28th April 2013

An update on the ITER nuclear fusion project

Design approval has been given for a crucial reactor component of the ITER nuclear fusion project, which is currently under construction in France and expected to begin generating power in 2022.

The ITER blanket system, a crucial technology on the way to fusion power, will now proceed to the manufacturing stage. "The development and validation of the final design of the ITER blanket and first wall technology is a major achievement on our way to deuterium-tritium operation — the main goal of the ITER project," said Rene Raffray, in charge of the blanket for the ITER Organisation. "We are looking at a first-of-a-kind fusion blanket which will operate in a first-of-a-kind fusion experimental reactor."

The ITER blanket system (illustrated above) provides the physical boundary for the plasma and contributes to the thermal and nuclear shielding of the vacuum vessel and the external machine components such as the superconducting magnets operating in the range of 4 Kelvin (-269°C). Directly facing the ultra-hot plasma and having to cope with large electromagnetic forces, while interacting with major systems and other components, the blanket is arguably the most critical and technically challenging component in ITER.

Due to the high heat deposition expected during plasma operation (the blanket is designed to take a maximum thermal load of 736 MW), ITER will be the first fusion device with an actively cooled blanket. The cooling water is fed to and from the shield blocks — of which there are 440, with each module weighing up to 4.5 tons — through manifolds and branch pipes. Furthermore, the modules have to provide passage for the multiple plasma diagnostic technologies, for viewing systems, and for the plasma heating systems.

The procurement of the shield blocks is equally shared between China and Korea. The first wall panels will be manufactured by Europe (50%), Russia (40%) and China (10%). Russia will, in addition, provide the flexible supports, the key pads and the electrical straps.

The assembly of the blanket system will be among the final stages of the ITER project. Completion had originally been scheduled for 2019, but delays with the construction and commissioning phases have pushed this back to 2022.

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