0018933 The radiochemical work reported as being done at LASL was performed in conjunction with diagnostic measurements on 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, Kr85, Kr85™ and in some cases for Xe133, ‘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 added to the air sample and the mixture ‘pumped fication purposes, through a series of traps for puri- 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 absorbed on activated charcoal in a second trap, also immersed in liquid nitrogen, but the major part of the No» 02 and A passed throughthe trap and were removed, Residual air was desorbed at -80°C ahdthe kr by subsequent werming to 10°C. : _ Further purifica- tion was effected by two more absorption-desorption cycles on charcoale : 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; additional purification steps were necessary when Xe was 2lso determined,