Under-moderated reactor
= Under-moderated reactor
A <nuclear reactor> on the side of a specified moderation optimum where adding moderator increases neutron multiplication. Removing water then tends to reduce <reactor reactivity>, under the comparison's other fixed conditions. The optimum and the derivative depend on composition, geometry and operating state.<Nuclear Physics and Reactor Theory, Volume 2 by the United States Department of Energy>[Module NP-03, pp.24–25, Moderator Effects]{ref}