Dive Brief:
- Indiana Michigan Power’s (IMP) Cook Nuclear Plant leaked about 2,000 gallons of oil into Lake Michigan before the company discovered and repaired the issue, MLive reports.
- In December, plant officials were investigating a declining level trend on a Unit 2 main turbine lube oil reservoir when the leak was identified and stopped.
- IMP officials said the leak, calculated at approximately 0.04 gallons per minute, was not detected in the total water discharge flow of 1.5 million gallons per minute.
Dive Insight:
Indiana Michigan Power officials say the oil leak was small enough to go unnoticed for almost two months, and will require no cleanup. A spokesman told mlive.com that the company noted oil levels dropped slightly on Oct. 26, but that at the time it did not raise concern.
The company notified state and local authorities of the leak on Dec. 20.
According to a December notice with the U.S. Nuclear Regulatory Commission, "no visible oil or oil sheen is present on Lake Michigan or the shore line. The leak is currently isolated."
The Cook facility is owned by American Electric Power and operated by IMP.
The turbine lube oil system contains approximately 25,000 gallons of non-radioactive oil. The hot oil runs across tubes in a heat exchanger that is cooled by water from Lake Michigan. Plant officials believe oil leaked into a tube or tubes and was mixed into the cooling water. The leak, calculated at approximately 0.04 gallons per minute, could not be detected in the total water discharge flow of 1.5 million gallons per minute.
