ML20086F981
| 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: |
| References | |
| AO-75-64, NUDOCS 8401090749 | |
| Download: ML20086F981 (2) | |
Text
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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET PHILADELPHI A. PA.19101 (21518414o00, October 10, 1975 lC.
Mr. Roger S. Boyd Acting Director T
Division of Reactor Licensing 7p Office of fluclear. Reactor Regulations United States Nuclear Regulatory Conmission Washington, DC 20555
Dear Mr. Boyd:
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 50-277-75-64
~
October 10, 1975 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:
The technicians involved were interviewed and the seriousness of the error 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, Sup[erintendent
. Cooney Generation Division - Nuclear Mr. J. P. O'Reilly cc:
Director, Region 1 Office of Inspection and Enforcement United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
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