0018933 The radiochemical work reported as being done at LASL was performed in conjunction with diagnostic measurements en the events, The methods used were those reported in the Los Alamos compilation of radiochemical procedures (Reference 66), The gas samples were analyzed for Kr88, xr85, xr85m and in some cases for Xe!33, The rare gas radionuclides were separated from the con- stituents of the atmosphere and then counted in a gas counter, The separation procedure used was developed at UCRL, Livermore, under the direction of Dr. Floyd Momyer, Carrier amounts of inactive Kr and Xe were addedto the air sample and the mixture circulated through a series of traps for purification purposes, Water and carbon dioxide were condensed out in the first trap, which was filled with inert packing and held at liquid nitrogen temperature, The Kr and Xe were abserbed on activated charcoal in a second trap, also immersed in liquid nitrogen, but the major part of the N>» 0, and A passed through the trap and were removed, The Kr was desorbed by raising the trap temperature to that ef a dry ice-acetone mixture, Further purifica- tion was effected by two more absorption-desorption cycles on charcoal at liquid nitrogen and dry ice-acetone temperatures, After determination of the pure Kr yield, it was transferred to the gas counter. This was the procedure used when Kr alone was the desired product; ined, necessary when Xe was alse determ additional purification steps were 67 PRL SAN BE NO ~ ~ oT