ML17289A799

Part 21 Rept Re Limitorque Failure to Use Grade 5 Housing Cap to motor-operator Housing,Per Generic Ltr 89-10. Initially Reported on 920730.Seven GL 89-10 Category Valves Could Have Failed Due to Condition

ML17289A799
Person / Time
Site:	Columbia
Issue date:	08/13/1992
From:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-92 GL-89-10, GO2-92-193, NUDOCS 9208190209
Download: ML17289A799 (6)

Text

A'CCELERATED DISTRIBUTION DEMON'RATION SYSTEM REGULAlMY INFORNATIGN DISTR IBUTIG SYSTEM (R IDS)

ACCESSION 'NBR: '7208190209 DOC. DATE: 'V2/08/13 NOTARX ZED: NO DOCKET 0 FACIL: 50-397 MPPSB Nuclear Prospect> Unit 2> Mashington Public Poee 05000397 AUTH. NAME AUTHOR AFFXLXATXON BORENSENi G. C. Mashington Public Poeer Supply System RECXP. MANE RECIPIENT *FF I LXAT ION Document Control Branch (Document Control Desk)

SUBJECT:

Part 21 rept re Limitorque failure to use Grade 5 housing cap 'to motor -operator hous ing i per Gener ic Ltr 8'P-10.

Initially reported on 9'20730. Seven GL 8'7-10 category valves could have failed due to condition.

DISTRIBUTION CODE: XE19D COPIES RECEIVED'TR ( ENCL ~ SIZE:

TITLE: Part 21 Rept (50 DKT)

NOTES:

REC PI IENT CGP IES RECIPIENT CGP IES ID CODE/NANE LTTR ENCL ID CODE/MANE LTTR ENCL PD5 LA PD5 PD DEANi M.

INTERNAL: *EOD/DSP/ROAB 1 GCB11 NRR/DRIB/RVIB9D 1 EG F 01 REB/DSIR/EXB 1 RGN1 RGN2 1 RGN3 RGN4 1 RGN5 SECY VANDERNEL EXTERNAL: INPG RECORD CTR NRC PDR NSIC SILVERs E A

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK.

ROOM Pl-37 ( XT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUNBER OF CGP IES REQUIRED: LTTR c

18 ENCL

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Bec968 ~ 3000 George Wasbtngton Way ~ RtcbEand, Wasbtngton 99352<968 ~ (509) 372-5MO August 13, 1992 G02-92-193 Docket No. 50-397 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subject:

WNP-2, OPERATING LICENSE NPF-21 10 CFR PART 21 REPORT MOTOR-OPERATOR CAP SCREWS This is a 10 CFR Part 21 report submitted in accordance with the requirements of 10 CFR 21.21. Verbal notification of this condition was made to NRC Operations on July 30, 1992. The information required is provided below.

Re uirement 1 Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.

Res onse 1 Limitorque Corporation P. 0. Box 11318 Lynchburg, VA 24506-1318 Re uirement 2 Nature of the defect or failure to comply and the Substantial Safety Hazard which is created or could be created by such defect or failure to comply.

Res onse 2 Seven of the Generic Letter 89-10 category Limitorque model SMB-000 motor-operators at WNP-2 were manufactured by Limitorque with Grade 1 or 2 screws used for attaching the housing cap to the motor-operator housing.

These screws should be Grade 5. Grade 1 or 2 screws, at the minimum 9208190209 9208i3 8, '-"'DR PDR; ADOCK,05000397

JS ~ ~

.";)'qg(lP,'4'

Page Two 10 CFR PART 21 REPORT MOTOR-OPERATOR CAP SCREWS published material yield strength, could fail in-service if the motor-operator were set at greater than 94% of the rated motor-operator thrust load. These motor-operators are installed in safety-related applications at WNP-2. Seven Generic Letter 89-10 category valves could have failed due to this condition. Thus, it could have represented a Substantial Safety Hazard.

The actual condition at WNP-2 was not safety significant. Two of the seven motor-operators were set at a thrust value which could cause in-service failure of the grade 1 or 2 bolts at the minimum material yield strength. However, testing of the actual material properties showed that the bolts were acceptable for the loads applied. In addition, these two valves are required to open but are not required to close to perform their safety function. The housing cap mounting screws are under load only in the closing direction of valve travel. The remaining SMB-000 motor-operators with grade 1 or 2 cap screws are set at a thrust value below 94%

of the rated load as measured with diagnostic equipment or as determined from design calculations. This condition did not affect valve operability at WNP-2 and is not reportable pursuant to the requirements of 10 CFR 50.72 or 10 CFR 50.73.

It should be noted that the use of grade 1 and 2 cap screws is not limited to the SMB-000 model of motor-operator. However, grade 1 or 2 cap screws in other Limitorque models used at WNP-2 do not represent a Substantial Safety Hazard since they would not fail in-service at 100% of rated motor-operator thrust load.

Re uirement 3 The date on which the information of such defect or failure to comply was obtained.

Res onse 3 June 10, 1992.

4 In the case of a basic component which contains a defect or fails to comply, the number and location of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulations of this part.

Res onse 4 The Supply System does not possess this information. WNP-2 was the purchaser, not the supplier of these parts.

Page Three 10,CFR PART 21 REPORT

'MOTOR-OPERATOR CAP SCREWS Re uirement 5 The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action.

Res onse 5 For the Generic Letter 89-10 category motor-operators, the grade 1 and 2 cap screws which could have been subjected to potential in-service failure have been replaced with the proper grade of cap screw.

Re uirement 6 Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees.

Res onse 6 The Supply System has never experienced an in-service failure of these cap screws. Failure, if it were to occur, would generally occur during cap screw torquing.

Any questions concerning this report should be referred to Hr, D. A; Swank, Compliance Engineer, who can be reached at (509) 377-4451.

Sincerely, G. C. Sorensen, Nanager Regulatory Programs (Mail Drop 280)

DAS/bk cc: JB Hartin - NRC RV NS Reynolds - Winston 5 Strawn RR Assa - NRC DL Williams - BPA/399 NRC Site Inspector - 901A R Segan - Limitorque Corporation

0 4

\h

'~)4,