Nuclear Regulatory Commission officials want explanations about why and how part of a Vermont Yankee cooling tower collapsed earlier this week.
Plant executives say they’re trying to answer questions themselves.
But they say the plant is safe while it operates at reduced power.
VPR’s Ross Sneyd has more.
Nuclear power opponents are distributed emails with photographs that they say show the damage at the Vernon plant.
The pictures show a 50-foot tall section of wall that’s made of large plastic and fiberglass louvers. It’s collapsed onto a fence and water gushes from a ruptured pipe high up in the structure.
(Sheehan) "The photos are pretty dramatic. There’s no question about that."
Neal Sheehan of the Nuclear Regulatory Commission says the photos show the complete collapse of what’s known as a "cell" in one of the two cooling towers at Vermont Yankee.
(Sheehan) "They certainly need to come up with more answers about why this occurred. But it doesn’t call into question the safe operation of the reactor day to day."
Vermont Yankee doesn’t have the huge, conical-shaped cooling towers that are such a familiar symbol of the nuclear industry.
Instead, Yankee has what are known as "mechanical draft, forced air" towers.
Water that’s drawn from the Connecticut River flows over condensers to help cool a separate water system that generates the plant’s electricity.
The heated river water then flows through pipes supported by a wooden structure, gradually cooling it before it’s returned to the Connecticut.
For reasons that are not yet clear, part of that wooden structure in one of the cells collapsed, several days after unusual noise was first detected inside the unit.
Vermont Public Service Commissioner David O’Brien downplays the photos. Given the relatively weak material that they’re made of, he says, it’s understandable why the cell would collapse if there’s a problem elsewhere in the tower.
(O’Brien) "Once whatever it was gave way and created a problem with the water main going through, you could pretty much be assured the exterior wall would give way."
The N.R.C. says the collapse isn’t unprecedented. Many fossil fuel plants have the same structures and some of them have had failures in the past. But it’s considered unusual.
The Vermont Public Interest Research Group calls the failure "breathtaking."
James Moore works on energy issues for V-PIRG.
(Moore) "This incident calls into question all of the claims that Entergy Nuclear has made about the plant’s clean bill of health and that it’s operating like new."
Entergy spokesman Rob Williams says the company is investigating what caused the collapse. He says until that’s done, any speculation about the plant’s long-term life is premature.
For VPR News, I’m Ross Sneyd.