Part 21 Report - 1995-043
ACCESSION #: 9501130115
LICENSEE EVENT REPORT (LER)
FACILITY NAME: Salem Generating Station - Unit 1 PAGE: 1 OF 6
DOCKET NUMBER: 05000272
TITLE: Design Basis Concern Due to Inoperability of 1A
Safeguards Equipment Cabinet (SEC - Emergency Load
Sequencer) and Subsequent TS 3.0.3 Entry Due to
Inoperability of 1A and 1B SECs
EVENT DATE: 12/09/94 LER #: 94-18-00 REPORT DATE: 01/04/95
OTHER FACILITIES INVOLVED: DOCKET NO: 05000
OPERATING MODE: 1 POWER LEVEL: 100%
THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR
SECTION:
50.73(a)(2)(i) & 50.73(a)(2)(ii)
LICENSEE CONTACT FOR THIS LER:
NAME: Michael J. Pastva, Jr., LER TELEPHONE: (609) 339-5165
Coordinator
COMPONENT FAILURE DESCRIPTION:
CAUSE: X SYSTEM: JE COMPONENT: XXXX MANUFACTURER: V132
REPORTABLE NPRDS: N
SUPPLEMENTAL REPORT EXPECTED: NO
ABSTRACT:
At 0914 hours on 12/9/94, 1A Safeguards Equipment Cabinet (SEC) was
declared inoperable due to a sequencing problem and Technical
Specification (TS) required action was entered. While troubleshooting
the 1A SEC problem, 1B SEC was inadvertently rendered inoperable, TS
3.0.3 was entered and, at 1328 hours, reactor power reduction was begun.
At 1530 hours, 1B SEC was restored to operable and TS 3.0.3 was exited.
At 1700 hours, 1A SEC was restored to operable, TS required action was
exited, and return to full power was begun. 1B SEC inoperability is
attributed to personnel error when the 1B SEC test panel was removed for
installation in the 1A SEC cabinet and the panel output relay test switch
pushbutton A9 was inadvertently pushed and stuck in the depressed
condition. 1A SEC inoperability is attributed to sticking of pushbutton
C7 during surveillance testing on 11/23/94. Pushbuttons A9 and C7 were
exercised and returned to service and will be replaced during the
upcoming Unit refueling outage. A root cause analysis will be performed
to determine, if possible, the involved pushbutton failure mechanisms)
and appropriate action will be taken on both Units. Procedure revisions
will be implemented to require verification that SEC output test relay
pushbuttons are not stuck following operation of the SEC output test
relay pushbuttons. These procedure revisions will also include a
requirement to run the Automatic Test Insertion (ATI) circuit through one
complete test cycle prior to aligning the ATI in its final configuration
and closing the SEC cabinet door. This report is also intended to
satisfy reporting requirements applicable to a potential 10CFR21 concern.
END OF ABSTRACT
ATTACHMENT TO 9501130115 PAGE 1 OF 2
Table "REQUIRED NUMBER OF DIGITS/CHARACTERS FOR EACH BLOCK" omitted.
TEXT PAGE 2 OF 6
Plant and System Identification:
Westinghouse - Pressurized Water Reactor
Energy Industry Identification System (EIIS) codes appear in the text as
{xx}
Identification of Occurrence:
Design Basis Concern Due To Inoperability Of 1A Safeguards Equipment
Cabinet (SEC - Emergency Load Sequencer) And Subsequent Technical
Specification 3.0.3 Entry Due To Inoperability of 1A and 1B SECs
Event Date: December 9, 1994
Report Date: January 4, 1995
This report was initiated by Incident Report No. 94-482
Conditions Prior to Occurrence:
Mode 1 Reactor Power 100% Unit Load 1158 MWe
At 0811 hours on December 9, 1994, monthly functional testing of 1A
Safeguards Equipment Control (SEC) System {JE} cabinet commenced, in
accordance with procedure S1.MD-FT.SEC-0001(Q).
