intensive study sites.
To date, there are approximately 100 profiles
from Area 13, Area 5-GMX, Area 11, and TTR (Fig.
3).
More profile
data will be available when analyses are completed.
In scanning through all the profiles, one is able to categorize each
profile into one of three classes:
(1) "high normal," where > 95%
of the radionuclide content is localized in the top 5 em;
(2) "low
normal," where there is insufficient radionuclide content to show
profile development; and (3) "abnormal," where there occurs radionuclide profile development at some depth other than, or in addition
to, the top 5 cm.
Fig. 4 shows what is considered a "typical" or
“high normal" profile.
That profile was taken from Area 13 in the
outermost stratum, furthest from GZ.
of the Pu is in the top 5 cm.
As the graph shows, the majority
What appears to be profile development
below 5 cm is open to question.
The level of Pu found in each incre-
ment may be the result of Pu migration but is so low as to be questioned on at least three fronts:
sampling,
(2)
(1) cross-contamination during
cross-contamination during sample preparation,
statistical variation in laboratory analyses.
and (3)
The procedures for
sampling and sample preparation were designed to minimize crosscontamination,
but the statistical variation in laboratory analysis
may account for the observed results.
It is believed that any Pu
analysis resulting in radioactivities below 0.1 d/m/g from a 10-g
sample should not be directly compared to a sample of similar radioactivity.
Only after consideration of the variability generated in
obtaining the analysis should comparison be made.
Order-of-magnitude
difference could occasionally be found, particularly if hot particles
of Pu are present.
Closer observation of Fig. 4, however, does suggest that some Pu has
moved to the region 5-20 em by some mechanism such as:
change,
(1) ion ex-
(2) complex migration, or (3) particle migration.
The profiles, then, range from the "typical" (Fig. 4) to the "abnormal"
(Fig.
5); a profile taken from Clean Slate 1, again in the stratum
furthest from GZ.
Here, in addition to a substantial portion of Pu
at the surface, there appears to be two additional bands of Pu--one
at 10 cm and one below 17.5 cm.
There is evidence that much of the
24
ane