ML20006D873

Supplemental Deficiency Rept CP-88-41 Re Westinghouse W-2 Type Cell Switches.Initially Reported on 881202.Cell Switches & Spring Retainer Assemblies Replaced at Unit 1. Cell Switches Will Not Be Replaced at Unit 2

ML20006D873
Person / Time
Site:	Comanche Peak
Issue date:	02/07/1990
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CP-88-41, TXX-90058, NUDOCS 9002150165
Download: ML20006D873 (2)

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Log # TXX-90058 File # 10110

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filELECTRIC-.

February 7, 1990

%11tism J. Cahm. Jr.

. EnecuIn Vice hesident U.1 S. Nuclear Regulatory Commission

' Attn Document Control Desk Washington, D. C. 20555

SUBJECT:

COMANCHE-PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NOS. 50-445 AND 50-446 W-2 TYPE CELL SWITCHES SDAR: CP-88-41 (SUPPLEMENTAL REPORT)

Gentlemen:

On December 2, 1988. TV Electric notified the NRC of a deficiency involving Westinghouse W-2 type cell switches. The final report on this issue, logged TXX-89645, was dated September 5, 1989. This report revises the corrective action discussed in that. final report.

TV Electric has reevaluated the safety significance of this deficiency by analysis of the specific applications and functions of the Westinghouse W 2 cell switches utilized in the Class 1E 480V switchgear load. breakers, feed and tie breakers, and reactor trip breakers. The previous evaluation had not-

. included,such~a detailed review. -This reevaluation concluded that if any of the cell switches were to fail, it would not adversely affect the safety of plant' operations. However, due to the performance and specification deviation of W-2 cell switches - TV Electric still considers this issue as reportable

, pursuant to 10CFR50.55(e).

. In TXX-89645 TV Electric stated that it would replace the W-2 cell switches 1.n the 480V switchgear for Units 1 and 2. TV Electric has replaced the W 2 cell switch or spring retainer assembly for the Unit 1 W-2 cell switches (i.e., some of the Unit 1 cell switches were replaced and the rest were reworked and backfit with new spring retainer assemblies). Based on the conclusions derived from evaluations-for the Unit 1 W-2 cell switches, TV' Electric does not plan to replace the Unit 2 W-2 cell switches in the Uni.t 2:480V switchgear. Pre-operational testing will be conducted to assure that these Unit 2 W-2 cell switches are functional.

The second corrective action stated in TXX-89645 was to perform continuity checks each time a circuit breaker is removed from its connected position.

This action is no longer required, since our evaluation of the applications of the cell switches concluded that failure of the cell switches at CPSES would not adversely affect plant safety.

9002150165 900207 p pR ADOCK 0500 g 5 400 North Olive Street LB. BI Dallas, Texas 75201 0

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v- TXX 90058-fj - February _ 7,11990 Page 2 of 2 The-third and last corrective action stated in TXX-09645 was to perform inspections every five years. These periodic inspections will be performed as normal preventive maintenance. The results of the first periodic inspections will determine whether future inspections are warranted.

As an additional action..TU Electric has listed the W 2 cell switches on the Nuclear Operations Defective Item List. This will ensure that these switches ,

will not be procured for use in any future design modifications that could create a condition adverse to safety.

Corrective actions, as described above, are complete. Documentation supporting our conclusions is available for your review.

Sincerely, William J. Cahill, Jr.

By:

D. R. Woodlan Docket Licensing Manager WJH/vid c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3) i L

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