A step-by-step approach to validate a new thin-film deposited heating element integrated into a calorimeter from laboratory to irradiation conditions in the JSI TRIGA reactor

This paper presents a step-by-step approach, from laboratory to irradiation conditions, to validate a new thin-film deposited heating element integrated into a single-cell calorimeter. First, the specifications of the new multi-thin-film heating element are given, and the main characteristics and performance, obtained thanks to a comprehensive characterization protocol, are detailed. Then, the sensor, which corresponds to a CALORRE-type single-cell calorimeter is presented, and the integration of this new multi-thin-film heating element into the calorimeter is described by focusing on the specific optimization realized. Finally, the irradiation campaign realized in the Jožef Stefan Institute TRIGA Mark II reactor in Slovenia is detailed. The assembly and the irradiation channel are presented. The calorimeter was located in the Triangular Irradiation Channel #1 with natural convection (dry air channel and ambient temperature), and the axial position corresponded to the median plane of the fuel elements. The new multi-thin-film heating element was qualified up to 3.2 × 10 17 n.cm -2 and the evolution of its resistance was compared before and after 3 days of irradiation. Absolute temperatures at specific points were measured as a function of the reactor power from 12.5 kW to 250 kW.