ML18101A462

LER 94-018-00:on 941209,safeguards Equipment Cabinet (Sec) 1A Declared Inoperable Due to Sequencing Problem & TS 3.0.3 Entered.Root Cause Analysis Will Be Performed.Rept Also Intended to Satisfy Requirements of 10CFR21.W/950104 Ltr

ML18101A462
Person / Time
Site:	Salem
Issue date:	01/04/1995
From:	PASTVA M J, SUMMERS J C Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-95 LER-94-018-01, LER-94-18-1, NUDOCS 9501130115
Download: ML18101A462 (8)

Text

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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 4icensee Event Report is being submitted pursuant to the requirements of Code of Federal Regulations 10CFR50. 73 (a) (2) (i) (B) and lOCFRSO. 73 (a) (2) (v) (D).

• Issuance of this report is required within thirty (30) days of event discovery.

MJPJ:vs C Distribution LER File "'! r'!! .. "' """ .. .. . 9501130115 950104 PDR ADOCK 05000272 S PDR The PO\\er is in your hands. Sincerely, J. C. Summers General Manager -Salem Operations 95-2189 REV 7-92 NRC FORM 366 . NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), u_s_ NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF (See reverse for required number of digits/characters for each block) MANAGEMENT AND BUDGET, WASHINGTON, DC 20503_ FACILITY NAME (1) DOCKET NUMBER (2) PAGE (3) Salem Generating Station -Unit 1 05000272 1 OF 6 TITLE (4) vesir,n Basis Concern Uue to lnoperability of lA Sa eguards Equipment Cabinet , SEC -

oad Sequencer) and Subsequent TS 3.0.3 Entry Due to Inoperability of lA and lB .J EVENT DATE {51 LEA NUMBER (6 REPORT NUMBER {7\ OTHER FACILITIES INVOLVED {8 SEQUENTIAL REVISION FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR MONTH DAY YEAR 05000 NUMBER NUMBER FACILITY NAME DOCKET NUMBER 12 09 94 94 --18 --00 01 04 95 05000 OPERATING 1 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: * (Check one or more {11 MODE (9) 20.402(b) 20.405(c)

50. 73 (a)(2)(iv) 73.71(b) POWER 100% 20.405(a)(1)(i) 50.36{c)(1) 50.73(a)(2)(v) 73.71{c) LEVEL (10) 20.405 (a)(1 )(ii) 50.36(c)(2) 50.73(a)(2)(vii)

OTHER -20.405(a)(1

)(iii) K 50.73{a)(2)(i) 50.73{a)(2){viii)(A) (Specify in Abstract below and in Texl, NRG 20.405{a)

{1) (iv) be 50.73{a)(2)(ii) 50.73(a)(2)(viii)(B)

Form 366A) 20.405{a)(1

)(v) 50.73{a)(2)(iii)

50. 73{a){2){x)

LICENSEE CONTACT FOR THIS LEA 121 NAME TELEPHONE NUMBER (Include Area Code) Michael J. Pastva, Jr.' LER Coordinator 609 339-5165 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER TO NPRDS TO NPRDS x JE xxxx Vl32 N SUPPLEMENTAL REPORT EXPECTED 14) EXPECTED MONTH DAY YEAR I YES SUBMISSION (If yes, complete EXPECTED SUBMISSION DATE) NO DATE (15) ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16) At 0914 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.47777e-4 months <br /> on 12/9/94, lA Safeguards Equipment Cabinet (SEC) was declared inoperable due to a sequencing problem and Technical Specification (TS) required action was entered. While troubleshooting the lA SEC problem, lB SEC was inadvertently rendered inoperable, TS 3.0.3 was entered and, at 1328 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.05304e-4 months <br />, reactor power reduction was begun.* At 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br />, 1B SEC was restored to operable and TS 3.0.3 was exited. At 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br />, lA SEC was restored to operable, TS required action was exited, and return to full power was begun. lB SEC inoperability is attributed to personnel error when the 1B SEC test panel was removed for installation in the lA SEC cabinet and the panel output relay test switch pushbutton A9 was inadvertently pushed and stuck in the depressed condition.

lA 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 mechanism(s) 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. NRG FORM 366 (5-92)

