Nuclear reactor internal hydraulic control rod drive mechanism assembly

摘要

A control rod drive system for a nuclear reactor that employs hydraulic cylinders to operate a conventional plunger/gripper drive system to incrementally move control rods into and out of the core of a reactor. The pressure differential for driving hydraulic pistons within the cylinders is obtained from the difference in pressure between the outside and inside of the core barrel of the reactor and control of the pistons is obtained from external solenoids attached to the reactor control system. The external solenoids regulate a charging pump feed to Poppet valves that control the hydraulic feed to the cylinders. A hydraulic piston/cylinder drive is also provided for the shutdown rods which operate in either an all in or out of the core condition.

主权项

1. A nuclear reactor power generating system having a nuclear reactor comprising:
a reactor vessel including a lower section and a removable upper head having a horizontal span closing off the lower section and forming a pressure vessel; a reactor core housed in the lower section and comprising a plurality of fuel assemblies; and a control rod assembly including at least one control rod that is driven into or out of a corresponding one of the plurality of fuel assemblies, a drive rod connected to the control rod for driving the control rod into and out of the corresponding fuel assembly and a drive mechanism for activating the drive rod to move along a linear path as it drives the control rod into and out of the corresponding fuel assembly, wherein the drive mechanism comprises at least one hydraulic piston that imparts movement in up plurality of discrete increments to the control rod as the control rod is driven out of the core under a hydraulic power of the hydraulic piston, with the discrete increments occurring in steps that are intermediate to a fully in or fully out respective control rod position and a hydraulic fluid for driving the hydraulic piston is obtained entirely from a reactor coolant from within the reactor vessel and the differential pressure that drives the hydraulic piston of the drive mechanism is taken from the pressure differential across the core at two spaced locations within the reactor vessel.