U-602921, Special Rept:On 980113,operations Personnel Declared Meteorological Tower Wind Direction Instrumentation Inoperable.Consistent Difference Suspected to Have Been Caused by Rotation of Either or Both of Wind Sensor

Special Rept:On 980113,operations Personnel Declared Meteorological Tower Wind Direction Instrumentation Inoperable.Consistent Difference Suspected to Have Been Caused by Rotation of Either or Both of Wind Sensor

ML20199H307
Person / Time
Site:	Clinton
Issue date:	01/29/1998
From:	Sipek J ILLINOIS POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
U-602921, NUDOCS 9802050010
Download: ML20199H307 (2)

Text

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i innes Power Company .j CIWM Power Staton >

P o Dox 678 l Clinton. IL 61727  !

-I Tel 217 v35 6489 l Joseph V. $1pek R o~o' "*"a e . cm.' U402921 SE.100c January 29, 1998 l Docket No. 50 461 10CFR50.36  !

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Docummt Controf Desk Nuclear Pegulatory Commission  !

j Washir,gton, D.C. 20555 -

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Subject:

Special Repost: Inoperability of the 10 Meter and 60-Meter  ;

Wind Direction Instrutnentation at Clinton Power Station l

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Deer Madam or Sir:

l Clinton Power Station (CPS)_ Operational Reqvfrements Manual (ORM) Action r 3.2.8 requires inoperabilities of meteorological monitoring instrumentation channels for more than 7 days be reported to the NRC within the next 10 days pursuant to ORM i

Section 6.9.2, SPECIAL REPORTS.--The 10 meter and 60 maer wind speed instrumentation was declared inoperable at 0714 hours0.00826 days <br />0.198 hours <br />0.00118 weeks <br />2.71677e-4 months <br /> on January 13,1998, and  ;

. remained inoperable until 1720 hours0.0199 days <br />0.478 hours <br />0.00284 weeks <br />6.5446e-4 months <br /> on January 24,1998. This report is being

' - submitted in accordance with the CPS ORM to provide information regarding the  ;

extended inoperability of the meteorological monitoring instmmentation.

The CPS Environmental Monitoring system utilizes a 199 foot high tower 4 equipped with two levels ofinstrumentation to monitor the meteorological conditions at the plante The tower is instmmented with wind direction, wind speed, temperature, and -

dew point sensors at the 10-meter and 60-meter levels (except that dew point is monitored at the 10 meter elevation only). As described above, at 0714 hours0.00826 days <br />0.198 hours <br />0.00118 weeks <br />2.71677e-4 months <br /> ou January 13,1998 Operations personnel declared the meteorological tower wind

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direction instmmentation inoperable since the recorded wind direction was a constant value (6e., the minor sarlations in wind direction that normally occur were not evident) ,

for both elevations; Freezing rain was suspected to have caused icing of the instmments

such that it prevented free motion of the detectors. A visual inspection of the

- meteoro'4gical tower from ground level performed by the 1,ystem engineer on January

• l 15,1998, showed that there was, in fact, an ice buildup on the both of the wind direction vanes as evidenced by the lack of a perceptible response to minor fluctuations  !

in wind direction that were occurring at the tim O s

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A review of the wind direction data showed that aAer this problem was identified, j there was a period of several hours where the 10-meter and 60-meter wind direction  ;

Instmments began tracking again. However, following the initial apparent ice-bound j condition, the data from the 10 meter and 60 meter wind direction instmments _i i consistently differed by approximately 30 degrees. This consistent diff'erence was  !

suspected to have been caused by rotation of either or both of the wind sensor housings j occurrir3 ering d the preceding periods of high winds and freezing rain. t c When weather conditions permitted, C&I personnel worked expeditiously to retum the meteorological !oww wind direction instmmentation to service. On January 21,

- 1998, technicians climbed the meteorological tower and verified that there were no poblems with the 10-meter wind direction instmment and that it was reading correctly.  !

On h,nuary 22,1998, technicians climbed the tower to the 60-meter. wind direction

. Instmment, The problem with the 60 meter wind direction instmment was determined to-  !

i be that the securing bolt was loose enough to allow slight movement of the housing. The housing we correctly sligned and the securing bolt was tightened. Testing subsequently  ;

- domenstrata that the 60 meter wind direction instrumentation was working correctly and .-

o - there was no longer a disparity between the 10 meter and 60-meter wind direction i instrumentatlon.' The 10-meter and 60 mett and direction instruments were subsequently declared OPERABLE at 1720 hours0.0199 days <br />0.478 hours <br />0.00284 weeks <br />6.5446e-4 months <br /> cn January 24,1998, l

' Submittal of this letter satisfies the requirements of CPS ORM 3.2.8 and ORM .

.6,9.2 for suboitting a SPECIAL REPORT for meteorological tower inoperabilities. i Sincerely yours, i

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J ep V,  !

rector-Licensing

. JFK/krk cc: - Regional Administrator, Region 111, USNRC ,

_ NRC Clinton Licensing Project Manager j NRC Resident Office, %690

~ lilinois Denartment'of Nuclear Safety j i

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