-4. Figure 3 shows the estimated exposure rate readings on D+ 1 day based on monitoring data made by personnel on the ground two to four days after the detonation. 2. The usual factor of time -}-2 was used to convert these data to exposure rate readings at D+ 1 day and to the two day out- of-door doses shown in Figure 2, The validity of using this conversion factor may be estimated by noting the exposure rate readings taken on the Island of Rongelap (Figure 4).2° There was essentially no rain on this island for about two weeks after the detonation and the winds were light. At the end of the second week after the detonation a heavy tropical storm occurred. This could account for thet observed exposure rate readings after the 10th day being lower than those anticipated by the time "1.2 relationship. Of course, there is no assurance that the exposure rate readings followed the straight solid line drawn between the 2nd and 10th days. It can only be inferred that any deviation would not be of major significance in terms of using the data in arriving at decisions for protective actions, As would be anticipated, the observed exposure rates deviate most from the time-1-2 relationship at longer periods after the initial deposition ~ but these would be less crucial times, That is, the radiation exposure rates would be considerably less than at early times and more time would be available to evaluate the situation, make decisions and take action, DOE ARCHIVES In brief, this was the pattern of fallout after the BRAVO event. What decisions were made and on what bases, how were the decisions carried out and what were the results of these actions?