The seismic design criteria applied to siting commercial nuclear power plants operating in the  United States received increased attention following the March 11, 2011, earthquake and tsunami  that devastated Japan’s Fukushima Daiichi nuclear power station. Since the event, a magnitude  5.8 earthquake near Mineral, VA, on August 23, 2011, precipitated the temporary shutdown of  Dominion Power’s North Anna nuclear power plant. Some Members of Congress have  questioned whether U.S nuclear plants are more vulnerable to seismic threats than previously  assessed, particularly given the Nuclear Regulatory Commission’s (NRC’s) ongoing reassessment  of seismic risks at certain plant sites.