(Reuters) - At least two major New Jersey nuclear power plants are likely to shut on Monday as Hurricane Sandy makes landfall as a Category 1 storm, and more plants could reduce power as the storm triggers precautionary safety measures.
"Sandy, centered over the Atlantic Ocean about 310 miles (505 km) southeast of New York City, was expected to hit near Delaware and south New Jersey in about 12 hours as a Category 1 hurricane with winds of up to 90 miles per hour (144 kph).
The nuclear reactors in Sandy's current path include units at Public Service Enterprise Group Inc's 2,332-megawatt (MW) Salem and 1,161-MW Hope Creek plants in New Jersey, which were likely to bear the brunt of the storm before it moves inland. Those plants combined would account for about 19 percent of the state's total electricity capacity, although New Jersey also draws supplies from the whole Pennsylvania, New Jersey, Maryland (PJM) power region.
PJM is the biggest power grid in the United States serving more than 60 million people in 13 U.S. Mid-Atlantic and Midwest states and the District of Columbia.
Electricity traders said if Sandy continues on her expected path it was likely PSEG would have to shut the Salem and Hope Creek reactors later Monday, but they were mixed on whether the storm's winds would still be strong enough to force the shutdown reactors in Pennsylvania and Maryland.
PSEG spokesman Joe Delmar said the company would take the Salem and Hope Creek reactors offline if wind speeds reach greater than 74 miles per hour (119 kph) onsite for more than 15 minutes or the river water level reaches 100 feet (30 meters). Sandy's maximum winds were at 85 mph (136 kph) earlier on Monday.
The mean river water level was 89 feet (27 metres) and the site grade was about 102 feet (31 metres). The highest river level ever recorded was 97.5 feet (29 metres), he said.
But Sandy was expected to lose some punch as she moves over Pennsylvania and Maryland, crossing near Constellation Nuclear Energy Group's 1,705-MW Calvert Cliffs nuclear plant in Maryland, Exelon Corp's 2,244-MW Peach Bottom, 805-MW Three Mile Island and 2,264-MW Limerick in Pennsylvania, and PPL Corp's 2,450-MW Susquehanna in Pennsylvania.
All U.S. reactors have procedures that require operators to shut the units when hurricane-force winds reach their sites or when floodwaters reach certain levels.
Nuclear power represents about 18 percent of the generating capacity in the U.S. Mid-Atlantic region. One megawatt powers about 1,000 homes.
A few reactors in the area were already shut for refuelling or other maintenance, including Exelon's Oyster Creek in New Jersey, PSEG's Salem 2 in New Jersey, and PPL's Susquehanna in Pennsylvania.
Both Salem Unit 1 and Hope Creek were at full power Monday morning and the refuelling work on Salem Unit 2 was suspended by 6 p.m. EDT Sunday, Delmar said."
