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This week, Iran is set to start scaling back its nuclear program. Under the terms of an international agreement, they will cut their uranium stockpile and restrict equipment to peaceful use. And watching over all of this activity will be nuclear inspectors. NPR's Geoff Brumfiel recently got a rare opportunity to meet some inspectors and learn how they do their job.
GEOFF BRUMFIEL, BYLINE: OK, this is going to sound a little weird, but I met the people charged with making sure Iran doesn't get a nuclear weapon and a nuclear weapons lab - not in Iran, but here in America.
NANCY JO NICHOLAS: We like to say it takes a weapons lab to find a weapons lab.
BRUMFIEL: Nancy Jo Nicholas oversees global security at Los Alamos National Laboratory in New Mexico. Los Alamos built America's first nukes, and it's a special kind of place.
NICHOLAS: We used wear buttons that said, it's plutonium, stupid. That's why people come here. We have expertise in plutonium.
BRUMFIEL: Plutonium and uranium exist in ordinary nuclear power reactors around the world. But when they are properly purified and enriched, they can be used to make nuclear weapons. Under this deal, Iran has pledged to keep its nuclear program peaceful, and to prove it, the nation will be put under the watchful eye of the International Atomic Energy Agency. The IAEA's nuclear inspectors will crisscross the country, visiting labs, reactors, even uranium mines.
The goal will be to make sure that everything is accounted for, that nothing is being siphoned off into a secret weapons program. Past security checkpoints and barbed wire fences at Los Alamos, I arrive at a small building known only as TA 66. And here are the inspectors. They're in from Vienna, Austria for a two-week course on plutonium. They're learning everything about it, both the civilian kind and the kind used in nuclear weapons. Peter Santi is leading this training.
PETER SANTI: We split them up into small groups of two students plus one instructor to really make sure they get as much information as possible.
BRUMFIEL: Now, at this point, I should say it's extremely unusual for a journalist to be around active nuclear inspectors or weapons grade plutonium, for that matter. And so there are ground rules for my visit. I'm told these eight inspectors come from several different countries, but I don't know which ones. I can't ask their names. Santi says I can't even talk to them directly.
SANTI: What I can do for you is demonstrate how we do a measurement.
BRUMFIEL: Yeah. Yeah, let's do it.
BRUMFIEL: We walk across the classroom and pick up some plutonium - well, Santi picks it up. Rule No. 2 - no touching the plutonium.
This looks kind of - what? - like a paint can with a big radioactive marker on the side and a bunch of - what? - is that duct tape you're using to hold it?
SANTI: (Laughter) For convenience, we've put on some handles, essentially, using tape to make sure we can hold them. It's ease-of-use and ergonomically sensible.
BRUMFIEL: Plus you really don't want to drop the plutonium.
SANTI: Well, it makes a loud noise. And it scares everybody when it happens.
BRUMFIEL: All joking aside, just a few pounds of the stuff can be made into a powerful nuclear bomb, which is why the inspectors need to recognize it, even if it's hidden or mislabeled. We put the can of plutonium into another container about the size of an oil drum. It's designed to catch radioactive particles flying out as the plutonium decays.
SANTI: Nuclear material, when it decays, produces very unique signatures. So that's kind of a unique fingerprint to the nuclear material. And it's always being emitted by these materials because they are unstable.
BRUMFIEL: Inspectors use the radioactive fingerprint in two ways. First, they check to verify the kind of material, and then they measure it to figure out how much material is there. When it comes to something like plutonium, the numbers matter a lot.
So just out of curiosity, I mean, what would happen if we found out right now that there were only 500 grams of plutonium in that container when we thought there were 600?
Are you getting nervous there?
SANTI: It would be a huge problem.
BRUMFIEL: You would have to do a lot of paperwork, wouldn't you?
SANTI: It wouldn't be paperwork, it would be - yeah - next question.
BRUMFIEL: Fortunately, in this case, the plutonium is accounted for to within just a fraction of a percentage.
SANTI: The calculated declared plutonium mass for today is 606 grams, and we measured 607 grams.
BRUMFIEL: Inspectors will be bringing this kind of precision to work in Iran, though, there they will usually be measuring uranium. But it's not just Iran. David Lacey is a training officer with the IAEA and a former inspector himself.
DAVID LACEY: We are inspecting all different types of facilities all over the world.
BRUMFIEL: The IAEA visits civilian reactors, fuel plants and plutonium-handling facilities everywhere from Brazil to Japan to the U.S. They go in, make measurements, like the ones they're doing today, and then compare it to the official inventory to make sure it's all there. It's a challenging job even at the best of times.
LACEY: You know, an inspector has to be a little bit of everything. You need to be an accountant, a little bit scientist, a little bit of diplomat.
BRUMFIEL: And to keep them on top of their game, inspectors receive continuous training in courses like this. Speaking of which, it's final exam day.
SANTI: Morning. How are you doing?
BRUMFIEL: I'm well. How are you?
Peter Santi leads me back into TA 66. The inspectors have been given a nuclear inventory from a fictional facility. Their job is to verify 12 unmarked items to see how much plutonium is inside each one. But just like what can happen in the real world, not all is what it seems.
UNIDENTIFIED MAN: There is something else. There is a lot of background from something else.
SANTI: We have made some of the items quite challenging, as well as several of the items we've lost the declaration for. So they're completely unknown to the inspectors.
BRUMFIEL: And have you done anything really naughty?
BRUMFIEL: Santi won't tell me what tricks he's using to try and fool inspectors. But whatever it is, they'll have to figure it out. And the IAEA's trainer, David Lacey, is confident they will.
LACEY: They'll be fine. They'll be fine. They get a good - they've had good teaching over the last two weeks. And I can see now, looking around, that they're perfectly capable.
BRUMFIEL: The inspections in Iran will be some of the most ambitious ever attempted by the world's nuclear watchdog. I don't know if the inspectors on this particular course are involved, and I can't ask. But what is clear is that the IAEA wants to be sure all of its inspectors are ready. Geoff Brumfiel, NPR News.
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