ML20168A571
| ML20168A571 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1976-012-00 | |
| Download: ML20168A571 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
112310 Date:
March 15, 19Ah
Title:
Gas Turbine Fails to-Achieve Rated Speed at Millstone 1 The failure sequence was:
- 1. The gas turbine was being tested daily since the isolation condensor (IC) was inoperable.
The feedwater coolant injection system, which is redundant to the IC, requires that the gas turbine be operable given a loss of offsite power.
- 2. During the surveillance test the gas turbine initiated that failed to reach rated speed.
Electronic components in the governor were malfunctioning.
- 3. The unit was placed in cold shutdown.
Corrective action:
The defective electronic components were replaced.
Design purpose of failed system or component:
- 1. The IC is a natural circulation heat sink used when the reactor is isolated.
- 2. The feedwater coolant injection systen provides a high pressure source of water given a snall LOCA.
Unavailability of system per WASH 1400: *IC:
N.A.
FWCI:
N.A.
Unavailability of component per WASH 1400:
Gas Turbine:
N.A.
Electronic components (solid state devices, low power application):
3.1 lOJHR Unavailabilities are In units of per demand D-1.
Failure rates are in units of per hour 11R1.
Daily Surveillance Of The Gas Turbine flue To IC Inoperability Gas Turbine Fails To Potential Reach Rated Speed Severe Core Damage No, no LOOP No NSIC 112310 -Actual Occurrence of Gas Turbine Fails to Achieve Rated Speed at Millstone 1
Loss of Of f site Power Reactor Diesel Scram Start ILoad Reactor Made Sub-and critical by the SBLCS Or Rods Are JManually Driven In RCIC/
Cl ADS/LPCI Long Initiate CS Term Initiate s Core Cooling J
Potent ial1 Severe Core Damage No Yes No Yes Yes No Yes Yes No Yes No Yes Yes Yes Yes Sequence No.
1 2
3 4
5 6
7 8
9 10 11 12 13 14 15 NSIC 112310 -
Sequence of Interest f or Gas Turbine Fails to Achieve Rated Speed at Millstone 1
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUNDER:
112310 DATE OF LER:
March 29, 1976 DATE (.F EVENT:
March 15, 1976 SYSTEM INVOLVED:
I.C., FWCI, Emergency Power.
COMPONENT INVOLVED:
Gas turbine CAUSE:
Failure of an electronic component SEQUENCE OF INTEREST: Loss of offsite power.
ACTUAL OCCUR~RENCE.
Gas Turbine Fails to Achieve Rated Speed.
REACTOR NAME: Millstone -
I DOCKET NUMBER:
245 REACTOR TYPE:
BW DESIGN ELECTRICAL RATING: 660 MWe REACTOR AGE: 54 yr VENDOR:
General Electric ARCHITECT-ENGINEERS: Ebasco.
OPERATORS:
Northeaistern Nuclear Energy Company LOCATION:
Five miles SW of New London DURATION:
12 (a) hours PLANT OPERATING CONDITION:
At Power.
SAFETY FEATURE TYPE OF FAILURE:
(a)inadequate performance; (b) failed to start; 01 made inoperable; (d) ____________
DISCOVERY METHOD: Surveillence testing.
COMMENT: