3e2.1 RadiochemicalProcedures Radiochenical determinations of the fission producte were made according to standard published procedures7/which are outlined here. Sr*9 was separated as the nitrate and purified by scavenging precipitations, It was determined ss the carbonate, Yl wae separated as the fluoride, purified by ion exchange, and determined as the oxalate, Zr95 and Zr97 were exchange’ with carrier Zr by use of HF, puri- fied by scavenging precipitations and determined as the oxide, Mo?9 was separated and purified as the alpha-benzoin oximate, It was determined as PoaioO, . Aglll was separated, purified, and determined as the chloride. cd115 was separated as the sulfide and purified by scavenging. It was determined as CaNH,PO . Cel4l and Co144 were separated as the iodate, purified by scavengings, and determined as the oxalate. Yields of various fission product radionuclides were determined relative to the yield of Mo”? and/or 2r?9, The determinations were mde on different samples collected at various distances from ground zero. Comparison of relative yields among these reveals the extent of frac~ tionation which occurred. In the absence of appreciable fractionation the relative amount of any fission product nuclide of interest is then obtainable from the measured fission yield curve. 5.2.2 Results Analyses were made on all adequate samples obtained from the various events. The radiochemical results are presented in the form of R values where R is defined as follows: Ro0= where C. = Cl = C, = C, = C — Bl Cc =. % counting rate at zero time of reference radionuclide in uranium thermal neutron fiesion. counting rate at zero time of radionuclide of interest in uranium thermal neutron fission. counting rate at zero time of reference radionuclide in event of interest. counting rate at zero time of radionuclide of interest in event of interest. Counting rates of a given radionuclide from the event of interest were measured under the same conditions of geometry and absorption as those used in measurements in thermal neutron fission. Counting rates were corrected for chemical yield. By inspection it is seen that an R value of 1 shows a relative fission yield the same as in thermal neutron fission of uranium, a value of greater than 1 shows a higher relative yield and one of less than 1 shows a lower relative yield. Results of the measurements are given in Table 5.14. The precision of measurement ras 10 per 21