Abstract: A semiconductor device includes: a fin-type active region protruding from a substrate and extending in a first direction; at least one nano-sheet spaced apart from an upper surface of the fin-type active region and facing the upper surface of the fin-type active region, the at least one nano-sheet having a channel region; a gate extending on the fin-type active region in a second direction crossing the first direction and surrounding at least a portion of the at least one nano-sheet; a source/drain region on the fin-type active region on both sides of the at least one nano-sheet; and a source/drain protection layer on a sidewall of the at least one nano-sheet and between the source/drain region and the at least one nano-sheet.

Abstract: A semiconductor device includes: a fin-type active region protruding from a substrate and extending in a first direction; at least one nano-sheet spaced apart from an upper surface of the fin-type active region and facing the upper surface of the fin-type active region, the at least one nano-sheet having a channel region; a gate extending on the fin-type active region in a second direction crossing the first direction and surrounding at least a portion of the at least one nano-sheet; a source/drain region on the fin-type active region on both sides of the at least one nano-sheet; and a source/drain protection layer on a sidewall of the at least one nano-sheet and between the source/drain region and the at least one nano-sheet.

Abstract: Disclosed herein is a water-air combined passive feed water cooling apparatus including a water cooling heat exchanger connected to the inside of a containment building to cool down heat of a steam generator using a water cooling method, a cooling tank including the water cooling heat exchanger therein and storing cooling water condensing main steam generated by the steam generator, an evaporative steam pipe connected to the cooling tank, the evaporative steam pipe, into which steam of the cooling water generated by the water cooling heat exchanger in the cooling tank flows, an air cooling heat exchanger connected to the evaporative steam pipe and cooling down and liquefying the steam flowing into the evaporative steam pipe, and a condensed water collecting pipe for refilling the cooling tank with the steam liquefied by the air cooling heat exchanger.

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: Provided is a passive containment air cooling device with an isolated pressure boundary, including a heat exchanger positioned inside and outside a containment, penetrating through an outer wall of the containment to be connected to the containment through a pipe and thus form a closed loop, and including a coolant, an air induction duct circulating air outside the heat exchanger, and a cooled air exhaust unit formed in the air induction duct to increase cooling efficiency of the heat exchanger.

Abstract: A passive high-pressure safety injection system includes a compressor which generates high-temperature and high-pressure steam, a cooling water supply tank which supplies cooling water using the compressed steam, a nuclear reactor which receives the cooling water so that the nuclear reactor is maintained in a cooled state, and an internal circulation prevention structure which is provided in the cooling water supply tank and prevents the cooling water from circulating in the cooling water supply tank.

Abstract: A high pressure safety injection tank (HPSIT) system includes one safety injection tank (HIT) which replaces a core makeup tank (CMT) and a low pressure (approximately 4.3 Mpa or below) safety injection tank (SIT) and which can shift to and operate on a high pressure (approximately 17 Mpa) operation mode, to enable injection of emergency core coolant into a reactor system both under low pressure (approximately 4.3 Mpa or below) and high pressure (approximately 17 Mpa).

Abstract: Disclosed herein is a water-air combined passive feed water cooling apparatus including a water cooling heat exchanger connected to the inside of a containment building to cool down heat of a steam generator using a water cooling method, a cooling tank including the water cooling heat exchanger therein and storing cooling water condensing main steam generated by the steam generator, an evaporative steam pipe connected to the cooling tank, the evaporative steam pipe, into which steam of the cooling water generated by the water cooling heat exchanger in the cooling tank flows, an air cooling heat exchanger connected to the evaporative steam pipe and cooling down and liquefying the steam flowing into the evaporative steam pipe, and a condensed water collecting pipe for refilling the cooling tank with the steam liquefied by the air cooling heat exchanger.

Abstract: Provided is a passive containment air cooling device with an isolated pressure boundary, including a heat exchanger positioned inside and outside a containment, penetrating through an outer wall of the containment to be connected to the containment through a pipe and thus form a closed loop, and including a coolant, an air induction duct circulating air outside the heat exchanger, and a cooled air exhaust unit formed in the air induction duct to increase cooling efficiency of the heat exchanger.

Abstract: A passive high-pressure safety injection system includes a compressor which generates high-temperature and high-pressure steam, a cooling water supply tank which supplies cooling water using the compressed steam, a nuclear reactor which receives the cooling water so that the nuclear reactor is maintained in a cooled state, and an internal circulation prevention structure which is provided in the cooling water supply tank and prevents the cooling water from circulating in the cooling water supply tank.

Abstract: The present invention relates to a longitudinally divided emergency core cooling (ECC) duct in order to efficiently inject safety water to core of a pressurized light-water nuclear reactor. The ECC duct includes side supports for preventing the flow-induced vibration in the annular downcomer, and has structural stability while thermally expanding and contracting. A longitudinally divided ECC duct for emergency core cooling water injection of a nuclear reactor is provided on the periphery of a core barrel of a nuclear reactor, includes an emergency core cooling water inlet facing a direct vessel injection nozzle, and extends in a longitudinal direction of the core barrel. The longitudinally divided ECC duct is divided into a plurality of longitudinally-divided ducts in the longitudinal direction of the longitudinally divided ECC duct.

Abstract: A high pressure safety injection tank (HPSIT) system includes one safety injection tank (HIT) which replaces a core makeup tank (CMT) and a low pressure (approximately 4.3 Mpa or below) safety injection tank (SIT) and which can shift to and operate on a high pressure (approximately 17 Mpa) operation mode, to enable injection of emergency core coolant into a reactor system both under low pressure (approximately 4.3 Mpa or below) and high pressure (approximately 17 Mpa).

