Development of the cooling technology on TRU fuel pin bundle during fuel fabrication process: (3) Development of analytical tool

In the trans-uranium (TRU) fuel bundle fabrication process, a fuel pin is spirally wrapped with a thin wire in order to keep a clearance between fuel pins and is laid horizontally. Air flows into the gaps vertically across the pin bundle so as to suppress temperature increase due to decay heat of TRU during the fabrication. From a safety point of view, an effective cooling is of importance. In the present study, an analytical tool, based on a subchannel thermal-hydraulics simulation, has been developed to investigate the thermal-hydraulic behavior and to predict the maximum temperature and the temperature distribution inside the fuel bundle.