Iran and Nuclear Proliferation

By Zeb Leonard

In light of recent developments in the Middle East, a considerable amount of attention has been directed at the possibility that Iran may be close to the acquisition of a fission weapon. On 8 November 2011, the Director General of the International Atomic Energy Agency issued to the agency’s board of directors the Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the Islamic Republic of Iran, which is yet to be released to the public. Key to this issue is the concept of uranium enrichment.

Until recently, Iran’s level or uranium enrichment was around 3-5%. This refers to the percentage of the lighter isotope uranium 235, which is ‘fissile’ or able to sustain a fission chain reaction- required for an atomic explosion. In nature uranium is around 0.72% uranium 235. The material has been produced at the Iran’s Natanz Fuel Enrichment Plant. It was initially claimed that enrichment began for the generation of electricity, which requires a level of 3-5% enrichment .

However in 2010 it was announced that Iran reached a level of enrichment of approximately 20% with claims being made that this was required for research into the production of medical isotopes. These are used in nuclear medicine for the treatment of illnesses such as various cancers. According to Gregory Jones of the Non-Proliferation Policy Education Center, material at this level of enrichment can be further enriched, within a short time frame, via a process known as ‘batch recycling,’ up to the levels required to produce a nuclear weapon.  It should be noted that Jones’ estimates of the timeline required for this level of enrichment have been disputed by representatives from the Institute for Science and International Security, including former UN weapons inspector David Albright. There has been a substantial ongoing debate regarding the amount of enriched material Iran is able to produce, but Jones estimates the required ‘trigger quantity’ of uranium to be around 20kgs at around 80-90% enrichment.

The reason for the variation in figures is that the chances of a full yield explosion increase with the amount of sufficiently enriched material present.   Jones also suggests that the technical difficulties involved for Iran to produce an ‘implosion assembly’ would not be insurmountable. This is the required method for building a nuclear weapon with the smallest possible amount of fissile material.  Though disagreeing with Jones’ assessment of Iran’s enrichment timeline, Albright has also made statements to the effect that Iran had the capacity to produce an ‘implosion assembly’ if the requisite fissile material were available.

It is indeed the case that research reactors employed for peaceful applications like the production of medical isotopes have at times made use of highly enriched fuel.  For example, the Australian Nuclear Technology and Safety Organisation website, in reference to their research reactor OPAL states:  ‘OPAL uses low enriched uranium fuel containing just under 20 per cent uranium-235. In terms of security and nuclear safeguards, this is a distinct advantage over earlier research reactors, some of which required enrichment levels as high as 95 per cent uranium-235 (weapons grade).’

Iranian President Mahmoud Ahmadinejad has made statements to the effect his nation would be willing to suspend its domestic enrichment program if suitable fuel be made available for its research reactor. Currently, the US itself imports most of its medical isotopes. It would seem prudent for Western powers to allow Iranian access to medical isotopes themselves, rather than the fuel that could be used to produce them, given the possibility of clandestine ‘batch recycling’.

Zeb Leonard received his PhD from the University of Ballarat in May 2011.  His thesis explored the public debates surrounding British nuclear weapons testing in Australia.