ML20090L084

Ro:On 840414,accuracy of Temp Difference Between Nominal Meteorological Tower Elevations of 27 & 200 Ft Found Inconsistent.Caused by Electronic Drift of 200-ft Elevation Delta Temp Translator Card.Card Recalibr

ML20090L084
Person / Time
Site:	Nine Mile Point
Issue date:	05/14/1984
From:	Lempges T NIAGARA MOHAWK POWER CORP.
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NMP-8438, NUDOCS 8405250032
Download: ML20090L084 (3)

Text

r 1 ,. NAIP-8438 NIAGARA MOHAWK POWER CORPORATION NIAGARA MOHAWK 300 Erit BOULEVARD. WEST SYR ACUSE. N. Y.13 202 Alay 14,1984 Or. Thomas E. blurtcy Regional Adninisttator United States Nacicar Regulatory Commission Region I 1

631 Park Avenue King of Prussia, Pennsyivania 19406 Re: Occhet No. 50-220 Ocar 0.t. blaricyt In accordance seith Nine bliie Point Nucicar Station Unit 1 Technicai i Specifications, see hereby subni.t the following 30 day Nontoutine i

Envitonmental Operating Report. This report a submitted in accordance leith the required content of section 4.6.2 of the Appendix B Technical Specifications.

Vety Ltuiy yours, d

Thomas E. Lerpges Vice President i Nacicar Generation 1

TEL/HJFlio ccs Director 0ffice of NRR (1 copy)

T.J.PerfJns T.W Roman E.W. Leach H.J. Fianagan

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NONROUTINE ENVIR0h)1 ENTAL OPERATING REPORT Nine Mile Point Nuclear Station Unit 1 Docket No. 50-220 May 14, 1984 Introduction This Nonroutine Environmental Orerating Report is submitted in accordance with Section 4.6.2a of the Nine Mile Point Nuclear Station Unit 1 Technical Specifications, Appendix B (Environmental Technical Specifications). Section 4.6.2a indicates that a report shall be submitted in the event that section 2 " Limiting Conditions for Operation" or a report level or specification l' reached as specificed in section 3, " Environmental Surveillant ".

Descripti_o_n Appendix B, section 3.1 requires that the meteorological monitoring system shall measure parameters as prescribed by Table 3.1-1. Table 3.1-1 requires that the ace'tracy of the temperature difference between the nomimal meteorological tower elevations of 27 feet and 200 feet be 1 0.2*F (time averaged).

During a routine inspection (semi-annual calibration) of this reguired parameter on April 14, 1984, the accuracy was found to be + 0.36 at 32*F and + 1.45' at 110*F.

Cause The cause of the inconsistency was electronic drift of the 200 foot elevation delta temperature translator card. The magnitude of the electronic drift exceeds the manufacturer's design specifications.

Corrective Action The 200 foot delta temperature translator card was recalibrated to bring the accuracy of the 27 foot and 200 foot temperature difference within the required specification of i 0.2 F. The translator card was recalibrated to a temperature accuracy of i 0.0 at 32*F and 110'F. In addition, the licensee is pursuing the problem of electronic drift of the translator card with the vendor that installed the system and the manufacturer of the equipment.

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r NONROUTINE ENVIRONMENTAL OPERATING REPORT CONTINULD May 14, 1984 Impact The impact of this occurrence is that the actual delta temperature (27 foot to 200 foot) would be less than what the applicable mete-orological instrumentation indicated. This would indicate that atmospheric stability was greater than actually indicated. For dose calculations from accidental gaseous releases to the atmosphere, the effect would be minimal since, by procedure, atmospheric stability is determined using two methods. In the event the two methodologies show different atmospheric stabilities, an alternate method would be utilized.

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