Code development for the design study of the OMEGA Program accelerator-driven transmutation systems

The Japan Atomic Energy Research Institute carries out R&D on accelerator-driven transmutation systems (ADTS) under the national OMEGA program (Options Making Extra Gains from Actinides and fission products). The code system named ATRAS was developed to analyze neutronics and burnup characteristics of ADTS. It has a unique function of burnup analysis taking into account the effect of the spallation neutron source. ATRAS consists of a hadronic cascade code, a neutron transport code and a burnup analysis code. Utility programs for fuel exchange, pre-processing and post-processing were also incorporated. The neutronics design study of a spallation target as well as the analysis of the neutronics and burnup characteristics of the sodium-cooled ADTS were performed using ATRAS.