ML18106B147

LER 99-001-00:on 990228,reactor Scram Was Noted as Result of Turbine Trip.Caused by Operator Error.Lesson Plans Revised to Explicitly Demonstrate Manner in Which Valve Functions. with 990329 Ltr

ML18106B147
Person / Time
Site:	Salem
Issue date:	03/29/1999
From:	Garchow W, Nagle J Public Service Enterprise Group
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
LER-99-001-02, LER-99-1-2, LR-N990146, NUDOCS 9904080221
Download: ML18106B147 (4)

Text

e OPS~G Puolic Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit MAR 2 91999 LR-N990146 Regional Administrator U.S. Nuclear Regulatory Commission Region 1 475 Allendale Road King of Prussia, PA 19406-1415 Gentlemen:

LICENSEE EVENT REPORT 272/99-001-00 SALEM GENERATING STATION- UNIT 1 FACILITY OPERA TING LICENSE NO DPR 70 DOCKET NO. 50-272 This Licensee Event Report entitled "REACTOR SCRAM AS A RESULT OF TURBINE TRIP" is being submitted in accordance with the criteria of 10CFR50.73(a)(2)(iv)

Attachment

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C U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Distribution:

LER File 3.7 9904080221 6~gg3~72 PDR ADOCK PDR s

The> ~L)\\*er is in :*L)l!r lunds.

95-2168 REV. 6;94

,.NRC FORM 366 U.S. NUCLEJ!1R REGU ORY COMMISSION APPRO " BY OMB NO. 3150-0104 EXPIRES 06/30/2001 (6-1998) Estimated burden per response to comply with this mandatory information collection request: 50 hrs. Reported lessons learned are incorporated into the LICENSEE EVENT REPORT (LER) 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 to the Paperwork (See reverse for required number of Reduction Project (3150-0104). Office of Management and Budget, Washington. DC 20503 If an infonmation collection does not display a currently digits/charact~rs for e~ch block) valid OMB control number. the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

FACILITY NAME (1) DOCKET NUMBER (2)

SALEM GENERATING STATION UNIT 1 TITLE 141 05000272 I""":' OF 3 I REACTOR SCRAM AS A RESULT OF TURBINE TRIP EVENT DATE (5) LER NUMBER (6) REPORT DA TE (7) OTHER FACILITIES INVOLVED (8)

FACILITY NAME DOCKET NUMBER I SEQUENTIAL I REVISION MONTH DAY YEAR YEAR NUMBER NUMBER MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 02 28 99 99 001 00 03 29 99 05000 OPERATING T\..llC Rl=Pf)RT I<: <:I IDMITT~ n DI IDCI Ill.NT Tf) THI= ocnl IDCI nCl\ITC ni: 1 f\ rt:<> n. II"' ho~~ nno n* -~*ol 111 l MODE (9) 1 20.2201 {b) 20.2203(a){2){v) 50.73{a)(2){i) 50. 73(a){2) (viii) 20.2203(a){1) 20.2203(a)(3){i) 50. 73{a)(2)(iil 50. 73{a){2){x)

POWER LEVEL (10) 60 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) x 50. 73{a)(2) {iv) OTHER 20.2203(a){2)(iii) 50.36{c){1) 50. 73{a)(2){v)

Specify in Abstract below r 20.2203{a) (2) {iv) 50.36{c){2) 50. 73{a){2){vii) or in NRC Form 366A LICENSEE CONTACT FOR THIS LER !12)

NAME TELEPHONE NUMBER (Include Area Code)

John C. Nagle Senior Licensinq Engineer 609-339-3171 rn**DI l=T~ nMt: I ll\IC i:nR t:l\l"'U c/\11 11oc nr-.,ro1<>cn 1r.1 *u1c oconoT 1 'l1 1~.* ;;*

REPORTABLE REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER TO EPIX f*'i CAUSE SYSTEM COMPONENT MANUFACTURER To* EPIX i

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'*1 C:llDDI c*nl=NTl!.I Rl=Pf)RT I-A ~* 114l *~ONT.H n"v YFAI>

EXPECTED I YES SUBMISSION (If ves, comolete EXPECTED SUBMISSION DATE). I x INO DATE (15)

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

At 1:38 AM, on February 28, 1999, the Salem Unit 1 Reactor was automatically shut down due to a Low Oil Pressure Trip of the Main Turbine. The unit was operating at 60% power prior to the shutdown and was being maintained at this power level to allow maintenance troubleshooting activities. Preparations were also being made to allow maintenance to repair a leaking Main Turbine Lube Oil Cooler. While adjusting the cooler isolation valve, the operators inadvertently positioned the valve off of its closed seat., allowing oil from the in service cooler to enter the partially drained out-of-service cooler.

