ML17303A487

Special Rept SR-87-003:on 870613,diesel Generator a Tripped on Sensed Overspeed Condition.Caused by Separation of 2 Piece Connecting Cable at Coupling.Separated Cable Reconnected.Investigation Into Cause of Separation Ongoing

ML17303A487
Person / Time
Site:	Palo Verde
Issue date:	07/10/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00245-JGH-T, SR-87-003, NUDOCS 8707200579
Download: ML17303A487 (6)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR: 8707200579 DQC. DATE: 87/07/10 NOTARIZED: NO DOCKET ¹ FACIL: STN-50-530 Palo Verde Nuclear Stationi Unit 3i Arizona Publi 05000530 AUTH. NAME AUTHOR AFFILIATION HAYNES'. G. Arizona Nuclear Power Prospect (formerly Arizona Public Serv RECIP. NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

RO 87-003: on 870613'iesel generator trip occurred. Caused bg overspeed butterfly valve latch releasing overspeed butterfly valve +hen two-piece cable seperated at coupling.

Cables reconnec ted.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ENCL SIZE:

TITLE: 50. 73 Licensee Event Report (LER)> Incident Rpti etc.

NOTES: Standardized plant. M. Davis NRR: iCg. 05000530 REC I P IENT CQP IES RECIPIENT CQP IFS ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD LICITR*iE 1 DAVIS' 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 -2 AEOD/DOA 1 1 AEOD/DSP/ROAB 2 2 AEQD/DSP/TPAB 1 1 DEDRO 1. 1 NRR/DEST/ADE 1 0 NRR/DEST/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 NRR/DEST/ I CSB 1' 1 NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 NRR/DEST/PSB l.

NRR/DEST/RSB 1 NRR/DEST/SGB 1 1' NRR/DLPG/HFB 1 s

NRR/DLPG/GAB NRR/DOE*/EAB 1 1 NRR/DREP/RAB NRR/DREP/RPB NRR/PMAS/ ILRB NRR/PMAS/PTSB G 02 1 1 RES DEPY GI 1 1 i J 1 1 RES/DE/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL: EG8cG GRQHs M 5 5 H ST LOBBY NARD 1 LPDR 1 NRC PDR 1 1 NSIC HARRIS' 1 NSIC MAYST G 1 NOTES: 1 1 TOTAL NUMBER OF COP. IES REQUIRED: LTTR 46 ENCL 44

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Arizona Nuclear Power Project P.o. BOX 52034 ~ PHOENIX, ARIZONA85072-2034 192-00245-JGH-TRB/MJC July 10, 1987 U.S. Nuclear Regulatory Commission NRC Document Control Desk Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 3 Docket No. STN 5U-530 (License NPF-65)

Special Report SR-87-003 File: 87-020-404 Dea'r Sirs:

Attached'lease find a Special Report. SR-87-003 prepared and submitted pursuant to Technical Specifications 4.8.1.1.3 and 6.9.2. This report discusses a valid emergency diesel generator failure that occurred on June 13, 1987.

If you have any questions, please contact T. R. Bradish, Compliance Supervisor at (602) 393-5000, Ext. 6936.

Very tr ly yours, J. G. Haynes Vice President Nuclear Production JGH/TRB/MJC/cld Attachment cc: 0. M. DeMichele (all w/a)

E. E. Van Brunt, Jr.

J. B. Martin R. P. Zimmerman R. C. Sorenson E. A. Licitra A. C. Gehr INPO Records Center

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II Qi PALO VERDE NUCLEAR GENERATING STATION Valid Failure Experienced on Diesel Generator A Docket No. STN-530 License .No. NPF-65

. Special Report No. 3-SR-87-003 This Special Report is being submitted pursuant to Technical Specification (T.S.) 4.8.1.1.3 and T.S. 6.9.2 to report a valid diesel'enerator failure.

This report is written in accordance with Regulatory Position C.3.b of Regulatory Guide 1.108, Revision 1, August 1977.

At'pproximately 0226 MST on June 13, 1987, Palo Verde Unit 3 was in Mode 5 (COLD SHUTDOWN) when diesel generator "A" tripped on a sensed overspeed condition during the performance of the Emergency Diesel 'Generator "A" Start Surveillance Test (43ST-3DG01). Diesel Generator "A" was declared and'oad inoperable at 0226 and the appropriate T.S. A(TION Statements were complied with.

An investigation determined that an actual overspeed condition did not exist and that the diesel generator "A" trip occurred when the overspeed butterfly valve latch released the spring 'loaded overspeed butterfly valve. The valve latch released the overspeed butterfly valve when a two (2) piece connecting cable separated at a coupling. The connecting cable connects the overspeed, butterfly valve latch to the overspeed governor. As corrective action, the separated cable was reconnected. A root cause of failure investigation has been initiated to determine the cause of the connecting cable separation. As a prudent action work authorizing documents will be issued to inspect the connecting cables for the diesel generators in all three units.

Since the overspeed protection trip is not bypassed in the emergency operating mode, this is considered a valid failure. This was the first valid failure experienced on Palo Verde Unit 3 diesel generator "A". Therefore, pursuant to T.S. 4.8.1.1.2, Table 4.8-1, the test frequency will remain at one (1) test every 31 days.

At approximately 2250 MST on June 13, 1987, diesel generator "A" was declared operable following the successful completion of the Surveillance Test 43ST-3DGOl. Diesel Generator "A" was unavailable for 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> and 24 minutes.

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