1. The problem statement, all variables and given/known data 2. Relevant equations Working at a rate of 1.204 x 10^22 fissions/s, what fraction of that 70 kg mass of Uranium will be fissioned during the 550 days of fuel installation? (Fuel rods are replaced appx. every year and a half) 3. The attempt at a solution 1.20x10^22 fissions/s = 1.0368 fissions/day 550 days = 5.7x10^29 fissions 5.7x10^29 fissions = 225376210.5 grams 225376210.5 grams / 70 000 grams = 3219.66%. Which is incorrect.