ML20086J071

AO 75-5:on 750110,support Flange on Hpsw/Rhr HX Discharge Valve Motor MO-310-89B Failed.Caused by High Valve Vibration Due to Throttling Mode of Valve.Motor Casting Replaced & Valve Returned to Svc

ML20086J071
Person / Time
Site:	Peach Bottom
Issue date:	01/20/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A Office of Nuclear Reactor Regulation
Shared Package
ML20086J073	List: ML20086J071 ML20086J074
References
AO-75-5, NUDOCS 8401230101
Download: ML20086J071 (2)

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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET 3 j c/,7u,,;} -

PHILADELPHIA, PA.19101 ,

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(215) 8414ooo 'N ' , .U q ; .i\Y' s.wNQt' ~hj I J ',-

January 20, 1975 Mr. A. Giambusso Deputy Director of Reactor Projects United States Atomic Energy Commission Directorate of Licensing Washington, D.C. 23545

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, A.E.C. Region 1 Regulatory Operation's Office on January 10, 1975.

Written notification was made to Mr. James P. O'Reilly, Region 1 Regulatory Operations Office on January 10, 1975. In accordance with Section 6.7.2.A of the Technical Specification, Appendix A of DPR-56 for Uni t 3 Peach Bot tom Atomic Power Station, the following report is being submitted to the Directorate of Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-56 Technical Specification Reference 3.5.B Report No.: 50-278-75-5 Report Date: January 20, 1975 Occurrence Date: January 10, 1975 Facility: Peach Bottom Atomic Power Station R.D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

Failure of support flange on IIPSW/RIIR heat exchanger discharge valve motor (50-310-89B).

Conditions Prior to Occurrence:

Reactor shutdown. Primary cooling temperature is approximately 1500F.

y .2 7 f 8401230101 750120  !

PDR ADOCK 05000278 S PDR h-Out'1 TENT REGION

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Mr. A. Giambusso January- 20, 1975 i Page 2 ,

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Description of Occurrence:

During . routine operations of the shutdown cooling mode of the RilR system,'the flange used to bolt the motor to the valve operator gear casing on NO-3-lO-89B failed. The flange is an integral part of the motor end bell casting.

As found, the valve was approximately 1 1/2" open.

Designation of Apparent Causo of Occurrence:

High valve vibration, due to the throttling mode of the valve caused the valve sicm to hammer the packing out of position casting.

and caused a fatigue failure of the motor end bell v

Analysis of Occurrence:

The safety significance of this occurrence is considered minimal, since no cooling capability of the RIIR/IIPSW was lost. The valve failed in the throttled position.

Corrective Action:

TIve mu6vr-casta.ng was replaced and the valve was_re -

turned to normal service.

Failure Data:

Similar difficulties have been reported as Abnormal Occurrences on these reports: AO-50-277-74-53, AO-50-278-74-28, AO-50-278-74-35, and AO-50-278-74-36.

, Very truly yours, k

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M. J. Cooney..

Ass't Gen'l Superintendent Generation Division cc: Mr. J. P. O'Reilly.

Director, Region 1 United States Atomic Energy Commission 631 Park Avenue: *

~ King of Prussia, PA 19406 -

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