CONCENTRATION LEVELS OF SOLUTES IN POROUS DEPOSITS WITH CHIMNEYS UNDER WICK BOILING CONDITIONS

Concentration levels of highly-soluble impurities and additives in porous deposits with chimneys, when wick boiling is the major mode of heat transfer, have been investigated by a two-dimensional model. Wick boiling promotes the development of high concentration levels of solutes within porous deposits, especially in the region near the intersection of the heating surface and the chimney wall. The maximum concentration factor increases with decreasing porosity; increasing chimney population density; increasing system pressure in the range of interest to LWRs; and approximately exponentially with heat flux and crud thickness. The two-dimensional solute concentration distribution in porous deposits is consistent with limited experimental observations of higher concentration at the chimney wall.