal field coil. The dominant nuclides and corresponding isotopes in the structural steel were discussed. A radioactivity comparison between pure beryllium and beryllium with specific impurities was also performed. After a millennium cooling time, the decay heat of all the concerned components and materials is less than 1 × 10-4 kW, and most associated in-vessel components qualify for recycling by remote handling. The results demonstrate that acceptable hands-on recycling and operation still require a further long waiting period to allow the activated products to decay.

  18. A carbon fibre composite (CFC Byelorussian peat corer

    Directory of Open Access Journals (Sweden)

    L.G. Franzén

    2009-01-01

    Full Text Available The design specification, development and manufacture of a Byelorussian (Russian peat corer constructed from carbon fibre composite (CFC are described. The availability of this new composite material introduces new possibilities for constructing field instruments that are as strong as, or stronger than, equipment made from steel and other metals. One advantage is a significant weight reduction. A 10.5 metre coring set in standard stainless and soft steel weighs around 16 kg, whereas the total weight of a similar CFC set is 5.2 kg, giving a weight reduction of almost 70%. The CFC sample chamber is 500 mm long with internal diameter 65 mm, and so contains almost twice the volume of peat that can be collected with a standard 45 mm diameter steel corer. The diameter of the rods is 30 mm, which improves ergonomics, and the CFC has better thermic properties for winter use. Another advantage is that the contamination of samples (notably by chromium and nickel associated with the use of steel corers is eliminated. The CFC sampler works well in soft peats such as Sphagnum and Carex types. It is less suitable for little-decomposed fibrous and forest peats (e.g. Polytrichum type and those containing hardwood remains, especially in the more compacted bottom layers. It should be totally satisfactory for organic lake sediments, but probably not for stiff and coarse mineral deposits.

  19. High resolution 14C dating of surface peat using the AMS technique

    International Nuclear Information System (INIS)

    Tolonen, K.; Possnert, G.; Jungner, H.; Sonninen, E.; Alm, J.

    1992-01-01

    In an AMS (Accelerator Mass Spectrometric) determination of 14 C from moss-increment dated samples from a Sphagnum fuscum hummock, a clear peak representing the time of high 14 C activity in the atmosphere due to nuclear bomb tests was found. The C-14 activities in the peat profile at deeper levels, corresponding to the period down to 1600 Bp, showed similar variations as the atmospheric values. The time scale obtained from radiocarbon dating fitted well with results from moss-increment counting, pollen analysis and dendrochronological dating of a fire horizon. Using the bomb layers and refixing into growing peat was estimated. The fraction of soil carbon dioxide taken up by the contemporary Sphagnum Sward was thus found to be in the order of 20 %. (orig.). (15 refs., 5 figs., 2 tabs.)

  20. Greenhouse gas efflux from an impacted Malaysian tropical peat swamp (Invited)

    Science.gov (United States)

    Waldron, S.; Vihermaa, L. E.; Evers, S.; Garnett, M.; Newton, J.; Padfield, R.

    2013-12-01

    Tropical peatlands constitute ~11% of global peatland area and ~12% of the global peat C pool. Malaysia alone contains 10% of tropical peats. Due to rising global demands for food and biofuels, SE-Asia peat swamp forest ecosystems are threatened by increasing amounts of drainage, fire and conversion to plantation. These processes can change the GHG emissions and thus net ecosystem C balance. However, in comparison to temperate and boreal peatlands, there is a lack of data on terrestrial-aquatic-atmospheric carbon transfer from tropical peatlands, both those that are little disturbed and those facing anthropogenic pressures. Lateral transport of soil-respired carbon, and fluvial respiration or UV-oxidation of terrestrial DOC primes atmospheric carbon dioxide efflux. We now know that DOC lost from disturbed tropical peat swamp forests can be centuries to millennia old and originates deep within the peat column - this carbon may fuel efflux of old carbon dioxide and so anthropogenic land-use change renders the older, slower carbon cycles shorter and faster. Currently we have no knowledge of how significant ';older-slower' terrestrial-aquatic-atmospheric cycles are in disturbed tropical peatlands. Further, in some areas for commercial reasons, or by conservation bodies trying to minimise peat habitat loss, logged peats have been left to regenerate. Consequently, unpicking the legacy of multiple land uses on magnitude, age and source of GHG emissions is challenging but required to support land management decisions and projections of response to a changing climate. Here, we present the results of our first field campaign in July 2013 to the Raja Musa and Sungai Karang Peat Swamp Forest Reserves in North Selangor, Malaysia. This is one of Malaysia's largest oceanic peat swamps, and has been selectively logged and drained for 80 years, but is now subject to a 30 year logging ban to aid forest regeneration and build up wood stocks. From sites subject to different land use

  1. Fusion blanket high-temperature heat transfer

    International Nuclear Information System (INIS)

    Fillo, J.A.

    1983-01-01

    Deep penetration of 14 MeV neutrons makes two-temperature region blankets feasible. A relatively low-temperature (approx. 300 0 C) metallic structure is the vacuum/coolant pressure boundary, while the interior of the blanket, which is a simple packed bed of nonstructural material, operates at very high temperatures (>1000 0 C). The water-cooled shell structure is thermally insulated from the steam-cooled interior. High-temperature steam can dramatically increase the efficiency of electric power generation, as well as produce hydrogen and oxygen-based synthetic fuels at high-efficiency

  2. Tritium behaviour in ceramic breeder blankets

    International Nuclear Information System (INIS)

    Miller, J.M.

    1989-01-01

    Tritium release from the candidate ceramic materials, Li 2 O, LiA10 2 , Li 2 SiO 3 , Li 4 SiO 4 and Li 2 ZrO 3 , is being investigated in many blanket programs. Factors that affect tritium release from the ceramic into the helium sweep gas stream include operating temperature, ceramic microstructure, tritium transport and solubility in the solid. A review is presented of the material properties studied and of the irradiation programs and the results are summarized. The ceramic breeder blanket concept is briefly reviewed

  3. Feasibility study of fusion breeding blanket concept employing graphite reflector

    International Nuclear Information System (INIS)

    Cho, Seungyon; Ahn, Mu-Young; Lee, Cheol Woo; Kim, Eung Seon; Park, Yi-Hyun; Lee, Youngmin; Lee, Dong Won

    2015-01-01

    Highlights: • A Helium-Cooled Ceramic Reflector (HCCR) breeding blanket concept adopts graphite as a reflector material by reducing the amount of beryllium multiplier. • Its feasibility was investigated in view point of the nuclear performance as well as material-related issues. • A nuclear analysis is performed under the fusion reactor condition to address the feasibility of graphite reflector in breeding blanket. • Also, the chemical stability of the graphite is investigated considering the chemical stability under accident conditions. • In conclusion, the adaptation of graphite reflector in breeding blanket is intrinsically safe and plausible under fusion reactor condition. - Abstract: To obtain high tritium breeding performance with limited blanket thickness, most of solid breeder blanket concepts employ a combination of lithium ceramic as a breeder and beryllium as a multiplier. In this case, considering that huge amount of beryllium are needed in fusion power plants, its handling difficulty and cost can be a major factor to be accounted for commercial use. Korea has proposed a Helium-Cooled Ceramic Reflector (HCCR) breeding blanket concept relevant to fusion power plants. Here, graphite is used as a reflector material by reducing the amount of beryllium multiplier. Its feasibility has been investigated in view point of the nuclear performance as well as material-related issues. In this paper, a nuclear analysis is performed under the fusion reactor condition to address the feasibility of graphite reflector in breeding blanket, considering tritium breeding capability and neutron shielding and activation aspects. Also, the chemical stability of the graphite is investigated considering the chemical stability under accident conditions, resulting in that the adaptation of graphite reflector in breeding blanket is intrinsically safe and plausible under fusion reactor condition.

  4. Feasibility study of fusion breeding blanket concept employing graphite reflector

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seungyon, E-mail: sycho@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Ahn, Mu-Young [National Fusion Research Institute, Daejeon (Korea, Republic of); Lee, Cheol Woo; Kim, Eung Seon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Yi-Hyun; Lee, Youngmin [National Fusion Research Institute, Daejeon (Korea, Republic of); Lee, Dong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Highlights: • A Helium-Cooled Ceramic Reflector (HCCR) breeding blanket concept adopts graphite as a reflector material by reducing the amount of beryllium multiplier. • Its feasibility was investigated in view point of the nuclear performance as well as material-related issues. • A nuclear analysis is performed under the fusion reactor condition to address the feasibility of graphite reflector in breeding blanket. • Also, the chemical stability of the graphite is investigated considering the chemical stability under accident conditions. • In conclusion, the adaptation of graphite reflector in breeding blanket is intrinsically safe and plausible under fusion reactor condition. - Abstract: To obtain high tritium breeding performance with limited blanket thickness, most of solid breeder blanket concepts employ a combination of lithium ceramic as a breeder and beryllium as a multiplier. In this case, considering that huge amount of beryllium are needed in fusion power plants, its handling difficulty and cost can be a major factor to be accounted for commercial use. Korea has proposed a Helium-Cooled Ceramic Reflector (HCCR) breeding blanket concept relevant to fusion power plants. Here, graphite is used as a reflector material by reducing the amount of beryllium multiplier. Its feasibility has been investigated in view point of the nuclear performance as well as material-related issues. In this paper, a nuclear analysis is performed under the fusion reactor condition to address the feasibility of graphite reflector in breeding blanket, considering tritium breeding capability and neutron shielding and activation aspects. Also, the chemical stability of the graphite is investigated considering the chemical stability under accident conditions, resulting in that the adaptation of graphite reflector in breeding blanket is intrinsically safe and plausible under fusion reactor condition.

