ML19209B764
| ML19209B764 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 09/04/1979 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Glamann D AFFILIATION NOT ASSIGNED |
| References | |
| NUDOCS 7910100408 | |
| Download: ML19209B764 (2) | |
Text
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UNITED STATES NUCLEAR REGULATOP.Y COMMISSION y
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SEP 4193 Occket No: STN 50-482 Mr. Daryl G1amann 130 North Bebe Street Wichita, Kansas 67212
Dear Mr. Glamann:
Your letter of June 27, 1979, to Mr. Harold Denton, concerning the concrete in the base mat at Wolf Creek, has been referred to me for a reply.
In your letter, you make coments about the quality and strength of the concrete.
The matter of the concrete strength of the Wolf Creek base mat dealt with the fact that the results of tests performed on the concrete at 90 days indicated that some of the concrete batches had strengths of less than the 5,000 pounds per square inch value specified by the architect-engineer to meet the design criteria in the Wolf Creek Preliminary Safety Analysis Report (PSAR).
In some cases, the results of the 90-day tests were lowr than the results of the 28-day tests.
As a result of the above situation, the Kansas Gas & Electric Company (the lead applicant for the Wolf Creek plant) had a number of strength tests and petro-graphic analyses performed on the concrete samples originally tested at 28 Jays and 90 days to detemine the cause of the situation and to determine li the ct.,
crete was becoming weaker with time. The applicant concluded that the results of these tests and analyses indicated no signs of sub-stardard concrete, inade-quate mixing or adverse chemical reaction, or that the concrete was getting...
weaker with time.
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At our request, an independent petrographic analysis was also perfomed on the concrete samples 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 perfomed a reanalysis of the base mat, at our request, to detemine if the indicated strength of the concrete based on the 90-day test re?ults would satisfy the design criteria specified in the Wolf Creek PSAR. The applicant calculated this strength to be 4,460 pounds per scuare inch as compared to the 5,000 pounds per square inch value originially specified by the architect-engineer. The applicant then performed a reanalysis of the base mat based On a concrete strength of 4,460 pounds per square incn to demonstrate that the design criteria in the PSAR were met.
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. Sgp 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 document, dated July 12, 1979. A copy of this document is enclosed for your information. As stated in the document, we conclude that the base mat concrete strength has not retrogressed, that the strength of the base mat meets the original design criteria in the Wolf Creek PSAR, and that the mat will withsthnd the specified design loads and loading combinations without impairment of its structural integrity or its safety function.
I am pleased to have had this opportunity to respond to your comments.
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. N[r ting Assistant Director v
for Light Wate Reactors Division of Proj' t Management
Enclosure:
As stated 1139 140 2..
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