What does nuclear moderation accomplish in a nuclear reactor?

Nashville

Chemistry.



Cottage City

A moderator is used to slow down neutrons. Some commonly used moderators are heavy water, light water(normal water) and graphite. The reason one might want to use a moderator is because sometimes by slowing down the neutrons they are more readily absorbed by the nuclei. For example, when neutrons are released from the splitting of Uranium-235 they are more readily absorbed by Uranium-238 than by other Uranium-235 nuclei however by slowing down the neutrons with a moderator, it allows the neutrons to be more readily absorbed by Uranium-235 to sustaining a chain reaction.



Garden City

I'm no nuclear physicist, so my understanding is rudimentary, but without moderation in the form of more/less fuel rods, water containment/cooling and rods used to absorb neutrons, the reaction could easily get out of control and lead to a melt down situation.