Benchmark Comparison of Experimental Data with Thermal-Hydraulic Codes RELAP5-3D and TRACE for a RIA Transient Scenario

The effort to perform transient (TR) testing of nuclear fuel and materials in the United States took an important step in 2017 with the resumption of operations at the Transient Reactor Test (TREAT) Facility at the Idaho National Laboratory. As part of this restart effort, a U.S. Department of Energy–funded grant was tasked with developing a set of computational and experimental benchmarks for prior TR activities in order to assess the capabilities of historically developed codes used to provide the safety case for experimental design and evaluation. One subset of tasks in this project was the development of an experimental facility—the Transient Reactor Test Loop (TRTL) Facility—that would emulate a pump-driven flowing water loop that would be implemented at the TREAT Facility for TR testing of light water reactor fuel. The TRTL Facility was designed and developed at Oregon State University and began operations testing in 2017. Empirical data produced by this new experimental flow loop was benchmarked against a set of codes that represent the standard for use in industrial [Reactor Excursion and Leak Analysis Program–Three Dimensional (RELAP5-3D)] and regulatory [TRAC/Reactor Excursion and Leak Analysis Program (RELAP) Advanced Computational Engine (TRACE)] settings. The findings from those benchmarking activities from the TRTL Facility and the comparisons with the established safety codes are presented here.