ML20084S988
| ML20084S988 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 02/20/1974 |
| From: | Sewell R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8306200364 | |
| Download: ML20084S988 (2) | |
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- j. v uW con...i onic..: 2i2 w..t u.cn.a.n A<enu.. sacw.on, u.cmo n 492oi. Ar.. coo. si7 7se osso February 23, 1974 Mr. John F. O' Leary, Director Re: Docket 50-255 Directorate of Licensing License DPR-20 US Atomic Energy Commission Palisades Plant Washington, DC 205h5
Dear Mr. O' Leary:
This letter is written to inform you of an event which oc-curred at the Palisades Plant on January 6, 1973 which was originally interpreted to be not reportable in accordance with the terms of our operating license. During a recent review by a representative of the Directorate of Regulatory Operations, Region III, our interpreta-tion was disputed and we agreed to report the occurrence in accordance with Section 6.6.le of the Technical Specifications.
Section 6.6.le of the Technical Specifications requires reporting when a control rod is defined as inoperable. On January 6, 1973, CRDM #6 was exercised by withdrawing it slightly to the upper electrical limit (UEL).
Following withdrawal, the operator had diffi-culty driving it in the several inches to its original position. To recitify the problem, an electrician was called in from offsite. He cycled the control relay, after which the CRDM operated normally.
Throughout the period of time beginning when the operator had diffi-culty with CRDM and ending when the electrician cycled the contacts (approximately two hours), the CRDM was never misaligned with the re-mainder of its control rod group. On several other ocassions, similar occurrences have been experienced except that an electrician was imme-diately available at the plant site to cycle the contactor to determine that the CRDM was operable.
The Region III DRO representative questioned our not reporting this in the light of the fact that help was not imme-diately available at the plant site to determine whether it was a problem with a sticking contactor or sluggish brake asseuoly or a truly stuck rod.
We agreed that this interpretation provides more definitive guidance with regard to reportability and that, in the future, we would classify similar occurrences reportable if the necessary skills were not immediately available at the plant site to make an opera-bility determination. We further agreed to reclassify and report this occurrence, which is the purpose of this letter.
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%J Mr. John F. O' Leary, Dir:ctor 2
Docket 50-255, License DPR-20 Palisades Plant February 20, 1974 During the next outage, which commenced mid-January 1973, the CRDM motor was disassembled and inspected. The end play was found to be excessive, which allowed the brake to jam at the upper limit of travel. The excessive end play was corrected and the CRDM operated normally.
This event did not, and future similar events of a similar nature vill not, compromise reactor safety because the CRDM is still capable of being tripped. A failure in the motor package does not prevent proper functioning of the clutch r. nit.
The de-energizing of the clutch separates the motor package from the remainder of the CRDM.
Yours very truly, Ralph B. Sewell (Signed)
RBS/ds Ralph B. Sewell Nuclear Licensing Administrator CC: JGKeppler USAEC F
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