Yankee leak repaired
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By Susan Smallheer STAFF WRITER - Published: June 26, 2009
BRATTLEBORO — Entergy Nuclear said Thursday it had fixed a stubborn leak in its condenser and completed other emergency repairs, which would allow the Vernon reactor to return to full power by today.
The plant had started reducing power on Monday to make the emergency repairs, and had lowered the plant's production to 26 percent for the interim of the repairs.
The repairs were completed at 3 a.m. Thursday, according to plant spokesman Larry Smith.
Smith said that the leak in the condenser, which was leaking about two quarts a minute (30 gallons an hour) of Connecticut River water into the reactor's direct cooling system, was located quickly and fixed. The plant uses 360,000 gallons a minute of water from the Connecticut River to cool the reactor, discharging it back into the river.
He said the leak occurred in one of the four water boxes that make up the condenser, which acts as a giant radiator of sorts in cooling the radioactive steam from the reactor.
Smith said that he didn't know the source of the leak, but he said it wasn't the result of thinning pipes in the condenser, which is made up of 24,000 tubes. Thinning pipes is a usual cause of leaks in condensers due to water chemistry corrosion.
"I don't know what caused the leak," Smith said. The leak was discovered about a month ago.
River water contains more chloride than the purified water used in the reactor cooling system, and it was the presence of chloride that tipped off plant personnel of the leak, he said.
Smith said advance research and planning had narrowed the possible location of the leak, noting that the leak was found within an hour and a half of reducing power.
The condenser, which is slated to be replaced if Entergy Nuclear gets federal and state approval to keep operating beyond its original license deadline of 2012, is estimated to cost about $100 million. It is original equipment in the reactor, which started operating in 1972.
Smith said the condenser had a leak last year, which plant personnel had been unable to locate until the plant shut down in October for its regular refueling and maintenance outage. "We did find it during the outage and repaired it," he said.
susan.smallheer@rutlandherald.com
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