Kabushiki Kaisha Toshiba

Hitachi, Ltd.

Hitachi Software Engineering Company, Ltd.

Hitachi Seibu Soft Ware Co., Ltd.

Toru Yamamoto

Akira Nishimura

Toshiaki Arai

Katsumasa Haikawa

Taketoshi Sakuraba

Ritsuo Yoshioka

Kazuo Imai

Yasushi Hirano

Shunsuke Ogiya

Takeshi Seino

Nobuo Yamamoto

Michio Tandai

Masamitu Nomura

A nuclear reactor core is provided with a fuel assembly which comprises channel boxes respectively separated with spaces into which control rods are arranged and a plurality of fuel rods arranged in the channel box, at least a part of the fuel rods being charged with uranium-plutonium mixture fuel and an enrichment of U-235 or a concentration of plutonium, or both being distributed in an axial direction of the fuel rods. The concentration of a burnable poison packed in the fuel rod is distributed in the axial direction of the fuel assembly. The ratio of the occupying region of a moderator of the fuel assembly is increased with respect to the fuel occupying region. The number of the fuel rods containing the burnable poison is variously changed with respect to the total number of the fuel rods and the arranging mode thereof is also varied with the concentration thereof.

Fuel assembly of nuclear reactor

A method of controlling data which is stored into a common storage in a multiprocessor system having a common storage which can be accessed from a plurality of computers is disclosed. Particularly, a method of controlling shared data using an extended storage as a common storage is disclosed. The copy of the data of a part of or all of a shared data set in an input/output device and the copy data control information to control the copied data are stored into the common extended storage. In the case of accessing the data in the common extended storage, the mutual exclusion among a plurality of computers and the consistency control of the data are realized by referring to the control information stored in the common extended storage.

Method of controlling shared data among computers

A fuel assembly of the type having a plurality of a fuel material characterized in that a water rod disposed in a channel has a large diameter so that it has a space into which a plurality of fuel rods could be loaded and liquid water boil flows through the water rod and which has a section filled with a fuel material comprising a natural uranium section defined at least one of the upper and lower ends of each fuel rod and an enriched uranium section comprising the uppermost, intermediate and lowermost sections each having a different degree of average enrichment across a cross section of the fuel assembly and the upper and lowermost sections have the degree of enrichment across a section of the fuel assembly is lower than that of the intermediate section, and the enriched uranium section has two sections each of which has a different content of a burnable poison per unit length in the axial direction and the content of the burnable poison per unit of length in the axial direction in the uppermost section is less than that in one or more sections outside of the enriched uranium section.

Fuel assembly for nuclear reactor

Growing community of inventors

Yokohama, Japan

Toru Yamamoto