The Nuclear Regulatory Commission addressed nuclear safety during a Sept. 12 hearing with the U.S. Senate Committee on Environment and Public Works. Since the March 2011 disaster at the Fukushima Daiichi nuclear power plant in Japan, an NRC-established task force has been working to determine lessons learned from the events in Japan and has made 12 recommendations to the agency to enhance safety and emergency preparedness at the 104 operating reactors in the U.S.
“The consequences of the terrible events in Japan have prompted us to rethink how to ensure safety at the 104 nuclear reactors in the United States,” said Senator and Committee Chairman Barbara Boxer, D-Calif.
The NRC recommendations have been organized in three tiers; Tier 1, Tier 2 and Tier 3. Tier 1 recommendations were developed with the mind-set that these actions should be started without delay and include, but not limited to, seismic and flood hazard reevaluations, station blackout regulatory actions and spent fuel instrumentation. Tier 2 recommendations are actions that could not be inititated in the near-term due to factors that include the need for further technical asseement, dependence on Tier 1 issues, or availability of critical skill sets. The actions can be initiated when sufficient technical information becomes available, according to regulators. These actions include spent fuel pool makeup capability, emergency preparedness regulatory actions and other external hazards reevaluation. The third and final Tier consists of actions that do requires further NRC study, and include ten-year confirmation of seismic and flooding hazards, emergency preparedness enhancements for prolonged station blackout and multiunit events and the transfer of spent fuel to dry cask storage, among other things.
In August, the NRC finalized guidance for plant operators to implement three orders issued in March 2012 in response to the recommendations made by the task force. The first order requires all U.S. plants to better protect portable safety equipment put in place after the 9/11 terrorist attacks and to obtain equipment to support all reactors and spent fuel pools at a given site simultaneously. The second order applies only to U.S. boiling-water reactors that have “Mark I” or “Mark II” containment designs. Mark I reactors must improve installed venting systems that help prevent core damage in the event of an accident; Mark II reactors must install these venting systems. The third order requires all plants to install enhanced equipment for monitoring water levels in each plant’s spent fuel pool. For all three orders, licensees are required to submit their plans for implementing these requirements to the NRC by Feb. 28, 2013, with a deadline to comply of Dec. 31, 2016.
“While on the one hand I am encouraged that the NRC has begun moving forward, I also have concerns that the Commission is allowing some nuclear plants to delay implementing safety improvements beyond the recommended five-year period,” said Boxer.
During her first hearing as NRC Chairman, Allison Macfarlane told Senators that while the commission continues to believe there is not imminent risk from continued operation of existing nuclear power plants, the NRC’s assessment of the events at the Fukushima Daiichi plant led the NRC to conclude that additional requirements should be imposed on licensees to increase the capability of nuclear power plants to mitigate the effects of beyond-design-basis extreme natural phenomena.
“We are making good progress on these issues,” said Macfarlane. “The NRC staff has done an outstanding job of not only making good progress on lessons-learned from Japan, but also on continuing to ensure the safe and secure operation of all our existing licensed facilities.”
Commissioner William Magwood said over the past 18 months since the disaster in Japan, the NRC has conducted thorough reviews. Magwood said he has met with regulators from around the world, as well as visited eight nuclear power sites in the U.S. He added that license have already purchased equipment, such as diesel generators and pumps, and that new procedures and training processes are being developed at plants.
“I am confident the steps we have taken have, and will continue to enhance nuclear safety,” said Magwood.
Macfarlane said the NRC has many issues to deal with right now, such as post-Fukushima safety enhancements, storage of spent nuclear fuel and licensing activities.
“As we look forward, the agency expects to meet new challenges,” said Macfarlane. “We are confident that the NRC will continue to ensure the safe and secure operation of the existing licensed facilities, and the safe and secure uses of radioactive materials, while also ensuring the safe and secure construction and operation of new nuclear power plants, possibly including small modular reactors and other nuclear facilities.”
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