ML18039A666

Ro:On 981215,HRPCRM 2-RM-90-273C Was Declared Inoperable. Caused by Downscale Indication.Containment RM Will Be Utilized as Planned Alternate Method of Monitoring Until Hrpcrm 2-RM-90-273C Can Be Returned to Operable Status

ML18039A666
Person / Time
Site:	Browns Ferry
Issue date:	12/31/1998
From:	Abney T TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9901120115
Download: ML18039A666 (10)

Text

CATEGORY 1 REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

I ACCESSION NBR:9901120115 DOC.DATE: 98/12/31 NOTARIZED: NO DOCKET FACZL:50-Q60 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH.h7AME ~ AUTHOR AFFILIATION ABNEY', T. E. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)

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SUBJECT:

Provides PM rept as required by Condition G of TS LCO 3.3.3.1,PAMI 6 AC TS 5.6.6.Rept informs that Unit 2 high range primary containment RM,2-RM-90-273C has been inoperable for more than seven days. A DISTRIBUTION CODE: ZE22D COPIES RECEIVED:LTR I ENCL TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

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NOTES:

G RECIPZENT .

COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL 0 PD2-3-PD DEAGAZIO, A 1 AEO 2' INTERNAL: ACRS AEOD/SPD/RRAB 1 ILE ENTER NRR/DE/ECGB 1 1 NRR/DE/EMEB 1 NRR/DRCH/HICB 1 NRR/DRCH/HOHB 1 NRR/DRCH/HQMB 1 NRR/DRPM/PECB 1 NRR/DSSA/SPLB 1 RES/DET/EZB 1 RGN2 FILE 01 1 EXTERNAL: L ST LOBBY WARD <1 LZTCO BRYCE,J H 1 NOAC POORE,W. 1 NOAC QUEENER,DS 1 NRC PDR 1 NUDOCS FULL TXT 1 C

NOTE TO ALL "RIDS" RECIPIENTS: DISTRIBUTION LISTS PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM CONTACT THE DOCUMENT CONTROL OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 23 ENCL

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Tennessee Valley Authority, Post Office Box 2000, Decatur, AIabama 35609-2000 December 31, 1998 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:

In the Matter of Docket No. 50-260 Tennessee Valley Authority BROWNS PERRY NUCLEAR PLANT (BPN) - POST ACCIDENT MONITORING (PAM) INSTRUMENTATION REPORT ON INOPERABLE HIGH RANGE PRIMARY CONTAINMENT RADIATION MONITOR TVA is providing this PAM report as required by Condition G of Technical Specification (TS) Limiting Condition for Operation 3.3.3.1, Post Accident Monitoring Instrumentation, and Administrative Controls TS 5.6.6. This report informs NRC that a Unit 2. High Range Primary Containment Radiation Monitor (HRPCRM),, 2-RM-90-273C, has been inoperable for more than seven days.

HRPCRM 2-RM-90-273C is located in the drywell on Elevation 582~

feet. The primary purpose of the monitor is to provide hi-range monitoring capabilities which are used to indicate the area radiation conditions within the prima~ containment during accident situations.

On December 15, 1998, HRPCRM 2-RM-90-273C was declared inoperable due to a downscale indication. Extensive trouble 9'tf01120115 'tf8i231 PDR ADGCK"05000260 P PDR

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U. S. Nuclear Regulatory Commission Page' December 31, 1998 shooting has determined that the inoperability of the monitor is due to a failure inside the drywell. Although able to alleviate the downscale indication on 2-RM-90-273C during the trouble shooting activities, plant personnel were not able to complete trouble shooting and corrective actions. During power operations the drywell atmosphere is inerted and high radiation levels are present. Hence, additional maintenance activities within the drywell are not possible.

Containment radiation monitor 2-RM-90-273A will be utilized as a planned alternate method of monitoring until HRPCRM 2-RM-90-273C can be returned to operable status. This monitor provides accurate indication of radiological conditions inside the drywell up to 10'ad/hour. Monitors 2-RM-90-273C and 2-RM-90-273A are similar from the standpoint that both receive their input from detectors that are monitoring. the drywell atmosphere and that both detectors are designed for readings up to 10 rad/hour. Monitors 2-RM-90-273C and 2-RM-90-273A are different due to the fact that the signal from 2-RM-90-273C is processed by a Victoreen drawer and indicates readings up to 10 rad/hour while the signal from 2-RM-90-273A is processed by a GEMAC drawer and indicates readings up to 10 rad/hour. While 2-RM-90-273A does not indicate readings above 10 rad/hour, alternative means can be used to monitor the detector output and obtain the readings above 10 rad/hour, if the need arises. Additionally, the Post-Accident Sampling system provides a redundant method for detecting gross fuel failures, through both the sampling of primary system coolant and the containment atmosphere.

On October 31, 1997, 2-RM-90-272C was declared inoperable due to a downscale indication. Accordingly, TVA provided a special report detailing the failure of this radiation monitor in a letter to NRC on November 14, 1997, Browns Ferry Nuclear Plant Special Report On Inoperable High Range Primary Containment Radiation Monitor. Although both HRPCRMs 2-RM-90-272C and 2-RM-90-273C are operating erratically, they

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U. S. Nuclear Regulatory Commission

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, December 31, 1998 are providing some indication of current drywell conditions.

However, because of erratic operation of these detectors, TVA does not consider them operable.

TVA plans to make appropriate repairs to both 2-RM-90-273C and 2-RM-90-272C the next time BFN has a forced Unit 2 outage of sufficient duration in which the drywell is entered, or the next Unit 2 refueling outage (currently scheduled for April of 1999), whichever comes first.

There are no commitments contained in this letter. If you have any questions, please contact me at (256) 729-2636.

Si cerely T. E. Abn Manage of Licensin and Industry Affa'c:

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U. S. Nuclear- Regulatory Commission Page 4 December 31, 1998 cc: Mr. Harold O. Christensen, Branch Chief U.S. Nuclear Regulatory Commission Region II 61 Forsyth Street, S. W.

Suite 23T85 Atlanta, Georgia 30303 NRC Resident Inspector Browns Fexry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611 Mr. L. Raghavan, Project Manager U..S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852

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