continuity of operations and for economical, expeditious support of Operation REDWING, scheduled for the Spring of 1956. f. Prior to firing NODE somé concern was voiced as to the possi- bility of causing a destructive tsunami (tidal wave) of dangerous proportions since the device was positioned on the edge of the reef. prior to firing MIKE during Operation IVY. This same question arose In both cases it was disconcerting to the commander to have this question raised by scientists just prior to shot time. In both cases after study, the task force scientific director assured the commander that under the specific conditions of the particular test involved a tsunami would not occur. This question will continue to arise with certain high yield detona- tions until suitable tests are conducted to resolve the problem. METEOROLOGY 17. As in previous operations, weather was a major problem, particularly with regard to winds aloft for fallout considerations, of unacceptable fallout patterns. Delays were experienced because The tests were carried out during a period of the year when the weather in the Marshall Islands area was reasonably favorable; it was not an unusual season from a climatological point of view. Future tests must expect similar delays due to weather unless firing techniques such as firing on barges in the open ocean or air drops are developed which will minimize the amount and the activity of fallout. RADIOLOGICAL SAFETY 18. During CASTLE it was more important than on previous tests to make cer=- tain that populated islands and transient shipping were not contaminated since the detonation of six weapons and devices were planned with ylelds expected to be in the megaton range. The lack of fallout information from previous shots of megaton yield weapons or devices_was_a serious handicap. !' ‘ DELETED Consequently, nore radioactive debris was carried up and diffused over a much larger area than was thought possible. [MMII-nonstrated that the origin of the fallout pattern is a large area up to fifty miles in diameter, varying according to the yield. The radioactive intensity of the debris, likewise, varies with the yield. Ree Ccopied/DOE LANL, J-Div. | Oy