May 19 - McClatchy-Tribune Regional News - The Keene Sentinel, N.H.



A mishap during Vermont Yankee's refueling outage this week should not affect safety at the nuclear plant, according to plant and U.S. Nuclear Regulatory Commission officials.

During a test of the plant's emergency core cooling system Sunday, the water level inside the reactor vessel was set to a higher level than usual and some water entered a steam line, according to spokesman Laurence M. Smith.

Plant officials are investigating why the water level was set at that level, Smith said this morning.

The cooling system is designed to cool the reactor so the nuclear fuel is not damaged if the plant has to be shut down in an emergency.

 The steam lines, which don't usually contain moisture, will be drained and dried out because excess moisture can damage the plant's turbines, Smith said.

"There were no safety consequences and the incident was not immediately reportable (to the NRC)," Smith wrote in an e-mail. "Still, plant management has taken steps to ensure this is not repeated in future tests."

NRC spokesman Neil A. Sheehan said the steam lines will be heated before the plant is restarted, which should take care of any excess moisture.

The plant has been in its refueling outage for more than three weeks and is set to go back into operation this weekend, Smith said.

During the refueling outage, re-routing of steam trap piping from the plant's advanced off gas system, where a leak of tritium into surrounding soil and groundwater was discovered in January, was completed to avoid a similar type leak.

Removal of soil contaminated by the tritium -- a radioactive form of hydrogen -- is on schedule for completion in the coming weeks, according to Smith.

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