A review of thermal hydraulics systems analysis for breeding blanket design and future needs for fusion engineering demonstration facility design and licensing

Abstract

The development and demonstration of fusion power plant facilities require advancement of multiphysics modeling capabilities. These capabilities provide an integrated platform for design and analysis of a fusion engineering demonstration power plant. We present a state-of-the-art literature review of the status and needs of multiphysics modeling, including neutronics analysis, and thermal hydraulic/mechanical simulation tools in support of fusion powerplant system design and integration. In this paper we use the Fusion Nuclear Science Facility (FNSF) concept as an example system to assess future needs for advancement of multiphysics modeling capabilities. Specifically, we discuss the latest progress on R&D missions in the literature which are specific to the neutronics and thermal hydraulics design of the breeding blanket concept chosen for the FNSF, the Dual Coolant Lead Lithium (DCLL) blanket. We identify future R&D needs to be addressed through the development of multiphysics modeling capabilities that tie fusion neutronics to tritium breeding ratio (TBR), neutron wall loading (NWL), material damage and transmutation, shutdown dose, and safety assessments. The capabilities will support the design and licensing of a fusion engineering demonstration facility as well as a future engineering demonstration plant.We conclude that more integrated and prototypic tritium experiments must be developed to establish the database needed for the verification and validation of tritium transport simulations. Robust sensitivity and uncertainty (S/U) analysis must be integrated with the facility design to identify the significance of influencing parameters involved in tritium transport, along with quantification of their uncertainties towards output parameters. This enables design optimization of the DCLL blanket during the R&D phase for a fusion engineering demonstration facility. Additional separate- and integral-effects experiments for the validation of the multiphysics analysis is needed for particular components of interest for the DCLL blanket, such as the flow channel inserts (FCIs), along with multi-fidelity simulations which incorporate the magnetohydrodynamic (MHD) effects, and coupled analysis techniques that can capture the interactions between the thermal hydraulic effects and the tritium transport behavior. Simultaneously, the systematic S/U analysis for the multiphysics modeling framework must prove the reliability of the model to help define the technical gaps that need to be addressed by subsequent R&D activities for a fusion engineering demonstration facility. Lastly, S/U analysis of the uncertainties in design parameters for the evaluation of steady and transient safety analysis would be the final requirement that will elucidate the importance of these design parameters, as well as the quantification of their uncertainties on several identified key Figures of Merit (FoM) applicable to the safety analysis to provide guidance for the final design optimization of the DCLL.