ML20238B306
| ML20238B306 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 08/21/1987 |
| From: | Diederich G COMMONWEALTH EDISON CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 8709010160 | |
| Download: ML20238B306 (1) | |
Text
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Dme O Telephone 815/357-6761 Comm:nwrith Edison LaSalle County Nuclear Station PRIOR!Ty no m p Rural Route #1, Box 220 1
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Marseilles. lllinois 61341
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WN August 21, 1987 i
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Mr. A. Bert Davis I
Region III Administrator
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l U.S. Nuclear Regulatory Commission j
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Dear Sir:
This Special Report is being submitted in accordance with LaSalle Unit 1 Operating License NPF-ll, Appendix A and LaSalle Unit 2 Operating License NpF-18, Appendix A, Technical Specification Table 3.3.7.5-1 and 6.6.c.
On August 14, 1987, at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, with Unit 1 in Refuel and Unit 2 in Run Mode at 99% power, Standby Gas Treatment (SBGT) Wide Range Gas Monitor (WRGM) l Hi Range failed, due to random and spurious spikes, and was declared inoperable.
In accordance with Technical Specification Table 3.3.7.5-1 Action Statement 81, an alternate method of monitoring appropriate parameters must be initiated within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the time of the event. Radiation / Chemistry Department was immediately notified and at 1025 hours0.0119 days <br />0.285 hours <br />0.00169 weeks <br />3.900125e-4 months <br /> on August 14 the alternate means of monitoring appropriate parameters was placed in service.
The hi range detector and power supply were replaced and the preamplifier connectors cleaned. The detector was placed back in service, but not l
considered operable, for observation.
After another spike was received, it was determined that the detector and the power supply was not the cause of the spiking, so the original detector and power supply was placed back into the SBGT WRGM Hi Range. The circuit cards were cleaned and insured to be properly fitted.
At this time, the SBGT WRGM Hi Range is back in service, but not considered operable, for observation. The exact cause for the spiking is still unknown at this time. A supplement to this special Report will be issued when the exact cause is determined and corrective actions taken. The alternate method of monitoring the appropriate parameters will continue until the SBGT WRGM Hi Range is declared operable.
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G. J. Diederich g
Station Manager LaSalle County Station l
GJD/DRR/kg xc: Nuclear Licensing Administrator
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U.S. NRC Document Control Desk NRC Resident Inspector j Q g4%
INPO Records Center i
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