Abstract: A hybrid safety injection tank system. The system is pressurized with a safety valve of a pressurizer, which functions as a low pressure safety injection tank and as a high pressure core makeup tank of a nuclear reactor emergency core cooling system. The safety valve is configured to be automatically operated in response to a pressure difference and is installed on a pressure equalization pipe that can realize pressure equalization between the low pressure safety injection tank and the high pressure pressurizer in the event of the nuclear power plant station blackout and power outage.

Abstract: A residual heat removal system for a nuclear power plant. The residual heat removal system for a nuclear power plant may include an air duct provided on an outside of a reactor containment building, a heat exchanger disposed on an inside of the air duct, a first pipe to transfer, to the heat exchanger, steam generated in a steam generator disposed on an inside of the reactor containment building, and second pipe to transfer, to the steam generator, water condensation that is cooled and condensed in the heat exchanger, wherein the heat exchanger is air-cooled using outside air flowing inside of the air duct.

Abstract: A residual heat removal system for a nuclear power plant. The residual heat removal system for a nuclear power plant may include an air duct provided on an outside of a reactor containment building, a heat exchanger disposed on an inside of the air duct, a first pipe to transfer, to the heat exchanger, steam generated in a steam generator disposed on an inside of the reactor containment building, and second pipe to transfer, to the steam generator, water condensation that is cooled and condensed in the heat exchanger, wherein the heat exchanger is air-cooled using outside air flowing inside of the air duct.

Abstract: Provided is a single quantification method of an external event PSA model containing multi-compartment scenarios, including: loading an internal event PSA logic model having core damage as a top event; constituting a mapping table comprising external events containing the multi-compartment scenarios in consideration of information regarding external event occurrence frequencies, external event-induced initiators, and equipments damaged by external events; reflecting the mapping table in the internal event PSA logic model to establish an external event PSA model; calculating a final minimum cut set (MCS) based on the external event PSA model; and calculating a core damage frequency (CDF) value according to the final MCS.

Abstract: The present invention discloses an apparatus and a method for diagnosing abnormal conditions, that quantitatively considers acquisition difficulties between abnormal symptoms provided on a computer screen and quantifies acquisition difficulties of the abnormal symptoms through distinctiveness of measuring devices to exactly diagnose the abnormal conditions even under an improved control environment, making it possible for a user to rapidly and easily diagnose the abnormal conditions that may be generated from a complicated device. With the present invention, the abnormal conditions are diagnosed using the sequential diagnosis technique and the Boolean logic between the abnormal symptoms, making it possible to effectively diagnose the abnormal conditions even under masking effects that may be generated between the abnormal symptoms.

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 discloses an apparatus and a method for diagnosing abnormal conditions, that quantitatively considers acquisition difficulties between abnormal symptoms provided on a computer screen and quantifies acquisition difficulties of the abnormal symptoms through distinctiveness of measuring devices to exactly diagnose the abnormal conditions even under an improved control environment, making it possible for a user to rapidly and easily diagnose the abnormal conditions that may be generated from a complicated device. With the present invention, the abnormal conditions are diagnosed using the sequential diagnosis technique and the Boolean logic between the abnormal symptoms, making it possible to effectively diagnose the abnormal conditions even under masking effects that may be generated between the abnormal symptoms.

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: Provided is a single quantification method of an external event PSA model containing multi-compartment scenarios, including: loading an internal event PSA logic model having core damage as a top event; constituting a mapping table comprising external events containing the multi-compartment scenarios in consideration of information regarding external event occurrence frequencies, external event-induced initiators, and equipments damaged by external events; reflecting the mapping table in the internal event PSA logic model to establish an external event PSA model; calculating a final minimum cut set (MCS) based on the external event PSA model; and calculating a core damage frequency (CDF) value according to the final MCS.