Verification and Validation of Numerical Models of the Transport of Insulation Debris

Abstract

Mineral wool fibre agglomerates (MWFA), which are released by damage to insulation materials located near to a primary circuit coolant leak, maybe transported to the containment sump strainers, where they can accumulate and compromise the long-term operation of the emergency core cooling system. Numerical models of the transport of MWFA are validated against single effect tests of sedimentation in a quiescent rectangular column and sedimentation in a horizontal flow. MWFA can be modelled as a number of pseudo-continuous dispersed phases of spherical wetted agglomerates. Agglomerate size, density, relative viscosity of the fluid-fibre mixture and the turbulent dispersion influence MWFA transport.