ML19321B262
| ML19321B262 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 07/15/1980 |
| From: | Koch L ILLINOIS POWER CO. |
| To: | |
| References | |
| L14-80(07-15)-9, L14-80(7-15)-9, U-0158, U-158, NUDOCS 8007300429 | |
| Download: ML19321B262 (2) | |
Text
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1 U-0158 L14-80(07-15)-9 ILLINDIS POWER 00MPANY d.N)ti 500 south 27TH STREET, DECATUR. ILUNolS 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 e=erged from investigations performed to date.
These
-include the following-1.
In. late February,- 1980, S&L reported that there had been inadvert-ant use of an incorrect value of soil modulus for the compacted backfill under-th_e,C_PS. Category 1 structures. -
2.
In early March, S&L started to reanalyze the building response spectra.
(The building response spectra are a fundamental con-sideration in analyzing che effect of dynamic ioads, such as earthquake and pool dynamic loads on the piping and equipment.
Note the seismic analyses were not affected by this error.)
~
3.
S&L completed the reanalyses of building response spectra in May.
The results were immediately made available to GE and S&L designers for analyses of their respective scope of supply, i.e., NSSS and BOP equipment and piping.
4.
The dynamic load verification program was interrupted due to this error.
The design verification program is presently continuing.
Although no major design impact is anticipated, it will be some time before the design verification is 0
completed.
8007800
l U-0158 Mr. Jam:c G. Kappler L14-80(07-15)-9 July 15, 1980 Page 2 5.
As a contingency to accommodate possible additional design requirements, the Company has ordered extra snubbers so that untimely new requirements will not interfere with the construc-tion schedule.
6.
Our licensing schedule assumes a 28-month cycle based upon the December 1979 tendering of OL application.
All current 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 expected to be minimal.
However, the reportability determination --
in accordance with the requirements of 10CFR50.55(e) -- will not be possible until all design analyses have been completed.
We.will make this deter =ination at the earliest possible date and close out the matter accordingly.
I trust that this will provide the information you currently need on this subject.
If you have further questions concerning the matter, please do not hesitate to bring then to my attention.
Sincerely, W.
L J. Koch Vice. President cc:
H. H. Livermore, NRC Resident Inspector.
Director, Office of I&E, NRC, Washington, D.C.
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