A day after an unusual earthquake in Virginia, the NRC continues to assess operations at the North Anna nuclear power plant, which is a few miles from the epicenter.
The plant had originally declared an Alert, the second-lowest of four emergency classifications, when it lost electricity from the grid following the quake just before 2 p.m. yesterday. North Anna’s onsite diesel generators provided power to the plant’s safety systems until grid connections were restored at approximately 5:40 p.m. that same day.
The plant downgraded to an Unusual Event at approximately 11 a.m. today, before canceling its emergency declaration altogether.
North Anna personnel are currently assessing the plant’s normal operating systems and structures. The NRC’s resident inspectors at the plant are observing the plant’s activities and providing first-hand information to the agency. In light of the quake’s strength and proximity to the plant, the NRC will soon decide whether to conduct a follow-up inspection, aimed at determining how the quake compares to what the plant was designed to withstand.
The NRC also contacted Eastern U.S. industrial and medical facilities that possess significant quantities of nuclear materials. All of these locations confirmed their materials are secure.
Twelve other Eastern U.S. nuclear power plants had declared Unusual Events while they examined their sites immediately following the quake. All 12 had canceled their event designations by yesterday night and all continue to operate normally.
Nuclear power plants are built to withstand environmental hazards, including earthquakes. Even those plants that are located outside of areas with extensive seismic activity are designed for safety in the event of such a natural disaster. The NRC requires that safety-significant structures, systems, and components be designed to take into account the most severe natural phenomena historically reported for the site and surrounding area.
The NRC is also continuing a multi-year effort to have U.S. nuclear power plants use advanced methods and updated seismic information to re-examine how the plants would respond to earthquakes.
Scott Burnell Public Affairs Officer
U.S. NRC Blog 
The safe and ongoing generation of electrical power is a concern to all of us. I continue to be amazed at how politicized this is, despite the fact that in this day, electricity is as much a right and essential for our society to function as the freedom to vote. But nuclear generation of electrical power seems to be the fall guy again and again. When will we ever learn?
I noticed there was no schedule for predicted start-up in this statement.
As the NRC recently outlined in a statement on the agency website, “The NRC requires U.S. reactors to withstand a predicted level of ground motion, or acceleration, specific to a given site. Ground acceleration is measured in relation to “g,” the acceleration caused by Earth’s gravity.” In other words, plants are designed to site-specific seismic requirements.
The North Anna site has both “rock” and “soil” characteristics. The parts of the North Anna plant meeting the “rock” definition must be able to withstand at least ground motion of 0.12g. The parts of the plant meeting the “soil” definition must be able to withstand at least 0.18g.
What level of earthquake is the plant design to?
Is there a generic level that US plants are designed to or does it vary from plant to plant?
Good to know nothing happend to power plants, such a shame about the Washington Monument though.
I wonder how many oil, coal, and chemical facilties were “obliged” to take this post-quake evaluation and inspection routine.
In lieu this recent East Coast quake that had media hearts a-flutter that it’d pop nuclear plants like overinflated balloons, it’s notable that the media has very effectively squashed that Diablo Canyon, in 1989 ate a 7.9 earthquake hitting San Fran. It did knock the plant off, because of vibration, but by 8 AM the next morning the plant was generating at power, and crews were resetting power lines. NONE of the coal or gas generators, was able to start up for weeks because of the damage in the region. Why the omission, fair and accurate mainstream media?
James Greenidge
Queens NY