The composite neut capture decay curve will then be the sum of the decay curves of vest, eo, Np239, u240, and Np240 , 1.@., Ae = Ago (02000416270 200431t 4 -1.77t (3.9) F 0.00652—70sOL24t 4 0.014600 00495t yx where A, = Activity due to capture products at time t and Agoz Proportionality constant Aco can be determined from the ratio of neutron capture to fission activity measurements. 1239 9 TABIE 3.1 ~ Initial tive Ac ties of 237 U ’ v Np239, By) » and Ngee The Shot 1 decay curve will then be the sum of Eqe 304 and Eqe 3e92 The experimentally determined ratio of uranium capture products to fission products can then be used to find the value of Aco if it is remembered that Ayr has already been determined. A,|250 Ay¢ (250) ~ = 0.8 (3.10) 068 Ayp(250)“H a Ag (Ecye 4") (3.11) The curve was then normalized (set eoual to 1) to 400 hours, at which time the activity data were knowne The equation for the extrapolation of fission and neutron induced activities to sampling time is then A = 1350 7226 4 2200(0,000z16e70-00431t (3-12) f en~Le77t40 0065207020124bto 0146070 00495t ) This composite curve is showm in Fige 3ele * The last term includes the activity of both U 39 240 and No 240