The Experts below are selected from a list of 295578 Experts worldwide ranked by ideXlab platform
T W Bowyer - One of the best experts on this subject based on the ideXlab platform.
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migration of noble Gas tracers at the site of an underground nuclear explosion at the nevada national security site
Journal of Environmental Radioactivity, 2019Co-Authors: Christine Johnson, T W Bowyer, James C Hayes, C E Aalseth, T R Alexander, V Chipman, S Drellack, J E Fast, Bradley G Fritz, Heather E HuckinsgangAbstract:Abstract As part of an underground Gas migration study, two radioactive noble Gases (37Ar and 127Xe) and two stable tracer Gases (SF6 and PFDMCH) were injected into a historic nuclear explosion test chimney and allowed to migrate naturally. The purpose of this experiment was to provide a bounding case (natural transport) for the flow of radioactive noble Gases following an underground nuclear explosion. To accomplish this, Soil Gas samples were collected from a series of boreholes and a range of depths from the shallow subsurface (3 m) to deeper levels (~160 m) over a period of eleven months. These samples have provided insights into the development and evolution of the subsurface plume and constrained the relative migration rates of the radioactive and stable Gas species in the case when the driving pressure from the cavity is low. Analysis of the samples concluded that the stable tracer SF6 was consistently enriched in the subsurface samples relative to the radiotracer 127Xe, but the ratios of SF6 and 37Ar remained similar throughout the samples.
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measurements of argon 39 at the u20az underground nuclear explosion site
Journal of Environmental Radioactivity, 2017Co-Authors: J Mcintyre, T W Bowyer, C E Aalseth, T R Alexander, V Chipman, S Drellack, H Back, B J Bellgraph, M W Cooper, Michael FoxeAbstract:Pacific Northwest National Laboratory reports on the detection of 39Ar at the location of an underground nuclear explosion on the Nevada Nuclear Security Site. The presence of 39Ar was not anticipated at the outset of the experimental campaign but results from this work demonstrated that it is present, along with 37Ar and 85Kr in the subsurface at the site of an underground nuclear explosion. Our analysis showed that by using state-of-the-art technology optimized for radioargon measurements, it was difficult to distinguish 39Ar from the fission product 85Kr. Proportional counters are currently used for high-sensitivity measurement of 37Ar and 39Ar. Physical and chemical separation processes are used to separate argon from air or Soil Gas, yielding pure argon with contaminant Gases reduced to the parts-per-million level or below. However, even with purification at these levels, the beta decay signature of 85Kr can be mistaken for that of 39Ar, and the presence of either isotope increases the measurement background level for the measurement of 37Ar. Measured values for the 39Ar measured at the site ranged from 36,000 milli- Becquerel/standard-cubic-meter-of-air (mBq/SCM) for shallow bore holes to 997,000 mBq/SCM from the rubble chimney from the underground nuclear explosion.
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consideration of impact of atmospheric intrusion in subsurface sampling for investigation of suspected underground nuclear explosions
Journal of Radioanalytical and Nuclear Chemistry, 2016Co-Authors: Justin D Lowrey, Steven R Biegalski, T W Bowyer, Derek A Haas, James C HayesAbstract:Radioactive noble Gases radioxenon and radioargon constitute the primary smoking gun of an underground nuclear explosion. The aim of subsurface sampling of Soil Gas as part of an on-site inspection (OSI) is to search for evidence of a suspected underground nuclear event. It has been hypothesized that atmospheric Gas can disturb Soil Gas concentrations and therefore potentially add to problems in civilian source discrimination verifying treaty compliance under the comprehensive nuclear-test-ban treaty. This work describes a study of intrusion of atmospheric air into the subsurface and its potential impact on an OSI using results of simulations from the underground transport of environmental xenon (UTEX) model.
S Drellack - One of the best experts on this subject based on the ideXlab platform.
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migration of noble Gas tracers at the site of an underground nuclear explosion at the nevada national security site
Journal of Environmental Radioactivity, 2019Co-Authors: Christine Johnson, T W Bowyer, James C Hayes, C E Aalseth, T R Alexander, V Chipman, S Drellack, J E Fast, Bradley G Fritz, Heather E HuckinsgangAbstract:Abstract As part of an underground Gas migration study, two radioactive noble Gases (37Ar and 127Xe) and two stable tracer Gases (SF6 and PFDMCH) were injected into a historic nuclear explosion test chimney and allowed to migrate naturally. The purpose of this experiment was to provide a bounding case (natural transport) for the flow of radioactive noble Gases following an underground nuclear explosion. To accomplish this, Soil Gas samples were collected from a series of boreholes and a range of depths from the shallow subsurface (3 m) to deeper levels (~160 m) over a period of eleven months. These samples have provided insights into the development and evolution of the subsurface plume and constrained the relative migration rates of the radioactive and stable Gas species in the case when the driving pressure from the cavity is low. Analysis of the samples concluded that the stable tracer SF6 was consistently enriched in the subsurface samples relative to the radiotracer 127Xe, but the ratios of SF6 and 37Ar remained similar throughout the samples.
