"Alert" declared at North Anna and "Unusual Events" at 12 more nuclear power plants due to earthquake

The U.S. Nuclear Regulatory Commission has issued a media release re: the Virginia earthquake, stating it is monitoring conditions at the North Anna nuclear power plant, located very close to the quake's epicenter in Mineral, VA. North Anna nuclear power plant has declared an "Alert," the second of four levels of increasing risk and severity.  The media release also states:

"Plants declaring Unusual Events, which indicate a potential decrease in plant safety, include Peach Bottom, Three Mile Island, Susquehanna and Limerick in Pennsylvania; Salem, Hope Creek and Oyster Creek in New Jersey, Calvert Cliffs in Maryland, Surry in Virginia, Shearon Harris in North Carolina and D.C. Cook and Palisades in Michigan. All these plants continue to operate while plant personnel examine their sites."

The 12 plant sites comprise 19 atomic reactor units. Peach Bottom 2 & 3, Hope Creek, and Oyster Creek are General Electric Boiling Water Reactors of the Mark 1 design, essentially identical to Fukushima Daiichi Units 1 to 4, devastated by an earthquake and tsunami beginning on March 11th. Limerick is comprised of two GE BWR Mark 2 design reactors, where containment buildings NRC now concedes are too small and risk failure under severe accident conditions. The risk is so high that the agency is recommending that operators install "hardened vent" systems to save the structures from rupturing, although this would still result in radioactive steam releases during an emergency, albeit "smaller," "controlled" ones. Similarly, it was the retrofitted vents installed at Fukushima that failed to protect  the primary containment in the severe accident following the Eastern Japan Earthquake and Tsunami.

The Washington Post has reported on this story.