ML17311A386
| ML17311A386 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 10/29/1994 |
| From: | James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 102-03165-JML-A, 102-3165-JML-A, TAC-M90581, NUDOCS 9411080134 | |
| Download: ML17311A386 (10) | |
Text
(ACCELERATED RIDS PROCESSING)
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR>9411080134 DOC.DATE: 94/10/29 NOTARIZED: NO DOCKET FACIL:STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 AUTH.NAME AUTHOR AFFILIATION LEVINE,J.M.
Arizona Public Service Co.
(formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Submits suppl info in support of mod of compensatory actions identified zn NRC ltr dtd 941013.
DISTRIBUTION CODE:
A001D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal:
General Distribution NOTES:Standardized plant.
05000529 RECIPIENT ID CODE/NAME PD4-2 LA HOLIAN, B INTERNAL: ACRS
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NRR/DE/EELB NRR/DRPW NRR/DS SA/SRXB OGC/HDS2 EXTERNAL NOAC COPIES LTTR ENCL 1
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1 6
6 1
1 1
1 1
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1 RECIPIENT ID CODE/NAME PD4-2 PD TRAN,L FILE CENTER 7D CH HICB NRR/DSSA/SPLB NUDOCS-ABSTRACT NRC PDR COPIES LTTR ENCL 1
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1 YOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE iVASTE!CONTACT'f!IE DOCL'XIEYTCONTROL DESK, ROOhf PI-37 IEXT. 504-2083 ) TO ELIlhfIYATEYOUR iAifE FROil DISfRI8UTION LISTS I:OR DOCL'MEi'I'SYOI'ON"I'EED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 20 ENCL 19
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Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O. BOX 52034
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PHOENIX, ARIZONA85072-2034 JAMES M. LEVINE VICE PAESIDENT NUCLEAR PRODUCTION U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555 102-03165-JML/AKK/DRL October 29, 1994 Dear Sirs;
Reference:
NRC Letter to W. Stewart, dated October 13, 1994, "Issuance of Emergency Amendment for the Palo Verde Nuclear Generating Station Unit No. 2 (TAC No. M90581)"
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Unit 2 Docket No. STN 50-529 Revision of Compensatory Actions for Battery Testing File: 94-056-026 94-005-419.05 Based upon a telephone conversation with NRC Staff on October 28, 1994, Arizona Public Service Company (APS) is providing the enclosed supplemental information in support of a modification of the Compensatory Actions identified in the referenced letter.
Should you have any questions, please contact Scott A. Bauer at (602) 393-5978.
Sincerely, JML/AKK/DRL/rv Enclosure cc:
L. J. Callan K. E. Perkins B. E. Holian K. E. Johnston A. V. Godwin (all w/enclosure)
(ARRA)
AA(lg2p 94ii080134 94i029 PDR ADOCK 05000529
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ENCLOSURE REVISION OF COMPENSATORY ACTIONS FOR BATTERY TESTING
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ENCLOSURE On October 13, 1994, Amendment No. 71 to Facility Operating License No. NPF-51 for the Palo Verde Nuclear Generating Station (PVNGS) was issued.
The safety evaluation for the amendment delineated the compensatory actions to be implemented while the amendment is in effect.
One of the defined Compensatory Actions was float current of the installed battery trains must be measured on one train each week and the value must be less than or equal to 500 ma or the batteries were to be declared inoperable.
Testing conducted during the week of October 24, 1994, has determined that accurate float current readings can not be taken on the installed battery trains in accordance with the identified Compensatory Action.
Due to the configuration of the safety-related 125VDC system at PVNGS, the float current reading taken on the installed batteries contains noise due to the battery chargers also supplying power to plant loads under normal operation.
The readings are taken using an existing shunt in the battery circuit and a digital volt meter.
The voltage value is then converted to amperage based on the known resistance value of the shunt.
The installed shunt is sized to read the much higher currents experienced during battery discharge rather than for taking float current readings.
As a result, the float current readings taken at the shunt are masked by noise of a magnitude equal to or greater than the float current such that an accurate reading can not be made.
Modifications to the installed instrumentation are not possible without removing the batteries from service.
Measurements were taken of float current in Units 1 and 3 and similar results were obtained.
Since the battery banks contain both degraded cells and new cells', the individual cell voltages of the new cells would increase if the degraded cells were drawing an increased float current.
This effect is experienced because all cells are connected in series and the new cells would experience the same increased float current as the degraded cells, thereby driving up their individual voltage.
Therefore, individual cell voltage of the new cells provides a'measure of the state of the degraded cells.
'New cells" refer to the twenty three new replacement cells and the combined eight spare cells from Units 1 and 3.
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7 Based upon.the above information, APS proposes to modify the identified Compensatory Actions for float voltage and float current as follows:
Parameter Actions to be Limits/Allowable Taken if Outside Limits Float Voltage All cells New cells
) 2.18 Volts
( 2.35 Volts Battery Inoperable Battery Inoperable Float Current Control cells Installed cells
( 500 ma
( 2 amps averaged value Battery Inoperable Battery Inoperable In addition, as agreed in a previous telephone conversation of October 26, 1994, the battery service test for the first control group has been rescheduled until the end of the first week of November to accomodate the arrival of additional testing equipment.
The second service test will be performed in late November in accordance with the NRC safety evaluation for the license amendment.
4 The control cells will consist of cells that have not been subjected to a battery service test.
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