. ory atts io ™ ante Tilak “ oe eS mnnerrwws oe a ei teat ina aan, a ~_ OE en Po Dee. er Cine ABSTHACT The radioactive fall-out from tower shots of TUMBLER/SNAPPER (R) and UPSHOT/ENOTHOLE (R) Test Operations has been plotted in detail utilizing the radiological monitoring logs of the ground and air monitors. The report brings out the following points: a. There is no excessive radioactive fall-out from an atomic bomb if the fireball does not touch the ground. (This refers to the maximm fireball radius.) b. | It is possible to datonate the following type of shots regardless of weathar conditions (other than rain) without producing excessive radioactive contamination: 3 NT bezb exploded from a 300 ft tover, 8 XT from 100 ft, 18 XT from 500 ft, 45 ED from 700 ft, 100 ET from 1000 ft, and 200 ET from 1300 *%. Im this discussion only the residcal radioactive contamination 13 considered and no account is taken of the blast and thermal damage pacameters., a. It ds possible to dalineate the general fall~out area adequately using a aizple Stokes’ Law analyois of the winds and assuning that the particle size varies from 150 aicrensa to 75 aicrens, and the average density of the particles is 2,5 grams per cubic centineater. | a. The radex based on tha actual wind observations made three hours pricr to shot tine indicates the general fall-out area ade-~ quately. It is suggeated that the decision to fire a contaninating tover shot (i.e. where the zarimim fireball redius is equal to or greater than “