~6for centainnent-designed detonations it is the practice to assume that f' = °C. Thus, if metcorological conditions and radioactive cloud dimensions were identical for thé analog and new events the predicted exposure rates would simply be proportional to fission yield. <A discussion of the subjective estimation of the vertical cloud dimension (n') and a detailed description of the mechanics for obtaining values of (V') and (6') are given in reference 5. The initial result of the ecaling process ‘is the predicted H+] hour gamma exoosure rate levels as a functionof downwind distance along the fallout hotline. To obtain exposures, an appropriate radioactivity decay rate is applied to'the H+l hour exposure rates. If significant quantities of eee induced activities are involved, their potential effect on the gross gamma decay rate must be considered. Estimates are also made of the inmersion exposure occurring during cloud passage along the fallout hotline. - These estimates are made on the basis of the relative contribution to centerline exposure from cloud passage and fallout observed with the analog event. It is assumed that the relative contributions as a function of downwind distance for the new event will be similar to those of the analog event.. Dose rate profiles from the routinely applied analog have been examined and current practice is to assume an infinite fallout to cloud passage centerline exposure ratio of 2:1. The exposure during cloud passage includes contributions from both the airborne debris and the debris deposited during cloud passace. This provides an estimate, for example » of the exposure which could be avoided by evacuation prior to cloud passage. This ratio would, of course, be altered if the new event decay rate were significantly different from that