Results from a multi-physics numerical benchmark for codes dedicated to molten salt fast reactors

Marco Tiberga,Rodrigo Gonzalez Gonzaga De Oliveira,Eric Cervi,Juan Antonio Blanco,Stefano Lorenzi,Manuele Aufiero,Danny Lathouwers,Pablo Rubiolo

doi:10.1016/j.anucene.2020.107428

Abstract

Verification and validation of multi-physics codes dedicated to fast-spectrum molten salt reactors (MSR) is a very challenging task. Existing benchmarks are meant for single-physics codes, while experimental data for validation are absent. This is concerning, given the importance numerical simulations have in the development of fast MSR designs. Here, we propose the use of a coupled numerical benchmark specifically designed to assess the physics-coupling capabilities of the aforementioned codes. The benchmark focuses on the specific characteristics of fast MSRs and features a step-by-step approach, where physical phenomena are gradually coupled to easily identify sources of error. We collect and compare the results obtained during the benchmarking campaign of four multi-physics tools developed within the SAMOFAR project. Results show excellent agreement for all the steps of the benchmark. The benchmark generality and the broad spectrum of results provided constitute a useful tool for the testing and development of similar multi-physics codes.

Highlights

Interest in liquid-fuel nuclear reactor research has increased in the last decades (LeBlanc, 2010), especially after the Generation IV International Forum included the Molten Salt Reactor (MSR) in the list of the new generation reactors aiming at delivering a breakthrough in nuclear electricity production in terms of safety, sustainability, and proliferation resistance (Generation International Forum, 2002)
The use of a molten salt both as fuel and coolant leads to unique physics phenomena in molten salt reactors (MSR): internal heat generation in the coolant; thermal feedback induced by fuel expansion; transport of delayed neutron precursors; and, stronger coupling between neutronics and thermal-hydraulics
We have presented a coupled neutronics and fluiddynamics benchmark for multi-physics codes targeting fastspectrum molten salt reactors

Summary

Introduction

Interest in liquid-fuel nuclear reactor research has increased in the last decades (LeBlanc, 2010), especially after the Generation IV International Forum included the Molten Salt Reactor (MSR) in the list of the new generation reactors aiming at delivering a breakthrough in nuclear electricity production in terms of safety, sustainability, and proliferation resistance (Generation International Forum, 2002). The use of a molten salt both as fuel and coolant leads to unique physics phenomena in MSRs: internal heat generation in the coolant; thermal feedback induced by fuel expansion; transport of delayed neutron precursors; and, stronger coupling between neutronics and thermal-hydraulics. These features are absent in traditional solid-fuel reactors, classical codes used in the nuclear community are unsuitable for simulating MSRs behavior ‘‘as they are”. Several dedicated multi-physics tools (e.g., Kópházi et al, 2009; Aufiero et al, 2014; Fiorina et al, 2014; Nagy et al, 2014; Qiu et al, 2016; Laureau et al, 2017; Aufiero et al, 2017; Hu et al, 2017; Lindsay et al, 2018; Cervi et al, 2019; Tiberga et al, 2019; Blanco et al, 2020) have been developed in the context of research projects related to molten salt reactors all around the world (e.g., Serp and Allibert, 2014; Allibert et al, 2016; Dolan, 2017; Zhang et al, 2018) with the aim of performing high-fidelity numerical simulations to assess and optimize the investigated reactor designs

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Results

Conclusion