A New critical assembly: STACY

Araki, Shohei   ; Gunji, Satoshi  ; Tonoike, Kotaro ; Kobayashi, Fuyumi ; Izawa, Kazuhiko ; Ogawa, Kazuhiko 

Critical experiments of thermal neutron system are still expected to be playing an important role for wide technical issues. The Japan Atomic Energy Agency (JAEA) is renovating the Static Experimental Critical Facility (STACY) to maintain the experimental capability. The new STACY is designed as a general-purpose criticality facility. Its core mainly consists of low enriched UO fuel rods, grid plates, and light water moderator. The first experiment campaign in the new STACY aims to obtain criticality characteristics of fuel debris, which will be used in validation of criticality analysis methods. The designs of the experimental core configurations are in progress.