This diverted flow caused a momentary drop in the turbine oil pressure and resulted in the automatic shutdown of the Main Turbine and Reactor. A root cause investigation determined that the cause of this event was personnel error.

This event is being reported pursuant to §50. 73 (a) (2) (iv) Licensees shall report "any event or condition that resulted in a manual or automatic actuation of any Engineered Safety Feature (ESF), including the Reactor Protection System (RPS).'*'

NRC FORM 366 (6-1998)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET (2)

FACILITY NAME (1) NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR I SEQUENTIAL NUMBER I REVISION NUMBER Salem Generating Station Unit 1 05000272 99 0 01 00 2 OF 3 TEXT (If more space is required, use additional copies of NRG Form 366AJ (17)

PLANT AND SYSTEM ID~NTIFICATION Westinghouse - Pressurized Water Reactor (Main Turbine Lube Oil Cooler Swap Over Valve) {LL/ISV}*

• Energy Industry Identification System (EIIS) codes and component function identifier codes appear as {SS/CCC} in the text.

CONDITIONS PRIOR TO OCCURRENCE The unit was operating at 60% power prior to the shutdown and was being maintained at this power level to allow maintenance troubleshooting to be performed on the 12 Steam Generator Feed Pump. Preparations were also being made to allow maintenance to repair a leaking Main Turbine Lube Oil Cooler.

DESCRIPTION OF OCCURRENCE At 1:38 AM, on February 28, 1999, the Salem Unit 1 Reactor was automatically shutdown due to a Turbine Trip. The operators were adjusting the position of a Schutte and Koerting six way valve {LL/ISV}on the main turbine lube oil system. This valve is used to select between the two available coolers and also acts as an isolation valve for the out-of-service cooler. Preparation were being made.to perform maintenance on the out-of-service oil cooler. Due to excess leakage into the cooler attempts were being made to more tightly seat the TL45 valve. While adjusting the isolation valve, the operators positioned the valve partially off of its closed seat, allowing oil from the in-service cooler to enter the partially drained out-of-service cooler. This diverted flow caused a momentary drop in the turbine oil pressure and resulted in the automatic shutdown of the Main Turbine. The turbine trip caused the Reactor to trip, as designed.

The operators responded to the automatic shutdown as directed by the plant's Emergency Operating Procedures and the unit was stabilized and placed in a shutdown condition without incident.

NRC FORM 366A (6* 1998)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET (2)

FACILITY NAME (1) NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR I SEQUENTIAL NUMBER I REVISION NUMBER SALEM GENERATING STATION UNIT 1 05000272 99 0 01 00 *3 OF 3 TEXT (If more space is required, use additional copies of NRC Form 366AJ ( 17)

CAUSE OF OCCURRENCE .

The cause of the shutdown was operator error. The error was attributed to mis-operation of the cooler swap-over valve. Operation of this valve is an infrequent occurrence. The operators did not know that their attempts to more tightly close the valve would result in the valve being partially moved off of the closed seat. A 4-hour report was made to the NRC as required by the plant's Emergency Classification Guide and 10CFRSO. 72 (b) (2) (ii).

The event investigation has determined that there was a broad lack of awareness of the precise design and operation of this unique valve. The valve is equipped with two handwheels mounted one behind the other on the same axis. The outer handwheel selects the cooler and the inner handwheel seats the valve. Prior to the this event personnel believed that the inner handwheel locked and unlocked the valve position. In fact, the inner handwheel raised and lowered the valve plug (a tapered cylinder) thus seating and unseating the valve PRIOR SIMILAR OCCURRENCES A review of 1997 and 1998 Licensee Event Reports and Inspection Reports for Salem Units 1 and 2 did not identify any incidents where lack of knowledge of equipment design features resulted in a significant plant transient.

SAFETY CONSEQUENCES AND IMPLICATIONS Although the turbine trip and attendant reactor shutdown have minimal safety consequences, it is not desirable to unnecessarily challenge these systems.

All systems and safety features performed as designed and the unit safely shut down.

CORRECTIVE ACTIONS Lesson plans have been revised to explicitly demonstrate the manner in which this valve functions. Operating Procedures have been revised to address the proper operation of the valve. Lessons Learned will be provided to the operating crews prior to the end of the second quarter (June 30, 1999).

NRC FORM 366A (6-1998)