ML17275A545

Deficiency Rept Re Possible Inoperability of Borg-Warner Valves W/Limitorque Series Smc Operators.Identified Valves Will Be Reworked by Thread Staking Procedure.Schedule to Be Provided After Labor Negotiations

ML17275A545
Person / Time
Site:	Columbia
Issue date:	08/20/1980
From:	Renberger D WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:
References
10CFR-050.55E, 10CFR-50.55E, GO2-80-184, NUDOCS 8008260534
Download: ML17275A545 (6)

Text

REGULATOR INFORMATION DISTRIBUTION 'TEM (BIDS)

ACCESSION NBR 8008260534 DOC ~ DATE! "80/08/20 NOTARIZED! NO DOCKET FACIL:50 BYNAME 397 'iilPPSS Nuclear Projects Unit 2s Washington Public Powe 03 AUTH AUTHOR AFFILIATION RENBERGER,D ~ L ~ Washington Public Power Supply System RECIP,NAME RECIPIENT AFFILIATION

SUBJECT:

Deficiency r ept re possible operability loss of Borg"Warner valves w/l imi torque ser ies SMC oper ators. Identi f ied valves wi l l, be rewor ked by thread. staking procedure,Schedul e to. be provided after labor

&ENCL 4- SIZE:

negotiations'ISTRIBUTION CODE: SO I OS COPIES RECEIVED:LTR TITLE: Construction materially Deficiency Report (10CFR50 ~ 55K)

NOTES:PM; 2 copies of all 05000397 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL IO CODE/NAME LTTR ENCL ACTION: A/D LICENSNG 04 1 1 YOUNGBLOODPB 05 1 1 RUSHBROOKPMO 06 1 LYNCHED, 07 1 1 INTERNAL: AD/RCI/IE 17 1 1 AEOD 18 1 1 ASLBP/J ~ HARD 0/D IR HUM F AC15 1 1

'l 1 1 DIRE HUM FAC S10 1 1 EDO 8 STAFF 19 1 1 EQUIP QUAL'R 1 1 1 1 I8E 09 2 2 LIC QUAL BR 12 1 1 MPA 20 1 1 NRC PDR 02 1 1 OELD 21 1 1 PROC/TST REV 13 1 1 QA BR 1 1 01 1 1 RUTHERFOROPW ~ IE 1 1 STANDRDS DEV 21 1 1 EXTERNAL: ACRS 16 16 16 LPDR 03 1 1 NSIC 08 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR A ENCL AQ

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ol Washington Public Power Supply System A JOINT OPERATING AGENCY

p. o. Box 958 3000 Gco. wAs~i~oro~ wAr Ric~<A~o. wAIRiNoro~ 99352 p~o~c (509) 375 5000 G02-80-184 August 20, 1980 Docket No. 50-397 Nuclear Regulatory Commission Region V Suite 202, Walnut Creek Plaza 1900 N. California Blvd.

Walnut Creek, California 94596 Attention: Nr. R. H. Engelken, Director

Subject:

WPPSS Nuclear Project No..2 Docket No. 50-397, CPPR-93 Re ortable Deficienc - 10CFR50.55 e In accordance with the provisions of 10CFR50.55(e) your staff was informed by telephone on July 24, 1980, of a reportable deficiency relative to Borg-Warner valves with Limitorque Series SNC motor operators, which could result in the loss of valve operability. The deficiency was initially identified in a 10CFR21 Preliminary Notification Report to the Commission by the Borg-Warner Nuclear Valve Division on Nay 23, 1980.

Attached is our report on this deficiency.

Please contact us if'ou have additional questions.

very truly yours, D. L. Renberger Assistant Director, Technology DLR:HLB:cph attachment cc w/att: JR Lewis - BPA ND Lewis -, EFSEC, Olympia RE Snaith - BKR, NY

-JJ Verderber, BKR, NY B. W~ood NUS Corp.

~V-.-Stel-l o---ARC AD Toth - NRC WNP-2 Files 8<<835pg gy

REPORTABLE DEFICIENCY AND CORRECTIVE ACTION WPPSS NUCLEAR PROJECT. NO. 2 POSSIBLE LOSS IN OPERABILITY OF BORG-WARNER-NDV VALVES WITH LIMITOR UE SMC SERIES ACTUATORS WASHINGTON PUBLIC POWER SUPPLY 'SYSTEM DOCKET NO. 50-397 LICENSE NO. CPPR-93 Descri tion of Deficienc  :

The reported deficiency involves the possible loosening of the stem nut on some Borg-Warner Nuclear Valve Division valves equipped with Limitorque SMC series operators. Loosening of the stem nut could result in disengage-ment of the connection between the valve and operator, rendering the valve inoperable.

The deficiency is similar to that reported by NRC IE Circular 79-04, however, the design of the connection between the valve and operator is not the same as described by the Circular and involves components provided by the valve manufacturer. The design, for which the deficiency is reported, applies to valves with .threaded rising stems that rotate. The required axial movement of valve stem is provided by the interaction between the valve stem threads and a fixed insert nut installed in a flange fitting between the valve assembly mount flange and the operator.

Rotation of the valve stem is provided by a splined stem nut which mates with splines in the hub of the operator drive gear. The stem nut, which has a square socket to mate with a squared section of the valve stem, is retained by a nut on the end of the valve stem. The stem nut moves axially with the valve stem as the valve opens or closes. Loosening or loss of the retainer nut could result in movement of the stem nut to a point that the connection between the;valve and operator disengages.

Safet *Im'lications:

A total of twenty-six (26) valves have been identified by the Borg-Warner Nuclear Valve Divison as supplied for the WNP-2 Project and subject to the reported deficiency. Four (4) valves are employed in the safety related Residual Heat Removal (RHR) system. Sixteen (16) valves are used in non-safety related systems. Six (6) valves have no end use designation assigned at this time.

The valves, in the RHR system. serve a containment isolation function during accident conditions. Failure of the valves, in the manner described could result in a violation of containment integrity.

Attachment Page 2 Corrective Action:

The Borg-Warner Nuclear Valve Divison has developed a'ethod of correcting the reported deficiency which involves staking the threads of the valve stem and retainer nut as indicated on Figure 1. This staking procedure has been tested with very satisfactory results.

All of the valves, which have been identified, will be reworked in accordance with Borg-Warner's recommendations. The rework'will be supervised and checked by Borg-Warner personnel.

Completion of the required rework will be determined when current labor negotiations are concluded and the necessary craft labor is available at the WNP-2 Site. The expected rework completion date will be provided as soon as conditions permit this determination to be made.

STAKE - 3 places approximately 120 0 apart A-A A A I

I RETAINER NUT SPLINED HUB I

I STEM NUT I

VALVE ASSEMBLY I INSERT NUT MOUNT FLANGE VALVE STEM FIGURE l.