Kabushiki Kaisha Toshiba

Shouichi Watanabe

Makoto Ueda

Akira Tanabe

Hisao Suzuki

Mamoru Nagano

Ritsuo Yoshioka

Kouji Hiraiwa

Koichi Sakurada

Shunsuke Ogiya

A core of a light-water reactor comprises a plurality of fuel assemblies each including a number of fuel rods. The fuel rod is provided with at least one area interposed between fuel areas in a clad of the fuel rod. The interposed area contains extremely reduced or substantially no fissile nuclide. At least two areas or layers with high enrichment of the fissile nuclide are formed in the axial direction of the reactor by the location of the interposed areas throughout the whole fuel assemblies arranged in the light-water reactor core.

Core of light-water reactor

A fuel assembly for a nuclear reactor includes a number of fuel rods filled with a fuel material. A water rod having a cross sectional area larger than that of each fuel rod is disposed at substantially the central portion of the fuel assembly. The fuel rods include first fuel rods having a whole effective fuel zone filled with a fuel material throughout the entire length thereof and second fuel rods each having an interposed zone in which enrichment of a fissile nuclide is significantly reduced or the fissile nuclide does not exist at all. The second fuel rods are arranged so as to surround the water rod so that the interposed zones are positioned on an axial level including a portion at which subcriticality is made small at a period in which maintenance of reactor shut-down margine is made difficult during the reactor operation period. The water rod may be provided with a lower portion having a cross sectional area smaller than that of an upper portion and short fuel rods are disposed so as to surround the lower portion of the water rod.

Fuel assembly for nuclear reactor

Growing community of inventors

Ibaraki, Japan

Shouichi Watanabe