11 distribution data, whichwas taken from fallout samples. this we performed a calculation which ; On takes into account the degradation of the energy due to scattering in the air, due to the distribution of such fallout on an infinite plane. The next question was the rate of decay of the fallout mixture. Here again there is a certain amount of experimental data which seems to indicate that two exponents should be used over the period of time in which we are Washington, D. C Alderson Reporting Company interested, namely, a .8 or .9 exponent during the first Hur 10 hours to four days, and from four days until 25 days, roughly 11 an exponent 12 the Neptunean and fission product combination. 14 evacuation were computed, using these factors, and the time 15 of arrival of the fallout, and the duration of the fallout 16 with the remaining questions considered, 17 very little accurate data, except in the case of Rongerik for 18 the time of fallout, the best estimates possible were made, 19 and doses were calculated on the basis of either a very short 20 fallout or the longest possible fallout that could be assumed 21 to have taken place consistent with the time of commencement 22 and the dose rates which were read at later times by the 23 survey instruments. 24 a Since there is Based on these considerations, we have several sets 25 Ty Historias’: 7 -.. _ The best estimates of the dose rate at the time of 13 ARC Dapartment nf Te of about 1.6 seemed to fit the combination of of doses which are in substantial agreement with Mr. Sharp ‘ ehh tw 7. NABRCH ; I