using kriging or other methods. The general protocol for Phase 1 sam- pling is given by Essington (1978). He also gives the Phase 2 protocol developed for NS-201 discussed in the next section. Results at Nuclear Site~201 At the NAEG Pu Information Conference held in March, 1977, we presented the design and analysis work accomplished during 1976 at NS-201 (Gilbert et al., 1977b). This included the analysis of preliminary soil samples at 315 grid locations. These data were used to estimate the spatial patterns of !37’cs and Am over the study site. The ratios of Am to 137¢5 concentrations were quite variable (from less than 1 to over 50) over the study site. Pu to Am ratios did not appear to change with location, the median ratio being 11.2 with 95% confidence limits of 8.3 and 14.1. Some preliminary analyses on metal fragments, profile samples, rocks, and soil fractions were also given. A portion of the preliminary grid results were not available in March 1977. These were 68 grid locations near ground zero chosen to better define spatial pattern in that region. Figure 9 in Gilbert et al., 1977b.) (These locations are shown in Data for these 68 locations are now available and are given here in Figures 1, 2, and 3. These figures show hand-drawn (by REECo personnel) contours of Am, !37cs, and beta + gamma instrument readings, respectively.* Figures 1 and 2 may be used in conjunction with Figures 10 and 11 in Gilbert et al. (1977b) for a more complete picture of concentration patterns at NS-201. The beta + gamma readings were taken to help evaluate how useful they might be in the Study of nuclear sites. It's clear that they do show some patterns of interest near ground zero. However, at further distances the instru- ments are not sufficiently sensitive to be very useful. As mentioned above, Figure 13 in Gilbert et aZ. ratios obtained at various locations at NS~201. (1977b) shows Pu to Am These locations were along the main fallout pattern and were the only samples for which Pu analyses had been done. Hence, there was a lack of Pu information in what were expected to be low concentration areas. As a consequence, aliquots from a number of the stored library soil grid samples collected on the 200-foot grid, but away from the main fallout pattern, were analyzed for Pu. These data became available to us in August, 1977. The Pu concentrations of all presently available Pu results for 0-5 cm surface samples are shown in Figure 4. These include locations where Pu to Am ratios were given by Gilbert et al. (1977b, Figure 13), and the *Sampling locations are at the grid line intersections in Figures 1, 2, 3, 4, 6, and 7. the dots. In Figure 5, the sampling points are at the location of 458