ML19324A047

Forwards Const Technology Labs WR Waugh Basemat Concrete Testing Program, Supporting Util Contention That Basemat Concrete Is Uniform & of High Quality W/Actual in Situ Strength Exceeding 5,000 Psi

ML19324A047
Person / Time
Site:	Wolf Creek
Issue date:	10/26/1979
From:	Koester G KANSAS GAS & ELECTRIC CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19324A048	List: ML19324A047 ML19324A050
References
NUDOCS 8006200144
Download: ML19324A047 (2)

Text

. *

. . PDR

' LPDR TIC V KANSAS GAS AND ELEc NS1C CENTRAL FILES

== m amme a===.-

otenu 6.accstc=

wiCE persectaer optmateoses October 26, 1979 Mr. Karl V. Seyfrit Director, Region IV Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76012 Re Docket No. STN 50-482 Subj: Wolf Creek Reactor Building Base Mat

Dear Mr. Seyfrit:

In accordance with a commitment made to the NRC during our meeting on March 15, 1979, please find attached a copy of Portland Cement Asso-clation (PCA) Report dated September 24, 1979. This report contains the results of a field inves'tigation program described in my letter to you dated February 28, 1979. The program involved a duplication of the basemat concrete batching and test cylinder preparation operations, except that rigid molds were used to cast cylinders in place of flexible molds; and, the newly cast cylinders were not temporarily stored in the field prior to being transported to the QC lab curing room. The test cylinders were capped by PCA using the same type compound utilized on the base mat cylinders, and then tested by PCA on their test machine.

Results of this investigation show that:

l a) The mix design, materials, and batch plant will produce '

concrete exhibiting an average strength of 6096 psi at 90 days with a standard deviation of 286 p:1. This is more than adequate to meet the technical specification requirement of 5000 psi; b) The computed coefficient of variation of 4.70 indicates that the batch plant and materials are capable of pro-ducing very uniform concrete with an excellent concrete

]

control rating per ACI214.

c) The empirically for nulated correction factor for converting 2x2 inch bottom remnant cube strength to corresponding 6x12 inch cylinder strength is .85 for cylinders tested at 90 days and cubes broken at 110 days.

This confirms that the H THIS DOCUMENT CONTAINS 8 0 0 62 00 l 4f l.,

POOR QUAUTY PAGES 201 N. Market - Wichita, Kansas - Mall Address: P. O. Box 208 / Wichita, Kansas 67201 - Telephone: Area Code (316) 264-1111

9 O Mr. Karl V. Seyfrit -

2- October 26, 1979

.8 factor used in previous analyses was appropriate >

for the concrete in question.

Kansas Gas and Electric Company feels that the latest PCA results further support our contention that the basemat concrete is uniform and of high quality with an actual in-situ strength which exceeds 5000 psi.* Also, since the investigation duplicated the mix design, materials and batching aspects of the basemat pour, we again submit that the erroneous low concrete strength results were attributable to inaccuracies in measuring the true strength.

Sincerely yours, fig!4 Nh' GLK:bb Attach l

i l

.,.9 y >-,y

. y _. -