Iran has one research reactor. The plans announced by Davani would provide more than four times its annual fuel requirements. Yet this reactor is already capable of producing enough radioisotopes for up to 1m medical investigations per year – already comparable to the UK and much more than Iran needs. The plan would also require diverting at least half of Iran’s current annual output of 3.5% enriched uranium, and so deny it to Iran’s nuclear power stations. If Iran is serious about developing civil nuclear energy, why divert limited materials and resources away from the civil energy programme in this way, while spurning offers of technological assistance for Iran’s peaceful use of nuclear energy from the outside world, including the E3+3 countries of the UK, China, France, Germany, Russia and the US?

Yet there is one clear purpose for this enriched uranium. Enrichment from natural uranium to 20% is the most time consuming and resource-intensive step in making the highly enriched uranium required for a nuclear weapon. And when enough 20% enriched uranium is accumulated at the underground facility at Qom, it would take only two or three months of additional work to convert this into weapons grade material. There would remain technical challenges to actually producing a bomb, but Iran would be a significant step closer.