The US Nuclear Regulatory Commission (NRC) has begun a week-long special inspection at the Columbia Generating Station, near Richland, Washington. NRC inspectors are reviewing a problem with a piece of equipment used to cool a room housing important emergency electrical equipment.

"During a recent inspection, the licensee discovered a large heat exchanger that provides cool air for a room housing electrical circuit breakers and safety-related batteries had not been properly maintained, reducing its capability," NRC said in a statement.

The regulator noted however that in the event of an emergency, a redundant system could have provided cooling. It said that workers have already taken corrective action to address maintenance issues.

"The purpose of this special inspection is to better understand the sequence of events that contributed to the maintenance problem and review the licensee’s corrective actions to ensure this cooling system will perform as intended," said Region IV Administrator Arthur T. Howell.

An inspection report documenting the team’s findings will be publicly available within 45 days of the end of the inspection.

Photo: Columbia Generating Station (Source: NRC)