As part of the nuclear deal, Iran agreed to reduce its uranium stockpile to less than 300 kg of 3.67% enriched uranium (http://www.state.gov/r/pa/prs/ps/2015/04/240170.htm , http://www.bbc.com/news/world-middle-east-33521655 , https://medium.com/the-iran-deal/joint-comprehensive-plan-of-action-5cdd9b320fd ). The IAEA must verify compliance with this aspect of the deal prior to "Implementation Day." For more information on the timeline of the agreement see: https://news.riskadvisory.net/2015/16/iran-summary-of-nuclear-deal-timeline-and-sanctions-relief/ , http://csis.org/ppp/index.htm .