ML20168A572

Final ASP Analysis - Millstone 1 (LER 245-76-029)

ML20168A572
Person / Time
Site:	Millstone
Issue date:	06/16/2020
From:	Christopher Hunter NRC/RES/DRA/PRB
To:
Littlejohn J (301) 415-0428
References
LER 1976-029-00
Download: ML20168A572 (4)

Text

Gas Turbine Becomes Ino perable During Plant Trip at Millstone -1 re sequence was:

buildup on the 345 kv lines and insulators caused a loss of ite power.

gas turbine and diesel generator started, however, the gas turbine ed. It was restarted but again tripped after about 8 minutes.

stigation revealed that the-trips were due to improper alignment-e gas turbine generators auxiliaries.

e action:

urbine auxiliaries were aligned.

urpose of failed system or component:

power provides (a.c.) electric power when offsite power sources ilable.

ility of system per WASH 1400: Emergency power: 10-3 /D) ility of component per WASH 1400:1 vailabilities are in units of per demand D-1 . Failure rates are in per hour HRC'.,

No Yes, if shell side of IC cannot be resupplied No Yes, if shell side of IC cannot be resupplied

- Actual occurrence of Gas Turbine Becomes Inoperable During Plant Trip at Millstone 1

Manually Driven In I Cooling I Damage No 1 Yes 2 No 3 Yes 4

'Yes 5 No 6 Yes 7 Yes 8 No 9 Yes 10 No 11 Yes 12 Yes 13 Yes 14 Yes 15 116780 - Sequence of Interest of Gas Turbine Becomes Unavailable at Mlillstone 1

CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS CESSION NM-BER: 116780 LER: August 24, 1976 EVENT: August 10, 1976 INVOLVED: Electric Power T INVOLVED: Gas turbine, Transmission line.

Weather, maintenance OF INTEREST:

CCURRENCE: Gas Turbine Becomes Inoperable During Plant Trip.

NAME: Millstone 1 UMBER: 245 TYPE: BW LECTRICAL RATING: 660 Mwe ACE: 5.9 yr General Electric T-ENGINEERS: Ebasco S: North East Nuclear Energy Gompany

Five miles SW of New London

N/A ERATING CONDITION: Plant had just tripped.

EATURE TYPE OF FAILURE: (a) inadequate performance; (b) failed to start; (Doade inoperable; (d) ____________

Y METHOD: operational transient