"I was concerned, but I didn't think [Oyster Creek] was going to be Fukushima revisited," Lochbaum said.
The lesson that has yet to be learned, he said, is that when plants develop contingency plans based on weather history, they need to incorporate a generous cushion for plant safety.
Of the 34 nuclear plants in Sandy's path from South Carolina to Vermont, 24 continued to operate, reported the Nuclear Energy Institute, a trade group.
Seven of the 10 others, including Oyster Creek, had already been shut down for routine maintenance.
Two reactors in New York and one in Salem County, N.J., were shut down as a result of the storm.
"Careful planning . . . paid off at all of the facilities, which were prepared to take the steps necessary to maintain safety against high winds, record flooding, and disturbances on the regional electric grid," said a statement from the trade group.
At 8:45 p.m. Monday, the U.S. Nuclear Regulatory Commission declared an "alert" at the Oyster Creek plant when water levels in the intake canal rose above six feet.
Even though the plant is shut, water still needs to be pumped to cool spent fuel.
At 6.5 feet, pump operations could be affected, but the problem was minimized because of the shutdown, NRC spokesman Neil Sheehan said. The water reached a peak of 7.4 feet at 12:45 a.m. Tuesday. It had receded to 5.7 feet by 2:15 p.m.
The facility also had to use its diesel-operated generator when power to the plant failed. Power had been partially restored by midafternoon Tuesday. Throughout, the plant remained on "safe" status.
Operators at Salem Unit 1 in Lower Alloways Creek Township in Salem County manually shut the reactor down at 1:10 a.m. Tuesday as a result of circulating pumps being affected by the high river level and debris, the NRC said in a statement.
The Hope reactor at the same site continued to run. The third reactor, Salem Unit 2, had been shut for previously scheduled repairs.
The two Limerick nuclear reactors in Montgomery County reduced power to 50 percent and 22 percent at the request of the regional electrical-grid operator, according to the NEI trade group.
Contact Jane M. Von Bergen at firstname.lastname@example.org, @JaneVonBergen on Twitter, or 215-854-2769. Read her workplace blog at www.philly.com/jobbing