NRC requires new look at quake risks for nuclear reactors

photo The containment door of the Unit 2 reactor, opened for maintenance is 7 feet thick of reinforced concrete. Photo by Michael Mercier/ The Huntsville Times

The Nuclear Regulatory Commission later this year will provide nuclear plants with a seismic analysis software tool and require all of the nation's 104 reactors to assess their earthquake risks.

NRC announced the plan Thursday, two days after a 5.8 quake rattled the East Coast and shut down the North Anna nuclear facility near the quake's epicenter in Mineral, Va.

The plant declared an "alert" - the second-lowest of NRC's four emergency classifications - before regaining its electricity several hours later.

Another dozen nuclear power plants along the East Coast and upper Midwest declared an "unusual event," the NRC's lowest emergency classification.