Part 21 Report - 1998-330
LICENSEE: SIEMENS POWER CORP-NUCLEAR DIVISION
SITE: SIEMENS POWER CORP-NUCLEAR DIV EN NUMBER:34119
DOCKET: EVENT DATE: 04-21-98
RX TYPE: EVENT TIME: 12:00
VENDORS: NOTIFY DATE: 04-22-98
EMERGENCY CLASS: N/A REGION: 4 STATE: WA TIME: 12:40
OPS OFFICER: DICK JOLLIFFE
10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH
10 CFR PART 21 REPORT - NONCONSERVATIVE PREDICTION OF MONITORED
CORE MCPR -
SIEMENS POWER CORPORATION (SPC) PERSONNEL DETERMINED THAT
ADDITIVE CONSTANTS USED IN THE MINIMUM CRITICAL POWER RATIO
(MCPR) DETERMINATION FOR SIEMENS ATRIUM-9B FUEL BY THE CORE
MONITORING SYSTEM WERE FOUND TO BE NON-CONSERVATIVE (UP TO 7.6%
BASED ON THE ORIGINAL ADDITIVE CONSTANTS). IN ADDITION, SPC
PERSONNEL DETERMINED THAT THE UNCERTAINLY IN THE ADDITIVE
CONSTANT FOR THIS FUEL DESIGN WAS LARGER THAN PREVIOUSLY
ESTIMATED. THE REVISED UNCERTAINTY HAS THE POTENTIAL TO AFFECT
THE MCPR SAFETY LIMIT.
SPC PERSONNEL NOTIFIED ALL SPC CUSTOMERS WITH ATRIUM-9B LEAD TEST
ASSEMBLIES OR RELOAD QUANTITIES OF THE FUEL OF THE POSSIBLE
NONCONSERVATIVE PREDICTION OF THE MONITORED MCPR AT CONDITIONS
WHERE A SEVERELY UP-SKEWED AXIAL POWER SHAPE COULD OCCUR.
PLANTS AFFECTED ARE DRESDEN UNIT 3 (CYCLE 15), QUAD CITIES UNIT 2
(CYCLE 15), AND KUOSHENG UNITS 1 AND 2.
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