W3P85-0339, Final Significant Const Deficiency Rept SCD-93 Re Charging & Letdown Containment Isolation Valve Deficiency.Vendor Repaired Valve W/New Seats Sized for Max Interference Fit

Final Significant Const Deficiency Rept SCD-93 Re Charging & Letdown Containment Isolation Valve Deficiency.Vendor Repaired Valve W/New Seats Sized for Max Interference Fit

ML20107N056
Person / Time
Site:	Waterford
Issue date:	02/21/1985
From:	Cook K LOUISIANA POWER & LIGHT CO.
To:	Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
SCD-93, W3P85-0339, W3P85-339, NUDOCS 8503060200
Download: ML20107N056 (3)

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2 0 W E R & L I G H T / New oRL.ANS LoutSWM 70174-8000 9 (504)3864345 VaPases@

February 21, 1985 W3P85-0339 Q-3-A35.07.93 3-A1.01.04 A4.05 Mr. Robert D. Martin Regional Administrator, Region IV )h @))y] h U.S. Nuclear Regulatory Commission F-611 Ryan Plaza Drive, Suite 1000 i Arlington, TX 76011  ! FEB 2 51985

Subject:

Waterford 3 SES Docket No. 50-382 ,

SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 93

" Charging and Letdown Containment Isolation Valve Deficiency" Final Report

Reference:

LP&L letter W3K84-2965 dated October 31, 1984 The referenced letter provided an interim report on SCD-93 with the

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Justification for Interim Operation. it stated that the final report would be submitted upon the completion of response time testing.

In accordance with the requirements of 10CFR50.55(e)(3' , enclosed are two copies of the Final Report of SCD-93.

Very truly yours, Y

K.W. Cook Nuclear Support & Licensing Manager KWC:GEW:sms cc: NRC, Director, Office of I&E G.W. Knighton, NRC-NRR D.M. Crutchfield, NRC-NRR NRC Resident Inspectors Office INPO Records Center (D.L. Gillispie)

E.L. Blake W.M. Stevenson 8503060200 850221 PDR S

ADOCK 05000382 PDR

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e W3P85-0339 FINAL REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 93

" LETDOWN CONTAINMENT ISO VALVE 1CH-F-2501 A/B" INTRODUCTION This report is submitted pursuant to 10CFR50.55(e). It describes the failure of valve ICH-F-2501 A/B (CVC-103) to close following Hot Functional Testing (HFT) .

This problem is considered reportable under the requirements of 10CFR50.55(e).

To the best of our knowledge, this deficiency has not been reported to the USNRC pursuant to 10CFR21.

DESCRIPTION OF PROBLEM Following the cooldown af ter HFT, it was discovered that the valve ICH-F-2501 A/B (CVC-103), (supplied by WKM), was stuck in the open position. This valve had been exposed to 550*F service temperature for several days during HFT of the charging and letdown system.

It appears that the malfunction occurred due to upstream float of the seat which reduced the clearance between the seat and the gate, thereby causing the gate to stick open.

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SAFETY IMPLICATIONS Valves ICH-F-2501 A/B (inside Containment, powered from SB division) and 2CH-F-1518 A/B (outside Containment, SA division) provide containment isolation for the letdown line. Failure of ICH-F-2501 A/B to close would violate the isolation requirements of GDC55. Although there is in fact another safety class 1 valve (ICH-F-1516 A/B) upstream of the affected valve (ICH-F-2501 A/B), which -

would automatically close on high containment pressure or low pressurizar pressure, it is powered from the SA division. The requirements for independent power sources would therefore, not be met if valve ICH-F-2501 ' A/B failed to close.

CORRECTIVE ACTION Vendor (W2i) service technician has repaired the valve with new seats which are sized for maximum interference fit in the seat' pocket in order to eliminate the previously experienced seat float. The closure of this valve has since been satisfactorily tested in the cold fluid condition.

The closure and operability of the valve ICH-F-2501 A/B has also been tested during post core hot functional test temperature ascention and full temperature conditions. In all instances the valve operated satisfactory and closed in approximately 1.5 seconds. FSAR commitment for closure of valve ICH-F-2501 A/B is 10 seconds.

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W3P85-0339 SCD NO. 93 Page 2 In accordance with the valve testing procedure, the valve ICH-F-2501.A/B will '

also be tested during plant cooldown when plant conditions permit it, to ensure that it operates satisfactorily during decreasing temperature conditions.

Technical Specification 3.6.3 would be enforced in the unlikely event if valve >

ICH-F-2501 A/B would fail the completion of the tests.

The containment isolation valves which operate at temperature 250'F or higher have been evaluated for generic implications. There is only one other valve of similar design (2CH-F-1518 A/B) which is also used for letdown line isolation outside containment. This valve closed satisfactorily in 2.6 seconds during testing in cold condition.

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. The above valves are double disc gate valves specifically designed to ensure minimum possible leakage. Other containment isolation valves are of simpler design and are not applicable for generic failure analyses. Also, all containment isolation valves have been tested in cold condition- and closed satisfactorily to meet FSAR conmitments.

Problems which occur during routine eighteen month surveillance tests will be handled -in accordance with administrative procedures and technical specifications.

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