at three of them. A number of transects of the island and routes around the island were made to obtain measurements with the portable counters. The approximate locations of these measurements are shown in Figure 7. The portable survey instruments indicated exposure rates from 10 to 60 ur/hr around the edge of the island and from 15 to 160 ur/hr near the center {see Table 1). Isolated areas had much higher radiation levels, particularly the northeastern section where exposure rates of over 200 ur/hr were measured. The spectrometer measurements indicated that the major contributor to the radiation field was °°Cco. This was the contamination on the buried metal scrap, but the radioisotope was also found in a soil sample taker from the island. The other major contributor was ~*’Cs. were present. Only small amounts of **°Sb The exposure rates due to each isotope and its percentage of the total is shown below for each location, along with the total exposure rates measured with the ionization chamber. SPECTROMETER AND IONIZATION CHAMBER EXPOSURE RATES (ur/hr} Location 1 (Center near bunker) 2 (Northeast ey) corner) 4 (Near lagoon shore) (Center on western side) *87 as E © a0 8" oH Total Aa 25.8(39%) 39.4 (59%) 1.1 (2%) 66. 3 75.5 60.6(33%) 119.5(66%) 2.0(1%) 182.1 204.0 18.1 (50%) 17.2 (48%) - 6 (2%) 35.9 34.1 55.3