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measurements of argon 39 at the u20az underground nuclear explosion site
Journal of Environmental Radioactivity, 2017Co-Authors: J Mcintyre, T W Bowyer, C E Aalseth, T R Alexander, V Chipman, S Drellack, H Back, B J Bellgraph, M W Cooper, Michael FoxeAbstract:Pacific Northwest National Laboratory reports on the detection of 39Ar at the location of an underground nuclear explosion on the Nevada Nuclear Security Site. The presence of 39Ar was not anticipated at the outset of the experimental campaign but results from this work demonstrated that it is present, along with 37Ar and 85Kr in the subsurface at the site of an underground nuclear explosion. Our analysis showed that by using state-of-the-art technology optimized for radioargon measurements, it was difficult to distinguish 39Ar from the fission product 85Kr. Proportional counters are currently used for high-sensitivity measurement of 37Ar and 39Ar. Physical and chemical separation processes are used to separate argon from air or Soil Gas, yielding pure argon with contaminant Gases reduced to the parts-per-million level or below. However, even with purification at these levels, the beta decay signature of 85Kr can be mistaken for that of 39Ar, and the presence of either isotope increases the measurement background level for the measurement of 37Ar. Measured values for the 39Ar measured at the site ranged from 36,000 milli- Becquerel/standard-cubic-meter-of-air (mBq/SCM) for shallow bore holes to 997,000 mBq/SCM from the rubble chimney from the underground nuclear explosion.
V Chipman - One of the best experts on this subject based on the ideXlab platform.
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migration of noble Gas tracers at the site of an underground nuclear explosion at the nevada national security site
Journal of Environmental Radioactivity, 2019Co-Authors: Christine Johnson, T W Bowyer, James C Hayes, C E Aalseth, T R Alexander, V Chipman, S Drellack, J E Fast, Bradley G Fritz, Heather E HuckinsgangAbstract:Abstract As part of an underground Gas migration study, two radioactive noble Gases (37Ar and 127Xe) and two stable tracer Gases (SF6 and PFDMCH) were injected into a historic nuclear explosion test chimney and allowed to migrate naturally. The purpose of this experiment was to provide a bounding case (natural transport) for the flow of radioactive noble Gases following an underground nuclear explosion. To accomplish this, Soil Gas samples were collected from a series of boreholes and a range of depths from the shallow subsurface (3 m) to deeper levels (~160 m) over a period of eleven months. These samples have provided insights into the development and evolution of the subsurface plume and constrained the relative migration rates of the radioactive and stable Gas species in the case when the driving pressure from the cavity is low. Analysis of the samples concluded that the stable tracer SF6 was consistently enriched in the subsurface samples relative to the radiotracer 127Xe, but the ratios of SF6 and 37Ar remained similar throughout the samples.
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measurements of argon 39 at the u20az underground nuclear explosion site
Journal of Environmental Radioactivity, 2017Co-Authors: J Mcintyre, T W Bowyer, C E Aalseth, T R Alexander, V Chipman, S Drellack, H Back, B J Bellgraph, M W Cooper, Michael FoxeAbstract:Pacific Northwest National Laboratory reports on the detection of 39Ar at the location of an underground nuclear explosion on the Nevada Nuclear Security Site. The presence of 39Ar was not anticipated at the outset of the experimental campaign but results from this work demonstrated that it is present, along with 37Ar and 85Kr in the subsurface at the site of an underground nuclear explosion. Our analysis showed that by using state-of-the-art technology optimized for radioargon measurements, it was difficult to distinguish 39Ar from the fission product 85Kr. Proportional counters are currently used for high-sensitivity measurement of 37Ar and 39Ar. Physical and chemical separation processes are used to separate argon from air or Soil Gas, yielding pure argon with contaminant Gases reduced to the parts-per-million level or below. However, even with purification at these levels, the beta decay signature of 85Kr can be mistaken for that of 39Ar, and the presence of either isotope increases the measurement background level for the measurement of 37Ar. Measured values for the 39Ar measured at the site ranged from 36,000 milli- Becquerel/standard-cubic-meter-of-air (mBq/SCM) for shallow bore holes to 997,000 mBq/SCM from the rubble chimney from the underground nuclear explosion.
T R Alexander - One of the best experts on this subject based on the ideXlab platform.
