By Jeff Beattie
In a substantial policy change that could slow some nuclear projects, the Nuclear Regulatory Commission (NRC) last week significantly toughened existing requirements that new U.S. reactors be designed to withstand the impact of large commercial aircraft.
The NRC dropped previous regulatory language requiring reactor designers to merely show that they incorporated features that would “mitigate” the effects of an aircraft collision “to the extent practical.”
In place of that language, the new draft final rule sets specific performance criteria requiring that reactor vendors show that their design includes features that will keep the reactor core cooled in the event of an aircraft collision, or that the reactor containment shell will remain intact to contain radiation released from a breach of the reactor’s core.
Separately, reactor designers will have to show that a plant’s spent fuel cooling systems would remain intact after an aircraft collision, or that the spent fuel pool integrity would be maintained and no radiation would be released into the environment.
The new rule may slow the already complex NRC review process for new reactors by adding a new variable. While reactor vendors say their designs already meet the new NRC airplane protection requirements, they now must go through the time-consuming process of proving to NRC their designs will prevent specific accidents.
NRC Chairman Dale Klein and commissioners Peter Lyons and Gregory Jaczko voted to approve the change, while Commissioner Kristine Svinicki opposed it, according to a vote sheet released by the commission Tuesday.
Among other arguments, Svinicki noted that members of the commission at the time the rule was proposed did not support mandatory acceptance criteria. She also noted that NRC has long said the federal government, not individual plant owners, bore primary responsibility for defending against events like airplane attacks.
That marks the second time the aircraft rule has been tightened in recent months. In October, NRC revised a draft of the rule to cover not only new reactor designs that are under NRC review, but also designs that NRC has already approved.
For reactor designs already approved, however, reactor vendors are off the hook for complying with the new aircraft impact rule. In the case of already-approved reactors, utilities seeking to build them will be responsible for showing compliance as part of their combined construction and operating license.
From among the 17 new reactor applications that NRC has received in recent months, the October change in airplane protection requirements appears likely to affect only NRG Energy‘s plan to build two advanced boiling water reactors (ABWR) at the South Texas Project near Bay City.
Unlike most of the other reactors utilities are planning to build, the ABWR has received NRC approval.
One other exception–Westinghouse‘s AP1000 pressurized water reactor–has received design certification but is under NRC review for a license amendment that would require the tougher aircraft impact protection even without the October rule change, NRC officials say.
From among the reactors that NRC is currently reviewing, sources say Areva‘s EPR may have a leg up on the competition because it was clearly designed to withstand aircraft attacks and is currently being built in a country–Finland–that requires that level of protection to be built into the design.
GE-Hitachi Nuclear Energy (GEH) says its Economic, Simplified Boiling Water Reactor (ESBWR), which is also under NRC certification review, complies with the new aircraft protection requirement.
“GEH has been aware for some time that the NRC would issue a final rule on new reactor aircraft impact assessments,” GEH said in a statement Wednesday. “As a result, we have been working on an analysis of our ESBWR design. GEH’s ESBWR design will meet the requirements of the rule.”
Mitsubishi Heavy Industries also has a design, known as the U.S. Advanced Pressurized Water Reactor (U.S.-APWR), under NRC certification review.
A Mitsubishi spokesman said Friday that its new design already complies with the new NRC requirement. “Yes, the U.S.-APWR was designed to this standard because everybody knew that this [the NRC policy change] was coming,” said company spokesman Pat Boyle.
From an NRC perspective, Tuesday’s vote was a clear victory for Jaczko, who has pushed hard to have mandatory requirements folded into the aircraft rule.
Early in the crafting of the rule, Jaczko suggested that toughening NRC’s protection requirements was not unreasonable, noting Finland already had set clear airplane impact standards for its new reactors.
In a statement, Klein acknowledged the commission “did not always agree on every element of this rule.” In particular, he said it would have been okay to retain the language allowing companies to include aircraft mitigation measures “to the extent practical.”
“Retaining language that would have required designers to adopt design features ‘to the extent practicable’ would have conveyed more clearly that costs may appropriately be considered when determining whether various mitigating design features identified as a result of an aircraft impact assessment are required to be implemented,” Klein said.
Ultimately, however, Klein said he was pleased “overall…with the expected outcome of the rulemaking.”
Klein credited late NRC Commissioner Edward McGaffigan, who passed away in September 2007, with significantly guiding the commission towards consensus on the matter.