The Experts below are selected from a list of 21939 Experts worldwide ranked by ideXlab platform
J P Adams - One of the best experts on this subject based on the ideXlab platform.
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national low level Waste management program radionuclide report series volume 15 uranium 238
Other Information: PBD: Sep 1995, 1995Co-Authors: J P AdamsAbstract:This report, Volume 15 of the National Low-Level Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of uranium-238 ({sup 238}U). The purpose of the National Low-Level Waste Management Program Radionuclide Report Series is to provide information to state representatives and developers of Low-Level Radioactive Waste disposal facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the Waste disposal facility environment. This report also includes discussions about Waste types and forms in which {sup 238}U can be found, and {sup 238}U behavior in the environment and in the human body.
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national low level Waste management program radionuclide report series volume 10 nickel 63
Other Information: PBD: Feb 1995, 1995Co-Authors: M L Carboneau, J P AdamsAbstract:This report outlines the basic radiological, chemical, and physical characteristics of nickel-63 ({sup 63}Ni) and examines how these characteristics affect the behavior of {sup 63}Ni in various environmental media, such as soils, groundwater, plants, animals, the atmosphere, and the human body. Discussions also include methods of {sup 63}Ni production, Waste types, and Waste forms that contain {sup 63}Ni. The primary source of {sup 63}Ni in the environment has been Low-Level Radioactive Waste material generated as a result of neutron activation of stable {sup 62}Ni that is present in the structural components of nuclear reactor vessels. {sup 63}Ni enters the environment from the dismantling activities associated with nuclear reactor decommissioning. However, small amounts of {sup 63}Ni have been detected in the environment following the testing of thermonuclear weapons in the South Pacific. Concentrations as high as 2.7 Bq{sup a} per gram of sample (or equivalently 0.0022 parts per billion) were observed on Bikini Atoll (May 1954). {sup 63}Ni was not created as a fission product species (e.g., from {sup 235}U or {sup 239}Pu fissions), but instead was produced as a result of neutron capture in {sup 63}Ni, a common nickel isotope present in the stainless steel components of nuclear weapons (e.g., stainless-304 contains {approximately}9% total Ni or {approximately}0.3% {sup 63}Ni).
Mahmoud M Gouda - One of the best experts on this subject based on the ideXlab platform.
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geological and contaminant transport assessment of a low level Radioactive Waste disposal site
Journal of Geochemical Exploration, 2019Co-Authors: Abdelaal M Abdelkarim, Ahmed A Zaki, Waheed Elwan, Mohamed R Elnaggar, Mahmoud M GoudaAbstract:Abstract The protective function of a Radioactive Waste disposal is provided by natural geological barrier itself. Sand and sandstone samples were taken from Inshas rad-Waste disposal site and were subjected to geochemical-physical examinations. The rock volumes of such samples were composed of 70% quartz and 10% plagioclase beside 17% interstitial matter. The weathering indices indicated moderate weathering of the source materials. Provenance studies suggested the derivation from recycled quartoze sediments. The presented high contents of the interstitial Fe2O3 (hematite/goethite) and Al2O3 (clay/kaolinite) were important agents for preventing pollutants transport via adsorption and the reduced porosity (10–20%) and permeability (0.1–6 md). Flow and transport of Cs+ and Sr2+ ions in groundwater was simulated using fixed bed sand column under the effect of initial ion concentration. Hights of mass transfer zones of Cs+ testing beds and their rates of movement and fractional capacities were found to be higher than those of Sr2+. The maximum adsorption capacities were calculated using Thomas and Yoon-Nelson models. The inlet concentration of both metal ions was directly related to the 50% breakthrough time. The obtained data indicated a high opportunity of Inshas area to meet the requirements posed by the International Atomic Energy Agency for shallow disposal.
I.i. Linge - One of the best experts on this subject based on the ideXlab platform.
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Decommissioning strategy for liquid Low-Level Radioactive Waste surface storage water reservoir.
Journal of environmental radioactivity, 2016Co-Authors: S.s. Utkin, I.i. LingeAbstract:Abstract The Techa Cascade of water reservoirs (TCR) is one of the most environmentally challenging facilities resulted from FSUE “PA “Mayak” operations. Its reservoirs hold over 360 mln m 3 of liquid Radioactive Waste with a total activity of some 5 × 10 15 Bq. A set of actions implemented under a special State program involving the development of a strategic plan aimed at complete elimination of TCR challenges (Strategic Master-Plan for the Techa Cascade of water reservoirs) resulted in considerable reduction of potential hazards associated with this facility. The paper summarizes the key elements of this master-plan: defining TCR final state, feasibility study of the main strategies aimed at its attainment, evaluation of relevant long-term decommissioning strategy, development of computational tools enabling the long-term forecast of TCR behavior depending on various engineering solutions and different weather conditions.
Timothy E Payne - One of the best experts on this subject based on the ideXlab platform.
