ML20135E484
| ML20135E484 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/03/1985 |
| From: | Diederich G COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 8509160412 | |
| Download: ML20135E484 (1) | |
Text
thh Comm:nwrith Edison LaSalle County Nuclear Station Rural Route #1, Box 220 Marseilles, Illinois 61341 Telephone 815/357-6761 September 3, 1985 PRIcRiry RcuTING EiLU
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Regional Administrator
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{M Mr. James G. Keppler u
Region III FILE # V U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
This special report is submitted in accordance with LaSalle Unit 2 Operating License UPF-18, Appendix A, Technical Specification 3.3.7.12 and 6.6.c.
On July 29, 1985, at 1027 hours0.0119 days <br />0.285 hours <br />0.0017 weeks <br />3.907735e-4 months <br /> with the reactor in Mode 1 at 95% power, Loose Parts Monitor Channel #h was declared inoperable.
The cause of inoperability of Channel #4 results from intermittent operation of the channel components within the dryvell. This was locally proven at the 2PA15J panel.
Channel #h is located at 0, approximately three feet underneath the reactor vessel mounted on a CRD (Control Rod Drive) housing. The Loose Parts Monitoring system is designed to locate sensors at natural collection regions of the reactor vessel. Channel #1 at 90, Channel #2 at 180 and Channel #3 at 270 were operable at the time of the occurrence. The three operable redundant channels would have detected a loose part if it was present at the bottom of the reactor vessel.
Work Request Lh9169 was written to troubleshoot and correct the protlem. Trouble-shooting at the 2PA15J panel proved that the problem was in the dryvell.
Further troubleshooting vill be completed at a cold shutdown outage of sufficient duration. All work completion vill be tracked under AIR 37h-200-85-c0143.
Secondly, LAP-2h0-6 (Temporary System Change) 994-85 was used to clear the false Control Room alarm so the other 11 operable channels will not be masked.
G. J. Diederich f
Str. tion Manager LaSalle County Station GJD/JPP/DRR/kg xc: NRC Resident Inspector INPO - Records Center US NRC Document Control Desk 9 1985 8509160412 850903 PDR ADOCK 05000374 S
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