Text

LER 96-003-00:on 960328,determined That Fuel Movement Performed W/Inoperable Refueling Interlock.Caused by Misinterpretation of TS Requirements.Fuel Movement Activities discontinued.W/960426 Ltr
	ML18038B683
Person / Time
Site:	Browns Ferry
Issue date:	04/26/1996
From:	Machon R, Wetzel S; TENNESSEE VALLEY AUTHORITY
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
	LER-96-003-02, LER-96-3-2, NUDOCS 9605030187
	Download: ML18038B683 (16)
	v • d • e

CATEGORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION INBP:9605030187 DOC.DATE: 96/04/26 NOTARIZED: NO DOCKET FACIL:50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH. NAME AUTHOR AFFILIATION r WETZEL,S.A. Tennessee Valley Authority MACHON,R.D. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 96-003-00:on 960328,determined that fuel movement performed w/inoperable refueling interlock. Caused by misinterpretation of TS requirements. Fuel movement activities discontinued.W/960426 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR I ENCL I SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-3-PD 1 1 WILLIAMSiJ. 1 1 INTERNAL: ACRS 1 1 88 2 2 AEOD/SPD/RRAB 1 1 E GENRE 1 1 NRR/DE/ECGB 1 1 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 .1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 2 2 NOAC MURPHY I G ~ A 1 1 NOAC POOREiW. 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5D-5(EXT. 415"2083) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 26 ENCL 26

i' Terxtessee Valley Autriority, Post Oflice Box 2000. Decatu;. Alabama 35609.2000 R. D. (Rick) Machon ~

Vice Presictert t, Browns Ferry Nuclear Plait t April 26,. 1996 U,.S. Nuclear Regulatory Commission 10 CFR 50.73 ATTN: Document Control Desk Washington, D.C. 20555

Dear Sir:

BROWNS PERRY NUCLEAR PLANT (BPN) - UNZTS '1p 2p AND 3 DOCKET.

NOS.:50-259, 260, and 296 - PACZLZTY OPERATZNG LZCENSE DPR-33'2I AND 68 - L1CENSEE EVENT'EPORT 50-260/96003 The enclosed report provides details concerning a condition prohibited by the plant s technical specifications. The event was caused by inadequate reviews of safety assessments for procedure changes made to facilitate refueling outage work.

,This report is being, submitted in accordance with 10 CFR 50.73(a)(2),(i)(B), as an operation or condition prohibited by the plant's technical specifications. If you have any questions concerning this report, please contact Pedro Salas at .(205) 729-2636.

Sincerely, R.:D. achon cc: See page 2 03OO31 9605030lS7 '960426 PDR ADOCK 05000260 S PDR

Oi ii U.S. Nuclear Regulatory Commission Page 2 April 26,, 1996 Enclosure cc (Enclosure),:

Mr. Mark S. Lesser, Branch Chief U.S. Nuclear Regulatory Commission Region 101 II Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 NRC Resident Inspector Browns Ferry Nucl'ear Plant 10833 Shaw Road Athens, Alabama 35611 Mr. J. F. Williams,. Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockvi.lie, Maryland 20852~

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NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 31504104 (4-95) EXPIRES 04/30/88 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMA'nON COLLECTION REQUEST:

LZCENBEE EVENT REPORT (LER) 60.0 HRS. REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE UCENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD COMMENTS REGARDING (Sae reverse for required number of BURDEN ESTIMATE TO THE INFORMATIONANO RECORDS digits/characters for each block) MANAGEMENT BRANCH (TA F33). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 205554001, FACILITY NAME II) oocKET NUllsER I1) PAGE 0) 05000260 1 OF 5 Browns Ferry Nuclear Plant (BFN) Unit,2 TITLE ta)

Fuel Movement Performed With Inoperable Refueling Interlock EVENT DATE (5) LER NUMBER 6 REPORT DATE OTHER FACIUTIES INVOLVED (8)

FACILITYNAME DOCKET NUMBER DAY YEAR SEQUENTIAL REVISION DAY YEAR MONTH NUMBER NUMBER 05000 I FACIUTY NAM DOCKET NUMBER 03 28 96 96 003 00 4 26 96 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR: (Check one or more) (11 MODE (8) N 20.2201(b) 20.2203(a)(2)(v) 50.73(a)(2)(viii) 50.73(a)(2)(I)(B)

POWER 20.2203(a)(1) 20.2203(a)(3)(l) 50.73(a)(2)(ii) 50.73(a)(2)(x)

LEVEL (10) 000 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 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2)(v) Speci ln Abstract below or in PRC Form 366A 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii)

LICENSEE CONTACT FOR THIS LER 12 TELEPHONE NUMBER Oaaruda Araa Coda)

Stewart A. Wetzel, Compliance Engineer (205) 729-7556 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS TO NPRDS a ".;.

