>>11978215Did you read any of it?
>Common misconception. It's sort of both to slow them down and speed them up.Control rods are solely for reducing reactivity, and anon is claiming that they aren't. Instead, anon claims that control rods are for "speeding up" neutrons which is wrong no matter which way you look at it. You can't speed up a neutron by collisions with any part of your reactor unless the neutron in question is somehow below the average thermal energy (like 0.025 eV, compared to the millions of eV they are born at from fission)
>When the slower moving ones hit a nucleus, they just get absorbed, forming an unwanted isotope that poisons the reactor. When the fast ones hit a nucleus, they only ricochet off and generate unwanted heat. For actual fission to happen there needs to be a sort of resonance between the neutron and the nucleus, which only happens at a specific range of energies.This is explicitly wrong, as I pointed out by showing actual data on nuclear cross sections. Fission is most likely at the lowest energies possible, hence we want to slow neutrons down as much as possible by scattering them on the moderator. Anon is trying to say that some intermediate energy is optimal, which is not true by any interpretation.
>Moderators both capture the fast and slow moving neutrons depending on the material they are made of and how long they are, so raising and lowering them controls the proportion of neutrons that permit fission.Anon implicitly states that "moderators" are control elements/control rods, which doesn't really make sense. The "moderator" in a nuclear reactor is just the water (or heavy water, in the case of CANDU reactors, or other materials in more exotic designs) and isn't any specific component you can point to.
>So you're half right, they regulate the reaction, just not in the intuitive classical sense of slowing fast moving things downNo, it is in the intuitive sense of slowing things down.
