ML20035F390

Demands That Reactor Remain in Cold Shutdown Until Plant Mgt Can Provide Proof That EDGs at Plant Able to Meet EDGs Safety Function.Plant Currently Shutdown to Deal W/Feedwater Leak

ML20035F390
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	04/08/1993
From:	Daley M NEW ENGLAND COALITION ON NUCLEAR POLLUTION
To:	Martin T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 9304210228
Download: ML20035F390 (2)

Text

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Ne,w England-Coalition on Nuclear Pollution,Inc.

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~ Box 545, Brattleboro, Vermont 05301 Phone (802) 257-0336 April 8, 1993 Thomas T. Martin, Regional Administrator t

U.S.

Nuclear Regulatory Commission--Region I 475 Allendale Road King of Prussia, PA 19406

Dear Mr. Martin:

As you know, Vermont Yankee is-currently shut down to deal with a feedwater leak. We are writing you to demand that the reactor remain in cold shut down until plant management can provide proof that the emergency diesel generators at the Vermont Yankee nuclear power plant are able to meet their safety func-j tion.

In previous letters to you and to Chairman Selin, and in legal briefs filed in a recent intervention, we have shown that i

this plant has a history of problems with its diesel generators,

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and that its attempts to solve these problems with-the plant operating at full power were unsafe and illegal.

Recent informa-tion has compounded our concern.

i According to LER 90-017-01, dated 2-19-93, diesel generator i

"A" was damaged by overload conditions suffered during testing in August through October of 1990.

The "B" unit also suffered under the same testing regime.

Vermont Yankee now believes that one of r

the causes of the repeated failures of the "A"

unit in the summer of 1992 was the damage from this testing.

The overloading resulted from inappropriate actions taken in i

response to an NRC-identified violation indicating that the emergency diesel _ generators had -- for twenty years -

not been tested at loads consistent with the maximum expected accident load.

The history of this is documented in LER 90-010-00, 01, I

and 02, NRC inspection reports 50-271/9080, and 90-10, and NRC information notice 91-13.

The identification of damage nearly two years after_the originating conditions raises a number of questions which must be immediately answered if Vermont Yankee is going to be allowed to depend on these machines to fulfill the regulatory requirements for adequate on-site emergency backup power systems.

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What other flaws with catastrophic potential might remain en$

undiscovered in both generators as a result of the 1990 overload O '

conditions?

Given the inability of previous testing to identify gn the cylinder flaws, what new testing procedures can be applied to to provide assurance that hidden flaws are revealed?

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2. Why did the LIMITED inspection conducted in October 1990 om fail to identify the " original flaws" (LER 90-017-01) in the

.5" cylinder walls?

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85 2a. Why did all surveillance and maintenance activities

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during the ensuing two and a half years fail to find this problem before it resulted'in gross failure indications?

2b. Was Vermont Yackee's desire not to jeopardize its capacity factor and 2.ts record-setting operations responsible for l

its decision not to undertake more thorough (though time consuming and l

costly) investigations?

2c. How can the public have confidence in Vermont Yankee surveillance practices and NRC oversight to assure operability of' safety systems when these practices failed to identify the damage done to the machines by the overloading?

3. Given the pivotal safety role of the emergency diesel l

generators, why were the defects in the original _ components not j

identified at the time of manufacture, or by over twenty.. years of maintenance?

What other unidentified flaws might exist in the units, or in other plant equipment with equally vital safety

- i functions?

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What other equipment used in normal plant operations and_

for back-up safety. purposes have suffered similar abuses?

Can the NRC provide assurances that potentially dangerous conditions have all been identified and corrected in these instances?

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Vermont Yankee recently canceled plans to do a maj or overhaul of the "B"

generator.

Given thr new evidence contained in the root cause analysis of LER 92-017-01, is it prudent to postpone any service of this machine?

5. Did the NRC act prudently in-allowing continued' operation of. Vermont Yankee in August 1990 after identification of a viola-tion indicating that the emergency diesel generators' ability to 4

handle expected emergency load had never been empirically veri-fled?

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7. What assurances can be made that the current testing regime in fact demonstrates the units' ability to meet expected emergency loads?

In light of this information and the numerous serious questions raised here, the NRC should require Vermont-Yankee to

.j remain shut down until satisfactory answers-are provided.

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'lf-Sincerely [ l -

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g q, Michae J'.

F ley for t e _oard of the New Eng'l a n d Coa lit. ' n _ on Nuclear Pollution 1

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Gov. Howard Dean Leslie Greer, assistant Attorney _ General, Massachusetts I

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