239, 05,
36 days, from July 7 to August 12, 1972,
table results reported for 236,
The collected 239, 240 Pu activity was
concentrations ranged from 3.5 X 10
distributed lognormally with particle
to 6.3 x 19°13 uCi/em?, with arithmetic
size with an activity median aerodynamic
and geometric means of 6,6 X 19° 15 and
7.9x 107 18
diameter (AMAD) of 3.0 um and a geometric standard deviation of 8.2,
The
uCi/ cm, respectively,
Re-
sults for four soil samples taken from
239, 2405, concentration varied from
approximately the same location range
1.010714 to 3.9x 10 !4 uci/em3,
from 128 to 202 dpm/g, with a mean of
with an average of 2,3 X 19° !4 uCi/com?
for the five samplers,
-17
160 dpm/g!,
At the present
Because the arithmetic
mean is a better representation of average
time only limited data are available re-
lung exposure, it is used to derive a re-
garding the soil activity in the area, ~
suspension factor at this site:
Four soil samples of depth 0-3 cm from
66x10 uci,
em?
approximately the same location have
¢
160 dpm
,_cm®
“1,8 g
x O29 4 107 om ,, 2.22 x 10° dpm |
.been analyzed with results !? of 2060 to
3 cm
3550 dpm/g, with a mean of 2700 dpm/g.
m
pCi
Profile data from other locations at the
-2xX10°/m.
same general site indicate that about 90%
This value is nearly an order of magni-
of the total deposition is contained within
tude higher than the one previously calcu-
the top 2,5 cm of the soil”,
lated, and reflects some of the inherent
Measure-
ments of soil density in the area average
difficulties in the resuspension-factor
1.8 g/cm? ,
approach, i.e., that no allowance is made
is therefore
2.3X 10°
cm?
0.9
x
3 cm
x
The resuspension factor
14
:
uCi x
10% cm.
m
x
.
fz
2700 dpm
cm
for the geometrical configuration of the
3
source and that higher ground activities
“1,8 g
may be present upwind,
2,22 X - 10° dom
It is obvious that this approach is sub-
uci
=-3x1019m,
ject to major uncertainties, but does
Additional air samples were taken by
of the resuspended air activities that may
serve as an order-of-magnitude indication
g
the Reynolds Electrical and Engineering
arise froma 239, 2405), contaminated
Co. (REECo) on the edge of the contamin-
area which has weathered for 15 to 20 yr.
ated area during the pericd of February
The data discussed above also demonstrate
1S71 to July 1972, with a sampling time
unequivocally that resuspension of
of approximately 48 hr
239, 2205. does in fact occur from such
Measurements
were made at four locations, but the
4
aged deposits and at ievels many orders
most pertinent is the one which was most
of magnitude higher than would be ex-
frequently in the direction of strong winds
pected if the often ncted decrease with
from the strongly contaminated area and
time were represented by a single exponen-
where the highest air activities were
tial function with a half-time of 35 to 70
recorded,
days,
Here, 254 individual air-
filter samples were collected and detec-
H-18