Neutron moderator: Difference between revisions
Jump to navigation
Jump to search
MR = (ζ ∑s) ⁄ ∑a
imported>Howard C. Berkowitz (New page: {{TOC|right}} In a nuclear reactor, a '''reactor moderator''' controls the flow of neutrons. Moderators are often in the form of control rods, which increase nuclear fission when w...) |
imported>Howard C. Berkowitz No edit summary |
||
| Line 1: | Line 1: | ||
{{subpages}} | |||
{{TOC|right}} | {{TOC|right}} | ||
In a [[nuclear reactor]], a '''reactor moderator''' controls the flow of [[neutron]]s. Moderators are often in the form of control rods, which increase nuclear fission when withdrawn and decrease fission when inserted; a [[SCRAM]] is an emergency shutdown in which all rods are inserted to their maximums. | In a [[nuclear reactor]], a '''reactor moderator''' controls the flow of [[neutron]]s. Moderators are often in the form of control rods, which increase nuclear fission when withdrawn and decrease fission when inserted; a [[SCRAM]] is an emergency shutdown in which all rods are inserted to their maximums. | ||
Revision as of 19:14, 10 May 2010
In a nuclear reactor, a reactor moderator controls the flow of neutrons. Moderators are often in the form of control rods, which increase nuclear fission when withdrawn and decrease fission when inserted; a SCRAM is an emergency shutdown in which all rods are inserted to their maximums.
Moderators and reactor coolants have comparable properties, and, if the reactor design permits, making them of the same material increases safety.
The key figure of merit for a moderator material is the moderator ratio (MR).[1]
where
- ζ = energy loss per collision
- ∑s = scattering cross-section
- ∑a = absorption cross-section
Other desirable properties include high density, chemical stability, and resistance to radiation damage.
Light (ordinary) water
Heavy water
Graphite
Beryllium
References
- ↑ John Bernard, Reactor Physics, Part I, 22.05 Neutron Science and Reactor Physics, MIT Open Courseware
Categories:
- CZ Live
- Physics Workgroup
- Engineering Workgroup
- Chemistry Workgroup
- Nuclear physics Subgroup
- Nuclear engineering Subgroup
- Nuclear power plants Subgroup
- Articles written in American English
- All Content
- Physics Content
- Engineering Content
- Chemistry Content
- Nuclear physics tag
- Nuclear engineering tag
- Nuclear power plants tag