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in polyethylene containers.
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Concentrations are based on the
Weight of the material at the time it was received at HASL.
Con-
sequently, all radiochemical and analytical results are reported
here in terms of d/m or grams, per gram of material as received
at HASL. Dr. H. Weiss has stated via letter?) that the wet
weights of the plant specimens were not recorded at the time of
collection.
He has proposed that the results be expressed in
terms of d/m/kg of material as received at NREDL.
For determination of totalbeta activity an aliquot of
‘the solution of wet-ashed material was transferred to a glass plan-
chet, evaporated and dried under an infra-red lam.
Counts were
converted to disintegrations by applying a geometry factor based
on x40 as a standard.
<Aself-absorption correction was also ap-
plied in each case.” Under the wet ashing and plating conditions
used at HASL possible loss of volatile fission products such as
Ryt06 ~ Rhl06 is avoided. (3)
For practical reasons, the coconut
outer and inner shells were dry ashed at 500°C prior to dissolution.
# For the particular specimen type under consideration, several
values of activity vs. dry weight of the plated aliquot were
plotted and a smooth curve fitted for the
points.
Another
curve (based on extrapolation to zero nase) of activity ratio
(A/Ao) was drawn and used for determining the self-absorption
correction. See Figures 2 through 8.
~—§0020b9