VIENNA Iran has markedly slowed the expansion of its uranium enrichment program, the U.N. nuclear watchdog said on Thursday in its latest report on the Islamic Republic's disputed atomic activity.
The following outlines when and how Iran could reach the threshold of manufacturing a nuclear device at short notice by virtue of its non-military nuclear assets and expertise.
DOES IRAN HAVE ENOUGH RAW MATERIAL FOR A BOMB?
The International Atomic Energy Agency report said Iran had accumulated close to 1,000 kg of low-enriched uranium (LEU). With almost 4,000 centrifuges now churning out LEU, Iran would need only a few more months to reach 1,700 kg, the amount U.N. watchdog experts regard as viable for conversion into enough high-enriched uranium for one atom bomb. Smaller quantities might also be enough, some U.S. analysts believe, but this might overestimate Iran's technical skill in weapons' building.
IS IRAN ON THE VERGE OF BOMB STATUS?
No, at least from what can be surmised. Iran would face a series of technical hurdles, though none as difficult as producing quality nuclear fuel in industrial quantities.
* reconfiguring its existing centrifuge enrichment plant at Natanz to reprocess LEU into weapons-grade HEU, or building clandestine facilities without the knowledge of U.N. inspectors
* converting HEU into metal and compressing it small enough to fit into the cone of a missile or other delivery vehicle
* designing a nuclear trigger mechanism
* mastering how to create a sustained nuclear chain reaction with an extra source of neutrons
* assembling the actual warhead
All this could take 2-5 years, depending on Iran's technical prowess, but probably much less time than the 20 years it took Iran to acquire enrichment equipment and knowledge from the nuclear black market and make it work.
ARE THERE OTHER RESTRAINING FACTORS?
Yes. It would be very hard for Iran to "weaponize" the enrichment process at Natanz without the IAEA noticing and sounding the alarm, since the plant is under regular surveillance by inspectors.
Iran has pledged to stick to enrichment for civilian energy only, under routine IAEA monitoring. It has said nuclear weapons are against its Islamic values although its record of nuclear secrecy and limiting IAEA access has raised suspicions.
Assuming Iran had a bomb agenda, which it denies, military diversions would more likely be carried out at a covert plant. That would be all but impossible for the IAEA to ferret out since Iran does not observe the agency's Additional Protocol allowing snap inspections beyond declared nuclear sites.
If Iran chose to weaponize enrichment at Natanz, it would probably kick out the IAEA and quit the Non-Proliferation Treaty, drastic steps that would almost certainly provoke Israeli or U.S. attacks to smash its nuclear facilities.
ARE ENRICHMENT AND A BOMB AGENDA THE SAME THING?
No, but it's not so simple. Iran says it will not refine uranium for anything else but electricity. Being able to enrich at industrial scale is not tantamount to seeking a nuclear weapon and is the sovereign right of NPT members as long as the work remains strictly for peaceful applications.
But the dilemma is that mastering enrichment technology provides a latent ability to build bombs at short notice. The distinction between latent capacity and weaponization can be virtually invisible in a vast country that limits the scope for U.N. non-proliferation inspections.
(Editing by Robert Woodward)