ML20045D153

LER-93-007-00:on 930522,discovered That MSL D High Flow Trip Unit Failed Downscale Due to Personnel Error.Appropriate Operations Personnel counselled.W/930617 Ltr

ML20045D153
Person / Time
Site:	Brunswick
Issue date:	06/21/1993
From:	Jonathan Brown, Tabor S CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BSEP-93-0091, BSEP-93-91, LER-93-007-02, LER-93-7-2, NUDOCS 9306280033
Download: ML20045D153 (4)

Text

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, ..- .? .,c Carolina Power & Light Company

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Brunswick Steam Electric Plant l P. O. Box 10429 l Southport, N.C. 28461-0429 June 17, 1993 l

l FILE: B09-13510C '10CFR50.73 .l SERIAL: BSEP-93-0091 i l l U.S. Nuclear Regulatory Commission l

ATTN: Document Control Desk '

Washington, D. C. 20555 BRUNSWICK STEAM ELECTRIC PLANT UNIT 2 t DOCKET NO. 50-324

' LICENSE NO. DRP-62 LICENSEE EVENT REPORT 2-93-007 1

Gentlemen:

In accordance with Title 10 of the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report fulfills the requirement for a written report within thirty (30) days of a reportable occurrence and is submitted in accordance with the format set forth in NUREG-1022, September 1983.

Very truly yours,

/ W

. M. Brown, Plant Manager - Unit 1 Brunswick Steam Electric Plant SFT/

Enclosure cc: Mr. S. D. Ebneter Mr. P. D. Milano BSEP NRC Resident Office 240066 9306280033 930621 I PDR ADOCK 05000324 l

5 PDR ..

4 NRC FORM 366 U.S.HUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3150-0104 (5/92) - EXPIRES: 5/31/95 E STIM ATED BURDEN PER RE SPONSE TO COMPLY WITH T HIS INFORM ATION COLL ECTION REQUE?T; 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMrNTS REGARDING BURDEN ESTMAM TO NE MORMATION AND RECORDS M ANAGEMENT BRANCH IMNBB 77141. U.S. NUCLE AR REGULATORY COMMISSION, WASHING 10N, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PPOJECT (3150 0104). OFFICE OF MANAGEMENT AND SUDGET. WASHINGTON, DC 20503.

F ACluTY NAME (1) DOciriT NUMBER (2) PAGE (3)

Brunswick Steam Electric Plant, Unit 2 05000324 1 of 3 TITLE 141 OUTSIDE TECHNICAL SPECIFICATION 3.3.2 - TRIP SYSTEM NOT PLACED IN TRIP CONDITION WITHIN ONE HOUR EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR MONTH DAY YEAR YEAR NUMBER NUMBER 05000 21 93 F ACILITY NAME DOCKET NUMBER 05 22 93 93 00 06 05000 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 5: (Check one or more of the following)(11)

OPERATING 1

MODE (9) 20 402(b) 20 405(c) 50.73(aH2Hiv) 73.71 lb)

POWER LEVEL (10) 50 50.36(c)(2) 50.73(a)(2Hvii) OTHER 20 405(aH1Hii) 20.405(aH1)(iii) X 50.73(a)(2)(0 50.73(all2)(viiaHA) (Specify in Abstract 20.405f al(I Hiv) 50.73(a)(2)lia 50.73(a)(2HviiiHB) 20.405(aH1 Hv) 50.73(aH2Hiii) 50.73(all2Hz)

LICENSEE CONTACT FOR THIS LER (12)

NAME TEllPHONE NUMBER Steve F. Tabor, Regulatory Compliance Specialist (919) 457-2178 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT M ANUF ACT URER CAUSE SYSTEM COMPONE NT M ANUF A CTURER O R SUPPLEMENTAL REPORT EXPECTED (14) " " " D^* " ' "

EXPECTED YES y NO DATE (15)

[# yea, compiete EXPECTED SUBMISSION DATEl ABSTRACT (Limit to 1400 spaces,i e. approximately fifteen single space typewntten lines) (16)

On May 22, 1993, at approximately 123n hours, while Unit 2 was operating at approximately 50% reactor power, Operations discovered that a Main Steam Line (MSL) D High Flow Trip Unit had failed downscale. The Sbift Supervisor determined that establishing a tracking Limiting Condition for Operation (LCO) was the only action required by the Technical Specifications. At approximately 1925 hours0.0223 days <br />0.535 hours <br />0.00318 weeks <br />7.324625e-4 months <br />, during shift turnover, a review of the tracking LCO revealed that the appropriate compensatory measures as prescribed by the Technical Specification had not been taken. At approximately 1930 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.34365e-4 months <br />, the appropriate Technical Specification action was established (placing the affected trip channel in the tripped condition.) The failure to implement the appropriate action resulted from misinterpretation of the Technical Specification. The cause classification for this event per the criteria of NUREG-1022 is personnel error. Corrective actions to prevent recurrence include counselling of appropriate Operations personnel on the lessons learned j from this event. This event is of minimal safety significance in that other instrumentation was available to provide isolation of Main Steam Line D in the event of a line break. Previous similar events have been reported in LERs 1-90-005, 1-91-008, 1 004, and 1-93-007.

