Boiling water reactor

Abstract

Abstract PURPOSE:To enable safe and stable operation with good characteristics by increasing the water to fuel ratio of mixed type fuel assemblies to the ratio larger than the water to fuel ratio of uranium fuel assemblies so that the neutron flux spectra thereof are equaled to the neutron flux spectra of the uranium fuel assemblies. CONSTITUTION:Fuel pellets 32 are laminated and packed vertically into clad pipes 31 made of zircalloy and end plugs 33, 34 are sealed by welding to upper and lower apertures. The fuel pellets 32 are formed by sintering powder of an uranium oxide after compression molding. The fuel pellet density of the mixed type fuel assemblies P is made lower than the fuel pellet density of the uranium fuel assemblies U. The water to fuel ratio of the mixed type fuel assemblies P is increased to the ratio larger than the water to fuel ratio of the uranium fuel assemblies U so that the neutron flux spectra thereof are nearly equaled to the neutron flux spectra of the uranium fuel assemblies U. The good characteristics equiv. to the characteristics of the reactor core using only the uranium fuel assemblies are thus obtd. and the safe and stable operation is enabled.

Inventors

• 👤 Shinji Hattori
• 👤 Tetsuo Takeshita

Bibliographic Details