The US Nuclear Regulatory Commission (NRC) will conduct a special inspection at the Cooper Nuclear Station to review operator errors that affected a safety-related heat removal system.

The plant, located in Brownville, Neb., is operated by the Nebraska Public Power District.

“This special inspection will help us better understand the circumstances that led to the operator error,” said NRC Region IV Administrator Kriss Kennedy. “We need to assess the potential impact on plant safety and the licensee’s corrective actions to ensure that the cause has been effectively naddressed.”

On Feb. 5, 2017, workers discovered that a misalignment of valves may have rendered one of the plant’s residual heat removal systems inoperable for several months. Operators also performed maintenance and testing on a second residual heat removal system during the same period.

As a result, there may have been a period of approximately 72 hours when both systems were unavailable. The residual heat removal system is used to mitigate the effects of a variety of accidents.
Two NRC inspectors will begin their weeklong inspection on Monday, March 13, 2017. A report on the findings will be publicly available within 45 days of the end of the inspection.