'. , @e «Me baste for for vhere fall-out will go is e gaineé frok oversesa test operations , SANDSTONE, end IVYand. to 2 certain stem’ from tests of the Novnda Proving Ground. Price to the firing of BRAYO;cnly one megaton yield daviee (IVI-MIEE) hed deer q | detonated. Although conseientious efforte were made to decunem® the qué from MIKE, only abouts 3% of the . ‘Se. The most probable value of the yield from BR570 we predicted to be three to fiveanegatons or one half the value of the IV yield. The upper lint of eight megatonae =O" yield was considered to be of the ordep of =—” . . ¢, The surface radex was plotted, with a insurance factow added, i.e., smaller particles than previcus experienes indicated necessary were considered, This doubled distances from ground sero were fall-cut. me predicted to cecur. 4. The upwind intensity of radiation levels at various distances was considered te be the same order of maguitude’ as for IVY-IKE, Radiation versus distance lines were transposed to BIKINE Atell, e. A critical problem in predisting fall-out involves forecasting the stability or lack of stability of the wind pattern after shot tine. Since radioactive particle travel, is determined primarily by the winds at each level, it is required that winds mist be from fayorable directions or varying within the outer limits on favorable directionea during the time of fall-out. The critical fall-out period was considered ta be on the order of twelve to eighteen hours for significant fall-out toe occur. The variation in time arises from considerations of wind shear, wth sore K-16