Frazer-Nash completes ITER reactor equipment analysis

The consultancy’s engineers have improved the design of the neutral beam injectors (NBIs) — devices that heat the plasma inside the fusion reactor — so that they can withstand any forces they might encounter during ITER’s operation.

ITER will be a tokamak — a reactor that induces fusion in a hydrogen isotope plasma held inside a doughnut-shaped vessel by magnetic fields. Because the isotopes are stripped of electrons and are positively charged, they must be accelerated to high speeds to overcome electrostatic repulsion and collide, leading to fusion. One way of doing this is to inject very fast, uncharged deuterium atoms into the plasma.

The NBIs at ITER will be larger than any other tokamak’s, but have to fit into a confined space outside the reactor vessel. Because of fast temperature changes or seismic events, they could experience large stresses. Frazer-Nash analysed the design of the supporting frames for the NBIs and the adjustable steel ‘beds’ they sit on, using computational simulations to apply the worst seismic or thermal shocks they might encounter.