ML20064H736

Discusses Questions Raised During Visit Re Diesel Generator Settlement Problem

ML20064H736
Person / Time
Site:	Midland
Issue date:	12/07/1978
From:	Cooke T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Martinez P EMVBECP
References
CSC-3663, NUDOCS 7812260188
Download: ML20064H736 (2)

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Midlead Prmect: P.o. Som 1963, Midland. Machigan 4040. Area Code 517 631-o951 *

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December 7,1978 '

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Mr. P. A. Martinez 4 f_

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Bechtel Power Corporation P.O. Box 1000

• Ann Arbor, MI 48106 MIDLAND PROJECT CWO 7020.- DECEMBER 3 & 4, 1978 NRC VISIT RECARDING DIESEL CENERATOR SETTLEMENT File: B3.0.3 , Serial: CSC-3663 While this is not a set of minutes or an open item action list, during the sub-( ject visit several issues or questions were raised or inferred as noted below: -

1. New settlement readings taken after duct bank freeing would seem to indicate the building may be pivoting about a north-south axis located somewhere in the vicinity of the condensate pipes. This raised a question concerning the potential hard spot developed by the 20," condensate line encased in the 24" lines surrounded ~by concrete and possibly resting on well compacted sand.

If this is the case, we should examine the Diesel Generator Building stru- -

cture in the vicinity for cracks in the concrete and consider the possibility of cutting loose the condensate lines immediately adjacent to the Diesel Generator Building.

2. When Mr. Ferris discussed possible causes, he made the point that it may be impossible to state the exact cause and that the more immediate concern was the remedial action. Although we concur that remedial action is most impor-tant, it should be noted that Mr. Callager took strong issue with this point

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f in that I & E believed cause determination to be mandatory and relative "to

( preclude repetition," etc. This aspect should receive more attention.

3. During this discussion it was noted that instrumentation will show when sur-charge may be removed. In response to the NRC question regarding sane, it was also noted that most settlement should occur rapidly as the area is being preloaded and that total settlement could take weeks or months. Our final response will have to provide sufficient rationale for determination that required netlement has taken place and answer the question of how we arrived

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at what nas required.

4. Bechtel agreed to provide R. Cook a list of the equipment (small hand equip-ment and vibratory rolling equipment) which Bechtel utilized for compacting the fill fract EL 618' to EL 628' iri the Dicsel Generator Building.

5 Durin;, Mr. McConnell's discussion regardin;; Item V, !!r. Calla;;cr questioned the possible interference by the 20" condensa:e line. Bechtel should in- /

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P. A. Martinaz

• . Midland Projset GWO 7020 - Dictmber 3 & 4. 1978

• NRC Visit Rsgarding Diesel Generator Settlement File: B3.0.3 Serial: CSC-3663 December 7,1978 Page 2 l ,

vestigate and document the effects of additional outside pressure on the i

condensate lines resulting from the preload. Again Bechtel should con-sider cutting same at i

this point in time since it appears that it could' be acting as a cantilever type restraint with the fixed end being the -

! Turbine a re a. Building wall and/or the well compacted sands existing in that l In a separate discussion, Mr. Don Miller noted that we have t'o con-sider the effect of rupture of the condensate line and subsequent flooding. '

on a Class I structure during a tornado and/or an earthquake.

6.

Mr. Callager appeared to find Mr. Dahr's explanation connected with VII a . 1),

l table oversite, unacceptable or at least extremely difficult to accept .

Bechtel should be prepared to completely satisfy the NRC concern in this area .

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VII a. 7)unacceptable.

cussion Mr. Ca11ager appeared to find the 12% Industrial Standard dis-NRC concern in this area.Bechtel should be prep ~ ared to completely satisfy the We believe Mr. Callager's question not only re-lates to the characteristics of the proctor curves in terms of optimum mois-

's ture content but additionally whether the material being placed relates to

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the selected validity of yourproctor.

tests;"To go a little further, he may be questioning the i.e., was it really 80% or 95% compaction.

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In my opinion, we should be prepared to fully address Mr. Heller's summary comments regarding the fact that the response to the Diesel Generator Settle-

, ment questions will have to improve or exceed the reviewer's expectations.

i Mr. Heller was discussing the fact that the construction permit was based on the original reviewer's examination of the program, and that licensing vill now have to judge whether or not the codification program meets or exceeds ~

the construction permit intentions and qualifications.

This would seem to indicate that our responses are going to undergo an extremely critical re-view and that none of our answers will be acceptable unless they can with-stand the most intense scrutiny.

part of the operating license hearings.It would also appear that this will become

' In that respect I cannot emphasize too strongly the need argument in our responses. for absolute documented accuracy an,d the strongest i ('" .

. As a separate issue we are also extremely interested in as early as possible resolution to the Turbine Building basement wall problem and preload relative i

of the area between the Turbine Building and the Diesel Cenerator Building, I am submitting this list of items for your review and consideration as part of the overall development No response orthis

~is ,re'qiiiired at resolution time. to the Diesel Generator Settlement probl em.

% 5 A T. C. Cooke Project Superintendent TCC/sd cc: DBMiller JLCorley ABoos

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