ML17306B278

Special Rept 3-SR-93-001:on 930204,reactor Trip Occurred & Main Feedwater Pump a Experienced Rapidly Decreasing Pump Speed.Valid Actuation of SI Actuation Sys & Containment Isolation Actuation Sys Also Occurred.Evaluation Underway

ML17306B278
Person / Time
Site:	Palo Verde
Issue date:	02/09/1993
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
192-00827-JML-T, 192-827-JML-T, 3-SR-93-001, 3-SR-93-1, NUDOCS 9302120200
Download: ML17306B278 (6)

Text

'CCELERATE DOCUIVIENT DISTRIBUTION SYSTEM (i'CCESSION NBR:9302120200 DOC.DATE: 93/02/09 NOTARIZED: NO DOCKET FACIL:STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530 AUTH. NAME AUTHOR AFFILIATION LEVINEEJ.M. Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk) 1

SUBJECT:

Special Rept 3-SR-93-001:on 930204,reactor trip occurred 6 main feedwater pump A experienced rapidly decreasing pump speed. Valid actuation of SI actuation sys & containment DISTRIBUTION CODE: IE22D NOTES:Standardized plant.

COPIES RECEIVED:LTR j isolation actuation sys also occurred. Evaluation underway.

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

SIZE:

05000530 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 TRAMMELLEC 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB10 1 1 NRR/DLPQ/LPEB10 1 1 ~

NRR/DOEA/OEAB 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB8H3 1 1

/@ST/+PLB8D1 1 1 NRR/DST/SRXB 8E 1 1 EG~ILM, 02 1 1 RES/DSIR/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL EG!EG BRYCE 9 J ~ H NRC PDR NSIC POORE,W.

1, 2

1 2

1 1

L ST LOBBY WARD NSIC MURPHYEG.A NUDOCS FULL TXT 1

1 1

1 1

1 NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 31 ENCL 31

Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O. BOX 52034 ~ PHOENIX, ARIZONA 85072.2034 JAMES M LEVINE 192-00827-JHL/TRB/KR VICE PRESIDENT NUCLEAR PRODUCTION February 9, 1993 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Mail Station P1-37 Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 3 Docket No. STN 50-530 (License No. NPF-74)

Special Report 3-SR-93-001 File: 93-020-404 Attached please find Special Report 3-SR-93-001, prepared and submitted pursuant to Emergency Plan Implementing Procedure (EPIP-03). This report discusses a condition requiring the declaration of a NOTIFICATION OF UNUSUAL EVENT due to an'event resulting in a Safety Injection Actuation System (SIAS) actuation, caused by a valid low pressurizer pressure. A copy of the Special Report is being forwarded to the Regional Administrator, NRC Region V.

If you have any questions, please contact T. R. Bradish, Manager, Nuclear Regulatory Affairs, at (602) 393-5421.

Sincerely, JML/TRB/KR Attachment cc: W. F. Conway (all with attachment)

J. B. Martin J. A. Sloan 9302120200 '930209 t 2<3.i 0 PDR ADOCK 05000530 8 PDR

PALO VERDE NUCLEAR GENERATING STATION UNIT 3 NOTIFICATION OF UNUSUAL EVENT Docket No. 50-530 License No. NPF-74 Special Report No. 3-SR-93-001 This Special Report is being provided pursuant to Emergency Plan Implementing Procedure (EPIP-03), "Notification of Unusual Event Implementing Actions" to report a condition requiring the declaration of a Notification of Unusual Event due to a Safety Injection Actuation System (SIAS) actuation, caused by a valid low pressurizer pressure for Palo Verde Unit 3 at approximately 1546 MST on February 4, 1993. The Notification of Unusual Event was terminated at approximately 1700 MST on February 4, 1993.

On February 4, 1993, at approximately 1523 MST, Palo Verde Unit 3 was in Mode 1 (POWER OPERATION) operating at approximately 100 percent power when a reactor trip occurred. Prior to the reactor trip, at approximately 1522 MST, the control board in Unit 3 indicated that Main Feedwater Pump (MFWP) A was experiencing a rapidly decreasing pump speed. Before Control Room personnel could respond to MFWP A's unstable operation by tripping MFWP A, the reactor tripped on low steam generator level for Steam Generator Number 2 (SG-2). Immediately following the reactor trip, a low steam generator level alarm came in for SG-1, followed by the actuation of both Auxiliary Feedwater Actuation Systems (AFAS-1 and AFAS-2) on low-low steam generator level for both steam generators. The Steam Bypass Control System responded as designed to control the secondary side pressure. The injection of auxiliary feedwater to the steam generators, combined with the quick-opening of the steam bypass control valves (SBCVs), caused reactor coolant system temperature to decrease which resulted in a pressure decrease below the low pressurizer pressure setpoint of 1837 psia. A valid actuation of the Safety Injection Actuation System (SIAS) and the Containment Isolation Actuation System (CIAS) occurred due to low pressurizer pressure. The Emergency Plan Implementing Procedures require the declaration of a Notification of Unusual Event (NUE) for an event resulting in Safety Injection Actuation System (SIAS) actuations, caused by a valid low pressurizer pressure. By approximately 1546 MST, on February 4, 1993, the appropriate state and local agencies were notified of the condition requiring the declaration of a Notification of Unusual Event (i.e., event resulting in SIAS actuations). The Nuclear Regulatory Commission (NRC) Operations Center was notified at approximately 1550 MST on February 4, 1993.

NRC Document Control Desk Special Report 3-SR-93-001 Page 2 At approximately 1551 MST, Control Room personnel commenced to shutdown Trains A and B Containment Spray pumps, High Pressure Safety Injection pumps, and Low Pressure Safety Injection pumps. Unit 3 was stabilized in Mode 3 (HOT STANDBY).

The Shift Supervisor diagnosed the event as an uncomplicated reactor trip.

At approximately 1700 MST on February 4, 1993, the Notification of Unusual Event was terminated in accordance with EPIP-03. By approximately 1709 MST on February 4, 1993, the appropriate state and local agencies and the NRC Operations Center were notified of the termination of the Notification of Unusual Event. By approximately 1811 MST, the SIAS, CIAS, AFAS-1, and AFAS-2 were reset.

Further investigation into the circumstances surrounding this event is being performed in accordance with the PVNGS Incident Investigation Program. The results of the investigation will be reported pursuant to 10CFR50.73.