ML20149K347
| ML20149K347 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 05/28/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1980-004-3L | |
| Download: ML20149K347 (4) | |
Text
SIC Accession Number: 154451 ate: February 12, 1980 itle: Inadvertent Opening of PORV at Haddam Neck he failure sequence was:
- 1. With the reactor at full power, spurious signal to the PORV and its isolation block valve was initiated in Pressurizer Pressure Control Channel 1.
- 2. Both valves opened and the RCS depressurized to 1992 psig.
- 3. The PORV and its associated block valve were remote-manually closed within approximately 10 seconds of the start of the transient. RCS pressure was restored to greater than 2000 psig within 2 minutes, terminating the transient.
orrective action:
Investigation and testing did not reveal the source of the roblem. The channel and valve controls were placed in the normal perating mode.
esign purpose of failed system or component:
PORVs are designed to prevent challenges to the main safety valves nd to assist in control of RCS pressure.
Damage No No - small-break LOCA mitigation capability prevents core damage No 154451 - Actual Occurrence for Inadvertent Opening of PORV at Haddam Neck
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 45 Yes 5 Yes 6 Yes 7 NSIC 154451 - Sequence of Interest for Inadvertent Opening of PORV at Haddam Neck
ACCESSION NUMBER: 154451 NO.: 80-04/3L E OF LER: February 12, 1980 E OF EVENT: February 4, 1980 EM INVOLVED: Pressurizer relief system PONENT INVOLVED: PORV and block valve SE: Spurious actuation signal UENCE OF INTEREST: Small break LOCA UAL OCCURRENCE: Inadvertent opening of a PORV and block valve CTOR NAME: Haddam Neck KET NUMBER: 50-213 CTOR TYPE: PWR IGN ELECTRICAL RATING: 580 MWe CTOR AGE: 12.5 years DOR: Westinghouse HITECT-ENGINEERS: Stone and Webster RATORS: Connecticut Yankee Atomic Power Co.
ATION: 13 miles east of Meriden, Connecticut ATION: N/A T OPERATING CONDITION: Full power OF FAILURE: Inadequate performance; inadvertent operation OVERY METHOD: Operational event MENT: Actuation logic for the PORV and block valve has been modified from a one channel pressure signal to a 2 out of 3 channels to prevent spurious actuations.