Part 21 Report - 1997-020
LICENSEE: ABB-COMBUSTION ENGINEERING
SITE: ABB-COMBUSTION ENGINEERING EN NUMBER:31616
DOCKET: EVENT DATE: 12-06-96
RX TYPE: EVENT TIME: 12:00
VENDORS: NOTIFY DATE: 01-17-97
EMERGENCY CLASS: N/A REGION: 1 STATE: CT TIME: 16:15
OPS OFFICER: DICK JOLLIFFE
10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH
- ABB-CE 10CFR21 REPORT ON PIPING PRESSURE LOSSES BETWEEN SG AND
MSSVs -
ON 12/06/96, ABB-COMBUSTION ENGINEERING IDENTIFIED A DEFECT
CONCERNING THE PIPING PRESSURE LOSSES (i.e., DIFFERENTIAL
PRESSURE) BETWEEN THE STEAM GENERATOR (SG) AND THE MAIN STEAM
SAFETY VALVE (MSSV) INLETS WHEN THE MSSVs ARE ACTIVATED.
OMISSION OF THE SUBJECT PRESSURE LOSS FROM ANALYSES OF
OCCURRENCES DURING WHICH MSSVs ACTUATE COULD ADVERSELY AFFECT
THE
RESULTS OF CORRESPONDING LOCA AND NON-LOCA THERMAL HYDRAULIC
SAFETY ANALYSES,
MSSV PERFORMANCE, AND PIPING SYSTEM STRUCTURAL ANALYSES. THE
MAGNITUDE
OF THE PIPING PRESSURE LOSSES THAT ABB-CE HAS EXAMINED RANGES
FROM APPROXIMATELY 10 PSI TO MORE THAN 50 PSI.
ABB-CE DETERMINED THAT THIS OMISSION WAS APPLICABLE TO ALL SAFETY
ANALYSES DURING WHICH THE MSSVs ARE ACTIVATED FOR NUCLEAR POWER
PLANTS FOR WHICH ABB-CE WAS THE NUCLEAR STEAM SUPPLY SYSTEM
(NSSS) SUPPLIER.
ON 01/16/97, ABB-CE NOTIFIED EACH LICENSEE FOR WHICH IT WAS THE
NSSS SUPPLIER OF THIS ISSUE.
ABB-CE CONSIDERS THAT THIS ISSUE MAY BE APPLICABLE TO NUCLEAR
POWER PLANTS OTHER THAN THOSE FOR WHICH ABB-CE WAS THE NSSS
SUPPLIER.
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