ML20077H967
| ML20077H967 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 08/02/1983 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20077H968 | List: |
| References | |
| 23881, NUDOCS 8308120128 | |
| Download: ML20077H967 (3) | |
Text
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@ Consumers power James W Cook b
Vice President - Projects. Engineering and Construction i
General offices: 1945 West Pernall Road, Jackson, MI 49201 * (517) 78& O453 August 2, 1983 Harold R Denton, Director Office of Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 MIDLAND ENERGY CENTER MIDLAND DOCKET NOS 50-329, 50-330 SEISMIC MARGIN REVIEW REPORT FILE:
B3.7.1 SERIAL: 23881 ENCLOSURE:
VOLUME V - DIESEL GENERATOR BUILDING REVISION 1 (25 Copies)
REFERENCE:
(1) LETTER FROM J W Cook to H R DENTON, SERIAL 22028, DATED APRIL 28, 1983 (2) LETTER FROM J W COOK TO H R DENTON, SERIAL 21010, DATED FEBRUARY 4, 1983 In reference (1), Consumers Power Company submitted Volume V of the Seismic Margin Review Report titled, " Diesel Generator Building" for the Staff's review. Structural Mechanics Associates (SMA), the authors of the report, have identified that incorrect input was used in one of their computer analyses. As a result of this error, the building forces and moments calculated for the Diesel Generator building were affected.
Correspondingly, Revision 1 of Volume V of the Seismic Margin Review Report is resubmitted for the NRC review, using the corrected computer input and incorporating several minor editorial corrections within the text.
I The above-mentioned information was provided earlier to the NRC (M A Miller) by Company personnel during a telephone conversation on July 21, 1983. As noted during that conversation, the incorrect input occurred in the process of i
digitizing the top-of-fill ground response spectra for use in computing the i
building reaction forces. As a consequence, the previously reported seismic margin has been reduced. However, since the digitized ground response spectra is not used to generate in-structure response spectra, the incorrect input did not effect the equipment qualifications presented in Volume VII which was j
transmitted as Attachment 2 in reference (2). SMA has reviewed all other Y}
I applications of digitized ground response spectra, both top-of-fill and oc0783-0533a100 g
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2 original-ground-surface, and has concluded that the use of incorrectly digitized seismic input was limited to the aforementioned application in the Diesel Generator Building.
The reanalysis of the Diesel Generator Building uses the corrected digitized response spectra. The revised seismic responses, which are conservatively estimated, reduced the lowest margin to code allowable from 1.9 to 1.6.
Based on these results, the conclusions made in Attachment 1 of reference (2) on the adequacy of the structure to resist the effects of the Seismic Margin Earthquake per the criteria of the Seismic Margin Review stated in Volume I remain unchanged.
JWC/MFC/bjw CC RJCook, Midland Resident Inspec r
),
JGKeppler, Administrator, NRC Region III DSHood, US NRC FRinaldi, US NRC, (2)
GHarstead, Harstead Engineering MAMiller, US NRC, Licensing Branch No 4 JDKane, US NRC, HGEB i
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f CONSUMERS POWER COMPANY Midland Units 1 and 2 Docket No 50-329, 50-330 Letter Serial 23881 Dated August 2, 1983 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 Revision 1 of Volume V of the Seismic Margin Review Report.
CONSUMERS POWER COMPANY By JW ook, Vice Presiddnt Projec
, EnRineering and Construction l
Sworn and subscribed before me this % day of Ne o<,d//8.
/
G.a, ( A t' Sew Beverly A. Avety Notary P6blic 1
Jackson County, Michigan My Commission Expires 0<
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