Dynamical System Scaling Application to Zircaloy Cladding Thermal Response During Reactivity-Initiated Accident Experiment

New fuel design and development currently require 20 to 25 years to be qualified for use by the nuclear power industry. The thermal-hydraulics community has taken advantage of scaling theory to design reduced-scale experiments that correctly preserve dominant key phenomena while quantifying distorted phenomena. These techniques can be leveraged in the design and analysis of fuel performance experiments to help reduce the timeline associated with fuel design and development. This study uses the Dynamical System Scaling (DSS) method to analyze cladding temperature data from the recent SETH-C experiment in the Transient Reactor Test Facility (TREAT) and accompanying BISON simulations to assess dynamic distortions occurring throughout the fast power excursion transient. The DSS analysis revealed that on the cooldown from peak cladding temperature, the fuel radial power profile is the most sensitive modeling parameter, with a heterogeneous radial peaking factor corresponding to the lowest distortion compared to a uniform energy deposition. For the heatup to PCT, the heterogeneous radial power profile corresponded to the shortest process action. Last, for the heatup to PCT, the gap conductance model sensitivity was quantified using process actionsm and showed that the default light water reactor gap conductance model corresponded to the longest process action.