General K. BE. Fields, USA, the Director of the Division of Military Application (DMA)—then visiting Eniwetok--brought the Headquarters up-to-date on current thinking regarding the CASTLE plans. At that time he envisaged four detonations--two of megaton (MT) range and two of kiloton (KT) range with only one of the two MT~range shots scheduled for Bikini. The possibility of having to plan an MT- range detonation at Eniwetok, even if very small, was not considered by the Task Force Headquarters at that time to be practical and this was the first notification of this possibility received by CJTF 132. This turn of events was somewhat counter to Headquarters and Service acceptance of the enlargement of the PPG to include Bikini, and it also would jeopardize the very desirable objective of basing the Air Force Task Group on Eniwetok rather than on Kwajalein as had been necessary in the case of IVY. In view of these con- siderations, CJTF 132 requested that AEC immediately submit a paper to the DOD explaining the evolving CASTLE concept. Following this meeting, however, IVY was climaxing with the MIKE and KING events and the matter was not given further intensive study for several weeks, By mid-December, a revised concept had already developed and was ready for presentation to the Executive Agent. By this time the Headquarters had been returned to Washington and both General Clarkson and Dr. Graves had briefed AEC on the new changes arising from the laboratory and developmental work which had been going on all during this period. Out of these new briefings the following Conclusions were tentatively reached: