ML19344E539
| ML19344E539 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 08/01/1980 |
| From: | Fiorelli G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Gerstner W ILLINOIS POWER CO. |
| References | |
| NUDOCS 8009020188 | |
| Download: ML19344E539 (1) | |
Text
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NUCLEAR REGULATORY COMMISSION TfC
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799 ROOSEVELT ROAD e
GLEN ELLYN, ILLINOIS 60137 o
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I 1980' Docket No. 50-461 Illinois Power Company ATTN: Mr. W. C. Gerstner Executive Vice President' 500 South 27th Street Decatur, IL 62525 Gentlemen:
Thank you for your interim report dated July 15, 1980, pursuant to 10 CFR 50.55(e) regarding status of investigations of S&L soil characteristics We will review your final report on this matter upon receipt.
error.
Your cooperation with us is appreciated.
Sincerely, G. Fiorelli, Chief Reactor Construction and Engineering Support Branch cc: DirecLor, RCI/IE Director, AE0D Chief, OEB/MPA IE Files cc w/1tr dtd 7/15/80:
Central Files PDR Local PDR NSIC TIC Mr. Dean Hansell, Office of Assistant Attorney General Mr. Gary N. Wright, Chief Division of Nuclear Safety i-f 8009020 \\%T
U-0158 L14-80(07-15)-9 f
ILLINDIS POWER COMPANY y,
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500 SOUTH 27TH STREET, DECATUR, ILLINOIS 62525 July 15, 1980 Mr. James G. Keppler Director, Region III Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
Clinton Power Station Unit 1 Docket No. 50-461 Construction Permit CPPR-137 The purpose of this letter is to respond to Mr. H. Wescott's request for further information regarding the status of our investigations of the S&L soil characteristics error in Clinton Power Station design.
Region III was first notified of a potential 10CFR50.55(e) reportable deficiency by telephone on February 29, 1980.
Subsequently, Region III was advised by letter dated March 31, 1980, that there was insufficient information to make a determination of reportability.
It was also stated that we would continue our investigation of the error and keep you apprised of progress.
Although a reportability determination is not yet possible, a number of facts have emerged from investigations performed to date.
These include the following:
In late February, 1980, S&L reported that there had been inadvert-1.
ant use of an incorrect value of soil modulus for the compacted backfill under the CPS Category 1 structures.
In early March, S&L started to reanalyze the building response 2.
(The building response spectra are a fundamental con-spectra.
sideration in analyzing the effect of dynamic loads, such as earthquake and pool dynamic loads on the piping and equipment.
Note the seismic analyses were not affected by this error.)
S&L completed the reanalyses of building response spectra in 3.
The results were immediately made available to GE and May.
S&L designers for analyses of their respective scope of supply, i.e., NSSS and BOP equipment and piping.
The dynamic load verification program was interrupted due to 4.
The design verification program is presently this error.
Although no major design impact is anticipated, continuing.
it will be some time before the design verification is completed.
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U-0158 Ll4-80(07-15)-9
' Mr. Jam 00 G. Kapplor July 15, 1980' Page 2
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As a contingency to accommodate possible additional design requirements, the Company has ordered extra snubbers'so that 5.
I untimely new requirements will not interfere with the construc-tion schedule.
Our licensing schedule assumes a 28-month cycle based upon 6.
All current the December 1979 tendering of OL application, analyses are expected to be completed within that time to demonstrate compliance with the design bases.
The net impact of the S&L soils design error on CPS design is However, the reportability determination --
expected to be minimal.
-- will not be in accordance with the requirements of 10CFR50.55(e)
We will possible until all design analyses have been completed.
make this determination at the earliest possible date and close out the matter accordingly.
I trust that this will provide the information you currently need If you have further questions concerning the matter, on this subject.
please do not hesitate to bring them to my attention.
Sincerely,
/
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L J. Koch Vice President H. Livermore, NRC Resident Inspector H.Director, Office of I&E, NRC, Washington, D.C.
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