(Host) Federal inspectors are looking closely at Vermont Yankee’s cooling towers after one of the structures collapsed two weeks ago.
The Nuclear Regulatory Commission wants to make sure that the problems that caused the collapse are not affecting one tower that’s used as part of the plant’s safety-related system.
Meanwhile, members of Vermont’s congressional delegation are calling for an additional level of review for Vermont Yankee.
VPR’s John Dillon reports:
(Dillon) The tower structure that failed was used to cool water before it’s returned to the Connecticut River.
So that tower isn’t considered part of the plant’s key safety system. But there are two towers that are safety-related. One could be used in an emergency to cool the reactor. The other is built to withstand earthquakes.
So now inspectors for the Nuclear Regulatory Commission are checking carefully to make sure that those structures are sound.
Vermont nuclear engineer Uldis Vanags was briefed on the NRC’s work.
(Vanags) "The NRC is very interested in that is there anything that caused this collapse of cell number 4 that may be of concern to the safety cells."
(Dillon) Vanags says there probably wasn’t one single cause for the tower accident. He said that for some reason a wooden vertical support beam sank about four inches, and that led to a cascade of problems. He says inspectors are examining whether the wood was rotting or was weakened somehow.
(Vanags) "As they look at this in more and more detail in days coming, maybe they’ll be a better understanding of what the mechanism actually are that caused this. But it’s really looking like it’s not just one smoking gun thing happened. It’s a series of failure modes in the wood structure that caused this."
(Dillon) The Vermont Yankee plant is about 35 years old, and Entergy, the company that owns it, wants to extend the license for another 20 years.
This week, Vermont Congressman Peter Welch introduced legislation that could lead to a more extensive safety review process. Under the bill, the governor could ask the NRC to name a team of inspectors from outside the region to do a complete top to bottom review.
Welch says the issue is public safety and public confidence.
(Welch) "It’s really very simple. How are we going to have process that assures the public that a conclusion reached about safety has independent, objective and fair? And that’s what this legislation is intended to do."
(Dillon) But both the NRC and Vermont Yankee say the legislation is not needed, since the federal agency already does a detailed safety investigation as part of the re-licensing process.
NRC spokesman Neil Sheehan said the commission beefed up its inspections following a study of the Maine Yankee nuclear plant a number of years ago.
(Sheehan) "Therefore we believe if we were to go in and do an independent safety assessment at Vermont Yankee it would really be redundant. It would be covering ground we already cover on an ongoing basis. And furthermore, it would not be a very efficient use of our resources."
(Dillon) Vermont Yankee is producing about 50% power while plant officials repair the tower structure. It may be up to full power next week.
For VPR News, I’m John Dillon in Montpelier.