ML20086H919

AO 75-26:on 750430,excessive Leakage Found on Inboard Isolation Valve 3671C on Penetration N-51C.Caused by Scoring on Seating Surface.Valve Disassembled,Internals Cleaned & Valve Seat Rotated

ML20086H919
Person / Time
Site:	Peach Bottom
Issue date:	05/09/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A Office of Nuclear Reactor Regulation
References
AO-75-26, NUDOCS 8401200348
Download: ML20086H919 (2)

Text

. _ _ - . .

O O .

X :~ ~.m

,;v

/ oc

• e PHILADELPHIA ELECTRIC COMPANY  :-

i

.. .. \ ; r 'n

'$ i'~

• I. \

o0;a.

. ,. ;W L 2301 MARKET STREET 'M' .

d'

(.] l,N * *N' 0" /

PHILADELPHI A. PA.19101 [

ts.,gjfj'[N f/

(215) 041-4 o00

'w~ t OaH id ,

&l #

g May 9, 1975 li . A. Giambusso, Director Division of Reactor Licensing -

Office of Nuclear Reactor Regulations '

United States Nuclear Regulatory Commission Washington, DC 20555

Dear Mr. Giambusso:

~

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, Region 1, Office of Inspection and Enforcement, United States Nuclear Regulatory Commission on May 1, 1975 Written notification was made

to Mr. James P. O'Reilly, Region I, Of fice of Inspection and Enforce-ment, United Stetes Nuclear Regulatory Commission on May 1, 1975 In accordance with Section 6.7.2.A of the Technical Specifications, Arredix ^ ef OPR 56 fcr '!..lt 3 .%s Out Lum ALo.uic Fower nation, the following occurrence is bein'3 submitted to the Directorate of Reactor Licensing as an Abnormal Occurrence.

ReferenEc: License Number DPR-56 Technical Specification

Reference:

4.7.A.2.f Report No.: 50-278-75-26

! Report Date: May 9, 1975 Occurrence Date: April 30, 1975 Facility: Peach Bottom Atomic Power Station l R.D. 1, Delta, Pennsylvania 17314 ,

L Identification of Occu rence: i i

• l

' Excessive leakage of S.V. 3671C on penetration N-51C.  ;

l _ Conditions Prior to Occurrence: '

l' Unit 3 at approximately 100% power. '

Description of Occurrence:

y R

During a routine local leak rate test of the dryweli 02 analyzer (

sample isolation valves, this inboard isolation valve was found to leak ,

in excess of 2000 cc/ min.

8401200348 750509 d PDR ADOCK 05000277 'g )' 3 C' 8 PDR -

d l

Mr. A. Giambusso May 9, 1975 50 - ?78 2t.

(]}; Pa/s)

Designation of Apoarent Cause of Occurrence:

Disassembly of the valve indicated scoring on the seating surface which prevented the valve from seating tightly.

Analysis of Occurrence:

The safety implicption of this occurrence is minimal since the outboard and isolation valve S.V. 3978C was found to operate satisfactorily be leak tight. In addition, the upstream manual isolation valve was closed to preclude any leakage until the valve was repaired and retested.

_ Corrective Action:

This valve was dis-assembled, the internals were cleaned, and the valve seat was re oted. The valve was re-assembled and sub-sequent leak testing of Se valve was successful, i

Failure Data: ,

t Two previous failures of this valve have been reported as A0-50-278-75-ll and al so on 11/9/73 T

Very truly yours, - '--

$ W/

M /J. Cooney /

A s't Gen't Superintendent Generation Division "~

t cc: Mr. J. P. O'Reilly, Director Region 1 Of fice of Inspection and Enforcement -

i United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 l

l

. - - . _ _ _ . ._