ML20082D334
| ML20082D334 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 11/14/1983 |
| From: | Hall D ILLINOIS POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 1605-1, 1605-L, 55-83-09, 55-83-9, U-10108, NUDOCS 8311220393 | |
| Download: ML20082D334 (3) | |
Text
h 16 05-L ILLIN0/S POWER 00MPANY y.lolog gy CLINTON POWER STATION, P.O. BOX 678. CLINTON. ILLINOIS 61727 November 14, 1983 Docket No. 50-461 Mr. James G. Keppler Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road I
Glen Ellyn, Illinois 60137
Subject:
Potential Deficiency 55-83-09 10 CFR 50.55 (e)
Damage to PGCC Cable Connectors
Dear Mr. Keppler:
On June 29, 1983, Illinois Power Company notified Mr. F.
Jablonski, NRC Region III (Ref:
IP memorandum Y-17130, 1605-L, dated June 29, 1983) of a potentially reportable deficiency concerning damage to conductor pins and sockets in cable connectors used on the Power Generation Control Complex (PGCC).
Our investigation of this matter has determined that the issue is not reportable under 10CFR50. 55 (e).
This letter represents a final report in accordance with 10CFR50.55(e)(3).
Statement of Potentially Reportable Deficiency Bent conductor pins were discovered in twenty-three (23)
PGCC cable connectors when the plugs and receptacles were disconnected.
The dielectric between the conductor sockets of receptacle connectors was found to be punctured by the bent pins of the matching plugs when the parts were coupled.
Electrical contact may not have been completed, and the integrity of the electrical circuits was questionable.
Background / Investigation Results The cable connectors are manufactured by Amphenol, Bendix, and Cannon and were furnished by General Electric Co.
They are interchangeable, plug and receptacle connectors, having multi conductors, an alignment guide, and a screw-type coupling ring.
The connectors have been standard in the electrical industry for many years and manufacturers do not provide specific installation instructions for mating the connectors.
There are approximately 7600 cable connectors used in the PGCC of which approximately 45 percent are shipped as factory coupled and tested.
The remaining cable connectors are mated in the field.
Field electrical craftsmen receive a gpble instal-
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Mr. Jam:s G. Keppler Page 2 November 14, 1983 lation training program before making these final connections.
Visual inspections of the integrity of the connection is not possibic when the connector is coupled, but verification of the electrical circuit is made by a functional circuit test.
Of the 23 cable connectors with 27 misaligned pins (27 wire connections out of approximately 460 total wire connections for the 23 connectors) that were identified as nonconforming, only three wire connections were previously functionally tested.
These three connections were tested satisfactorily thru the connectors.
Therefore, although the pins and sockets in the connector were not joined in the normal manner, satisfactory electrical contact was made.
The remaining connections were scheduled for future circuit functional testing.
The group of PGCC panels associated with these 23 cable connectors have a total of 720 cable connectors and approximately 14,000 wire connections, all of which were disconnected.
There-fore, with 23.nonconformances, the error rate was less than 0.2 percent.
This specific group of panels were replaced at Clinton Power Station in September 1981 and the cables were reconnected at,that time.
IP's experience with functional circuit testing on many other PGCC balance of plant circuits has identified this similar type of problem in proportionally fewer cases.
General Electric, supplier of the PGCC, also reviewed their factory test records for the total equipment provided to CPS and reported that out of 7600 cable connectors with approximately 152,000 wire connections, only 85 wire connections were identified with problems.
A PGCC cable installation and termination procedure BAP 3.3.7 is used by the Contractor (Baldwin Associates) to train field electricians and quality control inspectors in proper installation and inspection methods.
This procedure requires checking the cable connector keyway, alignment, and inspection for damage, i.e., bent pins and dielectrics.
IP Startup Testing Technicians and IP Maintenance Technicians also have access to these cable connectors.
Neither of these groups have formal training procedures for working with cable connectors, however, they are developing training procedures and are aware of the potential problems with the cable connectors and use proper caution in coupling the connectors.
~
Corrective Action The scope of the problem with cable connectors has been determined to be minimal and detectable by functional circuit testing.
The nonconformances in the cable connectors will be repaired or replaced where required.
The condition appears to be caused by the amount of attention and manner used to couple the connectors.
Training will be expanded and improved with a special " hands on training workshops" for work on cable connec-tors by the contractor and IP technicians to further reduce the occurrence of problems.
Additionally, a " cutaway" hardware demonstration card (similar to what GE uses in factory training) will be provided for field training.
Mr. Jamas G. Kcppler Page 3 November 14, 1983 Safety. Implications / Significance This investigation has determined'that problems with the PGCC ' cable connectors are minimal and detectable by functional circuit' testing.
Tliere is no indication that a deficiency exists in.either design requirements or in construction that could adversely affect the safety of operation of CPS.
Therefore,'this issue is not reportable under the provisions of 10CFR50.55(e).
We trust;that this~ final report provides sufficient information t-o perform a general assessment of this issue and adequately described our overall approach to resolve the problem.
Sincerely yours,
D. P. Hall Vice President RDW/j f I
cc:
NRC Resident Office Director, Office of I&E, USNRC, Washington, DC 20555 Illinois Office of Nuclear Safety INPO Records Center g
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