This note answers your request for calculations on the heavy concrete.
The composition of Barytes mix, according to the Carbide purchasing agenta is,
|Portland cement||830 lb||15.1|
|Water||310 lb (37.5 gallons)||5.6|
|Total mix||5510 lb||100.0|
Since the Colemanite consists of
The boron content at the final mix is almost exactly 1%, as computed below:
The density of the concrete is
or its specific gravity is
The ORNL figures for this concrete are 1% Boron, 3.5 specific gravity. The
neutron flux data show that in a 6 foot shield, the attenuation with the 1% B
concrete is 100 times that for Barytes without B.
The minimum cost figures quoted by CCC&D are
|Barytes aggregate $20/ton||Estimated shipping cost $4/tonb|
|Colemanite $60/ton||Estimated shipping cost $15/tonc|
The fractions of each in the mix are Barytes 3970/5510 = 0.72, Colemanite 400/5510 = 0.072.
Assuming a figure of $16 a ton for Portland Cementd, with 830/5510 = 0.15 required,
the cost is
[(0.72)(24) + 0.072(75) + (0.15)(18)] 5510/2000 = $70/yd³
A good estimate for the volume of concrete in the shielde is 107 yd³, so that the
cost would be ($70)(107)= $7500. Of this, the critical item so far as shipping
7.2% of the mix, and 20% of the cost, so it would probably be worth the
of the Boron cement. Special forms might be needed also, which would run up
the construction cost. The cost estimates for a 4 ft inside lining corresponding
to 1440 ft³ = 53 yd³ are computed for consideration, anyway. This is half the
reactor volume. Substituting Barytes for Colemanite would reduce the yd³ cost to
only $65 and the total concrete to $7000.