APPENDIX B RADIOLOGICAL SAFETY This appendix deals with the radiological safety activities and organization during Operation CASTLE. For the most part the problems encountered in this field will be recurrent in future op- erations but the CASTLE experience will fortify the radsafe planners with necessary solutions to many of the questions which will arise. In some respects radiological safety during Operation CAS- TLE was atypical as compared to previous overseas tests. The unique characteristics of the test itself created problems which had no previous counterpart and thus the radsafe planners had to rely on the flexibility of their planning and the capability of the Task Force to meet each situation in turn. The appendix is organized into three broad parts. PART I discusses the aids which are available to the radsafe planners for predicting and determining fallout. PART II outlines the radsafe organization for Operation CASTLE and PART III discusses those radsafe problems, in both the planning and operational phases, which faced the Task Force. PART I Fallout Forecasting Aids. In performing the significant function of forecasting the pro- bable radiological fallout following a detonation, the radsafe personnel have certain tools or aids which are available to them. In general, these aids are closely related to and dependent upon weath- 180