  5. Progress on DEMO blanket attachment concept with keys and pins

    International Nuclear Information System (INIS)

    Vizvary, Zsolt; Iglesias, Daniel; Cooper, David; Crowe, Robert; Riccardo, Valeria

    2015-01-01

    Highlights: • DEMO blanket attachment system with keys and pins (without using bolts). • Blanket segments are preloaded by progressively designed springs. • Blanket back plate flexibility has a major impact on spring design. • Mechanical analysis of other components indicates no unresolvable issues. • Thermal analysis indicates acceptable temperatures for the support system. - Abstract: The blanket attachment has to cope with gravity, thermal and electromagnetic loads, also it has to be installed and serviced by remote handling. Pre-stressed components suffer from stress relaxation in irradiated environments such as DEMO. To circumvent this problem pre-stressed component should be either avoided or shielded, and where possible keys and pins should be used. This strategy has been proposed for the DEMO multi-module segments (MMS). The blanket segments are held by two tapered keys each, designed to allow thermal expansions while providing contact with the vacuum vessel and to resist the poloidal and radial moments the latter being dominant at 9.1 MNm inboard and 15 MNm outboard. On the top of the blanket segment there is a pin which provides vertical support. At the bottom another vertical support has to lock them in position after installation and manage the pre-load on the segments. The pre-load is required to deal with the electromagnetic loads during disruption. This is provided by a set of springs, which require shielding as they are preloaded. These are sized to cope with the force (3 MN inboard, 1.4 MN outboard) due to halo currents and the toroidal moment which can reverse. Calculations show that the flexibility of the blanket segment itself plays a significant role in defining the required support system. The blanket segment acts as a preloaded spring and it has to be part of the attachment design as well.

  6. Nuclear characteristics of D-D fusion reactor blankets, (1)

    International Nuclear Information System (INIS)

    Nakashima, Hideki; Ohta, Masao; Seki, Yasushi.

    1977-01-01

    Fusion reactors operating on the deuterium (D-D) cycle are considered promising for their freedom from tritium breeding in the blanket. In this paper, neutronic and photonic calculations are undertaken covering several blanket models of the D-D fusion reactor, using presently available data, with a view to comparing the nuclear characteristics of these models, in particular, the nuclear heating rates and their spatial distributions. Nine models are taken up for the study, embodying various combinations of coolant, blanket, structural and reflector materials. About 10 MeV is found to be a typical value for the total nuclear energy deposition per source neutron in the models considered here. The realization of high energy gain is contingent upon finding a favorable combination of blanket composition and configuration. The resulting implications on the thermal design aspect are briefly discussed. (auth.)

  7. Systematic methodology for estimating direct capital costs for blanket tritium processing systems

    International Nuclear Information System (INIS)

    Finn, P.A.

    1985-01-01

    This paper describes the methodology developed for estimating the relative capital costs of blanket processing systems. The capital costs of the nine blanket concepts selected in the Blanket Comparison and Selection Study are presented and compared

  8. Immobilization of Lead from Pb-Contaminated Soil Amended with Peat Moss

    Directory of Open Access Journals (Sweden)

    Seul-Ji Lee

    2013-01-01

    Full Text Available Immobilization of lead (Pb using soil amendments can reduce Pb toxicity and bioavailability in soil. This study evaluated Pb immobilization in a Pb-contaminated soil by using peat moss through various tests. The Pb-contaminated soil (2000 mg Pb·kg−1 was amended with 1%, 5%, and 10% of peat moss to immobilize Pb in the soil. The immobilization properties of Pb in the contaminated soil were evaluated by a column leaching experiment, a microcosm test, and a batch incubation test. Peat moss significantly reduced the Pb leaching in all of the experiments and more effectively reduced mobility and toxicity of Pb in the column leaching and microcosm tests than bioavailability in the batch incubation test. The immobilized lead from the soils amended with 1%, 5%, and 10% of peat moss was 37.9%, 87.1%, and 95.4% from the column leaching test, 18.5%, 90.9%, and 96.4% from the microcosm test, and 2.0%, 36.9%, and 57.9% from the NH4NO3 extraction method, respectively, indicating that peat moss can be effectively used for the remediation of Pb-contaminated soil.

  9. The effects of peat mining on fluvial fish and their environment

    International Nuclear Information System (INIS)

    Laine, A.; Sutela, T.; Heikkinen, K.; Karvonen, K.; Huhta, A.; Mutka, T.; Lappalainen, A.

    1996-01-01

    The effects of peat mining on the quality of the stream bed, benthic fauna and fluvial fish were studied at rifles of the Rivers Iijoki and Kiiminkijoki in 1991-94. The amount of organic matter that accumulated on the bottom increased below peat mining areas. Some shifts were seen also in the composition and density of the benthic fauna. In spite of the increase in the total density of the benthic fauna, the growth of the young salmonids was weaker in the riffles that were affected by peat production. Especially large-sized caddish fly larvae were eaten less and also the stomachs of one- year-old salmon were on the average less full there than in the reference areas. Fish densities varied a lot, and no statistical differences were observed between the loaded and the reference areas. The survival of the stocked 0+ salmon fry, however, decreased along with increasing load from peat mining areas. Below the peat mining areas, also the mortality of the incubated brown trout roe was higher than in the reference areas, most probably because of the siltage of the river bottom

  10. A methodology for accident analysis of fusion breeder blankets and its application to helium-cooled lead–lithium blanket

    International Nuclear Information System (INIS)

    Panayotov, Dobromir; Poitevin, Yves; Grief, Andrew; Trow, Martin; Dillistone, Michael

    2016-01-01

    'Fusion for Energy' (F4E) is designing, developing, and implementing the European Helium-Cooled Lead-Lithium (HCLL) and Helium-Cooled Pebble-Bed (HCPB) Test Blanket Systems (TBSs) for ITER (Nuclear Facility INB-174). Safety demonstration is an essential element for the integration of these TBSs into ITER and accident analysis is one of its critical components. A systematic approach to accident analysis has been developed under the F4E contract on TBS safety analyses. F4E technical requirements, together with Amec Foster Wheeler and INL efforts, have resulted in a comprehensive methodology for fusion breeding blanket accident analysis that addresses the specificity of the breeding blanket designs, materials, and phenomena while remaining consistent with the approach already applied to ITER accident analyses. Furthermore, the methodology phases are illustrated in the paper by its application to the EU HCLL TBS using both MELCOR and RELAP5 codes.

  11. Physical parameters and accumulation rates in peat in relation to the climate during the last 150 years

    Energy Technology Data Exchange (ETDEWEB)

    Borgmark, Anders [Dept. of Physical Geography and Quaternary Geology, Stockholm Univ. (Sweden)

    2006-12-15

    The safety assessment made by SKB (SR 97) states that radionuclides can be accumulated in higher amounts in peatlands than in other recipients. Therefore is knowledge about the nature and properties of peat very important. Here is the decay of peat and the accumulation rate of the most important elements of peat examined further. Two ombrotrophic peat bogs located in Uppland have been investigated in order to evaluate the influences of climate on the accumulation of carbon and nitrogen. Peat humification, content of carbon and nitrogen has been used for interpretation of peat forming processes. The long temperature and precipitation records from Uppsala have been used to compare the results to known climate variations. Various models and equations assess the contribution of peatlands to the global carbon economy and the role that peat accumulation plays in global climate due to global carbon cycling and the concern of increasing levels of greenhouse gases. The importance of peatlands in the global carbon economy is stressed by that it is approximately the same amount of carbon in peatlands as in the atmosphere. Estimations of the total amount of carbon stored in Boreal and Arctic peatlands are in the magnitude of 400-500 Pg. The peat accumulation rate varies by at least a magnitude in peatlands with different conditions in internal and external hydrology, length in growth season, effective precipitation, temperature etc. Accumulation rates have been reported from a variety of temperate and boreal bogs ranging between 0.2-2.0 mm/year and a Boreal and northern Sub-arctic region average of carbon accumulated in the catotelm has been calculated to ca 21 g C/m{sup 2}/year. The proportion of nitrogen in the dry mass is usually in the order of 0.5-5%. The mean accumulation rate of carbon and nitrogen during the last 157 years at Aeltabergsmossen are 7 g C/m{sup 2}/year and 1 g N/m{sup 2}/year, these levels are similar to the ones found in other investigations as well as

  12. Physical parameters and accumulation rates in peat in relation to the climate during the last 150 years

    International Nuclear Information System (INIS)

    Borgmark, Anders

    2006-12-01

    The safety assessment made by SKB (SR 97) states that radionuclides can be accumulated in higher amounts in peatlands than in other recipients. Therefore is knowledge about the nature and properties of peat very important. Here is the decay of peat and the accumulation rate of the most important elements of peat examined further. Two ombrotrophic peat bogs located in Uppland have been investigated in order to evaluate the influences of climate on the accumulation of carbon and nitrogen. Peat humification, content of carbon and nitrogen has been used for interpretation of peat forming processes. The long temperature and precipitation records from Uppsala have been used to compare the results to known climate variations. Various models and equations assess the contribution of peatlands to the global carbon economy and the role that peat accumulation plays in global climate due to global carbon cycling and the concern of increasing levels of greenhouse gases. The importance of peatlands in the global carbon economy is stressed by that it is approximately the same amount of carbon in peatlands as in the atmosphere. Estimations of the total amount of carbon stored in Boreal and Arctic peatlands are in the magnitude of 400-500 Pg. The peat accumulation rate varies by at least a magnitude in peatlands with different conditions in internal and external hydrology, length in growth season, effective precipitation, temperature etc. Accumulation rates have been reported from a variety of temperate and boreal bogs ranging between 0.2-2.0 mm/year and a Boreal and northern Sub-arctic region average of carbon accumulated in the catotelm has been calculated to ca 21 g C/m 2 /year. The proportion of nitrogen in the dry mass is usually in the order of 0.5-5%. The mean accumulation rate of carbon and nitrogen during the last 157 years at Aeltabergsmossen are 7 g C/m 2 /year and 1 g N/m 2 /year, these levels are similar to the ones found in other investigations as well as more

  13. Optimization of beryllium for fusion blanket applications

    International Nuclear Information System (INIS)

    Billone, M.C.

