NRC confirms 2005 tritium leak at Vermont Yankee
By Susan Smallheer | Rutland Herald | February 23, 2010
The Nuclear Regulatory Commission confirmed Monday that a whistleblower told the truth last week when he told a member of the Vermont Legislative Oversight Panel there was an earlier radioactive leak of tritium at the Vermont Yankee plant in the same area that is the focus of the current leak.
The confirmation by Donald Jackson, branch chief of reactor projects for NRC’s Region One, again raised the question of why Entergy Nuclear executives repeatedly told Vermont regulators last year there were no underground pipes at the Vernon reactor carrying radionuclides. Jackson said the leak was in 2005, not two years ago, as the whistleblower had originally told Arnie Gundersen, a member of the oversight panel and a consultant to the Vermont Legislature.
Entergy Nuclear spokesman Larry Smith said late Monday he could not discuss the 2005 tritium leak, saying he was still waiting for a letter from Entergy attorneys before talking about the issue.
Entergy Nuclear is excavating the area near the advanced off-gas building, in particular an underground pipe tunnel connected to the building, which is the same area the whistleblower pointed to. The whistleblower said the area in question was in a “high-radiation” area and involved a “radioactive steam leak” which drained into a drain pit.
Jackson said that the exact location of the current leak is still not known, although the advanced off-gas pipe tunnel is of strong interest, so it was impossible to say the two tritium leaks came from the same spot.
Jackson said that the NRC makes no distinction between “underground” and “buried” pipes, something that Entergy has made several times in the past couple of weeks. In Entergy’s words, buried pipes are in direct contact with dirt, while underground pipes are in tunnels or vaults, carrying pipes.
Jackson said the 2005 leak was under investigation, but he said it was a steam leak and the steam contained tritium and potentially other radionuclides.
He said Entergy did list the problem in the advanced off-gas pipe tunnel or vault as one of several corrective actions in 2005.
According to the whistleblower, whom Gundersen said seemed credible and well-informed about the inner workings at Vermont Yankee, the company used a temporary plug to fix the leak, rather than shut down the plant and make a permanent fix.
The whistleblower even went so far as to list the type of material, Furmanite, that Entergy used to temporarily plug the leak.
The whistleblower said that a tent and HEPA filter was set up to catch any radioactive gas during the 2005 case, and that workers used protective clothing.
Gundersen on Monday refused to say whether he had heard again from the whistleblower. Gundersen had turned the information from the whistleblower over to the Department of Public Service and the Vermont Attorney General’s office last week, both of which are investigating the case.
Jackson’s disclosure confirming the whistleblower came during a conference call with reporters, giving an update on the current leak. Neil Sheehan, NRC spokesman, said that Entergy would be issuing a press release about the 2005 leak later in the day.
Entergy Nuclear only started monitoring for tritium leaks in 2007, after an industry-wide suggestion from the NRC. Entergy drilled three monitoring wells on the banks of the Connecticut River, with one revealing elevated levels of tritium in November, which was reconfirmed in January.
Entergy revealed the current tritium leak on Jan. 7, and has been working since then to find the source of the leak.
Entergy, in its daily update about the search for the leak, said it was taking one of its own drinking water wells, which is near the leak’s plume, out of service as a precautionary measure.
That well, the construction office building well, is one of several wells that provide drinking water to the company, and is more than 350 feet deep in bedrock, the company said. The contaminated monitoring wells are relatively shallow, about 35 feet.
Sheehan said that the NRC was able to talk about the whistleblower allegations in 2005 because the whistleblower did not file a report with the NRC. Usually, the NRC won’t discuss whistleblower issues.
Jackson said that it was unknown whether the 2005 tritium leak, which was found in the underground pipe tunnel, had “transmitted” to the ground.
He said that there is a possibility that the tritium-laden steam did escape to the outside environment. “We’re still determining that,” he said. Jackson said the 2005 leak was inside a part of the reactor complex, and should have been maintained in the concrete pipe vault.
Most of the conference call with the reporters dealt with the NRC emphasizing that the current tritium leak currently posed no health risk to Vermonters, since it had not reached any private wells and that while it was reaching the Connecticut River, it was in very low levels, between 200 to 600 picocuries per liter.
While the plant is licensed to release some amounts of radioactivity into the environment, according to Steven Garry, a senior health physicist, they are well within NRC limits.
Garry said that there had been “essentially zero dose” to the general public from the current tritium leak, and he said that any tritiated water that did reach the Connecticut River would be diluted substantially to eliminate any health threat.
Tritium, which is a form of radioactive hydrogen, can cause cancer, but only when ingested in large, concentrated doses. One well at Vermont Yankee has tested for 2.6 million picocuries per liter, although that concentration has dropped to 1.8 million picocuries. Other wells show various other levels of tritium, with the next highest close to 1 million, according to the Vermont Department of Health.
© 2010 Rutland Herald – Source