so that the small particles in the wash could settle through without being blocked by large particles, The particles remaining on the sieve were washed with approximately 20 ml. of acetone and dried, These particles were then placed in the Roller analyzer; ail particles below 40’: in diameter were blown over into an asbestos collection thimble, This step greatly _ reduced the number of fines in the larger particle sizes, These large particles were then sieved dry with mechanical shaking for 5 min into 9 size~fractions, The small particles that had settled with the chlorobenzene through the 4h sieve were centrifuged, washed with approximately 20 ml of acetone, and dried. They were combined with the fraction velow LO » that had been separated by the Roller analyzer. (see Appendix B) This entire sample was then separated by the Roller analyzer into 5 size-fractions,. . Particle sizes are reported as mean volume diameters: dy of E04 ay? : 3044.2 Preparation of Samples z ™ a, The various fractions of, the size-graded fallout were weighed, dissolved in 5 ml of conc, nitric acid, and heated to insure complete dissolution, Aliquots of the aqueous phases were fumed to dryness twice with concentrated nitric acid and then with a mixture of nitric and perchloric acids, The final solutions were made up to volume , with water, Aliquots of all solutions were measured for gross activity and decay, Other liquid and solid samples were treated in a similar manners . For the leaching studies a weighed quantity of the solid fallout was placed in a sintered glass crucible end slurried with 10 iL of water for 10 min, The mixture was filtered through the crucible and the filtrate diluted to volume, The crucible was dried at 110°C for 30 min, cooled, and wetghed to determine the wetght of sample removed by the leaching, Subsequent leaches were carried out with dilute hydrochloric acid which permitted greater dissolution of the particles, 33 Radiochemistry yar ang M07? analyses ype performed at the test site; cal Fe°, sro9, Zr99, BalkO, and Celli4 analyses were performed at the Army Chemical Center, Four aliquots of eagh sample were taken for each analysis except in the case of the Na“4 procedure where only one aliquot was analyzed, The reported results are the averages of the four aliquots, The separation procedure fur cr89 and BalhO ts essentially that of Slerdenin, 1/ The only sinificant modification is that the barium is finally precipitated and procedures for zr95, Yo 9, and C mounted as the chromate, The are the methods empleyed by the. Radiochemistry Group J-11, Los Alamos Scientific Laboratory, iz/ The act and cad analyses were developed by these Laboratories and are 23 SECRET — RESTRICTED DATA : ;