Very few measurements have been made of 7“'am movement in soils.
Dif-
ferential movement of americium and plutonium appears to have occurred
in some of the soil profiles collected by NAEG. Essington (1976) pre-
sented a profile of
239, 240py 724 Ian which indicated that small amounts
of *“!1;m appeared to be moving faster than 739-2" py at the Safety Shot
sites.
It should be pointed out, however, that not all of the prcfiles
taken showed this pattern; **1am and 739*2%%p5y appeared to move at the
same rates
in many of the profiles.
FRACTION OF TOTAL PLUTONIUM
Accidental Releases of Plutonium
0.01
0.00!
0 f
from this experiment
Plutonium predicted
from the analytical
results might be influenced
by the cross-contaminating effect of the coring tool.
Smail particles
of plutonium or plutonium oxide may have been dragged from the more
radioactive surface soil into deeper profile samples, giving the appearance of a constant level of plutonium with depth.
The other major accidental release of plutonium for which soil profiles
were investigated occurred at the Rocky Flats, CO, Nuclear Fuels ReProcessing Plant. A series of fires occurred over the years possibly
releasing small amounts of plutonium to the environment, but probably
the largest concentrated release occurred when drums filled with
plutonium-laden oil and cuttings began leaking,
To determine the distribution and amount of ??%py around the environs of the Rocky Flats
plant, Krey and Hardy (1970) began a sampling program which included
evaluation of the vertical distribution of 7)%pu (239724 OBy) in the
local soils.
A number of soil profiles were taken in 1970,
J
oO
In review-
it was noted that the distribution of
~
aA coring method was used to col-
lect the soil profile samples from the two Palomares plots.
ing the data
ol
oO
tonium profile from the plowed field.
SOIL DEPTH (cm)
a series of plots were located for the purpose of following the digs-
persion of the remaining low levels of plutonium from virgin land and
from cultivated land. Figure 8 shows two such plutonium profiles which
are the result of averaging nine fractional cores from each site. The
effects oF eens the soil can be seen in the highly variable plu-
{
°
“Tt
Fowler et al. (1968) reported results of soil sampling for Plutonium at
Palomares, Spain, after the accidental destruction of two nuclear |
weapons in that farming community.
After considerable cleanup effort,
al
40
Fig.
VIRGIN
PLOWED
—
ellLLL.
&.
Let ii ii.
ib Ee tts
Distribution of Plutonium in Palomares Soil
(Adapted from Fowler et al.,
two of
which are shown in Fig. 9. Plutonium-239 was found to a depth of
13 cm although the distributon was widely variable, presumably due to
differences in soil chemical properties.
In some cases as much as
60% of the 77°Pu was below 5 cm.
58
59
1968}.