    1993-01-01

    The primary function of beryllium in a fusion reactor blanket is neutron multiplication to enhance tritium breeding. However, because heat, tritium and helium will be generated in and/or transported through beryllium and because the beryllium is in contact with other blanket materials, the thermal, mechanical, tritium/helium and compatibility properties of beryllium are important in blanket design. In particular, tritium retention during normal operation and release during overheating events are safety concerns. Accommodating beryllium thermal expansion and helium-induced swelling are important issues in ensuring adequate lifetime of the structural components adjacent to the beryllium. Likewise, chemical/metallurgical interactions between beryllium and structural components need to be considered in lifetime analysis. Under accident conditions the chemical interaction between beryllium and coolant and breeding materials may also become important. The performance of beryllium in fusion blanket applications depends on fabrication variables and operational parameters. First the properties database is reviewed to determine the state of knowledge of beryllium performance as a function of these variables. Several design calculations are then performed to indicate ranges of fabrication and operation variables that lead to optimum beryllium performance. Finally, areas for database expansion and improvement are highlighted based on the properties survey and the design sensitivity studies

  14. Thermal safety analysis for pebble bed blanket fusion-fission hybrid reactor

    International Nuclear Information System (INIS)

    Wei Renjie

    1998-01-01

    Pebble bed blanket hybrid reactor may have more advantages than slab element blanket hybrid reactor in nuclear fuel production and nuclear safety. The thermo-hydraulic calculations of the blanket in the Tokamak helium cooling pebble bed blanket fusion-fission hybrid reactor developed in China are carried out using the Code THERMIX and auxiliary code. In the calculations different fuel pebble material and steady state, depressurization and total loss of flow accident conditions are included. The results demonstrate that the conceptual design of the Tokamak helium cooling pebble bed blanket fusion-fission hybrid reactor with dump tank is feasible and safe enough only if the suitable fuel pebble material is selected and the suitable control system and protection system are established. Some recommendations for due conceptual design are also presented

  15. Design requirement on KALIMER blanket fuel assembly duct

    International Nuclear Information System (INIS)

    Hwang, Woan; Kang, H. Y.; Nam, C.; Kim, J. O.

    1998-03-01

    This document describes design requirements which are needed for designing the blanket fuel assembly duct of the KALIMER as design guidance. The blanket fuel assembly duct of the KALIMER consists of fuel rods, mounting rail, nosepiece, duct with pad, handling socket with pad. Blanket fuel rod consists of top end plug, bottom end plug with solid ferritic-martensitic steel rod and key way blanket fuel slug, cladding, and wire wrap. In the assembly, the rods are in a triangular pitch array, and the rod bundle is attached to the nosepiece with mounting rails. The bottom end of the assembly duct is formed by a long nosepiece which provides the lower restraint function and the paths for coolant inlet. This report contains functional requirements, performance and operational requirements, interfacing systems requirements, core restraint and interface requirements, design limits and strength requirements, system configuration and essential feature requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. (author). 20 refs., 4 figs

  16. Stress analysis of blanket vessel for JAERI experimental fusion reactor

    International Nuclear Information System (INIS)

    Sako, K.; Minato, A.

    1979-01-01

    A blanket structure of JAERI Experimental Fusion Reactor (JXFR) consists of about 2,300 blanket cells with round cornered rectangular cross sections (twelve slightly different shapes) and is placed in a vacuum vessel. Each blanket vessel is a double-walled thin-shell structure made of Type 316 stainless steel with a spherical domed surface at the plasma side. Ribs for coolant channel are provided between inner and outer walls. The blanket cell contains Li 2 O pebbles and blocks for tritium breeding and stainless steel blocks for neutron reflection. A coolant is helium gas at 10 kgf/cm 2 (0.98 MPa) and its inlet and outlet temperatures are 300 0 C and 500 0 C. The maxima of heat flux and nuclear heating rate at the first wall are 12 W/cm 2 and 2 W/cc. A design philosophy of the blanket structure is based on high tritium breeding ratio and more effective shielding performance. The thin-shell vessel with a rectangular cross section satisfies the design philosophy. We have designed the blanket structure so that the adjacent vessels are mutually supporting in order to decrease the large deformation and stress due to internal pressure in case of the thin-shell vessel. (orig.)

  17. Greenhouse gas balances of Frisian peat pastures. Long term effects of land use options.

    NARCIS (Netherlands)

    Keijzer, Elisabeth

    2010-01-01

    SUMMARY Peat pastures in the Dutch province of Friesland emit high amounts of greenhouse gases (CO2, N2O, and CH4). These high emissions are the results of deep drainage of the peat for agricultural purposes and consequently oxidation of the peat. Other

  18. Bacterial degradation of styrene in waste gases using a peat filter

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, M.; Reittu, A. [Kuopio Univ. (Finland). Dept. of Environmental Sciences; Wright, A. von; Suihko, M.L. [VTT Biotechnology and Food Research (Finland); Martikainen, P.J. [Kuopio Univ. (Finland). Dept. of Environmental Sciences]|[National Public Health Inst., Lab. of Environmental Microbiology, Kuopio (Finland)

    1997-12-31

    A biofiltration process was developed for styrene-containing off-gases using peat as filter material. The average styrene reduction ratio after 190 days of operation was 70% (max. 98%) and the mean styrene elimination capacity was 12 g m{sup -3} h{sup -1} (max. 30 g m{sup -3} h{sup -1}). Efficient styrene degradation required addition of nutrients to the peat, adjustment of the pH to a neutral level and efficient control of the humidity. Maintenance of the water balance was easier in a down-flow than in an up-flow process, the former consequently resulting in much better filtration efficiency. The optimum operation temperature was around 23 C, but the styrene removal was still satisfactory at 12 C. Seven different bacterial isolates belonging to the genera Tsukamurella, Pseudomonas, Sphingomonas, Xanthomonas and an unidentified genus in the {gamma} group of the Proteobacteria isolated from the microflora of active peat filter material were capable of styrene degradation. The isolates differed in their capacity to decompose styrene to carbon dioxide and assimilate it to biomass. No toxic intermediate degradation products of styrene were detected in the filter outlet gas or in growing cultures of isolated bacteria. The use of these isolates in industrial biofilters is beneficial at low styrene concentrations and is safe from both the environmental and public health points of view. (orig.)

  19. Bacterial degradation of styrene in waste gases using a peat filter.

    Science.gov (United States)

    Arnold, M; Reittu, A; von Wright, A; Martikainen, P J; Suihko, M L

    1997-12-01

    A biofiltration process was developed for styrene-containing off-gases using peat as filter material. The average styrene reduction ratio after 190 days of operation was 70% (max. 98%) and the mean styrene elimination capacity was 12 g m-3 h-1 (max. 30 g m-3 h-1). Efficient styrene degradation required addition of nutrients to the peat, adjustment of the pH to a neutral level and efficient control of the humidity. Maintenance of the water balance was easier in a down-flow than in an up-flow process, the former consequently resulting in much better filtration efficiency. The optimum operation temperature was around 23 degrees C, but the styrene removal was still satisfactory at 12 degrees C. Seven different bacterial isolates belonging to the genera Tsukamurella, Pseudomonas, Sphingomonas, Xanthomonas and an unidentified genus in the gamma group of the Proteobacteria isolated from the microflora of active peat filter material were capable of styrene degradation. The isolates differed in their capacity to decompose styrene to carbon dioxide and assimilate it to biomass. No toxic intermediate degradation products of styrene were detected in the filter outlet gas or in growing cultures of isolated bacteria. The use of these isolates in industrial biofilters is beneficial at low styrene concentrations and is safe from both the environmental and public health points of view.

  20. Status of blanket design for RTO/RC ITER

    International Nuclear Information System (INIS)

    Yamada, M.; Ioki, K.; Cardella, A.; Elio, F.; Miki, N.

    2000-01-01

    Design has progressed on the FW/blanket for the RTO/RC (reduced technical objective/ reduced cost) ITER. The basic functions and structures are the same as for the 1998 ITER design. However, design and fabrication methods of the FW/blanket have been improved to achieve ∝ 50% reduction of the construction cost compared to that for the 1998 ITER design. Detailed blanket module designs with flat separable FW panels have been developed to reduce the fabrication cost and the future radioactive waste. Most of the R and D performed so far during the EDA (engineering design activity) is still applicable. Further cost reduction methods are also being investigated and additional R and D is being performed. (orig.)

  1. Fusion blankets for catalyzed D--D and D--He3 reactors

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.

    1977-01-01

    Blanket designs are presented for catalyzed D-D (Cat-D) and D-He 3 fusion reactors. Because of relatively low neutron wall loads and the flexibility due to non-tritium breeding, blankets potentially should operate for reactor life-times of approximately 30 years. Unscheduled replacement of failed blanket modules should be relatively rapid, due to very low residual activity, by operators working either through access ports in the shield (option 1) or directly in the plasma chamber (option 2). Cat-D blanket designs are presented for high (approximately 30%) and low (approximately 12%) β noncircular Tokamak reactors. The blankets are thick graphite screens, operating at high temperature to anneal radiation damage; the deposited neutron and gamma energy is thermally radiated along internal cavities and conducted to a bank of internal SiC coolant tubes (approximately 4 cm. ID) containing high pressure helium. In the D-He 3 Tokamak reactor design, the blanket consists of multiple layers (e.g., three) of thin (approximately 10 cm.) high strength aluminum (e.g., SAP), modular plates, cooled by organic terphynyl coolant

  2. Fusion blankets for catalyzed D--D and D--3He reactors

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.

