ML20052F177

Forwards Effects of Cracks on Serviceability of Structures of Midland Plant. Sealing of Cracks Will Be Performed After Completion of Underpinning Operations

ML20052F177
Person / Time
Site:	Midland
Issue date:	04/30/1982
From:	Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML20052F178	List: ML20052F177 ML20052F187
References
16884, NUDOCS 8205120202
Download: ML20052F177 (2)

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Power Jernes W Cook O Vice President - Projects, Engineering and Construction General offices: 194b West Pernen Road, Jockeon, MI 49201 e (517) 788 0453 April 30, 1982 c9 Y,

Harold R Denton, Director '.$'

Office of Nuclear Reactor Regulation d '

Division of Licensing ~ N, s p US Nuclear Regulatory Commission -

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MIDLAND PROJECT MIDLAND DOCKET NO 50-329, 50-330

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Y EFFECTS OF CRACKS ON SERVICEABILITY OF CONCRETE STRUCTURES AND REPAIR OF CRACKS FILE: 0485.16 SERIAL: 16884

REFERENCES:

(1) J W COOK LETTER TO H R DENTON, EVALUATION OF FEEDWATER ISOLATION VALVE PITS AT MIDLAND PLANT, SERIAL 15493, DATED JANUARY 25, 1982 (2) J W COOK LETTER TO H R DENTON, EVALUATION OF AUXILIARY BUILDING CONTROL TOWER AND ELECTRICAL PENETRATION AREAS AT MIDLAND PLANT, SERIAL 15527, DATED JANUARY 29, 1982 (3) J W COOK LETTER TO H R DENTON, EVALUATION OF THE EFFECT ON STRUCTURAL STRENGTH OF CRACKS IN THE WALLS OF THE DIESEL GENERATOR BUILDING, SERIAL 15978, DATED FEBRUARY 16, 1982 (4) J W COOK LETTER TO H R DENTON, EVALUATION OF CRACKING IN SERVICE WATER PUMP STRUCTURE AT MIDLAND PLANT, SERIAL 16009, DATED MARCH 2, 1982 ENCLOSUPE: EFFECTS OF CRACKS ON SERVICEABILITY OF STRUCTURES AT MIDLAND PLANT References 1 through 4 above transmitted a series of reports which presented an evaluation of the effect on structural strength of cracks observed in the feedwater isolation valve pits, the auxiliary building control tower and electrical penetration areas, the diesel generator building, and the service water pump structure. These four reports were provided as the result of discussions with the NRC Staff and its consultants at meetings held on December 10, 1981 and January 11, 1982. During these meetings, Consumers Power agreed to provide the NRC with an evaluation of the effects of cracks on the longterm serviceability of conc. rete structures and with recommendations on the sealing of cracks.

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1 In response to this' commitment, we are providing the enclosed report entitled,

" Effects of Cracks on Serviceability of Structures at Midland Plant," by Messrs W G Corley, A E Fiorato and D C Stark of Construction Technology j[

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Laboratories, a division of the Portland Cement Association. This report contains_ a discussion of the effects of observed cracks on the serviceability of the feedwater isolation valve pits, the auxiliary building, the diesel generator building and the service water pump structure and provides our recommendations for the sealing of cracks in these structures. Please note that the enclosed report does not apply to the borated water storage tank foundations. The repair of cracks by pressure grouting of the borated water storage tank foundations has been addressed in a seperate 50.55(e) report forwarded to the NRC by our recent correspondence, Serial 16172, dated April 23, 1982.

Based on the conclusions reached in the enclosed report we wish to recommend-the following: (1) sealing of cracks in walls by epoxy injection for cracks above the permanent water table is considered unnecessary; (2) sealing of cracks by means of epoxy injection or other means for walls below the permanent water table, which show visible leakage of water, will be performed; and (3) the south wall of the service water pump structure will be coated on ihe exterior surface within the splash zone area adjacent to the cooling pond, f.e., between Elevation 626' and Elevation 637.5'. The epoxy injections can be applied from the interior surface. We are also advising that the work to seal cracks will be performed af ter completion of the underpinning operations.

JWC/RLT/FV/mkh CC Atomic Safety and Licensing Appeal Board, W/o CBechhoefer, ASLB, w/o HMCherry, Esq, w/o FPCowan, ASLB, w/o RJCook, Midland Resident Inspector, .w/o RSDecker, ASLB, w/o SGadler, w/o JHarbour, ASLB, w/o CHarstead, Harstead Engineering, w/a DSHood, NRC, w/a (2)

DFJudd, B&W, w/o JDKane, NRC, w/a FJKelley, Esq, w/o RBLandsman, NRC Region III, w/a WHMarshall, w/o JPMatra, Naval Surface Weapons Center, w/a W0tto, Army Corps of Engineers, w/o WDPaton, Esq, w/o SJPoulos, Geotechnical Engineers, w/a FRinaldi, NRC, w/a HSingh, Army Corps of Engineers, w/a BStamiris, w/o oc0482-0085a100