NSs-219 and 221 are also currently under study by the NAEG. Some preliminary information on these sites was given by Gilbert et al. (1977b). Phase 1 sampling was conducted at these sites during 1977. Dave Brady of REECo is the principal investigator at Ns's-219and 221. Phase 1 results are discussed by Brady et aZ. (1978) and Essington (1978). VARIABILITY WITH ALIQUOT SIZE STUDY AT NUCLEAR SITE-201 A special study at NS-201 was also conducted during 1977 to help evaluate the relationship between Am (Ge(Li)) concentrations in soil aliquots of different sizes (1, 10, 25, 50, and 100 grams). Twenty-four adjacent surface soil samples (5-inch diameter, 5-cm deep) were pooled together and mixed. All aliquots were withdrawn from the combined sample. The 24 samples were collected 150 feet from ground zero along a line transect (see Figure 9 in Gilbert et al., 1977b, for the location of the transect). The Am activity at that location was about 1.9 nCi/g. Details concerning the statistical design and analyses of this study are given by Doctor and Gilbert (1978). This study was motivated in part by Wallace and Romney (1977a), who discuss the large variability expected in soil samples that have Pu concentrations ac the low levels suggested for cleanup. In general, these data indicate a linear relationship between aliquot variability (standard deviation) and aliquot size (both in logarithmic scale) over the range of aliquot sizes studied (standard deviation decreasing with aliquot size). A number of questions are raised by these results. Does this relationship also hold for Pu variability? Will this relationship be different in areas of higher or lower concentration? Will similar results prevail at safety-shot sites where larger particles of Pu may be present? We recommend that future studies be conducted at nuclear sites and safety~shot sites to evaluate these and other questions. BLOW-SAND MOUND STUDIES Initial Efforts The original soil sampling for estimating surface (0-5 cm) inventory at safety-shot sites was not designed to study the amount or distribution of Pu within blow-sand mounds separately from desert pavement areas. It is true, however, that mounds were sampled, since soil sample locations were chosen at random within strata. 467 However, the number sampled was