CLEARING EXPERIMENT EXPOSURE RATES

(ux/hr)

Radius of

Cleared Area
0!
10'
20'
30!

13745

B° a9

47.2
48.6
50.8
52.2

5.2
5.2
5.5
5.7

125 op

Total

9.1
8.6
8.0
8.5

61.5
62.4
64,3
66,4

As
59.0
59.0
59 9
60.5

The slight increase in the total of the *°’Cs, °°co, and
+25 sh 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
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
Area

Scaevola
Pounds

ra $2

IN CLEARING EXPERIMENT
Dodonea

Litter

of Aerial Portions

10 £t. radius
10 - 20 £t. radius

593
1717

33
112

59
364

20 —-

2902

67

386

5212

212

809

30

£t.

radius
Total

4

Select target paragraph3