Entergy’s Palisades nuclear power plant in Covert shut down on Friday after the system that cools the reactor began leaking water at around 15 gallons per minute.
 
The Herald Palladium reports:

The plant was shut down shortly before 3 p.m. because the leak exceeded the plant’s technical specifications, spokesman Mark Savage said. The plant filed a notification of an “unusual event” with the federal Nuclear Regulatory Commission.

The likely cause of the problem is a leak on a valve in the primary cooling system, but that won’t be known for certain until workers can get in and do a thorough evaluation, Savage said.

There is no estimate for when the plant will be back in operation, Savage said Friday afternoon.

An “unusual event” designation is the least serious of four emergency classification levels used by the NRC. It means that plant workers are aware of the situation and are working to resolve it. In this case, there is no effect on the public and no release of any radioactive material into the environment. The water that was leaking is contained in the containment building’s sump system and will be treated on site.

The NRC currently lists Palisades as operating at two percent power.

Palisades’ 798-megawatt reactor began operation in 1971, and through a license extension granted by NRC, may operate until 2031.

Environmental groups warn that NRC has loosened safety rules in order to allow the aging Palisades plant to continue operation.