Countries: Non-nuclear weapon states
Highly enriched uranium
The IAEA's 2022 annual report lists 156 significant quantities of HEU under comprehensive safeguards in non-nuclear weapon states as of the end of 2022. Without knowing the exact enrichment levels, that means these states hold at least 3.9 tonnes of HEU since, for HEU, a significant quantity is defined as 25 kg of U-235.
In INFCIRC/912 (from 2017) more than 20 states committed to reducing civilian HEU stocks and providing regular reports. So far, only 2 countries have reported under this scheme. At the end of 2018 (time of last declaration), Norway held less than 4 kg of HEU for civilian purposes. As of 30 June 2019, Australia held 2.7 kg of HEU for civilian purposes.
Plutonium
Of the non-nuclear weapon states, Japan owns the largest stock of separated plutonium. According to its 2022 declaration, it owned 45.1 tons of the material, of which 9.2 tons were located in Japan. Other countries that own separated plutonium include Spain, Switzerland, Italy, and the Netherlands, which own civilian plutonium that is stored abroad.