.' '...;:,n

'SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED DAY YEAR YES X NO (15)'ONTH SUBMISSION (If yes, complete, EXPECTED SUBMISSION DATE). DATE ABSTRACT (Limit to 1400 spaces, I.e., approximately 15 single-spaced typewritten lines) (16)

On March 28, 1996, at 1540.hours, with Browns Ferry Unit 2 in a refueling outage, fuel movement activities were stopped due to a concern with the operability of the all control rods fully inserted ("all rods in") refueling interlock. Prior to moving fuel, all control rods were verified as fully inserted and the directional control valves for each rod were electrically disconnected. Subsequently, the position indication circuitry for the control rods was bypassed to facilitate refueling outage work. TVA considered that fully inserting the control rods and disconnecting the directional control valves satisfied the intent of the technical specifications (TS) for haying an operable "all rods in" refueling interlock. After fuel movement activities were stopped, TVA reevaluated this condition and determined that it was not in literal compliance with TS requirements. This event.was caused by a misinterpretation of TS requirements for declaring/maintaining the "all rods in" refueling interlock operable. The immediate corrective action was to stop fuel movement and reconnect the position indication circuitry. Corrective actions include taking appropriate personnel corrective actions with the individuals involved. in preparation of the safety assessments for disabling the interlock and in the decision'to,move fuel with the control rod'position inputs disabled. Additionally, the applicable procedures will be revised to prohibit bypassing the position indication circuity when moving fuel. This event is reportable pursuant to 10 CFR 50.73(a)(2)(i)(B) as any operation or condition prohihted by the plant's TS.

Qt NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4.95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACZLZTZ NAME (1) LER NUMBER (6) PAGE (3)

NUMBER NUMBER Browns Ferry Unit 2 05000260 2 of 5 96 -- 003 -- 00 more space rs reqoir ~ use iona colses ofrn Z. PLANT CONDZTZONS At the time of this event, Unit 2 was in a refueling outage with fuel movement activities i;n progress. Unit 3 was operating at approximately 100 percent power. Unit 1 was shutdown and defueled.

ZZ. .DESCRZPTZON OF EVENT A. Event:

On March 23, 1996, at 0200 hours0.00231 days 0.0556 hours 3.306878e-4 weeks 7.61e-5 months , BFN Unit 2 was manually scrammed to begin the Cycle 8 refueling outage. Following the shutdown all control rods were verified as fully inserted and the directional control valves for each rod were electrically disconnected. Subsequently, and in accordance with approved procedures, the position indication circuitry for the control rods [AA] was bypassed to facilitate refueling outage work. On March 26, 1996, at approximately 0230 hours0.00266 days 0.0639 hours 3.80291e-4 weeks 8.7515e-5 months , fuel movement activities commenced.

On March, 28, 1996, at 1540 hours0.0178 days 0.428 hours 0.00255 weeks 5.8597e-4 months , fuel movement activities were stopped .due to a concern with the operability of the all control rods fully inserted ("all rods in") refueling interlock considered that fully inserting the control rods and

[IEL].'VA disconnecting the directional control valves satisfied the intent of the technical specifications (TS) for having an operable "all rods in" refueling interlock. However, after fuel movement activities were stopped, TVA reevaluated this condition and determined that bypassing the control rod position indication inputs to the "all rods in" interlock was not in literal compliance with TS requirements.

Accordingly, because fuel was moved with the "all rods in" refueling interlock technically inoperable, this event is reportable pursuant to 10 CFR 50.73(a)(2)(i)(B) as any operation or condition prohibited by the plant's TS.

B. Zno rable Structures, Co onents, or S stems that Contributed to t e Event:

None.

TS 3.10.A.1 states, in part, that "[t)he required refueling equipment interlocks shall be OPERABLE during in-vessel fuel movement with equipment associated with the interlocks..." TS 4.10%.1 states, in part, that "(p)rhr to any fuel handling with the head off the vessel, the folhwing required refueling equipment interhcks shall be functionally tested: a. All rods inserted..."

NRC FORM 366A (4-95)

Oi i

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NRC FORM 366A 'U.S. NUCLEAR REGULATORY COMMISSION (4 95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY HhME (1) LER NUMBER (6) PAGE (3)

NUMBER NUMBER Browns Ferry Unit. 2 05000260 3 of 5 96 -- 003 -- 00 more space is requir ~ use a iorra copes

c. Dates and roximate Times of Ma or Occurrences:

March 23, 1996, at 0200 CST Unit 2 was shutdown for the Cycle 8 refueling outage.

