catmameammentin Ohepeepenrenenneans - cS 7 - i, Unit ouU sintey 9/ ATOMIC ENERGY COMM SION WASHINGTON 25, 0. C. November 1, 1952 TN. TTT) The Atomic Energy Commission wishes to réport that at 0715 Novenber 1 (1415 October 31, Washington tine), the first full scale nermonuclear experiment was conducted successfully at Eniwetok. You will recall that we discussed certain aspests of this operation with you on June 30, at wnich time Dr. Norris 5. Bradbury, Director of the Los Alanos Scientifio Laboratory, described this partioular experiment in sone detail for you. From early and incomplete evaluation of results, the yield is estimated roughly to have been more than 6 megatons, possibly as high as 12 megatons; that is, 6 to 12 million tons of ThT equivalent. In conmparison with atomic bombs of the Hiroshima type, this is equal to some 50 to 76 in terzs of destructive effeot. I? the rore présise and lengttay methods of measuring yield, which are now in pros os, confirm the atave yield, the detonation exceeds what we had anticipated. ‘re are confident even now, however, that the principles of the recent discoveries thst opene o Vay accelérated thermonuclear effort, can be applied in full scale devices. The shot island Eugelab is missing, and where it was there is now an underwater crater of sone 1500 yards in diemster. No significant fall-out of radioactive contamination occurred. As a precaution against fell-out, Joint Task Force 142 had evacuated Eniwetok Atoll for the shot. They expect to return to the atoll today. Unfortunately, during the cloud sampling operation one aircraft, “" “an P-84-G, "end pilot, were lost in Enivetok Lagoon. . ’ Otherwise the principal operational missions were conducted without incident and as plamed. * ~ 467 Von r Do. Se Gur present plan calls for the conduct of the sesond and final detonation of this opsration not earlier than November 11, Eniwetok time. Actual ‘conditions ensountered on reentry to Eniwetok ray, of course,~ cause -elaybeyond this date. This detonation will be a proof-test of -a one-half mesaton fission bomb dropped from aB-S6 aircraft. cordon Dean hairrean — Departmert of Energy Historiar’: “fficg ~ = pb \ARCHIVES “