PNO-II-97-023A, on 970422,update to Unit 2 Shutdown Made,Due to Unidentified RCS Leakage Exceeding TS Limit of 1 Gpm.Nrc Resident Inspectors Observed Unit Shutdown & Will Continue to Followup on Licensee Recovery Activities
| ML15239A406 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/23/1997 |
| From: | Carroll R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| References | |
| FACA, PNO-II-97-023A, PNO-II-97-23A, NUDOCS 9704230252 | |
| Download: ML15239A406 (2) | |
CATEGORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9704230252 DOC.DATE: 97/04/23 NOTARIZED: NO DOCKET #
FACIL:50-270 Oconee Nuclear Station, Unit 2, Duke Power Co.
05000270 AOTH.NAME AUTHOR AFFILIATION CARROLL,R.
Region 2 (Post 820201)
RECIP.NAME RECIPIENT AFFILIATION
SUBJECT:
PNO-II-97-023A:on 970422,update to Unit 2 shutdown made,due to unidentified RCS leakage exceeding TS limit of 1 gpm.NRC resident inspectors observed unit shutdown & will continue to followup on licensee recovery activities.
DISTRIBUTION CODE: IE34F COPIES RECEIVED:LTR ENCL f SIZE:
TITLE: 50 Docket & Vendors PNO/Non-Routine Event/Safeguards Event (PN)
NOTES:
RECIPIENT COPIES RECIPIENT COPIES C
ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL C
INTERNAL: ACRS 1
1 NRR/DISP/PIPB 1
1 NUDOCS FULL TXT 1
OE DIR 1
RES/DET/EIB 1
RES/DRA 1
RES/DRA/DEPY 1
RES/DST 1
RES/DST DEPY 1
RES/RPHEB 1
RGN2 FILE 01 1
EXTERNAL: LITCO BRYCE,J H 1
NOAC 1
NRC PDR 1
C C
M E
N T
NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE.
TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR ENCL 16 April 23, 1997 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-97-023A This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by Region II staff in Atlanta, Georgia on this date.
Facility Licensee Emergency Classification Duke Power Co.
X Notification of Unusual Event Oconee 2 Alert Seneca,South.Carolina Site Area Emergency Dockets: 50-270 General Emergency Not Applicable
Subject:
EXTENDED SHUTDOWN -
OCONEE UNIT 2 (UPDATE)
This is an update to the April 22, 1997, Oconee Unit 2 shutdown due to unidentified reactor coolant system (RCS) leakage exceeding the Technical Specification limit of 1 gpm.
Upon shutdown of Unit 2 at 4:00 p.m., on April 22, 1997, a Notification of Unusual Event (NOUE) was declared when RCS pressure boundary leakage (approximately 12 gpm) exceeded the Emergency Action Level of 10 gpm. The NOUE was exited at 8:32 p.m. after two consecutive RCS leakage rates of less than 10 gpm, with the plant in a controlled depressurization/cool down, and no further evidence of plant condition degradation. A subsequent containment entry revealed an unisolable RCS leak emanating from a cracked weld in the area of the transition piece between the high pressure injection (HPI) line and the 2A1 reactor coolant loop nozzle.
The HPI piping upstream of the area of the leak was modified on all four RCS loops in Units 2 and 3 during earlier refueling outages.
Currently, Unit 2 RCS leakage is approximately 2 gpm. Preparations are underway to place the Low Pressure Injection/Residual Heat Removal system in service and take the unit to cold shutdown later today. The licensee has formed a Failure Investigation Team to determine root cause and evaluate operability of similar sections of HPI piping in all three units.
The NRC resident inspectors observed the unit shutdown and will continue to followup on the licensee's recovery activities.
The State of South Carolina has been notified. The licensee is prepared to respond to any media inquiries, but no press release is planned.
This information is current as of 9:00 a.m., on April 23, 1997.
Contact:
R. CARROLL (404) 331-5543 9704230252 970423 PDR I&E PNO-II-97-023A PDR