7, IS THERE EVIDENCE OF "DRIP" OF DEBRIS STORED IN THE PPFER ATMOSPHERE BY SUPER BONBS? Method of Study Principal ridtings Analysis of samples from worldwide fallout network. difficult This problem has been made by detonations in this cahntry and the_ USSR.Ifwe attribute what.| is now in the atmosphere,| weekly fallout in November-December 1953 was approximately 0.1% of the|calculated residual activity from this detonation. The mean weekly fallout at] is continuing to diminish all stations With a halflife of perhaps one to two months. MISCELLANEOUS HIGHLIGHTS a. Fallout zecoried by the worldwide nstiwerk, operated on skeleton tasis between tests, was less than 1 d/m/25?/day if December. The origin of the debris is in doutt but tha 89/90 ratio suggests This rate of fallout 1s equivalent to .Cc% per week of tha total residual radioactivity. 2. -_— mee Taking all our data inte censideration, we find we are account for more than 5% of the fission preduct yield from. M Day to the present. A preliminary estimate, based on our samples to date, indicate that present atmospheric storags, cipitated, will contribute about as much Sr7U +o the earth is already present. umabia to__ hen pre- rface as