Mitsubishi Heavy Industries, Ltd. World Wide Web | MHI completes final coil of ITER TF –

The final TF coil unit is complete

Tokyo, 2023 August 24 Mitsubishi Heavy Industries, Ltd. (MHI) has completed production of the final toroidal field (TF) coil commissioned by Japan’s National Institute of Quantum and Radiological Science and Technology (QST) for experimental synthesis at ITER. reactor currently under construction at Saint-Paul-lès-Durance in southern France. Japan is responsible for manufacturing nine of the 19 ITER TF coils, of which MHI produced five coils.

The TF coils for ITER are huge superconducting coils, 16.5 meters high and 9 meters wide, each weighing a total of 300 tons, and to start the fusion reaction in the reactor, the manufacturing accuracy must be 0.01%. in 2020 month of January. MHI has completed the world’s first TF coil for ITER, bringing together years of extensive knowledge of mass production technologies for products with high production difficulty. The four already completed TF coils were successively transported from the port of Kobe to the south of France and installed at the construction site. This latest device is scheduled to ship from Kobe this month.

In addition to the TF coils, MHI also designs and manufactures other key components, including the divertor (Note 1) and the equatorial EC launcher (Note 2). MHI will continue to contribute to the realization of fusion energy by actively supporting the design and development of prototype fusion reactors planned for the ITER project.

  • 1The divertor is a device designed to remove impurities in the core plasma as well as suppress high heat load and particle load.
  • 2An equatorial EC launcher is a device designed to inject high-frequency electromagnetic waves to heat the plasma.
Delivery of the final TF coil

Delivery of the final TF coil

    Installation at the reactor site (© ITER Organization)

Installation at the reactor site (© ITER Organization)

Reference material

Project background

TF reel

The ITER project is an international megaproject aimed at scientifically and technologically demonstrating the realization of nuclear fusion energy (Note 3). Seven countries are involved (Japan, EU, USA, Russia, South Korea, China and India) and ITER is being built in Saint-Paul-lès-Durance, France. Japan plays an important role in the design and manufacture of key components of ITER, including the TF coils. QST, as ITER Japan’s local ITER project agency appointed by the Japanese government, oversees the procurement of these components.

ITER’s superconducting TF coils are D-shaped, about 16.5 m high, 9 m wide, and weigh about 300 tons. Eighteen TF coils will surround the vacuum vessel container and generate a powerful magnetic field (maximum 12 tesla) to confine the high-temperature, high-density plasma within the vessel. The ITER project requires a total of 19 TF coils (including one spare). Nine are made in Japan (including spares) and 10 in Europe. The internal coil structures for all 19 TF coils will be manufactured at MHI’s Futami facility. Mitsubishi Electric Corporation manufactures the niobium-tin (Nb3Sn) superconducting winding packages for the five TF coils made in Japan (including spares), while the outer coil structures are manufactured in South Korea and finally assembled at the Futami plant.

The significance of this latest achievement

TF reel

Confining the plasma inside ITER requires a very precise, strong magnetic field (12 teslas), requiring the development of unprecedentedly large superconducting coils using niobium-tin conductors. In order to maintain superconductivity, the coils must operate at cryogenic temperatures of minus 269°C, requiring the development of special stainless steel structural materials capable of withstanding such low temperatures, along with all the necessary manufacturing techniques. Not only was there no precedent for coils of this unparalleled scale, but the dimensional tolerances of the windings and coils required a high precision of 0.01%.

QST started research and development of TF coil manufacturing technology in 2005, and MHI started production in 2012. In collaboration, QST and MHI have developed extremely precise niobium-tin conductor winding technology, as well as durable structural materials made of special stainless steel. steel that can withstand cryogenic temperatures. In addition, parametric tests were conducted to identify manufacturing methods for welding-induced deformation suppression, and welds were tested using miniature and full-scale specimens, which formed the basis for key technologies tailored to material properties, including advanced welding procedures. and machining technician. Finally, MHI was able to meet the stringent requirements of ITER.

  • 3Fusion is the source of energy that allows the sun to continue to shine, and the ultimate goal is to achieve fusion on Earth. Fusion reactions fuse light atomic nuclei (deuterium and tritium) in a plasma environment into the heavier element helium. The fusion reaction emits zero carbon dioxide, and their fuel source can be extracted from seawater in practically unlimited quantities (lithium, from which tritium is obtained, and deuterium). Fusion energy is expected to solve many of the world’s energy and environmental problems.

Godfrey Kemp

"Bacon fanatic. Social media enthusiast. Music practitioner. Internet scholar. Incurable travel advocate. Wannabe web junkie. Coffeeaholic. Alcohol fanatic."