(Host) Vermont’s largest electric utility says Vermont Yankee must pay for a power outage at the nuclear plant last year. Central Vermont Public Service Corporation wants Yankee to cover the cost of replacement power purchased when a fire knocked the plant off line.
VPR’s John Dillon reports:
(Dillon) When Yankee was sold to the Entergy Corporation, the new owners included a guarantee. Entergy promised to reimburse its customers if the plant shut down because of modifications made to boost power at the plant.
Yankee wants to increase its power output by 20 percent. Last spring, plant operators installed new air cooling equipment needed for the power uprate. Entergy was allowed to start on the work on the project even though it hasn’t yet received federal approval.
Steve Costello at Central Vermont Public Service Corporation says that the new air system started a chain of events that led to the fire on June 18 last year.
(Costello) “What we believed happened is that, in the uprate process, they increased the capacity of their air handling system significantly, vastly improving or speeding up air movement in their air cooling system. And we believe that led to a part in the ductwork being shaken off of it, off the duct, and falling into bus work, or conductor work. And that ultimately started the fire. But more importantly to this case, it shorted the system out and took the plant off line.”
(Dillon) The plant was off line for two and a half weeks. CVPS paid $860,000 for replacement power. The utility has now gone to the Public Service Board to get Yankee to pay up.
(Costello) “The approval of the sale included a consumer protection clause that was intended to protect consumers from any outages caused by activity related to the uprate. And we believe that in this case specifically, that the cause of the outage was related to work being done as part of the uprate.”
(Dillon) The Department of Public Service, which represents ratepayers, seems to agree with CVPS. The state’s nuclear engineer looked into the cause of the outage and wrote a memo last fall that blames the uprate. Engineer William Sherman said, “it is highly likely that power uprate modifications causes this forced outage.”
Sherman pointed out that the new cooling system forced air at a much faster velocity through the duct work – about 45 miles per hour instead of 20 miles per hour. He says this blast of air most likely caused a piece of metal to flap back and forth and then fall off, leading to the electrical short.
Entergy, however, says the uprate work was not to blame. Spokesman Rob Williams says the metal failed because it was old and worn.
(Williams) “We don’t believe that the outage or the fire was related to the uprate. Since it appeared that, due to fatigue, expansion and contraction of that joint over the years, that it would have happened eventually anyway.”
(Dillon) Green Mountain Power also paid about $520,000 for replacement power during the outage. A spokeswoman for the utility says it’s still evaluating its options in the case.
For Vermont Public Radio, I’m John Dillon in Montpelier.