ML18038A999

LER 94-007-02:on 940929,discovered That Condition Involving Noncompliance w/10CFR50 App R,Criterion III.L.2.d Existed. Caused by Failures to Correctly Interpret/Implement Requirements of Calculations.Rept initiated.W/941031 Ltr

ML18038A999
Person / Time
Site:	Browns Ferry
Issue date:	10/31/1994
From:	AUSTIN S, MACHON R D TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-94-007, LER-94-7, NUDOCS 9411090409
Download: ML18038A999 (20)

Text

J.wL~LW J.A J.J ACCELERATED RIDS PROCI'.SSIXG)

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)ACCESSION NBR:9411090409 DOC~DATE: 94/10/31 NOTARIZED:

NO DOCKET FACIL:50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH.NAME AUTHOR AFFILIATION AUSTIN,S.Tennessee Valley Authority MACHON,R.D.

Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 94-007-02:on 940929,discovered that condition involving noncompliance w/10CFR50 App R,criterion III.L.2.d existed.Caused by failures to correctly interpret/implement requirements of caculations.Rept initiated.W/941031 ltr.DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE: TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.NOTES: RECIPIENT ID CODE/NAME PD2-4-PD INTERNAL: ACRS AEOD/SPD/RRAB NRR/DE/EELB NRR/DORS/OEAB NRR/DRCH/HICB NRR/DRSS/PRPB NRR/DSSA/SRXB RES/DSIR/EIB EXTERNAL: L ST LOBBY WARD NOAC MURPHY I G~A NRC PDR COPIES RECIPIENT LTTR ENCL ID CODE/NAME 1 1 WILLIAMS,J.

1 A/~OA'B/DSP 1 FI LE CENTER 1 RR/DE/EEEB 1 NRR/DRCH/HHFB 1 NRR/DRCH/HOLB 2 NRR/DSSA/SPLB 1 NRR/PMAS/IRCB-E 1 RGN2 FILE 01 1 1 LITCO BRYCE I J H 1 1 NOAC POORE,W.1 1 NUDOCS FULL TXT COPIES LTTR ENCL 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE KVASTE!CONTACTTHE DOCI.'CLIENT CONTROL DESK.ROOh I P I-37 I EXT.5(H-20S3)TO F LI XI!NATE YO!.'R NAZI E F ROTI DISTRIBUTION, LISTS FOR DOCK 4IEX'I'S l'OL'ON" I'L'I'.D!FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 27 ENCL 27 0

Tennessee vasey Authority.

post onice Box 2000.Decatu..Ataharna 35609 2000 R.D.(Rick)Machon Vice President, Browns Ferry Huctear Pfant October 31, 1994 U.S.Regulatory Commission ATTN: Document Control Desk Washingtoni D AC 20555 r

Dear Sir:

10 CFR 50.73 BROWNS FERRY NUCLEAR.PLANT (BFN)-'UNITS 1g2g AND 3-DOCKET NOS~50-259~50-260~AND 296-FACILITY OPERATING LICENSE DPR-33'2'ND 68-LICENSEE EVENT'REPORT 50-260/94007 The enclosed report provides details concerning a noncompliance with Appendix R resulting in Unit 2 being in a condition that was outside its design basis and in a condition not covered by the plant's operating instructions.

This report is being submitted in accordance with 10.CFR 50.73 (a)(2)(ii).Sincerely, R.D.achon.Site Vice President Enclosure cc: See page 2 r 080078 94il090409 94'i0 i'DR ADOt.K 05000260 PDR/P 0 I~I Lj U..S.Nuclear Regulatory Commission Page 2 October'1, 1994 cc (Enclosure):

INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 Paul Krippner.American Nucl'ear Insurers Town.Center,'Suite 300S 29 South Main Street West Hartford, Connecticut 06107 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens, A'labama 35611 Regional Administrator U.S.Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr.J.F.Williams, Project Manager U.S.Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Ol 0 I' NRC FORH 366 (5-92)U.S.NUCLEAR REGULATORY CDNII SSION APPROVED BY INIB NO.3150-0104 EXPIRES 5/31/95 LICENSEE EVENT REPORT (LER)(See reverse for required number of digits/characters for each block)ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTIOH REQUEST: 50.0 HRS.FORWARD COMHENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS HANAGEMENT BRANCH (HNBB 7714), U.S.NUCLEAR REGULATORY COMHISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3140-0104), OFFICE OF MANAGEHENT AND BUDGET WASHINGTON DC 20503.FACILITY NAME (1)Browns Ferry Nuclear Plant (BFN)Unit 2 DOCKET NIMSER (2)05000260 PAGE (3)1 OF 7 TITLE (4)Noncompli.ance With 10 CFR 50 Appendix R Results in Unit 2 Being Outside Its Design Basis And Zn a Condition Not Covered By The Plants Operating Instructions HONTH DAY 09 29 YEAR YEAR 94 94 EVENT DATE 5 LER NINBER 6 SEQUENTIAL HUHBER 007 REVISION NUMBER 00 MONTH DAY YEAR REPORT DATE 7 FACILITY NAME NA FACILITY NAME NA DOCKET NUMBER DOCKET NUHBER OTHER.FACILITIES INVOLVED 8 OPERATING INX)E (9)POWER LEVEL (10)N 73 THIS REPORT IS SUBMITTED PURSUANT'0.402(b)20.405(a)(1)(i) 20.405(a)(1)(ii) 20.405(a)(1)(iii) 20.405(a)(1)(iv) 20.405(a)(1)(v) 20.405(c)50.36(c)(1) 50.36(c)(2) 50.73(a)(2)(i)

X 50.73(a)(2)(ii) 50.73(a)(2)(iii) 50'3(a)(2)(iv) 50.73(a)(2)(v) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(x) 73.71(b)73.71 (c)OTHER (Specify in Abstract below and in Text, NRC Form 366A TO THE REQUIREMENTS OF 10 CFR: Check ono or mor e 11 LICENSEE CONTACT FOR THIS LER 12 NAME Steve Austin, Compliance Licensing Engineer TELEPHONE NUHBER (Include Area Code)(205)729-2070 C(NPLETE ONE LINE FOR EACH C(NPONENT FAILURE DESCRIBED IN THIS REPORT 13 CAUSE SYSTEH COMPONENT HANUFACTURER REPORTABLE TO NPRDS CAUSE SYSTEH COHPONENT MANUFACTURER REPORTABLE TO NPRDS SUPPLEMENTAL REPORT EXPECTED 14 YES (lf yes, complete EXPECTED SUBHISSION DATE).X NO EXPECTED SUSHI SS ION DATE (15)MONTH DAY YEAR ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typeNritten lines)(16)On September 29, 1994, at approximately 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> TVA discovered that a condition involving noncompliance with 10 CFR Part 50 Appendix R, Criterion ZZZ.L.2.d.

existed.Specifically, TVA discovered that the Unit 2 suppression pool level indication was not available due to a loss of the.supporti.ng power supply, which is fed from 480V Shutdown Board 2B.Additionally, the Appendix R Safe Shutdown Program did not require compensatory measures for Fire Area 18.This event is reportable pursuant to 10 CFR 50.73(a)(2)(ii)(B) as a conditi.on outside the design basis, of the plant, and 10 CFR 50.73(a)(2)(ii)(C) as a condition not covered by the plant's operating and emergency instructions.

This event resulted from failures to correctly interpret/implement the applicable requirements of the calculations and/or design criteria used during the initial development of the Unit 2 Appendix R program.TVA will revise the Safe Shutdown Program along with appropriate procedures and calculations.

Finally, TVA will perform a comparative review of the Required Equipment Calculation against the Browns Ferry Unit 2 Safe Shutdown Program.NRC FORH 366 (5-92) 41 NRC FORM 366A (5-92)U S.NUCLEAR REGULATORY CONIISSIDN LICENSEE EVENT REPORT TEXT CONTINUATZON APPROVED BY NNI NO.3150-0104 EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY illTH THIS INFORHATION COLLECTION REQUEST: 50.0 HRS.FORUARD COHHENTS REGARDING BURDEN ESTIHATE TO THE INFORHATION AND RECORDS MANAGEHENT BRANCH (MNBB 7714), U.S.NUCLEAR REGULATORY COHHISSION, NASHINGTON, DC 20555-0001, AND TO THE PAPERNORK REDUCTION PROJECT (3150-0'l04), OFFICE OF HANAGEHEHT AND BUDGETS llASHINGTON, DC 20503 FACILITY NAME (1)Browne Ferry Unit 2 DOCKET NNIBER (2)05000260 YEAR 94 LER NNIBER (6)SEQUENTIAL NUMBER 07 REVISION NUMBER 00 PAGE (3)2 of 7 TEXT lf more s ace is r uired use additional co ies of NRC Form 3 66A (17)I~II'ONDITIONS Unit 2 was at 2333 megawatts thermal or approximately 73 percent power.Units 1 and 3 were defueled.DESCRIPTION OF EVENT Event: On September 29, 1994, at approximately 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, during development of the Unit 3 Appendix R program, TVA discovered that a condition involving noncompliance with 10 CFR Part 50 Appendix R, Criterion IIZ.L.2.d, existed in that Unit 2 suppression pool level indication

