Radioactive Leak Linked To Design Flaw At Yankee Plant
06/22/10 5:50PM By Susan Keese
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(Host) Entergy Vermont Yankee has released its investigation into the cause of radioactive leaks discovered this winter at the plant.
The report traces the problem to the plant's original construction in 1972 - and also to ineffective monitoring by Entergy.
VPR's Susan Keese has more.
(Keese) Entergy says the leak's direct cause was debris from the plant's construction in the early seventies - a piece of insulation, which clogged an underground drain.
A gap in the concrete casing around a backup drainpipe installed in 1978 allowed water from the flooded pipe tunnel to leak into the soil.
But according to plant manager Chris Wamser, the ‘root cause' goes back to ‘inadequate housekeeping practices' and poor installation of a pipe tunnel that should have been air tight.
Wamser says a second root cause is poor monitoring and inspection.
(Wamser) "Other items or technologies such as remote cameras...or some type of monitor on the sump pump could have been tools that would have given our operators and engineers indications as to whether there was any degraded condition in that tunnel or not. And we did not have either of those in place at the time."
(Keese) The report also blames a lack of commitment by the plant to introducing groundwater protection guidelines. The guidelines were set several years ago by the nuclear energy institute-the industry's policy organization - after tritium leaks were discovered at other plants.
Many of the guidelines are voluntary. And while the plant adopted some - including the test wells that revealed the leak - a number of preventive maintenance initiatives were left undone.
Wamser apologized for the concern the leaks have caused.
(Wamser) "We take pride in what we do here everyday and we take our responsibility to protect the health and safety of the public seriously. We are committed to improving our performance in this area going forward."
(Keese) Plant officials say 240 cubic feet of contaminated soil has been removed. One hundred thirty thousand gallons of groundwater have been removed so far.
Another 170,000 gallons at least will be pumped, cleaned and reused in the nuclear reactor. The plant has identified more than a hundred pipelines that merit closer monitoring for leaks. Spokesmen say five will need to be rerouted or redesigned.
Entergy has spent about $10 million addressing the leak. Spokesmen say much more will be invested in improvements indicated by the report.
Despite the Legislature's recent ‘no' vote on the plant's bid for a 20 year license extension, plant officials say they hope to convince Vermont that the extension is in the state's best interest.
Nuclear engineer Arne Gundersen is a member of the state's nuclear oversight panel. He says the report is accurate as far as it goes.
But he notes that the leaks were likely occurring a few years ago when Entergy was apologizing for its cooling tower collapse. And he wonders what potential problems the report left out.
For VPR News, I'm Susan Keese.