SUMMARY FOR CONGRESS
The U.S. Congress asked the National Academies to provide independent scientific and technical advice on the safety and security of commercial spent nuclear fuel storage in the United States, specifically with respect to the following charges:
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Potential safety and security risks of spent nuclear fuel presently stored in cooling pools at commercial nuclear reactor sites.
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Safety and security advantages, if any, of dry cask storage versus wet pool storage at these reactor sites.
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Potential safety and security advantages, if any, of dry cask storage using various single-, dual-, and multi-purpose cask designs,
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The risks of terrorist attacks on these materials and the risk these materials might be used to construct a radiological dispersal device.
Congress requested that the National Academies produce a classified report that addresses these charges within 6 months and also provide an unclassified summary for unlimited public distribution. The first request was fulfilled in July 2004. This report fulfills the second request.
The highlights of the report are as follows:
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Spent fuel pools are necessary at all operating nuclear power plants to store recently discharged fuel.
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The committee judges that successful terrorist attacks on spent fuel pools, though difficult, are possible.
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If an attack leads to a propagating zirconium cladding fire, it could result in the release of large amounts of radioactive material.
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Additional analyses are needed to understand more fully the vulnerabilities and consequences of events that could lead to propagating zirconium cladding fires.
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It appears to be feasible to reduce the likelihood of a zirconium cladding fire by rearranging spent fuel assemblies in the pool and making provision for water-spray systems that would be able to cool the fuel, even if the pool or overlying building were severely damaged.
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Dry cask storage has inherent security advantages over spent fuel pool storage, but it can only be used to store older spent fuel
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There are no large security differences among different storage-cask designs.
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It would be difficult for terrorists to steal enough spent fuel from storage facilities for use in significant radiological dispersal devices (dirty bombs).
The statement of task does not direct the committee to recommend whether the transfer of spent fuel from pool to dry cask storage should be accelerated. The committee judges, however, that further engineering analyses and cost-benefit studies would be needed before decisions on this and other mitigative measures are taken. The report contains detailed recommendations for improving the security of spent fuel storage regardless of how it is stored.