Iran and six world powers can reach a comprehensive nuclear deal by agreeing on Iran’s practical needs for enrichment, which are limited in the near term; as well as on technical modifications that could be made to the Arak reactor and turning the Fordo enrichment site into a research and development facility, former US nuclear negotiator Robert Einhorn writes in a paper to be released by the Brookings Institution Monday.

“I think of the big issues, Arak is the easiest,” Einhorn told Al-Monitor in an interview last week. "Fordo is hard. But the hardest single issue is enrichment capacity."

Einhorn, in his Brookings paper, “Preventing a Nuclear Armed-Iran: Requirements for a Comprehensive Iran Nuclear Deal," released to Al-Monitor in advance, proposes that Iran and the P5+1 define the practical needs for Iran’s civil nuclear program. “Indeed, Iran’s actual need to produce enriched uranium for fueling reactors is quite limited, at least in the near and middle terms,” he writes. "Proposed modifications to Arak [would make it] better for producing medical isotopes," he said.

Since reaching a breakthrough interim nuclear deal last November, Iran and six world powers have held two rounds of talks to try to negotiate a comprehensive nuclear deal by the July 20th expiration of the six month Joint Plan of Action.