VALIDATION OF RELAP5-3D FOR TRANSIENT SIMULATION OF LEAD-LITHIUM SYSTEMS FOR FUSION APPLICATIONS

With increasing development in fusion technology including the construction and subsequently planned experimental campaign of the International Thermonuclear Experimental Reactor (ITER), validation must be performed for simulation tools used in the design, development, and licensing of future commercial fusion systems. This thesis contains several validation studies for transient simulation of lead-lithium eutectic (PbLi) systems using the RELAP5-3D code. This validation analysis is performed initially using models of systems without the influence of a magnetic field to inspect heat transfer and pressure drop phenomena. The validation study then uses models of systems under the influence of a magnetic field to inspect magnetohydrodynamic (MHD) pressure drop phenomena. We determine that the results from the validation study show excellent agreement to experimental results and that RELAP5-3D is sufficient for modeling PbLi systems for fusion relevant applications.

This following work constructs a model of the Dual-Coolant Lead-Lithium (DCLL) blanket design from the proposed Fusion Nuclear Science Facility (FNSF). This is used to perform a representative startup transient of the FNSF based on limitations of both light water reactors and PbLi tandem mirror systems. This model provides a baseline for thermal-hydraulic analysis of PbLi blanket systems. Suggestions for further improvement of the model are given including the implementation of a multiphysics analysis, the enhancement of the MHD calculation capabilities, and the development of a simple thermomechanical analysis.