Nuclear bomb

Iran's pursuit of nuclear weapons centers on producing weapons-grade uranium. Here's what reports about Iran enriching uranium indicate about its progress ...

Iran has also begun to restrict international monitoring of its nuclear facilities. So far, however, Iran has not decided to begin production of weapons-grade (90%) enriched uranium, even though it is technically capable of doing so. Since the U.S. withdrew from the nuclear deal, Iran has gradually exceeded the agreement’s limits. As a result, modern nuclear weapons based on uranium typically use uranium enriched to 90% to 93% U-235, which is known as weapons-grade uranium, for the primary fuel. The 2015 nuclear deal between Iran, the U.S. China, France, the United Kingdom, Russia and Germany put significant restrictions on Iran’s nuclear program, in return for relief from a number of international sanctions. It also dismantled for storage inside Iran most of its IR-1 centrifuges and all of its more advanced IR-2 centrifuges. As these more powerful advanced centrifuges were installed, breakout time would probably have shrunk to about a few months by year 15 of the deal. At its two principal enrichment facilities, Natanz and Fordow, Iran was operating about 18,000 first-generation IR-1 centrifuges and about 1,000 second-generation IR-2 centrifuges. Generally speaking, lower levels of enriched uranium, such as uranium with 5% U-235, are commonly used for nuclear reactor fuel. The uranium-235 isotope can be used to generate nuclear power for peaceful purposes, or nuclear explosives for military purposes. But larger amounts of lower-enriched uranium can also work. Natural uranium contains two main isotopes, or forms whose atoms contain the same number of protons but different numbers of neutrons.