Energy Northwest's Columbia Generating Station temporarily shut down Saturday, starting a planned biennial refueling outage a few days early because of weather conditions.
Station operators started powering the reactor down Friday night following a request from the Bonneville Power Administration. Bonneville made the request to Energy Northwest on Wednesday because weather conditions could produce high water flows through the federal hydroelectric dam system.
The station was scheduled to power down Wednesday for its biennial refueling outage.
During the outage, workers will add new nuclear fuel, conduct maintenance and replace the plant's main condenser -- the largest scope project ever undertaken in the 26-year history of the plant, a news release said.
The condenser converts steam back to water for re-use in the reactor. Replacing it will cost $113 million and require 350 workers. The new condenser will provide up to an additional 12 megawatts of power generation.