Abstract: An in-line, multi-stage pump powered by integral canned electric motors. At least two pump units are connected in series in a pipeline. Each of said pump units includes a hollow housing having a hermetically sealed stator mounted therein. The stator is electrically connected to a source of electrical energy. An impeller assembly that includes a tubular suction shroud and impeller is rotatably mounted inside the housing. The impeller assembly includes a hermetically sealed rotor which is mounted around the suction shroud and positioned inside the stator in operative association therewith. Energizing the stator rotates the rotor, which in turn rotates the impeller to pump fluid from the intake end of the housing to the outlet end of the housing. The subsequent pump units add pressure and/or maintains the pressure of the pumped fluid.

Abstract: A two-stage submersible propulsor unit comprises a shroud having a water inlet and a water outlet, a shaft assembly centrally mounted within the shroud, an upstream and a downstream propeller, each of which includes a separate hub rotatably mounted on the shaft assembly, first and second electric motors separately rotating the upstream and the downstream propellers. Each motor includes a rotor mounted around the outer periphery of one of the propellers and a stator mounted around the shroud, and first and second thrust bearing assemblies for absorbing the thrust load generated between the hubs of the first and second propellers and the shaft assembly. Both thrust bearing assemblies are contained within a housing located on the downstream end of the shaft assembly.

Abstract: A nuclear reactor coolant pump for pumping reactor coolant fluid in a reactor coolant system includes a casing, a rotor and an impeller. The casing defines an inlet nozzle for receiving the fluid, a peripheral outlet nozzle for discharging the fluid, and a passage interconnecting the inlet and outlet nozzles through which the fluid can flow from the inlet to outlet nozzle. The rotor extends axially through the casing and has an end disposed adjacent passage. The impeller is mounted to the end of the rotor and disposed in communication with the passage and offset axially from the outlet nozzle of the casing. The impeller is rotatable with the rotor for drawing fluid into the casing through the inlet nozzle and discharging fluid from the casing tangentially through the peripheral outlet nozzle after flow through the passage. The outlet nozzle is composed of first and second wall portions defined above and below a plane extending generally parallel to the rotation axis of the impeller.

Abstract: A vent system for controlling hydraulically actuated drive means for selectively moving pluralities of rod clusters respectively connected to the plurality of drive means between fully inserted positions within the lower barrel assembly of the vessel in telescoping relationship with fuel rod assemblies contained therein, and a fully withdrawn position. Each drive means responds to the reactor coolant fluid pressure and includes a leakage passage and an outlet channel through which a leakage flow may pass under control of the vent system, the latter comprising a valve arrangement, flow restrictors and a common orifice through which the outlet channels are selectively connected to essentially ambient pressure, for establishing a pressure differential within each drive means producing a net force for moving the drive rods and associated clusters to the withdrawn position at which the drive means mechanically latch the fully withdrawn clusters for mechanically supporting same in the fully withdrawn position.