Explore BrainMass

Mean Free Path & surplus Uranium

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

See the attached file.

(g) Define 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 o = 0.66 barns.
What are the consequences for the spacing of the fuel rods in a PWR?
(Please see the attachment for the rest of the information.)

(h) 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.

Please see the attachment for correct formatting and complete questions.

© BrainMass Inc. brainmass.com March 22, 2019, 1:32 am ad1c9bdddf


Solution Preview

The mean free path is the average distance travelled by a moving particle between successive collisions which modify its direction or energy or other particle properties.
Mean free path,
lambda = 1/(N*sigma)
cross-section, sigma = 0.66 barns == 0.66*10^(-28) m^2
N = atomic density == molecules or atoms/volum
For water, N = density of ...

Solution Summary

In first question, mean free path for thermal neutrons in water is estimated. In second question, surplus uranium produced in a breeder reactor is estimated.