kat_in_a_hat88
Member
Are there differences between the two in terms of their purpose in the fission reactor? To me it seems as though they both are there to control the speed of the fission reaction...or is there much more to it???
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Moderators and Control Rods (1 Viewer)
- Thread starter kat_in_a_hat88
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The control rods absorb the nuetrons which keeps the reaction rate relatively constant (rather than letting it grow exponentially). They create a situation where roughly one neutron per fission goes on to split another atom.kat_in_a_hat88 said:
Moderators slow down the neutrons. Fast neutrons are more inclined to bounce/deflect off of the surface of a nucleus so slower neutrons actually lead to a greater number of succesful fissions i.e. moderators don't slow the reaction down, they just help it to take place.
Well the moderator nuclei are small ones which slow the neutrons down and don't absorb them. Theoretically, I suppose you could find a material compound which contained a fissionable isotope and an element which could provide moderator nuclei, however, I've never heard of such a combination myself. Heavy water (where deuterium replaces the hydrogen) and graphite are commonly used moderator substances I've heard of (which do not consist of fissionable material).serge said:
yeh, i didnt mean that they're the same compoundKFunk said:
but like that you keep the fuel in or around the moderator?
Because if you want the already slow neutron to be absorbed
you should probably have it close to the remaining uranium
or plutonium right?
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