Abstract: A steam generator accident mitigation system is disclosed. A steam generator accident mitigation system to mitigate an accident if the accident occurs in a steam generator installed inside a containment building of a nuclear power plant according to an exemplary embodiment of the present system, the system including: a pressurizing tank which is installed inside the containment building and includes a first cooling water and a non-condensable gas for pressurizing the first cooling water therein; at least one connecting pipe connecting the steam generator and the pressurizing tank; and at least one connecting pipe valve which is installed in the at least one connecting pipe, respectively, and is able to control the amount of opening of the connecting pipe; wherein opening of the at least one connecting pipe valve permits fluid communication between the steam generator and the pressurizing tank.

Abstract: Disclosed herein is a nuclear power plant main steam system that reduces the atmospheric discharge of radioactive materials generated in an accident. The system includes: a decontamination water tank containing decontamination water; and a connection pipe for connecting the decontamination water tank to a main steam pipe which connects a steam generator and a turbine. A main steam safety valve or a connection valve is provided as a three-way valve configured to discharge the generated steam to the atmosphere when an accident occurs within a design basis and to transfer the generated steam to the decontamination water tank when an accident involving damage to nuclear fuel occurs. The main steam system reduces discharge of radioactive materials to the atmosphere when a containment bypass accident (e.g., a steam generator tube rupture caused by high-temperature steam) occurs.

Abstract: A steam generator accident mitigation system is disclosed. A steam generator accident mitigation system to mitigate an accident if the accident occurs in a steam generator installed inside a containment building of a nuclear power plant according to an exemplary embodiment of the present system, the system including: a pressurizing tank which is installed inside the containment building and includes a first cooling water and a non-condensable gas for pressurizing the first cooling water therein; at least one connecting pipe connecting the steam generator and the pressurizing tank; and at least one connecting pipe valve which is installed in the at least one connecting pipe, respectively, and is able to control the amount of opening of the connecting pipe; wherein opening of the at least one connecting pipe valve permits fluid communication between the steam generator and the pressurizing tank.

Abstract: Provided is a combustion controller for a combustible gas of a pressurized water reactor nuclear power plant, and more particularly, to a combustion controller for a combustible gas installed in a rear end of a filtered vent system outside a containment vessel or an external chimney, configured to convert a combustible gas such as hydrogen, carbon monoxide, or the like, into steam, carbon dioxide, or the like, and simultaneously, operate by itself with no external power supply. Accordingly, the combustion controller for a combustible gas can perform stable combustion control with no probability of explosion of hydrogen through a recombining reaction of the combustible gas, prevent discharge of carbon monoxide, which is a toxic gas, and prevent backward flow of the flame through the quenching mesh.

Abstract: Disclosed herein is a nuclear power plant main steam system, which reduces the atmospheric discharge of radioactive materials generated in an accident, the system including: a decontamination water tank containing decontamination water; and a connection pipe for connecting the decontamination water tank from a main steam pipe which connects a steam generator and a turbine, wherein the connection pipe is connected to the decontamination water tank through a main steam safety valve or a connection valve, wherein the main steam safety valve or the connection valve is configured by a three-way valve and is configured to discharge the generated steam to the air when an accident occurs within a design basis and to transfer the generated steam to the decontamination water tank when a severe accident occurs.

Abstract: A nuclear power plant includes a nuclear reactor containment structure housing a nuclear reactor, a pressure vessel containing condensed water therein and having a receiving space located lower than a bottom of the containment structure, a release pipe connecting the containment structure to the pressure vessel such that water vapor and fission products generated in the containment structure in the event of an accident is capable of flowing into the pressure vessel, and a recovery pipe connecting the pressure vessel to the containment structure such that the condensed water received in the pressure vessel is capable of flowing into the containment structure. When a level of the condensed water received in the pressure vessel is higher than a water level in the containment structure, the condensed water flows from the pressure vessel toward the containment structure by a water head difference.

Abstract: Provided is a combustion controller for a combustible gas of a pressurized water reactor nuclear power plant, and more particularly, to a combustion controller for a combustible gas installed in a rear end of a filtered vent system outside a containment vessel or an external chimney, configured to convert a combustible gas such as hydrogen, carbon monoxide, or the like, into steam, carbon dioxide, or the like, and simultaneously, operate by itself with no external power supply. Accordingly, the combustion controller for a combustible gas can perform stable combustion control with no probability of explosion of hydrogen through a recombining reaction of the combustible gas, prevent discharge of carbon monoxide, which is a toxic gas, and prevent backward flow of the flame through the quenching mesh.

Abstract: A nuclear power plant includes a nuclear reactor containment structure housing a nuclear reactor, a pressure vessel containing condensed water therein and having a receiving space located lower than a bottom of the containment structure, a release pipe connecting the containment structure to the pressure vessel such that water vapor and fission products generated in the containment structure in the event of an accident is capable of flowing into the pressure vessel, and a recovery pipe connecting the pressure vessel to the containment structure such that the condensed water received in the pressure vessel is capable of flowing into the containment structure. When a level of the condensed water received in the pressure vessel is higher than a water level in the containment structure, the condensed water flows from the pressure vessel toward the containment structure by a water head difference.

Abstract: The present invention relates to a negative pulse transient signal analysis methods and negative pulse transient signal analysis module for a PC base simulation equivalent circuit capable of grasping and improving error causes through an abnormal signal analysis after configuring a simulation equivalent circuit for a 4˜20 mA instrument unsatisfied in a temperature environmental impact assessment.

Abstract: The present invention relates to a negative pulse transient signal analysis methods and negative pulse transient signal analysis module for a PC base simulation equivalent circuit capable of grasping and improving error causes through an abnormal signal analysis after configuring a simulation equivalent circuit for a 4˜20 mA instrument unsatisfied in a temperature environmental impact assessment.