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migration of noble Gas tracers at the site of an underground nuclear explosion at the nevada national security site
Journal of Environmental Radioactivity, 2019Co-Authors: Christine Johnson, T W Bowyer, James C Hayes, C E Aalseth, T R Alexander, V Chipman, S Drellack, J E Fast, Bradley G Fritz, Heather E HuckinsgangAbstract:Abstract As part of an underground Gas migration study, two radioactive noble Gases (37Ar and 127Xe) and two stable tracer Gases (SF6 and PFDMCH) were injected into a historic nuclear explosion test chimney and allowed to migrate naturally. The purpose of this experiment was to provide a bounding case (natural transport) for the flow of radioactive noble Gases following an underground nuclear explosion. To accomplish this, Soil Gas samples were collected from a series of boreholes and a range of depths from the shallow subsurface (3 m) to deeper levels (~160 m) over a period of eleven months. These samples have provided insights into the development and evolution of the subsurface plume and constrained the relative migration rates of the radioactive and stable Gas species in the case when the driving pressure from the cavity is low. Analysis of the samples concluded that the stable tracer SF6 was consistently enriched in the subsurface samples relative to the radiotracer 127Xe, but the ratios of SF6 and 37Ar remained similar throughout the samples.
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measurements of argon 39 at the u20az underground nuclear explosion site
Journal of Environmental Radioactivity, 2017Co-Authors: J Mcintyre, T W Bowyer, C E Aalseth, T R Alexander, V Chipman, S Drellack, H Back, B J Bellgraph, M W Cooper, Michael FoxeAbstract:Pacific Northwest National Laboratory reports on the detection of 39Ar at the location of an underground nuclear explosion on the Nevada Nuclear Security Site. The presence of 39Ar was not anticipated at the outset of the experimental campaign but results from this work demonstrated that it is present, along with 37Ar and 85Kr in the subsurface at the site of an underground nuclear explosion. Our analysis showed that by using state-of-the-art technology optimized for radioargon measurements, it was difficult to distinguish 39Ar from the fission product 85Kr. Proportional counters are currently used for high-sensitivity measurement of 37Ar and 39Ar. Physical and chemical separation processes are used to separate argon from air or Soil Gas, yielding pure argon with contaminant Gases reduced to the parts-per-million level or below. However, even with purification at these levels, the beta decay signature of 85Kr can be mistaken for that of 39Ar, and the presence of either isotope increases the measurement background level for the measurement of 37Ar. Measured values for the 39Ar measured at the site ranged from 36,000 milli- Becquerel/standard-cubic-meter-of-air (mBq/SCM) for shallow bore holes to 997,000 mBq/SCM from the rubble chimney from the underground nuclear explosion.
C E Aalseth - One of the best experts on this subject based on the ideXlab platform.
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migration of noble Gas tracers at the site of an underground nuclear explosion at the nevada national security site
Journal of Environmental Radioactivity, 2019Co-Authors: Christine Johnson, T W Bowyer, James C Hayes, C E Aalseth, T R Alexander, V Chipman, S Drellack, J E Fast, Bradley G Fritz, Heather E HuckinsgangAbstract:Abstract As part of an underground Gas migration study, two radioactive noble Gases (37Ar and 127Xe) and two stable tracer Gases (SF6 and PFDMCH) were injected into a historic nuclear explosion test chimney and allowed to migrate naturally. The purpose of this experiment was to provide a bounding case (natural transport) for the flow of radioactive noble Gases following an underground nuclear explosion. To accomplish this, Soil Gas samples were collected from a series of boreholes and a range of depths from the shallow subsurface (3 m) to deeper levels (~160 m) over a period of eleven months. These samples have provided insights into the development and evolution of the subsurface plume and constrained the relative migration rates of the radioactive and stable Gas species in the case when the driving pressure from the cavity is low. Analysis of the samples concluded that the stable tracer SF6 was consistently enriched in the subsurface samples relative to the radiotracer 127Xe, but the ratios of SF6 and 37Ar remained similar throughout the samples.
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measurements of argon 39 at the u20az underground nuclear explosion site
Journal of Environmental Radioactivity, 2017Co-Authors: J Mcintyre, T W Bowyer, C E Aalseth, T R Alexander, V Chipman, S Drellack, H Back, B J Bellgraph, M W Cooper, Michael FoxeAbstract:Pacific Northwest National Laboratory reports on the detection of 39Ar at the location of an underground nuclear explosion on the Nevada Nuclear Security Site. The presence of 39Ar was not anticipated at the outset of the experimental campaign but results from this work demonstrated that it is present, along with 37Ar and 85Kr in the subsurface at the site of an underground nuclear explosion. Our analysis showed that by using state-of-the-art technology optimized for radioargon measurements, it was difficult to distinguish 39Ar from the fission product 85Kr. Proportional counters are currently used for high-sensitivity measurement of 37Ar and 39Ar. Physical and chemical separation processes are used to separate argon from air or Soil Gas, yielding pure argon with contaminant Gases reduced to the parts-per-million level or below. However, even with purification at these levels, the beta decay signature of 85Kr can be mistaken for that of 39Ar, and the presence of either isotope increases the measurement background level for the measurement of 37Ar. Measured values for the 39Ar measured at the site ranged from 36,000 milli- Becquerel/standard-cubic-meter-of-air (mBq/SCM) for shallow bore holes to 997,000 mBq/SCM from the rubble chimney from the underground nuclear explosion.
