+ tate meet EXPOSURE RATES CALCULATED FROM SOIL SAMPLE DATA 137 as G2 AG ~25 oh Clearing Experiment Area Total activity per cm’® 4200 pe 90 pe 600 pe Calculated from concentra- 240 ur/hr 19 ur/hr 24 uwr/hr tion in soil sample Inferred from field spectrum 52 ur/hr 6 wr/hr 9 ur/hr 84% 8% 6% 77% 9% 14% Percentage of total exposure rate based on soil analysis (see p. 11) Percentage of total exposure rate from field spectrometer and ionization chamber data 10 (pc/gm) feet north of center 30 feet north of center 74 251 ww A i or Core activity 74 26 The percentages of the total exposure rate due to each isotope were calculated as discussed in Section II ({p. 11) and agree reasonably well with the field spectrometric data in contrast to the calculated exposure rates which are quite high, mich higher than could be explained by the excess activity from 3 - 5 inches. The core data also given in the table illustrate the large local variation in the total activity which is probably the main reason for the high values for the calculated exposure rates. This cleared area was resurveyed two weeks later upon return to Bikini Island. The exposure rate measured at the center of the area was essentially the same as before ur/hr). (59.6 Additional measurements were made around the edges