A survey on calorimetric measurement for development of advanced radioactivity standards

National Metrology Institute of Japan (NMIJ) at National Institute of Advanced Industrial Science and Technology (AIST) holds national standards of radioactivity, and secures the traceability for various radioactivity measurements based on Japan Calibration Service System. It is required to establish radioactivity standards with less uncertainty to ensure safe and efficient utilization of the radioactivity. Present status of the radioactivity standards of NMIJ is reported and the calorimetric measurement method as a candidate to sophisticate radioactivity standard is investigated. (J.P.N.)