ML20149K349

Final ASP Analysis - Hatch 1 (LER 320-80-069)

ML20149K349
Person / Time
Site:	Hatch
Issue date:	05/28/2020
From:	Christopher Hunter NRC/RES/DRA/PRB
To:
Littlejohn J (301) 415-0428
References
LER 1980-069-00
Download: ML20149K349 (4)

Text

Accession Number: 163478

July 10, 1980 e: HPCI and RCIC Fail to Inject Following Scram at Hatch I failure sequence was:

At 99.4% power, an erroneous reactor high water level signal initi-ated tripping of the feedwater pumps and the turbine/generator, which subsequently resulted in a reactor scram.

The reactor water level dropped to the low-low level set point.

The feedwater pump started but tripped since the MSIVs were closed.

On low low level the HPCI system received an auto-initiation signal but failed to inject water into the reactor due to automatic isolation of the HPCI turbine caused by the initial high steam pressure to the HPCI turbine.

RCIC was manually initiated during the event, but failed to start and remained inoperable throughout the event.

About 5 min after the event began, the operators cleared the HPCI steam supply isolation trip and HPCI auto-initiated successfully and injected water into the core.

ective action:

The HPCI isolation, due to steam line high pressure differential, was caused by the turbine speed controller being out of calibration. The system was recalibrated and HPCI tested satisfactorily.

The RCIC failure, determined to be due to a faulty limit switch and/or relay, was corrected by replacement of both components. The system was then tested satisfactorily.

Calibration surveillance and test procedures were being revised to include cold quickstarts of both HPCI and RCIC.

gn purpose of failed system or component:

RCIC provides RCS makeup following reactor trip or loss of water. HPCI provides cooling to the core given a small break LOCA.

follow- high steam AP due to a faulty us high due to an out- switch or relay al of-calibration turbine speed controller No No - ADS/

LPCI/CS operable No No No at Hatch 1 8 - Actual Occurrence of HPCI and RCIC Failure to Inject Following Scram

Control Adequate System Operates Adequate Core .Core Initiated Cooling Damage No 1 Yes 2 No 3 Yes 4 Yes S Yes 6 No 7 Yes 8 Yes 9 Yes 10 NSIC 163478 - Sequence of Interest forRCIC and HPCI Failure to Inject Following Scram at Hatch 1

C ACCESSION NUMBER: 163478 NO.: 80-069 E OF LER: July 10, 1980 E OF EVENT: June 26, 1980 TEM INVOLVED: HPCI and RCIC systems MPONENT INVOLVED: HPCI speed controller; RCIC trip switch and relay USE: Failed components, improper calibrating procedures UENCE OF INTEREST: Loss of feedwater UAL OCCURRENCE: HPCI and RCIC fail to inject following scram CTOR NAME: Hatch 1 KET NUMBER: 50-321 CTOR TYPE: BWR IGN ELECTRICAL RATING: 777 MWe CTOR AGE: 5.8 years DOR: General Electric CHITECT-ENGINEERS: Bechtel RATORS: Georgia Power Co.

CATION: 11 miles north of Baxley, Georgia RATION: N/A NT OPERATING CONDITION: Power not specified prior to scram E OF FAILURE: Failed to start COVERY METHOD: Operational event MENT: