An apparatus having a nuclear reactor comprising a pressure vessel containing primary coolant water and further containing a nuclear reactor core comprising fissile material, a mounting/electrical distribution plate secured entirely within the pressure vessel and configured to be submerged in the primary coolant, a set of control rod drive mechanism (CRDM) units mounted directly on the mounting/electrical distribution plate, and a plurality of cable modules mounted in receptacles of the mounting/electrical distribution plate wherein each cable module includes mineral insulated (MI) cables connected with one or more of the CRDM units, the cable module including its MI cables being removable as a unit from the receptacle of the mounting/electrical distribution plate.