Mitsubishi Nuclear Fuel Co., Ltd.

Mitsubishi Heavy Industries Limited

Nuclear Development Corporation

Kimio Nakayama

Masaji Mori

Yasunao Yamaguchi

Juntaro Shimizu

Kazuki Monaka

Takashi Shimomura

Toshiya Kido

Toshifumi Naito

One object of the present invention is to provide a production method for a nuclear fuel assembly support grid that improves the corrosion resistance of welded parts without impairing the characteristics of the support grid so as to be able adequately withstand highly efficient operation. In order to achieve the object, the present invention provide a production method for a nuclear fuel assembly support grid comprising the steps of: assembling a plurality of straps in a grid form; welding intersections of each strap; and carrying out annealing thereafter to precipitate an intermetallic compound on the welded parts.

Production method for a nuclear fuel assembly support grid and a nuclear fuel assembly support grid produced by the same

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 supporting grid welding apparatus including a welding chamber configured to encase a supporting grid, at least one laser device disposed outside of the welding chamber, and a drive device configured to move the welding chamber independently from said supporting grid.

Supporting grid welding apparatus

Welding operations on a grid support housed in a welding chamber is carried out using a laser welding apparatus placed outside the welding chamber. In the interior space of the chamber, a pair of supply nozzles 44 are disposed on each of the mutually orthogonal edge sections of two top and bottom glass surfaces of the roughly cubic chamber An inert gas is ejected in a planar stream from the blast slot openings provided on each supply nozzle along the top and bottom glass surfaces and side glass surfaces. The glass surfaces that face many welding sections of the grid support are shielded by the sweeping action in two directions, and the glass surfaces that oppose lesser number of welding sections are shielded by the sweeping action in one direction with the inert gas. Fumes and plasmas produced from welding sections are thus swept away before they can reach the glass surfaces, and are discharged with the spent inert gas.

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Naka-gun, Japan

Kimio Nakayama