A reactor assembly for a redox flow battery system is disclosed. The reactor assembly may include a plurality of outer frames, a plurality of inner frames, and a rib and channel interlock system integrated in the plurality of outer frames and the plurality of inner frames. In certain embodiments, the rib and channel interlock system may be configured to create a plurality of seal systems enclosing an outer circumference of an electrolyte compartment when the plurality of outer frames and the plurality of inner frames are compressed together in a stack configuration.