TXX-7081, Interim Deficiency Rept CP-87-29 Re Component Cooling Water Isolation Following Reactor Coolant Pump Rupture.Initially Reported on 870629.Non-Class 1E Temp & Flow Instrumentation Replaced W/Class 1E Equipment.Next Rept Due by 880217
| ML20237B116 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/11/1987 |
| From: | Counsil W, Woodlan D TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CP-87-29, TXX-7081, NUDOCS 8712160032 | |
| Download: ML20237B116 (2) | |
Text
_ _ _ _
f
- s 7.m..
l M
Log # TXX-7081
==
File # 10110 L
d 909.2
,=
=
Ref. # 10CFR50.55(e) 1UELECTRIC December 11, 1987 William G. Counsil knecutive Vkv Prevdent U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555
SUBJECT:
COMANCNE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET N05. 50-445 AND 50-446 COMPONENT COOLING WATER (CCW) ISOLATION FOLLOWING REACTOR COOLANT PUMP (RCP) THERMAL BARRIER RUPTURE SDAR:
CP-87-29 (INTERIM REPORT)
Gentlemen:
On June 29, 1987, we verbally notified your Mr. H. S. Phillips of a deficiency involving instrumentation and controls used for isolation of component cooling water (CCW) to the reactor coolant pump (RCP) thermal barrier heat exchanger.
Our latest interim report logged was TXX-6980, dated November 20, 1987. We have concluded this issue is reportable under the provisions of 10CFR50.55(e).
The require information follows.
De_scription A recent design review has revealed that the main control board instrumentation used to indicate a reactor coolant pump thermal barrier rupture is non-Class 1E.
In addition, a single isolation valve is provided on the upstream component cooling water lines.
Safety Implication Accurate and reliable safety-related main control board indication is necessary to allow adequate and timely operator response in accordance with ANSI /ANS 58.8-1984 and ensure successful manual isolation of the CCW system in the event of thermal barrier rupture.
Redundant valves must be provided to ensure closure following a single failure.
If 39th design features are not provided, a rupture of the reactor coolant thermal barrier could lead to the uncontrolled release of reactor coolant.
9 Y
8712160032 871211 0
DR ADOCK 0500 5
x) Nonh Olne Street LB 81 Dalla. Texas 73201
l W mW IXX-7081 December 11, 1987 l
Page 2 of 2 1
Corrective Actions To correct this condition, the following corrective actions will be implemented:
1.
Replacement of the existing non-Llass 1E temperature and flow instrumentation with Class 1E equipment.
2.
Installation of a second check valve in the CCW inlet piping of each thermal barrier to provide redundant isolation.
Our next report will be submitted no later than February 17, 1988, which will address the implications (if any) and cause of this condition as well as the schedule for completion of the above corrective actions.
Very truly yours, b.b b W. G. Counsil By:
D. R. Woodlan Supervisor, Docket Licensing MCP/grr c - Mr. R. D. Martin, Region IV Resident inspectors, CPSES (3) l
____ a