March 24, 1996 Control rod position indication circuitry inputting to the eall rods in" refueling interlock disabled.

March 26, 1996, at 0230 CST Fuel movement activities commenced.

March 28, 1996, at 1540 CST Fuel movement activities stopped.

March 28, 1996, at 1850 CST Control rod position indication circuitry inputting to the ",all rods in" refueling interlock reconnected.

March 28, 1996, at 2230 CST Fuel movement activities recommenced.

D. Other S stems or Seconda Functions Affected:

None.

Method of Discove This event was discovered when NRC resident inspectors questioned the operabi'lity of the eall rods in" refueling interlock.

F. rator Actions:

Operator actions taken during this event were as expected. Fuel movement activities were stopped when the concern was identified.

G. Safet S stem Res onses:

None.

IIZ . CAUSE OF THE EVENT A. Immediate Cause:

The immediate cause of this event was movement of fuel with an inoperable refueling interlock.

NRC FORM 366A (4-95)

~I ii NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

,LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACZLZTY NAME (1) LER NUMBER (6) PAGE (3)

NUMBER NUMBER Browns Ferry Unit 2 05000260 4 of 5 96 -- 003 -- 00 more space rs requir ~ use e mns copes B. Root Cause:

This event was caused by a misinterpretation of TS requirements for declaring/maintaining the eall rods in" refueling interlock operable. Plant personnel believed that fully inserting all control rods,and electrically disconnecting their directional control valves satisfied the intent of the TS for having an operable "all rods in" interlock. Additionally, the TS require that control rods whose position cannot be positively determined shall be considered inoperable. Inoperable control rods are inserted and electrically disarmed per TS. These conditions were verified as being met prior to bypassing the full-in position switches for the control rods. Plant personnel did not consider this interlock inoperable since all 185 control rods were fully inserted and prevented from being withdrawn from the core. As a result, plant personnel failed to recognize that disabling the control rod position inputs to the "all rods in" refueling interlock functionally disabled'he interlock.

ZV. ANALYSZS OF 'THE EVENT The BFN Updated Final Safety Analysis Report (UFSAR) states that the refueling interlocks aze designed to back up procedural core reactivity controls during refueling operations to prevent an inadvertent criticality, In this event, one of the interlocks was technically inoperable; however, the remaining required refueling interlocks were operable. Additionally, all control rods were fully inserted with their directional control valves electrically disconnected. These other interlocks and fully inserted control rods, combined with established procedural controls, prevented any inadvertent movement of control rods or inadvertent criticality.

Therefore, this event did not affect the safety of the plant or the health and safety of the public.

V. CORRECTIVE ACTZONS Zmmediate Corrective Actions:

The immediate corrective action was to discontinue fuel movement activities and reconnect the control rod position inputs to the "all rods in" refueling interlock.

B. Corrective Actions to Prevent Recurrence:

Appropriate personnel corrective actions will be taken with the individuals involved in the preparation of the safety assessments for disabling the interlock and in the decision to move fuel with the control rod position inputs disabled. Additionally, the two procedures that were revised to allow the interlock to be NRC FORM 366A (4-95)

I+I NRC FORM 866A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACZLZTZ NAME (1) DOCKET LER NUMBER (6) (3)

NUMBER NUMBER'AGE Browns Ferry Unit 2 05000260 5 of 5 96 003 -- 00 more space m reqmr, use dna coppers disabled will be revised to discontinue this practice.a In addition to the above actions, TVA has identified several programmatic enhancements as a result of investigation of this event. For example, TVA plans to develop a briefing paper that discusses this event, the lessons learned, management expectations for preparation of safety assessments and safety evaluations, and the need for literal compliance with TS requirements. TVA plans to distribute this briefing paper to 50.59 qualified individuals at BFN. TVA also plans to include discussion of this event, the lessons learned, and other relevant information in the licensed operator requalification training program. TVA expects to complete these actions by July 25, 1996.a VZ. ADDZTZONAL ZNFORMATZON A. Failed Co onents:

None.

B. Previous LERs on Similar Events:

None.

VZZ . COh%4ZTMENTS Appropriate personnel corrective actions will be taken with the individuals involved in the preparation of the safety assessments for disabling the interlock and in the decision to move fuel with the control rod position inputs disabled. TVA expects to complet:e this action by May 29, 1996.

Energy Industry Identification System (EIIS) system and component codes are identified in the text with brackets (e.g., [XX)).

This action (i.e. procedure revisions) is not a regulatory commitment.

~

These additional actions are considered enhancements and are not commitments.

NRC FORM 366A (4-95)

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ML18038B683

Text

SUBJECT:

Dear Sir:

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