ML19341A306
| ML19341A306 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 01/14/1981 |
| From: | Davidson D CLEVELAND ELECTRIC ILLUMINATING CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8101220565 | |
| Download: ML19341A306 (2) | |
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.e THE CLEVELAND ELECTRIC ILLUMIN ATING COMPANY P.O. Box 5000 e CLEVELAND. OHIO 44101 s TELEPHONE (216) 622 9800 e ILt '.'MINATING BLoG. m $5 PUBLIC SoVARE Serving The Best Location in the Nation Dalwyn R. DcvidSon WCE PRESIDENT SYSTEM ENG6NEERING AND CONSTRUCTION January 14, 1981 Mr. James G. Keppler Director, Region III Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 799 Roosevelt Road i
Glen Ellyn, IL 60137 Re: Perry Nuclear Power Plant Interim Report RPS Flexible Conduit Grounding in PGCC
Dear Mr. Keppler:
Installations This letter will serve as the interim report as required by 10CFR50.55(e) on the potential significant deficiencies concerning the Reactor Protection System (RPS) Flexible Conduit Grounding in Power Generation Control Complex (PGCC) Installations. The defect is in the flexible conduit that is used to enclose electrical conductors in various fail-safe circuits which are part of the RPS.
General Electric notified the NRC of this reportable deficiency per 10CFR, Part 21, on October 29, 1980. These items were discussed during a telephone conversation between NRC resident inspector Jack Hughes and Region III, Office of Inspection and Enforcement on December 18, 1980.
Description of Deficiency The flexible conduit is contained in PGCC equipment designed and supplied by the Control and Instrumentation Department in the Nuclear Engineering Business Group of the General Electric Company in San Jose, California. The flexible conduit is used in the RPS, Nuclear Steam Supply Shutoff System (NSSSS) and Neutron Monitoring System (NMS) logic. The reportable condition was identified in a letter from General Electric to The Cleveland Electric Illuminating Company dated December 3, 1980. The potential defect concerns the potential loss of solid metallic grounding of the flexible conduit either at the termination cabinet or at the panel.
This has the potential for preventing operation of fail-safe (de-energize to operate) logic associated with the RPS.
I The flexible conduit runs from a panel on a specific floor section, is routed in the floor section, and finally is terminated in a termination cabinet at the end of that floor section.
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In a typical termination cabinet installation, the conduit is firmly attached with a locking ring to a termination module. This is an acceptable ground connection; however, the termination module is ultimately mounted on a painted g),yf.s S (high electrical resistance) surface. There is no procedure to insure that
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a4 Mr. Jrmes G. Kappler January 14, 1981 paint is removed from panel surfaces before termination modules are mounted.
There is also no known procedure to check that the termination module makes a low resistance connection to the panel steel. General Electric's recommended corrective action requires attaching ground at both ends of the conduit PGCC i
where inadequate grounding is fcand. For PGCC still in fabrication the recommended corrective action is removal of paint from grounding surfaces.
A final report will be written to inform you of the corrective action taken and of the progress made in resolving the grounding problems by July 1, 1981.
Very truly yours, bW A/
Dalwyn. Davidson Vice P esident System Engineering and Construction ec: Jack Hughes Director of Inspection & Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 4
i U.S. Nuclear Regulatory Commission c/o Document Management Branch Washington, DC 20555 13/T/2 I
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