    1977-01-01

    Blanket designs are presented for catalyzed D-D (Cat-D) and D-He 3 fusion reactors. Because of relatively low neutron wall loads and the flexibility due to non-tritium breeding, blankets potentially should operate for reactor life-times of approximately 30 years. Unscheduled replacement of failed blanket modules should be relatively rapid, due to very low residual activity, by operators working either through access ports in the shield (option 1) or directly in the plasma chamber (option 2). Cat-D blanket designs are presented for high (approximately 30%) and low (approximately 12%) β non-circular Tokamak reactors. The blankets are thick graphite screens, operating at high temperature to anneal radiation damage; the deposited neutron and gamma energy is thermally radiated along internal cavities and conducted to a bank of internal SiC coolant tubes (approximately 4 cm. ID) containing high pressure helium. In the D-He 3 Tokamak reactor design, the blanket consists of multiple layers (e.g., three) of thin (approximately 10 cm.) high strength aluminum (e.g., SAP), modular plates, cooled by organic terphenyl coolant

  3. The occurrence and development of peat mounds on King George Island (Maritime Antarctic

    Directory of Open Access Journals (Sweden)

    Jerzy Fabiszewski

    2014-01-01

    Full Text Available On King George Island, South Shetlands Islands, a type of peat formation has been discovered which has not previously been reported from the Antarctic. These formations are in shape of mounds up to 7x 15 m in area, with a peat layer of about I m thick. About twenty five cm below the surface there is a layer of permanently frozen peat. The mounds are covered by living mosses (Polytrichum alpinum and Drepanocladus uncinatus, Antarctic hair grass (Deschampsia antarctica and lichens. Erosion fissures occurring on the surface are evidence of contemporary drying and cessation of the mound's growth. The initial phase of the development of the mounds began with a community dominated by Calliergidium austro-stramineum and Deschampsia antarctica, and their further development has been due to peat accumulation formed almost entirely by Calliergidium. The location of the mounds is near a penguin rookery, which clearly conditioned the minerotrophic character of these formations, as compared with the "moss peat banks" formed by Chorisodontium aciphyllum and Polytrichum al-pestre. Moreover, the peat mounds differ from the latter in several ways, e.g. rate of growth and floristic composition. Radiocarbon dating of peat from the base of one mound gave an age of 4090±60 years B.P. This suggests that the age of the tundra on King George Island is about 5000-4000 years.

  4. Gasification of peat and biomass in suspension flow; Turpeen ja biomassan suspensiokaasutus

    Energy Technology Data Exchange (ETDEWEB)

    Raiko, R.; Haukka, P. [Tampere Univ. of Technology (Finland). Thermal Engineering

    1995-11-01

    This is the second phase of a project that started with examination of a gasification process for fuels containing high amounts of volatiles such as biomass. In the earlier phase of the project the gasification process was studied with the aid of computer models. Gas production with this gasification method is based mainly on rapid pyrolysis in dilute suspension flow enabling high solid to gas conversion. The two-stage approach eliminates char gasification as a limiting process step, and consequently, allows product temperature to be controlled by the kinetics of volatile reactions. A greater amount of enthalpy is made available for rapid pyrolysis through the total combustion of the residual char than is possible by partial oxidation. The main goal in the second year (1994) was to get experimental information on peat reactivity, main pyrolysis products and formation of nitrogen compounds in the early stages of peat pyrolysis in dilute pressurized flow conditions. These experiments were conducted using pressurized entrained flow reactor at VTT Energy (Jyvaeskylae). Preliminary experiments gave the result that pressure increase accelerates pyrolysis of peat at first (residence time < 100 ms), but this difference disappears gradually. The total amount of volatile matter does not seem to depend on pressure level. (author)

  5. The contribution to the greenhouse effect from the use of peat and coal for energy

    International Nuclear Information System (INIS)

    Zetterberg, L.; Klemedtsson, L.

    1996-06-01

    Emissions and uptake of greenhouse gases have been estimated for the production and combustion of peat in four Swedish regions. Net emissions have been defined as the sum of emissions and uptake from mining, loading, transportation, combustion and forestation of the peat land minus emissions from the virgin peat land. Cropping of the forested peat land is not considered. Net CO 2 -emissions from the production and combustion of peat is estimated to be 87 g/MJ in the regions Bergslagen and Smaaland, 99 g/MJ in Haerjedalen and 95 g/MJ in Vaesterbotten kustland. Net N 2 -emissions are estimated to be 66 mg/MJ for all regions. Due to the natural methane emissions from a virgin peat bog, the production and combustion of peat reduces net CH 4 -emissions by 0.9 g CH 4 /MJ peat. A hypothetical case has been studied where all the drained peat areas are forested (instead of about half of the area as it is today). According to this scenario the net CO 2 -emissions are reduced from 87 to 57 g CO 2 /MJ peat for Bergslagen. As a comparison, CO 2 -emissions from the combustion of coal are ca 92 g CO 2 /MJ. Based on the emissions inventory the contribution to the greenhouse effect has been calculated in terms of the contribution to atmospheric radiative forcing. In conclusion, the contribution to the greenhouse effect from the use of peat for energy from Southern Sweden (Smaaland and Bergslagen) is ca 20% lower than the contribution from coal, counted as an average over 100 years after the mining starts. Corresponding figures for Northern Sweden (Haerjedalen and Vaesterbotten kustland) is ca 15% lower than coal. 21 refs, 12 figs, 7 tabs

  6. TECHNOLOGY AND EFFICIENCY OF PEAT ASH USAGE IN CEMENT CONCRETE

    Directory of Open Access Journals (Sweden)

    G. D. Liakhevich

    2015-01-01

    Full Text Available One of the main ways to improve physical and mechanical properties of cement concrete is an introduction of ash obtained due to burning of fossil fuels into concrete mix. The concrete mixes with ash are characterized by high cohesion, less water gain and disintegration. At the same time the concrete has high strength, density, water resistance, resistance to sulfate corrosion. The aim of this paper is to explore the possibility to use peat ash and slag of peat enterprises of the Republic of Belarus in the concrete for improvement of its physical and mechanical properties and characteristics of peat ash, slag, micro-silica, cement, superplasticizing agent. Compositions and technology for preparation of concrete mixes have been developed and concrete samples have been have been fabricated and tested in the paper. It has been shown that the concrete containing ash, slag obtained due to burning of peat in the industrial installations of the Usiazhsky and Lidsky Peat Briquette Plants and also MK-85-grade micro-silica NSPKSAUsF-1-grade superplasticizing agent have concrete tensile strength within 78–134 MPa under axial compression and 53 MPa – for the control composition. This index is 1.5–2.5 times more than for the sample containing no additives.The usage of peat ash, slag together with MK-85-grade micro-silica and NSPKSAUsF-1-grade superplasticizing agent for fabrication of concrete and reinforced bridge and tunnel structures will provide the following advantages: reduction of cross-sectional area of structures while maintaining their bearing capacity due to higher value of tensile strength in case of axial compression; higher density, waterand gas tightness due to low water cement ratio; high resistance to aggressive environment due to lower content of capillary pores that ensures bridge structure longevity; achievement of environmental and social impacts.

  7. Status report. KfK contribution to the development of DEMO-relevant test blankets for NET/ITER. Pt. 1: Self-cooled liquid metal breeder blanket. Vol. 2. Detailed version

    International Nuclear Information System (INIS)

    John, H.; Malang, S.; Sebening, H.

    1991-12-01

    A self-cooled liquid metal breeder blanket for a fusion DEMO-reactor and the status of the development programme is described as a part of the European development programme of DEMO relevant test blankets for NET/ITER. Volume 1 (KfK 4907) contains a summary. Volume 2 (KfK 4908) a more detailed version of the report. Both volumes contain sections on previous studies on self-cooled liquid metal breeder blankets, the reference blanket design for a DEMO-reactor, a typical test blanket design including the ancillary loop system and the building requirements for NET/ITER together with the present status of the associated RandD-programme in the fields of neutronics, magnetohydrodynamics, tritium removal and recovery, liquid metal compatibility and purification, ancillary loop system, safety and reliability. An outlook is given regarding the required RandD-programme for the self-cooled liquid metal breeder blanket prior to tests in NET/ITER and the relevant test programme to be performed in NET/ITER. (orig.) [de

  8. Peat exploitation - Environment. Effects and measures

    International Nuclear Information System (INIS)

    Stenbeck, G.

    1996-01-01

    This report gives a detailed description of the influence of peat exploitation on the land-, water- and atmospheric environments. Proposals for mitigatory measures to minimize damage to the environment are also given

  9. A Single-Granule-Level Approach Reveals Ecological Heterogeneity in an Upflow Anaerobic Sludge Blanket Reactor.

    Directory of Open Access Journals (Sweden)

    Kyohei Kuroda

    Full Text Available Upflow anaerobic sludge blanket (UASB reactor has served as an effective process to treat industrial wastewater such as purified terephthalic acid (PTA wastewater. For optimal UASB performance, balanced ecological interactions between syntrophs, methanogens, and fermenters are critical. However, much of the interactions remain unclear because UASB have been studied at a "macro"-level perspective of the reactor ecosystem. In reality, such reactors are composed of a suite of granules, each forming individual micro-ecosystems treating wastewater. Thus, typical approaches may be oversimplifying the complexity of the microbial ecology and granular development. To identify critical microbial interactions at both macro- and micro- level ecosystem ecology, we perform community and network analyses on 300 PTA-degrading granules from a lab-scale UASB reactor and two full-scale reactors. Based on MiSeq-based 16S rRNA gene sequencing of individual granules, different granule-types co-exist in both full-scale reactors regardless of granule size and reactor sampling depth, suggesting that distinct microbial interactions occur in different granules throughout the reactor. In addition, we identify novel networks of syntrophic metabolic interactions in different granules, perhaps caused by distinct thermodynamic conditions. Moreover, unseen methanogenic relationships (e.g. "Candidatus Aminicenantes" and Methanosaeta are observed in UASB reactors. In total, we discover unexpected microbial interactions in granular micro-ecosystems supporting UASB ecology and treatment through a unique single-granule level approach.

