According to Iranian Student's News Agency (INSA) Iran's president Mahmoud Ahmadinejad is scheduled to visit the Natanz uranium enrichment facilities to see the progress of the centrifuges and technological developments and then to inaugurate the Fuel Manufacturing Plant (FMP) during his 55th provincial tour in Isfahan today (which is the 4th anniversary of its national day of nuclear technology).

Below is an overhead photo of the Natanz plant site:

Apparently, the FMP is to produce nuclear fuel plates, rods and assemblies for Iran's Arak 40-megawatt research reactor which is to be launched within the next few years.

Below is an overhead photo of the Isfahan complex:

Isfahan's FMP apparently has different production lines for different reactors thus it also has the capacity to shift activities to produce nuclear fuel assemblies for Bushehr (1000 MW Capacity) and Darkhovin (360 MW Capacity).

Okay - today on CNN Admiral Mike Mullen (Chairman of the Joint Chiefs) stated that Iran has enough material to make a nuclear weapon.

Admiral Mike Mullen, Chairman Joint Chiefs of Staff

Let's take a quick look at the statement - while it is very likely true - it is also very misleading.

There are a number of different types of nuclear weapons - but when we are talking about states trying to get the Bomb - we are generally speaking about weapons made from high enriched uranium (Uranium enriched in its U235 content to over at least 80%).

Now, according to the IAEA, Iran has managed to enrich about 1000KGs of UF6 (uranium hexafluoride) to the low-enriched state of less than 5% U235 (the enrichment level that is used in commercial power production). So - what this technically means is that Iran has enough Low Enriched Uranium (LEU) that if they could get the technology working right - and given sufficient time, they could eventually take that LEU and probably produce a sufficient quantity of HEU (High Enriched Uranium) from it. What this doesn't mean is that they actually have high enriched uranium on hand for a bomb.

A quick bit about Uranium. Uranium is mined all over the world. In its natural state, it is primarily made up of U238 (roughly 99.284%) and U235 (roughly 0.711%) - with U235 being the fissile isotope.

Nuclear Fuel Cycle

Once the uranium is mined and milled, it is shipped in U3O8 (Yellowcake) form to a conversion facility. This conversion facility takes the U3O8 and converts it to UF6 (Uranium Hexafluoride). Due to its properties, this is the form that is used in the enrichment process. So - the natural UF6 then goes to an enrichment facility. There are two major enriching technologies - the Gas Diffusion Enrichment technology (which has been used in the US for decades) and the Centrifuge technology - which the Europeans and Russians have been using (as a side note, the US is now investigating the use of enriching material in centrifuges). At the enrichment plants, the uranium is enriched from its natural state of about 0.711% U235 to typically between 2% and 5% U235 - the range used in commercial power plants. From here, the enriched UF6 typically goes to a fabricator which takes the enriched UF6 and converts it to UO2 (uranium dioxide) which is subsequently pressed into pellets which are then put into fuel rods which are grouped into Fuel assemblies to power nuclear reactors.

So - when the Chairman of the Joint Chiefs states that Iran has enough material for a bomb - it's true - but it is also true that they don't have uranium in the correct form - and, at present, it doesn't look likely that they can produce this material in the near term.