Description of Occurrence:
At 0914 hours on December 9, 1994, 1A SEC cabinet was declared inoperable
and the required Technical Specification (TS) action was entered. This
occurred during the ongoing functional testing which revealed a
sequencing problem due to containment spray permissive relay XK72 being
unexpectedly energized. While troubleshooting the problem with the 1A
SEC cabinet, 1B SEC was inadvertently rendered inoperable and TS 3.0.3
was entered, at 1228 hours. At 1328 hours, a reactor power reduction at
25%/hour was begun in accordance with TS 3.0.3. At 1530 hours, 1B SEC
was restored to operable and TS 3.0.3 was exited. At 1700 hours, 1A SEC
was restored to operable, TS required action
TEXT PAGE 3 OF 6
Description of Occurrence: (cont'd)
was exited, and the reactor power decrease was terminated at 52%.
At 1348 hours (same day), the NRC was notified of the TS 3.0.3 entry
pursuant to the requirements of 10CFR50.72(b)(i)(A).
Follow-up investigation determined that inoperability of 1A SECs' output
relay XK72 existed from November 23, 1994 until event discovery and could
have resulted in exceeding required response time for initiation of
Containment Spray for a Loss of Coolant Accident (LOCA) with Loss of
Offsite Power. As such, at 1832 hours on December 16, 1994, the NRC was
notified of this determination, pursuant to the requirements of
10CFR50.72(b)(2)(iii).
Analysis of Occurrence:
Functional testing revealed 1A SEC to be inoperable and required action,
in accordance with TS Table 3.3-3, was entered. Troubleshooting
identified that 1A SEC relay XK72 was energized due to the relay output
test switch pushbutton C7 being stuck in the depressed position. This
caused the switch contacts to remain in the closed state, which would
have caused a delay in automatic initiation of containment spray if it
was required to actuate. The C7 push-button was exercised several times
and it was verified that the contacts reopened. The SEC cabinet is
provided with an online tester, identified as the Automatic Test
Insertion (ATI) circuit, which is not required to be in service for SEC
operability.
While troubleshooting the 1A SEC problem, the 1A SEC test panel was
replaced with the test panel from the 1B SEC. Shortly thereafter, the 1B
SEC ATI circuitry detected a fault and went into alarm. It was
determined the cabinet was inoperable and TS 3.0.3 was entered. The
fault condition was caused by sticking of relay output test switch
pushbutton A9 in the depressed position. During troubleshooting to clear
this alarm, ATI was reset, which caused output relay XK42 to energize,
per design, and resulted in tripping of 12 Reactor Nozzle Support Fan.
The output test pushbuttons are enabled when the ATI toggle switch is
placed in
TEXT PAGE 4 OF 6
Analysis of Occurrence:(cont'd)
the "Reset" position. With the A9 switch pushbutton depressed 1B SEC
would have performed all mode OP functions, with exception of sequencing
the 12 Reactor Nozzle Support Fan during a loss of offsite power event.
Failure of the fan to load would result in receiving a Sequence Failure
Alarm, alerting the Control Operator of this failure.
Apparent Cause of Occurrence:
The cause of the TS 3.0.3 entry (inoperability of 1B SEC while 1A SEC was
inoperable) is attributed to "Personnel Error", as classified by
NUREG-1022, Appendix B. This occurred due to poor judgment and
consequence thinking involved with the decision to remove the 1B SEC test
panel, while already in a TS action statement due to the inoperability of
the 1A SEC cabinet. This decision was based upon less than adequate risk
assessment prior to performing the evolution. A contributor was the
failure of A9 pushbutton in the depressed condition during removal of the
1B SEC test panel.
The cause of the 1A SEC inoperability is attributed to "Other", as
classified NUREG-1022, Appendix B, due to equipment malfunction of the C7
pushbutton. This most likely occurred when the C7 pushbutton became
stuck after intentional operation on November 23, 1994, during Solid
State Protection System (SSPS) surveillance testing. The investigation
was unable to identify any activities since the subject SSPS testing that
could have resulted in operation of the C7 pushbutton.
Prior Similar Occurrence:
Review of documentation did not reveal a prior similar occurrence.