  10. A Single-Granule-Level Approach Reveals Ecological Heterogeneity in an Upflow Anaerobic Sludge Blanket Reactor

    Science.gov (United States)

    Mei, Ran; Narihiro, Takashi; Bocher, Benjamin T. W.; Yamaguchi, Takashi; Liu, Wen-Tso

    2016-01-01

    Upflow anaerobic sludge blanket (UASB) reactor has served as an effective process to treat industrial wastewater such as purified terephthalic acid (PTA) wastewater. For optimal UASB performance, balanced ecological interactions between syntrophs, methanogens, and fermenters are critical. However, much of the interactions remain unclear because UASB have been studied at a “macro”-level perspective of the reactor ecosystem. In reality, such reactors are composed of a suite of granules, each forming individual micro-ecosystems treating wastewater. Thus, typical approaches may be oversimplifying the complexity of the microbial ecology and granular development. To identify critical microbial interactions at both macro- and micro- level ecosystem ecology, we perform community and network analyses on 300 PTA–degrading granules from a lab-scale UASB reactor and two full-scale reactors. Based on MiSeq-based 16S rRNA gene sequencing of individual granules, different granule-types co-exist in both full-scale reactors regardless of granule size and reactor sampling depth, suggesting that distinct microbial interactions occur in different granules throughout the reactor. In addition, we identify novel networks of syntrophic metabolic interactions in different granules, perhaps caused by distinct thermodynamic conditions. Moreover, unseen methanogenic relationships (e.g. “Candidatus Aminicenantes” and Methanosaeta) are observed in UASB reactors. In total, we discover unexpected microbial interactions in granular micro-ecosystems supporting UASB ecology and treatment through a unique single-granule level approach. PMID:27936088

  11. Preliminary Analysis for K-DEMO Water Cooled Breeding Blanket Using MARS-KS

    International Nuclear Information System (INIS)

    Lee, Jeong-Hun; Kim, Geon-Woo; Park, Goon-Cherl; Cho, Hyoung-Kyu; Im, Kihak

    2014-01-01

    In the present study, thermal-hydraulic analyses for the blanket concept are being conducted using the Multidimensional Analysis of Reactor Safety (MARSKS) code, which has been used for the safety analysis of a pressurized water reactor. The purposes of the analyses are to verify the applicability of the code for the proposed blanket system, to investigate the departure of nucleate boiling (DNB) occurrence during the normal and transient conditions, and to extend the capability of MARS-KS to the entire blanket system which includes a few hundreds of single blanket modules. In this paper, the thermal analysis results of the proposed blanket design using the MARS-KS code are presented for the normal operation and an accident condition of a reduced coolant flow rate. Afterwards, the plan for the whole blanket system analysis using MARSKS is introduced and the result of the first trial for the multiple blanket module analysis is summarized. In the present study, thermal-hydraulic analyses for the blanket concept were conducted using the MARS-KS code for a single blanket module. By comparing the MARS calculation results with the CFD analysis results, it was found that MARS-KS can be applied for the blanket thermal analysis with less number of computational meshes. Moreover, due to its capability on the two-phase flow analysis, it can be used for the transient or accident simulation where a phase change may be resulted in. In the future, the MARS-KS code will be applied for the anticipated transient and design based accident analyses. The investigation of the DNB occurrence during the normal and transient conditions will be of special interest of the analysis using it. After that, a methodology to simulate the entire blanket system was proposed by using the DLL version of MARS-KS. A supervisor program, which controls the multiple DLL files, was developed for the common header modelling. The program explicitly determines the flow rates of each module which can equalize

  12. Calculations of tritium breeding ratio and inventory distributions of FEB blanket

    International Nuclear Information System (INIS)

    Deng Baiquan

    2001-01-01

    Based on the design features of FEB reactor blanket, the tritium breeding ratio and tritium concentrations in liquid lithium of each breeding zone have been calculated after 10 days full power operation for outboard blanket and one day operation for inboard blanket. The comparisons with the results calculated by Monte-Carlo code MORSE-CGT are made. Meanwhile the inventory in beryllium multiplier after one-year full power operation has also been estimated. An important conclusion has been drew the thermal hydraulic design should be careful to guarantee the blanket temperature should not rise as high as 680 degree C

  13. Applications of scanning electron microscopy to the study of mineral matter in peat

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, R. Jr.; Andrejko, M.J.; Bardin, S.W.

    1983-01-01

    Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) have been used for in situ analysis of minerals in peats by combining methods for producing oriented microtome sections of peat with methods for critical point drying. The combined technique allows SEM analysis of the inorganic components and their associated botanical constituents, along with petrographic identification of the botanical constituents. In peat deposits with abundant fluvial- or marine-derived minerals, one may use the above technique and/or medium- or low-temperature ashing followed by x-ray diffraction to readily identify the various mineral components. However, in some freshwater environments the scarcity of non-silica minerals makes the above techniques impractical. By separating the inorganic residues from the peat, one can isolate the non-silica mineral matter in the SEM for analysis by EDS. Furthermore, such separation allows SEM analysis of features and textures of both silica and non-silica mineral particles that might otherwise be unidentifiable. Results indicate the occurrence of detritial minerals in both Okefenokee and Snuggedy Swamp peats, the presence of authigenic or diagenetic minerals growing within peats, and dissolution features on freshwater sponge spicules that may account for the absence of spicules in Tertiary lignites.

  14. A coupled systems code-CFD MHD solver for fusion blanket design

    Energy Technology Data Exchange (ETDEWEB)

    Wolfendale, Michael J., E-mail: m.wolfendale11@imperial.ac.uk; Bluck, Michael J.

    2015-10-15

    Highlights: • A coupled systems code-CFD MHD solver for fusion blanket applications is proposed. • Development of a thermal hydraulic systems code with MHD capabilities is detailed. • A code coupling methodology based on the use of TCP socket communications is detailed. • Validation cases are briefly discussed for the systems code and coupled solver. - Abstract: The network of flow channels in a fusion blanket can be modelled using a 1D thermal hydraulic systems code. For more complex components such as junctions and manifolds, the simplifications employed in such codes can become invalid, requiring more detailed analyses. For magnetic confinement reactor blanket designs using a conducting fluid as coolant/breeder, the difficulties in flow modelling are particularly severe due to MHD effects. Blanket analysis is an ideal candidate for the application of a code coupling methodology, with a thermal hydraulic systems code modelling portions of the blanket amenable to 1D analysis, and CFD providing detail where necessary. A systems code, MHD-SYS, has been developed and validated against existing analyses. The code shows good agreement in the prediction of MHD pressure loss and the temperature profile in the fluid and wall regions of the blanket breeding zone. MHD-SYS has been coupled to an MHD solver developed in OpenFOAM and the coupled solver validated for test geometries in preparation for modelling blanket systems.

  15. DEMO relevance of the test blanket modules in ITER-Application to the European test blanket modules

    International Nuclear Information System (INIS)

    Magnani, E.; Gabriel, F.; Boccaccini, L.V.; Li-Puma, A.

    2010-01-01

    Test blanket module (TBM) testing programme in ITER as a support to DEMO design is a very important step on the road map to commercial fusion reactors although it is an ambitious task. Finding as much as possible DEMO relevant tests in view of the future DEMO blanket design is therefore a major goal since ITER and DEMO environment and loading conditions are different. To clarify and quantify the meaning of the DEMO relevance, criteria using a structural, functional and behavioural representation of the breeding blanket acting as a system are investigated. Then, a three-step strategy is proposed to carry out TBM DEMO relevant tests associated with a TBM design modification strategy. Key parameters should intensively be used as target for TBM characterization and numerical code validation. When assessing the relevance, on the other hand, not only the actual difference between DEMO and ITER values should be considered, but also whether the analyzed phenomena have a threshold and a range of applicability, as numerical simulations are usually permitted within these limits. The proposed methodology is at the end applied to the design of the HCLL TBM breeding unit configuration.

  16. Mobility of trace metals in pore waters of two Central European peat bogs

    International Nuclear Information System (INIS)

    Novak, Martin; Pacherova, Petra

    2008-01-01

    Vertical peat profiles can only be used as archives of past changes in pollution levels if atmogenic elements are immobile after their burial. For mobile elements, similar pore-water concentrations can be expected at different peat depths. Concentrations of Pb, Cu, Zn, Cr, Mn, Fe, Co and Cd were determined in surface bog water and bog pore water 40 cm below surface in two Sphagnum-dominated peat bogs in the Czech Republic. Velke jerabi jezero (VJJ) is an upland bog located in an industrial area, Cervene blato (CB) is a lowland bog located in a rural area. Metal concentrations were monitored seasonally over 3 years (2002-2005) at both sites. Higher concentrations of Pb, Cu, Zn, Cr and Cd and lower concentrations of Mn, Fe and Co were found at the less polluted CB compared to VJJ. No clear-cut seasonality was observed in metal concentrations in bog waters, despite seasonal differences in industrial emission rates of pollutants (more coal burning in winter than in summer). This contrasts with an earlier observation of distinct seasonality in sulfate concentration and isotope composition in these stagnating bog waters. Peat substrate 40 cm below current bog surface represented pre-industrial low-pollution environment, yet pore waters at such depths contained the same metal concentrations as surface waters. The only exception was Pb, whose concentration in water solutes increased with increasing depth. Lack of vertical stratification in pore-water contents of Cu, Zn, Cr, Mn, Fe and Co indicated vertical mobility of these metals

  17. Overview of first wall/blanket/shield technology

    International Nuclear Information System (INIS)

    Nygren, R.E.

