Oct 10 - McClatchy-Tribune Business News Formerly Knight Ridder/Tribune Business News - Sean Adkins York Daily Record, Pa.

Around dinner time Saturday evening, an equipment operator at the Peach Bottom Atomic Power Station in the midst of a post-startup test of the plant's second reactor spotted a cracked test line.

The line, used only to test the reactor's cooling safety systems, had been leaking coolant.

The equipment operator immediately contacted the control room.

Within minutes, Peach Bottom officials set in motion a quick series of actions that started with the closing of a valve to stop the leak followed by the plant's declaration of a low-grade emergency, said April Schilpp, a spokeswoman for the power station.

At 6:02 p.m. Saturday, the plant declared an unusual event, the lowest of four emergency levels at a nuclear-powered station that involves an occurrence that could potentially degrade the level of safety at the site.

Almost immediately, the plant began procedures to shut down the power station to repair the test line and run a battery of tests, Schilpp said.

At 5:13 a.m. Sunday, plant officials had safely shut down the plant and exited its unusual event.

At no time during the event was there a threat to public safety or to plant personnel, Schilpp said.

As of Monday morning, the plant's Unit 2 reactor remained off-line.

By that afternoon, plant workers had repaired the leaking test line, Schilpp said.

The plant uses the line to test its safety cooling systems and would not put that pipe into action to cool the reactor in an emergency.

"It was more precautionary than necessary," said Schilpp of the declaration of the unusual event. "It was still the right thing to do."

At the time of the incident, the reactor was coming off of a scheduled refueling outage.

The unit had been supplying electricity to the PJM Interconnection power grid for two hours before the equipment operator discovered the leak, Schilpp said.

All of York County's power flows through the PJM power grid.

Eliot Brenner, director of public affairs for the U.S. Nuclear Regulatory Commission, said the crack in the test line measured about 3 to 4 inches long.

The commission will continue to review the unusual event, he said.

Saturday's low-grade emergency represents the second declaration recorded in nearly three months.

Peach Bottom declared an unusual eventafter a fire that had ignited on the roof of the plant's emergency diesel generator buildings.

Hot exhaust pipes that flow from one of the plant's four diesel generators to the top of the building made contact with roofing material.

As a result, the generator's exhaust gasket, on the roof outside of the building, caught fire.

That fire posed no threat to the public or to the safe operation of the site, plant officials said.

 

POWER TERMS: The U.S. Nuclear Regulatory Commission has FOUR EMERGENCY LEVELS:

--An unusual event signals occurrences have taken place that threaten a potential degradation in the level of safety at a plant.

--Should a utility declare an alert at a plant, events are in process or have occurred that can involve an actual or potential substantial degradation in the level of safety of the plant. Any radioactive release is expected to be limited.

--A site area emergency may be declared should events lead to the actual or likely major failures of plant functions that are needed to protect the public.

--A general emergency involves actual or imminent substantial core damage or melting of reactor fuel with the potential for loss of containment integrity.

Source: The U.S. Nuclear Regulatory Commission