Article dated June 2025 What is uranium enrichment and how is it used for nuclear bombs? A scientist explains
Most civilian nuclear reactors use “low enriched uranium” that’s been enriched to between 3% and 5%. This means that 3–5% of the total uranium in the sample is now uranium-235. That’s enough to sustain a chain reaction and make electricity.
To get an explosive chain reaction, uranium-235 needs to be concentrated significantly more than the levels we use in nuclear reactors for making power or medicines.
Technically, a nuclear weapon can be made with as little as 20% uranium-235 (known as “highly enriched uranium”), but the more the uranium is enriched, the smaller and lighter the weapon can be. Countries with nuclear weapons tend to use about 90% enriched, “weapons-grade” uranium.
According to the International Atomic Energy Agency (IAEA), Iran has enriched large quantities of uranium to 60%. It’s actually easier to go from an enrichment of 60% to 90% than it is to get to that initial 60%. That’s because there’s less and less uranium-238 to get rid of.
This is why Iran is considered to be at extreme risk of producing nuclear weapons, and why centrifuge technology for enrichment is kept secret.
Ultimately, the exact same centrifuge technology that produces fuel for civilian reactors can be used to produce nuclear weapons.
Inspectors from the IAEA monitor nuclear facilities worldwide to ensure countries are abiding by the rules set out in the global nuclear non-proliferation treaty.
While Iran maintains it’s only enriching uranium for “peaceful purposes”, late last week the IAEA board ruled Iran was in breach of its obligations under the treaty.
https://science.anu.edu.au/news-events/news/what-uranium-enrichment-and-how-it-used-nuclear-bombs-scientist-explains#:~:text=Most%20civilian%20nuclear%20reactors%20use,chain%20reaction%20and%20make%20electricity.