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 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 detachably coupled to each other so that maintenance of the control rod driving apparatus can be performed easily.
Abstract:
Disclosed is a vanadium/titania-based catalyst for removing nitrogen oxides, and a process for removing nitrogen oxides in a flue gas using the same. The vanadium/titania-based catalyst containing a vanadium trioxide and/or vanadium tetraoxide has excellent activity to remove nitrogen oxides in a wide temperature range, particularly, at the low temperature window.
Abstract:
Disclosed is a digital reactor protection system capable of self-excluding a software common mode failure. The system comprises four channels, each channel includes two bistable processors, two local coincidence logic processors, two system interface processors, two initiation logics, two reactor trips, two engineered safety features actuation systems, two maintenance and test panels, and two operator modules ; wherein one bistable processor and local coincidence processor provided in each channel include an A-type CPU and B-type operating system, respectively, and the other bistable processor and local coincidence processor provided in each channel includes a C-type CPU and D-type operating system, respectively ; and wherein the A and C-type CPUs and the B and D-type operating systems are different form each other, respectively, and if a trip condition is produced at the 2of4 (2 out of 4) bistable processor, the local coincidence logic processor transfers a trip signal to the initiation logic to operate the reactor trip and a engineered safety features actuation system.
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:
Provided is a method and apparatus for preventing unexpected dropping of a control rod in a nuclear power plant. The apparatus includes a first current detector which detects current supplied to a control rod drive mechanism, a coil current monitoring module which compares a value of the current detected by the first current detector with a predetermined value and outputs a subsitute power request signal requesting a substitute power to be supplied to the control rod drive mechanism if it is determined that the value of the detected current is not suitable for preventing the dropping of the control rod, and a substitute power supplying unit which supplies the substitute Power to the control rod drive mechanism if the substitute power request Signal is output from the coil current monitoring module. Since the unexpected dropping of the control rod due to a wide variety of single failures and errors can be prevented, the safe operation of the nuclear power plant can be ensured. Also, since costs arising due to an abrupt shutdown can be reduced, the economical effeciency of the nuclear power plant can be improved.
Abstract:
Provided is a combined gas and water spraying fire extinguishing system using common piping. The combined system includes a fire extinguishing gas supply unit, a fire extinguishing water supply unit, a common pipe, a fire detecting unit, a fire control panel, and a deluge valve switch. The fire extinguishing gas supply unit includes a gas container having a storage space in which an injected fire extinguishing gas is stored, a gas pipe connected to the gas container and allowing the fire extinguishing gas to flow therethrough, and a selection valve installed in the gas pipe to open and close the gas pipe. The fire extinguishing water supply unit includes a water pipe connected to a fire extinguishing water container in which a fire extinguishing water is stored and allowing the fire extinguishing water to flow therethrough, and a deluge valve installed in the water pipe to open and close the water pipe. The common pipe is connected to the fire extinguishing gas supply unit and the fire extinguishing water supply unit and installed inside a fire area, and includes a plurality of spray nozzles coupled to end portions thereof such that at least one of the fire extinguishing gas supplied from the fire extinguishing gas supply unit -and the fire extinguishing water supplied from the fire extinguishing water supply unit is sprayed through the plurality of spray nozzles. The fire detecting unit is installed inside the fire area to detect a fire. The fire control panel controls the selection valve to be opened and closed, and opens the selection valve in response to a signal transmitted from the fire detecting unit to let the fire extinguishing gas flowing to the common pipe. The deluge valve switch is electrically connected to the deluge valve to open and close the deluge valve. Therefore, both a gas fire extinguishing system and a water spraying fire extinguishing system can be installed in the combined system in a simple and efficient structure to more surely and effectively save lives and protect properties loss caused by a fire in a building.