ML17313B075

LER 99-002-00:on 990730,test Mode Trip Bypass for EDG Output Breakers Not Surveilled.Cause Under Investigation.Operations Personnel Conservatively Invoked SR 3.0.3 for SR 3.8.1.13. with 990827 Ltr

ML17313B075
Person / Time
Site:	Palo Verde
Issue date:	08/27/1999
From:	Ide W, Marks D ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
192-01054-WEI-D, LER-99-002-01, NUDOCS 9909090236
Download: ML17313B075 (14)

Text

~ CATEGORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RXDS)

ACCESSION NBR:9909090236 DOC.DATE: 99/08/27 NOTARIZED'O DOCKET FACZL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 AUTH.NAME AUTHOR AFFILIATION MARKS,D.C. Arizona Public Service Co. (formerly Arizona Nuclear Power ZDE,W.E. Arizona Public Service Co. (formerly Arizona Nuclear RECIPIENT AFFZLZATION Power'ECIP.NAME

SUBJECT:

LER 99-002-00:on 990730,test mode trip bypass for EDG output C breakers not surveilled.Cause under investigation. Operations personnel conservatively invoked SR 3.0.3 for SR 3.8.1.13.

With 990827 ltr.

T.

DISTRIBUTION CODE: XE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES: STANDARDIZED PLANT 05000528@.

0)

RECXPIENT COPIES RECIPIENT COPIES C ZD CODE/NAME LTTR ENCL ZD CODE/NAME LTTR ENCL R LPD4-2 PD 1 1 FIELDS,M 1 1 Y,

INTERNAL! ACRS 1 1 L C 1 1 NRR/DXPM/XOLB 1 1 NRR/DRIP/RE 1 1 NRR/DSSA/SPLB 1 1 RES/DET/ERAB 1 1 RES/DRAA/OERAB 1 1 RGN4 FILE 01 1 1 EXTERNAL! L, ST LOBBY WARD 1 1 'MITCO MARSHALL 1 1 NOAC POORE,W. 1 1 NOAC QUEENER, DS 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 0"

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'E NOTE TO ALL RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE- TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE LISTS DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 FULL TEXT CONVERSZON REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 16 ENCL 16 c S Z P

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Witttam E. fde Mail Station 7602

'Palo Verde Nuclear Vice President TEL (623) 3936116 P.O. Box 52034 Generating Station Nuclear Production FAX (623) 393-6077 Phoenix, AZ 85072-2034 192-01054 WEIIDGM/RAS August 27, 1999 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units1,2, and 3 Docket Nos. STN 50-528/529/530 License Nos. NPFQ1/51/74 Licensee Event Report 99-002-00 Attached please find Licensee Event Report (LER) 50-528/99-002-00 prepared and submitted pursuant to 10 CFR 50.73. This LER reports a condition where emergency diesel generator output breaker relay trip bypasses were not surveilled in accordance with technical specification requirements. The corrective actions being taken as a result of this condition are being controlled in accordance with the PVNGS corrective action program..

There are no commitments made to the NRC by this letter.

In accordance with 10CFR50.73(d), a copy of this LER is being forwarded to the Regional Administrator, NRC Region IV and the Resident Inspector. If you have questions regarding this submittal, please contact Daniel G. Marks, Section Leader, Regulatory Affairs, at (623) 393-6492.

Sincerely, WE I/DGM/RAS Attachment cc: E. W. Merschoff (all with attachment)

J. H. Moorman N. Kalyanam INPO Records Ceps 9909090236 990827 PDR ADOCK 05000528 8 PDR

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NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 31Qh0104 EXPIRES 06/30/2001 (6-1996)

Estimated burden per response to comply with this mandatory Informaaon cogecaon request: 50 hrs. Reported tessons learned are ncorporated Into LICENSEE EVENT REPORT (LER) the licensing process and fed back to Indusby. Foward comments reganling burden estimate to the Records Management Branch fTW F33),

U.S. Nuclear Regulatory Commhske, Washington. Dc 205554001, and to (See reverse for required number of the Paperwork Reduction Prolect (31504104), Oface of Management and digits/characters for each block) Budget, Washington. DC 20503. If an Informatke collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person Is not required to respond to, the Informatke co section.

