COVERT, MI — A minor leak of cooling water that forced Palisades nuclear plant near South Haven to be removed from service on Sunday is from a different part of the plant than the leak that forced the plant to be shut down for a month earlier this summer.

Mark Savage, Palisades spokesman, said the leak that caused Sunday's shut down was from the primary coolant system in the containment building and no radioactive material was released into the environment.

A reading showed that 0.3 gallons of water was leaking per minute. Savage said the amount of water that leaked was a very small amount and the shutdown was a conservative measure.

The water would go through the reactor, circulate through the system, pick up heat and carry heat for the steam-making process, Savage said.

Entergy, the Louisiana-based company that owns the plant, voluntarily shut down the plant on June 12 because of a leaking cooling tank. The tank held borated water that would be used to cool the reactor in a plant emergency or when the reactor fuel needed to be replaced.

The plant was shut down after the leak reached more than 31 gallons in a day and was returned to service July 11 after repairs were made.

Palisades has been under increased scrutiny because of a variety of problems over the past year. The Nuclear Regulatory Commission downgraded the plant in February and classified Palisades as one of the four worst performing nuclear plants in the United States.

An independent review of Palisades nuclear power plant conducted by Conger & Elsea Inc. earlier this year said investigators found "examples of a lack of accountability at all levels at the plant."

Savage said the plant doesn't release timetables for when the repairs are expected to be completed.

Contact Anthony Smigiel at asmigiel@mlive.com.