ML18106A852

LER 98-011-00:on 980803,ESFA During a 4KV Automatic Transfer Test Was Noted.Caused by Premature Release of Control Console Pushbutton Due to Inadequate Procedural Step.Revised procedure.W/980827 Ltr

ML18106A852
Person / Time
Site:	Salem
Issue date:	08/27/1998
From:	Bakken A, Manges C Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-98-011-01, LER-98-11-1, LR-N980414, NUDOCS 9809040067
Download: ML18106A852 (5)

Text

OPS~G Public Service ~lectric ~nd Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit AUG 2 7 1998 LR-N980414 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

LICENSEE EVENT REPORT 98-011-00 SALEM GENERATING STATION - UNIT 2 FACILITY OPERATING LICENSE NO. DPR-75 DOCKET NO. 50-311 This Licensee Event Report entitled "Engineered Safety Features Actuation During A 4kV Automatic Transfer Test" is being submitted pursuant to the requirements of 10CFR50.73(a)(2)(iv).

Sincerely, a4&cG2--

A. C. Bakken Ill General Manager -

Salem Operations CEM I/,

c Distribution LER File Tht pm\*er is in \\)Ur !1mds.

95-2168 REV. 6/94

NRC FORM 366 U.S. NUCLEAR REGU RY COMMISSION APP D BY OMB NO. 3150-0104 EXPIRES 06/30/2001 (6-1998) Estimated burden per response to comply with this mandatory infonnation collection request: 50 hrs. Reported lessons learned are incorporated into LICENSEE EVENT REPORT (LER) the licensing process and fed back to industry. Forward comments regarding burden estimate to the Records Management Branch (T-6 F33),

U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, and (See reverse for required number of to the Paperwork Reduction Project (3150-0104), Office of Management .

and Budget, Washington, DC 20503. If an infonnation collection does not digits/characters for each block) display a currently valid OMB control number, the NRC may not conduct or sp?ns9r. and a person is not required to respond to, the infonnation FACILITY NAME (1) DOCKET NUMBER (2) PAGE (3)

SALEM GENERATING STATION UNIT 2 05000311 1 OF 4 TinEl4)

Engineered Safety Features Actuation During A 4KV Automatic Transfer Test EVENT DATE (5) LER NUMBER (6) REPORT DATE 171 OTHER FACILITIES INVOLVED (8) i ll-T=.-=-:....,..,~,.,-......,.,.""""',.......il-uy~EA~R.:-Tl---,,S~E~Q~U~EN~T~IA~L--,-.,,.IRE~v~1s~1~o~Nit-.M"'O~N~T~H,-,-~D~A~Y-r--Y-EA_R_,rF-A-Cl-LITY_N_A_M_E MONTH DAY YEAR _ _ _ _ _ _ _.,...-DO-C-K-ET-N-U-M-BE-R---~i NUMBER NUMBER 05000 08 3 98 98 011 - 00 08 27 98 FACILITY NAME DOCKET NUMBER 05000

---

.. 1- 5 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR ": (Check one or more) (11 I ODE (9) 20.2201 (b) 20.2203(a)(2)(v) 50. 73(a)(2)(i) 50. 73(a)(2)(viii) 0 20.2203(a)(1) 20.2203(a)(3)(i) 50. 73(a)(2)(ii) 50. 73(a)(2)(x)

(10) 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 50. 73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) )( 50. 73(a)(2)(iv) OTHER

,._-+-~~~~~~----+--i-:=-:~:=-=-::=!C!....:..!.-----+a....i~:..:.:,.;:::..!-=~!.!:..:-'-------hs,.-Jpecify in Abstract below 20.2203(a)(2)(iii) 50.36(c)( 1) 50. 73{a)(2)(v)

- - + - - - - - - - - - - - + - - - t - - - - - - - - - - t - - - ; r - - - - - - - - - - - - - - - i or in NRC Form 366A 20.2203(a)(2)(iv) 50.36(c)(2) 50. 73(a)(2)(vii)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Area Code)

C. Manges - Senior Licensing Engineer (609) 339-3234 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TO EPIX TO EPIX SUPPLEMENTAL REPORT t:XPECTED (14) EXPECTED MONTH DAY YEAR YES SUBMISSION I (If yes, complete EXPECTED SUBMISSION DATE).

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

At 2150 on August 3, 1998, while performing testing of the 2A 4KV Vital Bus as required by Technical Specification Surveillance Requirement 4.8.1.1.1.b, the 2A 4kV Vital Bus deenergized when the transfer from the 24 Station Power Transformer (SPT) to the 23 SPT failed. When the bus deenergized, the 2A Safeguards Equipment Control (SEC) generated an undervoltage signal for loss of its associated vital bus. The 2A SEC and its associated components functioned as designed, and all safety-related equipment responded as expected. The actuation of the SEC and the subsequent trip of the 21 CC pump is considered to be an Engineered Safety Feature (ESF) actuation and is reportable in accordance with 10CFR50. 73 (a) (2) (iv). A four-hour report was made on August 3, 1998 in accordance with the requirements of 10CFR50. 72 (b) (2) (ii). The cause of the ESF actuation was premature release of the control console pushbutton prior to ensuring that the control console breaker "close" light was illuminated due to an inadequate procedural step.

Corrective actions include revising the procedure.