FACILITYNAME I1) DOCKET NUMBER (2) PAGE (3)

Palo Verde Nuclear Generating Station-Unit 1 05000528 1 OF 5 TITLE Ie)

Test Mode Trip Bypass for Emergency Diesel Generator Output Breakers Not Surveilled EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(8)

FACtLTTYNAME DOCKET NUMBER SEQUENTIAL REVISION MONTH DAY YEAR YEAR NUMBER NUMBER MONTH DAY YEAR PVNGS Unit 2 05000529 FACILITYNAME DOCKET NUMBER 07 30 1999 1999 - 002 - 00 08 27 1999 PVNGS Unit 3 05000530 OPERATING THIS REPORT IS SUBMITTED PURSUANT To THE REQ UIREMENTS OF 10 CFR: Check one or more 11 MODE (9) 20.2201 b 20.2203 a 2 v X 50.73 a 2 i 50.73 a 2 vlii POWER 20.2203 a 1 20.2203a 3 I 50.73 a 2 il 50.73 a 2 x LEVEL (10) 100 20.2203 a 2 i 20.2203 a 3 h 50.73a 2 Ir 73.71 20.2203 a 2 it 20.2203 a 4 50.73 a 2 iv OTHER 20.2203 a 2 Iit 50.36 c 1 50.73 a 2 v Specify In Abstract below or 20.2203 a 2 iv 50.36 c 2 50.73 a 2 vit in NRC Form 366A LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (tochde Area Code)

Daniel G. Marks, Section Leader, Nuclear Regulatory Affairs 623-393-6492 COMPLETE ONE UNE FOR EACH COMPONENT FAILURE DES CRIBED IN THIS REPORT 13 REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER TO EPIX TO EPIX SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED MONTH DAY YEAR YES SUBMISSION (If yes, complete EXPECTED SUBMISSION DATE). X NO DATE (15)

ABSTRACT (Limit to 1400 spaces, I.e., approximately 15 single-spaced typewritten lines) (16)

On July 30, 1999, at 1530 MST, Palo Verde Units 1, 2 and 3 were in Mode 1 (POWER OPERATION),

operating at approximately 100 percent power when operations personnel entered surveillance requirement (SR) 3.0.3. The SR 3.0.3 entry was based on an engineering assessment that concluded that surveillance test procedures did not verify that emergency diesel generator (EDG) output breaker test mode trips are bypassed during emergency mode of operation of the EDG. The engineering assessment identified that since April 1, 1996, the bypass function of these trips had been verified during testing performed under a maintenance procedure. Prior to April 1, 1996, testing of the EDG output breaker test mode bypass trips had not been performed.

A plant review board was convened to review the condition and after examining the six most recent performances of the maintenance testing results (two from each unit), it was determined that surveillance requirements had been met by the maintenance procedure. Prior to April 1, 1996 however, the bypass trips had not been tested in accordance with technical specification requirements. At approximately 1640 MST, on July 30, 1999, operations personnel exited SR 3.0.3 for the missed surveillances.

A revious similar event was reported in LER 50-528/97-006-00.

NRC FORM 366 (6-1996)

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NRO FoRM 866A (6-1998)

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET PAGE (3)

FACIUTY NAME (1) LER NUMBER (6)

NUMBER (2)

SEQUENTIAL REVISION NUMBER NUMBER Palo Verde Nuclear Generating Station Unit 1 '05000528 2 OF 5 1999 002 00 TEXT (lfmote spaceis fequited, use additional copies of NRC Form 366'17)

1. REPORTING REQUIREMENT(S):

This LER (50-528/99-002-00) is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B) to report an event that resulted in a condition prohibited by the plant's Technical Specifications (TS).

Specifically, prior to April 1, 1996, surveillance testing was not performed to verify that the emergency diesel generator (EDG)(EIIS: EK) output breaker (EIIS: EB, BKR) test mode trips are bypassed during emergency mode operation of the EDG. This surveillance requirement (SR) is currently contained in TS Limiting Condition for Operation (LCO) SR 3.8.1;13, which states: "Verify each DG automatic trip is bypassed on actual or simulated loss of voltage signal on the emergency bus concurrent. with an actual or simulated ESF actuation signal except: a. Engine overspeed; b.