NRC FORM,366A U. S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3150-0104 (5/92) EXPIRES: 5/31/95 ESTIM ATED BURDEN PER RE SPONSE TO COMPLY WITH THl$

INFORM ATION COLLECTION REQUEST: 50.0 HRS. FORWARD

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LICENSEE FVENT REPORT (LER) COMMEN1S REGARDINo uROEN ESTluATE TO THE ,N,ORMATION ann RECORDS M AN AGEME NT BRANCH (MNBB 7714), U.S. NUCLEAR TEXT CudTINUATION REGUL ATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO T HE PAPERWOF;K REDUCTION PROJECT (3150 01041. OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON. DC 20503.

FACluTY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

SEQUE NTIAL REVISION Brunswick Steam Electric Plant """ "

05000324 2 of 3 Unit 2 07 00 93 TEKT Uf more spaceis required, use additionalNRC Form 366A's! (17)

TITLE OUTSIDE TECHNICAL SPECIFICATION 3.3.2 - TRIP SYSTEM NOT PLACED IN TRIP CONDI"' ION WITHIN ONE HOUR INITIAL CONDITIONS On May 22, 1993, Unit 2 was operating at approximately 50% reactor power. Unit 1 was in cold shutdown.

EVENT NARRATIVE On May 22, 1993, at approximately 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br />, while performing a routine tour of the Unit 2 control room backpanels, a reactor operator discovered that the Main Steam Line (MSL)

D High Flow Trip Unit, 2-B21-PDTM-N009B-1, had f ailed downscale. In an effort to identify the action required as a result of the inoperable instrument, the Unit Senior Reactor Operator (SRO) referred to the Technical Specifications and administrative procedures and determined that placing the associated trip channel in the tripped condition was required.

The Unit SRO discussed this determination with the st artup SRO and Shif t Technical Advisor (STA) who concurred with the SRO's assessment. This assessment was then discussed with the Shift Supervisor. The Shif t Supervisor reviewed the same documents and concluded that placing the affected trip channel in the tripped condition was not required and that establishing a tracking Limiting Condition of Operation (LCO) was all that was necessary for the condition. The Unit SRO accepted that decision and initiated tracking LCO #T2 0511 and a work request job order to support repair of the failed instrument.

At 1925 hours0.0223 days <br />0.535 hours <br />0.00318 weeks <br />7.324625e-4 months <br />, during shift turnover, the on-coming shift Unit SRO determined that the previously established tracking LCO #T2-93-0511 did not satisfy the Technical Specification requirements. With fewer than the minimum number of operable channels per main steam line, the Isolation Actuation Instrumentation Technical Specification requires that the inoperable channel be placed in the tripped condition within one hour. The Unit SRO discussed this concern with a second SRO, the Shif t Supervisor, and the STA. The decision was made to cancel the tracking LCO, establish an active LCO, and place the affected channel in the tripped condition.

At 193 0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> , the MSL ' B' isolation logic trip channel was placed in the tripped condition and Active LCO #A2-93-0513 was initiated.

CAUSE OF EVENT The involved Shif t Supervisor misinterpreted the Technical Specification due to inadequate self checking. Furthermore, having made what he believed to be an adequate interpretation of the Technical Specification, the shif t supervisor did not foster a questioning attitude and seek additional independent review when his interpretation differed from that of the Unit SRO, Startup SRO, and the STA.

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. NRC FORM 366A U. S. NUCLEAR REGULATORY COMMISSION APPROVED OMB No. 3150 0104 (5/92)- EXPIRES: 5/31/95 ESTIMATED flVRDE N PE R RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REOUEST: 50.0 HRS. F ORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RE CMOS M AfvAGEME NT BRANCH IMNBB 7714), U .S. NUCLEAR TEXT CONTINUATION REGULATORY COMMIS$lON, WASHINGTON, DC 20M5 0001. AND TO THE FAPERWORK RfDUCTION PROJE CT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20603.

FACILITY NAME (U DOCKET NUMBER (2) LER NUMBER (6) PAGE 13)

BEQUENTIAL REVISION Brunswick Steam Electric Plant """*'" """*'"

05000324 3 of 3 nh 2 93 07 00 TEXT (If more space is required, use additional NRC form 366A 's) (17)

CORRECTIVE ACTIONS The involved Shift Supervisor has been counselled on the importance of adequate self checking during the application of Technical Specifications, the need to maintain a questioning attitude and invoke independent reviews when dif fering interpretations of the Technical Specification exist, and the need to employ a team approach to the analysis of plant conditions and the verification of compliance to the Technical Specifications.

The involved Shift Supervisor has discussed the lessons learned from this event with the other Operations Shift Supervisors.

SAFETY ASSESSMENT The main steam line high flow instrumentation provides isolation of the main steam lines in the event of a line break. There are four high flovi instruments installed on each main  ;

steam line, two of which provide input to the ' A' isolation logic trip channel and two of which provide input to the 'B' isolation logic trip channel. This event is of minimal safety significance in that only one of the two 'B' isolation logic trip c' annel Main Steam Line D high flow trip units was inoperable. The other 'B' isolation 'agic trip channel instrument was op'*able and capable of actuation in the event of a ma'. steam line break.

However, had the other ' B' isolation logic trip channel flow instrum' .it also failed, Main Steam Line D isolation would have occurred due to the actuati a of other operable instrumentation monitoring main steam line tunnel temperature, ma! . steam isolation valve pit temperature, and main steam line low pressure.

PREVIOUS SIMILAR EVENTS Previous similar events have been reported in LERs 1-90-005, 1-91-008, 1-93-004, and 1 007.

EIIS COMPONENT IDENTIFICATION System /Comoonent EIIS Code PCIS JM l

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