20.14 (a) Show that a megawatt per tonne is the same as a watt per gram. (b) Because most nuclear power plants are base loaded, the power is constant and the product of the flux and fissile atom concentration is likewise. Show that the burnup is given by the formulas = 235 ( 0 ) = 235 ( 0 ) ( ) B= U w f N 235 ( 0 t) = ( M u N u ) w f N 235 ( 0 t) (c) Calculate B for a three-year fuel cycle having an initial atomic enrichment 235 ( 0 ) / = 0.03 N 235 (0)/N u =0.03 and flux 0 0 of 2 1 0 13 / ( 2 ) 210 13 /(cm 2 s)