    1983-04-01

    This brief overview of first wall, blanket, and shield technology focuses first on changes and trends in important design issues from the 1970's to the 1980's, then on current perceptions of critical issues in first wall, blanket, and shield design and related technology. The emphasis is on base technology rather than either systems engineering or materials development, on the two primary confinement systems, tokamaks and mirrors, and on production of electricity as the primary goal for development

  18. Peat Biomass Smoke Particle Exposure in Rats Decreases ...

    Science.gov (United States)

    Wildland fires, favored by prolonged drought and rising temperatures, generate significant amounts of ambient particulate matter (PM), which has been linked to adverse health outcomes. The eastern North Carolina peat fires of Pocosin Lake in 2008 and Pains Bay in 2011 were some of the more prominent recent wildland fires and were associated with increased cardiovascular hospitalizations. The biological impacts of peat biomass emissions and the specific mechanisms driving these responses are unclear. The purpose of this study was to investigate the cardiopulmonary responses of peat biomass smoke exposure in rats. We hypothesized that PM exposure would dose-dependently alter cardiopulmonary function. Male Sprague-Dawley rats were exposed to 30 µg (Lo PM) or 300 µg (Hi PM) of peat biomass smoke PM extracts suspended in 200 µL of saline, or saline vehicle alone by oropharyngeal aspiration (OA). Immediately following OA rats were placed in a whole-body plethysmograph and ventilatory data were recorded for 12 minutes. One day following OA, rats were anesthetized with isoflurane for ultrasound assessment of cardiovascular function. Hi PM caused decreases in expiratory timing as early as 4-6 minutes after exposure relative to Lo PM (p = 0.02) and Vehicle (p= 0.06), which resolved shortly thereafter. One day after OA, ultrasounds revealed that Hi PM exposure increased end diastolic volume (EDV) by 16% (p = 0.03) over Vehicle and 13% (p = 0.06) over Lo PM. In addition,

  19. Study of the organic material in peat formations in Puerto de Tornos (Santander)

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, M C; Almendrus, G; Dorado, E; Polo, A

    1985-01-01

    Different hydrophysical, agrochemical and biochemical features in a raised peat from Puerto de Tornos (Santander, Northern Spain) have been described. Correlations and affinities among data were studied in seven peat horizons. The studied peat was constituted by the alternance of humic and sapric layers, showing a very high content in extractable humic substances, and a low proportion of exchangeable cations, mainly in deeper layers.

  20. Liquid metal magnetohydrodynamic flows in manifolds of dual coolant lead lithium blankets

    Energy Technology Data Exchange (ETDEWEB)

    Mistrangelo, C., E-mail: chiara.mistrangelo@kit.edu; Bühler, L.

    2014-10-15

    Highlights: • MHD flows in model geometries of DCLL blanket manifolds. • Study of velocity, pressure distributions and flow partitioning in parallel ducts. • Flow partitioning affected by 3D MHD pressure drop and velocity distribution in the expanding zone. • Reduced pressure drop in a continuous expansion compared to a sudden expansion. - Abstract: An attractive blanket concept for a fusion reactor is the dual coolant lead lithium (DCLL) blanket where reduced activation steel is used as structural material and a lead lithium alloy serves both to produce tritium and to remove the heat in the breeder zone. Helium is employed to cool the first wall and the blanket structure. Some critical issues for the feasibility of this blanket concept are related to complex induced electric currents and 3D magnetohydrodynamic (MHD) phenomena that occur in distributing and collecting liquid metal manifolds. They can result in large pressure drop and undesirable flow imbalance in parallel poloidal ducts forming blanket modules. In the present paper liquid metal MHD flows are studied for different design options of a DCLL blanket manifold with the aim of identifying possible sources of flow imbalance and to predict velocity and pressure distributions.

  1. Studies on steps affecting tritium residence time in solid blanket

    International Nuclear Information System (INIS)

    Tanaka, Satoru

    1987-01-01

    For the self sustaining of CTR fuel cycle, the effective tritium recovery from blankets is essential. This means that not only tritium breeding ratio must be larger than 1.0, but also high recovering speed is required for the short residence time of tritium in blankets. Short residence time means that the tritium inventory in blankets is small. In this paper, the tritium residence time and tritium inventory in a solid blanket are modeled by considering the steps constituting tritium release. Some of these tritium migration processes were experimentally evaluated. The tritium migration steps in a solid blanket using sintered breeding materials consist of diffusion in grains, desorption at grain edges, diffusion and permeation through grain boundaries, desorption at particle edges, diffusion and percolation through interconnected pores to purging stream, and convective mass transfer to stream. Corresponding to these steps, diffusive, soluble, adsorbed and trapped tritium inventories and the tritium in gas phase are conceivable. The code named TTT was made for calculating these tritium inventories and the residence time of tritium. An example of the results of calculation is shown. The blanket is REPUTER-1, which is the conceptual design of a commercial reversed field pinch fusion reactor studied at the University of Tokyo. The experimental studies on the migration steps of tritium are reported. (Kako, I.)

  2. Peat hybrid sorbents for treatment of wastewaters and remediation of polluted environment

    Science.gov (United States)

    Klavins, Maris; Burlakovs, Juris; Robalds, Artis; Ansone-Bertina, Linda

    2015-04-01

    For remediation of soils and purification of polluted waters, wastewaters, sorbents might be considered as an prospective group of materials and amongst them peat have a special role due to low cost, biodegradability, high number of functional groups, well developed surface area and combination of hydrophilic/hydrophobic structural elements. Peat as sorbent have good application potential for removal of trace metals, and we have demonstrated peat sorption capacities, sorption kinetics, thermodynamics in respect to metals with different valencies - Tl(I), Cu(II), Cr(III). However peat sorption capacity in respect to nonmetallic (anionic species) elements is low. Also peat mechanical properties do not support application in large scale column processes. To expand peat application possibilities the approach of biomass based hybrid sorbents has been elaborated. The concept "hybrid sorbent" in our understanding means natural, biomass based sorbent modified, covered with another sorbent material, thus combining two types of sorbent properties, sorbent functionalities, surface properties etc. As the "covering layer" both inorganic substances, mineral phases (iron oxohydroxides, oxyapatite) both organic polymers (using graft polymerization) were used. The obtained sorbents were characterised by their spectral properties, surface area, elemental composition. The obtained hybrid sorbents were tested for sorption of compounds in anionic speciation forms, for example of arsenic, antimony, tellurium and phosphorous compounds in comparison with weakly basic anionites. The highest sorption capacity was observed when peat sorbents modified with iron compounds were used. Sorption of different arsenic speciation forms onto iron-modified peat sorbents was investigated as a function of pH and temperature. It was established that sorption capacity increases with a rise in temperature, and the calculation of sorption process thermodynamic parameters indicates the spontaneity of sorption

  3. Peatlands in Finland accumulate carbon more than the peat production and utilization liberates it

    International Nuclear Information System (INIS)

    Maentymaa, E.

    1997-01-01

    The peatlands in Finland bind more carbon dioxide then it is liberated into the air in peat combustion and production. Because the carbon accumulation into peatlands is higher than that of liberation, the peat deposits increase all the time in spite of peat economy. The emissions of methane, which is tens of times worse greenhouse gas then CO 2 , have decreased by 40 % due to forest drainage. Very small amounts of methane is released into the atmosphere from peat production sites. This is proven by the national SILMU research programme investigating the atmospheric changes

  4. Constructing deposition chronologies for peat deposits using radiocarbon dating

    Directory of Open Access Journals (Sweden)

    N. Piotrowska

    2011-06-01

    Full Text Available Radiocarbon dating is one of the main methods used to establish peat chronologies. This article reviews the basis of the method and its application to dating of peat deposits. Important steps in the radiocarbon dating procedure are described, including selection and extraction of material (and fractions for dating, chemical and physical preparation of media suitable for measurements, measurements of 14C activity or concentration, calculations, calibration of results and age-depth modelling.

  5. Tritium inventory in Li2ZrO3 blanket

    International Nuclear Information System (INIS)

    Nishikawa, M.; Baba, A.

    1998-01-01

    Recently, we have presented the way to estimate the tritium inventory in a solid breeder blanket considering effects of diffusion of tritium in the grain, absorption of water in the bulk of grain, and adsorption of water on the surface of grain, together with two types of isotope exchange reactions. It is reported in our previous paper that the estimated tritium inventory for a LiAlO 2 blanket agrees well with data observed in various in situ experiments when the effective diffusivity of tritium from the EXOTIC-6 experiment is used and that the better agreement is obtained when existence of some water vapor is assumed in the purge gas. The same way as used for a LiAlO 2 blanket is applied to a Li 2 ZrO 3 blanket in this study and the estimated tritium inventory shows a good agreement with data obtained in such in situ experiments as MOZART, EXOTIC-6 and TRINE experiments. (orig.)

