Ice Shuts Ft. Calhoun Nuke

Tuesday, January 14, 2014 @ 02:01 PM gHale

A build of ice on one of the gates protecting the intake structure at Fort Calhoun Nuclear Station temporarily shut down the plant, officials with the Omaha Public Power District (OPPD) said Thursday.

The structure has six gates, called sluice gates, in place in the event of a flooding situation, said OPPD spokesman Jeff Hanson. The ice build-up on the one gate was enough to keep it from fully closing. The other five are fully functioning, Hanson said.

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“Even though we don’t have a flood or one in the near forecast, we are required to shutdown until we can resolve the situation,” Hanson said.

Hanson said, under regulations set by the Nuclear Regulatory Commission (NRC), all of the gates must be able to close quickly if a flooding situation arises. The ice build-up on the one gate means it could not close quickly, so the plant had to go offline, Hanson said. “At no time was the public in any danger,” Hanson said.

Workers checking the plant first noticed the ice build-up Wednesday night, OPPD officials said. Operators then began analyzing the situation and at 3:15 a.m. they notified the NRC of the non-emergency condition that would require the plant to shut down.

Hanson said that is the kind of conservative step required in nuclear power operations. The process of safely taking the plant offline began about two hours later and it was offline by 9 a.m. Thursday. Hanson said there were no complications with the shutdown.

Workers have cleared the ice, and are taking steps to manually lower the affected gate. Once they close the gate, the intake structure can operate safely and effectively with only five gates open, Hanson said.

The intake structure houses equipment used to cool and condense steam that has gone through the power turbine. Hanson said the river water never comes near the water that flows through the reactor.

Hanson said there is no timeline as to when the plant will be back online. They will make some repairs to the gate before it can operate.

The temporary shutdown comes about two weeks after the plant restarted after an almost three-year shutdown. The plant was shutdown in 2011 for a routine refueling outage and remained so after historic flooding along the Missouri River, a fire and other concerns. The plant restarted Dec. 26.



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