ye + - 411458 UNITED STATES ATOMIC ENERGY COMMISSION WASHINGTON, D.C. 26545 pug 22 ‘74 Mr. Lombard Squires, Chaircan A poe meme TS lee EY . Genesal ouaviscosy Com cLttee to the . . . 4 . . U. S. Atomic Energy Comaission Se a VP OREN me Veale bbaeane he* ~ ' Dear Mr. Squires: The Commission has recently determined that the following information may be published without undue or unreasonable risk to the common defense and security: 1. The fact that the thermonuclear fuel used in the Mike test (10/31/52) of the Ivy series was liquid deuterium, 2. The related fact that complex and bulky cryogenic equipment was associated with Mike. 3. The fact that the device fired in the Bravo test (2/28/54) of the Castile series used lithium deuteride as 4. its thermonuclear fuel. The yield of the King test (11/15/52) of the Ivy series was 500 KT. Accordingly, this intormation has been declassified. been coordinated with the Department of Defense, This action has Sincerely, BEST COPY AVAILABLE . “ - Taare aoe NEON YE COMBS OT | | Colonie Box s— a Settee J 2p _- ere. ue tO COL. Marshall, Director Division of Classification tahonAiane 1a@£5 | JOR Q Folder on ' a8 ff t os Gk) _