-CONFIDENTIAL This document consists of Copy No, -* Bas of ui 2 pages Series —* goRB | SECURITYINFORMATION UNITED STATES ATOMIC ENERGY COMMISSION WASHINGTON, D. C. June 12, 1953 Honorable Robert LeBaron Chairman, Military Liaison Committee to the Atomic Energy Commission ae Dear Mr. LeBaron: Reference is made to our letter of January 2, 1953* which outlined the CASTLE Operation as we contemplated it at that: pre- liminary stage, Since that time in the process of further developIMent and test, it has become apparent that, if feasible, the scope of CASTLE should be increased in the interest of assuring the , resolution of factors bearing on emergency capability weapons and special material requirements. At this stage, we believe a program of six shots would assist materially in the above, and, accordingly, we have been working with Joint Task Foree Seven-on questions of the feasibility of such a program, From their standpoint and ours, it appears practicable to execute a six shot program and to main-~. tain the proposed timing of CASTLE, provided the Atomic Energy Commission and the Department of Defense accept such a program: and provided the various contributing phases such as special materials production at Oak Ridge_Pemain on schedule. - : Ane a etonate two shots at . “Eniwetokand four at Bikini. The first detonation is seheduled for Fepruary 15, 1954, with seven to ten days intervals between shots. It should be emphasized, however, that the actual scope and plan for execution of CASTLE cannot be fixed until about September, At that time the relevant factors bearing on the merits of the. various proposals and on the operational capabilities and limitations both of material production and of a Task Force nature '*Secretariat Note: Circulated as AEC 597/7. RESTRICTED DATA This docutient contains restricted data as defined in theAtomic Energy Act of 1946, Its transmittal or the disclosure of its contents in any ‘manner to an unauthorized person is prohibited. a Se :

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