ML20086H604

AO 75-51:on 750819,core Spray 3A Full Flow Test Valve MO-3-14-26A Failed to Close.Caused by Defective Torque Switch & Broken Wire to Motor Brake.Broken Wire Repaired & Torque Switch Replaced

ML20086H604
Person / Time
Site:	Peach Bottom
Issue date:	08/29/1975
From:	Meyer R PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Boyd R Office of Nuclear Reactor Regulation
Shared Package
ML20086H608	List: ML20086H604 ML20086H609
References
AO-75-51, NUDOCS 8401180152
Download: ML20086H604 (2)

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PHILADELPHIA ELECTRIC COMPANY /W 2301 MARKET STREET ,,,

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PHILADELPHIA. PA 19101  ; .d.'

saisi e414ooo 6 Ok ', i August 29, 1975 Ng(. '

Mr. Roger S. Boyd, Acting Director Division of Reactor Licensing Office of Nuclear Reactor Regulations United States Nucicar Regulatory Commission Washington, D.C. 20555

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, Region 1, Office of Inspection and Enforcement, United States Nuclear Regulatory Comission on August 20, 1975 Wri tten notification was made to Mr. James P. O'Reilly, Office of Inspection and Enforcement,

, Region i United States Nuclear Regulatory Commission on August 20, 1975 In accordance wi th Section 6.7.2.A of th'c Technical Speci fi-cations, Appendix A of DPR-56 for Unit 3 Peach Bottom Atomic Power S ta ti on, the following report is being submitted to the Directorate of Reactor Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-56 Technical Specification

Reference:

4.5.A.1.c Report No.: 50-278-75-51 Report Date: August 29, 1975 Occurrence Date: August 19, 1975 Faci li ty: Peach Bottom Atomic Power Station R.D. #1, Del ta, Pennsylvania 17314 Identi fication of Occurrence:

3A Core Spray. Full Flow Test Valve, M0-3-14-26A, failed to close.

Conditions Prior to Occurrence:

Unit 3 was operating at 55.2% power.

Description of Occurrence:

During the performance of surveillance testing, M0-3-14-26A failed to close from the wide open posi tion during operation of both core spray "A" loop pumps at rated flow. During single and zero pump ,

l operation the valve closed satisfactorily.

05000 8 g S PDR COPY SENT REGION Yw 3Cl9

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• Mr. Rogar S. Boyd g

• August 29, 1975 50-278-75-51 Page 2 Designation of Apparent Cause of Occurrence:

Defective torque switch and a broken wire to motor brake.

These resulted in overloading the motor such that it would not operate the valve.

Analysis of Occurrence:

Because the valve is only opened for a short period of time once a month during survelliance testing, the redundant system was operable, and the operator conducting the test would have been able to stop the pumps, close the valves, and restart the pumps, there is mininal safety significance.

Corrective Action:

The broken wire was repaired and the torque switch was replaced.

Failure Data:

, No previous failures of this type.

Very truly yours,

' & (Yl(( $

Rankin D. Meyer General Superintendent

' Generation Division cc: Mr. James P. O'Reilly, Director, Region 1 Office of Inspection and Enforcement United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 e

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