PNO-V-89-014, on 890209,panel Annunciators Illuminated Before Startup Which Indicated Core Protection Calculators to Be Inoperable,But Crew Observed That Console Indications Were Normal.Licensee Investigation Still in Progress
| ML13302B697 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/09/1989 |
| From: | Huey R, Johnson P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| References | |
| PNO-V-89-014, PNO-V-89-14, NUDOCS 8902270254 | |
| Download: ML13302B697 (3) | |
ACCELERATE) 1D15fFh~bht7j U.N DEiMOM-:5II<AI.N t;Y T EM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:8902270254 DOC.DATE: 89/02/09 NOTARIZED: NO DOCKET #
FACIL:50-361 San Onofre Nuclear Station, Unit 2, Southern Californ 05000361 AUTH.NAME AUTHOR AFFILIATION JOHNSON,P.
Region 5, Ofc of the Director HUEY,R.
Region 5, Ofc of the Director RECIP.NAME RECIPIENT AFFILIATION IR
SUBJECT:
PNO-V-89-014:on 890209,reactor trip & unusual event during plant startup.
DISTRIBUTION CODE: IE34D COPIES RECEIVED:LTR 0 ENCL SIZE:
D TITLE: Preliminary Notification-Occurrence/Non-Routine Event/Saf guards Even NOTES:
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL A
INTERNAL: AEOD/DSP/TPAB 1
NRC OP CNTR 1
D NRR/DRIS/RVIB 1
NRR/DRIS/SGB 9A 1
NRR/DRIS/SIB 9A 1
NRR/PMAS/ILRB12 1
D NUDOCS=A-BSTRACT 1
OE LIEBERMAN,J 1
j ZF+/--LE 02 1
RES BROOKS,B 1
S RES DEPY 1
RES FILE 1
RES/DE 1
RES/DRA 1
RES/DSIR 1
RES/DSIR/EIB 1
RES/DSR DEPY 1
RES/PMPDAS 1
RGN5 FILE 01 1
EXTERNAL:
DOE BARBER EV34 1
LPDR 1
NRC PDR 1
NSIC 1
R I
S A
D D
NOTE TO ALL "RIES" RECIPIErTS:
S PIEASE HELP US TO REUCE WSTEI 0NTACT THE DOCMEqT OTR)L DESK, ROOM P1-37 (EXT. 20079) 'O ELIMNTE YOUR NAM FOM DISTRIBUIO LISTS FOR DOCUENS YOU DON'T NEE!
TOTAL NUMBER OF COPIES REQUIRED: LTTR
_2Mr ENCL 23
PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-89-14 Date 02/09/89 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information presented is as initially received without verification or evaluation and is basically all that is known by Region V staff on this date.
FACILITY: Southern California Edison Co.
Emergency Classification San Onofre Unit 2 X Notification of Unusual Event Docket No. 50-361 Alert Site Area Emergency General Emergency Not Applicable
SUBJECT:
REACTOR TRIP AND UNUSUAL EVENT DURING PLANT STARTUP A Unit 2 reactor startup was commenced at 4:05 a.m. PST on February 9, 1989.
Panel annunciators were illuminated before the startup which indicated the core protection calculators (CPCs) to be inoperable, but the operating crew observed that CPC console indications were normal and expected the annunciators to clear during the process of startup. Criticality was achieved at 4:45 a.m. After the reactor reached 1OE-4 percent power and the annunciators had not cleared, operators evaluated the CPCs further. They declared the CPCs inoperable at 5:00 a.m. and initiated a reactor shutdown. In their concern to shut down the reactor expeditiously, the operators failed to bypass the control element assembly calculators (CEACs, which provide rod position inputs to the CPCs) as is normally done at 1OE-4 percent power when shutting down. At 5:10 a.m. PST, shortly after the reactor was subcritical, a reactor trip signal was received from all four CPCs, caused by penalty factors generated by the CEACs (an expected result of control rod insertion, usually nullified by bypassing CEAC inputs to the CPCs). All control rods fully inserted, and other safety systems functioned as required.
Although the licensee's investigation is still in progress, preliminary results indicate that all four CPCs were operable throughout the event, but that the panel annunciators were not operating properly. The licensee reported at 10:30 a.m. PST that an Unusual Event had been belatedly declared as of 5:00 a.m. (due to shutdown required by the Technical Specifications) and terminated at 5:05 a.m. (when the unit entered Mode 3).
The licensee has notified state and local agencies that an Unusual Event was declared and terminated. The licensee does not plan to notify local news media at this time.
The resident inspectors are actively following the licensee's evaluation of this event.
Key concerns being explored by Region V include administrative control failures and the rationale of the operators which allowed the reactor startup to proceed with annunciators indicating the CPCs to be inoperable.
This information is current as of 11:00 a.m. PST on February 9, 1989.
Contact:
P. Johnson R. Huey (FTS) 463-3745 (714) 492-2641 0~
1.
DISTRIBUTION BY 5520:
FAX TO:
Date.1/c /4-Time l:ve 2r\\ PS'T Date Time Chairman Zech EDO RI INPO Comm. Roberts AEOD RH NSAC Comm. Carr PAO RIII LICENSEE Comm. Rogers SLITP RIV RESIDENT INSPECTOR Comm. Curtiss NRR HQS. OPERATIONS OFFICER SECY NMSS PDR (202)634-3343 ARM MAIL TO:
ACRS OIA DOT:(Trans. Only, Applicable State)
GPA RES CA RV FORM 211 Revised: 8/19/87