TXX-8803, Interim Deficiency Rept CP-87-130 Re Svc Water Sys Water Hammer.Initially Reported on 871207.Vacuum Breakers Will Be Installed in Emergency Diesel Generator Jacket Water Coolers.Next Rept Will Be Submitted by 880215

Interim Deficiency Rept CP-87-130 Re Svc Water Sys Water Hammer.Initially Reported on 871207.Vacuum Breakers Will Be Installed in Emergency Diesel Generator Jacket Water Coolers.Next Rept Will Be Submitted by 880215

ML20235A764
Person / Time
Site:	Comanche Peak
Issue date:	01/06/1988
From:	Counsil W, John Marshall TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
CP-87-130, TXX-88034, NUDOCS 8801120432
Download: ML20235A764 (2)

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Log # TXX-88034 1 _""" File f 10110 j- - = r. 909.2

.Ref. # 10CFR50.55(e) 7UELECTRIC E,II,S@S,Y,= January 6,1988 V. 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 SERVICE WATER SYSTEM WATER HAMMER

'SDAR: CP-87-130 (INTERIM REPORT)

Gentlemen:

.On December 7,1987, we verbally notified your Mr. I. Barnes of a deficiency involving the water hanner and column separation in the Service Water System. -

-We are reporting this issue under the provisions of 10CFR50.55(e) and the required information follows.

Description The design validation process of the Service Water (SW) System revealed piping high points at the inlet.and outlet of the emergency diesel generator jacket water coolers at which water column separation can occur subsequent to a service water pump trip. Specifically, the SW System Water Hammer Test Sunnary (REl-701-SSW) indicated that the water hanner develops during column rejoining, and could result in pipe and/or pipe support damage and thereby cause a loss in emergency diesel generator cooling. water.

The cause of the described deficiency is the piping configuration which is conducive to water column separation during' service water pump trip and restart events. This could occur during normal operation or during a loss of offsite power when the service water pumps stop and are sequenced onto the emergency diesel generators.

This problem is restricted to the Service Water System as indicated by the Water Hammer Test Summary.

Safety Implications The . operation of the emergency diesel generator is required during plant upset and accident conditions to mitigate the consequences of an accident and/or  !

l safely shut down the plant. Should a water hammer cause a break in the inlet or outlet lines of the emergency diesel generator jacket water coolers, the loss of cooling water and/or flooding of the diesel generator building could cause the inoperability of the emergency diesel generator.

8801120432 880106 3ruh Ohve Street Lilof Dallas, T,xas 7201 h

//}I PDR ADDCK 05000445 S PDR q

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l TXX-88034 January 6,1988 Page 2 of 2 g Corrective Action To correct this deficiency, vacuum breakers will be' installed in the emergency l diesel generator jacket water coolers to prevent inadvertent generator shut down due to loss of cooling water and for flooding. ,

We are continuing our evaluation and our next report will be submitted no.

later than February 15, 1988 to provide the scheduled completion date for these activities. i gery truly yours, kl C Cov a u (

W. G. Counsil

'}l By: - # /'/ b ek J. S. Marshall Supervisor, Generic Licensing MCP/grr ,

c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3) 1 _ _ _ _ _ _ _ . - _ _ _ _ _ _ _ _ _ _ _ _