ML17306B246

Comment Supporting in Part,Draft Reg Guide DG-1020, Monitoring Effectiveness of Maint at Npps.

ML17306B246
Person / Time
Site:	Palo Verde
Issue date:	01/15/1993
From:	Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION (ADM)
References
FRN-57FR55286, RTR-REGGD-1.160, RTR-REGGD-XX.XXX, TASK-DG-1020, TASK-RE 102-02394-WFC-T, 102-2394-WFC-T, 57FR55286, NUDOCS 9301280026
Download: ML17306B246 (8)

Text

REGULATO . INFORMATION DISTRIBUTION .STEM (RIDS)

~ i ACCESSION NBR:9301280026 DOC.DATE: 93/01/15 NOTARIZED: NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530 AUTH. NAME AUTHOR AFFILIATION CONWAYiW.F. Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION R Division of Freedom of Information S Publications Services I

SUBJECT:

Comment supporting in part, draft Reg Guide DG-1020, "Monitoring Effectiveness of Maint at NPPs."

DISTRIBUTION CODE: DS09D COPIES RECEIVED:LTR ENCL SIZE: S TITLE: SECY/DSB Dist: Public Comment on Proposed Rule (PR)-Misc Notice;Reg G NOTES:STANDARDIZED PLANT 05000528 F Standardized plant. 05000529 Standardized plant. 050005300 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL INTERNAL: OGC/rDR&5-B-18 1 1 OGC/SAIP15-B-18 1 1

~~G~5 RES/PMPDAS 01 1 1

1 1

RES DIR 1 1 EXTERNAL: NRC PDR 02 1 1 0

NOTE TO ALL RIDS" RECIPIENTS:

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

ROOM P 1-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED! A TOTAL NUMBER OF COPIES REQUIRED: LTTR 6 ENCL 6

~ I 7 4

Arizona Public Service Company P.O. BOX 53999 ~ PHOENIX. ARIZONA 85072-3999 102-02394-MFC/TRB/JNI WILLIAMF. CONWAY EXECUTIVEVICE PRESIDENT January 15, 1993 NUCLEAR Regulatory Publications Branch Division of Freedom of Information and Publications Services Office of Administration U. S. Nuclear Regulatory Commission Washington, DC 20555

Dear Sirs:

Cfl

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Comments on Draft Regulatory Guide DG-1020, "Monitoring the Effectiveness of Maintenance at Nuclear Power Plants,"

57 Fed. Reg. 55286 (November 24, 1992)

File: 93-057-026 The enclosure to this letter provides Arizona Public Service Company's comments on the draft Regulatory Guide DG-1020.

Should you have any questions regarding this information, please call Thomas R. Bradish at (602) 393-5421.

Sincerely, WFC/TRB/JNIfjnl Enclosure cc: J. B. Martin J. A. Sloan T. E. Tipton (NUMARC) 930i280026 930fi5; PDR REGGD XX. XXX C PDR

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ENCLOSURE COMMENTS ON DRAFT REGULATORY GUIDE DG-1020

k ENCLOSURE Arizona Public Service Company (APS) has reviewed the proposed Nuclear Management and Resources Council (NUMARC) comments regarding the four specific questions posed in the November 24, 1992, Federal Register notice (57 Fed. Reg. 55286) as well as Draft Regulatory Guide DG-1020, "Monitoring of the Effectiveness of Maintenance at Nuclear Power Plants." APS has also discussed with Baltimore Gas and Electric their comments on the same subject.

Upon completion of our review, APS endorses Baltimore Gas 8 Electric's comments and NUMARC's proposed comments with the following exceptions relating to NUMARC's comments.

Comment 18'Section: 9.3.1, 9.3.1.1, 9.3.1.2, Page: 14)

The use of a cumulative Risk Reduction calculation does not provide any additional insights. It is recommended that Section 9.3.1.1 only specify criteria for using the Risk Reduction Measure directly. The use of a cumulative Risk Reduction will result in increased costs associated with implementing the Maintenance Rule, with no substantial benefit to be gained from monitoring many of these Structures, Systems, and Components (SSCs).

Given that the large uncertainties associated with a calculated Core Damage Frequency and individual failure probabilities, the benefit to be gained from increased attention and maintenance activities would only be cost effective for those SSCs that have a substantial Risk Reduction Value. It is, therefore, recommended that Section 9.3.1.1 be revised to consider an SSC as Risk Significant if has an individual Risk Reduction Worth of greater than 1.05 (5%). Use of this criteria will allow utilities to focus their efforts on those SSCs that will provide a substantial benefit in terms of plant and public safety.

Comment: 6'nd 7'Figure 1)

Comment: 19'nd 20'Section: 9.3.2, Page: 15)

There is no need to impose specific performance criteria on Non Risk Significant SSCs.

Other sections of NUIVIARC 93-01 currently address actions to be taken if Maintenance Preventable Functional Failures occur on Non-Risk Significant SSCs. This avoids the additional cost (without substantial benefit) associated with setting and monitoring performance criteria for Non-Risk Significant SSCs.

M94ARC comments regarding recommended clarifications of NVMARC93-01, Revision 2A, July 9, 1992, Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, Resulting From V%V Program Implementation and Industrial Reviews.