The U.S. Nuclear Regulatory Commission on Wednesday formally rejected a petition to establish a rule requiring nuclear sites to evaluate and address seismic and flooding dangers once per decade.
The nongovernmental Natural Resources Defense Council filed the petition on July 26, 2011, just over four months after an earthquake and tsunami caused three reactors to melt down at the Fukushima Daiichi nuclear power plant in Japan.
“The petitioner requested that the NRC amend its regulations to require nuclear facilities licensed under 10 CFR parts 50, 52, and 100, and other applicable regulations, to confirm seismic hazards and flooding hazards every 10 years and to address any new and significant information, which would include, if necessary, updating the design basis for structures, systems, and components (SSCs) important to safety to protect against the updated hazards,” the NRC said in a Federal Register notice dated Feb. 6.
The Natural Resources Defense Council said it based the request on a recommendation from a post-Fukushima task force established by the NRC.
The agency denied the petition because there are avenues beyond rulemaking for addressing the recommendation, the Federal Register notice says. The commission has already signed off on a staff method for augmenting existing systems to ensure consideration of updated information regarding natural dangers to nuclear power plants, in line with the task force recommendation.
In January, the commission voted 3-2 to approve a separate post-Fukushima rule intended to increase safety at nuclear power plants. In their dissent, Commissioners Stephen Burns and Jeff Baran said the new rule fails to require that NRC licensees incorporate new data on flooding and earthquake dangers in plans for mitigating “beyond-design-basis” events.