DNA 1240H-2 3. Activity is homogeneously distributed in the base surge. 4. There is no fractionation of fission products; therefore, ganma decay rates used are those for the gross fission-product mixture. 5. Possible deformation of surge by wind is neglected eo that the surge has circular symmetry. Beginning at 15 seconds after buret, the surge moves downwind as a unit at the specified surface windspeed, u (ft/sec), and at t se at a distance u(t - 15) ter burst, the center of the source is located downwind from surface zero. 6. Total activity due to the burst is mltiplied by a number #, O< $< 1, that depends on scaled depth but does net varyswith time. ‘This assumption is equivalent to assuming that a fraction ¢ of the total activity is the- base surge (given conditions 2 to 5}_and that there is no loss of actinizy.by rainout, evaporation, etc. se B. Classification of Underwater Burst Depths - “ / 3 A given underwater burst of yield Y (KT) at a depth of ¢ ft is classified as follows: #7 Very Shallow: 22 Y/3eae7s y¥/3 Shallow: 75 y}/3€ae2ko yV4 Deep: 2ho ¥2/4< geso0 y/4 Very Deep: 600 yi/4 <a Near-Surface shots, O<d“2l] yi/3, are not covered by the model of Ref. 48. Figure 17-9 (from Ref. 49) shows the categories for 1 to 100 KT. tests falling in the four categories used are: Weapon Very Shallow: Crossroads Baker Shallow: Herdtack Umbrella Deep: Hardtack Wahoo Very Deep: Wigwam Table 17-2 gives the yields and depths of these shots. as rodtoeiy ® ical interpretation of the classification, *P , from Ref. 49, , is Near-Surface bursts are those that are so shallow thet the layer of water above them is vaporized by the explosion. The phenomena of this type of burst and the associated hazards ere unknown. The radiological REST AVAILASLE COPY 17-42