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ANP PROJECT PROGRESS REPORT
TABLE 5.21. SUMMARY OF THE CONFIGURATIONS
USED FOR LTSF MOCKUP TESTS OF ADVANCED
SHIELDING MATERIALS
Configuration
No.
Cornpositlon
69-0 Pure water
Transformer oil
69-1 1 ft of LiH in oil
2 ft of LiH in oil
3 ft of LiH in oil
69-2
69-6
69-7
.
4 in. of Zr in oil
4 In. of Zr + 1 ft of LiH in oil
4 in. of Zr +2 ft of LiH in oil
4 in. of Zr + 3 ft of LiH in oil
3 in. of Pb in oil
3 in. of Pb + 1 ft of LiH in oil
3 in. of Pb +2 ft of LiH in oil
3 in. of Pb +3 ft of LiH in oil
3 in. of U in oil
3 in. of U + 1 ft of LiH in oil
3 in. of U + 2 ft of LiH in oil
3 in. of U +3 ft of LiH in oil
distances from the source is interpreted as an
effect of photoneutron production in CI3 and deute-
rium, although no quantitative analysis has been
made. At smaller distances from the source, these
data may be used to estimate the macroscopic re-
moval cross section of lithium hydride at room
temperature in an oil medium. A preliminary value
of 0.12 cm” was obtained, which is in good agree-
ment with the value expected on the basis of pre-
vious removal-cross-section measurements on a
lithium-metal slab.‘
The observed gamma-ray tissue doses are given
in Figs. 5.2.6 through 5.2.9. It can be noted that
270
TABLE 5.22 PHYSICAL PROPERTIES OF
THE SHIELDING MATERIALS TESTED
Material Description
Transformer oil Density, 0.87 g/cm3 at 20°C;
analysis, 86.7 wt % C and
12.7 wt % H
Lithium hydride* 5 x 5 x 1 ft slabs encased in
AI cans ($-in.-thick walls);
density, about 0.75 9/cm3;
purity, about 95%
Zirconium*
Lead
Uranium
52 X 55 x 2 in. metallic slabs
55 X 60 X 1.5 in. metallic slobs
52 x 55 x 1.5 in. depleted me-
tallic slabs containing 0.24
wt % u235
*Raw rnateriols furnished by GE-ANPD.
one slab of lithium hydride behind a heavy shield-
ing material reduces the dose at larger distances
from the source. This is interpreted as a reduction
of secondary gamma-ray production caused by the
presence of Li6 in the lithium hydride. The data
obtained upon subsequent additions of LiH indi-
cate, as expected, that LiH does not have so large
a macros cop i c gamm a-ray absorption coefficient as
that of the oil.
It is planned to continue these studies of combi-
nations of lithium hydride with other shielding
materials. Attempts will also be made to obtain
reliable fast-neutron measurements, where pos-
sible, for the configurations already studied.
4G. T. Chapman and C. L. Storrs, Effective Neutron
Removal Cross Sections for Shielding, ORNL-1843 (Aug.
31, 1955).
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