Thermodynamic Modeling of the SRS Evaporators: Part II. The 3H System

Accumulations of two solid phases have formed scale deposits in the Savannah River Site 2H Evaporator system since late 1996. The aluminosilicate scale deposits caused the evaporator pot to become inoperable in October 1999. Accumulations of the diuranate phase have caused criticality concerns in the SRS 2H Evaporator. In order to ensure that similar deposits are not forming in the SRS 3H Evaporator, thermodynamically derived activity diagrams specific to the feeds processed from the 3H Evaporator feed tank (Tank 32) were evaluated

Thermodynamic Modeling of the SRS Evaporators: Part I. The 2H and 2F System

Accumulations of two solid phases occurred in the Savanah River Site (SRS) 2H-Evaporator system since late 1996. The aluminosilicate scale deposits caused the evaporator to become inoperable in October 1999. Accumulations of the diuranate phase have caused criticality concerns in the SRS 2H-Evaporator. In this study, thermodynamically derived activity diagrams, also known as stability diagrams, are developed from historic analytic data from the SRS 2H-Evaporator system feed tank (Tank 43H) and drop tank (Tank 38H) in order to understand the tank chemistry conditions that caused the scale formation in the 2H-Evaporator. The SRS 2F-Evaporator system, which is not precipitating aluminosilicate solids, is modeled for comparison