STEVE INSKEEP, Host:
Here's NPR's Peter Kenyon.
PETER KENYON: Both proposals, officials say, met with Iranian insistence that no idea could be discussed so long as sanctions remain in place, and the world refuses to recognize Tehran's right to enrich uranium. But experts say that doesn't mean those ideas - and others - aren't worth discussing.
L: to create isotopes that help in medical diagnoses. Weapons-grade fuel is enriched to 90 percent.
F: the age and condition of the reactor itself.
M: It's old, and it's running out of fuel, and I think that they were a little bit worried about the safety and security because as you know, the reactor is, today, practically in the middle of the town.
KENYON: Heinonen, now at Harvard's Kennedy School of Government, says if negotiators succeed in striking a new, bigger fuel-swap deal - bigger to account for Iran's growing stockpile of enriched uranium - they would be extending the life of this aging, urban reactor by some 10 years. So, he says, why not go for a bigger and ultimately safer proposal: Build a new research reactor - possibly down at Arak, site of a still-unfinished heavy water reactor.
M: What about building a modern research reactor? Put it to Arak, to this building which is not yet fully completed. It will take two, three years at least, you know, to design and build. And then after that process, you know, they have a brand-new, good research reactor which can produce, in a safe and secure manner, radioisotopes for all Iran, without any trouble.
KENYON: Such proposals would certainly break the current stalemate, analysts say, but they raise difficult questions. Bruno Tertrais, a nuclear expert with the Paris-based Foundation for Strategic Research, says building Iran a new research reactor is a fascinating idea. But what would the international side, known as the P5+1, get in return?
M: This is where it gets interesting. On paper, the idea of proposing Iran to build for them a new reactor devoted to the production of medical isotopes is a great idea. But I would expect that the P5+1 would demand a very big concession from the Iranians in return.
KENYON: Peter Kenyon, NPR News, Istanbul.