Nuclear power station workers repair reactor leak

Pilgrim Nuclear Power Station workers fixed a leak in the nuclear reactor casing that caused a plant shutdown Saturday night. The plant is expected to be fully operational by some time today, spokesman David Tarantino said.

 

The shutdown occurred around 5 p.m. Saturday after workers discovered a leak in the drywell, the steel casing that surrounds the nuclear reactor. In the event of an accident, the drywell would capture radioactive steam leaking from the reactor.

The drywell is typically filled with nitrogen, making it an area too dangerous for workers to enter.

In order to identify and fix Saturday's water leak, plant workers first had to remove the nitrogen from the area, which allowed oxygen to flow through, Tarantino said.

Upon inspection, workers discovered a valve on the reactor water cleanup system had a "packing leak," he said. It's similar to a leaking faucet needing a new washer.

"A packing leak in a valve is not unusual," Tarantino said. "There's no real safety significance here."

It's not unusual for a plant to leak, no matter its age, echoed David Lochbaum, director of the nuclear project for the Union of Concerned Scientists in Washington, D.C. However, he said, there were some discrepancies in the initial report the plant officials provided to the Nuclear Regulatory Commission.

Plant workers reported that the reactor wasn't producing a lot of power during the course of the shutdown, Lochbaum said. But they also reported a big water level drop while shutting down, he said.

If there wasn't much power in the first place, there shouldn't have been a big drop in the level afterward, he said.

"I'm not saying that they were 30 minutes away from meltdown or anything like that," he said. But, "this report didn't quite nail it yet."

Plant owners have 60 days to submit a formal report to the NRC, he said.

Entergy Nuclear Operations, which owns the plant, has applied for a 20-year extension on a 40-year operating license. The license expires in 2012. Last fall, while performing a safety inspection for the license renewal, Nuclear Regulatory Commission inspectors found a potential problem with the drywell.

While inspectors found no evidence of corrosion, water found on the floor below the drywell and a faulty switch led them to call for further inspections, NRC senior inspector Glenn Meyer said in January. Corrosion testing on the drywell is continuing.

The unplanned shutdown Saturday was the first in almost exactly a year, said Neil Sheehan, NRC spokesman.

The plant was shut down on March 13, 2006, due to problems with the system's recombiner.

Pilgrim will again go off line for a month starting the first week in April for planned maintenance.

The month-long shutdown occurs every two years so workers can replace one third of the fuel rods in the reactor core, Tarantino said.

This weekend's outage, along with the planned outage, will not affect power for those in the region.