-9- events were chosen because the fallout documentation was adequate to reasonibly determine the exposure rate-distance curves and the fallout fractions. Their yields ranged from 1 te 92 tons, fallout fractions a factor of about 3, and tower heights from 25 to 72 feet. Fallout hodograph shears ranged from about 2° to 30°, mean wind speeds from 2 to 29 knots, and initial cloud tops from about 2900 to 9400 feet. The normalized exposure rate-distance curves are shown in Figure lywhere the maximum separation between any two curves is seen to be a factor of about 2.2 at one mile downwind, with less separation at all greater distances. Normalized exposure rate-distance curves for the four excavation experiments, Jonnnie Boy, Sedan, Teapot Ess, and Danny Boy are shown in Figure 2. The range in totai yield of those detonations was a factor of about 240 and the range in fallout fraction was a factor of about 13. Observed wind speeds, shears, and cloud heights, as expressed in the scaling equations, also varied considerably. The separation between the normalized curves is a factor of about 3 at shorter distances, decreasing with increasing distance to a factor of about 1.8 at 120 miles downwind. Only two cases of ventings of underground @tonations designed for complete containment aré available which are reasonable analogues. Pike and Pinstripe everits. Both ventings were of short duration and had rather similar early-time cloud rises. Yields, as well as fallout fractions, differed by about one order of magnitude. we STM END tn. 4 similar. These are the Shears and mean wind speeds were The normalized exposure-distance curves for these two events are shown in Figure 3. A maximum separation between the two curves is a factor of about 2.6 at a downwind distance of 80 miles, however, the separation