Overview of criticality safety experiments in NUCEF and reassessment of STACY reflecting new regulatory requirements

Miyoshi, Yoshinori

The Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF) is one of the largest research facilities in JAEA. Multipurpose research and development of advanced technology have been made particularly on the reprocessing technology and trans-uranium waste management. This report introduces the criticality safety experiments with the STACY and TRACY. Since the accident in Fukushima Daiichi Nuclear Power Station in March 2011, it became necessary to reevaluate the safety license of many research facilities such as research reactor, critical facility, fuel treatment facility. In NUCEF, reassessment of the modification program of STACY from fuel solution-type to fuel rod-type is on going. This report mainly presents the principle and technical issues of safety reassessment of the STACY modification based on the new regulatory requirements.