2. Avoidance of inadvertent contamination of populated islands or transient shipping 3. A rapid evaluation of the relationship between forecast and actual cloud travel utilizing aerial tracking of the fallout radiation cloud. Initial radsafe planning was based on the limited Pacific Proving Ground (PPG) experience. Only Il nuclear tests had occurred in the Pa- cific and of these only 2, during Operation IVY, were large-yield devices. The IVY experience did not indicate the widespread radiological contamination that could be caused by a large-yield weapon. BRAVO, the first deto- nation in Operation CASTLE, contaminated the shot islands to the extent that one observer concluded "Operation CASTLE must be reported as the nightmare of radiological safety test operations" Nevertheless, (Reference 17, p. 6).* the organization and planning proved flexible enough to accommodate even this unanticipated major radiological contamination and the additional precautionary meaSures and monitoring efforts that necessarily ensued. No personnel were allowed to live on any part of Bikini Atoll throughout the remainder of the test series, but were housed at Enewetak and aboard the task force ships. Access to the Bikini Atoll was restricted to those with official duties, and lengths of visits were controlled, The radsafe planning and safety criteria used by CJTF 7 and the task units, as they evolved to meet the objectives of CJTF 7 during the opera-~ tion, are the subject of this chapter. RADSAFE PLANNING Radiological safety was a major joint task force concern during the planning and operational phases of the CASTLE tests. Original planning * The author of this comment, after an additional 25 years experience in the field of radiation protection, no longer holds this view, but rather states that the radiological safety problems of CASTLE presented a challenge in protecting the 17,000 task force personnel that was admirably met (Reference 18). 75