05/10/2011 - 06:40

Nuclear safety post-Fukushima: A victory for the public's right to know

Edwin S. Lyman

Edwin S. Lyman

A physicist, Lyman is a senior staff scientist in the Global Security Program at the Union of Concerned Scientists...

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How vulnerable are US nuclear reactors to the kind of disaster that is occurring at Fukushima Daiichi? Considering that one in three Americans lives within 50 miles of a nuclear plant, the public deserves access to all information that can shed light on this question. Yet a straight answer has been difficult to obtain from the Nuclear Regulatory Commission (NRC) and the nuclear industry. In the weeks following the accident, the NRC, rather than providing clear explanations, often resorted to its business-as-usual strategy: offering vague reassurances while muddying the waters with confusing bureaucrat-speak. And when all else failed, the NRC dropped a veil of secrecy over information that could cast doubt on -- or even contradict -- some of its public assertions.

This was evident when the NRC and the industry invoked the mysterious requirements known as "B5b" as a cure-all for the kinds of problems that led to the Fukushima crisis. B5b refers to a section of an NRC Order, issued in February 2002, describing the strategies that the NRC required nuclear plant licensees to develop after the September 11 attacks to "maintain or restore core cooling, containment, and spent fuel pool cooling capabilities under the circumstances associated with loss of large areas of the plant due to explosions or fire." The NRC decided to impose these rules instead of requiring nuclear plants to adopt measures that would help to prevent aircraft attacks on nuclear plants through means such as no-fly zones, anti-aircraft weapons, or construction of additional physical barriers.

Even though the B5b strategies were specifically developed to cope with fires and explosions, the NRC now argues that they could be used for any event that causes severe damage to equipment and infrastructure, including Fukushima-scale earthquakes and floods. However, given Japan's demonstrated lack of success in using after-the-fact measures to prevent a massive radiation release and to cool down the reactors and spent fuel, one may wonder whether NRC's measures would work any better. Until May 4, members of the public weren't able to figure this out for themselves because the NRC considered B5b measures to be "security-related information" that was too sensitive for general release. After all, terrorists shouldn't have access to plant operators' playbooks for controlling the damage caused by an attack. However, because the NRC began to claim that B5b can deal with accidents and natural disasters, the veil of secrecy was also getting in the way of the public's understanding of nuclear safety. Now, however, the NRC has released a guidance document describing how the B5b requirements could be met.

It appears that the NRC has now recognized that while it is appropriate to conceal the specific details about how a particular plant complies with B5b -- such as equipment specifications and locations -- the release of generic guidance does not pose a significant security risk, and is very helpful in informing the public about the benefits and limitations of these strategies.

Now that NRC has granted full access to the B5b guidance, the public can evaluate for itself whether the NRC was previously cherry-picking the release of information to support its safety claims. NRC has publicly described some of the B5b measures that could be brought to bear in the event of a Fukushima-type disaster, including pre-staging diesel-driven fire pumps to inject water into reactor cores or spent fuel pools if all power is lost. Another example is a procedure for manual operation of the Reactor Core Isolation Cooling (RCIC) system in the event of loss of all grid and backup power at a boiling water reactor. While the NRC implied that B5b strategies would be effective during a Fukushima-type event, it had refused to publicly document those claims.

For instance, at an NRC briefing on Fukushima on April 28, NRC Commissioner George Apostolakis asked a member of the staff: "Did you consider [a] major catastrophe and what it could do to the B5b equipment?" The answer: "The B5b was the response to an event that involved explosions and fire, so that was generally the focus of what was looked at in developing the mitigating strategies that would meet the requirements. We can discuss it further in the closed session." The now-released B5b guidance states that "prediction of precise damage states, plant conditions, and associated plant response is not possible, even on a site-specific basis," and also that "identified response capabilities will not ensure success under the full spectrum of potential damage states." This sounds a lot less confident than some of the NRC's public statements.

And does protection against explosions and fire necessarily imply protection against earthquakes, floods, and other situations with prolonged lack of access to off-site supplies? Apparently not. In the now-released document, one of the key assumptions is that "equipment associated with the external strategy is not to be treated as safety-related equipment. As such, it is not subject to any new special treatment requirements under 10 CFR (e.g. QA [quality assurance], seismic, EQ [environmental qualification], etc.)." It is unclear how the industry could therefore take credit for such equipment as a strategy for dealing with earthquakes or other natural disasters.

The guidance also requires that emergency diesel-driven pumps for providing coolant to spent fuel pools need only have sufficient fuel and water to operate for 12 hours at the required water flow rate. This would be clearly inadequate to deal with a Fukushima-like crisis.

The NRC continues to withhold important information about how effectively US nuclear plants are complying with the B5b requirements. During the April 28 NRC briefing, Commissioner William Ostendorff asked whether there were any lessons to be learned from the initial implementation of B5b at US plants. The answer again was deferred to closed session. But the NRC staff could have just as well pointed to a publicly available version of an Interim Staff Guidance (ISG) document known as ISG-16. The heavily redacted document points out that "at many sites the [B5b] guidance was incomplete, erroneous, or inadequate which called into question the quality of the validation of these procedures or whether verification and validation were performed," and also that "during inspections at licensed power reactor facilities, the NRC staff found that some licensees had not established a maintenance program for equipment relied upon to implement strategies. A few licensees did not even test portable pumps required for some strategies." The NRC says that all these problems have been fixed now, but these reports hardly engender confidence.

The public got another glimpse behind the secrecy curtain when the Union of Concerned Scientists, under a Freedom of Information Act request, received internal NRC e-mails showing that some NRC staff question the feasibility of B5b measures -- such as the manual operation of RCIC pumps. At Fukushima, the RCIC pumps were apparently able to provide cooling water to two of the reactors until the batteries ran down (within eight hours), after which time fuel overheating and damage occurred. The NRC told members of Congressman Henry Waxman's staff that, thanks to B5b, this situation would have been avoided at a US boiling water reactor because operators would have been able to manually operate the RCIC pumps, avoiding a core meltdown with an hour to spare. But one of the e-mails indicated that manual RCIC operation and other B5b strategies "have really not been reviewed to ensure that they will work to mitigate severe accidents."

There is good reason to be skeptical. In practice, manual RCIC operation would be very difficult because personnel would need to physically open and close valves in a room in the reactor building with no ventilation and no lights, and to measure the water level in the reactor vessel without any electrically powered instrumentation available. Now we know that the B5b guidance document states: "Implementation of this [B5b] strategy is not expected to require extraordinary or heroic actions. In any event the utility emergency response organization will decide on the potential benefit and feasibility of the strategy in light of plant conditions … it is expected that dose rates and other accessibility considerations will be addressed at the time of the event." Thus the guidance itself acknowledges that no one may know how well these strategies will work until after an accident happens.

The NRC has done a public service by releasing the B5b procedures, warts and all, so that Americans can judge the adequacy of these procedures for themselves. Additional information is needed, however, to independently assess whether US plants are better prepared than their Japanese counterparts to withstand a Fukushima-type event.