ORNL-1816 - the Molten Salt Energy Technologies Web Site

ANP QUARTERLY PROGRESS REPORT
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10-4 1cr5 g
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0 10 20 30 40 50 60 70
DISTANCE FROM SHIELD SURFACE (crn)
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Fig. 15.3. Fast-Neutron Dose Rate Measure-
ments in Water Near GE-ANP R-1 Mockup.
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10-1 2-01-056-3-T3A
5
5
2
(0-6
0 10 20 30 40 50 60 70
DISTANCE FROM SHIELD SURFACE (cm)
Fig. 15.4. Gamma-Ray Dose Rate Measurements
in Water Near GE-ANP R-1 Mockup.
mockup emits neutrons in a direction more favorable
for ground scattering. The intensity from the G-E
shield peaks at about 55 and 120 deg from the
reactor-detector center line and is symmetrical
about the reactor-detector axis.
Measurements were also made of the thermal-
neutron flux and the gamma-ray dose rates within
the detector tank at an altitude of 195 ft. The
G-E reactor shield was a horizontal distance of
64 ft from the detector tank, and, for these meas-
urements, five 1-in.-thick lead slabs were installed
1 ft from the rear face (reactor side) of the tank.
The lead slabs simulated the shielding in the crew
compartment.
A knowledge of the thermal-neutron flux di stri-
bution in the detector tank is useful in extending
the fast-neutron dose rate measurements into
regions where the intensity is too low to be meas-
ured with the dosimeter. This distribution is also
necessary for predicting the capture gamma-ray
intensity to be expected in the crew shield. The
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