ML17291A543

Provides Update to Facility GL 89-10 MOV Program Status

ML17291A543
Person / Time
Site:	Columbia
Issue date:	12/09/1994
From:	Parrish J WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-10, GO2-94-275, NUDOCS 9412220098
Download: ML17291A543 (8)

Text

PRIDRI EY (ACCELERATED RIDS PROCI;SSIXG REGULATORY INFORMATION DISTRIBUTXON SYSTEM (RXDS)

ACCESSION NBR:.9412220098 DOC.DATE: 94/12/09 NOTARIZED: NO DOCKET FACIL:50-.39/ WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION PARRISH,J.V. Washington Public Power Supply System RECIP.NAME RECXPIENT AFFXLIATXON P Document Control Branch (Document Control Desk)

SUBJECT:

Informs that GL 89-10 6 suppls outline recommendations for R

testing 6 evaluating MOVs.

DISTRIBUTION CODE: A064D COPIES RECEIVED:LTR J ENCL ~ SIZE:

I TITLE: Response to Generic Ltr 89-10, "Safety-Related MOV Testing 6 Surveill NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD4-2 PD CLIFFORD,J INTERNAL: ACRS AEOD/SPD/RAB

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 Geotge Washington Way ~ Richland, Washington 993S2-0968 ~ (509) 372-SOOO December 9, 1994 G02-94-275 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 GENERIC LETTER 89-10 AND SUPPLEMENTS

Reference:

Letter GO2-93-217, dated August 31, 1993, JV Parrish (SS) to NRC, same subject Generic Letter (GL) 89-10 and its supplements outline the recommendations for testing and evaluating motor operated valves (MOVs), In the referenced letter, the Supply System committed to complete testing of the remaining GL 89-10 Program MOVs listed in Table 2 of the letter during the Spring 1995 (R-10) Maintenance and Refueling Outage. Included in the Table were 16 Main Steam Isolation Valve Leakage Control System (MSLC) valves, which had previously been baseline tested, but were scheduled to be retested using revised setpoints and a different testing methodology. Three of the valves have been retested, and the 13 remaining valves were to be retested during the R-10 outage.

Subsequent to submittal of the referenced letter, the Supply System decided to pursue a design change, similar to that implemented at Hatch 1 and 2, which will functionally deactivate the MSLC system. Subject to Technical Specification amendment submittal and NRC approval, the design change is planned for implementation during the Spring 1996 (R-11) Maintenance and Refueling Outage. As a result, the 13 MSLC MOVs scheduled to be retested during the R-10 outage are to be functionally deleted during the R-11 outage.

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jP Page 2 GENERIC-LETTER 89-10 AND SUPPLEMENTS V

It has been estimated that the Supply System would benefit from a one time savings of approximately $ 103,000 in refurbishment, engineering, and testing costs by not retesting the 13 MSLC MOVs during the R-10 outage. In addition, based on previous experience, not having to retest the valves could significantly reduce personnel radiation exposure and unplanned impacts on critical path outage work. Moreover, the Supply System can focus its resources on issues that are more beneficial to plant safety and reliability in the longer term. For the foregoing reasons, the Supply System does not intend to retest the remaining 13 MSLC MOVs from Table 2 of the referenced letter during the R-10 outage. However, normal MOV maintenance and inspections will continue to be performed. In the event that the MSLC system design change is not implemented as planned, the valves willbe retested during the R-11 outage.

In other words, retesting of the 13 MSLC MOVs will be essentially postponed by at most one year, at which time they will be either functionally deactivated or retested. This information is provided as an update to the WNP-2 MOV program status.

The Supply System has evaluated the effects of the postponement of retesting on the 13 MSLC MOVs involved and determined that there will be no impact on valve operability or functional reliability. The following discussion is provided in support of this conclusion.

The 16 MSLC MOVs listed in Table 2 of the referenced letter have been baseline tested in accordance with GL 89-10 guidance (circa 1992) using the ITI-MOVATS thrust measuring device (TMD) methodology. Subsequently, ITI-MOVATS (pursuant to 10 CFR 21.21(b)) and NRC Information Notice 92-23 notified the industry of concerns relating to the accuracy of the TMD methodology for MOV close stroke stem thrust measurements. The Supply System responded by re-evaluating the baseline test results for each MOV, including the MSLC MOVs, in accordance with the latest industry standards. In addition, the Supply System elected to reperform the baseline tests on the GL 89-10 Program MOVs where the TMD methodology had been used, regardless of the evaluation results. The retesting schedule was based on acceptability of the evaluations and the importance of the valve. Because of the generally acceptable evaluation results, 13 of the 16 MSLC MOVs listed in Table 2 of the Reference letter were scheduled for retesting during the R-10 outage, just prior to GL 89-10 Program close-out.

Because the accuracy of the TMD methodology is a concern for close stroke stem thrust measurements, the 16 MSLC MOVs listed in Table 2 of the Reference letter were evaluated for safety function and operability. Based on the evaluation, only four of the valves have a close safety function. As previously mentioned, three of the 16 MSLC MOVs have already been retested, and one of the four MOVs identified as having a close safety function was included in the valves that were retested. Since the retests incorporated the currently acceptable torque thrust cell and stem mounted strain gage methodologies for stem thrust measurement, only three MSLC MOVs have minimum required thrust baseline test data that could be affected by the measurement accuracy of the TMD methodology. The measured thrust data for the three MOVs were compared to the setpoint, which uses conservative assumptions for Rate of Loading, Stem Factor Degradation, and Valve Factor. In each case, sufficient thrust margin exists to assure

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Page 3 GENERIG LETTER 89-10 AND SUPPLEMENTS operability and functional reliability. Additionally, the thrust values and torque switch settings for the 13 MOVs to be retested were compared to those of the three MOVs retested using the torque thrust cell and stem mounted strain gage methodologies. In every case, the maximum measured thrust/torque values were below the design limits of the retested MOVs, and the torque switch settings were below the maximum allowed settings. Furthermore, since all 16 of the MSLC MOVs are limit open, the valves are not backseated and the open thrust design limits are not a concern.

The MSLC MOVs were identified as Graded Approach MOVs in the referenced letter. The MOVs classified as Graded Approach are considered to have conditions which do not require differential pressure testing to verify open/close capability. The criteria is applied to MOVs that are expected to have low maximum differential pressures, and a differential load less than the estimated packing load. Therefore, the effect of the differential pressure on the MOV is small and not significantly greater than static conditions.

Since the measured thrust values for the 16 MSLC MOVs listed in Table 2 of the referenced letter were found to provide sufficient thrust margin using the TMD methodology, further baseline retesting was not required. The Supply System had elected to reperform the baseline tests solely in an effort to update the test data to the latest industry standards prior to GL 89-10 Program close-out. There was no safety significance associated with the decision. Hence, the one year postponement of retesting willhave no impact on the operability or functional reliability of the 13 MSLC MOVs that remain to be retested.

Should you have any questions or desire additional information regarding this matter, please call me or D.A. Swank at (509) 377-4563.

Sincerely,

. V. Parrish (Mail Drop 1023)

Assistant Managing Director, Operations CD M/ml cc: LJ Callan - NRC RIV KE Perkins, Jr. - NRC RIV, Walnut Creek Field Office NS Reynolds - Winston & Strawn JW Clifford - NRC DL Williams - BPA/399 NRC Sr. Resident Inspector - 927N

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