The Multi-fluid Multi-phase Subchannel Analysis Code KAMUI for Subassembly Accident Analysis of an LMFR

摘要

A computer program KAMUI has been developed to simulate multi--dimensional thermal-hydraulic behaviors of the coolant and disrupted fuels in a subassembly under hypothetical accident conditions of a Liquid-Metal Fast Reactor (LMFR) where the strong momentum and thermal coupling of the coolant flow dominates the material relocation. The KAMUI code is based on the subChannel analysis approach to model the fuel pin array geometry and has a two-velocity field, multi-phase/multi-component formulation for transport phenomena with relatively simple but conventional constitutive models. The code has been applied to and validated for a total inlet blockage simulation experiment SCARABEE BE+l. The results show the significance of the radial heat loss through the wrapper tube wall and its influences on the boiling evolution and dynamic behaviors of the coolant and molten clad motion. They also indicate that the multi--dimensional . analysis is essential in evaluating hypothetical subassembly accidents of LMFRs including a large-scale local blockage and a total inlet blockage.