ML20071F467

/03L-0 on 780831:failure of Tri-x Weather Tower'S 100 Meter Delta-T Sensor Sys to Rept Stability Class Info. Calibrations Revised to Ensure Instruments Detect Subsequent Sensor Sys Failures

ML20071F467
Person / Time
Site:	Fort Calhoun
Issue date:	09/27/1978
From:	Otterberg J, Gordon Peterson OMAHA PUBLIC POWER DISTRICT
To:
Shared Package
ML20071F465	List: ML20071F462 ML20071F467
References
LER-78-028-03L, LER-78-28-3L, NUDOCS 7810110103
Download: ML20071F467 (3)

Text

e LICENSEE EVENT REPORT CONTROL BLOCK: l 1

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(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) l0 l i8l 9l N l LICENSEE 7

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CON'T lotil ,"{C[ l L j@l 015 t o 10 l 012 I 815 61 68 l@l69 01813111718 EVENT DATE 74 l@l01of217171 75 REPORT OATE 40 9

7 8 6G DOCKET NUMBER EVENT DESCRIPTION AND PROBABLE CONSEOUENCES h l o 12 l l Durin the ce=pilation and reviev ef weather data for the first 10T8 semi-annual I lo#3l jreport, historically censistent vind stability classes vould net be deter =ined due I loi4l l to a failure of' the Tri-X veather tover's 100 meter Delta-T senser syste= between  !

I o j e l l March 1k,1978. and July 21, 1978. Inanility to reecrt stability class infor=atien is]

l 0 l61 1 not in ec=pliance with USNEC Reculate-v Guide 21. I l

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R 'l l 80 7 8 9 COMP.

SYSTEM CAUSE CAUSE VALVE CODE CODE SUSCODE COMPONENT CODE SUSCODE SUSCOCE loi91 l T l T l@ W@ bj@ ! Il N! Sl Tl RI Ulh l Y l@ W @

12 13 18 19 20 7 8 9 to 11 SEQUENTI AL OCCURRENCE REPORT REVtSION EvtNT YEAR REPORT NO. CODE TYPE NO.

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• E PO R T l7 l8 l l-l l Ol 2l 8] l/l l0l3l lL l l-l l0l 23 24 26 27 28 ;9 30 31 32

_ 21 22 ACTION . FUTURE EFFECT SHUTOOWN ATTACHMENT NPRO4 PRIME COMP. COMPCNENT TAKEN ACTION ON PLANT METHOO MOURS

• SUBMITTED PORM by8. SUPPLIER MANUFACTURER IGl@lrl@

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42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h l i 101 IFailu e of the stan-and-tero en-d in the Delta-T meteerelee ds evster ves not d et ect- l il 11 1 led by instru=ent calibration trecedu es (CV 62'*2 and CP-62 M . "'he calibrstien tro-  !

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{ ] lcedures have been revised to eliminate this deficiency and Encineerinz Evaluatien/

l,13; l Assistance Request No. 78-26 was initiated te zuarantee serarate and redundant Celta-T l I i 3 iA i l channels. 80 7 8 9 9 METHOD CF ,,

F 4 CILITY

• DISCOVERY DESCRIPTION --

STATUS  % POWER OTHER STATU"5 OISCOVERY l1 l5l h l 1l 0l Ol NA l h Occriletion of voorher da_ta f;r rere--l 80 10 n 44 45 46 7 8 9 12 ACTIVITY CONTENT '

P ELE ASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE NA l l NA l l l1 l6ll2l g { l 45 80 7 8 9 10 11 44 PERSONNEL EXPOSURES NUM8ER TV'E DESCRIPTION 11 !:11010101@l;l@! 2A 80 I

' 6 9 11 12 13 l PERSONNE L INJURIES NUV9ER DESCRIPT1CN I

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8 9 1013101@l 12MA 11 80 LCSS OF CR DAMAGE TO FACILITY Q TwE DESCRIPTION s/

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• U8tiCITv NRC USE ONLY

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LER 78-028 Omaha Public Power District Fort Calhoun Station Unit No. 1 Docket No. 05000285 l Attachment No. 1 Safety Analysis A review was made of all vaste gas releases for the period between March 14, 1978, and July 21, 1978. Release rates for this period were based upon X/Q values derived from erroneous control roar. indications of Delta-T. This reviev determined that all releases were made at rates less than release rates allowed

.l by the annual average X/Q values allowed by Technical Specification 2.9(2) which assures compliance with 10 CFR 20.

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LER 78-02B Ornahm Public Power District Fort Calhoun Station Unit No. 1 Docket No. 05000285 Attachment No. 2 Failure Data This is the first reportable incident involving a failure of the westher tower Delta-T measurement system.

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