Reactor

Object: To provide a reactor, which is excellent in fuel economy, which is high in average power density of core, and which is high in stability. Structure: About 90% of energy emitted from a fuel assembly is imparted to a light water coolant flowing in a pressure tube, boiling water is divided into steam and saturated water in a drum, and the steam passes through a turbine via piping and returns through a pipe to the drum. On the other hand, about 6% of power is imparted to a heavy water moderator and circulates in a loop comprising a circulation pump, a heat exchanger, and a pipe. If the flow rate of the circulating pump is made variable, the amount of voids may be controlled. (Yoshino, Y.)