A week after one of two recirculation pumps failed at the Vermont Yankee nuclear power plant in Vernon, Vt., the problem has been fixed and the plant is operating at nearly 100 percent, a spokesman said.
The recirculation pump, which moves boiling water through the reactor to generate steam that gets turned into electricity, failed Sept. 25 due to an electrical issue with the motor generators that operate the pumps, according to Laurence M. Smith, a spokesman for Entergy Corp. of Louisiana, which owns Vermont Yankee.
The pump’s “only function is to make power,” Smith said. “It’s not a safety system; it just makes electricity.”
Smith said the motor generators that control the pumps are large and difficult to access.
“These are specialized components,” he said. “It’s a huge unit to disassemble and get at; you can walk inside one of them.”
Smith said no cooling pumps, which push cooling waters past the reactor to maintain proper temperatures, were compromised at any time.
The plant has been in “single-loop” operation, which allows it to remain online while using one recirculation pump, since the issue was identified, said Neil A. Sheehan, a public affairs officer for the federal Nuclear Regulatory Commission.
Vermont Yankee operated at between 44 and 47 percent power throughout the week, Smith said, but was back up to about 95 percent after the problem was fixed Saturday morning and the recirculation pump was brought back online.
The plant won’t be brought up to 100 percent because of its upcoming refueling outage, scheduled to begin Saturday and last about 30 days, Smith said. That event has not been affected by the pump malfunction, he said.
Smith said while issues with recirculation pumps are fairly common, he couldn’t remember the last time Vermont Yankee had a similar problem.
Sheehan said NRC officials based at Vermont Yankee would continue to monitor the situation.
© 2011 The Keene Sentinel
Distributed by MCT Information Services