Mitsubishi Heavy Industries Limited

Katsunari Ohsono

Toshihiro Matsuoka

Shinji Ookame

Yoshiharu Taura

Shigenori Shirogane

Takeshi Tsunezumi

Yoshihiko Funakoshi

Naohiro Mizuno

Katsuhiko Tokuno

Chikayuki Matsumoto

Suguru Hode

Yasuhiro Sakaguchi

Kiichiro Sakashita

Tadashi Kimura

Toyoaki Yasui

Kazuo Murakami

Masaharu Minami

Takeshi Yokoyama

Toshiro Kobayashi

Kenji Najima

Nobuo Ishihara

Kazuo Asada

Kiyoshi Ono

Makio Atsumi

Tomohiro Itoh

Shinji Ohkame

Masaru Ohsaki

In the metal billet to be used for hot dilation forming, a forward side with respect to the pressing direction has a quadrate section and its diagonal length is not more than an inner diameter of a container. Moreover, a backward side with respect to the pressing direction has a circular section and its diameter is substantially same as the inner diameter of the container. The metal billet is heated to a temperature suitable for press working and is set into a container for press forming. While a center of a workpiece of the metal billet is being bored by a boring punch to be operated by a pressing machine, the metal billet is hot-dilated so that a bottomed container for a cask is formed.

Radioactive substance container, manufacturing apparatus thereof and manufacturing method thereof

Radioactive substance containment vessel, and radioactive substance containment vessel producing device and producing method

A radioactive-material container includes a container body that shields nuclear radiation, which includes a cavity that stores a basket containing a recycle fuel assembly, a lid that covers the cavity, and a metal gasket that includes a sealing area that makes a physical contact with the container body and the lid. The sealing area has a specific shape that disperses tightening stress acting on the metal gasket for a sealing.

Radioactive-material container, metal gasket for sealing the radioactive-material container, and method of manufacturing the metal gasket

A cask includes a trunk body that includes a basket having a square pipe or a plate member forming a cell that contains a spent fuel assembly, and a neutron shield that is formed by filling a composition for neutron shielding between the trunk body and an outer cover surrounding the trunk body. The composition includes a refractory material, a density increasing agent, and a neutron shielding material composed mainly of a polymer.

Cask, composition for neutron shielding body, and method of manufacturing the neutron shielding body

Corner of each square pipe is molded into a terrace shape having steps. When a basket is constructed by these square pipes, steps of adjoining square pipes are assembled together face to face. Fuel rod aggregates are housed inside the square pipes and in a cells formed between the square pipes. Since the adjoining square pipes are assembled in a staggered arrangement, boundaries of the cells are defined by the walls of the square pipes itself.

Spent fuel housing square pipe, basket and spent fuel housing container

Heat conductive fins () are welded along both sides of a belt-like member () with a margin left along edges of the both sides, thereby to form a unit (). The unit () is welded to a body () with the heat conductive fins () from the outside of each fin. Next, another belt-like member () is covered over a gap between adjacent belt-like members (), and these members are welded from the outside. With this arrangement, there is no need to weld in a narrow and long space and the entire welding step is carried out from the outside, which makes it easier to assemble a cask.

Cask and method of manufacturing the cask

An aluminum powder is mixed with a neutron absorber powder through cold isostatic press to form a preliminary molding. The preliminary molding is then subjected to sintering under no pressure in vacuum. After sintering, a billet is subjected to induction heating and hot extrusion to form a square pipe.

Method of manufacturing a radioactive-substance storage member, billet for use in extrusion of the same, and square pipe

In the cask, a shape within a cavity of a barrel main body is formed in a shape corresponding to an outer shape of a basket. The basket has a structure obtained by alternately piling up plate-like members vertically. A heat conducting plate is provided on an outer periphery of the plate-like member. Accordingly, since the basket and the cavity are in a state of being in contact state in a wide area, an efficiency of heat conduction is improved.

Cask

The absorbing rods have a nearly the same shape as the shape of columnar control rods for PWR used in reactivity control of core in a reactor. The absorbing rods can shield neutrons, and are inserted in control rod guide pipes and measuring pipes in fuel assemblies.

Absorbing rod, an apparatus for inserting the absorbing rod, a cask, and a method of storing spent fuel assemblies

Heat conductive fins are welded along both sides of a belt-like member with a margin left along edges of the both sides, thereby to form a unit. The unit is welded to a body with the heat conductive fins from the outside of each fin. Next, another belt-like member is covered over a gap between adjacent belt-like members, and these members are welded from the outside. With this arrangement, there is no need to weld in a narrow and long space and the entire welding step is carried out from the outside, which makes it easier to assemble a cask.

Cask and production method for cask

A lightweight cask comprises a barrel body which shields gamma rays. A resin which shields neutrons is provided on the periphery of the barrel body. A basket is made of a plurality of square pipes having neutron absorbing ability. There is a cavity inside the barrel body. This cavity is worked to have a shape corresponding to the outer shape of the basket. The square pipes are inserted in this cavity so as to abut against this inner surface. Furthermore, chamfered portions are provided on the outside surface of the barrel body at 90&deg; intervals and space portions are formed between another resin and an outer casing.

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Hyogo, Japan

Katsunari Ohsono