NRC: Quake hazards may imperil nuke plantsApr 18 - McClatchy-Tribune Regional News - Christine Legere Cape Cod Times, Hyannis, Mass.
The owner of Pilgrim Nuclear Power Station is being required to spend about $5 million over the next three years to prove the Plymouth plant and the pools where spent fuel rods are stored can stand up to tremors from regional earthquakes. The Nuclear Regulatory Commission had required all nuclear plant owners in the eastern and central United States to submit hazard risk reports based on updated seismic data, by the end of last month. The NRC also required that if seismic activity was found to have increased considerably, plants would have to do further study. Updated seismic data concluded Pilgrim could feel the effects of earthquakes as far away as 400 miles. The previous estimated distance had been 200 miles. "The additional analysis will look at whether existing plant structures and systems could withstand the greater ground movement," said NRC spokesman Neil Sheehan. "They are expected to take at least three years to complete and will be used to determine if upgrades are needed to plant equipment, systems and structures." U.S. Sen. Edward Markey, D-Mass., issued the following statement Thursday, shortly after the power plants' evaluation reports were posted on the NRC's website: "Pilgrim is clearly at higher seismic risk than previously believed, and the NRC should immediately implement mitigation measures in order to keep nearby residents and businesses safe." Daniel Nuta, a structural engineer for Entergy, owner and operator of Pilgrim, said a study of the plant was done in 2010. "Those results give us a high confidence level that old plants will be shown not to be affected by seismic motion," Nuta said. "We will also be doing a smaller, expedited seismic evaluation by the end of this year, looking at the most crucial components." Richard Drake, another of Entergy's structural engineers, doesn't expect the further scrutiny to result in the need for any structural beefing up at Pilgrim. "I believe it's just going to be a paper exercise," Drake said. "The new seismic report broadened its look even to Canada, and it picked up a lot of smaller level earthquakes," Drake said. "There are no faults in the area of Pilgrim, so it's just earth shifting and rebounding from glacial receding." Drake said the abundance of rock along the East Coast results in motion being felt for greater distances "but it doesn't do any destruction."
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