According to a report, inspectors had detected uranium particles enriched up to 84% in Iran’s nuclear reactor.
- The IAEA, a United Nations agency based in Vienna, has not denied the report, saying only “that the IAEA is discussing with Iran the results of recent agency verification activities.”
- Uranium at 84% is at nearly weapons-grade levels of 90% — meaning any stockpile of that material could be quickly used to produce an atomic bomb if Iran chooses.
- Iran’s 2015 nuclear deal limited Tehran’s uranium enrichment to 3.67% — enough to fuel a nuclear power plant. The U.S. unilaterally withdrew from the accord in 2018. Since then, a shadow war between Israel and Iran has erupted across the wider Middle East.
About uranium enrichment
- When uranium is mined, it consists of approximately 99.3% uranium-238 (U238), 0.7% uranium-235 (U235), and < 0.01% uranium-234 (U234). These are the different uranium isotopes.
- The nuclear fuel used in a nuclear reactor needs to have a higher concentration of the U235 isotope than that which exists in natural uranium ore.
- U235 when concentrated (or “enriched”) is fissionable in light-water reactors (the most common reactor design in the USA). Uranium-235 and U-238 are chemically identical, but differ in their physical properties, notably their mass.
- The nucleus of the U-235 atom contains 92 protons and 143 neutrons, giving an atomic mass of 235 units.
- The U-238 nucleus also has 92 protons but has 146 neutrons – three more than U-235 – and therefore has a mass of 238 units.
- The 1.27% difference in mass between U-235 and U-238 allows the isotopes to be separated and makes it possible to increase or “enrich” the percentage of U-235.
- All present and historic enrichment processes, directly or indirectly, make use of this small mass difference.
- During fission, the nucleus of the atom splits apart producing both heat and extra neutrons. Under controlled conditions, these extra neutrons can cause additional, nearby atoms to fission and a nuclear reaction can be sustained.
- The heat energy released, by the controlled nuclear reaction within the nuclear reactor, can be harnessed to produce electricity.
- Commercially, the U235 isotope is enriched to 3 to 5% (from the natural state of 0.7%) and is then further processed to create nuclear fuel.
- Uranium used for nuclear weapons would have to be enriched in plants specially designed to produce at least 90% U-235.