Safety Significance:
This event did not affect the health and safety of the public. It is
reportable pursuant to 10CFR50.73(a)(2)(i)(B) and 10CFR50.73
(a)(2)(ii)(B). In addition, this report is intended to satisfy reporting
requirements applicable to a potential 10CFR21
TEXT PAGE 5 OF 6
Safety Significance: (cont'd)
concern involving the C7 and A9 pushbuttons, both Vitro Corp., Part
Number 8N1021C.
With the C7 pushbutton contacts stuck in the closed position, an increase
in the start time for Containment Spray initiation would have resulted.
Safety analyses affected by an increase in the start time are for
containment peak pressure, and temperature and dose analyses for LOCAs
and steamline breaks. The maximum increase in the start time (21
seconds) was conservatively assumed to bound the consequences of the
fault, which equates to an overall 18 second delay (both trains) in
containment spray delivery beyond that assumed in the existing safety
analysis. With this delay in containment spray delivery, sensitivity
analyses, performed by the NSSS vendor, for peak pressure and temperature
show containment pressure would increase by .18 psi and containment
temperature by < 0.2 degrees Fahrenheit. Increases on this order
represent minimal safety significance. The effect of this delay on
iodine removal is minimal since the amount of iodine that would have been
removed during the assumed 18 second delay for both trains, is not
expected to significantly contribute to a possible offsite dose.
Additional credit can be taken for conservatisms in various parameters,
such as containment spray temperature and temperature of Delaware River
water (cooling water for the Containment Fan Coil Units), where the
assumed values for these parameters are maximized to bound expected peaks
in summer temperatures. As such, potential consequences during this
occurrence would have been minimized as a result of the seasonal river
water temperatures, in the range of 40 to 50 degrees Fahrenheit.
Corrective Action:
Output Relay Test Switch pushbuttons A9 (in 1B SEC) and C7 (in 1A SEC)
were exercised to ensure proper operation and were returned to service.
Pushbuttons C7, in 1A SEC, and A9, in 1B SEC, will be replaced during the
upcoming Unit refueling outage and a root cause analysis of the removed
pushbuttons will be performed to determine, if possible, the involved
failure mechanisms). This timeframe for replacing the switches is based
upon a determination of limited potential safety gain from replacing the
pushbuttons at power. Following determination of the involved
TEXT PAGE 6 OF 6
Corrective Action: (cont'd)
pushbutton failure mechanisms, appropriate action will be taken regarding
other SEC pushbuttons on both Units.
Individuals involved in the decision to remove the 1B SEC test panel have
received the proper level of positive discipline, regarding their use of
poor judgment and consequence thinking.
Appropriate procedure revisions will be implemented to require
verification that SEC output test relay pushbuttons are not stuck
following operation of the SEC output test relay pushbuttons. As an
additional barrier, these procedure revisions will also include a
requirement to run the ATI through one complete test cycle prior to
aligning the ATI in its final configuration and closing the SEC cabinet
door.
J. C. Summers
General Manager -
Salem Operations
MJPJ:vs
REF: SORC Mtg. 95-001
ATTACHMENT TO 9501130115 PAGE 2 OF 2
PSE&G
Public Service Electric and Gas Company
P.O. Box 236 Hancocks Bridge, New Jersey 08038
Salem Generating Station
January 4, 1995
U. S. Nuclear Regulatory Commission
Document Control Desk
Washington, DC 20555
Attn: Document Control Desk
SALEM GENERATING STATION
LICENSE NO. DPR-70
DOCKET NO. 50-272
UNIT NO. 1
LICENSEE EVENT REPORT NO. 94-018-00
This Licensee Event Report is being submitted pursuant to the
requirements of Code of Federal Regulations 10CFR50.73(a)(2)(i)(B) and
10CFR50.73(a)(2)(v)(D). Issuance of this report is required within
thirty (30) days of event discovery.
Sincerely,
J. C. Summers
General Manager -
Salem Operations
MJPJ:vs
C Distribution
LER File
The power is in your hands.
95-2189 REV 7-92
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