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identification of sources and processes in a low level Radioactive Waste site adjacent to landfills groundwater hydrogeochemistry and isotopes
Australian Journal of Earth Sciences, 2015Co-Authors: Dioni I Cendon, Catherine E Hughes, Jennifer J Harrison, Stuart Hankin, Mathew P Johansen, Timothy E Payne, Henri K Y Wong, Brett Rowling, M Vine, Kerry L WilsherAbstract:Multiple tracer-element and isotope approaches were applied at a 1960s-era Low-Level Radioactive Waste burial site located in the Lucas Heights area on the southwest urban fringe of Sydney, Australia. The site is situated among other municipal and industrial (solid and liquid) Waste disposal sites causing potential mixing of leachates. Local rainfall contains marine-derived major ion ratios that are modified during infiltration depending on Waste interactions. The local geology favours the retention of contaminants by ion-exchange processes within the clay-rich soils and the shale layer underlying the burial site. Local soils experience periodic infiltration and wetting fronts that can fully saturate the Waste trenches (bathtub effect) while surrounding soils are mostly unsaturated with discontinuous perched lenses. Within the trenches, the degradation of organic matter results in localised methanogenesis, as suggested by enriched δ2H and δ13CDIC values in adjacent subsurface water. Movement of contaminan...
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movement of a tritium plume in shallow groundwater at a legacy low level Radioactive Waste disposal site in eastern australia
Journal of Environmental Radioactivity, 2011Co-Authors: Catherine E Hughes, Dioni I Cendon, Jennifer J Harrison, Stuart Hankin, Mathew P Johansen, Timothy E Payne, M Vine, Richard N Collins, Emmy HoffmannAbstract:Abstract Between 1960 and 1968 Low-Level Radioactive Waste was buried in a series of shallow trenches near the Lucas Heights facility, south of Sydney, Australia. Groundwater monitoring carried out since the mid 1970s indicates that with the exception of tritium, no radioactivity above typical background levels has been detected outside the immediate vicinity of the trenches. The maximum tritium level detected in groundwater was 390 kBq/L and the median value was 5400 Bq/L, decay corrected to the time of disposal. Since 1968, a plume of tritiated water has migrated from the disposal trenches and extends at least 100 m from the source area. Tritium in rainfall is negligible, however leachate from an adjacent landfill represents a significant additional tritium source. Study data indicate variation in concentration levels and plume distribution in response to wet and dry climatic periods and have been used to determine pathways for tritium migration through the subsurface.
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appraisal of a cementitious material for Waste disposal neutron imaging studies of pore structure and sorptivity
Cement and Concrete Research, 2010Co-Authors: P J Mcglinn, Timothy E Payne, Frikkie De Beer, Laurence P Aldridge, M J Radebe, Robert Nshimirimana, Daniel R M Brew, Kylie P OlufsonAbstract:Cementitious materials are conventionally used in conditioning intermediate and low level Radioactive Waste. In this study a candidate cement-based Wasteform has been investigated using neutron imaging to characterise the Wasteform for disposal in a repository for Radioactive materials. Imaging showed both the pore size distribution and the extent of the cracking that had occurred in the samples. The rate of the water penetration measured both by conventional sorptivity measurements and neutron imaging was greater than in pastes made from Ordinary Portland Cement. The ability of the cracks to distribute the water through the sample in a very short time was also evident. The study highlights the significant potential of neutron imaging in the investigation of cementitious materials. The technique has the advantage of visualising and measuring, non-destructively, material distribution within macroscopic samples and is particularly useful in defining movement of water through the cementitious materials.
Emmy Hoffmann - One of the best experts on this subject based on the ideXlab platform.
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movement of a tritium plume in shallow groundwater at a legacy low level Radioactive Waste disposal site in eastern australia
Journal of Environmental Radioactivity, 2011Co-Authors: Catherine E Hughes, Dioni I Cendon, Jennifer J Harrison, Stuart Hankin, Mathew P Johansen, Timothy E Payne, M Vine, Richard N Collins, Emmy HoffmannAbstract:Abstract Between 1960 and 1968 Low-Level Radioactive Waste was buried in a series of shallow trenches near the Lucas Heights facility, south of Sydney, Australia. Groundwater monitoring carried out since the mid 1970s indicates that with the exception of tritium, no radioactivity above typical background levels has been detected outside the immediate vicinity of the trenches. The maximum tritium level detected in groundwater was 390 kBq/L and the median value was 5400 Bq/L, decay corrected to the time of disposal. Since 1968, a plume of tritiated water has migrated from the disposal trenches and extends at least 100 m from the source area. Tritium in rainfall is negligible, however leachate from an adjacent landfill represents a significant additional tritium source. Study data indicate variation in concentration levels and plume distribution in response to wet and dry climatic periods and have been used to determine pathways for tritium migration through the subsurface.
