estimated to be 4] pCi/g. An estimated 1375 cubic meters (1800 cubie yards) of soil containing an
estimated 0.16 curies of TRU activity were removed from the Hustead area based on final data.
Other Activities

In February 1978 detector SN:496 was installed on one of the IMPs. This deteetor was mistakenly
operated at a bias voltage of -2000 v rather than -3000 v from 3 February to 25 February 1978, To
correct the IMP data already collected, remeasurements were taken at nine different locations in
the Kickapoo area with the correct bias voltage. Data had already been taken at these locations

with the lower voltage. A comparison was made of these results and a correction factor of 1.16 +
0.25 was determined. (See Tech Note 5 series for more information on this experiment and others

connected with detector SN:496.)

In order to determine total TRU activity removed in the Kickapoo and Yuma areas, a method using

truck samples was attempted. Soil samples were taken from each truck loading from the cleanup
area and analyzed by gamma spectroscopy to determine the 24lam. after reviewing this method
and comparing it to the method which used the IMP results, it appeared that the truck sampling was
not a feasible technique for determining curies of TRU removed. (See Tech Note 10.0.)
Because the PACE area on Sally was swampy and in poor shape for agriculture, a restoration project
was conducted. In order to ascertain that no high TRU concentrations would be exposed during this

operation, subsurface soil samples from potential borrow areas were taken in June and August 1978.

Figure 7-104 indicates locations sampled and also the areas the fill came from. The results from

these samples showed no elevated TRU concentrations in the subsurface but two surface results

showed high activity. These areas were then measured by the IMP and showed TRU concentrations
of 30-35 pCi/g.
Fission Product Sampling

In support of the dose assessment (see Section 6.11), a fission products sampling program was
conducted on Sally during March 1979 on the 50 m grid already established. Out of the 139 locations
sampled, 90g, analysis was done on 39. The following table gives the arithmetic mean for 90sp and

137Cs for certain profile ranges.

90s, pCi/g
137% C6, pCi/g

0-5 em

5.6
4.2

0-40 em

3.0
2.5

0-60 cm

2.9
2.2

Total Samples

232
809

Tables 7-1,, 7-2, and 7-3 give some summary statistics for the 0-15 em depthsforthe 1375, 90sp and

estimated 239,240py results respectively, and Figures 7-105 and 7-106 show isopleths for 0-40 cm
profile mean data over the entire island for

37Cs and

Sr, respectively.

Another major project associated with Sally was the Aomon Crypt mentioned previously. (For
complete details, see Section 6.8.) Because this crypt was along the causeway, most of the soil and
debris was stockpiled on Sally. After the stockpile was hauled away, the area was measured by the
IMP to verify that no elevated TRU activity remained.
Final Characterization

Following recontouring of the PACE area, surface soil samples and IMP measurements were taken in
the areas affected. The soil sample results yielded a TRU to 241 Am ratio of 3.2 with all IMP 24lam
values less than 2.5 pCi/g; therefore, all TRU activity was less than 8.0 pCi/g. Figure 7-107 shows
the isopleths for, the final Sally data and Table 7-5 shows the mean of the IMP results for the

calculated TRU, !37Cs and 6Co for this island.

The island average transuranics value reported in the Certification is 7.5 pCi/gm for surface soil,
and the transuranics classification is Residence.

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