13
The calculations agree with the rather imprecise measurements for
all the data from tower shots except for shots Ray and Met.
The
measurements on fallout from balloon shots are lower than the
calculated figures by a factor of about five to eight.
There is no
single nuclide of the peak fission products or major activation product
that can produce such a result.
Therefore, I conclude that the
counting samples used to measure uCi/me from all balloon shots
contained only about 20% of the amount of radionuclides that should
have been present, and, consequent ly, the samples are not
representative of the surface deposit.
FRACTIONATION OF TOWER SHOT DEBRIS
Fallout collected from four tower shots in 1957 was sorted into
particle size fractions by wet sieving (La66).
Before radiochemical
analysis, the heta disintegration rate for each fraction was determined
for 8920.5, 9ly 7, 103,106p,, 136¢, 140, and
141,144 04,
The results for each size fraction were reported as
percentage of the total beta activity in that size cut due to each
nuclide, but the fraction of the total beta activity of each size cut
_was not reported in La66.
Therefore, these published data could not be
used for comparison with calculations of the radionuclide composition
of undisturbed fallout.
The original data sheets were recently made
available by the Nevada Operations Office of the Department of Energy.
I synthesized the radionuclide composition measured for each
undisturbed fallout sample from the information in these data sheets