Viscosity of molten lithium, thorium and beryllium fluorides mixtures

Considering development of Molten Salt Fast Reactor (MSFR) concept, following Molten Salt fluorides mixtures have been chosen as an object for viscosity studies in this work (in mol%): 78LiF-22ThF(4); 71LiF-27ThF(4)-2BeF(2) and 75LiF-20ThF(4)-5BeF(2). Additionally, the effect of the 3 mol% CeF(3) additives on viscosity of the molten 75LiF-20ThF(4)-5BeF(2) (mol%) salt mixture has been investigated experimentally. The method of torsional oscillations of cylindrical crucible filled by molten fluorides mixture has been chosen for kinematic viscosity measurement at temperatures up to 800-850 degrees C. In temperature ranges, where melts behave as normal liquids, dependences on viscosity vs. temperature are received: v = A exp [B/T(K)), where v - kinematic viscosity, m(2)/s; T- temperature, K. The kinematic viscosity Rout mean squares (RMS) estimated in the assumption about dispersion homoscedasticity is (0.04-0.12) x 10(-6) (m(2)/s). Discrepancies left in the data of viscosity for molten mixtures of LiF, BeF(2) and ThF(4) received by different researchers need further investigations in this area to be continued. (C) 2011 Elsevier B.V. All rights reserved.