List of buried piping released
BRATTLEBORO -- On Sunday, Entergy Vermont Yankee electronically filed a document with the Vermont Public Service Board detailing the extent of buried piping at the nuclear power plant in Vernon.
The list was in response to a recent controversy over whether Yankee executives supplied adequate information about buried piping to the PSB and Nuclear Safety Associates, which was tasked with conducting a reliability assessment of the power plant.
Entergy has applied to the Nuclear Regulatory Commission to extend the operating license of Yankee for another 20 years, from 2012 to 2032. In addition to NRC approval, Entergy must also receive a certificate of public good from the Public Service Board and the OK from the Vermont Legislature.
The list encompasses more than 40 buried or subsurface pipes and systems, which Entergy executives and plant staff had previously said did not exist.
Yankee attributed the shortcoming to a "miscommunication."
According to an affidavit attached to the list, it is a "comprehensive list that completely and accurately identifies all pipes and systems that meet my understanding" of the requirements outlined in the NSA audit.
"Where was that list hiding?" said Clay Turnbull, spokesman for NEC. "How did someone miss that?"
Today, Entergy is meeting with the Vermont Department of Public Service and NSA contractors to review the list.
NEC has asked the PSB to reopen the record in the Yankee CPG proceeding so that the evidence can be examined "in the light of Entergy's false testimony" and new information regarding leaks of radionuclides into the ground water, said Ray Shadis, technical consultant for the coalition.
"New England Coalition questioned Entergy witnesses on buried piping and site contamination, pointedly and repeatedly, during the Public Service Board technical hearings last spring," he said.
Two weeks ago, Yankee revealed a test well on site showed elevated levels of tritium in groundwater. The monitoring well showed levels of tritium ranging between 14,000 and 28,100 picocuries.
The source of the tritium has not yet been determined, but it was during the initial investigation that regulators learned there was in fact buried piping in use at the power plant.
Last week, during a search for the source, Yankee engineers discovered more than 200 gallons of contaminated water in a 40-foot-long pipe trench in the plant's radiation waste building.
The water was found to be contaminated with up to 2 million picocuries per liter of tritium, 13,000 picocuries per liter of cobalt-60 and 2,460 picocuries per liter of zinc-65.
The Environmental Protections Agency's drinking water limit for cobalt-60 is 100 picocuries per liter and for zinc-65 is 300 picocuries per liter.
A spokesman for the Nuclear Regulatory Commission said this is not environmental contamination.
"This was found inside a locked, confined area inside a building used for the storage and treatment of radioactive waste," said Neil Sheehan.
The half-life of cobalt-60 is 5.27 years. The half-life of zinc-65 is 245 days. Half-life refers to the time required for half the nuclei in a sample of a specific isotopic species to undergo radioactive decay.
The concrete piping trench has not been ruled out as a possible source for the tritium found in the monitoring well, according to a statement from Yankee.
A spokesman for Yankee said the plant has several thousand linear feet of buried piping, but was unable to supply an exact number.
Bob Audette can be reached at firstname.lastname@example.org, or at 802-254-2311, ext. 273.
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