CLEARING EXPERIMENT EXPOSURE RATES

=tern

(ux/hr)

:s
Llation

Radius of

Cleared Area
insects

-

of the
Along
on

ore

:ruction
mM areas;
side

‘ high
leter
i@

area.

ntion
‘faces.
btained

aring
active
xternal

ptake

O'
10'
20'
30'

osure
nmarized

47.2
48.6
50.8
52.2

5.2
5.2
5.5
5.7

+#5 sb

Total

As

9.1
8.6
8.0
8.5

61.5 |
62.4
64.3
66,4

59.0
59.0
59.9
60.5

reduction in the scattered radiation and thus little effect

on the total exposure rate.
The more important effect of
the vegetation seems to be to enhance scattering of the
radiation from emitters in the soil thereby producing a
slightly softer energy spectrum.
This effect more than conpensates for the increase in exposure rate at the detector
due to radiation originating in the vegetation itself.
The quantity of vegetation removed was staggering.
As
the brush was removed from the area, it was identified and

weighed.

These statistics are given below.

VEGETATION REMOVED IN CLEARING EXPERIMENT|
Arga

Scaevola
Pounds

rometer
es-

5° Co

The slight increase in the total of the *°’Cs, S°co, and.
+“5sb exposure rates indicates that there is possibly some
increase in the unscattered gamma radiation affecting our
partial exposure rate estimates, but there is a corresponding

the
ola
oO ft.
dings

ny

*27Cs

10 ft.

of Aerial

radius

10 - 20 ft.
20 - 30 £t.

radius
radius
Total

Dodonea

Litter

Portions

593

33

59

1717
2902

112
67

364
386

5212

212

809

- 25 f°

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