July 11, 1951 John C. Clark that should we approach a situation where the question of evacuation micsht come up for active consideration, all of our available pcople will be busy nomitorine, ctc, It will certainly not be the time to have these pGopic woncering about how to gct children, pets, etc, into vehicl.s. I do feel, however, that some organization should carry out specific planning for possible evacuation of civilian groups in the surrounding area. It is absolutely essential that this be done in such a way as to avoid frightening pcople unnccessarily. We do not wish to wear out our welcome or otherwise jeopardize the cordial public relations currently existing. Technically spcaking, this is the sort of thins which should be the responsibility of the Civil Defense organization on a State level, although T doubt if any such organization actually exists. 3. Permissible Exrosure For both Operation Ranger and Opcration Greenhouse we used a pcrmissible exposure of 3.0 r for the operation, If it is agreeable with Dr. Warren, we propose that this same level be used again. Experience in the two recent tests has shown this to be realistic and workable. We do not consider it a calculated risk; restrictive. neither does it appear to be unduly In this connection I might point out that certain workers at Greenhouse actually cot more cxposure from fall-out than from opcrational activities, This situation was totally unexpected, and wes more or less handlud by studiously looking the other way, In other words, workers were not credited with fall-out exvosure in determining the extent of their activities, althouch it meant tiat a number of people came home with quite significant total oxposures. In the cascs of Los Alamos personnel this has been envered in their cxposure records. I do not feel that we can afford to adopt a similar policy again. (‘This does not imply criticism of the decisions madc at Greenhouse). I feel that using the 3,0 r permissible exposure for the operation does not seriously violate the spirit of the AKC directive on this mattcr. Actually we are giving ourselves a little lecway to permit the concurrent beta cxposure which is not measured, there has alrcady been expressed by some of the military groups the feeling that they may not necessarily be bound by the same permissible exposure levels as will be used for other workers; they would like to feel thet they can go ahcad and get higher cxoosurcs if they wish. Certainly IT on my ovm responsibility cannot permit this; and as this operation is being staged fundamentally by the AEC, I fecl that there should be a specific directive covering this matter from Dr. Varren personally, “ue can think of a for rare individual cases whcre leniency might be permittcd, such es the pilot of a jet plane collceting air samples,