In June and July of 1979, soil was selectively removed with earth-moving equipment from the
loeations in the Fig-Quince area with highest TRU activity based on original data. (See Tech Note
23 for discussion of original versus final data.) After each soil lift, the locations involved were
remeasured with the IMP, and moresoil lifted, again from the locations with highest TRU activity.
In the Fig-Quince cleanup, a total of approximately 8,200 cubic meters (10,735 eubie yards) of soil,
containing an estimated 7.2 curies of TRU activity, was removed.
After the soil excisions, a layer of soil with relatively low TRU activity was spread over the

locations in the Fig-Quinee area which still had TRU activity, based on original data, in excess of

160 pCi/g (see Section 6.10).

Fission Products Sampling and Final Characterization
Beeause the numerous structures and soil confinement operations made sampling very difficult on

northern Yvonne, only southern Yvonne was sampled in the Fission Product Data Base Program.
Samples were taken at 14 locations, and soil from 5 of these was analyzed for 99Sr, Tables 7-1, 7-2
and 7-3 summarize the results for 0-15 em data for 137s, 90sr and 39,240 py, respectively. Island
averages for other depth ranges are given below for 137Cs and 94sp,
90

Sr, pCi/g

1876.pci/g

0-5 em
1.3

1.6

0-40 em
1.1

1.4

0-60 em
1.2

1.5

Total
Samples
27

81

Following completion of the cleanup, soil confinement operations and dismantling of structures on
Yvonne, the entire island was measured with the IMP at 25 m spacing. Figures 7-108 and 7-109 show

the sampling locations, and Figures 7-110 and 7-111 show isopleths_on the final post-cleanup surface
TRU on Yvonne. Table 7-5 summarizes island average data for 137¢s, 60Co and TRU activi ty from

IMP readings.

The overall TRU average for southern Yvonneis 7.8 pCi/gm and for northern Yvonne is 41 pCi/gm.
Although the surface of Yvonne is technically within the numerical standard for the Food Gathering
classification, the complex and unique radiological condition of the northern portion of the island
leads to the conclusion that Yvonne should not be so classified. The island is currently quarantined.

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