ML20085D824

Special Rept 91-04:on 910927,red Indication Values Received on Wind Direction Instrumentation Computer Screen.On 911004, Discovered That Wind Direction Recorder Inoperable Since 910923.Wind Direction Transmitter Replaced

ML20085D824
Person / Time
Site:	Callaway
Issue date:	10/09/1991
From:	Blosser J, Taylor M UNION ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
91-04, 91-4, ULNRC-2497, NUDOCS 9110170189
Download: ML20085D824 (3)

Text

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October 9, 1991 l U. S. Nuclear Regulatarv Commissica Document Control Desl<

Washington, DC 20 % 5 UlSRC-2497 Cont 1 arte 1:

DOCKET NUMBER 50-483 CALIAWAY FIANT UNIT 1 FACILITY OPERATING LICENSE NPF-30 SPECIAL REPORT 91-04 60 METi.R VIND DIRECTION INSTRUMENTATION INOPERABLE FOR GREATER TilAN 7 DAYS DUE TO A BLOWN FUSE This Special Report is submitted in accordance with Technical Specification 3.3.3,'6 actAon uratement (a). The 60 meter wind direction instrumentation was inoperable for more than 7 days due to a blown fuse to the wind direction trar.smitter.

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/E J . D. Bloss-i-Manager, Callaway Plant JDB/ ' /MNF/Irj cc- Distribution attached

' 9119170189 911009

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. k%Iiry AcJress: PO Bnx 620, foton, MO ffEI

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-ec distribution for UI.NRC 2497 Mr, A'.-Bert Da'els 'Mr. M. David L /nch (2 copies) ,

Regional Administrator' U.S. Nuc1 car _Rugulatory Commission U.S; Nuclear ;1egulatory Commission OWFN - tiall Stop 13E21 Region III_ _ Washington D.C 20555 ,

799 Roosavelt Road G'.en ' Ellyn, I L 60137 Manager, Electrie Department Mr. liarold I;. Che.noff Missouri Public Service Commission Supervisor Licensing P.O. Box 360 Wolf Creek Nuclear 0;) crating Corp.

Jefferson City, MO 65102 P. O. Box 411 Burlington, Kar sas 66839 Records Center Mr. - R. L. llague Institute of Nuclear Power Operations Chief . Project Section 3C Suite 1500 U.S. Nuclear Regulatory Commission '

1100 circle 75 Parkway Region III-Atlanta, CA 30339 799 Roosevelt Road Glen Ellyn, IL 60137 NRC Senior Resident Inspector W

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GPECIAL REPORT 91-04' 60' METER VIND DIRECTION INSTRUMENTATION INOPERABLE FOR GREATER TlisN 7 DAYS DUE TO A Bl.0VN FUB This:roport is submitted in .tecordance with Tn:hnical Specification 3,3.3.4 action statement (a) which states: "With one or more required meteorological monitoring channels inoperable for more than 7 days, prepare and submit a Specini Report to the Ccmmission pursuant to Specification 6.9.2 within the next_cen days outlining tho cause of the malfunction and the plans for restoring the channel (s) to OPEMBhE status. "

OnL9/27/91, at approximately 0100-CDT, a licensed reactor __ operator. selected the Meteorological Tower Data computer screeo ind logged that the-10 meter and 60 meter wind direction values were shown in red rather than the normal green, lie compared this screen with a group dl splay screen of- the came parameters which showed the word " good" adjace it to the values. He discussed the condition with other licensed oparators on his crew. They concluded " good" meant the sensor was operatire and- they attributed the red indication values to a wind variation between the 10 meter and 60 meter elevations.1There have been similar.. previous red indications associated

.with calm . (r.o wind) weather cor.ditions . P on 10/4/91~ at 1026, a utility Instrun:entation and Controls technician discovered the condition during monthly preventive maintenance on the 60 ,

meter wind direction recorder lie initiated a repair work -request. His l investigation of the recorder printout revealed the channel was inope'rable  !

since 9/23/91 at 0700 as evidenced.by a contiruous reading at 359 degrees.

On 10/5/91 at 1239; the1 damaged wind direction t:cansmitter was replaced, retested and the 60-meter wind-direction instiumont was declared operable.

d-The transmitter had failed-due to a blown fust

' Enhancements to the operator's logs will improve the. channel check criteria to ensure timely diutovery of a similar condition.

1 This di6_ nat pose a potential concern for any dose _ proj ection c alculations -

which may hast been performed during the period of the 60 meter wind direction inop.vab).11ty. The invalid wind dire ction signal would have provey+.ed th6 idGmatic modeling do e calculation _ at 60 meters, Plant procedures And backup wind direction indication at 90 and 10 meterr would-have led to corrtet dose calculations if they had been required.

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