STATISTICAL ANALYSIS OF "A SITE" DATA AND INTERLABORATORY COMPARISONS FOR THE NEVADA APPLIED ECOLOGY GROUP R. O. Gilbert and L. L. Eberhardt Battelle Memorial Institute Pacific Northwest Laboratory Richland, Washington ABSTRACT Preliminary estimates of the inventory of 235 U and 238 U in surface (0-5 em) soil of A Site in Area 11 of the Nevada Test Site (NTS) are 1,045 + 274 (+ S.E.) and 10,500 + 1,150 grams, respectively. The inventory of 2354 due to the device alone: i.e., after subtracting off the estimated inventory of natural U » is estimated to be 983 + 274 grams. The like estimate for 238 U is 1,920 + 1,150 grams. 239-240 Pu in surface soil for A Site is The estimated inventory of 0.0347 + 0.012 curies. Average concentrations of 2354, 238) , and 239-2405, are estimated for both soil and vegetation. The ratio of these means (vegetation/soil) for 235 decrease from 0.16 to 0.0039 with decreasing distance from ground zero. The decrease is from 0.028 to 0.0066 for 2385. The concentrations of 2344 and 236y for vegetation are about 100 times less than for 235 U or 238y for vegeta- tion. The data from four profile samples are plotted and show the rapid decline in concentrations of 2354 with depth. This does not 238 U, however, presumably because most 238 U present is occur with natural uranium, Data are presented to compare 239-2405, concentrations in ‘''ball-mill" versus "sieved" (<100 mesh) soil fractions from soil samples analyzed by two laboratories. Most data examined here via simple regression techniques suggest that for soil samples collected in relatively-high- 117