nuclear-news

WASHINGTON  —The Nuclear Regulatory Commission’s (NRC) Republican majority, in a 3-2 vote, approved a stripped-down version of a rule originally intended to protect U.S. nuclear plants against extreme natural events, such as the massive earthquake and tsunami that triggered meltdowns at the Fukushima Daiichi nuclear plant in Japan in March 2011.

The commission majority struck a provision from the draft final rule the NRC staff recommended in December 2016 requiring plant owners to protect their facilities from the real-world hazards they face today instead of “design-basis” hazards that were estimated using now-obsolete information and methodologies when the plants were built decades ago.

The commission majority’s act will leave unresolved how the NRC will address new information showing that plants may experience bigger floods and earthquakes than they are now required to withstand. It is possible that the commission will not require all plant owners whose facilities face greater hazards to make structural upgrades.

“Nearly eight years after the Fukushima accident, the NRC continues to disregard a critical lesson: Nuclear plants must be protected against the most severe natural disasters they could face today—not those estimated 40 years ago,” said Dr. Edwin Lyman, senior scientist and acting director of the Nuclear Safety Project at the Union of Concerned Scientists.

After Fukushima, an NRC task force recommended that the NRC “order licensees to reevaluate the seismic and flooding hazards at their sites … and if necessary, update their design basis and SSCs [structures, systems and components] important to safety to protect against the updated hazards.”

To date, the NRC has only implemented the first part of the recommendation: Owners have reevaluated seismic and flooding hazards. What they found is not reassuring. For instance, the flooding reevaluations revealed that roughly two-thirds of U.S nuclear plants face hazards beyond what they were originally designed to handle, including higher flood levels from  extreme precipitation, upstream dam failure and storm surge. The reevaluated flood height for local intense precipitation for the Palisades plant in Michigan, for example, was more than 25 feet higher than the level considered in the plant’s original design. Similar concerns were identified in many seismic risk evaluations.

Despite these findings, the NRC failed to implement the second part of the task force recommendation to require plant owners to strengthen their defenses against greater hazards. The rule that was approved today was originally intended to close that gap. The commission majority’s action today removed that requirement and will simply maintain the uncertain—and inadequate—status quo.

“The NRC must require plant owners to upgrade their facilities based on the best current information, the most realistic analyses, and the potentially devastating impacts of increased flooding from climate change,” said Dr. Lyman. “Failing to do so will leave some nuclear plants dangerously unprepared and needlessly invite disaster.”