Before assembly of the JT-60SA tokamak could begin, the JT-60U tokamak and much of its peripherals were removed and temporarily stored in other controlled buildings or areas for reuse, or to allow radioactive afterheat decay. The JT-60U tokamak was partly re-assembled and is now on display in the JT-60 storage building, a controlled radioactive environment. Disassembly began in April 2009, and continued even after the completion of the disassembly of the tokamak device, with disassembly and re-assembly in the radioactive controlled area in compliance with related laws and regulations.

Assembly began at the start of 2013 with the installation of the cryostat base followed by the lower poloidal field coils (EF4, 5, 6) one year later. This was followed by the vacuum vessel assembly, except for one 20° segment. The toroidal field coils (TF) and their thermal shields were moved into position through this gap, and the vessel then closed and lower port sections added. The upper EF coils (EF1, 2, 3) and CS were then moved into place and the remaining port sections attached. During this phase in-vessel components were installed in parallel when possible. Auxiliary systems such as diagnostics, NBI and ECRF were respectively refurbished and assembled into place around the tokamak. The basic principles of the procedure are shown in this short animation.

Power supplies and the cryoplant were installed and connected in parallel with the assembly activity in the torus hall. Before operation can start, integrated commissioning of the tokamak is necessary with, for example, leak tests of the vacuum vessel being performed before and after baking.

A summary of the story of JT-60SA assembly , with many interesting details can be found at this link.