Abstract: A steel plate structure and a steel plate concrete wall are disclosed. A steel plate structure, which includes: a pair of steel plates, which are separated to provide a predetermined space; a structural member, which is positioned in the predetermined space, and which is structurally rigidly joined to one side of the steel plate in the direction of gravity; and a strut, which maintains a separation distance between the pair of steel plates, can be utilized to reduce the overall thickness of a steel plate concrete wall for efficient use of space, and to reduce the thickness of the steel plates for better welding properties and larger unit module sizes. Also, the axial forces or lateral forces applied on the steel plate concrete wall may be effectively resisted.

Abstract: A system for denitrifying exhaust gas, including a urea water injection unit for supplying urea water and air to a reaction chamber, wherein the urea water injection unit includes: an air supply unit for supplying external air to an injector through an air supply line; a urea water supply unit for supplying urea water to the injector through a urea water supply line; a water supply unit for supplying water to the injector through a water supply line connected to one side of the urea water supply line; a flow control valve for selectively supplying water or urea water to the injector through the urea water supply line; and the injector respectively connected to the air supply unit and the urea water supply unit to selectively discharge air, urea water or water to the reaction chamber through an injection nozzle.

Abstract: Disclosed is a vanadium/titania-based catalyst including natural manganese ore for removing nitrogen oxides and dioxin in a wide operating temperature range and a method of using the same. Specifically, this invention pertains to a vanadium/titania (V/TiO2)-based catalyst, including natural manganese ore, and a method for removing nitrogen oxides and dioxin over a wide operating temperature range, in which the WTiO2 catalyst for selective catalytic reduction of nitrogen oxides and removal of dioxin contained in flue gas includes 5-30 wt % of natural manganese ore.

Abstract: Provided is a modular reactor head area assembly. The modular reactor head area assembly is installed on a reactor head, and includes: a seismic support structure that performs functions of lifting, moving and reinstallation of the reactor head and control rod driving apparatuses, cooling of the control rod driving apparatuses, shielding of missile parts, and supporting with respect to a seismic load, and disperses a load applied to the control rod driving apparatuses; an upper module that is an assembly of components located at an upper portion of the seismic support structure for the control rod driving apparatuses; and a lower module that is an assembly of components located at a lower portion of the seismic support structure for the control rod driving apparatuses. The upper module and the lower module are 252 detachably coupled to each other so that maintenance of the control rod driving apparatus can be performed easily.

Abstract: A system for denitrifying exhaust gas, including a urea water injection unit for supplying urea water and air to a reaction chamber, wherein the urea water injection unit includes: an air supply unit for supplying external air to an injector through an air supply line; a urea water supply unit for supplying urea water to the injector through a urea water supply line; a water supply unit for supplying water to the injector through a water supply line connected to one side of the urea water supply line; a flow control valve for selectively supplying water or urea water to the injector through the urea water supply line; and the injector respectively connected to the air supply unit and the urea water supply unit to selectively discharge air, urea water or water to the reaction chamber through an injection nozzle.

Abstract: Disclosed are a method for preparing a catalyst, which has excellent nitrogen oxide-removal performance and resistance over a wide temperature range, and the use of the catalyst. According to the disclosed method, the oxidation number and surface defects of the catalyst are changed by applying artificial high energy through mechanical ball milling during the preparation process of the catalyst, instead of applying the addition of a precious metal, the deformation of a support and the use of a co-catalyst in order to increase NOx removal activity, such that activation energy for inducing redox reactions can be decreased.

Abstract: A unified fire extinguishing system for a turbine bearing in a power plant, the system puts out a fire that breaks out due to overheating of a lubricant oil due to friction between a turbine shaft disposed inside a turbine bearing housing in the power plant and a turbine bearing that rotatably supports the turbine shaft, and the system includes: a spray nozzle separate from the turbine bearing and disposed inside the turbine bearing housing; and a connection pipe having one end connected to the spray nozzle and the other end connected to a sprinkler pipe, wherein, when a fire breaks out in the turbine bearing housing due to overheating of the lubricant oil, a fire extinguishing fluid supplied from the sprinkler pipe for putting out a fire passes through the connection pipe and is discharged into the turbine bearing via the spray nozzle.

