Removal of Dissolved Gases:

Dissolved gases result from variant sources depending upon that system we examine. In the subsequent discussion, we will address makeup reactor coolant systems, water, secondary facility water systems, a source of dissolved gases, and techniques used to decrease their concentrations to acceptable levels.

Several facilities use raw water as a source for makeup water systems.  Pretreatment of this water is accomplished in several ways from distillation to a series of distinct procedures as displays in Figure. In a pretreatment system same to in which displays in Figure, a resin column holding a cation resin (hydrogen form) is used to erase cations.   The water entering the cation exchanger holds numerous ions involving bicarbonate (HCO^-), sodium (Na⁺), and others (HCO₃^- is one of the main impurities in several raw water systems).  Na ⁺ ions result from the water softener located upstream in the pretreatment system.  In addition to the HCO₃^- ions, raw water holds large amounts of magnesium (Mg⁺⁺) and calcium (Ca⁺⁺), as well as small amounts of other ionic impurities.

Figure:  A Typical Pretreatment System