The Isfahan Nuclear Technology Centre, located south-east of the city of Isfahan, is Iran's largest nuclear research complex. It also houses a uranium conversion facility where natural uranium is converted into material that could be enriched in the country's two uranium enrichment facilities in Natanz and Fordo.

The UN's nuclear watchdog, the International Atomic Energy Agency (IAEA), had accused Iran of enriching up to 400kg of uranium to 60 percent – not far below the 90 percent enrichment that is needed to make weapons.