new Pu results from the stored library samples.* It is clear that Pu concentrations on the periphery of the 200-foot grid (to the south, east, and west) are in the picocurie per gram range. A series of five soil samples were also collected along an east-west line 4,000 feet north of the ground zero at NS-201. Table 1 gives the 137¢5, Am, and estimated (see footnote in Table 1) Pu results for these samples. The data in Figure 4 and Table 1 suggest additional samples may be required further north along the fallout pattern if the extent of this pattern needs to be accurately known. New Studies at Nuclear Sites-200, 201, and 202 Preliminary results available in the fall of 1976 at NS-201 resulted in the design of a more intensive soil sampling program at this site (dis- cussed briefly by Gilbert et al., 1977b). This new effort resulted in the collection of 320 additional soil samples at the grid points indicat- ed in Figure 5. It is our understanding that these soil samples have not been shipped to analytical laboratories for Pu and other radionuclide analyses. If these analyses are completed in the future, the data could be used to estimate Pu spatial distribution and inventory using kriging and/or more conventional techniques. The preliminary grid data may also be useful in this effort. These early samples were selected to avoid rocky areas. Whether this tends to bias their concentrations relative to the later results collected on the grid in Figure 5 will need to be evaluated. The new sampling effort at NS-201 also included additional samples of vegetation, metal fragments, and soil profiles (for both inventory and particle-size analysis purposes). In addition, samples from the large debris mound at ground zero were collected and quality assurance soil samples prepared. time. Results from these samples are not available at this During 1977, we also began design work at NS-200 for estimating spatial distribution and inventory. By June, 1977, the Phase I grid design depicted in Figure 6 had been finalized and was available for implementa- tion when resources became available. The location of Phase 1 sampling grids at NS's-201 and 202 are also shown in Figure 6 since they are in close proximity to NS-200. Phase 1 sampling plans for these two nuclear sites are given by Essington (1978). It's possible the fallout pattern of NS-200 overlaps that of NS-202. Hence, the narrow band between these two sites may also require sampling at some future date. The data from these three sites may indicate that the entire region should be considered as a single unit rather than three separate studies. *Not included are 5 Pu concentrations for 0-2.5 cm soil samples col- lected at 0, 100, 300, 400, and 500 feet from ground zero along a transect. See Figures 7 and 9 in Gilbert et az. (1977b) for these results. 463