Corium kinematic viscosity measurement

Viscosity is one of the important properties which along with thermal conductivity and coefficient of volumetric expansion, determines convection in molten corium in the case of unfavourable progress of a severe accident in nuclear reactors. The viscosimetric attachment has been designed, developed and built for the purpose of measurement of corium kinematic viscosity with the technique of torsional oscillations. The created experimental devices and procedure for measurement of liquid corium viscosity have been tested and refined over temperature range up to 2800°C. The experimental data of 62UO₂+38ZrO₂ (mol%) melt viscosity have been obtained at temperature ranging from 2600 to 2800°C. The viscosity of 62UO₂+8ZrO₂+30Zr (mol%) melt has been measured at temperatures from 2400 to 2700°C. This work has been performed within OECD RASPLAV Project. The Management Board approves publication of this paper.