Here's a render of the completed reactor: https://www.iter.org/doc/all/content/com/gallery/media/7%20-... Note human for size.

It's all completely bespoke scientific equipment hand made for this project only. The cryostat will be the largest stainless steel vacuum vessel ever made-- all welded by hand.

After welding, a substantial number of in-vessel components have to be installed by threading them through access ports, which is also quite a task: https://www.youtube.com/watch?v=pt70mO2nQac