CHARACTERISATION OF SIZE, SHAPE AND MOTION BEHAVIOUR OF INSULATION PARTICLES IN COOLANT FLOW USING IMAGE PROCESSING METHODS

摘要

The investigations for insulation particle genesis and transport gain in importance regarding the reactor safety research for Pressurised Water Reactors (PWR) and Boiling Water Reactors (BWR). All types of loss-of-coolant accidents (LOCA) as well as short and long term behaviour of emergency core coolant systems were considered for analysis. A gist of these investigations is the development of 3-D-models simulating two-phase flow consisting of water and insulation particles in large geometries. The background of experimental investigations consists of the following parts: 1. generation of a wide data base, 2. development and validation of CFD-models (computational fluid dynamics) for the description of insulation particle transport phenomena in flows. These analysis will be carried out for various geometric and fluidic boundary conditions, as well as sedimentation, resuspension, agglomeration, clogging and increasing of differential pressure at hold-up devices. Three plexiglass test facilities were built for exploration of the mentioned single phenomena. Especially modern flow measurement and digital image processing technologies were applied.