OECD-NEA Expert Group on Reactor Systems Multi-Physics: Development of Verification and Validation Guidelines for Multi-Physics Simulations

Abstract Over the past decades, national and multi-national efforts have been established to develop high-fidelity, multi-physics, and multi-scale modeling and simulation (M&S) tools for design and safety challenges for existing and advanced reactors. These tools are being developed and utilized to provide predictive capabilities that enhance safety, improve designs, and accelerate innovation. An expert group on reactor systems multi-physics (EGMUP) was established in 2014 by the OECD Nuclear Energy Agency (NEA) to address specific challenges with validation of such M&S tools with the intent to provide member countries of the NEA with consensus guidance and recommendations and to demonstrate the application of the validation principles. The EGMUP supervises several multi-physics benchmark exercises to develop and demonstrate best practices for validation. This paper will describe the overall mission of the group, provide a description of several of the validation exercises relevant to existing reactor technologies, and summarize key recommendations for validation approaches.