

Available from: NC State University Archives



20 October, 2000

Nuclear Reactor Digitization Project

R. L. Murray Reactor Project Notebook

Illustrations have been included from the print version. Scanned by Russell Koonts with Photoshop 5.0 software. Memorandum from R. L. Murray to Dr. Clifford K. Beck A. C. Menius, Jr. R. L. Murray

2 pp. Manuscript copy consulted UA 105.16




Library of Congress Subject Headings
1951 English LCSH manuscript 24-bit color: 400 dpi
Memorandum from R. L. Murray to Dr. Clifford K. Beck Typescript 2 pp. 1951 MurNBingredients000051

SHIELDING77947294 TO: Dr. Clifford K. Beck FROM: R. L. Murray CC: A. C. Menius, Newton Underwood

This note answers your request for calculations on the heavy concrete.

The composition of Barytes mix, according to the Carbide purchasing agent is, per yd3, Barytes3970 lb72.0 Colemanite400 lb7.3 Portland cement830 lb15.1 Water310 lb (37.5 gallons)5.6 Total mix5510 lb100.0

Since the Colemanite consists of B2O344% CaO27% H2O28%

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/tonEstimated shipping cost $4/tonColemanite $60/tonEstimated shipping cost $15/ton

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 Cement, 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 shield is 107 yd3, so that the cost would be ($70)(107)= $7500. Of this, the critical item so far as shipping (from California) is the 21.4 tons of Colemanite. However, it only constitutes 7.2% of the mix, and 20% of the cost, so it would probably be worth the invest- ment to achieve the full degree of shielding, rather than using an inner lining 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.

Letter of Feb. 23, 1951 - R. N. Reams to C. K. Beck

Based on Mr. Stainback's figures on W. Va. coal shipping

Freight agent, Seaboard Railway

Barytes:Ba 41.9% O 31 S 9.9 Fe 8.7 Co 4.5 Si 1.7 other 3.3 100

Quoted by N. C. State Products Corp.

Assume top slab = hole inside
V= 17x17x10 = 2890 ft3=107 yd3