Abstract: An emergency core cooling system directly injects emergency core cooling water, which is supplied from a high-pressure safety injection pump or a safety injection tank for a pressurized light water reactor, into a reactor vessel downcomer. A pipe connector is completely removed from between each direct vessel injection nozzle and each injection extension duct installed on an outer surface of the core barrel, which are opposite to each other. An emergency core cooling water intake port, through which the water is injected from each direct vessel injection nozzle, is formed on the surface of each injection extension duct facing an axis of each direct vessel injection nozzle. Thereby, a structure in which a jet of the emergency core cooling water flows into the injection extension ducts is adopted in a hydraulic connection fashion.

Abstract: A safety injection tank, used for quickly injecting emergency core cooling water (ECCW) to a reactor vessel in the case of a cold leg large break accident (CLLBA) in a pressurized water reactor (PWR), is disclosed. The safety injection tank has a gravity-driven fluidic device configured to efficiently change the ECCW injection mode from a high flow injection mode to a low flow injection mode. The gravity-driven fluidic device includes a spring placed in the upper end of the vertical pipe, and a vertically movable water tub placed on the spring so as to be movable in a vertical direction. When ECCW contained in the pressure vessel is discharged and the water level is reduced lower than the height of the tub, the tub is moved downwards such that the lower surface thereof comes into contact with the vertical pipe and closes the high flow inlet port.

Abstract: The present invention relates to a longitudinally divided emergency core cooling (ECC) duct in order to efficiently inject safety water to core of a pressurized light-water nuclear reactor. The ECC duct includes side supports for preventing the flow-induced vibration in the annular downcomer, and has structural stability while thermally expanding and contracting. A longitudinally divided ECC duct for emergency core cooling water injection of a nuclear reactor is provided on the periphery of a core barrel of a nuclear reactor, includes an emergency core cooling water inlet facing a direct vessel injection nozzle, and extends in a longitudinal direction of the core barrel. The longitudinally divided ECC duct is divided into a plurality of longitudinally-divided ducts in the longitudinal direction of the longitudinally divided ECC duct.

Abstract: A direct vessel injection (DVI) nozzle for minimum emergency core coolant (ECC) bypass is disclosed. The DVI nozzle is used in a pressurized light water reactor (PLWR) having a reactor vessel with a reactor coolant system in which a coolant flows into the reactor vessel through a cold leg and passes through a reactor core prior to being discharged to the outside of the reactor vessel through a hot leg. The DVI nozzle, provided to directly inject ECC into the reactor vessel to cool the reactor core during a break in the reactor coolant system, such as a cold leg break (CLB) that may occur in the PLWR, is placed on the reactor vessel at a position horizontally offset from the central axis of the hot leg at an angle of 10° to 30° and is involved within a region defined above the central axis of the hot leg by a distance of 1.5 times the sum of diameters of the hot leg and the DVI nozzle.

Abstract: A direct vessel injection (DVI) nozzle for minimum emergency core coolant (ECC) bypass is disclosed. The DVI nozzle is used in a pressurized light water reactor (PLWR) having a reactor vessel with a reactor coolant system in which a coolant flows into the reactor vessel through a cold leg and passes through a reactor core prior to being discharged to the outside of the reactor vessel through a hot leg. The DVI nozzle, provided to directly inject ECC into the reactor vessel to cool the reactor core during a break in the reactor coolant system, such as a cold leg break (CLB) that may occur in the PLWR, is placed on the reactor vessel at a position horizontally offset from the central axis of the hot leg at an angle of 10° to 30° and is involved within a region defined above the central axis of the hot leg by a distance of 1.5 times the sum of diameters of the hot leg and the DVI nozzle.

Abstract: A safety injection tank, used for quickly injecting emergency core cooling water (ECCW) to a reactor vessel in the case of a cold leg large break accident (CLLBA) in a pressurized water reactor (PWR), is disclosed. The safety injection tank has a gravity-driven fluidic device configured to efficiently change the ECCW injection mode from a high flow injection mode to a low flow injection mode. The gravity-driven fluidic device includes a spring placed in the upper end of the vertical pipe, and a vertically movable water tub placed on the spring so as to be movable in a vertical direction. When ECCW contained in the pressure vessel is discharged and the water level is reduced lower than the height of the tub, the tub is moved downwards such that the lower surface thereof comes into contact with the vertical pipe and closes the high flow inlet port.

Abstract: An emergency core cooling system directly injects emergency core cooling water, which is supplied from a high-pressure safety injection pump or a safety injection tank for a pressurized light water reactor, into a reactor vessel downcomer. A pipe connector is completely removed from between each direct vessel injection nozzle and each injection extension duct installed on an outer surface of the core barrel, which are opposite to each other. An emergency core cooling water intake port, through which the water is injected from each direct vessel injection nozzle, is formed on the surface of each injection extension duct facing an axis of each direct vessel injection nozzle. Thereby, a structure in which a jet of the emergency core cooling water flows into the injection extension ducts is adopted in a hydraulic connection fashion.

Abstract: A direct vessel injection-type pressurized light water reactor (DVI-PLWR), in which an emergency core cooling water (ECC) is directly injected into a downcomer of a reactor vessel, is disclosed. In order to reduce the ratio of ECC bypass from the downcomer to a broken area of a cold leg in the case of a cold leg guillotine break (CLGB), such as a double-ended guillo4tine break (DEGB), a plurality of corrugations, having a V-shaped cross-section, are vertically arranged around each of the inner surface of a pressure vessel and the outer surface of a core barrel at regular intervals, with a vertical groove formed between two neighboring corrugations. The grooves phase-separate the ECC from a high-speed lateral flow of fluid running in the downcomer, and the separated ECC stagnates in the form of vortexes in the grooves, prior to flowing down to the lower section of the downcomer due to gravity.