BWR type nuclear reactors

Purpose: To obtain super-heated steams required in a steam turbine system and improve the heat efficiency without using a drier. Constitution: A second reactor core is disposed for obtaining super-heated steams above a reactor core for obtaining saturated steams by heating water. The power from the second reactor core is controlled by flowing control material disposed from the outside of a pressure vessel to a control pipe disposed in the reactor core, and adjusting the concentration of the control material. The size of the second reactor core is about 1/10 for that of the first reactor core and the surface temperature of the fuel rod is about 350 deg C, to sufficiently ensure the integrity of the fuel can. Further, a gas-liquid separator required so far is no more necessary. (Ikeda, J.)