ML20083Q031

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Ro:Problem W/Electromatic Relief Valve Discovered During Annual Insp Outage.Info Re Leakage Detailed in . Weld Sealed Instead of Stitch Welded.Valve Fully Operable
ML20083Q031
Person / Time
Site: Nine Mile Point, Oyster Creek, 05000000
Issue date: 08/16/1972
From: Perkins T
NIAGARA MOHAWK POWER CORP.
To: Skovholt D
US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20083Q029 List:
References
NUDOCS 8302220577
Download: ML20083Q031 (1)


Text

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NI AGARA MOHAWK POWER CORPORATION NI AGAR A r! MOHAWK v

Nine Mile Point Nuclear Station P

O. Box 32 Lyccming, New York 13093 August 16, 1972 Mr. Donald J. Skovholt Assistant Director for Reactor Operations Division of Reactor Licensing Laited States Atomic linergy Commission Washington, D. C.

20545

Dear Mr. Skovholt:

Re:

Provisiona, Gperating License DPR-17 Docket No.

50-220 During the annual inspection outage of Nine Mile Point Nuclear Station, Unit #1 this past spring, a problem with the electromatic relief va;ve was discovered and a letter dated June 2, 1972, forwarded to your off Ce.

In this letter a repair to all six valves w as outlined which would improve the dependability of valve operation.

In effect, the repair was to ren.ove the locking screw and lock retainer plate and in their place cut four 1/4 ' V grooves, 1" long in tae joint between the 2 ' 'M.

disc ret ainer and t ne valve body insert and stitch weld them to;;cther.

4. M >y..,

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,See enclosec drawin;;).

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Elect romatie valve #112 o.. which the disc retainer had backed

% f'..' ;,-i w

v c ut and was found in the bottom of the valve body had sustainec damage Age:S

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to the disc retainer threads and valve body thr7 ads.

A new disc retainer

$?,, d % :

$' 1 %' "

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was purchased, inst alled and stitch welded along the valve body disc re-tainer j oint.

No.s e ve r, the testing of this valve following naintenance reveal ed 1. at ;eak age was developed past de disc retainer into Charber A from Q..mber C T... s would be the result o f damage to the valve body threads.

!: was then deemed accessary to seal weld instead of stitch weld the entire joint between the disc retainer and the valve body to insure no leakage end depencaole ope rat i on of the valve.

Subsequent testing showed the valve ai;s

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o pe rab l e.

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'*0 Ve ry trul y yours,

b' ; " s i

8302220577 730221 PDR ADOCK 05000219 J

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PDR i

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T..I. Perkins

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