Reduced moderation water reactor

The Reduced-Moderation Water Reactor (RMWR), also referred to as the Resource-renewable BWR, is a proposed type of light water-moderated nuclear power reactor, featuring some characteristics of a fast neutron reactor, thereby combining the established and proven technology of light water reactors with the desired features of fast neutron reactors. The RMWR concept builds upon the Advanced Boiling Water Reactor and is under active development in theoretical studies, particularly in Japan.

Source: Wikipedia — Reduced moderation water reactor (CC BY-SA 4.0)