Mitsubishi Heavy Industries Limited

Mitsubishi Nuclear Fuel Co., Ltd.

Kazuki Monaka

Juntaro Shimizu

Yoichiro Yamaguchi

Masaji Mori

Kimio Nakayama

Takashi Shimomura

Toshifumi Naito

A method of surface-treating a reactor member for effectively removing a Cr-deficient layer and a work-hardened layer considered to be a cause of stress corrosion cracking (SCC) under low-stress conditions. The method of surface-treating a reactor member which is worked by bending (step) and then processed by a heat treatment (step), in which a work-hardened layer is formed by the bending, and in which a Cr-deficient layer is formed due to an oxide film attached by the heat treatment, uses at least one of: acid wash; grinding; electrolytic polishing; electro-discharge machining; surface cutting; surface deoxidation and softening; wet blasting; laser machining; or surface plating (step) to remove the work-hardened layer and the Cr-deficient layer from the reactor member or to prevent contact of the work-hardened layer and the Cr-deficient layer of the reactor member with a primary coolant.

Method of manufacturing reactor member by using the surface treatment method

A foreign matter filter provided between a DFBN and a lower grid has two adjacent thin straps assembled into a lattice. The straps are equipped on the front and back sides with axially continuous protrusions.

Foreign matter filter for fuel assembly in pressurized water reactor

A method of surface-treating a reactor member for effectively removing a Cr-deficient layer and a work-hardened layer considered to be a cause of stress-corrosion cracking (SCC) under low-stress conditions. The method of surface-treating a reactor member which is worked by bending (step) and then processed by a heat treatment (step), in which a work-hardened layer is formed by the bending, and in which a Cr-deficient layer is formed due to an oxide film attached by the heat treatment, uses at least one of: acid wash; grinding; electrolytic polishing; electro-discharge machining; surface cutting; surface deoxidation and softening; wet blasting; laser machining; or surface plating (step) to remove the work-hardened layer and the Cr-deficient layer from the reactor member or to prevent contact of the work-hardened layer and the Cr-deficient layer of the reactor member with a primary coolant.

Method of surface-treating reactor member and method of manufacturing reactor member by using the surface treatment method

Growing community of inventors

Hyogo-ken, Japan

Kazuki Monaka