TABLE

2.4

Beta Activity in Soil Samples Taken From Exposed Soil Profiles
Beta Activity (87/min/g)
Depth
(in.)

Rongelap

Labaredj

Island
Ka belle

Ka belle

Ka belle

Otol

12,400

130,000

72,000

93,000

97, 000

3

1,500

380

6,800

2,900

440

6

110

950

1,700

400

130

9

140

710

130

2,300

240

12

NDA ()

160

40

580

140

18

10

120

10

70

90

40

100

70

NDA

24
30
36
40

.

NDA
60

:

40

No detectable activity
~

(a)

;

Table 2.5 summarizes the data derived from the tube coring
Samples. Cores were analyzed in l-in. increments and while some

movement of activity along the walls of the tube was probable the results for the most part agreed rather well with those obtained by the
other sampling procedures.
A comparison of Tables 2.3, 2.4, and 2.5 indicates that the coring technique falls down somewhat at high levels of activity although the
apparent movement of activity may be real and may be afunction of the
soil particle size and not a mechanical cross-~contamination.
The data in Table 2.5 show very definitely that the residual
activity on the islands is contained primarily in the top several inches
of soil and that movement is occurring. Data presented in Chapter 3
deal with the nature of the contamination in the environment and from
them it can be deduced that fractionation takes place, with Ce!#4#_pr/44#
and Ru!%_Rpl% making up much of the fixed contamination. The plant

at

ar™

2 FT

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