NRC FORM 366 (6* 1998)

NRC FORM 366A (6-1998)

• U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET (2) LER NUMBER (6) PAGE (3)

NUMBER (2)

SALEM GENERATING STATION UNIT 2 05000311 YEAR I SEQUENTIAL NUMBER I REVISION NUMBER 2 OF 4 98 -- 011 -- 00 TEXT (If more space is required, use additional copies of NRG Form 366AJ (171 PLANT AND SYSTEM IDENTIFICATION Westinghouse - Pressurized Water Reactor Medium Voltage Power System, Class lE - EIIS Identifier {EB/---}*

• Energy Industry Identification System (EIIS) codes and component function identifier codes appear as {ss/ccc}.

IDENTIFICATION OF OCCURRENCE Event Date: August 3, 1998 CONDITIONS PRIOR TO OCCURRENCE Prior to the Engineering Safety Features (ESF) actuation, Salem Unit 2 was in Mode 5. The 2A 4kV Vital Bus was not operable and the 2A Emergency Diesel Generator (EOG) and the associated 460/230 Volt Motor Control Centers (MCCs) were out of service. Component loads associated with the 2A Vital Bus had been transferred as a result of the 2A bus not being operable. The only 2A 4kV Vital Bus load that was running at the time of the ESF actuation was 21 Component Cooling (CC) pump. The shutdown risk plan had addressed the contingencies with 2A 4kV Vital Bus not being operable.

DESCRIPTION OF OCCURRENCE At 2150 on August 3, 1998, while performing testing of the 2A 4KV Vital Bus as required by Technical Specification Surveillance Requirement 4.8.1.1.1.b, the 2A 4kV Vital Bus deenergized when the transfer from the 24 Station Power Transformer (SPT) to the 23 SPT failed. When the bus deenergized (as sensed by the 2A instantaneous 70% bus undervoltage relay and the 95.1% degraded voltage relays), the 2A Safeguards Equipment Control (SEC) generated an undervoltage signal for loss of its associated vital bus. This actuation signal generated component trip signals and tried to start the 2A EOG. The 21 CC pump was tripped by the actuation signal and 23 CC pump started on low CC header pressure. Several valves that would normally be closed by the SEC actuation did not reposition due to the 460/230 MCCs being out of service.

Since the 2A EOG was tagged out of service, the 2A EOG output breaker did not close and no load sequencing occurred. In summary, the 2A SEC and its associated components functioned as designed, and all safety-related equipment responded as expected.

NRC FORM 366A (6-1 998)

--, NRC FORM 366A (6-1998)

U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (lER)

TEXT CONTINUATION FACILITY NAME 111 DOCKET 121 LER NUMBER (6) PAGE 131 NUMBER 121 SALEM GENERATING STATION UNIT 2 05000311 YEAR I SEQUENTIAL NUMBER I REVISION NUMBER 3 OF 4 98 -- 011 -- 00 TEXT (If more space is required, use additional copies of NRG Form 366AJ (17)

Procedure S2.0P-ST.4KV-0001(Q), "Electric Power Systems 4KV Vital Bus Transfer", governs the bus transfer testing and directs the operator to press the control console 23ASD Breaker close pushbutton and to ensure that the control console 23 ASD Mimic Bus Interlock Close Selection light extinguishes. The operator performing the transfer recalled seeing the control console breaker "open" indicating light for 23ASD flashing. The operator did not expect this flashing light and prematurely released the infeed breaker pushbutton. Early release of the pushbutton resulted in failure of Infeed Breaker 23ASD to close and caused the 2A 4KV Vital Bus to de-energize.

The actuation of the SEC and the subsequent trip of the 21 CC pump is considered to be an Engineered Safety Feature (ESF) actuation and is reportable in accordance with 10CFR50. 73 (a) (2) (iv). A four-hour report was made on August 3, 1998 in accordance with the requirements of 10CFR50. 72 (b) (2) (ii).

CAUSE OF OCCURRENCE The cause of the ESF actuation was premature release of the control console pushbutton prior to ensuring that the control console breaker "close" light was illuminated. This error is attributed to an inadequate procedure step.

The procedure does not identify that the pushbutton must be pressed and held until the console breaker mimic "close" light illuminates or a SEC undervoltage safeguards actuation occurs. In addition, there is no information noting the possibility of a flashing console breaker "open" light for 23 ASD that could occur depending on the amount of time required for the bus to transfer.

PREVIOUS OCCURRENCES A review of LERs issued in the past two years at Salem and Hope ~reek Generating stations did not identify any similar occurrences regarding ESF actuations durihg bus transfer testing.

ASSESSMENT OF SAFETY CONSEQUENCES The actuation was the result of a procedural deficiency during testing. If an actual undervoltage had occurred during non-testing conditions, the system would have functioned as required. The consequences were limited to the unnecessary actuation of an ESF component. There were no actual consequences and no impact on public health or safety.

NRC FORM 366A (6-1998)

NRC FORM 366A (6-1998)

• U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 111 DOCKET 121 LER NUMBER (6) PAGE (3)

NUMBER 121 SALEM GENERATING STATION UNIT 2 05000311 YEAR I SEQUENTIAL NUMBER I REVISION NUMBER 4 OF 4 98 -- 011 - 00 TEXT (If more space is required, use additional copies of NRG Form 366AJ (171 CORRECTIVE ACTIONS

1. The Unit 1 and Unit 2 procedures governing the transfer of vital buses will be changed to require that the pushbutton be pressed and held until the console breaker "close" light illuminates or a SEC undervoltage safeguards actuation occurs. These procedure changes will be completed by October 31, 1998.

NRC FORM 366A (6-1998)