‘ J~3/903 SUBJECT: ey ana: =! Cs: copy | Radiological Hazards in the Marshall Islands Area During Operation CASTLE 4. Although the items in question are not ocrogrammed as special operations during CASTL=, certain other aspects of the radiologica. safety plan to rrcvide a reasonable and safe compromise. Specifically, these are as follows: a. Reference cloud tracking, an effort will be made to determine information relative to the forecasting of heavy secondary fall-out on the shot site. This will be accomplished by a small number of WB-29 flights up-wind from the shot site to a distance of approximately 600 miles. Since the up-wind direction will, in general, be toward the, populated atolls, minor modifications in aircraft tracks should provide sufficient information on conditions in those areas. Also, certain specified aircraft operating in the area of the tests after shot time will be in positions to provide reasonable indications of actual cloud movements. In addition, as on Operation IVY, the Task Force Commander will issue pre-shot forecasts of cloud trajectories and fall-out areas and will continue such advisories with post-shot analyses of the sources of information available. b. Reference drinking water sampling at distant atolls, existing equipment could, on a limited basis, be diverted to such a post-shot effort in the event cogent and compelling reasons arose requiring such action. Past experience indicates, however, that such action is necessary only under extreme conditions. c. Reference evacuation of native populations, no task force equipment will be available for such an operation. Consideration of populated islands will, however, be one of the major factors in the Commander's decision to shoot, and will be considered in its relation to forecast winds and fall-out predictions. 5« This command is constantly faced with compromise between the necessity for certain efforts and the limitations of forces and equipment available to accomplish objectives. Your comments or suggestions in consonance with the above are requested in order that task force planning may be realisti C ang dad Mutually mutuall agrees reeable t oO 4d 11 concerns d FOR THE COMMANDER : My OQ od oao°28 0 Wo mt ED On o. bd ” = © woo Wg ROBERT H. CUSHING Colonel ft USA Hip fF N Actg Chief of Staff COPY Doerr ay 3 ol oa a lh RI x P| « ity 2 we) ac . 32> © 2Oy me oe AAA ~~ “ < ZZa< ~ G % © me a w ¥ ay pomARCHIVES| oe mee TW Qty CQ SC ne a