An electronic feedwater control system for the experimental boiling water reactor

The feedwater (FW) system for the Experimental Boiling Water Reactor was designed for utmost flexibility to accommodate many different experiments and procedures scheduled for this facility now in operation at the Argonne National Laboratory. Design criteria called for control of level from either the hotwell or the reactor vessel and ability to switch from simple single-element control (level control adjusting the main FW valve) to 2-element control, using either steam flow (SF) or FWF (FW flow) as the second element, to 3-element control using level, FWF and SF. Further, all of these functions had to be adjustable as to their worth, one to the other, and the final resultant signal to the FW control valve had to be adjustable as to proportional band, reset (integral), and rate action (derivative), to allow 3-function control.