26-08-2020 | Posted by Joaquín Martí
There is an old joke among physicists that fusion energy is 20 years away… and it will always be. Admittedly, it is a joke, but it has remained true and unchanged for the last 60 years. Jokes apart, ITER (“the way” in Latin) is a tremendous project to try to advance along the route to harness fusion energy.
Next to the Cadarache facility in southern France, 35 nations are collaborating to build the world’s largest tokamak, a magnetic fusion device that has been designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy based on the same process that powers the Sun.
The basic principle is simple enough: fuse an atom of deuterium with one of tritium, and out comes a helium atom… and 17.59 MeV of energy.
The devil is in the details: to overcome the Coulomb barrier and achieve that fusion, the atoms must be packed at a sufficiently high density and temperature for a sufficiently long time. This is neither simple nor energetically cheap, and of course we would like to get from the process more energy than we put in. The ITER tokamak is designed to yield 10 times the energy input, a ratio expressed as Q = 10.
It would indeed be fantastic to have a carbon-free source of energy, based on ingredients of which there is a limitless supply. The participating nations considered the outcome sufficiently promising to enter decades of development and invest some 20 billion euros.
As could be expected in a project of that size, a considerable number of companies and organisations are involved. Starting in 2015, Principia has participated in various projects for ITER primarily in the areas of numerical modelling and earthquake engineering. For example, Principia drafted the Guidelines for Seismic Design, Analysis and Qualification of Complex Industrial and Nuclear Facilities against Seismic Hazard, accounting for nuclear safety (design or beyond-design cases), French construction requirements, and investment protection policy.
We also reviewed the evaluation of a number of critical components and, when necessary, conducted independent verification analyses, all in the light of the Guidelines. The main activities in this context dealt with the gas helium tanks, the cradles of the cold box, the foundation design basis of Area 53, the Gan buffer tanks of the cryogenic plant, the armoured port cell doors of the tokamak building, the electron cyclotron power supply (ECPS) equipment, and the optimisation of different cable tray supports for the tokamak.
Principia has also reviewed the design and calculation documents issued by contractors and participated in the CASH international benchmark to evaluate the strength of reinforced concrete shear walls subjected to earthquakes beyond the design basis. And, very recently, we carried out the seismic qualification, based on the SL-1 earthquake, of cubicles housing high-reliability electronics at ITER.
We are proud to collaborate in this gargantuan effort to provide mankind with a clean and durable energy source. Let us just hope that, 20 years from now, its fulfilment will not remain 20 years away.
