( | ( winatersd . - 0018933 APPENDIX E Derivation of Formula for Percent Mo Left in Cloud The formula given in Chapter 3 for the percent Mo?? left in the cloud is based on a materia] bzlance for some nuclide, Y,. It can be derived as follows: t Let Y, = atoms Y formed in the explosion e Yo so" Yro ? " Mop, © " left in cloud "in fallout atoms Mo?? formed in, the explosion Mo, = " " left in the cloud Mono * at " in the fallout y * k fraction of Mo?? atoms left in cloud 3 the ratio atoms Y: atoms Mo?? formed in thermal neutren fission, a constant [R9%y)] = R-value for nuclide Y in explosion [R9%y)] cz" | [R9% x] Fo = unt %e =Y¥o+ Yeo = o " " non cloud " at mM! fallout - eovececd 1 (}