Released late yesterday by NRC:
The U.S. Nuclear Regulatory Commission (NRC) today unveiled the third in a series of major steps to enhance the post-Sept. 11 security of nuclear power plants. The agency proposal would require each applicant for a new reactor design to assess how the design, to the extent practicable, can have greater built-in protections to avoid or mitigate the effects of a large commercial aircraft impact, making them even more resistant to an attack.NEI spokeman Steve Kerekes passed along the following note in response:
The Commission emphasized that seeking security assessments and examining how designs can be improved is consistent with the traditional approach the NRC has taken to so-called “beyond design basis events.” These are events with conditions exceeding the stresses imposed by the “design basis event” conditions which require plants to be brought to a safe shutdown. Design basis event conditions include large pipe breaks, fires, earthquakes, hurricanes, tornados and floods. Assessing a new reactor design in the early stages can enable modifications or additional features to reduce the need for human intervention in the event of an airplane crash.
The NRC will seek comment from the public, the nuclear industry and the technical community on the proposal. The proposed rule, which will replace an NRC staff proposal, will be available for comment later this year.
While we've not seen details beyond the news release at this point, the Commission's action strikes us as appropriate. It will properly assure that, as is the case with other potentially serious events like extremely severe hurricanes and earthquakes (we already design for some of these, of course), aircraft impacts are examined early on as part of the design process.More later, if warranted.
A great deal of security-related activity at nuclear plants the past five years has centered on steps to mitigate the effects of events like aircraft impacts. This action will enhance the defense-in-depth philosophy that is used in designing these new facilities -- which due to advanced designs will have even higher margins of safety than the 103 nuclear plants operating in the United States today.