Aletho News

Vermont Yankee confirms cracks in cooling pipes

By Susan Smallheer | Rutland Herald | June 23, 2010

BRATTLEBORO — The Nuclear Regulatory Commission confirmed Tuesday evening that a large fiberglass pipe in the recently rebuilt cooling towers at Vermont Yankee nuclear reactor had developed an 18-inch crack and was leaking water.

Another crack developed in a joint in another location along the same pipe, a spokeswoman for the NRC said.

The disclosure of the cracks in the large distribution or header pipe in the east cooling tower comes after Entergy recently completed rebuilding the infrastructure of the two cooling towers over the past three years, after the western tower partially collapsed in August 2007.

Samuel Collins, Region One administrator for the Nuclear Regulatory Commission, and Donald Jackson, another NRC official, comfirmed the cracks in the cooling tower pipe during a public meeting over the annual assessment of the plant’s operation and condition held at Brattleboro Union High School. There are cracks in cell 1-5 and cell 1-8 in the east tower, which is closest to the Connecticut River.

Until the issue was brought up by Raymond Shadis, senior technical advisor to the nuclear watchdog group The New England Coalition, about two hours into the meeting, neither Entergy nor NRC officials had mentioned the problem, which was discovered Thursday by Entergy. The leaks have already undergone a temporary repair, according to Entergy spokesman Larry Smith.

Smith said the two leaks were spilling about 10 gallons a minute, where the large pipe had tapered to 30 inches in diameter. The pipe, which is 36 inches in diameter at it largest spot, carries 90,000 gallons a minute.

The cracks, which were discovered in fiberplastic pipe that is original to the cooling towers, have been reinforced by strapping, he said.

Unlike the cooling tower collapse in 2007, which also involved the header or distribution pipe, which runs along the top of the cooling tower, the structure under the pipe did not collapse, Smith said.

“It was not a structural issue,” he said. In 2007, the cause of the collapse was traced back to rotted wood in the west tower.

Diane Screnci said after the public meeting Entergy will have to determine what caused the pipe to crack in two different locations.

The NRC and Entergy were busy Tuesday discussing Vermont Yankee in a variety of forums. Earlier in the day, Entergy Nuclear held a press conference in Vernon to discuss the status of the radioactive tritium leak at the plant.

Earlier in the day, Entergy Nuclear officials said insulation left behind by construction workers in 1978 had plugged a key drain, and was directly responsible for the radioactive tritium leak at Vermont Yankee nuclear reactor, which so far has cost the company $10 million in cleanup costs.

Michael Colomb, site vice president for Vermont Yankee, told a gathering of press and community leaders Tuesday that progress was being made cleaning up the radioactive contamination at the site, although months of extracting tritium-contaminated groundwater remained.

The company released its own investigation into the radioactive leak Tuesday and said a design flaw, a lack of monitoring and a lack of corporate will were all to blame for the leak.

The plugged drain, which under normal conditions would have allowed leaking radioactive water from other pipes to drain out to a collection system and treatment, instead allowed water to pool in the tunnel and leak out to the environment through a faulty seam. A variety of radioactive isotopes, not just tritium, but strontium-90, cobalt-60, cesium-127 and others, have been found in the soil.

Colomb said the company had identified 111 “piping runs” that contained radioactive isotopes that were either underground, buried or inaccessible. He said Entergy had determined only five of those 111 pipes needed to be replaced with above-ground pipes.

Vermont legislative leaders and the Department of Health have urged Entergy to replace all underground pipes carrying radioactivity with above-ground systems, which are much easier to monitor to avoid a similar radioactive leak.

So far Entergy has removed 240 cubic feet of radioactive soil from an excavation pit surrounding an underground concrete tunnel, which carried drain lines from the advanced off-gas system, plant officials said.

Additionally, about 130,000 gallons of tritium-contaminated groundwater has been pulled out of a new well, and the company says it plans on extracting 300,000 gallons of radioactive water from the ground near the leak.

With many Entergy employees sporting what appeared to be a new “VY4VT” logo, Colomb said the company remained committed to continuing to operate another 20 years beyond 2012, when its original federal operating license expires.

The site vice president said the costs of the cleanup and continuing costs of increased monitoring are proof the company was serious about turning around public opinion and getting legislative approval for continued operation.

The Vermont Senate voted 26-4 against the plant’s license extension, casting serious doubt on the plant’s future.

But company officials said the vote came at a particularly troubled time during the tritium leak, and that it was confident it would prove to Vermonters the company and the reactor could be counted on for 20 more years.

After the session, William Irwin, radiological health chief for the Department of Health, said he wanted the company to come up with a new method of sampling the contaminated groundwater as it reached the Connecticut River.

While sampling has yet to reveal any measurable levels of tritium, Irwin said he believed the highest concentration of tritium contamination wouldn’t reach the river until later this year, probably in the winter.

So far, while the tritium has shown up in about 20 monitoring wells at the plant, it hasn’t showed up in any private drinking water wells.

Irwin said he was pleased with Entergy’s level of activity and dedication to solving the problem, but he said that hadn’t always been the case.

The past couple of years has been marked with problems, he said.

“The work of the past six months needs to be done on a routine basis,” he said. “It’s not what we had prior to this.”

© 2010 Rutland Herald

June 24, 2010 - Posted by aletho | Nuclear Power