ITER Fusion Project Overview

Summary

ITER is the world’s largest, most powerful nuclear fusion experimental reactor, located in southern France.
Project unites 35 nations, aiming to replicate the Sun’s fusion to deliver clean, abundant energy.
ITER is an experimental facility designed to demonstrate burning plasma and inform future commercial reactors.
Construction started in 2010; major civil, mechanical, and cryogenic infrastructure largely complete, but assembly paused for repairs.
Original cost and schedule have risen significantly; new plan targets full startup around 2036 with an increased budget.

Purpose: Demonstrate controlled nuclear fusion at scale, creating self-sustaining (burning) plasma.
Technology: Tokamak design using hydrogen isotopes (tritium and deuterium), superconducting magnets, vacuum vessel, cryogenics.
Scale: Site ~180 hectares; Tokamak structure rises 60 m and extends 13 m below ground.
Participants: 35 nations; Europe provides ~45% of construction funding; Japan, China, India, Russia, Korea, USA each ~9%.

Tokamak (central device): vacuum chamber, superconducting magnets, heating systems for plasma (~150 million °C).
Superconducting magnets: 18 toroidal field coils plus six poloidal field coils; require cooling near absolute zero.
Cryogenics plant: produces liquid helium to cool ~10,000 tons of superconducting magnets.
Vacuum vessel and stainless-steel cryostat: cryostat built in 54 segments (manufactured in India), shipped and transported via an upgraded ITER roadway.
Assembly Hall: million-component assembly area with heavy cranes; all vacuum parts require leak-tight integrity.
Support buildings: power conversion, cooling towers, control rooms, waste management, high-voltage systems.

Component	Purpose	Notes
Tokamak	Contain and confine plasma	Central experiment; millions of parts; must be assembled with zero-tolerance errors
Toroidal Field Coils	Magnetic confinement	18 D-shaped superconducting coils; half manufactured in Japan
Cryogenics Plant	Cool superconductors to near absolute zero	Produces liquid helium; critical for magnet performance
Vacuum Vessel / Cryostat	Maintain vacuum and thermal shielding	Largest stainless-steel vacuum chamber; shipped in 54 segments
Assembly Hall	Component checks and pre-assembly	Heavy cranes; full-scale leak testing; specialty welding
Site Infrastructure	Utilities and logistics	39 buildings; power conversion, cooling, waste, roads (ITER itinerary upgraded)

Workforce: ~15,000 workers from ~5,000 companies; nearly 90 countries represented.
Logistics: Large components transported from global suppliers via an upgraded 100+ km special route (ITER itinerary).
Civil engineering: Specialized concrete mixes, seismic isolation bearings (~500 rubber pads), and ring fortress bioshield (3 m thick) for radiation protection.
Project management tech: Digital platforms (e.g., Procore) used for collaboration, records, and BIM to manage complexity.

Origins: International fusion initiative began in 1986; ITER officially formed with broader partners later.
Design finalized: 2001 with initial cost estimate €5 billion.
Construction began: major site works 2010; assembly and magnet fabrication continued over following decade.
Cost revisions: 2007, 2016 design reviews; 2016 cost ~€22 billion; June 2024 plan added ~€5 billion more.
Schedule changes: First plasma target moved from 2025; new approach removes low-power first plasma step and targets full startup by ~2036.
Technical issues: November 2022 discovery of cracks in cooling pipes and vacuum vessel non-conformities paused assembly; remedial action teams formed and repairs underway.

ITER goal: Achieve burning plasma and demonstrate feasibility for future commercial fusion power plants.
Complementary efforts: Other devices achieved important milestones:
- Wendelstein 7-X stellarator (Germany) achieved first plasma and maintained reaction for 8 minutes.
- National Ignition Facility (USA) achieved fusion ignition with laser implosion, producing greater output energy than input pulse in a single experiment.
Fusion methods differ (tokamak vs. stellarator vs. inertial confinement), but global community collaborates toward common fusion energy goals.

Shift in commissioning strategy: Eliminate separate low-power “first plasma” stage; pursue direct startup to full power for advanced experiments.
Repairs and quality control: Action teams created to address vacuum vessel and thermal shield defects; phased module reinstallation planned.

(Early next year – ITER) Install first corrected vacuum module back into the tokamak pit.
(Ongoing – ITER management) Complete remedial repairs on cooling pipes and vacuum vessel sectors.
(Under review – ITER stakeholders) Finalize June 2024 revised project plan, costs, and updated schedule toward 2036 startup.

What is the final agreed budget and funding commitments after the June 2024 revision?
What specific additional design or procurement changes will occur to prevent future quality issues?
How will international partners adjust contribution schedules given the extended timeline?
What lessons from other fusion milestones (NIF, Wendelstein 7-X) will be integrated into ITER commissioning?