[LI]was not available for a loss of the supporting power supply in Fire Area 18.Specifically, the list of fire areas in which compensatory measures are required for a loss of Instrument and Control Bus (Z&C)2B[EF]contained in the Browne Ferry Nuclear Plant Unit 2 Safe Shutdown Program was not complete.During a review of Unit 2 Appendix R calculations, TVA determined that compensatory measures were not required by the Browns Ferry Nuclear Plant Unit 2 Safe Shutdown Program for a loss of Instrument and Control Bus 2B in the Unit 2 Battery Board Room portion of Fire Area 18.Fire Area 18 consists of the Unit 2 Battery[BTRY]and Battery Board Room located in the Control Building[NA].Additionally, it was determined that IEC Bus 2B is not available for providing power to the suppression pool level indicator during an Appendix R fire in Fire Area 18.A postulated failure of cables in the normal supply power to the bus, 480V Shutdown Board 2B[EB], in conjunction with a current procedural requirement to de-energize the alternate source of power to IGC Bus 2B, 480V Shutdown Board 1B, will take the suppression pool indicator out of service.Upon discovery of this event, TVA entered a Unit 2 Appendix R Limiting Condition of Operation which established compensatory measures as required by the Unit 2 Appendix R Safe Shutdown Program.This condition has existed since Unit 2 returned to service in May 1991.This event is reportable pursuant to 10 CFR 50.73(a)(2)(ii)(B), as a condition that was outside the design basis of the plant in that the suppression level monitoring capability was not available because of a potential loss of the supporting power supply in Fire Area 18.Additionally, because the procedural I!I NRC FORK 366A (5-92)U.S.NUCLEAR REGULATORY CQIIISSI ON LICENSEE EVENT REPORT TEXT CONTINUATION APPROVED BY (HS NO.3150-0104 EXPIRES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COHPLY WITH THIS INFORHATION COLLECTION REQUEST: 50.0 HRS.FORWARD COHNEHTS REGARDING BURDEN EST INATE TO THE INFORHAT ION AND RECORDS NANAGEHENT BRANCH (HNBB 7714), U.S~NUCLEAR REGULATORY COHNISS ION~WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF HANAGENENT AND BUDGET,'WASHINGTON, DC 20503 FACILITY RANE (1)Browns Ferry Unit 2 DOCKEI'OIBER (2)05000260 YEAR 94 LER NOSER (6)SEQUEHTIAL NUHBER 07 REVISION NUHBER 00 PAGE (3)3 of 7 TEXT If more s ce is r uired use sdditionst co ies of NRC Form 366A ('l7)B C recyxirements did not take into account for the loss of I&C Bus 2B, TVA reports this event pursuant to 10 CFR 50.73(a)(2)(ii)(C), as a condition not covered by the plant's operating and emergency procedures.

Ino erable Structures Com onents or S stems that Contributed to the Event: None.Dates and A roximate Times of Ma'or Occurrencest September 29, 1994 at 1300 CST TVA identified noncompliance with 10 CFR Appendix R.A compensatory action firewatch in accordance with the Unit 2 Appendix R Safe Shutdown Program was established.

September 29, 1994't 1353 CST A one hour nonemergency notification was made in accordance with 10 CFR 50.72.(b)(1)(ii).

D~Other S stems or Seconda Function Affected: None.Method of Discove I Fo The condition of noncompliance with the requirement of Appendix R was identified during the development of the Unit 3 Appendix R Program.0 erator Actionst G.None.Safet S stem Res onses: None.

1 II 4i ("

NRC FORH 366A (5-92)U.S.NUCLEAR REGULATCHIY CWISSION LICENSEE EVENT REPORT TEXT CONTINUATION APPROVED BY CHHI NO.3150-0104 EXPIRES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COHPLY IIITH THIS INFORHATION COLLECTION REQUEST: 50.0 BR'ORIIARD COHHENTS REGARDING BURDEN ESTIHATE TO THE INFORMATION AND RECORDS HANAGEHENT

