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

Abstract

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.

Keywords:

• Dynamical System Scaling
• reactivity-initiated accidents
• BISON
• fuel performance
• Zircaloy cladding

Acknowledgments

The authors would like to thank Charles Folsom, Musa Moussaoui, David Kamerman, and Cole Blakely for their support of this research. The authors would also like to acknowledge the effort from the reviewers whose suggestions and comments have strengthened this paper for the journal’s readers.

This research made use of the resources of the High Performance Computing Center at Idaho National Laboratory, which is supported by the Office of Nuclear Energy of the U.S. Department of Energy (DOE) and the Nuclear Science User Facilities under contract number DE-AC07-05ID14517. The experiment developments, reactor operations, and postirradiation examinations represented in this work were supported through the DOE Advanced Fuels Campaign under DOE Idaho Operations Office contract DE-AC07-05ID14517.