Part 21 Report - 1998-010
ACCESSION #: 9712100072
Illinois Power Company
Clinton Power Station
P. O. Box 678
Clinton, IL 61727
ILLINOIS Tel 217 935-5623
POWER Fax 217 935-4632
An Illinova Company
John G. Cook
Senior Vice President
U-602876
4F.140
December 3, 1997
Docket No. 50-461 10CFR21.21
Document Control Desk
Nuclear Regulatory Commission
Washington, D. C. 20555
Subject: 10CFR21 Interim Report 21-97-044/047/048:
Deviations in Safety Related Battery Chargers
Dear Madam or Sir:
On September 29, 1997, the Division 2 safety-related battery charger
failed to operate as expected. Operators received an alarm in the Main
Control Room indicating low Division 2 DC bus voltage. Indications also
included 0 amps output from the Division 2 battery charger, and DC bus
voltage stabilized at about 128 VDC which is the expected voltage for a
loss of the battery charger. An electrician was dispatched to the
Division 2 battery charger to investigate the problem and noted that the
charger appeared to be stopping and starting itself "electronically"; the
DC voltage and output current decreased to 0 and then returned to normal.
The self starting and stopping of the charger occurred 4 times over
approximately a 30 minute period before the charger was secured for
troubleshooting.
On October 4, 1997, as a result of troubleshooting Illinois Power
(IP) identified inadequate soldered wire connections throughout the
battery charger. Specific examples include solder connections on the
Silicon Controlled Rectifier (SCR) firing circuit boards and on wiring
connections for the SCR firing circuit. This issue was determined to be
potentially reportable under 10CFR21; Condition Reports (CR) 1-97-10-090,
1-97-10-123, and 1-97-10-201 were initiated to track investigations and
resolutions of these issues.
On October 15, 1997, during further troubleshooting, IP noted 2
anomalies with the High Voltage Alarm (Shutdown) (DSHV) circuit card.
The time delay for the circuit card was approximately 6 seconds rather
than 30 seconds per the purchase specification, and the reset voltage
setpoint of the DSHV was too low to allow the DSHV circuit card to reset
during a momentary voltage transient while the battery charger was in the
equalize mode. This issue was determined to be potentially reportable
under 10CFR21; CR 1-9710-241 was initiated to track an investigation and
resolution of this issue.
U-602876
Page 2
In addition, during bench testing on October 15, 1997, a new DSHV
circuit card from stores failed to provide an output. The circuit card
was being tested prior to installation to determine its output response
time. During the testing, the trip setpoint voltage was reached and the
LED indication illuminated; however, the card failed to provide the
required output for the alarm and trip functions. This issue was
determined to be potentially reportable under 10CFR21; CR 1-97-10-249 was
initiated to track an investigation and resolution of this issue.
These conditions may also be applicable to the Divisions 1 and 4
safety-related battery chargers. The Divisions 1, 2, and 4 safety-
related battery chargers are Model 3SC-130-300, supplied by Power
Conversion Products, Inc. The DSHV reset voltage setpoint was provided
by Sargent & Lundy.
IP's evaluation of these conditions under 10CFR21 has not yet been
completed. IP does not have a firm date for resolving this issue but
will provide, as a minimum, an update on the resolution progress by
January 29, 1998.
Additional information about this issue may be obtained by
contacting M. D. Wagner, Plant Engineering, at (217) 935-8881,
extension 4071.
Sincerely yours,
J. G. Cook
Senior Vice President
RSF/krk
cc: NRC Clinton Licensing Project Manager
NRC Resident Office, V-690
Regional Administrator, Region III, USNRC
Illinois Department of Nuclear Safety
INPO Records Center
Power Conversion Products, Inc.
Sargent & Lundy
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