ML20079G176

Forwards Response to NRC Request for settlement-related Analyses for Diesel Generator Bldg, Structural Stresses Induced by Differential Settlement of Diesel Generator Bldg

ML20079G176
Person / Time
Site:	Midland
Issue date:	06/01/1982
From:	Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML20079G179	List: ML20079G176 ML20079G186
References
1722B, NUDOCS 8206080340
Download: ML20079G176 (3)

Text

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• ,e Consumers '

POVrer James W Cook O Vice President - Projects, Engineering and Construction General offices: 1945 West PernsH Road, Jockeon, MI 49201 e (517) 788-0453 June 1, 1982 liarold R Denton, Director Office of Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 MIDLAND PROJECT MIDLAND DOCKET NO 50-329, 50-330 RESPONSE TO TIIE NRC STAFF REQUEST FOR SETTLEMENT-RELATED ANALYSES FOR THE DIESEL GENERATOR BUILDING FILE: 0485.16, B3.0.3 SERIAL: 17228 ENCLOSURE: (1) STRUCTURAL STRESSES INDUCED BY DIFFERENTIAL SETTLEMENT OF THE DIESEL GENERATOR BUILDING As a result of meetings with the NRC during the week of February 23-26, 1982, a number of analyses were completed to resolve concerns identified by the Staff for the diesel generator building. These analyses included:

(1) analysis of the diesel generator building, including the effect of settlements which occurred before the removal of the surcharge; (2) statistical evaluation of the diesel generator building settlement data to support the conclusion that the structure is settling as a rigid body; and (3) analysis of the diesel generator building using zero springs and/or reduced spring values.

The diesel generator building was analyzed as documented in the technical report for the governing loading contributions including the effects of the surveyed settlements recorded from the start of construction (6-6-78) to the removal of surcharge (8-3-79), and also for the ef fect of the predicted forty-year settlement. The maximum rehar stresses are within the allowable of 54 ksi and are, therefore, within the strength capacity of the building to withstand the design loads specified in the FSAR and Question 15 of the NRC Requests Regarding Plant Fill.

In Attachment I-1 of the technical report the statistical evaluation of the surveyed settlement data verifies that the data contains both systematic and erratic errors due to optical surveys at different elevations due to the inaccessibility of permanent markers during the surcharge. This data lends ,

further support to our conclusion that the diesel generator building is o )([)

g l undergoing rigid body motion. O I (

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2 In Attachment I-2 of the technical report the potential bridging of the building over soft soils was also analyzed and by comparison with the original design analysis it is concluded that the structure will withstand the stresses of this hypothesis.

We believe these analyses represent a complete response to the concerns identified by the Staff and the enclosed technical report completes the analytical activities associated with the diesel generator building.

wMll{ \'b U' g g, ND JWC/WJC/mkh CC Atomic Safety and Licensing Appeal Board, w/o CBechhoefer, ASLB, w/o MMCherry, Esq, w/o FPCowan, ASLB, w/o RJCook, Midland Resident Inspector, w/o RSDecker, ASLB, w/o SGadler, w/o JHarbour, ASLB, w/o GHarstead, 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 oc0582-0093a100

l CONSUMERS POWER COMPANY Midland Units 1 and 2 Docket No 50-329, 50-330 Letter Serial 17228 Dated June 1,1982 At the request of the Commission and pursuant to-the Atomic Energy Act of 1954, and the Energy Reorganization Act of 1974, as amended and the Commission's Rules and Regulations thereunder, Consumers Power Company submits the Response to the NRC Staff Request for Settlement-Related Analyses for the Diesel Generator Building.

CONSUMERS POWER COMPANY By b YJ R B DeWitt, Vice President Nuclear Operations Sworn and Subscribed Before Me This d4 Day of her& f>

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bru<le deu,- Beverly A. Avery

/ NotaryfPublic Jackson County, Michigan My Commission Expires h% /4 /fd '

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