Uranium is one of the few elements suitable for nuclear fission applications. However, when mined straight from the earth, natural uranium contains about 99.3 percent uranium-238 or U-238 isotope and around 0.7 percent uranium-235 or U-235 isotope.
Note that U-238 is not fissile. The fissile U-235 isotope is needed to generate and sustain a nuclear reaction. This means that natural uranium cannot be readily used for nuclear fission reactions. This is also the reason why uranium enrichment is a critical part of developing and deploying relevant nuclear technologies.
Enriching uranium or uranium enrichment involves increasing the amount or concentration of the fissile U-235 in natural uranium. The process centers on separating U-235 from U-238 via methods like gas centrifuge and the older gaseous diffusion technique.
There are two broad classifications of enriched uranium. These are low-enriched uranium or LEU and highly enriched uranium or HEU. LEU contains 3 to 5 percent U-235. It is used for nuclear reactors intended for power generation. HEU contains more than 20 percent U-235 and it can go up to 90 percent for weapons-grade HEU.
Legality of Uranium Enrichment According to International Law
The Treaty on the Non-Proliferation of Nuclear Weapons
Uranium enrichment itself is not inherently illegal under international law. However, because the particular element has a dual-use nature, meaning that it can be enriched and used for productivity and the development of weapons of mass destruction, a global nuclear policy was established and adopted to promote the non-proliferation of nuclear weapons.
The Nuclear Non-Proliferation Treaty or NPT is the cornerstone of global nuclear policy. It allows non-nuclear-weapon states to develop nuclear technology for peaceful purposes, including uranium enrichment, as long as it is declared and placed under the safeguards or regular monitoring of the International Atomic Energy Agency or IAEA.
Signatories to the NPT can essentially enrich uranium and agree to welcome IAEA delegates for regular inspections of nuclear facilities. Note that the IAEA is an independent intragovernmental organization founded in 1957 through the IAEA Statute. It is a non-state actor that reports to the General Assembly and the Security Council of the United Nations.
It is also worth mentioning that the IAEA preceded the NPT. The NPT was signed in 1968 with the main goals of preventing the spread of nuclear weapons and weapons technology, promoting cooperation in the peaceful uses of nuclear energy, and advancing further the goal of achieving nuclear disarmament and complete disarmament.
Countries and states that are signatories to the NPT are classified into two categories. These are non-nuclear-weapon states and nuclear-weapon states. The treaty recognized five nuclear-weapon states to achieve global consensus and as part of a geopolitical compromise. These are China, France, Russia, the United Kingdom, and the United States.
Responsibilities of the International Atomic Energy Agency
The IAEA essentially serves as the verification and enforcement arm of the NPT. Its main role is to ensure that countries live up to their treaty obligations. Both the NPT and IAEA complement one another. Hence, because the NPT is a legally binding deal, it provides the IAEA with the legal framework to deploy a specific safeguards agreement.
Specifically, upon signing the treaty, non-nuclear-weapon states must sign another agreement called the Comprehensive Safeguards Agreement with the IAEA. This formalizes the right of IAEA to regulable inspect declared nuclear sites or facilities, monitor all relevant nuclear materials, and confirm compliance with nuclear non-proliferation obligations.
Inspection involves regular monitoring of uranium enrichment activities, initial review of facility designs, accounting for all declared materials, installing and operating surveillance equipment, and taking environmental samples. The IAEA reports to its Board of Governors and the U.N. Security Council if it finds evidence of agreement violations.
Note that Article IV of NPT also empowers the IAEA to promote access to nuclear technology for peaceful uses apart from power generation. These include applications in medicine and agriculture. The organization provides training, technology sharing, and safety guidance to NPT signatories while monitoring and ensuring the non-proliferation of nuclear weapons.
Enriching Uranium by Non-NPT and NPT Signatories
Remember that uranium enrichment is not illegal by default. A country that has not signed the NPT has no legal obligation to limit enrichment activities. However, because of the dual-use nature of uranium, all enrichment activities tend to attract intense international security. The workaround is for a superpower to exert political and economic pressures.
The U.N. Security Council may impose sanctions or demand inspections. Moreover, because the nuclear non-proliferation treaty has a considerable number of signatories, these countries can work together to exert economic pressure through economic sanctions. Non-signatories could also be cut off from relevant technologies and supplies.
Note that India, Israel, and Pakistan did not sign the NPT. All have nuclear weapons. India faced sanctions in the past but is now considered a de facto nuclear weapons state. The same is true for both Israel and Pakistan. North Korea withdrew from the treaty in 2003. It faced sanctions from the United States and other Western allies as a consequence.
Iran signed the NPT in 1968 and ratified it in 1970. Hence, as a non-nuclear-weapon state, it should be committed to never acquiring or developing nuclear weapons, accepting IAEA safeguards on all nuclear material and facilities, and using nuclear technology for peaceful purposes like power generation and medical research and applications.
However, beginning in the early 2000s, the IAEA found that Iran had conducted undeclared nuclear work. This includes uranium enrichment of up to 60 percent U-235. The country claims that this is for peaceful use. Moreover, after the U.S. withdrew from the Iran Nuclear Deal, Iran has limited or denied IAEA access to its declared nuclear facilities.
Understanding the Legality of Uranium Enrichment in a Nutshell
Uranium enrichment is legal. There is no international law preventing state actors from enriching natural uranium. However, because of the dual-use nature of this element, one that could be used for power generation and the other for the development of weapons of mass destruction, uranium enrichment activities are a contentious issue.
The Nuclear Non-Proliferation Treaty provides an agreement for countries to partake in the global effort to prevent the proliferation of nuclear weapons and promote the use of radioactive materials like uranium for peaceful purposes like power generation. This legally binding deal also gives its signatories better access to relevant technologies and competencies.
Nevertheless, because countries are not obligated to sign the treaty and because there are no laws or frameworks against developing nuclear technologies, each is free to pursue uranium enrichment activities. The only workaround against these countries is to exert political and economic pressures to signal disapproval and force norm-compliance.