FUSION ENERGY : Experience and deliveries

[ Nuclear Power Generation ]

[ ENERGY ]

Experience of Fusion Reactor

The plasma vacuum vessel system provides a high vacuum environment to confine generated plasma with functions to collect charged particles composed of ions and electrons. The vessel system is designed to bear huge mechanical loads which due to electromagnetic and thermal load.

Plasma vacuum vessel
	Kyoto University, Heliotron DR Delivered in 1981 Helical magnetic field device Vacuum Vessel • Cross-section Circular shape • Major radius 0.9m • Minor radius 0.112m
	JAERI(Note1), JFT-2M Delivered in 1983 Tokamak magnetic field device Vacuum Vessel • Materials SUS304L • Upper and lower toroidal segments by press forming • Local vacuum Type EBW machine • D-shaped cross-section • Major radius 1.3m • Width/Height 0.7m/1.7m
	JAERI , JT-60U Delivered in 1991 Tokamak magnetic field device Vacuum Vessel • Materials INCONEL 625 • Double-walled structure • Multi-curvature cross-section • Major radius 3.4m • Width/Height 2.38m/3.26m
	AIST(Note2), TPE-RX Delivered in 1998 Revered Field Pinch device Vacuum Vessel • Materials SUS316L • Bellows type vacuum vessel • Circular croo-section • Major radius 1.72m • Minor radius 0.48m

• 1Japan Atomic Energy Research Institute
• 2National Institute of Advanced Industrial Science and Technology

Plasma Facing Component

Plasma facing components (PFCs) use heat and particle resistant materials to experience and resist high heat flux and particle flux exposed from plasmas, and to minimize radiation losses from the core plasmas. At JAERI experimental fusion reactor called JT-60U, The materials of PFCs had chosen high density graphite and carbon-fiber reinforced carbon composites (CFC) which have a high thermal conductivity and high melting point of material.

Plasma facing component
	Nagoya University, ALT limiter of TEXTOR Delivered in 1986 Protection structure for pumped limiter Three-dimensional shape Armor materials Isotropic graphite Base structure materials INCONEL 625
	JAERI(Note), W-shaped divertor of JT-60U Delivered in 1998 Armor materials Graphite (low heat flux region) Carbon-fiber composite (high heat flux region) Base structure materials INCONEL625

• Japan Atomic Energy Research Institute

Experience of fuel systems

Pellet injector is a equipment used to supply fusion fuels into the core plasmas by fuel pellets consisted by solid hydrogen isotopes. A pellet injector designed and manufactured by MHI installed and injected ice pellets, with accelerated speed up to 2.3km/sec, into JT-60U to utilize high temperature and highly pressurized hydrogen gas as propellant gases.

Pellet injector for JAERI
	JFT-2M Single pellet pneumatic injector Delivered in 1983 Pneumatic type Pellet species:Hydrogen Pellet sizes:1mmφ x 1mmL Propellant gas:Hydrogen gas Injection speed of pellet:0.9km/sec
	JFT-2M 4-pellet pneumatic injector Delivered in 1987 Pneumatic type Pellet species:Hydrogen/Deuterium Pellet sizes:1.28mmφ x 1.4mmL (3) 1.48mmφ x 1.6mmL (1) Propellant gas: Hydrogen gas Helium gas Injection speed of pellet:Max. 1.4km/sec
	JT-60 4-pellet pneumatic injector Delivered in 1988 (updated) Pneumatic type Pellet species:Hydrogen/Deuterium Pellet sizes:3mmφ x 3mmL 4mmφ x 4mmL Propellant gas: Hydrogen gas Injection speed of pellet:Max. 2.3 km/sec
	JT-60 Centrifugal pellet injector Delivered in 1997 Centrifugal type, Extruder Pellet species:Deuterium/(Hydrogen) Pellet sizes:2mmφ x 2mmL Injection speed of pellet:Max. 1.0 km/sec Repetition rate:10 Hz Duration time:10 sec

• Japan Atomic Energy Research Institute

Fusion energy plants use two nuclides (hydrogen isotope) to fuse nucleuses as fusion fuels which are deuterium and tritium produced from lithium. Handling of tritium is a key technologies of the fusion system design.
In a fusion energy plant, tritium is gathered from a blanket system and the exhaust gas system. Then the tritium is purified, stored, and used as fuels for the plasmas, by creating an effective closed fuel cycle for the fusion energy systems.
MHI had supplied tritium handling systems with Palladium membrane diffuser and electrolysis cells to separate nuclide from mixed gases, and ZrCo bed bottles designed to absorb and store hydrogen gases.

Tritium handling system for JAERI

TPL Air detritiation system (1985)

Fuel clean-up and Isotope separation system (1988)

Fuel clean-up system of TSTA in LANL (1990)

• Japan Atomic Energy Research Institute

Components of fuel systems

Pd membrane diffuser Operating Temperature: 300 to 450 deg. C

Ceramic Electrolytic cell Electrolysis temperature 600℃

Active metal bed (ZrCo bed) Capacity: 200L Operating temperature:20 to 450 deg. C