ML20085B498

Discusses Implications of AO on 720507 Re Broken Shoulder Bolt in Plenum of Steam Generator 2.Justification for Removing Reactor Head Challenged

ML20085B498
Person / Time
Site:	Palisades
Issue date:	06/15/1972
From:	Wall H CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Muntzing L US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085B488	List: ML20085B498 ML20085B513 ML20085B521 ML20085B527 ML20085B575 ML20085B598
References
NUDOCS 8307080163
Download: ML20085B498 (2)

Text

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Hany R. Wati

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Vice Chairman of the Board cenerai omces: 212 West Michigan Avenue, Jackson, Michigen 49201. Area Code 617 7 S-C 2  %[

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Fr. L. Manning Muntzing Director of Regulation i

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Dear Mr. Muntzing:

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On May 15 and 16, 1972, Consumers Power Company reported thediscoveryofaportionofa5/8"shoulderboltintheplenumof the No. 2 steam generator at the Palisades Plant. A meeting was held with some of your representatives on May 17. In these reports and this meeting, we concluded that the bolt was one of the upper guide structure ring shim bolts, that these bolts perfom no function during reactor operation, and that there were no significant adverse safety implications involved in the bolt severance.

On May 19, 1972, your Mr. Case sent us a letter stating:

"The location and cause of the recent bolt failure hypothesized in your referenced letter appears to be con-sistent with the known facts. The evidence, however, does not definitely support the conclusion that this is, in fact, an accurate identification of the source of the bolt and of-its failure mode. In view of this, the AEC Regulatory Staff believes that prior to resuming reactor operation, it would be prudent to inspect the upper guide structure and, if necessary, other pressure vessel components to obtain greater assurance that the bolt failure is not symptomatic of some problem, not presently recognized, that might have greater safety significance than the cause of the failure which you have postulated.' In view of this we request that, prior to resuming reactor operation, the pressure vessel head be removed and the upper guide structure and the com-pensating shim ring be inspected. The result of this in- ,4} [ '

spection should be reported to the Directorate of Operations 4 'y; 4 of the AEC, along with your analysis of the suitability of -

the reactor for future operation." /O The reactor head was removed and the reques'ted inspection was made. It confirmed the conclusions stated in our May 15 and 16 reports.

We so reported to your organization by teletype. A further telephone call to Washington was required to obtain clearance for returning the reactor to operation. The plant was out of service for 17 dsys to per-form these actions.

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Mr. L.12.n .irg I.'unt::ing 2 June 15, 1972 We have three principal concerns as a result of this in-cident.

1. The extra outage to inspect the upper guide structure cost Consu::lers Power Company about $1,500,000 for re-placement power. We question the justiff.tation for requesting removal of the reactor head, in the licht of the convincing analysis as to the source of the broken bolt, as well as the absence of safety impli-

, cations associated with such a failure.

2. Personnel were exposed to additional radioactivity due to removal of the head.

3 We believe the record in cases such as this should be made complete by having a " release" in writing as well as the" hold" which stops operation initially.

We would be interested in any comments you may have.

Yours very truly, f c^m" _ _ / 5M Harry . Wall Vice Chairman ,

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