Jeremy L. Dillon
RW Monitor
1/10/2013
A majority of the Nuclear Regulatory Commission voiced support, or indicated through their questioning, that expedited transfer of spent fuel pools to dry cask storage is not needed during a briefing held this week to discuss the NRC’s staff’s findings on the subject. The NRC’s draft study on spent fuel pools, released in June, concluded that U.S. spent fuel pools were not in danger from severe earthquakes and that calls for moving the spent nuclear fuel to dry casks would not provide any “substantial safety enhancements.” “The staff says it’s not worth it,” Commissioner George Apostolakis said. “The Advisory Committee on Reactor Safeguards says we agree. The statistical evidence says these pools are very robust. Minor damage here or there under very strong earthquakes. Why would I go against the staff’s recommendation with this evidence?” he challenged a panel questioning the study.
The briefing featured representatives from both sides of the issue. Representing the industry, Dominion Nuclear President and Chief Nuclear Officer Dave Heacock agreed with the staff’s findings citing the minor safety benefits gained compared to the rising costs as well as praising the mitigation strategies the industry has adopted since Fukushima. However, Gordon Thompson, executive director of the Institute for Resource and Security Studies, criticized the NRC’s staff’s research because “it only looked at small portion of incidents that could affect loss of water.” Thompson felt the study did not reflect accurate science, and therefore, should be scrapped.
Much of the support for the study came via the consistency of regulations the study showed. Commissioner Ostendorff offered his support to the NRC staff study under this guise. “I would comment that it’s important for us as a regulator to adhere to our principles of good regulation,” Ostendorff said. “Predictability and stability of regulatory processes is a very essential element of that. And in that light, I think the staff has done a very credible job in reflecting Commission policy in its application of the quantitative health objectives QHO analysis in this paper.” Apostolakis argued that this was a regulatory decision, not an academic paper, so it did not have to follow the same guidelines. “These studies should not be reviewed as academic papers where you can make all sorts of comments about details here and there,” Apostolakis said. “You should have studied this. You should have studied that. It’s a regulatory decision we’re making here and you have to give me a reason that would upset that decision, not something that will make the study better.”
NRC Chairman Allison Macfarlane seemed to remain impartial in her questioning. Before her appointment as NRC Chairman, Macfarlane had previously written a paper in 2003 that criticized long-term spent fuel pool storage. Her co-author on the paper, Thompson, was part of the panel who criticized the study during the briefing.
Cost vs. Benefit Debate
One of the major areas of debate concerned the cost of spent fuel transfer compared to the relative safety benefit the transfer would add. The NRC staff found that the added small safety benefit did not outweigh the costs of transfer. Christine King, director of Nuclear Fuel and Chemistry at Electric Power Research Institute, estimated that the cost of expedited transfer would be $3.5 billion, an amount broken down for a single plant of $20 to $30 million. “The NRC staff, and correctly so, used multiple layers of conservatism in their analysis,” Heacock said. “Each layer was designed to favor expedited fuel off load. Even with all those conservatisms added and the favorability added to it, it didn’t really result in any change here.” Heacock would go on to add that the probability of an accident occurring was so small in some circumstances that it was “basically zero.”
Thompson argued that the spent fuel pools will have to be transferred at some point so there really is not any added cost. “Now this transfer is going to occur anyway when the reactors are shut down in the absence of a repository or a centralized store, thus the incremental cost of acting now is simply the time value of the transfer cost,” Thompson said.
Security Issues
Another major area of critique centered on the security of the pools from actions of terrorism. Those calling for the expedited transfer warned that these pools were attack targets for terrorists, and the NRC staff did not adequately address terrorism concerns in its study. “However, if you look at those declarations carefully, I believe you’ll conclude that an attack achieving a spent fuel pool fire is within the capability of non-state actors,” Thompson said. “The probability of this event is numerically indeterminate, but I submit that it is significant.”
Ostendorff disagreed with these criticisms, citing his extensive background in nuclear security. “I feel the need as a Commissioner here at a public meeting to state that I respectfully disagree with your statement of the concern on terrorist attack because your statement leads one to believe there are no precautions being taken from a physical security perspective,” he said. “I think there’s a significant body of protection that’s classified that does provide very robust physical protection for the spent fuel pools which are part of the protected area of our licensees.”
Macfarlane agreed that terrorism was a real threat that needed to be addressed in the analysis. “So with all due respect to Commissioner Ostendorff, I think that for completeness of study if you are going to consider precursors to an event at a spent fuel pool, one should consider all potential precursors and if terrorism is one, that should be considered,” Macfarlane said. “Of course, with all the understandings of the security that exists at reactors, etcetera. But that should be part of the analysis.”
Mitigation Strategies
The question of mitigation the spent fuel pools also led to some difference of opinions. Commissioner William Magwood thought the study offered some new realizations that supported the spent fuel pools. ”I think that the study, while it certainly, you know, isn’t unassailable, does provide some interesting new information which I think is worth reflecting on,” Magwood said. “And for me one thing that was kind of an interesting ‘aha’ moment; and I’ve talked to staff about this quite a bit, was the analysis showing that the presence of the cooler fuel in conjunction with the hotter fuel, and the 1×8 configuration particularly, act as a heat sink and actually mitigated the probability of a spent fuel fire. And that’s something that really hadn’t come up before. So while, you know, there is some criticism of the study, I think there are some new facts that really have not been discussed before,” Magwood said.
These new findings did not sway those against the study, though. “The staff has looked at only a small fraction of the possible scenarios that could lead to loss of water in the event of an accident or an attack,” Thompson said. “So there’s a large number of scenarios that are just not addressed at all in staff analysis to date.”