ML19253B265
| ML19253B265 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 09/04/1979 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Hines D AFFILIATION NOT ASSIGNED |
| References | |
| NUDOCS 7910100525 | |
| Download: ML19253B265 (2) | |
Text
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4 UNITED STATES NUCLEAR REGULATORY COMMISSION
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/.E WASHINGTON. D. C. 20555
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SEP 4 1979 Docket No:
STN 50-482 Mr. David Hines 1335 Wilbur Wichita, Kansas 67212
Dear Mr. Hines:
Ycur mailgram of June 27, 1979, to Mr. Harold Denten, concerning the concrete in the base mat at Wolf Creek, has been referred to me for a reply.
In your mail-gram, you raise questions on the concrete regarding the difference between the 28-day and 90-day test results and the strength requirements, and request an in-dependent study on the matter.
As ycu note, scme of the 90-day tests performed on the Wolf Creek base mat concrete, reWited in lower strengths than those obtained with the 28-day tests.
Therefore, in order to detemine if the concrete was becoming weater with time, the Kansas Gas & Electric Cc apany (the lead a.pplicant for the Wolf Creek plant) had a nuder of strength tests and petrographic aralyses performed on the concrete samples originally tested at 28 days and 90 days. The applicant concluded that the results of these tests and analyses indi::ated no signs of inadequate mixing or adverse chemical reactions, or that the concrete was getting weaker with time.
At our request, an independent petrographic analysis was also performed by the U.S. Army Corps of Engineers. The results of the analysis performed by the Corps of Engineers agreed with the applicant's results.
Additionally, the applicant performed a reanalysis of the base mat, at our request, to determine if the indicated strength of the concrete based cn the 90-day test results would satisfy the design criteria specified in the Wolf Creek Preliminary Safety Analysis Report (PSAR). The applicant calculated this strength to be 4,450 ?cunds per square inch as compared to the 5,000 pcunds per scuare inch value which was originally specified by the architect-engineer to meet the design criteria in the Wolf Creek PSAR.
The applicant then performed a reanalysis cf the base mat on a concrete strength of 4,460 pcunds per scuare inch to demonstrate that the design criteria in the PSAR were met.
1124 045 8910100Spg/$
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SEP 4 1979 We have performed an evaluation of the Wolf Creek base mat, including the tests and analyses discussed above. The results of our evaluation were issued in a docunent, dated July 12, 1979. A copy of this dccument is enclosed for ycur information. As stated in the document, we conclude that the bcse mat concrete strength tas not retrogressed that the strength of the base mat mect? th; original design criteria in the Wolf Creek PSAR, and that the mat will withstand the specified design loads and Toading combinations without impairment of its :truc-tural integrity or its safety function.
I am pleased to have had this opportunity to respond tc your questions and your request.
Sincerely, i
b
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M a
, Steve Yga,Ac ;' inh Assistant Director n.
for '_ight Water Rj-actors Divisi.n of Project Management
Enclosure:
As stated 1124 046