Application of multiphase flow modeling techniques to the transport of submerged mineral wool fibers

The transport of mineral wool insulation debris, which is generated during all types of loss of coolant accidents (LOCA) could impede the long-term operation of emergency core coolant systems (ECCS) in nuclear power plants. Therefore, a combined experimental and numerical investigation of mineral wool fibers is being pursued to improve the understanding of how ECCS can be undermined by the transport, sedimentation and resuspension of mineral wool fibers.
The application of the Eulerian-Eulerian multiphase flow model to the transport of the fibers is discussed here with regard to the transport of fibers in a racetrack type channel. The study examines the application of closure models such as the Favre-Averaged turbulence dispersion force and the mixture viscosity and the impact that they have on fiber transport. The intention of the study is to aid the experimental part of the study by determining which parameters influence the particle forces and which conditions can be used in analyzing the parameters for further model development and evaluation. The phenomena observed in the calculations correspond qualitatively to preliminary experimental observations.