Abstract: Disclosed is a method of preparing a vanadium/titania-based catalyst containing non-stoichiometric vanadium and titanium having excellent ability to remove nitrogen oxides at a wide temperature window, particularly, at a relatively low temperature window of 300° C. or lower.

Abstract: A steel plate structure and a steel plate concrete wall are disclosed. A steel plate structure, which includes: a pair of steel plates, which are separated to provide a predetermined space; a structural member, which is positioned in the predetermined space, and which is structurally rigidly joined to one side of the steel plate in the direction of gravity; and a strut, which maintains a separation distance between the pair of steel plates, can be utilized to reduce the overall thickness of a steel plate concrete wall for efficient use of space, and to reduce the thickness of the steel plates for better welding properties and larger unit module sizes. Also, the axial forces or lateral forces applied on the steel plate concrete wall may be effectively resisted.

Abstract: Provided are a method and apparatus for validating dynamic performance of a control system of a nuclear power plant in operation, without performing a power ascension test. According to the present invention, when the performance of the control system requires to be validated in order to change a control logic or its setpoint of or to replace hardware of the control system, the dynamic performance of the control system may be validated without performing the power ascension test which can be performed only in a trial operation and requires large expenses. In the present invention, a design computer code capable of simulating a transient state of the nuclear power plant is connected to the hardware of the control system, and tests to be performed at the power ascension test or in the transient state of the nuclear power plant are simulated by directly using the hardware of the control system instead of a control system model of the design computer code, in an on-line state.

Abstract: Provided is a wastewater treatment method using an electrodialysis reversal (EDR)-electrochemical wastewater treatment (EWT) combined process, the method including: separating inflow wastewater which contains nitrogen compounds into product water and concentrated water using an EDR facility; and decomposing the concentrated water into target materials to be eliminated from the wastewater in an EWT facility. Provided is a wastewater treatment method for decomposing inflow water containing a nitrogen-containing compound into target materials to be eliminated using an EWT facility alone. According to the wastewater treatment method, product water which is flowed out from an EDR facility can be reused as raw water, and the method guarantees reliability and stability by simultaneously processing recalcitrant COD and T-N in the concentrated water.

Abstract: Provided is a local heatsink welding device and a method of welding using the same. The local heatsink welding device includes a welding torch disposed above welds of two pieces of a base metal placed in contact with each other to be welded, the welding torch welding the pieces of the base metal by melting a welding wire on the welds of the base material and fusing the pieces together; and a cooling unit disposed to be able to spray a low-temperature fluid from the sides of the welding torch, the cooling unit cooling at least a portion of a heat-affected zone formed around the outside of a fusion zone in which the base material is molten during welding.

Abstract: A feedwater control system considering a pressure drop of feedwater control valve in a nuclear power plant and a control method therefor are provided. In the feedwater control system, a first detection unit includes: a flow error signal generator for generating a flow error signal corresponding to a difference between a steam flow signal and a feedwater flow signal; and a water level correction error signal generator for generating a water level correction error signal corresponding to a sum of a water level measurement signal and the flow error signal.

Abstract: A feedwater control system considering a pressure drop of feedwater control valve in a nuclear power plant and a control method therefor are provided. In the feedwater control system, a first detection unit includes: a flow error signal generator for generating a flow error signal corresponding to a difference between a steam flow signal and a feedwater flow signal; and a water level correction error signal generator for generating a water level correction error signal corresponding to a sum of a water level measurement signal and the flow error signal.

Abstract: Provided is a local heatsink welding device and a method of welding using the same. The local heatsink welding device includes a welding torch disposed above welds of two pieces of a base metal placed in contact with each other to be welded, the welding torch welding the pieces of the base metal by melting a welding wire on the welds of the base material and fusing the pieces together; and a cooling unit disposed to be able to spray a low-temperature fluid from the sides of the welding torch, the cooling unit cooling at least a portion of a heat-affected zone formed around the outside of a fusion zone in which the base material is molten during welding.