Mitsubishi Heavy Industries Limited

Kazuo Murakami

Yasuhiro Sakaguchi

Kenichi Matsunaga

Toyoaki Yasui

Ganji Abe

Takashi Shige

Toshiro Kobayashi

Koichi Ue

Etsuryo Kita

Shizuo Inoue

Tomikane Saida

Tsuneo Mandai

Katsunari Ohsono

Tadashi Shiraishi

Tatsumi Takahashi

Kazuo Asada

Naoki Tokizane

Kazuhisa Shibue

Kazumi Ogura

Shigemitsu Suzuki

Kyohichi Yoshigai

Shigeru Kunishima

Shinichi Shiraishi

Kiyoshi Izumi

A basket has a lattice-like section for accommodating individual used nuclear fuel in predetermined positions in a cask. The basket is made from aluminum composite material having good neutron absorption ability, excellent mechanical property and workability. The aluminum composite material is made by having, in an Al or Al alloy base phase, B or B compound with a neutron absorption ability and an additive element, e.g. Zr or Ti, for giving a high strength property, and subjecting to a sintering under pressure.

Aluminum composite material, manufacturing method therefor, and basket and cask using the same

A primary lid is set in a top opening of a vessel body that contains radioactive substance, and closes the top opening. The peripheral edge portion of the primary lid is welded to the inner peripheral surface of the vessel body. As the primary lid is welded, steam in the vessel body is discharged to the outside through a discharge hole in the primary lid, and a shield gas is filled into or run through a space in the outer peripheral portion of the primary lid, so as to prevent the steam from flowing into the welding portion.

Closed vessel for radioactive substance, seal-welding method for closed vessel, and exhaust system used for seal-welding method

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

Aluminum powder, neutron absorber, and third particle composed of oxide, nitride, carbide or boride are mixed, and preformed by cold isostatic pressing (CIP). Successively, by canning the preformed material, this preformed material is sintered by hot isostatic pressing (HIP). After sintering, the can outside and end face are machined by grinding, and the billet is taken out. Square pipes are formed by extruding this billet.

Aluminum composite material, aluminum composite powder and its manufacturing method

A control rod for a nuclear reactor has a structure which is capable of suppressing expansion of a reduced-diameter portion of a neutron absorber in a radial direction under shocks applied upon every stepwise driving of a control rod cluster and which can ensure integrity of a cladding tube over an extended period. The control rod includes a cladding tube closed hermetically at both ends thereof by a top end plug and a bottom end plug, respectively, a neutron absorber loaded into the cladding tube and includes a reduced-diameter portion having a smaller diameter than the other portion, the reduced-diameter portion being disposed at the bottom end plug side of the control rod, and a hold-down spring for pressing the neutron absorber downwardly against the bottom end plug. A sleeve is disposed within an annular space defined between an outer peripheral surface of the reduced-diameter portion and an inner peripheral surface of the cladding tube.

Control rod for nuclear reactor

A rectangular pipe is molded by mixing aluminum powder with powder of a neutron absorbing material, molding a premolded body by means of cold isostatic pressing (CIP), canning the premolded body, sintering the premolded body by means of hot isostatic pressing (HIP), performing outer cutting and end face cutting on the can after the sintering, taking a billet out of the can, and extruding this billet.

Manufacturing method for spent fuel storage member and mixed power

The present invention provides an aluminum composite material having neutron absorbing power that improves the ability to absorb neutrons by increasing the content of B, while also being superior to materials of the prior art in terms of mechanical properties and workability. The aluminum composite material having neutron absorbing power contains in Al or an Al alloy matrix phase B or a B compound having neutron absorbing power in an amount such that the proportion of B is 1.5% by weight or more to 9% by weight or less, and the aluminum composite material has been pressure sintered.

Aluminum composite material having neutron-absorbing ability

A container body of a concrete cask includes a storage portion that stores a canister. A refilling system includes a reduction cylinder having an outside diameter smaller than the diameter of the storage portion and an inside diameter larger than the diameter of the canister, a first lift mechanism configured to raise and lower the reduction cylinder between a down position in the storage portion and an up position wherein it is drawn out of the storage portion, and a second lift mechanism having a holding portion for holding one end portion of the canister and configured to raise and lower the canister with respect to the container body. In refilling operations, the canister is loaded into and unloaded from the storage portion of the container body by the second lift mechanism with the reduction cylinder set in the storage portion.

Storage container, storage container refilling system, and refilling method

An upper hold-down spring structure for a nuclear reactor fuel assembly. A hold down spring 20 mounted on an upper surface of an upper nozzle 11 of a fuel assembly for a pressurized water reactor is composed of an upper plate spring 21 having plastic spring characteristics and a lower plate spring 23, base ends of which are fixed with a fastening bolt 18 at a common position. The upper spring 21 and the lower spring 23 are made of precipitation hardened nickel base alloy and the thickness of the springs are determined so as to keep the stresses generated less sensitive to stress corrosion cracking.

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Hyogo, Japan

Kazuo Murakami