Virginia nuclear plant shaken twice as hard as design capacity during record 5.8 quake

Monday, September 12, 2011 by: Ethan A. Huff, staff writer
Tags: earthquake, nuclear power plant, health news

(NaturalNews) The highly unusual 5.8 magnitude earthquake that hit the East Coast near the small town of Mineral, Va., on August 23, 2011, is the largest to have occurred east of the Rocky Mountains since 1897, when an earthquake of similar magnitude struck in western Virginia. And reports now say that the recent quake was responsible for causing, for the first time ever, a US nuclear facility to be shaken beyond its design capacity -- and it was shaken about twice as hard as its design limits intended.

The North Anna nuclear plant, which is located in Louisa County, Va., just a few miles from the quake's epicenter, was designed to withstand 0.12 g (peak ground force acceleration), a unit of gravity that measures shaking impact on buildings. But preliminary data released by the US Geological Survey, which will later be compiled in a complete report to be released in mid-October, shows that the plant actually withstood peak acceleration of about 0.26 g.

"The implications of exceedance could be disastrous," said Majid Manzari, an engineer at George Washington University (GWU) who studies earthquakes and their impact, to Reuters. "I would say these studies have to be done as soon as possible."

The studies Manzari speaks of involve reevaluating the safety of the 104 US nuclear facilities, many of which are dangerously antiquated and in need of major upgrades and repairs. The US Nuclear Regulatory Commission (NRC) says that later in the year it plans to issue new requirements that nuclear plants update their risk analyses, but these could take up to two years to complete.

Officials say the North Anna plant was not damaged by the recent quake, as it allegedly safely shut down as intended upon reaching its shaking threshold. However, more recent reports indicate that the plant did not shut down because of a loss of outside power as was initially stated, but because of unidentified problems "inside the cores" that are still being investigated (http://www.reuters.com/article/2011/09/09/ut...).

Sources for this story include:

http://www.insurancejournal.com/?p=214046