The roaring winds, at times approaching 100 miles per hour, were relentless as Hurricane Sandy pushed the Atlantic Ocean towards the eastern seaboard.
The sheer breadth of the Superstorm, with hurricane-force winds radiating some 250 miles from Sandy’s eye, meant 34 nuclear power plants from North Carolina to Vermont would experience extreme weather. While the winds themselves posed little danger to the primary physical structures at nuclear installations, the storm was bound to send trees crashing into utility lines and transformers, causing station blackouts which, along the coasts, could well be accompanied by flood waters. In the latter cases, Sandy would provide a test of some of the safety improvements ordered by the Nuclear Regulatory Commission in the wake of the triple meltdown at Fukushima Daiichi in 2011.
At particular risk were nuclear plants along the coastlines of New Jersey and New York, directly in the path of the strongest part of the hurricane.
Massive amounts of ocean water were pounded into storm surges sweeping up the Delaware River and other coastal tributaries along the Jersey Shore; or rammed through Long Island Sound and squeezed up the Hudson River. The combination of storm surge and wind would trigger the declaration of an “alert” at the Oyster Creek on Barnegat Bay, and a forced atmospheric steam vent at the nearby Salem 1nuclear plant along the Delaware River in New Jersey. In New York, the twin Indian Point plants rode out floods along the Hudson River, but Indian Point 3 and Nine Mile Point 2, upstate near Syracuse, were shut down by malfunctions caused by hurricane force winds.
In the view of the NRC, the plants all functioned as designed, even if the weather was unpredictable and some problems were not expected. Eleven northeastern nuclear plants in the direct path of Sandy – including all four in New Jersey – were placed on a special alert status several days before the storm struck that featured additional federal monitors and plans to shut down if the winds or waves exceeded pre-determined storm limits.
That special watch list included Calvert Cliffs in Lusby, Md.; Peach Bottom, in Delta, Pa.; Three Mile Island 1, in Middletown, Pa.; Susquehanna, in Salem Township, Pa.; and Millstone, in Waterford, Conn. None of these were as hard hit as the plants in New Jersey and New York. Millstone 3 and Susquehanna 2 reduced power to 75 percent to accommodate strained regional power grids. But the others operated throughout the storm at 100 percent power.
New Jersey was a different case. As the Superstorm approached, plant officials tested their backup generators and topped off their diesel generator tanks in case they were cut off from the grid and had to rely on their own power to keep reactors and spent fuel pools cooled.
At high tide the Delaware River running past Artificial Island, home to PSE&G’s Salem 1&2, and Hope Creek nuclear power plants, has a normal depth of 89 feet. Salem 1 and Hope Creek were running at full power, while Salem 2 and Oyster Creek were shut for refueling and maintenance. Joe Delmar, spokesman for PSEG Nuclear, said refueling operations were suspended Sunday at 6 PM and unnecessary workers had been sent home.
Under NRC guidelines, Salem and Hope Creek had to shut down if there were sustained winds of 74 miles per hour or the river reached 99 feet in depth. The plants’ “design basis” states the sea wall would repel water up to 120 feet, a level only anticipated with a Category 4 hurricane.
But Delmar said the storm pushed water levels in the Delaware River Monday night to 98 feet, and “the winds created additional waves approximately 12 feet high.”