AbL 80 | -« G sacmam<) 4 No. COMMANDER it IN CHIEF and United States Pacific Fleet e/o Fleet Post Office 8an Francisco, California 26 June 1953 My dear Dr, Bugher: Thank you for your letter of 15 May 1953, and copies of Report NYO-4522 containing the resulta of of the Health and Safety Laboratory of the New York Office on measuring the fallout from IVY in various the world. the ‘two the work Operativna parts of The rapid acquisition of evaluated data and the wide coverage of the Pacific Area made possible by the new aerial survey instruments certainiy provided the type of documentation essential for adequate safety measures incicent to the potential hazards introduced by the first thermonuclear detonation. the From IVY experience in regard to fallout distribution in Pacific Area, it appears that the extensive aertal gurvey conducted during IVY could be greatly reduced during CASTLE. Specifically, I nave in mind aerial survey of only those Areas in the predicted trajectory of significant radioactive clouds and the capability for guch survey in other areas similar to the IVY plan. Naturally tnose atolls in the Marshall Isiands and possibly the Fastern Carolines that lie within a potentially hazardous radius from the test site will require individual surveillance by the aerial technique. Of course, such tentative thinking presumes that the Atomic Energy Commission wili have ; available sufficient ground recording methods such as "fly paper” trays or air maplers for efficient coverage in regions of lesser concern. It also assumes that laboratory analysis in lieu of immediate evaluation of fallout data will suffice for areas exposed to insignificant hazard. Por planning discussions, I suggest meeting at my Head- quarters any convenlent date after 15 July 1953. Although I will have departed for my new assignment by that time, I feel it would be best to arrange future planning details with my successor since any matters related to CASTLE wiil fall within his purview, Thie mtertal contains tion affecting the tes within the