View source for 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

{{Adams
| number = ML20199H307
| issue date = 01/29/1998
| title = 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
| author name = Sipek J
| author affiliation = ILLINOIS POWER CO.
| addressee name = 
| addressee affiliation = NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
| docket = 05000461
| license number = 
| contact person = 
| document report number = U-602921, NUDOCS 9802050010
| document type = REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER), TEXT-SAFETY REPORT
| page count = 2
}}

=Text=
{{#Wiki_filter:- _ _~.~
   . e+a                                                                                                                      {
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                   !
2 4
Docummt Controf Desk Nuclear Pegulatory Commission                                                                           !
j                        Washir,gton, D.C. 20555 -
c                        

==Subject:==
Special Repost: Inoperability of the 10 Meter and 60-Meter                               ;
;                                       Wind Direction Instrutnentation at Clinton Power Station l
4 i
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 hours on January 13,1998, and                           ;
                        . remained inoperable until 1720 hours 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 hours ou January 13,1998 Operations personnel declared the meteorological tower wind
~
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
h h,kll
              .WRNih[
: w _.
n      U
                                .+.
([

1
    .-  x.                                                                                                                                                 -;
U402921 Pass 2 5
                     <..3                  .
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 hours 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
                                                                                                                \                                              ,
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
b'
                                                          ! ._)
i
                  -._ .7 jy      :sr                                *
                                                     -                           .n_.      -
                                                         . - _ . - - . . . . . .. . . -             - - . . - . - . .      . - -     .- . . - . - . .   ..~}}