The very nature of the weathering factor makes this a diffiewlt ¥ parameter to evaluate, The probability of occurrence of precipitation and/or winds and to what degree has to be estimated as well as their ffects on radiation levsls. Leaching effects were studied on sails about 120 miles frou ground caro where fallout had occurred during Upstiot-fnothel>. Dese rata readings were insignificastly levar Shacn those predicted by radiological decay according to q71s2 after a period of more than one year. One example of the effects of winds was obszrved during Upshot-Knethole. The fallout from the March 17, 1953 dstonstion vas in a lous narrow patiern wah. ee to the east ef ground 26506 Tre sacoud Gay after fellout a rather streng surtace wird bicw o aleost at right angles across the crea, Ler about a perdod of 2 day. ey oF Dose vate readisgs were teken on the first end fourth days at the some locations cnd then were compared. The fourth day done retes were Jess, by factors of thrse to six, then thase “o be expected fron the Phust dys readings, based on rete ef dscuy oF Tallout menisrements indicited thet ihe reic of © chee (0° ar of this Saplout materiel ves not significantly diffvsrent fren tt) Bearurs of tle yuxrsicel conditions descriked above, these redux. i in contunination probably are near the upper limit to be expectec 41 wind. Operational Feasibility of Crit. It is not the intent here to discuss operat:-.:21 procedures, but it should be indicated that the computing of red’ ton doses as reccn= mended in Criteria I is a not too difficult tesk. if one assuies a tl? rate of decay as a first approximation, then a single graph of dose rates versus times after detonation can be c. .:ctructed that will