Energy Northwest reports small silicone oil leak at Columbia Generating Station; heat exchanger replaced

Kelly Elsifagan, speaking for Energy Northwest’s Columbia Generating Station, reported a July event in which a service air compressor heat exchanger failed and ‘‘up to 10 gallons of non hazardous silicone compressor oil ... had likely leaked ... and entered the plant service water system.’’ Staff inspected the plant basin on July 18 and saw no oil sheen; the failed heat exchanger was replaced on July 21 and the replacement passed pressure tests and returned to service by July 22. Energy Northwest notified the National Response Center, the Washington State Department of Ecology, FSEC and the Department of Natural Resources of the potential noncompliance.

The council had no further questions after the update. Kelly Elsifagan said an internal investigation is underway to determine the cause of the heat-exchanger failure and any regulatory follow-up will proceed as needed.

Why it matters: The plant service water system connects to circulating water basins that may discharge to the Columbia River via outfall; staff noted the potential for a regulated discharge pathway and followed state and federal notification protocols.