Generator differential current; c. Engine low lube oil pressure; and d. Manual emergency stop. trip."

The TS SR in effect prior to April 1, 1996 were similar in wording to the current SR.

2. DESCRIPTION OF STRUCTURE(S), SYSTEM(S) AND COMPONENT(S):

This LER describes a condition where surveillance testing was not performed on contacts of the EDG output breaker control relay 4GEX2/15 (EIIS: RLY). The subject relays are Amerace Corporation, model number GPDR-C740, general purpose, normally deenergized, control relays.

The control circuits for the EDG 4160 volt output breakers include relays AX3 (EIIS RLY) and 4GEX2/15. Relay AX3 is energized by contacts from non-safety related generator protective relays and changes state during load unbalance, phase overcurrent, or neutral overvoltage conditions.

When any of-these conditions occur, contacts of relay AX3 close, providing a trip signal through the contacts of the 4GEX2/15 relay to the EDG output breaker. When the EDG is running in the "test mode," relay"4GEX2/15 does not change state (i.e., contacts closed) which allows signals from the AX3 relay contacts to trip the output breaker. Conversely, when the EDG is running in the "emergency mode," relay 4GEX2/15 changes state (i.e., contacts open) and trip signals generated-from the AX3 relay are bypassed.

3. INITIALPLANT CONDITIONS:

On July 30, 1999,.at approximately 1530 MST, Palo Verde Units 1, 2 and 3 were in Mode 1 (POWER OPERATION), operating at approximately 100 percent power. There were no structures, systems, or components that were inoperable that contributed to the event.

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NRC FORM 366A ie 1996)

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET

. FACILITYNAME (1) LER NUMBER (6) PAGE (3)

NUMBER (2)

SEQUENTIAL 'EVISION NUMBER NUMBER Palo Verde Nuclear Generating Station Unit 1 05000528 4 OF 5 1999 002 00 TEXT (Ilmore space is required, use adChih'onal copies of NRC Form 366hhhh) (17) related to those trips associated with the output'breakers. Since April, 1996, the bypass of the test mode trips for the EDG output breaker were considered important and were being periodically tested under a maintenance test but they were not considered to be within the scope of the TS SR.

Based on engineering review of industry reports relating to GL 96-01, the current interpretation of SR.3.8.1.13 should have included the output breaker trip bypasses as part of TS SR. The applicable surveillance test procedures (e.g., 73ST-1DG01, 73ST-2DG01 and 73ST-3DG01) for diesel generator and integrated safeguards surveillance testing will be revised to include the testing of the bypass function of the test mode trip initiating circuits for the EDG output breaker.

Since the testing of the EDG output breaker test mode trip was not identified in the APS original review of GL 96-01, the ongoing investigation will evaluate the adequacy of the initial review.

A supplement to this LER will be submitted following completion of the investigation if information is identified that would significantly change a reader's perception of the course or consequences of the event, or if there are substantial changes in the specified corrective actions.

7. CORRECTIVE ACTIONS AND ACTIONS TO PREVENT RECURRENCE:

Corrective actions:

On July 30, 1999, at 1530 MST, Operations, personnel in all three Palo Verde units conservatively invoked SR 3.0.3 for SR 3.8.1.13 to allow for completion. of the surveillance test within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The plant review board convened and examined the six most recent performances of the maintenance procedure (two from each unit) and determined the surveillance requirement had been met by the testing performed under the maintenance test procedure. At approximately 1640 MST, on July 30, 1999, unit operations personnel exited SR 3.0.3 for the missed EDG trip surveillances.

Actions to prevent recurrence:

The applicable surveillance test procedures (e.g., 73ST-1DG01, 73ST-2DG01 and 73ST-3DG01) for diesel generator and integrated safeguards surveillance testing will be revised to include the testing of the. bypass function of the test mode trip initiating circuits for the EDG output breaker. This action will be completed on a unit by unit basis before the next required surveillance performance for each unit.

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