ICONE23-1617 RECENT PROGRESS OF JT-60SA PROJECT FOR THE PROMOTION OF FUSION RESEARCH AND DEVELOPMENT

Abstract

For the purpose of the early realization of fusion energy, construction of JT-60 Super Advanced (JT-60SA), a superconducting tokamak facility, is steadily proceeding in JAEA Naka Fusion Institute located in Naka city, Ibaraki prefecture, Japan, toward the first plasma in March 2019. This project is conducted under the Satellite Tokamak Programme of the Broader Approach Agreement and the Japanese national programme. It contributes to a wide range of fusion research and development, especially in conducting supportive researches for the ITER project to accomplish its technical targets, and conducting complementary researches to the ITER project necessary to design and construct a demonstration fusion power plant (DEMO). It also has an essential role to train domestic scientists and technicians, especially those in younger generation, who are expected to play leading roles in ITER and DEMO. JT-60SA, upgrade of JT-60U which used normal conducting coils, commands high-temperature and high-pressure deuterium plasmas in the breakeven condition for a long pulse duration (typically 100 s). It has powerful auxiliary heating and current drive tools using Neutral Beam Injection system and Electron Cyclotron Resonance Frequency system, several kinds of plasma stability control coils and flexible plasma shaping capability. JT-60SA is a powerful device for exploring and optimizing operation scenarios of ITER and DEMO. Major components of JT-60SA have been procured by EU and Japan; e.g. toroidal field coils, poloidal field coils, vacuum vessel (VV), thermal shields, power supply system, cryostat, cryogenic system and so forth. Some facilities previously used by JT-60U are reused with refurbishment and repair; e.g. central substation, motor generators, and so forth, to reduce overall construction cost. Performance of auxiliary heating and current drive facilities are also improved. Disassembly of JT-60U in the torus hall of Naka Fusion Institute was completed in October 2012. Assembly of JT-60SA started in January 2013. Cryostat base and three poloidal field coils were already installed in the tokamak hall, and seven 40-degree VV sectors as well as two 30-degree VV sectors put on the cryostat base are being welded on by one. Quench Protection Circuit, a power supply system fabricated by EU, was also delivered to Naka. On site assembly work has been set forward in a robust manner. In parallel with construction of JT-60SA, research plan of JT-60SA has been intensively discussed involving members of research communities in EU and Japan. In the eight principal research areas, research proposals from European and Japanese researchers have been elaborated and put together as "JT-60SA Research Plan", which is open to public and will be updated on a periodic basis in the future.