'RANCH (HNBB 7714), U.ST NUCLEAR REGULATORY COHHISSION>>

l!ASHINGTOH, DC 20555-0001, AND TO THE PAPERNORK REDUCTION PROJECT (3150-0104), OFFICE OF HANAGEHENT AND BUDGET, IIASNINGTON, DC 20503 FACILITY HAHE (1)Browns Ferry Unit 2 DOCKET imIER C2)05000260 YEAR 94 LER lmIER C6)SEQUENTIAL NUHBER 07 REVISION NUHBER 00 PAGE C3)4 of 7 TEXT If more s ce is r uired use edditionet co ies of NRC Form 366A (17)III'AUSE OF THE EVENT A.Immediate Cause: B>>Noncompliance with 10 CFR 50 Appendix R.Root Cause: The event resulted from failures to correctly interpret/implement the applicable requirements of the calculations and/of design criteria used during the initial development of the Unit 2 Appendix R program.Specifically, the personnel involved in the development of the Unit 2 program failed to recognize that the normal feed to IEC Bus 2B was not available during an Appendix R fire in Fire Area 18.C.Contributin Factors: None.IV>>ANALYSIS OF THE EVENT The Unit 2 Appendix R Safe Shutdown Program requires torus level monitoring from the main control room and the remote shutdown stations.An Appendix R event in Fire Area 18 could result in loss of the power supply to the Suppression Pool Level Indicator.

As noted in the Safe Shutdown Analysis, suppression pool water level instrumentation aids the operator in confirmation of the suppression pool as at heat sink.Additionally, the suppression pool level indicator could be used to ensure that adequate suppression pool level would be available for Reactor Pressure Vessel[RCT]Main Steam Relief Valve (MSRV)[SB]

steam suppression and for Residual Heat Removal[BO]system pump net positive head.Furthermore, level indication would prevent overfill of the suppression pool.The only sources of water that have the potential to overfill the suppression pool are the Condensate Storage Tank (CST)[KA]system, Wheeler Reservoir[BS], and the other Units'uppression pools.The interties between these have been evaluated and a single spurious operation will not result in overfill of the suppression pool.

El 0 NRC FORK 366A (5-92)U.S.NUCLEAR REGULATORY COHISSION LICENSEE EVENT REPORT TEXT CONTINUATION APPROVED BY QIB NO.3150-0104 EXPIRES'/31/95 ESTIMATED BURDEN PER RESPONSE TO COHPLY MITH THIS IHFORHATIOH COLLECTIOH REQUEST: 50.0 HRS~FORllARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AMD RECORDS NAMAGEHENT BRANCH (HNBB 7714), U.S.NUCLEAR REGULATORY COMMISSIONS llASHINGTOH, DC 20555-0001, AND TO THE PAPERMORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AMD BUDGET/'MASHINGTON, DC 20503 FACILITY MANE (1)'Browns Ferry Unit 2 DOCKET HWSER (2)05000260 LER MWBER (6)YEAR SEQUENTIAL NUMBER 94 07 REVISION NUMBER 00 PAGE (3)5 of 7 TEXT If more s ce is re uired use additions(co ies of NRC Form 366A (17)Additionally, the only connections from the CST to the suppression pool'depending on electrically operated valves are the High Pressure Coolant Injection (HPCZ)[BG]system and Reactor Core Isolation Cooling (RCIC)[BN]system minimum flow lines.If these systems are actuated, a 4 inch rise in suppression water level in three hours can be expected.Draining of the torus level is not of a concern because the connections are either manually isolated or pump operation is required to affect the level.HPCZ , RCZC, Residual Heat Removal system, and the Core Spray[BM]system all take suction from the suppression pool.A single spurious operation of the HPCZ or RCIC will not cause the system to remove water to the CST.Also, if water is pumped into the RPV by one of these systems, it will eventually be returned to the suppressi.on pool through the MSRVs.Fire Area 18 has a combined combustible loading of 39000 BTU/fts with a fire severity of 29 minutes.The area is provi.ded with an addressable area wide coverage smoke detection system.Additionally, the area is protected by a manually actuated sprinkler system.Fire hose stations and fire extinguishers are available in the general area to support manual suppression activities.

The detection system provides an early warning in order to manually actuate.the sprinkler system.Furthermore, TVA's administrative controls will limit hot work activiti.es and limit the amount of combustibles allowed in the area.A highly unlikely chain of events would have to take place in order to have a fire of the magnitude that would di.sable the normal feed and require the operator to trip the alternate feed to the suppression pool level indicator.

