not a part of SFO but working closely with the organization, UCRL-~Livermore beganin - - « The progress made in development and in stockpiled weapons during the period would have been impossible without the rate of full-scale nuclear testing maintained from 1951 through the Spring of 1953. Four series, totaling 31 detonations, were held in Nevada, Two series, totaling 6 shots, were held in the Pacific. 3. JULY 1953 TO JANUARY 1954 This was a period of accelerated transition from the six-year organizing and building phase toward a tidied-up, controlled manufacturing operation. It proved also to be a period of major transition in weapons requirements from implosion to thermonuclear with resulting impact on Santa Fe Operations. Decisions were reached or actions were taken which materially affected various phases of the operation. are summarized here, The major developments of the period Future Weapons Production Requirements Operation of five high explosives production facilities at three locations had been planned to meet implosion weapon requirements. By July 1, 1953, this had been "firmed up", and it was planned to complete Spoon River and to expand Pantex and Burlington. The August future production directive made it fairly clear that it would be necessary to complete Spoon River or expand Burlington and Pantex materially. SFOO defended completion of Spoon River both for strategic dispersion and for providing desirable excess capacity for wartime production. In early November the Commission cancelled Spoon River, and it was explained that expenditure of $6, 000, 000 for expansion at Burlington and Pantex would provide sufficient capacity and save perhaps $32, 000,000 at Spoon River. In December it was made known that military requirements for implosion weapon production had been cut drastically in anticipation of thermonuclear weapon production. These decisions reversed the constant expansion since 1947 of the implosion production system and major readjustments became essential. Subsequent redefinition and analysis of military requirements reduced still further the figures for highexplosives production. As a result a study was in progress at year end to determine the need for Inyokern, Burlington, and Pantex with a very real possibility that only one plant (or low production at two plants) would be needed. There was no change in the established requirement for thermonuclear stockpile production. The schedule had provided, however, for meeting only approximately onethird of the 100 per cent figure. This was subsequently increased to two-thirds, and, paralleling the high explosives decisions, was placed at 100 per cent. in the thermonuclear field was, of course, requisite. Spoon River Plant Expedited action Al CO $A Mice The former site of Camp Ellis had been selected. Recalling the impact on their communities of the quick buildup and quick deactivation of Ellis, the Illinois region was lukewarm or cold to the AEC project. Assured that the plant would bring the same advantages 14 fy 19