Aletho News

History of Leaks Imperils Reactor License Extension in Vermont

A portion of a cooling tower at the Vermont Yankee reactor collapsed Wednesday, August 22, 2007. A broken 52” pipe was photographed spewing water into the ground, in the latest embarrassment for Yankee owner Entergy Corporation, the nation’s second-largest nuclear utility. – © 2010 Boston Globe

Search continues for radioactive Vermont Yankee leak

By Terri Hallenbeck, Free Press Staff Writer • Saturday, January 23, 2010

MONTPELIER — Crews will start drilling more monitoring wells today at Vermont Yankee as the Vernon nuclear power plant’s owners continue the search for the source of a leak of the radioactive isotope tritium.

The tritium leak was revealed three weeks ago after heightened radioactive levels were found in a monitoring well outside the plant. Tests continued this week to show a range of tritium — from 14,000 to 28,100 picocuries per liter, Vermont Yankee spokesman Rob Williams said. The most recent tests were at 20,900, he said.

The Environmental Protection Agency safety standard for tritium in drinking water is 20,000 picocuries per liter.

More heightened levels — as high as 2 million picocuries — have since been found in a concrete trench on the plant’s campus. No heightened levels of radioactive substances have been found in nearby drinking wells that are monitored.

Other radioactive isotopes — cobalt-60 and zinc-65 — have also been found in the trench, which is a locked and confined building where radioactive waste is stored and treated. Williams said Friday that those were found in the Jan. 13 sampling along with tritium.

Neil Sheehan, Nuclear Regulatory Commission spokesman, said 13,000 picocuries per liter of cobalt-60 and 2,460 picocuries of zinc-45 were found in the standing water in the trench. Those are well above federal drinking-water limits of 100 picocuries for cobalt-60 and 300 picocuries for zinc-65. Officials cautioned that the substances aren’t in the drinking water but are in an enclosed part of the nuclear power plant.

Williams said it’s not a surprise to find those other isotopes, nor does the discovery likely help in the search for the source of the leak.

“That’s the kind of material you’d expect to find in the basement of a building that processes nuclear waste,” Williams said. “What we’re looking for is the source of the tritium.”

The leak — and the fact that Vermont Yankee owner Entergy Corp. had told state officials that pipes that might play a role in the leak didn’t exist — have raised concerns about the plant as its owner seeks permission to continue operation for another 20 years after its license expires in 2012. Friday, Vermont’s three-member congressional delegation wrote a letter to the Nuclear Regulatory Commission calling for an immediate investigation.

“This investigation should not only determine whether there was an attempt by Entergy Vermont Yankee to mislead state officials regarding the plant’s safety and underground piping, but also provide a complete and accurate assessment of the full scope of the contamination at and near the plant as soon as possible,” the delegation said.

Meanwhile, Vermont Yankee has constructed a barrier to seal a connection between the trench and an evaporator tank that could be contributing to the accumulation of tritium-contaminated water in the trench, according to the state Health Department, which started posting online updates on the situation Thursday. The seal appears to have stopped condensation of tritium-contaminated water vapor on the corrugated roof over the concrete trench, according to the Health Department.

Engineers are studying the trench’s structural integrity to see if it is contributing to the leak, according to the Health Department.

Also Friday, the NRC extended Entergy’s deadline for spinning off Vermont Yankee and other Northeast nuclear power plants into a new company. Because Entergy has not won approval from Vermont or New York regulators for the move, the deadline has been extended from Jan. 28 to Aug. 1.

January 31, 2010 - Posted by aletho | Deception, Environmentalism, Nuclear Power