Comments on 2007 Separated Plutonium Inventory
The separated plutonium inventory for 2007 was released by the Atomic Energy Commission (AEC) on September 9, 2008. We expect that an official English translation will be posted on the following page of AEC's Japanese website in due course:
In the meantime, CNIC has translated some sections of the data (see below).
AEC took over responsibility for accumulating this data from this year. Apparently as a result of the shift of responsibility to AEC, this year figures for plutonium held overseas were only disclosed in tons to the first decimal place (i.e. rounded to the nearest 100kg). In the past figures have been given to the nearest kilogram. CNIC has demanded that AEC explain why it has not published kilogram values this year and that it promptly disclose this information. It is an unfortunate step backwards after the improvements in information disclosure elicited by CNIC over the last two years.
Since 2006, figures for overseas plutonium holdings have only been given for fissile plutonium. Total plutonium has not been given. The slight reduction in fissile plutonium held overseas is due to decay of plutonium-241 to americium-241.
Meanwhile, plutonium held in Japan increased substantially in 2007. Most of the increase was plutonium separated during active testing of the Rokkasho Reprocessing Plant.
Hideyuki Ban (CNIC Co-Director)
English translation of extracts of Japanese plutonium inventory (31 December 2007)