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Iran, Enrichment, and Arms Control

As tensions are on the rise between the United States and Iran, it is worth examining one of the root causes of the tensions: Iran’s nuclear program. Since its existence became known, Iran has insisted that its nuclear program is only for peaceful purposes. In addition, Iran insists that it has a right to enrich uranium as part of its nuclear program. The United States, along with other Western powers, believe otherwise. As a compromise solution to the problem, in 2015 the Joint Comprehensive Plan of Action (JCPOA) was agreed to by the five permanent members of the United Nations Security Council plus Germany (P5+1) and Iran. It placed strict limits on Iran’s ability to enrich uranium and acquire plutonium, while requiring a strict inspection regime. Until recently, Iran maintained compliance with the agreement. This compromise is seen as the best way to balance between Western and Iranian positions on the issue of Iran’s so-called “right to enrich.”

Image courtesy of the U.S. Department of Energy, © 1984.

While as a signatory state to the Nuclear Non-Proliferation Treaty (NPT), Iran does have a right to nuclear power for peaceful purposes under Article IV of the treaty, it does not have an inalienable right to enrich uranium or to reprocess spent fuel. No non-nuclear NPT signatory state does. The safest compromise to allow for peaceful nuclear power generation is to combine stringent inspection regimes with regulated access to nuclear fuel.

In his book, A Short History of Nuclear Folly, author Rudolph Herzog refers to the gas centrifuge as “after the bomb, the world’s most dangerous invention.” While it is the most common uranium enrichment method today, it was not until captured Nazi scientists Steenbeck and Zippe developed the first functional prototypes in the U.S.S.R., and Zippe’s subsequent recruitment by the U.S. in the 1950s, that the technology became widely usable.[1] Previously used uranium enrichment methods, such as gaseous diffusion, were cumbersome and power intensive. On the other hand, gas centrifuges are relatively small and can be cascaded together to increase enrichment output. In order to enrich uranium in gas centrifuges, it is first converted into the gas uranium hexafluoride (UF6). The gas is then fed into the centrifuge, where it is spun at a sufficiently high velocity to cause the lighter particles containing U235 to collect around the central axis, while the particles containing the heavier U238 separate to the outer sides. The U235 particles are extracted and fed into the next centrifuge in the cascade. This continues until the UF6 reaches the desired enrichment level.

The proliferation danger comes when a state begins cascading large numbers of centrifuges. It takes a large amount of energy to enrich uranium to the 3% to 4% necessary for nuclear power; once the enrichment level reaches 20%, it becomes exponentially easier to enrich to weapons grade levels. Additionally, more active centrifuges mean more quantities of enriched uranium in a state’s stockpile.

Plutonium, unlike uranium, is rarely found in nature. The vast majority of existing plutonium is man-made and occurs as a side product of a sustained nuclear reaction – such as for power generation. As nuclear fuel is “burned,” plutonium builds up in the fuel assemblies. Once the spent fuel has cooled, it can be reprocessed into new reactor fuel (low-enriched uranium). During reprocessing, fission byproducts (including plutonium) are separated and stored for disposal or, more nefariously, for use in weapons manufacturing. If not inspected or monitored, it is possible for plutonium or other fissile materials to be diverted from the reprocessing facilities to clandestine facilities for illegal weapons manufacture.

It is an unfortunate reality that the same technology used to generate low-carbon power is also used to create the most destructive weapons known to humanity. While the NPT outlines the “grand bargain” by which non-weapons states may access nuclear energy, Article IV, cited by Iran as the source of its “right to enrich,” does not mention enrichment. Given the ease of abusing nuclear technology, this is for the best.

It is still possible for Iran to generate nuclear power while maintaining responsible oversight. While the JCPOA is a good step in the right direction, what would be best would be something akin to the U.S. – U.A.E. 123 Agreement. This agreement limits the U.A.E.’s ability to potentially divert fissile materials by forbidding them from reprocessing and implementing stringent inspections. Multilateral organizations such as the Nuclear Suppliers Group are the best way to ensure that important dual-use technologies do not fall into irresponsible hands. The International Atomic Energy Agency (IAEA) Nuclear Fuel Bank, established in 2017, is the best way to supply states with enriched uranium for power production without spreading enrichment technology unnecessarily.  At the end of the day, nuclear technology is simply too dangerous to be left without multilateral  regulation.


John Ashley

John Ashley was the 2017 YPFP Nuclear Security Fellow; he holds a Master of International Policy degree from the University of Georgia, where his studies concentrated in CBRN nonproliferation, export controls, and international security. John also holds a B.A. in History from the University of Georgia, and wrote his thesis on the Great War in Africa. His career goal is to work on the committee staff for the Senate Foreign Relations Committee.
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