ML20148E217

Final Deficiency Rept CP-87-90 Re Connection of Relief Valve Piping to RHR Pump Suction Piping.Initially Reported on 871120.Unit 1 Corrective Actions Will Be Complete by 880123. Unit 2 Actions Will Be Completed Per Const Schedule

ML20148E217
Person / Time
Site:	Comanche Peak
Issue date:	01/19/1988
From:	Counsil W, Woodlan D TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
CP-87-90, TXX-88109, NUDOCS 8801250583
Download: ML20148E217 (2)

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log # TXX-88109 Fi1e # 10110 r = 905.4 1UELECTRIC

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$$"",Sd%"$,,, January 19, 1988 U. 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 RHR RELIEF VALVE PIPING SDAR: CP-87-90 (FINAL REPORT)

Gentlemen:

On November 20, 1987, we notified you via our report logged TXX-6957 of a reportable design deficienc Residual Heal Removal (RHR)y Pumpregarding suction piping. relief valve The piping purposeconnected of this re)toortthe is to address the cause and implications of this condition, as well as t1e preventive action and corrective action implementation schedule, pursuant to the provisions of 10CFR50.55(e).

The cause of this deficiency appears to have been an inadvertent design / construction error resulting in excessive lengths of inlet / outlet piping for relief valves. As noted in our previous transmittal, this configuration results in an excessive pressure drop in the relief valve piping such that the required mass flow rate can not be achieved.

This deficiency was potentially applicable to other relief valve installations requiring a specific relief flow rate. 0 r review resulted in the identification of an additional deficiency which was determined not to be reportable docketed per SDAR-CP-87-87, "CVCS Relief Valve Piping."

Process calculations, pipe support analyses and the Design Basis Document DBD-ME-260, "Residual Heat Removal System", contain criteria governing these relief valve installations. These design documents will be used for future plant modifications, and will preclude repetition of these problems.

8801250583 880109 PDR ADOCK 05000445 /

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400 Nonh Olive Street L!t 81 Dallas. Texas 73201 i

TXX-88109 January 19, 1988 Page 2 of 2 The corrective action specified in our previous report (TXX-6957) to relocate the relief valves to comply with the requirements of Section 111 to the ASME Code, as well as the elimination of the large friction loss in the inlet piping of the reliet valves and a significant portion of the elevation difference between the valves and the suction lines, is scheduled for completion for Unit 1 by October 23, 1988. Unit 2 corrective actions will be completed in accordance with the general construction schedule.

This is our final report on this issue.

Very truly yours,

b. br.

W. G. Counsil By:

D. R. Woodlan Supervisor, Docket Licensing BSD/grr c-Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3)