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 2015.
Japan (INFCIRC/549/Add.1-19) reported having 10.7 tons of plutonium in the country and 37.1 tonnes abroad (the 2014 numbers were 10.8 and 37.0 tons respectively). In July 2016 Japan also released a more detailed internal version of this report, "The Status of Plutonium Management in Japan".
Belgium (INFCIRC/549/Add.3-15) declared "less than 50 kg" of separated plutonium in all categories. It is likely that all material belongs to foreign bodies (900 kg was reported in this category in 2014).
France (INFCIRC/549/Add.5-20) reported having 79.7 tons of separated unirradiated plutonium in its custody. Of this amount, 16.9 tons belongs to foreign countries, so the amount of plutonium owned by France is 62.8 tons. Of the total amount of 79.7 tons, 43.6 tons of plutonium are in storage, 8.9 tons in fabrication process, 26.7 tons is in unirradiated MOX fuel. The remaining 0.5 tons includes reprocessing plant holdup and plutonium at research facilities.
The United States - (INFCIRC/549/Add.6-19) declared 49.0 tons of separated plutonium, of which 4.6 tons are in MOX fuel and 44.4 tons are "held elsewhere" (most of this material is believed to be in weapon components). The numbers for separated and excess plutonium have not changed since the 2011 declaration.
The United Kingdom (INFCIRC/549/Add.8-19) declared the total of 129.4 tons of plutonium in the country, of which 23.2 tons belong to foreign bodies. The national U.K. stock is therefore 106.2 tons. Of the total of 129.4 tons, 125.2 tons are in storage, 0.8 tons are in fuel fabrication process, 1.9 tons - in MOX. The remaining 1.5 tons are "held elsewhere".
Russia (INFCIRC/549/Add.9-18) reported 55.4 tons of civilian plutonium. This includes 53.1 tons of material in storage, 1.5 tons of plutonium in unirradiated MOX and 0.8 tons of plutonium stored elsewhere. The numbers in 2014 were 52, 0.3 and 1.3 tons respectively for the total of 53.6 tons
I addition to reporting plutonium stocks, some countries also submit data on their civilian HEU:
Germany reported 0.3 tonnes of HEU in research reactor fuel, 0.93 tonnes of HEU in irradiated research reactor fuel, and 0.03 tonnes in the category "HEU held elsewhere." The numbers have not changed since 2014.
France declared 4598 kg of HEU (4563 kg in 2014), of which 3004 kg is unirradiated material - 781 kg of HEU at fuel fabrication or reprocessing plants, 98 kg at civil reactor sites, 2125 kg at various research facilities. Also declared are 1593 kg of irradiated HEU - 142 kg at civil reactor sites and 1451 kg in other locations.
The United Kingdom declared 1404 kg of HEU (1398 kg in 2014), of which 1267 kg is unirradiated material - 2 kg at enrichment plants, 351 kg at fuel fabrication or reprocessing plants, 914 kg at various research facilities. Also declared are 137 kg of irradiated HEU - 5 kg at civil reactor sites and 132 kg in other locations.