Nuclear reactors in the U.S. may not be as safe from earthquakes as previously thought. Revised estimates of earthquake risk have led at least two dozen nuclear reactor facilities to inform the Nuclear Regulatory Commission (NRC) that their facilities may not withstand the most severe earthquake they could possibly face. As a result, these reactors must undergo costly new safety assessments that may cost up to $5 million per reactor.

The NRC required companies to reassess earthquake risk following the2011 Japanese Tohoku earthquake and subsequent triple meltdown of reactors at Fukushima Daiichi.

So far the NRC has assumed that reactors built to previous specifications do not pose an immediate threat. An NRC spokesperson indicated that reactors that experience earthquakes stronger than they were designed to withstand will not necessarily sustain serious damage. Senator Edward Markey (D-MA) encouraged the NRC to take immediate action to secure at-risk reactors instead of recommending more studies.

Sources: E&E News, New York Times