|
|
||
Leak of contaminated water leads to shutdown of North Anna reactor Date published: 10/27/2009
By RUSTY DENNEN One of North Anna Power Station's two nuclear reactors is shut down because of contaminated-water leaks discovered Friday afternoon. Unit 1 was still down yesterday, said Richard Zuercher, spokesman for Dominion power's nuclear operations. "We are making repairs and expect to return to service soon," he said. According to Zuercher and an event report yesterday by the Nuclear Regulatory Commission, there were two issues with Unit 1's cooling system. Around 4:30 p.m. Friday, a pinhole leak was discovered in the reactor purification system. The system recycles some of the water used to cool the reactor core. "Operators isolated the pinhole by redirecting the water into a backup piping system designed for this purpose," Zuercher said. "That was very, very small--almost like a vapor." But then operators discovered a water leak of more than 15 gallons a minute from a heat exchanger on the backup system. They then swapped the water flow back to the line with the pinhole leak and began shutting down Unit 1. The heat exchanger leak exceeded the regulatory limit for radioactive contaminated water, which the NRC deemed--after the fact--to be an unusual event. The Virginia Department of Emergency Management was notified as a result. An unusual event is the lowest of four levels of emergency classification used by the NRC. Approximately 260 gallons collected in a piping system, not on the floor, Zuercher said. "There was no threat to station employees, nor the public," he said. The North Anna plant is on the Louisa County shore of Lake Anna, near Mineral. An unusual event was declared at Dominion's Millstone nuclear plant in Waterford, Conn., in April 2008. In that incident, a coolant leak was discovered at Millstone Unit 2 when it was shut down for scheduled maintenance and refueling. It is a pressurized water reactor like the North Anna units. That leak between the reactor coolant system and a coolant storage tank was captured by the tank, so there was no release of liquid to the environment. Rusty Dennen: 540/374-5431
1. Be respectful. No personal attacks.
|
|
||||||||||||
