ML051380367
| ML051380367 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 04/28/2005 |
| From: | Seaman C Arizona Public Service Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 102-05270-CKSITNW/JAP | |
| Download: ML051380367 (3) | |
Text
10 CFR 50.46 ZLA A
subsidiary of Pinnacle West Capital Corporation Craig K. Seaman Director.
RegulatoryAffairs Tel. 623-393-5421 Mail Station 7636 Palo Verde Nuclear Fax 623-393-5442 P.O. Box 52034 Generating Station CSeaman@apsc.com Phoenix, Arizona 85072-2034 102-05270-CKSITNW/JAP April 28, 2005 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2, and 3 Docket Nos. STN 50-52815291530 Emergency Core Cooling System (ECCS) Performance Evaluation Models, 10 CFR 50.46(a)(3)(ii) Annual Report For Calendar Year 2004 Pursuant to 10 CFR 50.46(a)(3)(ii), Arizona Public Service Company (APS) has enclosed the Westinghouse Electric Company's, "Annual Report on Combustion Engineering ECCS Performance Evaluation Models for PWRs, CENPD-279, Supplement 16, March 2005." This report describes the changes and errors in Combustion Engineering models for Pressurized Water Reactors (PWRs) ECCS performance analysis in calendar year 2004. Appendix A of this report is specific to PVNGS. All other appendices of this report are plant-specific to other Combustion Engineering (CE) designed facilities and have not been included as part of this submittal.
As shown in the table on page 3 of this letter, the PVNGS large break loss of coolant accident (LBLOCA) and small break loss of coolant accident (SBLOCA) analyses used the 1999 EM and S2M evaluation models, respectively, throughout calendar year (CY) 2004. As of December 31, 2004, there were no known changes or errors that affected the PVNGS PCT calculations performed with these evaluation models. Additionally, because PCT is not calculated as part of the post loss of coolant accident (LOCA) long-term cooling (LTC) analysis, there are no changes or errors in the LTC models that affect PCT.
A member of the STAIRS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- South Texas Project
- Wolf Creek
ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Emergency Core Cooling System (ECCS)
Performance Evaluation Models, 10 CFR 50.46(a)(3)(ii) Annual Report Page 2 No commitments are being made to the NRC by this letter.
If you have any questions, please contact Thomas N. Weber at (623) 393-5764.
Sincerely, CKS1TNW/JAP Enclosure cc:
B. S. Mallett NRC Region IV Regional Administrator M. B. Fields NRC NRR Project Manager for PVNGS G. G. Warnick NRC Senior Resident Inspector for PVNGS
ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Emergency Core Cooling System (ECCS)
Performance Evaluation Models, 10 CFR 50.46(a)(3)(ii) Annual Report Page 3 Summary of Cumulative Effects on Calculated Peak Clad Temperature (PCT) for PVNGS Due to Changes/Errors in ECCS Performance Evaluation Models Large Break LOCA Small Break LOCA PVNGS Operating Time Period Cumulative Cumulative Unit Cycle in 2004 Evaluation Calculated Effect of Evaluation Calculated Effect of Model PCT Changes/Errors Model PCT Changes/Errors on PCTV11 on PCTr1 1
11 January-April 1999 EM 21100F None"'
S2M 16180F None3')
1 12 May - December 1999 EM 21100F None"'
S2M 16180F None(J) 2 12 January-December 1999 EM 21100F None"2)
S2M 16180F None"'
3 11 January - November 1999 EM 21100F None"'
S2M 16180F None(3) 3 12 December 1999 EM 21100F None"'
S2M 16180F None 4' Notes:
- 1. Pursuant to 10 CFR 50.46(a)(3)(i), this is a cumulation of the absolute magnitudes of the respective changes in Peak Clad Temperature (PCT) for each known change to and/or error in the associated ECCS performance evaluation model.
- 2. Supplement 14 of CENPD-279 states that STRIKIN-I1 computer code errors were identified and corrected in CY 2002, involving a time step algorithm and the Coffman plastic strain model. The PVNGS 1999 EM LBLOCA analysis of record, however, utilized a corrected version of STRIKIN-Il. Therefore, these previously reported errors had no effect on calculated PCT for PVNGS. Additionally, Supplement 16 of CENPD-279 states that an Advanced Automated / Integrated Code System (AAICS) was implemented in CY 2004, to better automate data flow between computer codes and to ensure consistency of input between the codes. The PVNGS 1999 EM LBLOCA analysis of record, however, did not utilize the AAICS. Therefore, implementation of MICS had no effect on calculated PCT for PVNGS. There is no previous cumulative effect on PCT for the PVNGS 1999 EM LBLOCA analyses, nor are there any relevant changes or errors identified in CY 2004.
- 3. Supplement 13 of CENPD-279 states that a CEFLASH-4AS computer code error was identified and corrected in CY 2001, involving calculations of leak flow rate with out-of-range subscripts. The PVNGS S2M SBLOCA analyses, however, utilized a corrected version of CEFLASH-4AS. Therefore, this previously reported error had no effect on calculated PCT for PVNGS. There is no previous cumulative effect on PCT for the PVNGS S2M SBLOCA analyses, nor are there any relevant changes or errors identified in CY 2004.