THE 5.9-MAGNITUDE earthquake that struck the US state of Virginia yesterday has raised concerns about the safety of nuclear reactors in the country.

The earthquake, which was the largest to hit the US east coast in 67 years, struck less than 24 kilometres from the two-reactor North Anna power plant, Reuters reports.

Power at the plant, operated by Dominion Resources Inc, was automatically cut when the earthquake struck. A spokesperson for the operator said that the plant sustained no “major” damage, however he said that three diesel generators were required to kick in to keep the reactor cool. A fourth diesel generator did not work.

The company said that both units are now operating at full capacity and that they are continuing to monitor the situation, reports the Washington Post.

The earthquake also caused 12 other stations, from North Carolina to Michigan, to declare “unusual events” – the lowest level emergency designated by the US Nuclear Regulatory Commission – reports the San Francisco Chronicle.

Meanwhile, the Washington Monument has been closed to visitors “indefinitely” after engineers found cracks at the top of the structure, reports Business Insider.

The damage was very likely caused by the earthquake, according to a National Parks Service spokesperson. Further examinations will now take place on the 91,00 ton monument.

News of the earthquake spread quickly on Twitter – the official account tweeted: “And, we hit about 5,500 Tweets per second (TPS). For context, this TPS is more than Osama Bin Laden’s death & on par w/ the Japanese quake”.

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