Entergy’s Palisades nuclear plant near South Haven on Lake Michigan is venting radioactive steam into the environment as part of an unplanned shutdown triggered by an electrical accident.
 
This shutdown, which began Sunday evening, came just five days after the plant restarted from a shutdown that was caused by a leak in the plant’s cooling system.

Nuclear Regulatory Commission spokeswoman Prema Chandrithal said that the current shutdown happened because an object slipped during work on a circuit breaker and caused an arc that took out power for one of two DC electrical systems that power safety valves and other devices.

According to a notice filed with the Nuclear Regulatory Commission, the plant is stable and “controlling temperature using Atmospheric Dump Valves.”

“The steam that would normally go to the generators, that steam is now going into the environment … through the steam stack,” said Chandrithal. “This would have very low levels of tritium.”

Tritium is a radioactive isotope of hydrogen.

The plant is monitoring the levels and will report them to the NRC, Chandrithal said.

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