sy RHE EAS Te Ramee SEE «Ue MRWineeatitgy ORSA Saale tainrane See ee EES Paeea . hel oteath Ct abs, ve api itt anate Pie Between May 5 and mid-July of this year, Opera tion Redwing was conducted at the Eniwetok Proving Grounds seal in the Pacific. Particular attention was paid to the faliout problem in this Operation and a'major effort was made effort was successful. ‘In addition, considerable atten= ELergy tion was paid to operational factors which would minimize _ world-wide fallout. Thus, the total depositionin ther# stratosphere during this’ Operation was?held borg figure.4 Her Bee AE epee cerstenaeey Operation. In fact,"we estimate at the present time that the total stratospheric reservoir, 3 t counting all sources, isabout ghe gameas it was two &:% years ago, i.e., about 12 mc/mi* of ‘Sr90'or the‘equivalent form world-wide distribution. During the past:two yearst the additional depositions in the stratosphere-have “3 amounted to about 6 megatons eqhiyalent‘of fission produgts total or 3 mc/mi* of Sr90 or Cs437,° This appeans to has compensated approximately for the 10 percent pen year ofz. fallout and the 2.5 percent per year of radioactive decay, In other words, the testing by all countries seems to hays restored the stratospheric reservoir to approximately the mt which is maximized by weapons of higheyield which do natg. puncture into the stratosphere, is increasing. ™ Several’3’ such weapons have been air fired abroad in the last months. This material, for the reasons explained above, descends. rather rapidly but all the way around the world ‘in the “= same general latitude as the firing site. Thus, though * it is difficult to estimate, it appears that yaa amounts: to perhaps 5 additional mc/mi2 of 5590 and Csi34 in the | U. S. Adding to this about 4 mc/mi* for the world-wide me/mi* for stratospheric fallout, -1 would estimate at tropospheric fallout from the Redwing Operationand 1 present that a total of about 22 m.. ni* (more) . — See .The latitudinal tropospheric world-wide fallout, of Sr9Q-is to be BF: fps Re sa¢ By e. oa 3 |5 ote of 24 megatons of fission products calculated ag a unie:.% 24, megaton value of two years ago. Be ses Tas. very considerably less than that presen win theistratoe%h sphere before the —. ae * ae SEP ee OEICSs Wr PRTLSTCn Soil meanentedhratad eT, enhepi aes © to produce a megatonerange weapon with-an inherently <*% smaller amount of fallout for a given energy release. +Phis - = ue Bn rh! . 4h “4 ,? et a ye "2 4 Hs, #5 sae cart tte Rees a eR At the end of 1955 the total: deposition in t upper midwest of the United States was some’ 13 mc/mi? of; Sera In the spring of 1956 this total ‘rose to about 16/ mc/mi*, pt