Pressurizer:

Reduction of total gas concentrations within PWRs is generally accomplished through the venting of a steam space. Within those facilities utilizing a pressurizer, the steam space inside the top of the pressurizer is designed to complete this venting operation either intermittently or continuously.  This procedure of decreasing the total gas concentration is commonly referred to as degassification.  A classical PWR pressurizer along with degassification piping is displays in Figure.

Degassification is not generally needed in a BWR since of its design.   As earlier previously, the boiling action within the reactor vessel strips dissolved gases from the water, and they are constantly removed in the condensing phase of the energy cycle.

Figure: Pressurizer