Developments in thermal-hydraulic sub-channel modeling for whole core multi-physics simulations

Abstract

The focus of this article is on current developments of thermal-hydraulic sub-channel codes and associated nuclear fuel rod models for high-fidelity light water reactor (LWR) core multi-physics applications. The advanced thermal-hydraulics sub-channel code CTF is selected as an example. CTF is a shortened name given to a version of the legacy code COBRA-TF. Reactor Dynamics and Fuel Modeling Group at North Carolina State University and Oak Ridge National Laboratory are jointly developing CTF. The code has been integrated in the Consortium for Advanced Simulation of LWRs Virtual Environment for Reactor Applications code system. Within the CTF user’s group, the code is being used for different applications in academia, research institutions and industry. Recent developments and applications of CTF for LWR multi-physics modeling and simulation and associated verification, validation, and uncertainty quantification analyses are summarized. In addition, acceleration techniques and parallelization strategies for improving the computational efficiency for whole LWR core sub-channel calculations are briefly introduced. Special attention is given to the high-to-low fidelity model information approach for CTF improvements. Recent developments related to residual-based sub-channel equations and physics-informed data-driven modeling are discussed.