MELISSA BLOCK, HOST:
This is ALL THINGS CONSIDERED, from NPR News. I'm Melissa Block. In Geneva tomorrow, negotiators from six nations will sit down to talks with Iran over that country's nuclear program.
At the heart of the negotiations are Iran's centrifuges, machines that can be used to enrich uranium for use in nuclear power plants or in a nuclear bomb. As NPR's Geoff Brumfiel reports, the double role of centrifuges has negotiators in a bind.
GEOFF BRUMFIEL, BYLINE: If you want to go into the uranium business, talk to this guy.
JAY LAUGHLIN: My name is Jay Laughlin, and I enrich uranium.
BRUMFIEL: Jay Laughlin works for URENCO, a company with a huge uranium enrichment plant right here in the USA, out in New Mexico. It looks kind of like one of those boxy IKEA stores. In one end of the plant goes natural uranium; out the other comes uranium that can be used in nuclear reactors. In between are centrifuges.
LAUGHLIN: What the centrifuge basically is - is a long, thin cylinder.
BRUMFIEL: Natural uranium in the form of a gas is fed into the cylinder, which is spinning fast. How fast?
LAUGHLIN: Ah - that would be classified information. I'll tell you that it'll be much faster than you're going to ever imagine they spin.
BRUMFIEL: This spinning causes one kind of uranium, known as uranium-235, to concentrate at one end of the centrifuge. The concentrated, or enriched, uranium is fed into another centrifuge, which concentrates it a little more. And so it goes - again and again and again.
LAUGHLIN: I can't give you the exact number of centrifuges. I'll tell you it's in the thousands - or tens of thousands would be, probably, a closer estimate.
BRUMFIEL: As the concentration of uranium-235 goes up, it starts to become useful. At around 5 percent, the uranium will give you a nice, steady nuclear burn - perfect for a power plant. At 90 percent uranium-235, the fuel will ignite in a flash - it's a bomb. Jay Laughlin's plant is perfectly legal; regulators watch it carefully to make sure it never goes above that 5 percent mark.
But Iran is a different story. It started its centrifuge program in the 1980s, using designs bought off the black market. And for many years, it was completely secret.
DAVID ALBRIGHT: It looks like it was initially set up as a military program.
BRUMFIEL: David Albright is with the Institute for Science and International Security, a think tank that tracks covert nuclear programs.
Everything was kept quiet until 2002, when the international community learned Iran was building a big centrifuge plant. But here's where the story takes a twist. Iran didn't try to cover up what it had done.
ALBRIGHT: Iran did something very clever. I mean, it knew it was caught, and so it decided to try to get ahead of it, a little bit.
BRUMFIEL: Basically, they came clean and did a big mea culpa. Yeah, it looks bad, they said. But all we wanted to do was make fuel for nuclear reactors.
ALBRIGHT: They've taken a very hard line. They deny they ever thought about building nuclear weapons - ever.
BRUMFIEL: Inspectors from the International Atomic Energy Agency began visiting Iran's enrichment facility regularly. Olli Heinonen is a former inspector who now works at Harvard University.
OLLI HEINONEN: Yeah, you'd knock the door, and they normally wave you through the security.
BRUMFIEL: Inspectors like him counted centrifuges and took samples of uranium to make sure it wasn't being enriched beyond 5 percent. At the diplomatic level, things were still tense. Intelligence sources knew that parts of the program remained hidden. For example, a second enrichment plant was exposed in 2009, but Heinonen says that most of his inspections were friendly. The people he met were a lot like Jay Laughlin, who's enriching uranium in New Mexico.
HEINONEN: These are just like any other persons. They are very often young, enthusiastic engineers. They just want to do a good job.
BRUMFIEL: But their job, says David Albright, was to vastly expand Iran's enrichment capability without technically breaking the rules.
ALBRIGHT: In the last 10 years, Iran has developed its centrifuge program greatly.
BRUMFIEL: Today, Iran has thousands of centrifuges. They've enriched lots of uranium to the legal limit. But here's the trick: If Iran decides to, with very little effort it could feed that uranium back through the centrifuges and enrich it up to 90 percent.
ALBRIGHT: In a month to a month and a half, it could have enough weapon-grade uranium for a nuclear weapon.
BRUMFIEL: Not everyone agrees with Albright's estimate. And of course, when inspectors like Olli Heinonen show up at these facilities, they're told: We'd never do that.
HEINONEN: But I don't think that, you know, the guy necessarily on the facility floor knows what's the real, true intention of the program. Maybe very few people in the country know.
BRUMFIEL: This is the challenge facing negotiators. You can inspect facilities and watch centrifuges spin. But you can't know the minds of the people who run them.
Geoff Brumfiel, NPR News.
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