62 cracks found at Vt. Yankee

62 cracks found at Vt. Yankee

Reformer Staff

BRATTLEBORO — There are 62 cracks in an important piece of equipment at Vermont Yankee, but plant officials and federal regulators say that’s not a problem.

The hairline, surface cracks in the plant’s steam dryer were found this month during a routine shutdown. Entergy Nuclear, owners of the plant, and the Nuclear Regulatory Commission said the cracks pose no safety threat.

The cracks are not structurally significant and they are probably from the plant’s early years of operation, according to Neil Sheehan, spokesman for the NRC. They “appear to be old,” he said.

However, nuclear watchdogs say the cracks are one more reason why the NRC should put the brakes on Entergy’s plans to boost power at the plant to 120 percent. A so-called “uprate” at Vermont Yankee is pending final review by the NRC.

In other nuclear plants that have been uprated, cracks in the steam dryer have been a persistent concern.

Vermont’s congressional delegation has identified the cracks as a problem, too. The state’s senators and sole representative wrote to the NRC on Thursday, urging the agency to evaluate the steam dryer issue before approving the uprate.

The Vernon reactor has been off line for re-fueling since Oct. 22. During the outage, plant engineers looked at the reactor and the steam dryer, located at the top of the reactor. They found 42 cracks, ranging from 1 inch to 5 inches in length, said Rob Williams, spokesman for the plant.

The other 16 cracks were discovered in March 2004, during the last refueling outage.

The cracks could have been on the steam dryer more than 20 years, but they’ve only been discovered now because engineers are using cameras with higher resolutions than ever before.

The images show the cracks have been reviewed by Entergy officials, as well as the NRC and General Electric.

Vermont Yankee is a boiling water reactor that started running in 1972.

When the reactor heats up, it produces steam which, eventually, produces power. Before the steam hits the plant’s turbines, it passes through the steam dryer, where any traces of water are removed.

The Quad Cities Generating Station in Illinois, also a boiling water reactor that went on line in 1972, was granted a 17.5 percent uprate by the NRC in 2002.

Since then, the steam dryer has failed twice because of cracking. In one instance, a piece of the dryer broke off and damaged other components of the reactor. The plant has been shut down a number of times to try to fix the problem.

The NRC is scrutinizing the steam dryer issue at Vermont Yankee as a result. This fall, it told plant officials that in order to have their uprate approved, they’d have to adhere to more stringent maintenance of the steam dryer. Entergy agreed to the condition.

Ray Shadis, technical advisor for the nuclear watchdog New England Coalition, said the added oversight amounts to “an experiment on the banks of the Connecticut River.”

“They are now making the assertion that because these are surface cracks, they will go no further.”

And particularly in light of a 20 percent boost in power output at the plant, Shadis said, “that’s preposterous.”

Entergy officials have until the end of the month to prove that the cracks won’t be exacerbated by an uprate, said Sheehan, of the NRC.

Plant engineers will evaluate the steam dryer and submit a report to the NRC for review. The NRC will not investigate the issue itself.

However, in a letter to the NRC chairman, Sens. Patrick Leahy, D-Vt., and Jim Jeffords, I-Vt., and Rep. Bernard Sanders, I-Vt., indicated that’s what they’d like the agency to do.

“We request that the condition of the steam dryer be fully evaluated, using the techniques of the most recent inspection and any other appropriate means,” the letter states. “… it is essential that our constituents receive needed information about whether the plant’s steam dryer will be able to withstand boosted power conditions and operate safely and reliably.”

While Vermont Yankee was shut down, plant officials refueled the reactor with a fuel specifically designed for the plant’s “uprated” production, according to Williams, plant spokesman. During last year’s outage, plant officials installed the same fuel.

Entergy has reportedly done other work at the plant in preparation for the power boost, but Williams could not say how much officials have spent in anticipation of an uprate.

The uprate has been approved by the state’s Public Service Board, a quasi-judicial panel that handles all matters related to utilities. The board’s approval is not final, however; members are still deliberating whether they want an independent safety assessment of the plant done first.

The NRC is the last, major agency that must endorse the uprate. This month, it all but granted tentative approval. It’s “draft” evaluation will bear public review on Nov. 15 and 16, when an agency panel hosts hearings at the Quality Inn in Brattleboro.

NRC officials have said they will issue a final evaluation of the uprate early next year.

Kristi Ceccarossi can be reached at kceccarossi@reformer.com.