ORNL-1816 - the Molten Salt Energy Technologies Web Site

A measurement of the removal cross section of
lithium was made at the Lid Tank Shielding Fa-
cility (LTSF), and the experimentation on the
GE-ANP helical air ducts was continued. Prepa-
rations for the circulating-fuel ref lector-moderated
reactor and shield mockup tests are nearing com-
pletion.
EFFECTIVE NEUTRON REMOVAL CROSS
SECTION OF LITHIUM
G. T. Chapman
J. M. Miller C. L. Storrs’
An effective neutron removal cross section (aR)
of 1.01 k 0.04 barns was determined for lithium at
the LTSF. This value was obtained from measure-
ments made in a medium of oil behind a slab of
metallic lithium which was placed against the
slab of lithium (p = 0.53 g/cm3) was con-
ed by filling a 122-cm-dia by 29.1-cm stain-
nk with melted lithium and allowing
the material to solidify. The walls of the tank
were reinforced with a framework constructed of
‘General Electric Company.
13. LID TANK SHIELDING FACILITY
G. T. Chapman
J. M. Miller
Physics Division
J. €3. Dee
W.
H. C. Woodsum
H. McCool
Pratt & Whitney Aircraft
PERIOD ENDING DECEMBER 70,1954
lnconel window in the wall adjacent to the source.
The presence of the lnconel resulted in CI 9-Mev
capture gamma rayI2 and the photoneutron contri-
bution from this high-energy gamma and the
naturally occurring deuterium in the oil markedly
affected the thermal-neutron measurements in oi I
(no lithium present) for distances greater than
120 em from the source (Fig. 13.2). A 3.81-cm-
thick bismuth slab placed in the oil approximately
45 cm from the source suppressed this gamma ray
and the resulting photoneutrons without my ob-
servable effect on any other component of the
thermal-neutron flux.
The lithium tank was then placed in the oil tank
adjacent to the source, and thermal-neutron flux
2J. B. Dee, D. K. Trubey, and W. Steyert, ANP QUQT.
Prog. Rep. Sept. 10, 1954, ORNL-1771, p 164.
ment.
,APPROXIMATE LEVEL
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