4-5
GAS ANALYSES
Although detectable quantities of gaseous radioactive isotopes of
interest were measured in approximately all close-in gas samples, the
results were disappointing, since there was extreme variation and inconsistencies in the proportionate concentrations of these isotopes throughout
the samples obtained. Analysis of long-range gas samples were equally
disappointing. In addition to the inconsistencies observed close-in,
long-range samples were further complicated by lower concentrations of
debris radioactive gases in the presence of significant background levels,
particularly with respect to Kr®, which was to be used as a fission refer-
ence.
The variability of radioactive gas atom ratios for the close-in
samples is probably due to unrepresentative samples of the cloud, as all
samples were taken at altitudes well below the altitude attained by the
main cloud. There is no guarantee that this variability would be eliminated by sampling at 75,000 to 80,000 feet for the megaton shots, however,
as there are still insufficient data with respect to fractionation of the
debris gases either with respect to each other or with respect to the
particulate portion of the cloud.
The environment of the explosion-~-
water or barge shots at Eniwetok and Bikini---carry such large quantities
of water into the atmosphere that serious effects in attempting to get
representative and quantitative tritium measurements under these conditions
would be expected, particularly during the first twelve hours after detonation when rainout and/or fallout is very prevalent. This factor appears
significant, as the extreme variations in H*/Kr® ratios are normally not
observed in sampling shots at the Nevada Test Site---e.g., as observed
during Upshot-Knothole. This comparison is not absolute, since mgaton
shots have never been fired at Nevada. However, during Operation Teapot,
analysis of about ten shots gave gas atom ratios that were quite reason~
able within theoretical expectations. From this latter fact, it was
_
concluded that the sempling equipment and laboratory analysis for the
vari~
unreasonable
the
of
sources
close-in samples were not the principal
ations observed in the gas data. The long~range samples may be compromised
within the sampling equipment itself, since it is known that recovery of
tritium from the sample containers, quantitatively, is open to serious
question.
Hence, the overall comparison of close-in analyses with long~
range analyses is not considered completely valid, because of the differ-
ences in the sampling equipment used.
It is anticipated that for Operation
Redwing, sampling equipment will be completely converted to Squeegee type-~
both close-in and at long-range.
thatl
viewing the data on an overall and qualitative basis, it appears
ratios for the Castle shots are significantly higher than those
observed for Ivy~Mike.
The range of values for Ivy~Mike is
all Castle shots indicate ratios greater}
“Majority of the samples analyzed.
ratio
_ Jin the
Theoretically, based on reactions in
39