ML17310B430
| ML17310B430 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 07/12/1994 |
| From: | Stewart W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 102-03035-WLS-R, 102-3035-WLS-R, NUDOCS 9407200081 | |
| Download: ML17310B430 (15) | |
Text
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR 9407200081 DOC.DATE: 94/07/12 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, ilnit 3, Arizona Publi 05000530 F
AUTH.NAME AUTHOR AFFILIATION STEWART,W.L.
Arizona Public Service Co.
(formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Provides current status of Station Blackout Alternate AC Modifications.
DISTRIBUTION CODE:
A050D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal: Station Blackout (USI A-44) 10CFR50.63, MPA A-22 0
NOTES:STANDARDIZED PLANT Standardized plant.
Standardized plant.
RECIPIENT ID CODE/NAME PDIV-3 PD TRAN,L INTERNAL: ACRS NRR/DE/EELB NRR/DSSA SPLB
~ILE 01 EXTERNAL'RC PDR COPIES LTTR ENCL 1
1 1
1 1
1 3
3 1
1 1
1 RECIPIENT ID CODE/NAME HOLIAN, B AEOD/DSP/TPAB NRR/DRPE/PDII-4 NRR/DSSA/SRXB NSIC COPIES LTTR ENCL 1
1 1
1 1
1 1
1 1
1 05000528 05000529 05000530 T
D C
U N
NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACTTHE DOCUMENTCONTROL DESK, ROOM Pl-37 (EXT. 504-2083 ) TO ELIMINATEYOUR NAMEFROM DISTRIBUTIONLISTS I'OR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 14 ENCL 14
Arizona Public Service Company P.O. BOX 53999
~
PHOENIX, ARIZONA85072<999 WILLIAML. STEWART EXECU1IVEVICEPREEIDENT NUCLEAR U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555 102-03035-WLS/RAB/JNI July 12, 1994
References:
1) 2)
3)
Letter 102-02798-WFC/RAB/JNI dated January 25, 1994, from W. F. Conway, APS, to NRC, "Current Status of Station Blackout (SBO) Alternate AC Modifications" Letter dated April 14, 1993, from C. M. Trammell, NRC, to W. F. Conway, APS, "Station Blackout Final Supplemental Safety Evaluation - Palo Verde Nuclear Generating Station (TAC Nos. M68579, M68580, and M68581)"
Letter 161-04146-WFC/MEP dated August 31, 1991, from W. F. Conway, APS, to NRC, "Revised Response to the Station Blackout Rule (10 CFR 50.63)"
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Current Status of Station Blackout (SBO)
Alternate AC Modifications File: 94-001-419 94-056-026 As requested in Reference 2, Arizona Public Service Company (APS) is reporting the status ofthe Station Blackout (SBO) Alternate AC (AAC)standby gas turbine generators.
Attachment 1 describes the PVNGS status.
During the NRC SBO Inspection (IR 94-201), conducted from February 28 through March 4, 1994, PVNGS clarified the AAC Reliability Program methodology to the,NRC inspectors. describes this clariTication.
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'II40720008i 9407i2 PDR ADDCK 05000528 P
~ U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Current Status of SBO AAC Modifications Page 2 Should you have any questions, please contact Richard A. Bernier at (602) 393-5882; Since ely, WLS/RAB/JNl/rv Attachments:
1.
SBO Modification Status 2.
Clarification of SBO Reliability Program cc:
L; J. Callan K. E. Perkins K. E. Johnston B. E. Holian
ATTACHMENT1 PVNGS SBO MODIFICATIONSTATUS
Il l
SBO MODIFICATIONSTATUS Com letion of Unit 3 Alternate AC Modifications:
As requested in Reference 2, Arizona Public Service Company (APS) is reporting that the installation and testing of the Station Blackout (SBO) Alternate AC (AAC) sources standby gas turbine generators have been completed, including the connection of these generators to the Unit 3 electrical bus.
The connection to Unit 1 was reported in Reference 1.
The. Unit 2 modifications and testing will be completed during its next refueling outage, currently scheduled for April 1995.
APS willcommunicate the completion of Unit 2 Alternate AC modifications as requested by Reference 2.
Page 1 of 1
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ATTACHMENT2 PVNGS CLARIFICATIONOF SBO RELIABILITYPROGRAM
iI
CLARIFICATIONOF SBO RELIABILITYPROGRAM Discussion of AAC Reliabilit The following discussion clarifies the methodology used to verify AAC reliability.
In the attachment to Reference 3, page 9, item 13, under Capacity and Reliability, APS stated:
"The alternate AC power system, comprised of two standby Gas Turbine Generators, will meet or exceed a system reliability of 0.95 per demand as determined by NSAC-108."
In the attachment to Reference 3, page. 26, item 21, APS indicated:
PVNGS AAC will meet the requirements of NUMARC 87-00 section B.13(a) and RG 1.155 section 3.3.5.5.
NUMARC 87-00, Revision 1, page B4, section B.13(a), Systems Not Normally Operated (Standby-Systems),
states: "System reliability should be maintained at or above.95 per demand, as determined in accordance with NSAC-108 methodology (or equivalent)."
RG 1.155, August 1988, section 3.3.5.5 states:
"The reliability of the AAC power system should meet or exceed 95 percent as determined in accordance with NSAC-108 or equivalent methodology."
APS uses an equivalent methodology. The methodology utilizes samples of GTG test and operating data and compares this data with predetermined values (trigger values) to determine a proper course of action to support GTG reliability goals.
This methodology consists of four parts:
1.
Maintaining data on successful and failed GTG demands.
2.
Evaluating. the reliability indicators for the last 20, 26, 33, and 39 demands.
3.
Relating the calculated GTG reliability.indicators to trigger values established for the selected target reliability.
4.
Taking remedial actions for individual failures exceeding one or more trigger values.
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~ During the NRC SBO Inspection (IR 94-201), conducted from February 28 through March 4, 1994, PVNGS clarified the AAC Reliability Program methodology to the NRC inspectors.
The NRC issued Inspection Report 50-528/94-201, 50-529/94-201, and 50-530/94-201, Palo Verde Nuclear Generating Station, Units 1, 2, and 3, Station Blackout Inspection, dated April 13, 1994.
Quoting from Section 4.3.2 Alternate AC Source, page 8 of the report:
"The team concluded that the gas turbine generator system reliability program was similar to the EDG reliability program, included trigger values, and was adequate."
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