A pump leakage mitigation device includes one or more clamp arms on an outer surface of a pump that can be driven by a biasing element to seat against a shaft of the pump to seal or reduce fluid flow through a breakdown of the pump. The biasing element engages only at threshold temperatures, such as those associated with breakdown orifice failure when additional sealing may be necessary. Clamp arms of any number and shape can be used to achieve the desired seal and based on the pump geometry. A sealant surface and/or keeping mechanism are useable with the leakage mitigation device to enhance fluid flow blockage throughout a pump failure transient scenario. Pump leakage mitigation devices are installed on an outside of a variety of different pump types and can thus be installed, actuated, manipulated, disengaged, and/or removed without having to destroy or disassemble the pump.

A nuclear power plant having a protective superstructure including a first end region configured to cover a nuclear reactor in a containment structure, a second end region opposite the first end region and configured to cover a cooling water pump house, and a central region between the first and second end regions and configured to cover a turbine hall. The superstructure has an oval-shaped plan profile, the oval having a greater degree of curvature at the first end region than at the second end region.

A nuclear power plant having a protective superstructure including a first end region configured to cover a nuclear reactor in a containment structure, a second end region opposite the first end region and configured to cover a cooling water pump house, and a central region between the first and second end regions and configured to cover a turbine hall. The superstructure has an oval-shaped plan profile, the oval having a greater degree of curvature at the first end region than at the second end region.

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 including a rotary active surface and a floating active surface, in which a face of the floating active surface and/or the rotary active surface is micro- or nano-structured by an array of holes or pillars, each hole or pillar having lateral dimensions and a height of between 10 nm and 5 m, the distance between two consecutive holes or pillars being between 10 nm and 5 m.

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 including a rotary active surface and a floating active surface, in which a face of the floating active surface and/or the rotary active surface is micro- or nano-structured by an array of holes or pillars, each hole or pillar having lateral dimensions and a height of between 10 nm and 5 m, the distance between two consecutive holes or pillars being between 10 nm and 5 m.

Disclosed is a nuclear power plant which drives a Stirling engine by means of heat generated in nuclear power plant safety systems during an accident, uses the resulting power directly or generates electric power so as to supply the power to the safety systems, and thus can improve economic efficiency as well as the reliability of safety systems, such as a passive safety system, by operating the safety systems without an emergency diesel generator or external electric power.

Disclosed is a nuclear power plant which drives a Stirling engine by means of heat generated in nuclear power plant safety systems during an accident, uses the resulting power directly or generates electric power so as to supply the power to the safety systems, and thus can improve economic efficiency as well as the reliability of safety systems, such as a passive safety system, by operating the safety systems without an emergency diesel generator or external electric power.

A face plate (10, 11), made of silicon nitride, of a seal package (1) for a sealing system (4) of a shaft (7) of a reactor coolant pump in a nuclear reactor, is intended to ensure sealing between the primary circuit and the atmosphere. The face plate (10, 11) has an active surface covered by a protective layer (13) made from a nonporous material that is chemically inert to pressurized water superheated to a temperature greater than or equal to 200 C.

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.