TXX-4975, Part 21 & Deficiency Rept CP-86-31 Re Failure of Rubber Facing on Diesel Generator Lube Oil Sump Tank Foot Valves. Initially Reported on 860418.Evaluation Continuing.New Liners Being Procured.Next Rept Will Be Submitted by 861126

Part 21 & Deficiency Rept CP-86-31 Re Failure of Rubber Facing on Diesel Generator Lube Oil Sump Tank Foot Valves. Initially Reported on 860418.Evaluation Continuing.New Liners Being Procured.Next Rept Will Be Submitted by 861126

ML20212P272
Person / Time
Site:	Comanche Peak
Issue date:	08/22/1986
From:	Counsil W, Keeley G TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Johnson E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
REF-PT21-86-319-000 CP-86-31, PT21-86-319, PT21-86-319-000, TXX-4975, NUDOCS 8609030057
Download: ML20212P272 (2)

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_ . . Log # TXX-4975 File # 10110 909.5 TEXAS UTILITIES GENERATING COMPANY SKYWAY TOWER . 400 NORTH OLIVE STREET. I.B. 5 5

• DALLAS. TEXAN 75201 August 22, 1986 33 = L T."1.5 @@@0MM AUG 21l986 Mr. Eric H. Johnson, Director Division of Reactor Safety and Projects

'g j j U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76012

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NOS. 50-445 AND 50-446 DIESEL GENERATOR LUBE OIL SUMP TANK FOOT VALVES SDAR: CP-86-31 (INTERIM REPORT)

Dear Mr. Johnson:

On April 18, 1986, we verbally notified your Mr. R. Hall of a deficiency involving the possible failure of the rubber facing on foot valves mounted in the diesel generator lube oil sump tank. We have submitted an interim report logged TXX-4813, dated may 19, 1986. We have concluded that this deficiency is reportable under the provision of 10CFR50.55(e). The evaluation of this issue is continuing and we anticipate submitting our next report by November 26, 1986.

Very truly yours, bUk Sw&b W. G. Counsil By: / -

G.S. Keeley

~M Manager, Nuclear ' c nsing JCH/amb Attachment c - NRC Region IV (0 + 1 copy)

Director, Inspection & Enforcement (15 copies)

U. S. Nuclear Regulatory Commission Washington, D.C. 20555 86090300S7 860022 PDR ADOCK 00000445 S PDR I

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ATTACHMENT DG LUBE OIL SUMP TANK FOOT VALVES DESCRIPTION As a result of a 10CFR21 notification provided by the supplier (Delaval), an investigation was initiated involving the diesel generator lube oil sump tank foot valves. The specific Part 21 notice cited the failure at another nuclear facility of the elastomer liner in the foot valve mounted on the lube oil su.np tanks.

Evaluation of this issue for plant specific applicability included inspection of the Unit I diesel generator foot valve installations. These inspections confirmed damage to all four valve liners including one to the extent proper sealing was precluded. The cause of the damage appears to be overpressurization. This apparent cause is consistent with the supplier's determination.

This deficiency is applicable to both Units 1 and 2.

SUMMARY

DE EVENTS Date Discovered: March 19, 1986 per vendor Part 21 notice.

Date NRC notified as potentially reportable: April 18, 1986 Interim Report to NRC: May 19, 1986 Date Determined Reportable: August 22, 1986 SAFETY IMPLICATION In the event this condition had remained undetected, failure of the foot valve liner could result in restriction or damage to the lube oil pump thereby affecting diesel engine availability.

CORRECTIVE ACTION Based upon the supplier recommendations, procurement documents have been initiated to purchase new liners made of Viton to replace the liners in the Unit I and 2 installations. The current scheduled receipt date is September 5, 1986. Unit 1 foot valves liners will be installed upon receipt. Unit 2 liners will be repaired after the lube oil flush, tentatively scheduled for completion in late October, 1986.