The following post is from Ed Lyman, senior scientist at the Union of Concerned Scientists
Following the March 11, 2011, nuclear accident at the Fukushima Daiichi nuclear plant in Japan, the Nuclear Regulatory Commission (NRC) set up a task force to identify the lessons the U.S. nuclear industry should learn from the accident to avoid something similar here. Two years later, where does that effort stand to make U.S. reactors safer?
There is no question that the NRC and the nuclear industry have taken steps to address some of the safety vulnerabilities revealed by the Fukushima disaster. But it is far from clear whether those steps will be sufficiently robust to prevent the next disaster.
The NRC Task Force developed a set of recommendations and divided them into three categories based on their level of urgency. Since then, the agency has begun to implement some of the more straightforward recommendations, such as requiring plant owners to install instrumentation to monitor the status of spent fuel pools during an accident, install reliable hardened containment vents, and reevaluate seismic and flooding risks.
But dealing with the bigger issues is taking longer, and so far the response by both the NRC and the industry has been inadequate.
After Fukushima, the task force recommended, among other things, that nuclear plants upgrade their emergency response plans to be able to keep reactor cores or spent fuel pools from melting down in the event of an extended loss of electrical power (called a station blackout) or other severe events. Soon afterward, the industry rolled out its own response plan, dubbed Diverse and Flexible Coping Strategies (FLEX), which calls for plant owners to buy additional emergency cooling equipment, including portable pumps and power supplies, and stockpile it at reactor sites and two regional distribution centers. The rationale for FLEX is that if enough equipment is scattered in enough different locations, there would be working equipment available in the event of an emergency, no matter what calamity befell the plant and its surroundings. The basic concept is “more pumps,” but not necessarily “better pumps.”
Last year, the Union of Concerned Scientists (UCS) expressed misgivings about the FLEX program. Nuclear plants around the country began to acquire hundreds of pieces of off-the-shelf equipment on a voluntary basis before the NRC formulated its own requirements for the equipment and the strategies to use it. UCS feared that the industry was creating a fait accompli that would make it difficult for the NRC to require a significantly different or more stringent approach.
Today, it is clear that UCS had good reason to be apprehensive. The NRC, with minor exceptions, endorsed the industry’s FLEX program as an acceptable way for plant owners to comply with the agency’s March 2012 order for plants to develop interim plans to cope with an extended station blackout. To its credit, the NRC required that licensees develop detailed procedures for implementing FLEX strategies. These plans, however, have deviated from the original task force recommendations in important ways.
For example, the task force recommended that nuclear plants be capable of withstanding a station blackout for eight hours without using portable FLEX-type equipment—an explicit recognition of the difficulties Fukushima workers had setting up and using such equipment. The task force also recommended that the portable equipment be capable of functioning for three days without off-site support, again an explicit recognition that there may be practical difficulties accessing a plant site after a major disaster. Regardless, the industry’s FLEX guidance, as approved by the NRC, does not have any set minimum timelines, leaving the possibility that it could be considerably more lax than the task force recommendations.
That would be counterproductive, especially since the task force recommendations on these two issues are not strong enough. Nuclear plants should be able to withstand a station blackout for 24 hours without using portable equipment and be able to function for seven days without off-site support.
Another issue is how the industry protects the FLEX equipment. The task force recommended that plant owners store the equipment well above the maximum predicted flood levels at each plant, recognizing that flood predictions are uncertain. But the FLEX program has no such requirement, ignoring one of the major lessons of Fukushima: Plant owners need to be prepared for the unexpected. The FLEX program’s “more pumps, not better pumps” strategy could result in plant owners having more unusable pumps during a crisis.
The NRC recently told Congress that it had considered and rejected a proposal that plant owners install “dedicated bunkers with independent power supplies and cooling systems.” UCS believes this approach, which France is instituting, deserves more serious consideration.
UCS’s concerns about FLEX were heightened recently when the NRC suggested it may be willing to consider the program not just as a short-term, stopgap measure but as an official, long-term strategy to address station blackout risks. The agency originally planned to develop a new rule on an expedited basis to require plants to cope with extended station blackouts. This is important because a rulemaking, unlike an agency order, provides more opportunity for public comment. But the agency recently decided to delay the station blackout rulemaking for two years, postponing the process that would allow the FLEX program’s problems to get a wider and more public review.
The industry has also argued against the NRC staff’s recommendation that Mark I and Mark II boiling-water reactors install filters on their containment vents, claiming that they can reduce the risk of radioactive releases during a severe accident by just using FLEX equipment and strategies. But given all the uncertainties about the reliability of FLEX, their proposal is not an adequate substitute for the installation of filters.
The NRC is delaying other critical post-Fukushima initiatives. For example, the agency immediately put the task force’s top recommendation to fundamentally revise how the NRC regulates severe accidents, on the back burner. Now the staff has asked for even more time to develop an approach. Likewise, the NRC also has delayed reviewing spent fuel safety risks, a vital addition to the public debate, and has postponed any decisions about expanding emergency planning zones for years.
The NRC’s task force identified important issues the NRC and U.S. nuclear industry must address to ensure that reactor safety lapses do not result in a nuclear disaster. And yes, there has been some progress two years after Fukushima. But the NRC has been tentative while the industry and Congress is pressuring it to slow down implementing safety reforms. As the NRC moves forward, it needs to be wary of considering half measures as progress if they fail to adequately address underlying problems. The health and safety of the 111 million Americans who live within 50 miles of a nuclear plant hang in the balance.
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