Thursday, February 19, 2009

Final Rule On Aircraft Impacts For Nuclear Power Reactors

Feb 17: The U.S. Nuclear Regulatory Commission (NRC) has issued a final rule that requires applicants for new power reactors to assess the ability of their reactor designs to avoid or mitigate the effects of a large commercial aircraft impact. NRC Chairman Dale Klein, said, “This is a common sense approach to address an issue raised by the tragic events of Sept. 11, 2001. I am quite confident that this rule will be an important element in the regulatory framework for new reactor applications that will result in a margin of safety far beyond that required to achieve reasonable assurance of public health and safety.” [emphasis in original]

NRC said in a release that nuclear power plants are designed under very stringent requirements to assure they can safely shut down following “design-basis events” such as large fires, floods, earthquakes and hurricanes, as well as improbable equipment malfunctions including pipe breaks. These requirements include having two redundant systems to accomplish each safety function. The rule treats large commercial aircraft crashes as "a beyond-design-basis events." Under the rule, any design feature or functional capability adopted solely to comply with the rule will meet high quality standards but is exempt from NRC design-basis regulations, such as regulations for redundancy. The design features and functional capabilities must address core cooling capability, containment integrity, spent fuel cooling capability, and spent fuel pool integrity following an aircraft impact.

The release indicates, "The agency does not believe nuclear power plant operators should be required to prevent the impact of large commercial aircraft; that responsibility rests with the federal government. The NRC works closely with other federal agencies such as NORAD, the Federal Aviation Administration and the intelligence community to provide layered protection against such a threat. The agency expects these efforts would effectively preclude an aircraft attack from occurring. Should such an unlikely event take place at a new plant designed in accordance with the new rule, the NRC expects the plant would be better able to withstand such a crash than the same design without changes resulting from the rule."

Access a release from NRC (
click here). Access an October 15, 2008 draft of the final rule with a information on the purpose, summary, background, discussion, commitments, recommendations and resources (click here). Access the February 17, 2009, NRC final action on the rule, with comments and edits (click here). Access a 4-page issue brief from the Union of Concerned Scientists on New Reactor Designs for Aircraft Threats (click here).