ML20161A167

Final ASP Analysis - Turkey Point 4 (LER 251-81-011)

ML20161A167
Person / Time
Site:	Turkey Point
Issue date:	06/09/2020
From:	Christopher Hunter NRC/RES/DRA/PRB
To:
Littlejohn J (301) 415-0428
References
LER 1981-011-00
Download: ML20161A167 (4)

Text

IC Accession Number: 169587 te: November 4, 1981 e: Safety Injection Path to RCS Obstructed at Turkey Point 4 e failure sequence was:

. At the beginning of a refueling outage and while conducting a routine periodic test during partial draining of the RCS, the flow path to the RCS associated with the boron injection tank (BIT) was found obstructed.

The apparent cause of the obstruction was reduced temperature resulting from missing insulation in the vicinity of a 4-in. tee at the inlet to the BIT.

As a result of the obstruction, the safety injection flow path from all high head safety injection pumps to the RCS cold legs were blocked. A flow path to the hot legs was verified to be operable by establishing flow.

orrective action:

. The flow path was reestablished by alternating pump operation and raising the thermostat setting for the related heat tracing.

sign purpose of failed system or component:

The safety injection system provides high-pressure replacement ter to the RCS during a LOCA and steam line break. This system also ovides boron injection for steam break return to power considerations.

Severe Core Damage No - no requirement for safety injection No NSIC 169587 - Actual Occurrence for Safety Injection Path to RCS Obstructed at Turkey Point 4

LOCA Trip Feedwater and Pressure Recirculation Severe No.

Secondary Injection and LPR/HPI Core Heat Removal Cross-Connect Damage No I Yes 2 Yes 3 No 4 Yes 5 Yes 6 Yes 7 NSIC 169587 - Sequence of Interest for Safety Injection Path to RCS Obstructed at Turkey Point 4

ACCESSION NUMBER: 169587 NO.: 81-011 OF LER: November 4, 1981 OF EVENT: October 21, 1981 EM INVOLVED: Safety injection PONENT INVOLVED: 4-in. piping tee SE: Boric acid solidification blocked tee ENCE OF INTEREST: LOCA AL OCCURRENCE: Unavailability of high head safety injection paths TOR NAME: Turkey Point 4 KET NUMBER: 50-251 TOR TYPE: PWR GN ELECTRICAL RATING: 693 MWe TOR AGE: 8.4 years OR: Westinghouse HITECT-ENGINEERS: Bechtel ATORS: Florida Power & Light TION: 25 miles south of Miami, Florida ATION: 360 h (estimated)

T OPERATING CONDITION: Entering refueling shutdown OF FAILURE: Made inoperable OVERY METHOD: Testing ENT: