Innovations in Multi-Physics Methods Development, Validation, and Uncertainty Quantification

Abstract

This paper provides a review of current and upcoming innovations in development, validation, and uncertainty quantification of nuclear reactor multi-physics simulation methods. Multi-physics modelling and simulations (M&S) provide more accurate and realistic predictions of the nuclear reactors behavior including local safety parameters. Multi-physics M&S tools can be subdivided in two groups: traditional multi-physics M&S on assembly/channel spatial scale (currently used in industry and regulation), and novel high-fidelity multi-physics M&S on pin (sub-pin)/sub-channel spatial scale. The current trends in reactor design and safety analysis are towards further development, verification, and validation of multi-physics multi-scale M&S combined with uncertainty quantification and propagation. Approaches currently applied for validation of the traditional multi-physics M&S are summarized and illustrated using established Nuclear Energy Agency/Organization for Economic Cooperation and Development (NEA/OECD) multi-physics benchmarks. Novel high-fidelity multi-physics M&S allow for insights crucial to resolve industry challenge and high impact problems previously impossible with the traditional tools. Challenges in validation of novel multi-physics M&S are discussed along with the needs for developing validation benchmarks based on experimental data. Due to their complexity, the novel multi-physics codes are still computationally expensive for routine applications. This fact motivates the use of high-fidelity novel models and codes to inform the low-fidelity traditional models and codes, leading to improved traditional multi-physics M&S. The uncertainty quantification and propagation across different scales (multi-scale) and multi-physics phenomena are demonstrated using the OECD/NEA Light Water Reactor Uncertainty Analysis in Modelling benchmark framework. Finally, the increasing role of data science and analytics techniques in development and validation of multi-physics M&S is summarized.

An Efficient Scheme for Coupling OpenMC and FLUENT with Adaptive Load Balancing

“…Meanwhile, computer science (CS) and information and communications technologies (ICTs) have also demonstrated their key roles in environmental sustainability [3,4]. Combining CS and ICTs with state-of-the-art physics codes is a cutting edge research in the field of engineering and scientific simulations [5][6][7]. Existing studies show that the use of high-performance computers to perform high accuracy multi-physics simulations can reduce design costs and thereby enhance the safety and economic feasibility of nuclear energy [7,8].…”

Grand Challenges in Nuclear Engineering

“…The challenge here involves optimising the balance between the generation of input data for the data-driven algorithms (Schmidt et al, 2019), which is a difficult issue in its own right as the expected conditions in a reactor are hard to reproduce in a laboratory, and the fundamental physical content, defining the quality and range of validity of a model (Finnis, 2003). A particular question concerns the digital interfaces between the various models involved in an integrated numerical representation of a reactor, where the verification, validation and uncertainty quantification of coupled neutron transport and thermohydraulic models in the context of LWR design and safety analysis were reviewed in (Ivanov and Avramova, 2007;Avramova and Ivanov, 2010;Avramova et al, 2021).…”