A split Nuclear Regulatory Commission on Thursday narrowly signed off on a new rule intended to further protect U.S. nuclear power plants from a disaster akin to the March 2011 reactor meltdowns at the Fukushima Daiichi facility in Japan.
Commissioners voted 3-2 along party lines to approve the rule on mitigation of beyond-design-basis events. It will take effect 30 days after being published in the Federal Register, which is expected this spring.
The commission’s Republican members – Chairman Kristine Svinicki and Commissioners David Wright and Annie Caputo – said in their position statement that the rule effectively caps nearly eight years of work to improve nuclear power safety. The dissenting members, Democratic Commissioners Jeff Baran and Stephen Burns, argued it leaves out key elements including requiring licensees to incorporate newer data on flooding and earthquake hazards in mitigation plans for beyond-design-basis events.
Such an incident, per the NRC, would involve an event that was not comprehensively evaluated in designing a nuclear power plant due to the small chance it would ever occur.
The earthquake and tsunami that hit Japan on March 11, 2011, met the definition of a beyond-design-basis accident. They initiated a series of events that led to meltdowns and release of radioactive material at three reactors at Fukushima. More than 100,000 residents were evacuated from the surrounding area in the wake of the disaster and cleanup continues.
The incident led to a years-long program at the NRC intended to enhance nuclear power plant safety. The commission received the draft mitigation rule for consideration in December 2016, before Wright and Caputo joined.
The final rule approved Thursday will cover operational nuclear power sites, along with current and future license applicants. It places three central requirements on licensees:
- Sustain resources and procedures to ensure the reactor core and spent fuel pool remain cooled, and reactor containment is not undermined, even if the plant’s alternating-current power sources are crippled.
- Provide equipment to ensure spent fuel pool water levels can be measured after an incident.
- Provide resources necessary for safeguarding the reactor core and containment, along with the spent fuel pool, from external dangers.
The full cost of the rule is projected at about $110,000 per licensed site, according to the rule. That is down from $1.7 million per site in the draft version.
“The Commission’s action on this final rule provides a holistic conclusion to a large portion of [post-Fukushima safety] work, which has already resulted in undeniable safety improvements throughout the operating power reactor fleet in the United States,” Svinicki, Wright, and Caputo wrote in their “Views of the Commission.”
They noted that the effort is not completed, with analysis continuing on the need for further safety enhancements. “This work is being performed and will continue in the disciplined, site-specific processes that are in use and are appropriate for resolving these issues.”
But the vote quickly drew fire from the other two commissioners.
In his own “Views” report, Burns said the final rule will “significantly weaken what will be the agency’s most enduring action as a result of lessons learned from the Fukushima Daiichi accident.”
Specifically, the three-member majority has effectively dismissed a March 2015 decision by the commission approving a staff recommendation directing nuclear power plant licensees to reassess flooding hazards in their mitigation approaches for beyond-design-basis events, according to Burns.
The commissioners who voted in favor of the final rule said staff requirements memoranda of the type approved in 2015 should not be used to institute mandatory directives on nuclear power licensees.
Baran noted that the final rule eliminates certain requirements that had been included in the draft version: “an integrated response capability for beyond-design-basis events that includes the integration of the guidelines, strategies, and alternative approaches … with the existing emergency operating procedures; and includes training requirements, drills or exercise requirements, staffing and communications requirements, and the documentation of changes.”
The Washington, D.C.-based trade organization for the nuclear industry lauded the decision and U.S. nuclear power safety measures more generally. “Plants were designed to withstand the most severe hurricanes, earthquakes and other natural hazards as assessed by experts,” Maria Korsnick, CEO of the Nuclear Energy Institute, said in a prepared statement. “After their construction, more than $4 billion in additional equipment was added to protect against even more extreme events that were ‘beyond design basis.'”
However, a number of Democrats in Congress lashed the new rule. Sen. Edward Markey (D-Mass.), who over the years has peppered the commission with safety concerns about the soon-to-close Pilgrim Nuclear Power Station in his state, said he would “investigate this newly affirmed rule and hold the Commission accountable.”
“Instead of learning the lessons of the Fukushima nuclear disaster, we are ignoring them and imperiling the safety of Americans who live near nuclear reactors,” Markey said in a press release.
The majority of nuclear power plants will be required to be in compliance with the rule no more than two years and 30 days after publication of the Federal Register notice. Sites covered by a March 2013 NRC order on containment venting will be given an additional year to reach compliance.
The new rule will supersede prior orders on venting and mitigation strategies, along with directives included in new reactor licenses approved from 2012 onward.
