Chapter 5 - Framing the Vision of the Media Equation Set

Abstract

In a manner analogous to the general equation set, a media analytical cell will have two surface phases and two aqueous phases. For the purposes of bookkeeping in the equation sets, the media sublayer will be the mass of ionic species and will only be employed in the ion-exchange model. The surface phase will contain the particulate mass that has been either filtered or crystallized to the surface of the media. The aqueous phases will contain both particulates and soluble species as in the general equation set, with the only difference being that in the low-temperature equipment, hydrothermal fluxes will not be modeled because soluble species are no longer predictable by the laws of thermodynamics—they are driven by kinetic phenomena. Depending on the application, many different types of filtration media are commercially available and have been used including sintered metal oxides and silica sand. However, a common choice for high-temperature applications is activated charcoal because it is relatively inexpensive, it is basically inert in primary reactor coolant chemistries, and it can withstand the high-temperature environment of the reactor coolant.