Vp..

Considering all the mass of fissile material (like U-235) is condensed into a sphere. This fissile mass is insufficient to sustain criticality hence the only neutrons emitted from fuel will be a result of spontaneous fission decay. Plot the relative neutron flux as a function of radius and deduce the relative fast neutron leakage from the tank. You may assume the tank walls are neutron transparent. Explain your rationale.