There were two principal types of visitors to the proving ground during Operation CASTLE, the first being the Official Visitor Group, which consisted of approximately 20 people, ten each selected by the AEC andthe DOD. tensibly, the requirements for participation in this group were: Os- (1) A high- level individual, either civilian or military, engaged in some phase of the Atomic Weapon Program, (2) The individual had a definite need to know the over-all program, (3) The individual was Queen cleared. The second group, Participant Observers, was established primarily to satisfy the needs of SWC (Special Weapons Command) and SAC (Strategic Air Command) in allowing certain of their key personnel to witness a shot. In addition there were visits by representatives of SFOO and AEC Washington in a semi-work status. Many of these visitors (all categories) arrived at the proving ground aboard Special Air Mission flights but did not return with the sameflight. Others arrived aboard regular MATS flights. In the handling of these visitors, TG 7.5 was made responsible for all AEC people (except VIP's) who did not come and go via the same SAM flight. Since the number of visitors of this kind and their plans were not known in advance of their actual arrival, TG 7.5 found itself somewhat handicapped in arranging the necessary accommodations and catering totheir wishes. It was noted, too, that the standing of official visi- tors during CASTLE, was, in many instances, below the standard contemplated when the visitor program was established. Since the on-site briefings approached a Top Secret classification, the conclusion is that many people received information as members of a visitor group-‘which was far above a level which could be justified on a need-to-know basis. 2.2 RECCOMMENDATIONS In connection with Task Force organization, it should be noted that, although the operational phase was changed completely immediately after the first detonation, the rapid solution of the resulting problems indicated that the organization was quite satisfactory in its flexibility. It is thought, however, that TG 7.5 should provide more extensive assistance to TG 7.1 in the fields of administration, planning and support. By relieving both the LASL and the UCRL of a maximum amount of non-scientific functions, it is believed that these tasks could be combined in such a wayas to effect some economy in personnel strength and minimize opportunities for conflicting procedures. It is contemplated, therefore, that the SFOO will, with the assistence of Holmes & Narver and appropriate Laboratory eleménts, undertake further study of administration, planning, and support functions for TG 7.1 and TG 7.5 prior to the next off-continent test operation. In connection with overcrowding of long-range communication facilities, both ashore and afloat, it is recommended that appropriate Task Force and Task Group elements and SFOO communications personnel make a joint study of existing conditions with a view toward submitting their recommendations for improvement thereto well in advance of the next operational period at the PPG.