On September 16, 2014 Japan’s Atomic Energy Commission released its annual report “The Current Situation of Plutonium Management in Japan” (in Japanese). According to the report, at the end of 2013 Japan owned 47,145 kg of plutonium, of which 10,833 kg were in Japan and 36,312 kg – stored abroad. This is an increase of almost three tons (2,904 kg) compared with the 44,241 kg included in the 2012 plutonium report. Part of this increase – 640 kg – is due to a correction of the error in the 2012 report (see the discussion below).
The amount of plutonium in Japan increased by 1,538 kg since the end of 2012. This increase includes 901 kg of plutonium in MOX fuel that was delivered to the Takahama-3 reactor in June 2013 and 640 kg of plutonium in MOX fuel that was unloaded from Genkai-3 reactor in March 2013 (this material should have been included in the 2012report as unirradiated Pu, but it wasn’t). Also, 3 kg of Pu were reported as processing losses at two reprocessing plants.
The 36,312 kg of separated plutonium stored outside Japan is in two countries – 20,002 kg is in the United Kingdom and 16,310 kg in France. The amount of Japan’s material in the UK has increased by 2,950 kg. This increase is likely to be a result of the April 2013 plutonium swap in which Japan assumed ownership of 650 kg of German plutonium stored in the United Kingdom and probably of some other material as well. The amount of Japan’s material stored in France has decreased by 1,585 kg.