Tritium contamination is near strength of reactor water
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By SUSAN SMALLHEER
Staff Writer - Published: February 7, 2010
VERNON – The highest level of radioactive tritium yet — 2.45 million picocuries per liter – was discovered Saturday in a new groundwater monitoring well at the Vermont Yankee nuclear reactor.
The Department of Health announced the discovery, which was in a well near the building holding the advanced off-gas system.
The department said such high concentrations were an indication that one or more pipes are leaking highly contaminated water into the ground.
Nancy Erickson, communications director for the Department of Health, said the new level is very close to the tritium concentration in reactor water, which is usually measured at 2.9 million picocuries for tritium.
Erickson said the contaminated well is near an excavation that was made to inspect a concrete duct that encases a 2-inch drain pipe.
It is also near two buried pipes that carry reactor process water, she said.
Saturday's measurements were in a groundwater monitoring well, while Friday's measurement of 2.7 million picocuries was in a sump pit inside the advanced off-gas building.
As has been the case since Jan. 7, when Entergy Nuclear disclosed it had a tritium contamination problem, the Department of Health said that while the levels were very high, they didn't currently pose a risk to the public.
"It's not in drinking water so it's not a danger to people," said Erickson. According to the Environmental Protection Agency, the safe level for tritium in drinking water is 20,000 picocuries per liter.
William Irwin, the radiological health chief for the Department of Health, said the high concentrations indicated the contamination was very close to a source, and something that had recently been in the reactor.
He said he was concerned that the pipes carrying these high levels of radioactivity weren't in any kind of tunnel or vault so they could be routinely inspected for leakage.
"It's personally disappointing," said Irwin, who said he believed that the pipes uncovered Saturday were some of the 40 pipes finally listed by Entergy Nuclear last month, after more than a year of saying such pipes didn't exist at Vermont Yankee.
Irwin said the two groundwater wells with the highest contamination, GZ-10 with 2.45 million and GZ-7, with 834,000 picocuries, were about 100 feet from each other.
"The good news is they are very, very close," said Arnie Gundersen, a nuclear engineer who is a consultant to the Vermont Legislature. "They are almost as high as they could go. This is almost raw reactor tritium."
Entergy Nuclear spokesman Robert Williams said he would issue a news release Saturday evening, but it was not received in time for today's paper.
susan.smallheer@rutlandherald.com
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