RMI Nuclear Justice Documents

80 RADIATION STANDARDS, INCLUDING FALLOUT Placard 16 shows the North Pole on the left, Equator on thecenter, and South Pole on the right, and the altitude in thousands of feet on the vertical scale as before. The tropopause is shown by the lowermost line. The stratosphere is divided into a series of zones. It is argued that in each zone the fallout will behave more or less the same, but fallout may be different from one zone to another. Considerfirst the lower polar stratosphere. This would correspond to injections from Russian tests with yields up to a few megatons. Second, zone B is in the lower equatorial region. The Christmas Tslandtests in the lower megaton range will add debris here. Finally, in the very high atmosphere is a zone where rocket tests may be inject- ing their debris. . Our predictions are largely based on extrapolations from previous experience. . Placard No, 17 displays the North Pole on the left, the Equator in the center, and South Pole on the right. The relative amount of fallout is shown on thevertical axis. For injections into the lower polar regions, the upper curve shows that most of the fallout is expected to take place in the 30° to 60° band and almostall of it in the northern hemisphere. For the Christmas Island tests, the stratospheric componentis expected to partition equally between the hemispheres and peak in the 30° to 60° bands of both hemispheres. For very high altitude explosions, those which inject debris to hundreds of thousandsof feet of altitude, the geographical pattern will be about the same as the lower equatorial pattern, except that the levels would be somewhat lower because of its longer residence time. Further, there will be more time for radioactive decay and there should be virtually no short-lived isotopes. Placard 18 shows the relative deposition for. successive years after the time of injection. The horizontal scale is the number of years after the injection has taken place, and the ticks indicate the winter, spring, summer, and fall. The bars indicate the spring zone of each year showing the predicted maximum in each spring season. The injections made in the lower polar stratosphere show a very marked peak in the first year and a decreasing fallout in successive years. After 4 years there won't be enoughfallout to be measurable. The injections made in the lower stratosphere from Christmas Island will fall out in much smaller amounts in the first year but will take much longer time to be deposited. Maxima will occur in the spring seasons perhaps as long as 9 yearslater. _ Andfinally, we can compare the lower equatorial stratosphere with injections from the very high altitude on placard No. 19. This placard shows a peak in the first year for the lower equatorial injection andat the same time practically no material was brought down to the ground fromthe high atmosphere. In later years nuclear clouds placed in the high atmosphere may actually produce more fallout than from clouds in the lower equa- torial stratosphere for an equal injection. I would like to conclude bystating that we have learned much in the years since 1959, mainly about the nature of the fallout. But I feel that the meteorological profession has not kept abreast of this progress. Ourpredictions, by and large, are based on extrapolations from past experience. . . 253 so leo tu Be pa. eldmea gy ante ghee neathebReeSOPhitAVROR!