Completion of disassembly of large fusion experimental device JT-60

Ikeda, Yoshitaka; Okano, Fuminori; Hanada, Masaya; Sakasai, Akira; JT-60 Team; Watanabe, Takashi*; Daigo, Yasuhiko*; Hosogane, Nobuyuki*; Aoto, Mitsuo*

Break-even Plasma Test Facilities (JT-60) is the only tokamak device applied by the Radiation Hazard Prevention Act, and is under upgrading towards the super-conducting magnetic device "JT-60SA" aiming long pulse and high beta plasmas. The JT-60SA project is in progress as the satellite Tokamak project under the Japan-EU international program "ITER Broader Approach". At the first step towards JT-60SA, the disassembly of JT-60 tokamak and its affiliated facilities was done for three years and completed in October 2012. All disassembly and cutting works were in control of radiation management. Total number and weight of disassembly components were about 13000 and about 5400 tons, respectively. The JT-60 was composed of a lot of high mechanical strength materials such as high manganese steel which is difficult-to-machine material. New technologies such as a diamond wire-saw which cut the complicated structure simultaneously enabled the effective disassembly.