(a) De?ne the 'mean free path' for a neutron in a material.
Water is used as the moderator in a PWR. Calculate the mean free path of a thermal neutron in water given that the absorption cross section for thermal neutrons in water is σ = 0.66 barns.
What are the consequences for the spacing of the fuel rods in a PWR?
You may assume the formula λ = 1/σN and the density of water ρ = 1000kg m-3
(b) A breeder reactor operates at a rating of 500 MW per tonne of 233U.
What other element is required for the production of 233U in the breeding process?
If the breeding ratio B = 1.16, and the reactor is run for 10 years, calculate how much surplus 233U is produced per tonne of 233U consumed assuming an energy release of 200 MeV per fission.