Ayear ago, fusion scientists and engineers were celebrating the formal creation of a new global collaboration initiative – Iter – more than 20 years after it was first proposed as a way to demonstrate that nuclear fusion could be a clean and plentiful energy source for the 21st century.

Celebrations were in order. After endless delays and political wrangling over locating and paying for the reactor, it was a great relief actually to be preparing the ground for a real facility on a specific site: Cadarache in the south of France.