ML20086K432

AO 75-12:on 750205,reactor Water Cleanup Sys Pump Suction Inner Isolation Valve Failed to Close.Caused Unknown.Final Investigation of Failure Will Be Performed When Reactor Shut Down & Drywell Accessible

ML20086K432
Person / Time
Site:	Peach Bottom
Issue date:	02/15/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A Office of Nuclear Reactor Regulation
Shared Package
ML20086K436	List: ML20086K432 ML20086K443
References
AO-75-12, NUDOCS 8401270098
Download: ML20086K432 (2)

Text

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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET PHILADELPHIA, PA.19101 1215) 841-4 0o0 x

February 15, 1975 4/

'3Ct . N Mr. A. Giambusso 8 h Director fj  : rP C1

. h,>{'$ DI Division of Reactor Regulations .-

United States Nuclear Regulatory Commission 4, ,4, g ,9/

Washington, DC 20555 N A, v /

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, Office of Inspection and Enforcement, Region 1, NRC on February 5,1975 l Written notification was made to Mr. James P. O'Reilly, Office of l

Inspection and Enforcement, Region 1, NRC on February 5,1975 In ,

accordance with Section 6.7 2.A of the Technical Specifications, ':

Appendix A of DPR-44 for Unit 2 Peach Bottom Atomic Power Station, the t following report is being submitted to the Directorate of Reactor i Licensing as an Abnormal Occurrence.

Reference:

l License Number DPR-44 j Technical Specification

Reference:

3 7.D '

Report No.: 50-277-75-12 Report Date: February 15, 1975 Occurrence Date: February 5, 1975 Facility: Peach Bottom Atomic Power Station R.D. 1, DeIta, PennsyIvania 17314 Identification of Occurrence:

Failure of Reactor Water Clean-up System Pump Suction Inner Isolation Valve to close.

Conditions Prior to Occurrence:

Plant stabic at approximately 100% power.

Description of Occurrence:

During the performance of a surveillance test which verifies the operability of various PCIS valves, the RWCU Pump Suction Inner Isolation Valve, M0-12-15 failed to close in response to a close signal.

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/M h 8401270098 750215

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Mr A. Giambuss .

Februrry 15, 1975 Paga 2 Designation of Apparent Cause of Occurrence:

Since the valve is located in the drywell which is inaccessible during power operation, the investigation has been limited. This limited investigation indicates possible limitorque operator or motor difficulties.

Actual cause of failure is unknown at this time.

Analysis of Occurrence:

The surveillance test performed verified that the in series outer isolation valve on the RWCUS was operable. This valve would satisfy the isolation function. Safety implications of this failure are therefore minimal.

Corrective Action: I Final investigation of the failure of this valve to close and subsequent repair will be performed when the reactor is shutdown and the drywell is accessible. The outer isolation valve was closed to isolate this penetration. Following receipt of a variance in the Technical Specifications, the outer isolation valve was again opened and the system returned to service. The outer isolation valve is being function-i ally tested daily while the inner valve is inoperable. This will con-tinue until plant shutdown on 2/12/75 Failure Data:

None. '

Very truly yours, M. . Cooney A 't Gen' t Superintendent Generation Division cc: Mr. J. P. O'Reilly, Director Office of Inspection and Enforcement  ;

Region I i U. S. Nuclear Regulatory Commission .;

631 Park Avenue King of Prussia, PA 19406

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