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For practical application of nuclear fusion energy technologies, scientific and technical feasibility studies are being conducted.

A torus vacuum vessel that was 10 m in diameter, 6.6 m in height, and 150 tons was divided and manufactured into ten double-walled sectors with D-shaped cross sections. Each sector was manufactured in the factory. Appropriate welding methods and their conditions were surveyed to suppress welding distortion. In addition, the manufacturing procedure, including the correction for weld distortion, was devised to reach the required product accuracy.

In the overall assembly work of the Tokamak, we designed the assembly procedure and tools for the equipment, such as vacuum vessels, superconducting coils, heat shields, and the internal parts of the reactors, and manufactured them in Japan and Europe. We have also made the on-site work plans, including surrounding works to be done simultaneously.

During the on-site welding of the vacuum vessel sector, we utilized a 3D laser measurement system and installed, welded, and connected the sectors with high precision while adjusting their positions.

The International Thermonuclear Experimental Reactor (ITER) is an effort to realize the world's first experimental nuclear fusion reactor. It aims to demonstrate nuclear fusion energy technologies for peaceful use. With the international collaboration of 7 participants, including Japan, the EU (European Union), the U.S., Russia, Korea, China, and India, ITER is being built in France. We have been participating in this project in the preparatory consideration stage and have made contributions to the concept and engineering designs. We are still contributing in the current manufacturing stage with the production of the TF coil, remote maintenance device, etc.

Designing and manufacturing the world's largest superconducting coil, "TF coils", with great precision

In the ITER project, we are involved in the design and manufacturing of TF coils (toroidal field coil). TF coils are large-scale superconducting coils and are 16.5 m in height, 9 m in width, and about 300 tons. The superconducting wire is wound into a D-shape and enclosed in the structure to support the electromagnetic force; the procedure must be done with an accuracy of millimeters.

We develop demonstration reactors with the National Institutes for Quantum and Radiological Science and Technology (QST). Based on the expertise obtained through our involvement with large-scale plasma experimental devices and ITER, we are contributing to realizing demonstration reactors with steady and stable electricity and that can produce several hundred megawatts. We endeavor to establish blanket systems with easier productivity and plant safety systems.

This is one of the largest helical-type devices in the world. We have supplied the super conducting poloidal coils, heating devices, and flywheel motor generator. (Courtesy of the National Institute for Fusion Science (NIFS)).

QUEST is a spherical Tokamak for plasma wall interaction experiments under steady-state, ultra-long pulse plasma production. We supplied the main facility. (Courtesy of Kyushu University).