This preview shows page 1. Sign up to view the full content.
Unformatted text preview: to avoid a sudden energy release (Wigner effect). 3. List five desirable properties of a moderator for a thermal reactor. Explain the importance of each property. Solution: (a) It should have a small A number so that it can thermalize neutrons with relatively few scatters. (b) It should have a small absorption cross section and a large scattering cross section over all neutron energies to avoid nonfuel absorption (to maximize f) and to promote thermalization by scattering interactions. (c) It should be relatively inexpensive and easily incorporated into the core (d) It should not change phase over the anticipated range of core temperatures to avoid the need for expensive pressure vessels. (e) It should be chemically stable to reduce its longevity and prevent possible accident conditions (f) It should not absorb neutrons to produce unwanted radioactivity. July 24, 2002...
View Full Document
- Spring '06