ML17312B621
| ML17312B621 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 08/01/1997 |
| From: | Ide W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 102-03987-WEI-A, 102-3987-WEI-A, NUDOCS 9708110081 | |
| Download: ML17312B621 (8) | |
Text
SUBJECT:
Responds to RAI related to risk-informed IST pilot program.
DISTRIBUTION CODE:
A047D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal: Inservice/Testing/Relief from ASME Code GL-89-04 T
05000528 05000529 05000530 NOTES:STANDARDIZED PLANT Standardized plant.
Standardized plant.
CATEGORY 1 REGULATO INFORMATION DISTRIBUTION TEM (RIDS)
ACCESSION NBR:9708110081 DOC.DATE: 97/08/01 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 Pu'bli 05000529 U STA-50=530 Palo Verde Nuclear Station, Unit 3, Arizona Publi'5000530 AUTH.NAME AUTHOR AFFILIATION IDE,W.E.
Arizona Public Service Co.
(formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
RECIPIENT ID CODE/NAME PD4-2 LA THOMAS,K INTERNAL: ACRS 1
ACT RES/DET/EIB EXTERNAL: LITCO ANDERSON NRC PDR COPIES LTTR ENCL RECIPIENT ID CODE/NAME PD4-2 PD AEOD/SPD/RAB NRR/DE/EMEB OGC/HDS2 RES/DET/EMMEB NOAC COPIES LTTR ENCL 1
1 1
1 D
0 C
E NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTEl CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN SD-5(EXT. 415-2083)
TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU'DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 14 ENCL
Jg Caemltment InervrtkNt.Ewe.
Palo Verde Nuclear Generating Station i William E. Ide Vice President Nuclear Engineering TEL 602/393-6116 FAX 602/3934077 Mad Station 7605 P.O. Box 52034 Phoenix, AZ 85072-2034 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555-0001 102-03987 - WEI/AKK/RKB August 1, 1997
References:
1.
Letter No. 102-03554, dated November 27, 1995, from W. L.
2.
Letter No. 102-03573, dated December 20, 1995, from W. L.
3.
Letter dated March 15, 1996, from C. R. Thomas, USNRC to W. L.
Stewart, APS.
4.
Letter No. 102-03714, dated June 7, 1996, from J. A. Bailey, APS to USNRC.
5.
Letter No. 102-03752, dated August 7, 1996, from W. L. Stewart, APS to USNRC.
6.
Letter No. 102-03763, dated August 23, 1996, from A. K. Krainik, APS to USNRC.
7.
Letter dated March 21, 1997, from J. W. Clifford, USNRC; to W. L.
Stewart, APS.
8.
Letter dated June 9, 1997, from J. W. Clifford, USNRC, to J. M.
Levine, APS.
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2, and 3 Docket Nos. STN 60-628/629/630 Response to Request for Additional Information Related To Risk-Informed Inservice Testing Pilot Program Arizona Public Service Company (APS) submitted a request (references 1 and 2) to the United States Nuclear Regulatory Commission (NRC) as part of a pilot plant effort related to risk-informed inservice testing (Rl-IST). In reference 3, the NRC staff 9708ii008i 97080~',T,.,
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, U.S. Nuclear Regulatory ommission ATTN: Document Control Desk Response to Request for Additional Information Related to Risk-Informed Inservice Testing Pilot Program Page 2 provided an initial request for additional information (RAI) to APS related to the Rl-IST pilot program.
A partial response to the initial RAI was provided by APS to the NRC staff via reference 4.
In reference 5, APS committed to provide the NRC staff with a revised schedule for fully responding to the initial RAI by September 15, 1996.
APS submitted additional information to the NRC staff related to the initial RAI in reference 6.
A second RAI was provided to APS by the NRC staff via reference 7.
In addition, the NRC staff and the pilot plants have held technical meetings on several occasions.
All of these activities have been in support of the development of a process for implementation of RI-IST.
On June 23, 1997, draft Regulatory Guides and Standard Review Plan sections were issued for public comment.
In reference 8, the NRC staff provided APS with advanced copies of the draft Regulatory Guides and Standard Review Plan sections along with a third RAI to provide comment on the draft documents and describe how APS'rogram comports to draft Regulatory Guides DG-1061, "General Guidance" and DG-1062, "IST." The staff asked for a response to this RAI or a plan and schedule for providing a complete response to the NRC within 45 days of receipt of this request.
Through the positive exchange which has developed with the NRC staff, it is believed that the development of the Rl-IST methodology has made significant gains.
The development of the Rl-IST methodology, however, involved more work than was initially anticipated.
While APS has up to now been focusing its resources on RI-IST, various other activities (e.g.,
the 10 year IST program update and improved technical specification implementation) now require the resources of Palo Verde IST personnel.
Unfortunately, the necessary resources must be diverted for a time from the implementation of Rl-IST in order to complete these other activities with a high level of quality. Once these activities have been completed, APS will resume implementation of RI-IST.
In addition, APS has learned through its work in the Rl-IST pilot program that although the Probabilistic Risk Assessment (PRA) model in use at Palo Verde is a high quality model, the software for solving the model is not agile enough for daily use in a production environment.
A typical solution of the PRA model takes approximately 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />.
This response time is unacceptable for daily configuration risk management.
For this reason, APS has chosen to replace its PRA software, the conversion of which will not be completed until mid-1998.
Since the software needed for implementation of Rl-IST is not currently operational at Palo Verde, limited value can be achieved in comparing APS'urrent program to the requested draft Regulatory Guides.
Jh
. -- U.S. Nuclear Regulatory ommission ATTN: Document Control Desk Response to Request for Additional Information Related to Risk-Informed Inservice
..- Testing Pilot Program Page 3 Therefore, due to the resource constraints and operational priorities discussed
- above, APS will not be in a position to resume supporting the Rl-IST implementation effort until mid-1998. At that time, APS will provide the NRC staff with a schedule for responding to the third RAI (reference 8).
APS believes that providing the NRC staff with a program comparison against draft Regulatory Guides DG-1061 and DG-1062 will adequately address the questions presented in the first and second RAls (references 3
and 6), and thus APS does not intend to provide any further specific correspondence regarding those RAls.
APS would appreciate feedback from the NRC staff if this approach to responding to the series of Rl-IST RAls is not acceptable.
APS will continue to support the development of Rl-IST methodology by providing review and comments on the Regulatory Guides and SRPs by the end of the 90 day period allowed for public comment, as well as through continued involvement with the ASME task group for component importance ranking.
APS has learned a great deal about risk informed applications as part of the pilot program and, believe this has contributed constructively to the integrated risk management process.
Should you have any questions, please contact Scott A. Bauer at (602) 393-5978.
Sincerely, WEI/AKK/RKB/mah cc:
E. W. Merschoff K. E. Perkins K. M. Thomas PVNGS Sr. Resident R. H. Wessman
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