  6. Application of vanadium alloys to a fusion reactor blanket

    Energy Technology Data Exchange (ETDEWEB)

    Bethin, J.; Tobin, A. (Grumman Aerospace Corp., Bethpage, NY (USA). Research and Development Center)

    1984-05-01

    Vanadium and vanadium alloys are of interest in fusion reactor blanket applications due to their low induced radioactivity and outstanding elevated temperature mechanical properties during neutron irradiation. The major limitation to the use of vanadium is its sensitivity to oxygen impurities in the blanket environment, leading to oxygen embrittlement. A quantitative analysis was performed of the interaction of gaseous impurities in a helium coolant with vanadium and the V-15Cr-5Ti alloy under conditions expected in a fusion reactor blanket. It was shown that the use of unalloyed V would impose severe restrictions on the helium gas cleanup system due to excessive oxygen buildup and embrittlement of the metal. However, internal oxidation effects and the possibly lower terminal oxygen solubility in the alloy would impose much less severe cleanup constraints. It is suggested that V-15Cr-5Ti is a promising candidate for certain blanket applications and deserves further consideration.

  7. Ground-penetrating radar study of the Cena Bog, Latvia: linkage of reflections with peat moisture content

    Directory of Open Access Journals (Sweden)

    Karušs, J.

    2015-12-01

    Full Text Available Present work illustrates results of the ground-penetrating radar (GPR study of the Cena Bog, Latvia. Six sub-horizontal reflections that most probably correspond to boundaries between sediments with different electromagnetic properties were identified. One of the reflections corresponds to bog peat mineral bottom interface but the rest are linked to boundaries within the peat body. The radar profiles are incorporated with sediment cores and studies of peat moisture and ash content, and degree of decomposition. Most of the electromagnetic wave reflections are related to changes in peat moisture content. The obtained data show that peat moisture content changes of at least 3 % are required to cause GPR signal reflection. However, there exist reflections that do not correlate with peat moisture content. As a result, authors disagree with a dominant opinion that all reflections in bogs are solely due to changes in volumetric peat moisture content.

  8. Updated conceptual design of helium cooling ceramic blanket for HCCB-DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Suhao [University of Science and Technology of China, Hefei, Anhui (China); Southwestern Institute of Physics, Chengdu, Sichuan (China); Cao, Qixiang; Wu, Xinghua; Wang, Xiaoyu; Zhang, Guoshu [Southwestern Institute of Physics, Chengdu, Sichuan (China); Feng, Kaiming, E-mail: fengkm@swip.ac.cn [Southwestern Institute of Physics, Chengdu, Sichuan (China)

    2016-11-15

    Highlights: • An updated design of Helium Cooled Ceramic breeder Blanket (HCCB) for HCCB-DEMO is proposed in this paper. • The Breeder Unit is transformed to TBM-like sub-modules, with double “banana” shape tritium breeder. Each sub-module is inserted in space formed by Stiffen Grids (SGs). • The performance analysis is performed based on the R&D development of material, fabrication technology and safety assessment in CN ITER TBM program. • Hot spots will be located at the FW bend side. - Abstract: The basic definition of the HCCB-DEMO plant and preliminary blanket designed by Southwestern Institution of Physics was proposed in 2009. The DEMO fusion power is 2550 MW and electric power is 800 MW. Based on development of R&D in breeding blanket, a conceptual design of helium cooled blanket with ceramic breeder in HCCB-DEMO was presented. The main design features of the HCCB-DEMO blanket were: (1) CLF-1 structure materials, Be multiplier and Li{sub 4}SiO{sub 4} breeder; (2) neutronic wall load is 2.3 MW/m{sup 2} and surface heat flux is 0.43 MW/m{sup 2} (2) TBR ≈ 1.15; (3) geometry of breeding units is ITER TBM-like segmentation; (4)Pressure of helium is 8 MPa and inlet/outlet temperature is 300/500 °C. On the basis of these design, some important analytical results are presented in aspects of (i) neutronic behavior of the blanket; (ii) design of 3D structure and thermal-hydraulic lay-out for breeding blanket module; (iii) structural-mechanical behavior of the blanket under pressurization. All of these assessments proved current stucture fulfill the design requirements.

  9. Processing and waste disposal representative for fusion breeder blanket systems

    International Nuclear Information System (INIS)

    Finn, P.A.; Vogler, S.

    1987-01-01

    This study is an evaluation of the waste handling concepts applicable to fusion breeder systems. Its goal is to determine if breeder blanket waste can be disposed of in shallow land burial, the least restrictive method under US Nuclear Regulatory regulations. The radionuclides expected in the materials used in fusion reactor blankets are described, as are plans for reprocessing and disposal of the components of different breeder blankets. An estimate of the operating costs involved in waste disposal is made

  10. Key achievements in elementary R&D on water-cooled solid breeder blanket for ITER test blanket module in JAERI

    Science.gov (United States)

    Suzuki, S.; Enoeda, M.; Hatano, T.; Hirose, T.; Hayashi, K.; Tanigawa, H.; Ochiai, K.; Nishitani, T.; Tobita, K.; Akiba, M.

    2006-02-01

    This paper presents the significant progress made in the research and development (R&D) of key technologies on the water-cooled solid breeder blanket for the ITER test blanket modules in JAERI. Development of module fabrication technology, bonding technology of armours, measurement of thermo-mechanical properties of pebble beds, neutronics studies on a blanket module mockup and tritium release behaviour from a Li2TiO3 pebble bed under neutron-pulsed operation conditions are summarized. With the improvement of the heat treatment process for blanket module fabrication, a fine-grained microstructure of F82H can be obtained by homogenizing it at 1150 °C followed by normalizing it at 930 °C after the hot isostatic pressing process. Moreover, a promising bonding process for a tungsten armour and an F82H structural material was developed using a solid-state bonding method based on uniaxial hot compression without any artificial compliant layer. As a result of high heat flux tests of F82H first wall mockups, it has been confirmed that a fatigue lifetime correlation, which was developed for the ITER divertor, can be made applicable for the F82H first wall mockup. As for R&D on the breeder material, Li2TiO3, the effect of compression loads on effective thermal conductivity of pebble beds has been clarified for the Li2TiO3 pebble bed. The tritium breeding ratio of a simulated multi-layer blanket structure has successfully been measured using 14 MeV neutrons with an accuracy of 10%. The tritium release rate from the Li2TiO3 pebble has also been successfully measured with pulsed neutron irradiation, which simulates ITER operation.

  11. Liquid fuels from Canadian peat by the Waterloo fast pyrolysis process

    Energy Technology Data Exchange (ETDEWEB)

    Piskorz, J.; Majerski, P.; Scott, D.S. (Univ. of Waterloo, ON (Canada))

    1990-06-01

    Two Quebec peats were pyrolyzed in the Waterloo fast pyrolysis process with the objective of maximizing liquid yields. A young sphagnum peat gave maximum organic liquid yields of 45-47% in an optimum range of 450-550{degree}C and 1 atm pressure. Char yields varied from 35% to 26% and gas yields from 12% to 17% over the range. The character of the liquid product changed significantly over the optimum temperature range, with the ratio of water soluble to water insoluble components decreasing from 2.3 to 0.6 as temperature increased, with an accompanying decrease in oxygen content. Pyrolytic oil yields from an old black peat gave similar results, although with somewhat lower yields of organic liquids. Char yield was somewhat higher (33%) at optimum conditions, but gas yield was nearly identical. Upgrading tests of the peat oil obtained a yield of ca 33% of the liquid feed as a gasoline-like liquid under hydrodeoxygenation conditions. 7 refs., 11 figs., 6 tabs.

  12. Distribution of sulphur and trace elements in peat. A literature survey with some additional sulphur analyses

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen, S; Karhu, M

    1981-01-01

    A survey on the literature and contemporary research was made on peat sulphur and trace element studies. Marked variance between different peatlands and peat types has been noted. The available information is still inadequate for generalizations or statistical analysis mainly due to methodological variations and temporal and spatial variations in results. At the moment, the criteria applied in peatland inventories and evaluations are inadequate with respect to peat quality determinations. To some extent the quality of fuel peat should be determined in a mire inventory prior to peatland utilization. The areas over sulphide clay and some sulphate depositions may considerably increase the peat sulphur content. A proposal has been made to include the sulphur content monitoring in the cases where it exceeds 0.3 per cent. The trace elements may also bring about an increase in peat emissions if the deepest peat layers or polluted layers are burnt. The most important elements in this respect are Al, Fe, Mn, Pb, Zn, V, Ni, Hg, Cu, Cr, as well as As and U. The first ten because of the relatively high concentrations and last two because of pollution or toxocity and ore deposit factors. The peat hydrogen ion concentration has a positive correlation with copper and vanadium. The correlation is positive with the cobalt and nickel contents when the pH is low, and negative at a higher pH. A general peat type correlation shows maximum trace element contents in basal Carex peats with subsoil effects. The peat ash content and the Ti, Pb, V, Cr, Ni, and S contents have positive correlations. (Refs. 290).

  13. Effect of increased utilization of wetland for peat harvesting and forest drainage on employment

    Energy Technology Data Exchange (ETDEWEB)

    Carlen, O; Muller, A

    1984-01-01

    Wetlands cover 15 percent of the area of Sweden. Most of it is peatland and part of it supports forest growth. The prognosis of peat production and ditching for drainage is based upon economical evaluations. A questioning of peat producers has also been performed. Two prognoses have been made for the effect of peat fuel production on the employment. By 1990 about 800 man-years were expected. On the advent of government subsidies to peat fuelled plants, about 1000 more jobs were expected. Unemployment and coal fuelled plants as an alternative are understood by implication. Indirect effects are expected among equipment manufacturers amounting to 50-100 yearly workers. Draining of forests and peat-lands will take 124 man-years as a minimum by 1990 and about 200 more if there will be financial assistance.

  14. Design of self-cooled, liquid-metal blankets for tokamak and tandem mirror reactors

    International Nuclear Information System (INIS)

    Cha, Y.S.; Gohar, Y.; Hassanein, A.M.; Majumdar, S.; Picologlou, B.F.; Smith, D.L.; Szo, D.K.

