Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
LICENSEE: ILLINOIS POWER CO.
SITE: CLINTON 1 EN NUMBER:32648
DOCKET: 05000461 EVENT DATE: 07-18-97
RX TYPE: BWR EVENT TIME: 12:00
VENDORS: GE-6 NOTIFY DATE: 07-18-97
EMERGENCY CLASS: N/A REGION: 3 STATE: IL TIME: 16:55
OPS OFFICER: DICK JOLLIFFE
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 COLD SHUTDOWN 0 COLD SHUTDOWN
-POSSIBLE 10CFR21 REPORTABLE CONDITION RE POTENTIAL DEGRADATION
OF RPS UPS-
GENERAL ELECTRIC SPECIFICATION #22A3153, REVISION 5, PARAGRAPH
4.3.5.6.3 REQUIRES THAT POWER BEING SUPPLIED BY REACTOR
PROTECTION SYSTEM (RPS) UNINTERRUPTIBLE POWER SUPPLY (UPS)
#103-1-189 BE DISCONNECTED IF AN ABNORMAL VOLTAGE OR FREQUENCY
CONDITION EXISTS FOR A DURATION OF 4 SECONDS OR MORE.
AN ENGINEERING INVESTIGATION CONDUCTED BY ELGAR CORPORATION, SAN
DIEGO, CA, AT CLINTON'S REQUEST, DETERMINED THAT WHILE THE
UNDER/OVER-FREQUENCY CIRCUIT CAN BE CALIBRATED TO MEET THE 4
SECOND DELAY THRESHOLD, THE UNDER/OVER-VOLTAGE DETECTION CIRCUIT
CANNOT MEET THIS SPECIFICATION DUE TO THE R-C TIME CONSTANT OF
THE OVER-VOLTAGE CIRCUIT INPUT FILTER COMPONENTS, WHICH BY
THEMSELVES, EXCEED THE 4 SECOND THRESHOLD AT CLINTON.
ELGAR CORPORATION RECOMMENDS THAT CLINTON EVALUATE THE TIMING
DELAY REQUIREMENTS APPLICABLE TO THE REACTOR PROTECTION SYSTEM TO
DETERMINE IF ACTUAL PERFORMANCE IS DEGRADED AND THAT CLINTON TAKE
ACTION AS APPROPRIATE. ELGAR CORPORATION IS PREPARED TO ASSIST IN
THIS EFFORT AT CLINTON'S REQUEST.
