A town has a population of 1 million. The average electric power needed per person is 300W. A reactor is to be designed to supply power to this town. The efficiency with which thermal power is converted into electric power is aimed at 25%.
(a) Assuming 200 MeV of thermal energy to come from each fission event on an average, find the number of events that should take place every day.
(b) Assuming the fission to take place largely through 235U, at what rate will the amount of 235U decrease? Express your answer in kg per day.
(c) Assuming that uranium enriched to 3% in 235U will be used, how much uranium is needed per month (30 days)?
(a) Energy radiated per fission
Usable energy or efficient energy per fission
Total energy needed
No. of fission per sec 
No. of fissions per day
(b) No. of atoms disintegrated per day
235g of 235U contains 6.023× 1023 atoms
324×1022 contains 
(c) 235U needed= 1.264kg/day that is 3% of uranium sample.
So, uranium needed per day
Uranium needed per month