-BLOCK NUMBER 1 2 3 4 5 6 7 8 g 10 11 12 13 14 15 REQUIRED NUMBER OF DIGITS/CHARACTERS FOR EACH BLOCK NUMBER OF DIGITS/CHARACTERS TITLE UP TO 46 FACILITY NAME 8 TOTAL 3 IN ADDITION TO 05000 DOCKET NUMBER VARIES PAGE NUMBER UP TO 76 TITLE 6 TOTAL 2 PER BLOCK EVENT DATE 7 TOTAL 2 FOR YEAR 3 FOR SEQUENTIAL NUMBER LER NUMBER 2 FOR REVISION NUMBER 6 TOTAL 2 PER BLOCK REPORT DATE UP TO 18 --FACILITY NAME 8 TOTAL --DOCKET NUMBER OTHER FACILITIES INVOLVED 3 IN ADDITION TO 05000 1 OPERATING MODE 3 POWER LEVEL 1 CHECK BOX THAT APPLIES REQUIREMENTS OF 10 CFR UP TO 50 FOR NAME 14 FOR TELEPHONE LICENSEE CONT ACT CAUSE VARIES 2 FOR SYSTEM 4 FOR COMPONENT EACH COMPONENT FAILURE 4 FOR MANUFACTURER NPRDS VARIES 1 CHECK BOX THAT APPLIES SUPPLEMENTAL REPORT EXPECTED 6 TOTAL 2 PER BLOCK EXPECTED SUBMISSION DATE

.* :..* . .: . .i: :;;* LICENS.EVENT REPORT (LER) TE)CT' co;l'NuATION Salem Generating Station Unit# 1 Docket Number 50-272 Plant and System Identification:

LERNumber 94-018-00 Westinghouse

-Pressurized Water Reactor Page 2 of6 Energy Industry Identification System (EIIS) codes appear in the text as {xx} Identification of Occurrence:

Design Basis Concern Due To Inoperability Of lA Safeguards Equipment Cabinet (SEC -Emergency Load Sequencer)

And Subsequent . Technical Specification

3.0.3 Entry

Due To Inoperability of lA and lB 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 0.811 hours0.00939 days <br />0.225 hours <br />0.00134 weeks <br />3.085855e-4 months <br /> on December 9, 1994, monthly functional testing of lA Safeguards Equipment Control (SEC) System {JE} cabinet commenced, in accordance with procedure Sl.MD-FT.SEC-0001 (Q)

• Description of Occurrence:

At 0914 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.47777e-4 months <br /> on December 9, 1994, lA 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 lA SEC cabinet, lB SEC was inadvertently rendered inoperable and TS 3.0.3 was entered, at 1228 hours0.0142 days <br />0.341 hours <br />0.00203 weeks <br />4.67254e-4 months <br />. At 1328 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.05304e-4 months <br />, a reactor power reduction at 25%/hour was begun in accordance with TS 3.0.3. At 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br />, lB SEC was restored to operable and TS 3.0.3 was exited. At 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br />, lA SEC was restored to operable, TS required action LICENS.EVENT REPORT (LER) TEXT CO.ATION Salem Generating Station Unit# 1 Docket Number 50-272 Description of Occurrence: (cont'd) LERNumber 94-018-00 Page 3 of6 was exited, and the reactor power decrease was terminated at 52%. At 1348 hours0.0156 days <br />0.374 hours <br />0.00223 weeks <br />5.12914e-4 months <br /> (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 lA 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 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.97076e-4 months <br /> 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 lA SEC to be inoperable and required action, in accordance with TS Table 3.3-3, was entered. Troubleshooting identified that lA 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 for SEC operability.

While troubleshooting the lA SEC problem, the lA SEC test panel was replaced with the test panel from the lB SEC. Shortly thereafter, the lB 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

... It -----L-IC_E_N_S.EVENT REPORT .(LER) TEXT co1'11-Nu-AT_I_O_N

____ _ Salem Generating Station Unit# 1 Docket Number 50-272 Analysis of Occurrence:(cont'd)

LERNumber 94-018-00 Page 4 of6 the "Reset" position.

With the A9 switch pushbutton depressed lB 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 lB SEC while lA 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 lB SEC test panel, while already in a TS action statement due to the inoperability of the lA 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 lB SEC test panel. The cause of the lA 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 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 reqµirements applicable to a potential 10CFR21

" -----L-IC_E_N_S,EVENT REPORT (LER) TEXT coAuATION Salem Generating Station Unit# I Docket Number 50-272 Safety Significance: (cont'd) LERNumber 94-018-00 Page 5 of6 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 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 lB SEC) and C7 (in lA SEC) were exercised to ensure proper operation and were returned to service. Pushbuttons C7, in lA SEC, and A9, in lB 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 mechanism(s).

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*

• "

• LICENS.VENT REPORT (LER) TEXT CON.UATION Salem Generating Station Unit# 1 Docket Number 50-272 Corrective Action: (cont'd) LERNumber 94-018-00 Page 6 of6 pushbutton failure mechanism(s), appropriate action will be taken regarding other SEC pushbuttons on both Units. Individuals involved in the decision to remove the lB 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 rel_ay 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. MJPJ:vs * ., REF: SORC Mtg.95-001 J.a J. C. Summers General Manager -Salem Operations