TXX-6372, Final Deficiency Rept CP-86-74 Re Internal Wiring Discrepancies & Rusty Fittings in Terminal Boxes for Rockwell Msivs.Initially Reported on 861021.Issue Not Reportable Under 10CFR50.55(e)
| ML20209H726 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 04/27/1987 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CP-86-74, TXX-6372, NUDOCS 8705040106 | |
| Download: ML20209H726 (2) | |
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Log # TXX-6372
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File # 10110 908.3 E
C Ref # 10CFR50.53(e) nlELECTRIC Wliliam G. Counsil Esecutive Vice Presuknt U. 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 ROCKWELL TERMINAL B0XES SDAR: CP-86-74 (FINAL REPORT)
Gentlemen:
On October 21, 1986, we verbally notified your Mr. Ian Barnes of a deficiency regarding internal wiring discrepancies and rusty fittings in terminal boxes for main steam isolation valves supplied by Rockwell. Our last interim report, logged TXX-6176, was submitted December 19, 1986.
Verbal extensions for submission of this report were made with your Mr. Lee Ellershaw on April 10, 1987, and Mr. Cliff Hale on April 20, 1987.
Specifically, the affected terminal boxes contain wiring for limit switches for a solenoid actuated valve and a manually operated bypass valve associated with the Main Steam Isolation Valve (MSIV). The manually operated bypass valve utilizes the limit switches for position indication only. The manually operated bypass valve is only opened to equalize pressure around the MSIV prior to opening the first MSIV on plant startup. Only one MSIV bypass valve will be opened at a time. The manual operation of these valves during Modes 2, 3, and 4 will not significantly increase the potential for radioactive releases for postulated accidents requiring containment isolation.
This is based on:
1.
Lack of credible accident scenarios requiring containment isolation where MSIV bypass valves could significantly affect releases.
2.
Downstream valves (i.e., Turbine Stop valves, Auxiliary Feed Pump Turbine Steam Stop valves, Steam Dump valves and Steam Drain System) are closed, or are capable of remote manual closure in any containment isolation event.
3.
MSIV bypass valves are open for only a short time during each operating
-cycle. They will be locked closed during Mode 1 (power operation).
Therefore, the loss of position indication for the manual MSIV Bypass Valves will not have an adverse effect on plant safety. Also, if necessary, the valve position can be locally verified.
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5 TXX-6372
-April 27, 1987 Page 2 of 2 The solenoid valve limit switches are part of the MSIV test circuit and their failure will not prevent proper operation of the valve whether a short or open circuit is postulated for the limit switches.
The cer:clusion of our evaluation is that, had the deficiencies remained uncorrected, there would have been no adverse affect on the safety of plant operations. This issue is not reportable under the provisions of 10CFR50.55(e). Nonconformance reports have been issued to document and correct the discrepant conditions.
Records supporting this evaluation are available for your inspectors' review at the CPSES site, i
Very truly yours, i
M W. G. Counsil
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WJH/mlh c - Mr. E. H. Johnson - Region IV 4
Mr. D. L. Kelley, RI - Region IV 3
Mr. H. S. Phillips, RI - Region IV i
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