Fusion is the process by which all the stars in the universe shine – and it could be the answer to the mounting energy problems on Earth.
Achieving fusion is one of the most sought-after technological goals of our time because it could yield huge quantities of carbon-free energy. The pursuit of this aim gave rise to one of the most ambitious engineering endeavours, the International Thermonuclear Experimental Reactor project (ITER).
The effort involves 35 nations joining forces to prove the feasibility of fusion as a large-scale and carbon-free source of energy. As part of this project, they are building a tokamak nuclear fusion reactor in the south of France.
Plans for ITER were set in motion in 1985, and the first plasma is expected to be generated in the coming decades.
To design and build the complex, engineers rely on today’s most cutting-edge technologies, and among them is Geomagic Design X.
The first of nine sectors of the plasma chamber was positioned on supports in May 2022
The nuclear fusion reactions taking place billions of times a second at the Sun’s core generate enough energy to power the Earth many times over.
In the tremendous heat and gravity at the core of stellar bodies, hydrogen nuclei collide, fuse into heavier helium atoms and release massive amounts of energy.
There are many advantages to achieving nuclear fusion on Earth. It offers a near-limitless supply of energy with no carbon emissions and little nuclear waste.
Existing power plants rely either on fossil fuels, nuclear fission, or renewable sources like wind or water. Nuclear fission produces radioactive waste, which can be dangerous and must be stored safely – potentially for hundreds of years.
On the other hand, the waste produced by nuclear fusion is less radioactive and decays much more quickly. In addition, nuclear fusion doesn't need fossil fuels like oil or gas.
But achieving fusion is an enormous challenge. It occurs at the centre of the Sun, and scientists need to recreate those same conditions on Earth – and the forces, pressures and temperatures needed to push atoms together is astonishing.
One approach to achieving fusion involves creating plasma, a state in which gas is heated to temperatures so elevated that electrons are separated from nuclei.
The plan at the ITER complex is to confine and control the plasma inside a tokamak device, a construction that uses powerful magnetic fields in the shape of a doughnut or torus. The finished tokamak should produce 500 MW of fusion power.
Construction of the complex in France started in 2013, and assembly of the tokamak in 2020. Behind the design of the pieces that make up the tokamak’s vacuum vessel is the Spain-based company Equipos Nucleares SA (ENSA).
The finished device will weigh 23,000 tons and measure 28 meters in diameter, making it the largest ever built. The vacuum vessel, with a volume of 840 m3, must withstand the temperature reached by the plasma inside it, which is 150 million degrees Celsius.
The tokamak's plasma chamber, the torus, will be created by assembling nine sectors measuring over 11 meters. Each sector is manufactured separately and then joined together with the surrounding parts.
The different sections of the sectors should meet up perfectly, so ENSA designed made-to-measure pieces that would connect them. The company used 3D scanning to work backwards from the existing parts and designed the connecting elements around them.
3D scanning delivers perfectly fitting joints for the plasma chamber
With the help of Spain-based engineering specialist AsorCAD, ENSA scanned the parts and created the CAD files in Design X.
AsorCAD used photogrammetry and laser scanning to capture a 3D scan of the lateral edges of each sector of the torus. With the meshes of the edges, they could easily create their corresponding CAD models in Design X. The result was an exact and editable 3D design of the edges.
ENSA’s engineering department uses these geometries to create perfectly-fitting splice plates, metal plates used to fix two or more members together, and the biscuits, smaller connectors keeping two parts in place.
ENSA would design the splice plates and biscuits around the edges of each of the sectors. Once fabricated, all the sectors will be welded together.
The first of the nine sector modules required for the vessel was lifted and installed in the assembly pit in May 2022, and you can follow the progress on the tokamak on ITER's website.
If you'd like to see how easy it is to create a parametric model from a 3D scan with Geomagic Design X, request a free trial.