A containment cooling apparatus includes a cooling water tank disposed above a containment; a spray header connected to the cooling water tank via a first communicating pipe, wherein the spray header is disposed on an outside of the containment for spraying cooling water to an outer wall of the containment; a bell shaped shield covering the containment, wherein the cooling water tank is disposed on a top portion of the shield; a space formed between an inner wall of the shield and the outer wall of the containment, wherein the spray header is disposed in the space; an exhaust hole disposed on the top portion of the shield; and a water separator disposed in the exhaust hole and/or the space. The containment cooling apparatus has higher utilization of coolant.

In conjunction with a pressurized water reactor (PWR) and a pressurizer configured to control pressure in the reactor pressure vessel, a decay heat removal system comprises a pressurized passive condenser, a turbine-driven pump connected to suction water from at least one water source into the reactor pressure vessel; and steam piping configured to deliver steam from the pressurizer to the turbine to operate the pump and to discharge the delivered steam into the pressurized passive condenser. The pump and turbine may be mounted on a common shaft via which the turbine drives the pump. The at least one water source may include a refueling water storage tank (RWST) and/or the pressurized passive condenser. A pressurizer power operated relief valve may control discharge of a portion of the delivered steam bypassing the turbine into the pressurized passive condenser to control pressure in the pressurizer.

Provided are a system and method for reducing the atmospheric release of radioactive materials caused by a severe accident. The system includes a steam generator disposed in a containment building, configured to generate steam by using heat of a coolant heated in a nuclear reactor, and connected to a turbine through a main steam line, a decontamination tank connected to the main steam line through a connection line and containing decontamination water for decontaminating the steam delivered from the steam generator and reducing atmospheric release of radioactive materials when a severe accident occurs, and a depressurizing power generation unit disposed on the connection line and configured to generate emergency power while depressurizing the steam delivered from the steam generator toward the decontamination tank when the severe accident occurs.

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 reactor cooling and power generation system according to the present disclosure may include a reactor vessel, a heat exchange section formed to receive heat generated from a core inside the reactor vessel through a fluid, and an electric power production section including a Sterling engine formed to produce electric energy using the energy of the fluid whose temperature has increased while receiving the heat of the reactor, wherein the system is formed to circulate the fluid that has received heat from the core in the heat exchange section through the electric power production section, and operate even during a normal operation and during an accident of the nuclear power plant to produce electric power.

Furthermore, the reactor cooling and power generation system according to the present disclosure may be continuously operated not only during a normal operation but also during an accident to perform reactor cooling, and produce emergency power, thereby improving the system reliability. In addition, the reactor cooling and power generation system according to the present disclosure may facilitate the application of a safety class or seismic design with a small scale facility, thereby improving the reliability due to the application of the safety class or seismic design.

This invention fundamentally changes the basic design principles adopted over the last 50 years that addresses the basic root cause for the station blackout threat faced by all nuclear power plants. The Fukushima nuclear accident that occurred in Japan in 2011 could have turned benign had the plant implemented this invention. It uniquely utilizes the decay heat directly from the reactor core through steam cycles to produce useable power onsite with one or a number of steam turbines of less capacities in combination with compatible electric generators. Such arrangement is reliable to be the onsite energy source. The electric power produced by generators attached to these steam turbines could support necessary all safety functions. The result is that during the first week of urgent threat to the nuclear reactor, there will always be electric power available to run the safety equipment, computers, lighting and other vital devices continuously.

A reactor cooling and power generation system according to the present invention includes a reactor vessel, a heat exchange section to receive heat generated from a core inside the reactor vessel through a fluid, and a power production section having a thermoelectric element configured to produce electric energy using energy of the fluid whose temperature has increased while receiving the heat of the reactor, wherein the system is configured to allow the fluid that has received the heat from the core to circulate through the power production section, and to operate even during an accident as well as during a normal operation of a nuclear power plant to produce electric power.

Also, the reactor cooling and power generation system according to the present invention may continuously operate during an accident as well as a normal operation so as to cool the reactor and produce emergency power, thereby improving system reliability. In addition, the reactor cooling and power generation system according to the present invention may facilitate application of safety class or seismic design with a small scale facility, thereby improving the reliability owing to the application of the safety class or seismic design.

An autonomous self-powered system for cooling radioactive materials comprising: a pool of liquid; a closed-loop fluid circuit comprising a working fluid having a boiling temperature that is less than a boiling temperature of the liquid of the pool, the closed-loop fluid circuit comprising, in operable fluid coupling, an evaporative heat exchanger at least partially immersed in the liquid of the pool, a turbogenerator, and a condenser; one or more forced flow units operably coupled to the closed-loop fluid circuit to induce flow of the working fluid through the closed-loop fluid circuit; and the closed-loop fluid circuit converting thermal energy extracted from the liquid of the pool into electrical energy in accordance with the Rankine Cycle, the electrical energy powering the one or more forced flow units.

A generator is installed on and provides electrical power from a turbine by converting the turbine's mechanical energy to electricity. The generated electrical power is used to power controls of the turbine so that the turbine can remain in use through its own energy. The turbine can be a safety-related turbine in a nuclear power plant, such that, through the generator, loss of plant power will not result in loss of use of the turbine and safety-related functions powered by the same. Appropriate circuitry and electrical connections condition the generator to work in tandem with any other power sources present, while providing electrical power with properties required to safely power the controls.

A passive safety system comprises a heat exchanger, a thermoelectric element, and a fan unit. The heat exchanger is located inside a containment. The heat exchanger allows for temperature of atmosphere in the containment to be reduced. The thermoelectric element is disposed within the heat exchanger. The thermoelectric element is configured to generate electricity due to a temperature difference. The fan unit receives electricity generated by the thermoelectric element. The fan unit is configured to increase flow rate of fluid inside the containment. A nuclear power plant can include the passive safety system.