TXX-4437, Deficiency Rept SDAR-165 Re Opening of Containment Spray Header Isolation Valves in Less than 20 S.Operators for Valves & All Associated Design Documents Will Be Modified to Slow Opening Time

Deficiency Rept SDAR-165 Re Opening of Containment Spray Header Isolation Valves in Less than 20 S.Operators for Valves & All Associated Design Documents Will Be Modified to Slow Opening Time

ML20112D095
Person / Time
Site:	Comanche Peak
Issue date:	03/11/1985
From:	Clements B TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Hunter D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
SDAR-165, TXX-4437, NUDOCS 8503220226
Download: ML20112D095 (2)

Text

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..<."' ..S! " ff"J.".LL. March 11, 1985 TXX-4437 Mr. D.R. Hunter, Chief Reactor Project Branch 2 U.S. Nuclear Regulatory Commission Office of Inspection & Enforcement 611 Ryan Plaza Drive, Suite 1000 Docket Nos.: 50-445 Arlington, TX 76012 50-446 COMANCHE PEAK STEAM ELECTRIC STATION CONTAINMENT SPRAY HEADER ISOLATION VALVES QA FILE: CP-85-04, SDAR-165 FILE NO.: 10110

Dear Mr. Hunter:

In accordance with 10CFR50.55(e), we are submitting the enclosed report of actions taken to correct a deficiency regarding containment spray header isolation valves that open in less than 20 seconds.

Supporting documentation is available at the CPSES site for your Inspector's review.

Very truly yours, F.R.Clements B

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Attachment cc: NRC Region IV - (0 + 1 copy) I dE Director, Inspection & Enforcement (15 copies)

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• e TXX-4437 3/11/85 Page~2 ATTACHMENT CONTAINMENT SPRAY HEADER ISOLATION VALVES

Description:

During preparation of proposed plant Technical Specifications, a discrepancy was identified by site engineering regarding the opening time of the containment spary header isolation valves. A subsequent review was performed which encompassed FSAR commitments, specification and test data, and review of calculations by the Architect / Engineer. - Preoperational testing confirmed the opening times of the valves were consistent with the acceptance criteria; and, the acceptance criteria, less than twenty (20) seconds, properly reflected the procurement specifications.

Review'of the calculations,. indicated that slow opening of the valves (approximately 117~ seconds) was required to prevent starting trips of the containment spray pump motors under design conditions. The discrepancy between the installed valves (and specifications) and the pump motor operating parameters results in a common mode failure which could defeat both safety train functions. The concern is applicable to Units 1 & 2.

Safety Implications In the event the deficiency had remained undetected, operability of containment spray system could not be assured.

Corrective Action The operators for the valves and all associated design documents will be modified to slow the opening time. In order to minimize these modifications, the valve logics will also be revised to close the recirculation valves coincident with the opening of the isolation valves. These actions will further ensure protection of pump motor operation.

Based upon procurement schedules for the valve operator replacement parts, these actions should be completed no later than July 31, 1985 for Unit 1.

Unit 2 activities will be performed prior to startup testing.