    1985-01-01

    Results of the self-cooled, liquid-metal blanket design from the Blanket Comparison and Selection Study (BCSS) are summarized. The objectives of the BCSS project are to define a small number (about three) of blanket concepts that should be the focus of the blanket research and development (RandD) program, identify and prioritize the critical issues for the leading blanket concepts, and provide technical input necessary to develop a blanket RandD program plan. Two liquid metals (lithium and lithium-lead (17Li-83Pb)) and three structural materials (primary candidate alloy (PCA), ferritic steel (FS) (HT-9), and vanadium alloy (V-15 Cr-5 Ti)) are included in the evaluations for both tokamaks and tandem mirror reactors (TMRs). TMR is of the tube configuration similar to the Mirror Advanced Reactor Study design. Analyses were performed in the following generic areas for each blanket concept: MHD, thermal hydraulics, stress, neutronics, and tritium recovery. Integral analyses were performed to determine the design window for each blanket design. The Li/Li/V blanket for tokamak and the Li/Li/V, LiPb/LiPb/V, and Li/Li/HT-9 blankets for the TMR are judged to be top-rated concepts. Because of its better thermophysical properties and more uniform nuclear heating profile, liquid lithium is a better coolant than liquid 17Li83Pb. From an engineering point of view, vanadium alloy is a better structural material than either FS or PCA since the former has both a higher allowable structural temperature and a higher allowable coolant/structure interface temperature than the latter. Critical feasibility issues and design constraints for the self-cooled, liquid-metal blanket concepts are identified and discussed

  15. A new soil mechanics approach to quantify and predict land subsidence by peat compression

    NARCIS (Netherlands)

    Koster, K.; Erkens, G.; Zwanenburg, C.

    2016-01-01

    Land subsidence threatens many coastal areas. Quantifying current and predicting future subsidence are essential to sustain the viability of these areas with respect to rising sea levels. Despite its scale and severity, methods to quantify subsidence are scarce. In peat-rich subsidence hot spots,

  16. Bringing back the rare - biogeochemical constraints of peat moss establishment in restored cut-over bogs

    Science.gov (United States)

    Raabe, Peter; Blodau, Christian; Hölzel, Norbert; Kleinebecker, Till; Knorr, Klaus-Holger

    2016-04-01

    In rewetted cut-over bogs in north-western Germany and elsewhere almost no spontaneous recolonization of hummock peat mosses, such as Sphagnum magellanicum, S. papillosum or S. rubellum can be observed. However, to reach goals of climate protection every restoration of formerly mined peatlands should aim to enable the re-establishment of these rare but functionally important plant species. Besides aspects of biodiversity, peatlands dominated by mosses can be expected to emit less methane compared to sites dominated by graminoids. To assess the hydrological and biogeochemical factors constraining the successful establishment of hummock Sphagnum mosses we conducted a field experiment by actively transferring hummock species into six existing restoration sites in the Vechtaer Moor, a large peatland complex with active peat harvesting and parallel restoration efforts. The mosses were transferred as intact sods in triplicate at the beginning of June 2016. Six weeks (mid-July) and 18 weeks later (beginning of October) pore water was sampled in two depths (5 and 20 cm) directly beneath the inoculated Sphagnum sods as well as in untreated control plots and analysed for phosphate, ferrous iron, ammonia, nitrate and total organic carbon (TOC). On the same occasions and additionally in December, the vitality of mosses was estimated. Furthermore, the increment of moss height between July and December was measured by using cranked wires and peat cores were taken for lab analyses of nutrients and major element inventories at the depths of pore water sampling. Preliminary results indicate that vitality of mosses during the period of summer water level draw down was strongly negatively related to plant available phosphate in deeper layers of the residual peat. Furthermore, increment of moss height was strongly negatively related to TOC in the upper pore waters sampled in October. Concentration of ferrous iron in deeper pore waters was in general significantly higher beneath

  17. Import of biofuels and peat

    International Nuclear Information System (INIS)

    Albertsson, N.

    1993-06-01

    In areas neighbouring Sweden, i.e., foremost the Baltic States, it is probable that a large part of the available amounts will be consumed on the domestic market. Studies of the possible use of wood fuel in Estonia, Latvia and Lithuania are being made by the World Bank. Considerable investments will probably be made in the near future to replace existing coal- and oil-fired boiler plants with plants burning wood fuel. Consequently, the opportunities for exports of wood fuel will probably be small. In a global perspective, peat is used only to a limited extent as fuel. In the former Soviet Union alone it is estimated that the amount of peat that is economically feasible to extract is about 166x10 9 tonnes at a moisture content of 40%. Among the most interesting bio products that can be used in energy production from different food processing industries are nut-shells and fruit stones. Some stones, such as those in olives, plums and peaches, are excellent as fuels. The advantage with olive stones, in comparison with chips is that the bulk weight is high and the moisture content is low. Olive stones are thus similar to processed biofuels such as pellets. Due to their high energy content the olive stones can replace coal, which cannot be done by unprocessed fuels without expensive investments in materials handling equipment. Our survey shows that processed forest fuels and crushed olive stones are the products of greatest interest for the Swedish market. It also shows that both chips and peat-based products from the Baltic States are competitive

  18. The thin brown line: The crucial role of peat in protecting permafrost in Arctic Alaska

    Science.gov (United States)

    Gaglioti, B.; Mann, D. H.; Farquharson, L. M.; Baughman, C. A.; Jones, B. M.; Romanovsky, V. E.; Williams, A. P.; Andreu-Hayles, L.

    2017-12-01

    Ongoing warming threatens to thaw Arctic permafrost and release its stored carbon, which could trigger a permafrost-carbon feedback capable of augmenting global warming. The effects of warming air temperatures on permafrost are complicated by the fact that across much of the Arctic and Subarctic a mat of living plants and decaying litter cover the ground and buffer underlying permafrost from air temperatures. For simplicity here, we refer to this organic mat as "peat". Because this peat modifies heat flow between ground and air, the rate and magnitude of permafrost responses to changing climate - and hence the permafrost-carbon feedback - are partly slaved to the peat layer's slower dynamics. To explore this relationship, we used 14C-age offsets within lake sediments in Alaskan watersheds underlain by yedoma deposits to track the changing responses of permafrost thaw to fluctuating climate as peat accumulated over the last 14,000 years. As the peat layer built up, warming events became less effective at thawing permafrost and releasing ancient carbon. Consistent with this age-offset record, the geological record shows that early in post-glacial times when the peat cover was still thin and limited in extent, warm intervals triggered extensive thermokarst that resulted in rapid aggradation of floodplains. Today in contrast, hillslopes and floodplains remain stable despite rapid warming, probably because of the buffering effects of the extensive peat cover. Another natural experiment is provided by tundra fires like the 2007 Anaktuvuk River fire that removed the peat cover from tundra underlain by continuous permafrost and resulted in widespread thermkarsting. Further support for peat's critical role in protecting permafrost comes from the results of modeling how permafrost temperatures under different peat thicknesses respond to warming air temperature. Although post-industrial warming has not yet surpassed the buffering capacity of 14,000 years of peat buildup in

  19. Sources and distribution of trace elements in Estonian peat

    Science.gov (United States)

    Orru, Hans; Orru, Mall

    2006-10-01

    This paper presents the results of the distribution of trace elements in Estonian mires. Sixty four mires, representative of the different landscape units, were analyzed for the content of 16 trace elements (Cr, Mn, Ni, Cu, Zn, and Pb using AAS; Cd by GF-AAS; Hg by the cold vapour method; and V, Co, As, Sr, Mo, Th, and U by XRF) as well as other peat characteristics (peat type, degree of humification, pH and ash content). The results of the research show that concentrations of trace elements in peat are generally low: V 3.8 ± 0.6, Cr 3.1 ± 0.2, Mn 35.1 ± 2.7, Co 0.50 ± 0.05, Ni 3.7 ± 0.2, Cu 4.4 ± 0.3, Zn 10.0 ± 0.7, As 2.4 ± 0.3, Sr 21.9 ± 0.9, Mo 1.2 ± 0.2, Cd 0.12 ± 0.01, Hg 0.05 ± 0.01, Pb 3.3 ± 0.2, Th 0.47 ± 0.05, U 1.3 ± 0.2 μg g - 1 and S 0.25 ± 0.02%. Statistical analyses on these large database showed that Co has the highest positive correlations with many elements and ash content. As, Ni, Mo, ash content and pH are also significantly correlated. The lowest abundance of most trace elements was recorded in mires fed only by precipitation (ombrotrophic), and the highest in mires fed by groundwater and springs (minerotrophic), which are situated in the flood plains of river valleys. Concentrations usually differ between the superficial, middle and bottom peat layers, but the significance decreases depending on the type of mire in the following order: transitional mires - raised bogs - fens. Differences among mire types are highest for the superficial but not significant for the basal peat layers. The use of peat with high concentrations of trace elements in agriculture, horticulture, as fuel, for water purification etc., may pose a risk for humans: via the food chain, through inhalation, drinking water etc.

  20. Applications of the Aqueous Self-Cooled Blanket concept

    International Nuclear Information System (INIS)

    Steiner, D.; Embrechts, M.J.; Varsamis, G.; Wrisley, K.; Deutch, L.; Gierszewski, P.

    1986-01-01

    In this paper a novel water-cooled blanket concept is examined. This concept, designated the Aqueous Self-Cooled Blanket (ASCB), employs water with small amounts of dissolved fertile compounds as both the coolant and the breeding medium. The ASCB concept is reviewed and its application in three different contexts is examined: (1) power reactors; (2) near-term devices such as NET; and (3) fusion-fission hybrids