The present invention discloses a nuclear reactor coolant pump that does not rely on an electric motor, but is operated by means of driving force generated inside a nuclear power plant, so a to be capable of maintaining the safety of the nuclear reactor when the nuclear reactor is operating normally and also in the event of an accident in the nuclear reactor. The nuclear reactor coolant pump comprises: a pump impeller rotatably installed in a first fluid passage of a nuclear reactor coolant system to circulate a first fluid inside the nuclear reactor coolant system; a drive unit receiving steam from a steam generator to generate driving force to rotate the pump impeller, and rotating about the same rotating shaft as the pump impeller to transfer the generated driving force to the pump impeller; and a steam supplying unit forming a passage between the steam generator and the drive unit to supply at least a portion of the steam released from the steam generator to the drive unit.

The present invention discloses a nuclear reactor coolant pump that does not rely on an electric motor, but is operated by means of driving force generated inside a nuclear power plant, so a to be capable of maintaining the safety of the nuclear reactor when the nuclear reactor is operating normally and also in the event of an accident in the nuclear reactor. The nuclear reactor coolant pump comprises: a pump impeller rotatably installed in a first fluid passage of a nuclear reactor coolant system to circulate a first fluid inside the nuclear reactor coolant system; a drive unit receiving steam from a steam generator to generate driving force to rotate the pump impeller, and rotating about the same rotating shaft as the pump impeller to transfer the generated driving force to the pump impeller; and a steam supplying unit forming a passage between the steam generator and the drive unit to supply at least a portion of the steam released from the steam generator to the drive unit.

A method for assisting with the management of a pumping device capable of supplying a circuit of a power production facility with water taken from a natural watercourse is disclosed here. In particular, at least some parameters relating to a watercourse and having an influence on the quantity of materials liable to clog filters are collected. A statistical model is developed that is at least based on historical data for said parameters relating to the watercourse for which clogging of the filters has been observed. Current parameters relating to at least the watercourse are collected and said statistical model is used in conjunction with said current parameters to assess the risk of an influx of clogging materials, and an alert signal for deactivating the pumping device at a selected time is generated on the basis of the assessed risk.

A method for assisting with the management of a pumping device capable of supplying a circuit of a power production facility with water taken from a natural watercourse is disclosed here. In particular, at least some parameters relating to a watercourse and having an influence on the quantity of materials liable to clog filters are collected. A statistical model is developed that is at least based on historical data for said parameters relating to the watercourse for which clogging of the filters has been observed. Current parameters relating to at least the watercourse are collected and said statistical model is used in conjunction with said current parameters to assess the risk of an influx of clogging materials, and an alert signal for deactivating the pumping device at a selected time is generated on the basis of the assessed risk.

A packing seal is provided for a system for sealing the shaft of a primary motor-driven pump unit of a nuclear reactor, intended to ensure sealing between the primary circuit and the atmosphere. The packing seal includes a rotary active surface and a floating active surface, and a face of the floating active surface and/or the rotary active surface is covered by a protective layer made from a material having surface energy greater than 30 mJ/m.sup.2 and an electron donor component less than 15 mJ/m.sup.2.

A packing seal is provided for a system for sealing the shaft of a primary motor-driven pump unit of a nuclear reactor, intended to ensure sealing between the primary circuit and the atmosphere. The packing seal includes a rotary active surface and a floating active surface, and a face of the floating active surface and/or the rotary active surface is covered by a protective layer made from a material having surface energy greater than 30 mJ/m.sup.2 and an electron donor component less than 15 mJ/m.sup.2.

A nuclear steam supply system having a start-up sub-system for heating a primary coolant. In one embodiment, the invention can be a nuclear steam supply system comprising: a reactor vessel having an internal cavity, a reactor core comprising nuclear fuel disposed within the internal cavity; a steam generating vessel fluidly coupled to the reactor vessel; a primary coolant loop formed within the reactor vessel and the steam generating vessel, a primary coolant in the primary coolant loop; and a start-up sub-system fluidly coupled to the primary coolant loop, the start-up sub-system configured to: (1) receive a portion of the primary coolant from the primary coolant loop; (2) heat the portion of the primary coolant to form a heated portion of the primary coolant; and (3) inject the heated portion of the primary coolant into the primary coolant loop.

A nuclear steam supply system having a start-up sub-system for heating a primary coolant. In one embodiment, the invention can be a nuclear steam supply system comprising: a reactor vessel having an internal cavity, a reactor core comprising nuclear fuel disposed within the internal cavity; a steam generating vessel fluidly coupled to the reactor vessel; a primary coolant loop formed within the reactor vessel and the steam generating vessel, a primary coolant in the primary coolant loop; and a start-up sub-system fluidly coupled to the primary coolant loop, the start-up sub-system configured to: (1) receive a portion of the primary coolant from the primary coolant loop; (2) heat the portion of the primary coolant to form a heated portion of the primary coolant; and (3) inject the heated portion of the primary coolant into the primary coolant loop.

A water lubricated composite thrust bearing of a nuclear main pump has a stainless steel base and an engineering plastic layer. The stainless steel base is provided with a concave-convex surface connected to the engineering plastic layer. The concave-convex surface and the engineering plastic layer are compositely molded by means of thermoplastic compound molding. A ratio of the area of the concave-convex surface to the area of an orthographic projection of the concave-convex surface on the stainless steel base ranges from 1.2 to 2. By means of the concave-convex surface and a specific bonding property obtained after fusion of a rough face and the engineering plastic layer, the concave-convex surface is bonded with the engineering plastic layer, thereby forming a reliable composite thrust bearing that is physically connected onto a whole.

A nuclear steam supply system having a shutdown system for removing residual decay heat generated by a nuclear fuel core. The steam supply system may utilize gravity-driven primary coolant circulation through hydraulically interconnected reactor and steam generating vessels forming the steam supply system. The shutdown system may comprise primary and secondary coolant systems. The primary coolant cooling system may include a jet pump comprising an injection nozzle disposed inside the steam generating vessel. A portion of the circulating primary coolant is extracted, pressurized and returned to the steam generating vessel to induce coolant circulation under reactor shutdown conditions. The extracted primary coolant may further be cooled before return to the steam generating vessel in some operating modes. The secondary coolant cooling system includes a pumped and cooled flow circuit operating to circulate and cool the secondary coolant, which in turn extracts heat from and cools the primary coolant.