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| 1 |
ID:
164682
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| Summary/Abstract |
Remote monitoring of krypton-85 from undeclared reprocessing of spent nuclear fuel could be part of a fissile material cut-off treaty, could serve as an additional measure for the IAEA safeguards system to monitor compliance with the Non-Proliferation of Nuclear Weapons Treaty, and could be an important verification tool of a reprocessing moratorium or Nuclear Weapon Free Zone in the Middle East or East Asia. Atmospheric transport modelling is applied to determine the area over which krypton-85 emissions from undeclared reprocessing activities at various levels in the Middle East would still be detectable against the high krypton-85 background from reprocessing in historical weapon programs in the United States and USSR as well as more recent and ongoing commercial reprocessing in France and the U.K. Analysis of annual wind flow over Israel's Dimona facility, the only operating reprocessing site in the region, suggests that a known reprocessing plant could be monitored with one or a few fixed monitoring stations. Random air sampling for krypton-85 analysis, perhaps using drones, may be feasible for reliable and timely detection of clandestine reprocessing plants against the krypton-85 background but would require on the order of 50–100 air samples per day. Ending reprocessing at La Hague in France and at Sellafield in the UK and the resulting decline of the krypton-85 background over time would reduce to about 10 the number of daily samples required to monitor the Middle East.
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| 2 |
ID:
135316
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| Summary/Abstract |
Radioxenon is an important atmospheric tracer to detect underground nuclear explosions. The International Monitoring System is designed to provide worldwide continuous physical monitoring and detection of nuclear explosions and incorporates 40 noble gas monitoring stations. They are constantly sampling the atmosphere for concentrations of radioxenon. This work analyses how effectively the network of stations is able to detect unusual xenon-133 concentrations in the atmosphere. A large multitude of nuclear explosions, evenly distributed in space and time, is simulated and the detection rate is calculated. Atmospheric transport modelling is applied to calculate the source-receptor-sensitivities for each monitoring station. The approach includes the anthropogenic radioxenon background, station-specific detection criteria, different scenarios for surface and subsurface nuclear explosions, and a spatial as well as a time dependent analysis. Recommendations are drawn for the improvement of the detection capability.
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| 3 |
ID:
157471
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| Summary/Abstract |
In 2013, the staff of the U.S. Nuclear Regulatory Commission estimated the reduction of the off-site economic losses from a fire in a drained U.S. spent fuel pool if fuel that had cooled for more than five years were transferred to dry cask storage--an option it called "expedited transfer." In this article, it is shown that the savings would be much higher than the NRC estimated. Savings increase to about $2 trillion if: losses beyond 50 miles are included; the land-contamination threshold for long-term population relocation is changed to that used for the Chernobyl and Fukushima accidents and recommended by the U.S. Environmental Protection Agency; and, based on the experience of Japan, decontamination of land areas to levels acceptable for population return is assumed to take at least four years. If expedited transfer were implemented, the off-site economic losses would be reduced by about 98%.
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| 4 |
ID:
149611
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| Summary/Abstract |
Tanks holding liquid high level waste from reprocessing spent fuel have large inventories of highly radioactive materials. These tanks could potentially be damaged by a variety of chemical explosions, leading to the dispersion of a significant fraction of their radioactive contents. This article describes some of the different chemical explosions that could occur and examines how such explosions could occur at the Kalpakkam Reprocessing Plant in India, which likely stores a large volume of high level liquid waste because vitrification of that waste did not begin until more than 15 years after the plant began operating in 1998. The atmospheric dispersion of the hypothetical radioactive release is modeled using the Hybrid Single-Particle Lagrangian Integrated Trajectory Model developed by the Air Research Laboratory of the U.S. National Oceanic and Atmospheric Administration. The results suggest that the modeled accident scenario would lead to nearly 97,000 cancers, with roughly 47,000 of these being fatal. Larger radioactive releases are possible and would lead to proportionately higher incidence of cancer and cancer-caused mortality.
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| 5 |
ID:
149610
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| Summary/Abstract |
This article reviews the case of the spent fuel fire that almost happened at Fukushima in March 2011, and shows that, had the wind blown the released radioactivity toward Tokyo, 35 million people might have required relocation. It then reviews the findings by the United States Nuclear Regulatory Commission (NRC) in 2013 that the consequences of a loss-of-water event could be drastically reduced if spent fuel were moved to dry storage after 5 years of pool cooling but that the probability of a spent fuel pool fire is too low to make this a requirement. Our atmospheric dispersion and deposition calculations using HYSPLIT for hypothetical releases from the Peach Bottom plant in Pennsylvania find average interdicted areas and populations requiring relocation larger than NRC estimates presented to the National Academy of Sciences (NAS) and support the NAS findings of errors and omissions in the NRC's cost-benefit calculations. Political pressures from industry on the NRC may be biasing its analyses toward regulatory inaction.
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