Operator’s Contribution on the Improvement of RII Scheme against the Process Operation at PCDF

Regarding the Integrated Safeguards (IS) in Japan, the implementation of IS has been started on September 2004, and the concept has been introduced to the JNC-1 facilities including plutonium conversion development facility (PCDF) since August 2008. Then, random interim inspection (RII) with short notice and reducing person-days of inspection (PDI) was introduced instead of traditional scheduled IIV in order to improve the deterrence of the nuclear material diversion with timeliness goal. And it was agreed that it should be evaluated and reviewed because RII was designed when inter- campaign. In JAEA, we decided to restart PCDF campaign to reduce potential safety risks of reprocessing facilities. It means that rest of plutonium nitrate solution in facilities is converted to MOX powder from April 2014 to avoid hydrogen explosion risk. To adopt the RII scheme to the process operation in campaign, JAEA proposed a new scheme to JSGO and IAEA without increasing PDI and reducing detection probability. As a result of the discussion, it was agreed and successfully introduced since March 2014. The new scheme for PCDF consists of scheduled inspection (fixed-day RII), reduction of estimated material for the verification, implementation of remote monitoring with data provision, improvement of operational status check list, introduction of NRTA and MC&A data declaration with timeliness. It was designed that the randomness was complemented by improving the integrity of MC&A declaration. Though the operator’s workloads for information provision were increased, we could manage to balance IS requirement with implementation of our operation successfully. This contribution was helped to safeguards implementation and our 2 years operation.