he t@pms for 739 ang yp?39 were derived as in Eqe 3.9.
The ratio
of U activity to U“39 activity, 0.0007, was determined in this
case by a solution of simultaneous equations using actual decay curves
because capture to fission ratios were una
However, because of its short half-life,
ble for this shot.
cannot be calculated
similarly, The fission activity component wast
Ape Aypthe3
(3.15)
where the exponent was determined from decay data after 2000 hr.
A few decay determinations from early~interval samples of
Easy, Fox, and George show that a highpercentage of activity originated prior to Shot 3, probably from Shot le The decay from these
samples follows the relationship:
A=A,(t 4 998)"
(3.16)
where 998 hr is the time elapsed between Shots 1 and 3 and n is the
Shot 1 decay exponent during this periode
The activity values from the first two 30min intervals and
the first 5-min interval were extrapolated to sampling time ny Eq.
3216. All other activities were extrapolated using Eq. 3-14 and 3e15¢
Shot 3 decay exponents are listed in Table 3.4.
decay curve is shown in Fig. 3.2.
3 03 o4
A typical
Shot 4
The activities of Shot 4 samples were corrected to sampling
time by the relations
Asx Ayt-1 04
(3 el? )
where 1.4 is the average of the Shot 4 decay exponents.
The decay curves for this shot are more nearly straight lines
on log-log paper than the curves from Shots 1 and 3, indicating that
the neutron capture activities in samples from Shot 4 are small or
absent; therefore, no corrections were made for these neutron capture
activities. Shot 4 decay values are shown in Table 3.4 and a typical
curve is illustrated in Fige 3045
3305
Shot
Shot 6 activities were corrected to sampling time by the re~
lationships
Az Atte?
(3.18)
The curves show little or no neutron capture activity and no
correction was made for neutron capture activities. The value of -1.2
is the average of Shot 6 decays. Values of individual samples are
shown in Tables 3.4 and a representative decay curve is illustrated in
Fige 34.
44