ML20086J059
| ML20086J059 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/02/1975 |
| From: | Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Anthony Giambusso Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20086J056 | List: |
| References | |
| AO-75-7, NUDOCS 8401230080 | |
| Download: ML20086J059 (2) | |
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d PHILADELPHIA ELECTRIC COMPANY 1
2301 MARKET STREET PHILADELPHIA. PA.19101 (2151 841-4o00 February 2, 1975 Mr. A. Giambusso Director, Division of Reactor Licensing
.0f fice of Nuclear Reactor Regulations United States Nuclear Regulatory Conmission Washington, DC 20555
Dear Mr. Giambusso:
Subject:
Abnormal Occurrence The following occurrence was reported to Mr. Tom Shedlowsky, NRC Region i Office of Inspection and Enforcement on January 24, 1975 Written notification was made to Mr. James P. O'Reilly, Region 1 Office of Inspection and Enforcement on January 24, 1975 In accord-ance with Section 6.7.2.A of the Technical Specifications, Appendix A of DPR-56 for Unit 3 Peach Rottom Atomic Power Station, the following report is oeing submitted to the Directorate of Reactor Licensing as an Abnormal Occurrence.
Reference:
License Number DPR-56 Technical Specification
Reference:
Table 3 1.1 Report No.:
50-278-75-7 Report Date:
February 2, 1975 Occurrence Date:
January 23, 1975 Facility:
Peach Bottom Atomic Power Station R.D. #1, Del ta, Pennsy lvania 17314 Identification of Occurrence:
Failure of the mode switch to consistently initiate a full scram signal when moved to the shutdown position.
Conditions Prior to Occurrence:
Unit 3 shutdc,wn.
Description of Occurrence:
Af ter insertion of all rods and placement of the mode switch in SHUTDOWN, the mode switch was placed in the REFUEL position to enable the movement of a single control rod. The mode switch failed to allow the motion of a control rod and the switch was then cycled to the 8401230000 750207 PDR ADOCK 0500027 -
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Mr. A. Giambusso February 2,1975 Page 2 S'HUTDOWN position and back to the REFUEL position to clear the problem.
This time the mode switch failed to initiate a full scram when moved to the SHUTDOWN position.
Designation of Apparent Cause of Occurrence:
Intermittent switch contact function.
Analysis of Occurrence:
Because the reactor was shutdown with all control rods in-serted, and because the Manual Scram System was operable, the failure of the full scram capability of the mode switch in the SHUTDOWN posi-tion has minimal safety implications.
Corrective Action:
The mode switch was cy: led many times between SHUTDOWN and REFUEL, and it intermittently failed to initiate full scrams. The mode switch was replaced.
Failure Data:
None.
Very truly yours, M.
. Cooney As t Gen' t Superintendent Generation Division cc:
Mr. J. P. O'Reilly, Director Office of Inspection and Enforcement Region i United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
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