Calculation of Debris Particle Transport on Containment Floor Using Shallow Water Equation

摘要

Debris transport on containment floor following a loss-of-coolant accident is calculated for the APR1400 plant. No switchover to recirculation operation is adopted in the APR1400 design, the debris may be transported from the beginning of the accident and a fully transient analysis of flow field is needed. For the practical purpose of calculation to predict the flow field, two-dimensional Shallow Water Equations is solved using the Finite Volume Method and the Harten-Lax-van Leer scheme is implemented to capture dry-to-wet interface. For the debris particle tracing, a simple two-dimensional Lagrangean particle tracking model is developed, which also includes viscous drag force model on particle. Martin s scheme for searching the hosting cell, and Haselbacher's scheme for considering the particle reflection. The hydraulic solver is validated with a free surface flow experiment in an open channel. The present model is applied to calculate the transport fraction to Hold-up Volume Tank which is a unique flow path to the containment sump in APR1400. Effects of number, density and size of particles on transport fraction are also investigated.