ORNL-4191 - the Molten Salt Energy Technologies Web Site

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5
2
4 o~~
40"
5
2
5
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I t 1
ORNL DWG 67-12234
0 10 20 30 40 50
DISTANCE FROM SURFLCE (mils)
Fig. 9.1. Distribution Profile of 99M0 in Graphite
from MSRE Core.
meaningless. Figure 9.4 indicates that there
probably was measurable penetration of 'Zr to
a depth of 50 mils.
Figure 9.5 shows that '32Te concentrates, as
do the noble metals, at the surface; however. a
measurable concentration of this element penetrates
to a depth of 50 mils. The behavior of
fission products with rare-gas precursors is
shown in Figs. 9.6 (I4'Ba) and 9.7 (sgSr).
Because of the concentration at the surface,
the amourits present in the several layers near
the surface were representative of the total
122
Id'
5
2
5
2
lo9
5
2
108
: - - - I I
~ .
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1
, I
. . . . . . . . . . -. . -
ORNL---DWG 67-12232
0 10 20 30 40 50
DISTANCE FROM SURFACE (mils)
Fig. 9.2. Distribution Profile of 95Nb in Grophite
from MSRE Core.
amount of many isotopes in the graphite. Table
9.3 shows the quantity of several materials (in
disintegrations per minute per square centimeter)
on graphite specimens as functions of position
and of exposed face. In each case, face No. 3
was in contact with other graphite and was not
exposed to salt. In general, this face contained
about as much activity as those exposed to salt;
this finding supports the view that the deposited
activities were gas borne.
In lable 9.4 the values (averaged for all faces
of the graphites) obtained in the specimens ex-
posed for 24,000 Mwhr are compared with the