ML20086H085

AO 75-67:on 751021,torus Makeup Supply Isolation Check Valve 276Y Found Leaking in Excess of 2,000 Cc/Minute.Caused by Valve Piston Being Hung Up During Operation.Check Valve Repaired & Local Rate Test Repeated

ML20086H085
Person / Time
Site:	Peach Bottom
Issue date:	10/31/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Boyd R Office of Nuclear Reactor Regulation
Shared Package
ML20086H089	List: ML20086H085 ML20086H090
References
AO-75-67, NUDOCS 8401130415
Download: ML20086H085 (2)

Text

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PHILADELPHIA ELECT 71C COMPANY 2301 MARKET STREET PHILADELPHIA. PA.19101

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October 31, 1975

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y Mr. Roger S. Boyd G

W Acting Director Division of Reactor Licensing Office of Nuclear Reactor Regulations United States Nuclear Regulatory Comission Washington, DC 20555

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, Region I, Office of Inspection and Enforcement, United States Nuclear Regulatory Comission on October 21, 1975 Written notification.was made to Mr. James P. O'Reilly, Region 1, Office of Inspection and Enforcement, United States Nuclear Regulatory Comission on October 21, 1975 In accordance with Section 6 7 2.A of the Technical Specifications, Appendix A of DPR-56 for Unit 3 Peach Bottom Atomic Power Station, the following report is being submitted to the Directorate of Reactor Licensing as an Abnormal Occuerence.

Reference:

License Number DPR-56 Technical Specification

Reference:

Table 3 7 4 Report No.:

50-278-75-67 Report Date:

October 31, 1975 Occurrence Date:

October 21, 1975 Facility:

Peach Bottom Atomic Power Station R.D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

Excessive Icakage through the 1" - 276Y check valve in the nitrogen inerting system drywell purge supply to penetration N-205B.

Conditions Prior to Occurrence:

Reactor power 55%.

Description of Occurrence:

During local leak rate testing of the torus make-up supply isolation check valve, it was found to leak in excess of 2000 cc/ min.

8401130415 751031 u

PDR ADOCK 05000278 N

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i Mr. Reg:r S. Boyd 50-278-75-67 October 31, 1975 Page 2 Designation of Apparent Cause of Occurrence:

The check valve piston was found to hang up during operation, not allowing the check valve to seat properly.

Analysis of Occurrence:

The safety implications of this occurrence are minimal since the manual isolation valve was closed when the leakage was detected.

Corrective Action:

The manual isolation valve was verified to be leak tight in the closed condition. The check valve was repaired and the local le~ak rate test of the valve was repeated. The leak rate test performed af ter repairs was completed satisf actorily.

Failure Data:

' Abnormal Occurrence Report Numbers 50-277-75-33, 50-277-75-25 and 50-277-75-17 Very truly yours, M.

Cooney Su rintendent Generation Division - Nuclear cc:

Mr. J. 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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