ML20086F981

AO 75-64:on 751002,upper Isolation Valve to LS-2-3-231C Found Closed.Caused by Technician Error.Technicians Involved Interviewed & Seriousness of Error Stressed

ML20086F981
Person / Time
Site:	Peach Bottom
Issue date:	10/10/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Boyd R Office of Nuclear Reactor Regulation
Shared Package
ML20086F983	List: ML20086F981 ML20086F986
References
AO-75-64, NUDOCS 8401090749
Download: ML20086F981 (2)

Text

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PHILADELPHIA ELECTRIC COMPANY l 2301 MARKET STREET PHILADELPHI A. PA.19101 (21518414o00, October 10, 1975 Mr. Roger S. Boyd lC.

Acting Director T Division of Reactor Licensing Office of fluclear . Reactor Regulations '

7p United States Nuclear Regulatory Conmission Washington, DC 20555

Subject:

Abnormal Occurrence.

The following occurrence was reported to' Mr. Walt Baunack, Region 1, Of fice of Inspection and Enforcement, United States Nuclear Regulatory Co~nission on October 3,1975 Written notification was made to Mr. James P. O'Reilly, Region 1, Office of Inspection and Enforcement, United States Nuclear Regulatory Commission on October 3, 1975 In acccraance with Section 6 7.2.A of the Technical Specifica-tions, Appendix A of DPR-44 for Unit 2 Peach Bottom Atomic Power Station, the following report is being submitted to the Directorate'of Reactor Licensing as an Abnormal Occurrence.

Reference:

License Number DPR ;44 Technical Specification

Reference:

. Table 3 1.1 Report No.: 50-277-75-64 Report Date: October 10, 1975 Occurrence Date: October 2,.1975 F aci li ty: Peach Bottom Atomic Power Station R. D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

Closed upper isolation valve on LS-2-3-23 tc.

Conditions Prior to Occurrence:

Unit 2 operating at 55% power.

Description of Occurrence

l During routine instrument surveillance test,. the upper isolation i

valve to LS-2-3-231C (Scram Discharge Volume Hi Level Scram) was found l closed. ..

8401090749 751010 5000 guriGENTRENON ' m L 2

Mr. Roger S. Boyd -

October 10, 1975 50-277-75-64 ~

Page 2 Designation of Apparent Cause of Occurrence: '

The most probable cause for this occurrence is technician error in returning these instruments to seryice af ter the previous surveillance test. .

Analysis of Occurrence:

Failure of a single switch to function in a one-of-two-twice logic system does not render the logic system inoperable. Scram on high scram discharge volume level would still have occurred with this switch inoperable. Therefore, this occurrence has minimal safety implications. . .

Corrective Action:

of the errorThe technicians involved were interviewed and the seriousness stressed.

Failure Data: '

Valving errors on instruments covered by surveillance testing have been reported as S0-50-277-74-36, 50-278-74-10, 50-277-75-8 and 50-277-75-21.

-Very truly.yours,

, . . Cooney Sup[erintendent 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 1

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