ML20091P794

Special Rept:On 920117,wide-range Noble Gas Stack Monitor RM-063M for post-accident Monitoring Declared Inoperable & Not Returned to Operable Status within 7 Days.Caused by Faulty Mechanical Switch.Maint Work Order Issued

ML20091P794
Person / Time
Site:	Fort Calhoun
Issue date:	01/28/1992
From:	Gates W OMAHA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LIC-92-050S, LIC-92-50S, NUDOCS 9202040028
Download: ML20091P794 (2)

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Omaha Public Power District 444 South 16th Street Mall Omaha, Nebra:ka 8102-2247 402/63& 2000 Januaq 28, 1992 LIC 92-050S U. S. Regulatory Commission Attention: Lbcument Control Desk Mail Station: P14 137 Washington, DC 20555

Reference:

Dr.ckat No. 50-285 Gentlemen:

SUBJECT:

Special Report on Inoperability of Wide Ranga lloble Gas Stack Monitor RM-063M for Post-Accident Monitoring The Omaha Public Power District (OPPD), holder of Operating License PPR 40, submits this report pursuant to the requirements of fort Calhoun Station (FC )

Technical Specification 2.21, " Post Accident Monitorit.g lustrimiitation".

Technical Specification 2.21, Table 2-10, item 2 requires that a minit im of one channel for each uists range noble be operable in Modes 1, 2, and 3. gasIfstack monitor RM the number 0631.,

of oper atirRM-063M channels..id is RM-063H less than the minimum operable channels requirement, OPPD must e".her restore thq inoperable channels to operable status within seven days of the event, or prepare and submit a special report to the Comnission pursm.t to Tecinical Sprificai f an 5.9.3 within 14 days following the event.

On January 17, 1992, at 1425 hours0.0165 days <br />0.396 hours <br />0.00236 weeks <br />5.422125e-4 months <br /> with FCS operating in t. ode 1 at 86 neicent power, RM-063M was declared inoperable because tha rud.stion 'r9nitor d j r.9t meet the daily channel check requirements. With the mode switch in "Cilibrate", the RM-063M rate meter indication did not move to the " Cal ma k. This itoperable condition was attributed to electronic drift.

RM-063M was initially declared operrble tjecause the problem wa.: felt to be only i with the mechanical switch since the meter would sometimes ge tc the " Cal' position, but not consistently. Only upon tioubleshooting was it determined to be more than a switch problem. Thus, previous Daily Operational Surveillance Test Records were reviewed and bared or, the results of the previous channel checks, the RM-063M inoperable status was backdated to 2254 hours0.0261 days <br />0.626 hours <br />0.00373 weeks <br />8.57647e-4 months <br /> on January 14, 1992.

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, The Maintenance Work Order to perform corrective action was issued and an electronic adjustment restored RM-063M to an operable condition. Thus, RM-063M was returned to service and the Limiting Condition for Operation (LCO) was exited on January 22, 1992, at 1536 hours0.0178 days <br />0.427 hours <br />0.00254 weeks <br />5.84448e-4 months <br />.

Upon declaring RM-063M inoperable, the a;plicable Technical Specifications (TS) were reviewed. in accordance with TS Ta>le 2 10, footnote (a), a preplanned alternate method of monitoring the appropriate parameter was verified in place (i.e, normal-ran sampilng existed)ge stack monitors were operational and alternate methods for If you should _ have any questions, please contact me.

Sincerely, AV. Y,/../

W. G. Gates Division Manager Nuclear Operations WGG/lah c: LeBoef, Lamb, Leiby & MacRae 1 R. D. Martin, NRC Regional Administrator D. L. Wigginton, NRC Senior Project Manager R. P. Mullikin, NRC Senior Resident inspector

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