Additionally, existing analysis indicates that.suppression pool level is not si.gnificantly changed during emergency shutdown conditions.'herefore, TVA concludes that the condition described above did not jeopardize the public health and safety.NRC Generic Letter 86-10, Implementation of Fi.re Protection Requirements, Enclosure 2, Page 24, Appendix R Questions and Answers paragraph 5.3.7 Torus Level Indication i%1 I NRC FORH 366A (5-92)U.S.NUCLEAR REGULATORY CQtlISSION LICENSEE EVENT REPORT TEXT CONTINUATION APPROVED BY QNI NO.3150-0104 EXPIRES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COHPLY MITH THIS INFORHATION COLLECTION REQUEST: 50.0 NRS.FORNARD COHHENTS REGARDING BURDEN ESTIHATE TO THE INFORHATION AND RECORDS HANAGEHENT BRANCH (HNBB 7714), U.ST NUCLEAR REGULATORY COHHISSION, llASHINGTON, DC 20555-0001, AND TO THE PAPERNORK REDUCTION PROJECT (3150-0104), OFFICE OF HANAGEHENT AND BUDGET, IJASHINGTON, DC 20503 FACILITY NAHE (1)DOCKET NWBER (2)YEAR LER Nil(BER (6)SEQUENTIAL NUHBER REVISION NUHBER PAGE (3)Browns Ferry Unit 2 05000260 94 07 00 6 of 7 TEXT tf more s ace is r ired use additional co ies of NRC Form 366A (17)V.CORRECTIVE ACTIONS A.Immediate Corrective Actions<A Problem Evaluation Report was initiated in accordance with the TVA Corrective Action Program.TVA established compensatory actions in accordance with the BFN Unit 2 Appendix R Safe Shutdown Program.B.Corrective Actions to Prevent Recurrencet TVA will revise the Safe Shutdown Program to show compensatory measures for Fire Area 18.Additionally, TVA will revise applicable calculations to show that the alternate feed to ZGC Bus is available for Fire Area 18 and delete the manual action to deenergize the alternate power source for ZGC Bus 2B for Fire Area 18.VI~TVA will revise the Safe Shutdown Instruction for Fire Area 18 to support the alternate alignment for Fire Area 18 (480V Shutdown Board 1B).TVA will perform a comparative review of the Required Equipment Calculation against the Browns Ferry Unit 2 Safe Shutdown Program to ascertain if any other technical inadequacies similar to the ones described in this report are present.ADDITIONAL INFORMATION Ao Failed Com onents: Bo None.Previous LERs on Similar Events: LER 260/94002 was issued for an event involving noncompliance with Appendix R that resulted from individuals failing to correctly interpret/implement the applicable requirements of the calculation and/or design criteria used during the original development of the Unit 2 Appendix R'rogram.The corrective actions identified by this LER would not have prevented this event.

Ol 0~'lt NRC FORM 366A (5-92)U.S NUCLEAR REGULATORY COMMISSION APPROVED BY (N(B NO.3150-0104 EXPIRES 5/31/95 FACILITY NAME (1)DOCKET NUMBER (2)LICENSEE EVENT REPORT TEXT CONTINUATZON ESTIMATED BURDEN PER RESPONSE TO COHPLY WITH THIS INFORHATION COLLECTION REQUEST: 50.0 HRS~FORWARD COHHENTS REGARDING BURDEN'STIMATE TO THE INFORHATION AND RECORDS HANAGEMENT, BRANCH (MNBB 7714), U.S~NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFF ICE OF HANAGEMENT AND BUDGET t WASHINGTON, DC 20503 PAGE (3)LER NUMBER (6)Browns Ferry Unit 2 05000260 YEAR 94 SEQUENTIAL NUHBER 07 REVISION NUMBER 00 7 of 7 TEXT If more s ce is r uired use additional co ies of NRC Form 366A (17)VZZ.Commitments 1., TVA will revise the Safe Shutdown Program to show compensatory measures for Fire Area 18.The revision will be completed by January 5, 1995.2~3~4~TVA will revise applicable calculations to show that the ,alternate feed to Z&C Bus is available for Fire Area 18 and delete the manual action to de-energize the alternate power source for Z&C Bus 2B for Fire Area 18.The revisions will be completed by December 16, 1994.TVA will perform a comparative review of the Required Equipment Calculation against the Browns Ferry.Unit 2 Safe Shutdown Program to ascertain if any other technical inadequacies similar to the ones described in this report are present.This evaluation will be completed by December 16, 1994.TVA will revise the Safe Shutdown Instruction for fire area 18 to support the alternate alignment for Fire Area 18.The revision will be completed'y December 30, 1994.'Energy Industry Identification System (EZZS)system,and component codes are identified in the text with brackets (e.g.,[XX]).

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