Abstract: A motor-driven centrifugal pump for circulating a coolant in a primary circuit of a nuclear reactor comprises a sealed motor unit, a hydraulic part and a shaft which is immersed in the coolant, turned by the sealed motor unit and pumping the coolant by an impeller of the hydraulic part secured to the shaft. The motor unit comprises a dry stator and an immersed rotor, mounted securely on the shaft. The motor-driven pump also comprises an immersed flywheel mounted securely on the shaft between the rotor of the motor unit and the impeller of the hydraulic part, allowing a minimum slowing-down time after the electrical power supply is cut; and an immersed anti-backspin device, configured to mechanically block the rotation of the shaft in a predetermined direction.

Abstract: A motor-driven centrifugal pump for circulating a coolant in a primary circuit of a nuclear reactor comprises a sealed motor unit, a hydraulic part and a shaft which is immersed in the coolant, turned by the sealed motor unit and pumping the coolant by means of an impeller of the hydraulic part secured to the shaft; the motor unit comprising a dry stator and an immersed rotor mounted securely on the shaft. The motor-driven pump also comprises an immersed flywheel mounted securely on the shaft between the rotor of the motor unit and the impeller of the hydraulic part, allowing a minimum slowing-down time after the electrical power supply is cut; the flywheel comprising a vaned wheel generating a circulation of the coolant to cool the motor unit.

Abstract: A motor-driven centrifugal pump for circulating a coolant in a primary circuit of a nuclear reactor comprises a sealed motor unit, a hydraulic part and a shaft which is immersed in the coolant, turned by the sealed motor unit and pumping the coolant by means of an impeller of the hydraulic part secured to the shaft; the motor unit comprising a dry stator and an immersed rotor mounted securely on the shaft. The motor-driven pump also comprises an immersed flywheel mounted securely on the shaft between the rotor of the motor unit and the impeller of the hydraulic part, allowing a minimum slowing-down time after the electrical power supply is cut; the flywheel comprising a vaned wheel generating a circulation of the coolant to cool the motor unit.

Abstract: A motor-driven centrifugal pump for circulating a coolant in a primary circuit of a nuclear reactor comprises a sealed motor unit, a hydraulic part and a shaft which is immersed in the coolant, turned by the sealed motor unit and pumping the coolant by an impeller of the hydraulic part secured to the shaft. The motor unit comprises a dry stator and an immersed rotor, mounted securely on the shaft. The motor-driven pump also comprises an immersed flywheel mounted securely on the shaft between the rotor of the motor unit and the impeller of the hydraulic part, allowing a minimum slowing-down time after the electrical power supply is cut; and an immersed anti-backspin device, configured to mechanically block the rotation of the shaft in a predetermined direction.

Abstract: A turbopump pumps a fluid of high viscosity. The pump has an inlet and an outlet. The pump is disposed on a shaft. A turbine has a separate inlet and a separate outlet from those of the pump. The turbine is disposed on the same shaft as the pump. A vehicle liquid has a viscosity less than that of the fluid and is miscible with the fluid. The vehicle liquid is conducted under pressure to the inlet of the turbine, such that a portion of the partially pressure-relieved vehicle liquid exits from the turbine as solvent liquid and is admixed to the fluid in a chamber disposed before the inlet to the pump. Thus, the viscosity of the mixture is reduced. Such that the mixture of solvent liquid and fluid is suctioned from the inlet of the pump. A plurality of injection channels are disposed in the chamber.