U.S. Nuclear Regulators Defer Decision on Vent Filters

The Nuclear Regulatory Commission has delayed a final decision on requiring filters for emergency vents on the 31 U.S. nuclear reactors that are  similar in design to those at Japan’s ill-fated Fukushima Daiichi.

NRC staff experts earlier concluded the vents should be outfitted with filters, even though the chance of a failure that would require their use  is extremely small. But the NRC commissioners decided Tuesday on a 3-2 vote to defer  a final decision on the filters for at least another year for more study and public comment.  (See related, “Safety Question on Fukushima Anniversary: Should Plants of the Same Design Have Filtered Vents?“)

The decision is a victory, at least for the time being, for the nuclear power industry, which has agreed to upgrade vents on the reactors, but has resisted the filters. The  filters can’t be justified under normal cost-benefit analysis. But in nuclear regulation, there are some safety measures that are not subject to a cost-benefit approach; they are simply deemed necessary. The filter debate centers around the question of whether this is a measure that falls in that category of costly but essential protection. (Related Quiz: “What Do You Know About Nuclear Power?“)

When Fukushima Daiichi lost power in the wake of the March 2011 earthquake and tsunami and the meltdown began, the build-up of hydrogen gas caused an explosion that destroyed the containment buildings and resulted in the release of radiation. (Related: “Japan Reactor Crisis: Satellite Pictures Reveal Damage“)

Filters are required on these reactors in Europe, and have been required since last year in Japan. An upgrade of vents is underway now at U.S. plants, with completion scheduled for the end of 2016. Estimates on additional costs for filtering the vents vary, but the industry uses a figure of $15-20 million each.” (Related: “Photos: Rare Look Inside Fukushima Daiichi“)

The NRC is designed to be a bipartisan regulatory body, with the majority from  from whichever party holds the White House. In the vote yesterday, one Democrat joined the Republicans in deciding  to defer a decision on the filters pending further study. Following word of the vote, California Democratic Senator Barbara Boxer issued a statement critical of the NRC’s decision.

“The Nuclear Regulatory Commission should never cut corners when it comes to safety, especially after Fukushima,” she said. “We should accept the recommendations of safety experts and not just accept a partial fix.”

Alex Chadwick is the host of the public radio series, BURN: An Energy Journal, from SoundVision productions and American Public Media’s Marketplace, produced with funding from the Alfred P. Sloan Foundation.