Question

Problem 2) Suitcase Bomb
Calculate how many grams of Plutonium-239 would be needed to build a ’suitcase bomb’ with a yield of 2 kilotons. Assume 3 neutrons are generated per fission, that every atom fissions, and that each fission produces 212 MeV.

Answer 1

A yield of 1 kiloton is equivalent to of energy thus a yield of 2 kiloton is equal to of energy.

Also

Thus net energy required in MeV is,

Also 1 fission produces 212 MeV.

Thus number of fission's required is

and thus N number of atoms are required for it and converting it to moles we get,

Thus the grams of Plutonium atoms required will be,

where 239 is the atomic weight of Plutonium

is required for the sitcase bomb yield of 2 kilotonnes.