Iran will install three cascades of advanced IR-2m centrifuges in an underground Fuel Enrichment Plant (FEP) at Natanz, according to the International Atomic Energy Agency (IAEA). Iran has already moved one cascade of 174 IR-2m centrifuges to this facility and is using that cascade to enrich uranium alongside the 5,060 IR-1 centrifuges that have been enriching uranium at the plant for years. Under the Joint Comprehensive Plan of Action (JCPOA), Iran is supposed to use only the less efficient IR-1 centrifuge for the production of enriched uranium.