we N w6 w4 we Bt E2 E4@ LAGOON APPROXIMATE HIGH TIDE LINE, i972 A = US. NAVY MONUMENT © = IMP LOCATION = SOIL SAMPLE LOCATION LUCY — KIDRINEN 50 m FIGURE 7-27, COASTLINE AND DATA COLLECTION LOCATIONS FOR ISLAND LUCY 1972 Survey Twenty-eight locations were sampled during the 1972 survey and a few vegetation and animal samples were also collected. Of the 28 locations, 23 were 0-15 em core samples, two were 0-35 em profile samples, two were 0-65 cm profiles, and one was a 0-115 em profile sample. The profile samples indicate a steep decrease in activity with increasing depth to a depth of 10 Sy then a more gradual decrease or leveling off in activity below this depth. Generally, the 239,240 py activity shows a sharper decrease than the 137cs and 95sr activities. The 239:240py soil profile results did not indicate that elevated subsurface TRU activity would be expected. Tables 7-1, 7-2 and 7-3 give summary statistics for the 137s, 90sp and 239,24 Pu, respectively, for the 0-15 ¢m core samples. Characterization Lucy was staked on a 50 m grid and IMP measurementsfirst taken in February 1978. To determine a TRU to 24lam ratio, soil samples were collected at five locations with two composites at each of three depths for a total of 30 samples. (See Section 4.2.1 for more information on surface soil sampling.) A ratio of 2.59 + 0.03 was calculated based on these soil sample results (see Tech Note 2.6). Figure 7-27 shows the locations of the IMP measurements and the soil sampling. Before any estimates of 0.25 hectare averages were made, comparisons between the IMP 241 am data and the soil sample results collected at the same five locations indicated a significant difference. This difference had not been observed on any of the data collected from otherislands. 235