Consider the fission process ^ 239 _ 94 Pu + ^ 1 _ 0 n ; ; ^ 96 _ 38 Sr +^ 140 _ 54…

PHYSICS · Multi-part · A Level · Physics · Nuclear physics · Nuclear physics

Problem

Consider the fission process

^{239}_{94}\mathrm{Pu}+ ^{1}_{0}\mathrm n \;\rightarrow\; ^{96}_{38}\mathrm{Sr}+^{140}_{54}\mathrm{Xe}+ 3\,^{1}_{0}\mathrm n.

The atomic masses are:

^{239}_{94}\mathrm{Pu}=239.052163\,\text{u}

^{96}_{38}\mathrm{Sr}=95.921749\,\text{u}

^{140}_{54}\mathrm{Xe}=139.921610\,\text{u}

^{1}_{0}\mathrm n = 1.008665\,\text{u}

. Take

1\,\text{u}=931.5\,\text{MeV}

and

1\,\text{kW\,h}=3.6\times10^{6}\,\text{J}

. (i) Calculate the mass defect for a single fission event (in u). (ii) Determine the energy released per fission (in MeV). (iii) Compute the total energy liberated if

1.0\,\text{kg}

^{239}\mathrm{Pu}

undergoes complete fission. Give your answer in joules. (iv) Express the result of part (iii) in kilowatt–hours (kW h).

Related theory

Nuclear Fission
Nuclear Reactions
Mass-Energy Equivalence
Mass defect and binding energy
Nuclear physics
Mass-energy relation
Nuclei

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