Part 21 Report - 1997-180
LICENSEE: COMMONWEALTH EDISON CO.
SITE: BYRON 1 2 EN NUMBER:31890
DOCKET: 05000454 05000455 EVENT DATE: 03-03-97
RX TYPE: PWR PWR EVENT TIME: 00:00
VENDORS: W-4-LP W-4-LP NOTIFY DATE: 03-04-97
EMERGENCY CLASS: N/A REGION: 3 STATE: IL TIME: 16:22
OPS OFFICER: HENRY BAILEY
10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH
UNIT SCRAM RX INIT INITIAL MODE CURR CURRENT MODE
CODE CRIT PWR PWR
1 N N 0 HOT SHUTDOWN 0 HOT SHUTDOWN
2 N Y 100 POWER OPERATION 100 POWER OPERATION
10 CFR PART 21 NOTIFICATION - CRACKING OF VITEC TRANSFORMER CORES
THESE TRANSFORMERS ARE INSTALLED IN VARIOUS SAFETY-RELATED
CIRCUITS BOARDS. TEMPERATURE CHANGES IN THESE CIRCUIT BOARDS
COULD CAUSE ASSOCIATED INSTRUMENTATION TO DRIFT OUT OF RANGE.
THE SAFETY-RELATED APPLICATIONS WHERE THIS TRANSFORMER HAS THE
MOST POTENTIAL IMPACT ARE THE DELTA TEMPERATURE PROTECTION
FUNCTIONS (NRA CARDS) IN THE REACTOR PROTECTION SYSTEM (RPS).
THE DRIFT IN THE RPS COULD CAUSE A CHANNEL TO TRIP RESULTING IN A
LOSS OF REDUNDANCY IN THE DIVERSE TRIP FUNCTION.
NOTE: THIS ISSUE ALSO APPLIES TO BRAIDWOOD UNITS 1 AND 2 AND TO
ZION
UNITS 1 AND 2.
Page Last Reviewed/Updated Wednesday, March 24, 2021