This post contains a summary of INFCIRC/549 reports by the countries that submit annual civilian plutonium declarations that reflect the status of civilian plutonium stocks as of 31 December 2023. The total amount of plutonium declared as civilian was about 374 tonnes, an increase of about 4 tonnes since the end of 2022. Only about 144 tons of this material are under international (IAEA or Euratom) safeguards. The other 230 tonnes are not safeguarded, but are covered by various obligations not to use the material for military purposes.
Japan (INFCIRC/549/Add.1-27) reported owning the total of 44.5 tons of plutonium, 8.7 tons of which is in Japan (the numbers in 2022 were 45.1 tons and 9.2 tons respectively). According to the Status Report on Plutonium Management in Japan - 2023 released in July 2024, out of the 35.8 tons of plutonium abroad, 21.735 tons are in the United Kingdom and 14.097 tons are in France.
Germany (INFCIRC/549/Add.2-27) reported having no separated plutonium in the country for the fourth year in a row. Germany does not report separated plutonium outside of the country. It is believed to be less than 1 ton.
Belgium (INFCIRC/549/Add.3-23) declared no separated plutonium in storage or at reprocessing plants and "not zero, but less than 50 kg" of separated plutonium in other categories. It reported that it had no foreign plutonium as of 31 December 2023.
Switzerland (INFCIRC/549/Add.4-28) reported having less than 2 kg of plutonium in the country (in the "located elsewhere" category). The number has not changed since 2016 (it was "less than 50 kg" in 2015).
France (INFCIRC/549/Add.5-28) reported having 110.7 tons of separated unirradiated plutonium in its custody. Of this amount, 14.45 tons belongs to foreign countries (a small increase from 14.33 tonnes in 2022). Almost all that plutonium - 14,097 kg - belongs to Japan. The amount of plutonium owned by France is 96.25 tons, an increase of 4.38 tons from previous year (91.87 tons).
The United States has not submitted its 2023 report as of 7 March 2025. It is likely that the numbers have not changed since 2022 and as a temporary measure these numbers are used to calculate the totals.
China has not has not submitted its 2017-2023 reports as of 7 March 2025. The last INFCIRC/549 report submitted to the IAEA showed 40.9 kg of separated plutonium as of 31 December 2016.
The United Kingdom has not submitted its 2023 report to the IAEA as of 7 March 2025. However, it released the information about civilian plutonium in the INFCIRC/549 format at the Office for Nuclear Regulation web site. According to these data, the United Kingdom owned 116.8 tons of separated plutonium, a small increase (or adjustment) from 116.4 in 2022. In addition to that, the United Kingdom stores 24.1 tons of foreign plutonium (of which 21.735 tons is owned by Japan and 1.58 tons by Italy).
Russia (INFCIRC/549/Add.9-26) reported owning 64.9 tons of civilian plutonium, a small increase of 0.4 ton from 2022.
In addition to reporting plutonium stocks, some countries also submit data on their civilian HEU:
Germany reported 0.39 tonnes of HEU in research reactor fuel (0.35 tonnes in 2022), 0.94 tonnes of HEU in irradiated research reactor fuel, and 0.01 tonnes in the category "HEU held elsewhere."
France declared 5369 kg of HEU (5312 kg in 2022), of which 3801 kg (3761 kg) is unirradiated material - 573 kg (506 kg) of HEU at fuel fabrication or reprocessing plants, 51 kg (78 kg) at civil reactor sites, 3177 kg (3177 kg) at various research facilities. Also declared are 1551 kg (1533 kg) of irradiated HEU - 40 kg (62 kg) at civil reactor sites and 1528 kg (1511 kg) in other locations.
The United Kingdom reported having 691 kg of HEU (734 kg in 2022). Of this amount, 499 kg is unirradiated HEU (554 in 2022): less than 1 kg of unirradiated HEU is stored at the enrichment plants, less than 1 kg is at civil reactor sites, 412 kg - at fuel fabrication facilities, and 87 kg - at other sites (440 kg and 114 kg respectively in 2022). Irradiated HEU is located at civil reactor sites (5 kg) and other sites (132 kg).