ML20195H951
| ML20195H951 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/11/1988 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CP-88-09, CP-88-9, TXX-88068, NUDOCS 8801200428 | |
| Download: ML20195H951 (2) | |
Text
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k, MEE Log # TXX-88068 1
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January 11, 1988 V. S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, D.C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION DOCKET NOS. 50-445 AND 50-446 ELECTRICAL PENETRATION OVERLOAD PROTECTION SDAR: CP-88-09 (FINAL REPORT)
Gentlemen:
We are hereby reporting a significant deficiency involving the overloading of and the lack of backup protection devices for Class 1E and non-Class IE electrical penetrations.
This deficiency is reportable under the provisions of10CFR50.55(e).
The required information follows.
DESCRIPTION OF DEFICIENCY Several deficiencies were found during a review of design documents for electrical penetrations short-circuit failure and protection and ampacity of electrical containment penetrations.
CASE 1:
Back-up protection for some containment electrical penetration assembly circuit conductors is either non-existent or incomplete.
CASE 2:
Primary and/or back-up protection devices for many containment electrical penetration assembly circuit conductors are either set to pickup and clear at values of current higher than the rated penetration conductor continuous rating or have time-current characteristics which do not coordinate with the rating of the penetration conductor.
CASE 3:
The momentary short-circuit current of the module conductors exceeds the short-circuit rating of the penetrations. All electrical panetrations have been reviewed as part of the Corrective Action Program and all such deficiencies have been identified.
This deficiency was apparently caused by a failure to adequately meet the electrical penetration overload protection criteria described in the CPSES FSAR.
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e TXX-88068 January 11, 1988 Page 2 of 2' SAFETY IMPLICATIONS If left uncorrected, the conditions discussed above could cause electrical penetrations to exceed their_short-circuit current rating or the time limit for which they can withstand a rated continuous current overload.
These conditions could shorten a penetration's qualified life span and may cr.use penetration breakdown, which could result in Class lE system breakdown and for loss of containment pressure integrity.
This is a significant deficiency in the final design as approved and released for construction such that the design does not conform to the criteria and bases stated in the FSAR.
If this condition were to have remained uncorrected, it could have adversely affected the safe operations of the plant.
CORRECTIVE ACTIONS The design criteria for containment electrical penetration protection has been documented in design basis document DBD-EE-062, "Containment Electric Penetration Assemblies".
In order to comply with the design criteria, the following solutions will be applied as required to resolve the issues.
1.
Replace or add protective devices of the appropriate ratings.
2.
Reroute cables to appropriate penetrations.
.a 3.
Parallel penetration conductors.
4.
Develop new relay settings.
These activities will be completed no later than October 20, 1988.
Very truly yours,
$O71dC W. G. Counsil WJH/grr c-Mr. R. D. Martin, Region IV Resident inspectors, CPSES (3)