Papers by Keyword: Nuclear Power Station

Abstract: The microstructure and mechanical properties of a Co-Cr-W-Mo superalloy used for the driving mechanism of nuclear power station were investigated. This alloy was strengthened by W and Mo elements and carbides for high hardness, and an excellent wear resistance was achieved by the high content of carbides. Also, this alloy was of excellent hot-corrosion resistance due to the addition of 29 wt. % Cr. The as-cast alloy was equiaxed, and consisted mainly of γ-Co solid solution, γ/M₇C₃ eutectics and Cr-rich M₇C₃ carbides. The Rockwell hardness was up to 37 - 40. The alloy presented high tensile strength, and the fractography of tensile ruptured specimens was characterized obviously by the interdendritic fracture.

Abstract: Nuclear energy as an economical, safe and clean energy is being increasingly concerned, and nuclear power stations have also been widely built in the world. However, because of the impact from nuclear events, the safety of nuclear power station has been suspected by the public. First, the development situation of the nuclear power station in the world is described. Then the nuclear power station containment is introduced. Meanwhile, the safety performance of nuclear power station containment under external events are analyzed. Some advices on guaranteeing the security work of nuclear power station containment are given.

Abstract: The variations of secondary circuit parameters are limited by the parameters of primary circuit during PWR nuclear power station operation, the primary circuit average temperature should vary at the range of nuclear reactor operating safely. In the existing analysis of secondary circuit thermal efficiency at nuclear power station, the impact of primary circuit average temperature on the secondary circuit thermal efficiency is not taken into consideration. In this paper, the changes of primary circuit average temperature in actual operation are considered, the secondary circuit parameters are calculated according to the model of heat flux transfer between primary and secondary circuit, the thermal efficiency of ideal cycle is chosen as the evaluating indicator of secondary circuit thermal efficiency, the thermal efficiencies of ideal cycle in secondary circuit are calculated under the conditions of varying coolant average temperature with the method of matrix, and the calculated results are basis for the safe and economic operation of nuclear power station.

Abstract: Based on the analysis of the causes and characters of common security risks in nuclear power stations breakwater, using the ground penetrating radar (GPR) to detect breakwater, and to explore the applicability and accuracy. The analysis showed that ground penetrating radar as a non-destructive detection method for the detection of the breakwater is feasible, and the detection accuracy meet the actual requirements of the project, the results can be used for the safety detection and maintenance of the breakwater.

Abstract: This study was base on the welding stress of recirculation pipe at Taiwan Power Company (TPC) which was the first nuclear power station (Chin-Shan) in Taiwan. Technicians or field engineers needed to understand the basic concepts of welding. When using internet processing system, the calculation time for obtaining the required data from the analysis of weld overlay stress had been reduced. Through the connection of internet and server the users entered the welding data from tables to the system, the analysis reports of the weld overlay stress were obtained in a few minutes. Moreover, the reliability in the analysis reports of the weld stress was examined and verified. Therefore, in the study the analysis process and programs developed were able to provide an accurate, simple, and fast analysis results and reports to users. Also, the weld analysis in a recirculation piping system was able to be used in the environmental evaluations.

Abstract: The safe operation of canned motor in nuclear primary pump is very important for nuclear power station. Taken a 5500KW large canned motor of nuclear primary pump as an example, physical model of three dimensional fluid and temperature coupled field was established. The motor temperature distribution under nominal working condition was calculated by using finite volume method. By calculation, revealing the temperature distribution regularity of stator strands, rotor bars, stator core and rotor core, which have significant reference value to structure design of canned motor.

Abstract: The shell is one important part of steam turbo-set condenser. Fangjiashan nuclear power project in Zhejiang Province is the domestic millions-kilowatt class PWR nuclear power plant. Its condenser shell modules have large size and heavy weight. At the same time by turbine house structure restriction, the traditional construction scheme is unable to satisfy the installation requirements. According to the condenser shell module structure characteristics and construction environment, the new construction technology such as four cranes integration operation, many times of changing hook, temporary hanging on the beam of steam turbine house, is studied and adopted. The supporting lifting frame is researched and developed. Four pieces of condenser shell modules with different hanging point size are successfully constructed. This can provide reference for the construction of similar equipment.

Abstract: Nuclear power station has high safety requirements, and the safety systems related to the nuclear island must be checked by hydraulic calculation. In the conventional island, the safe shutdown of the nuclear island most closely relates to the feedwater system, which determines the quantity and quality of the feedwater supply to the steam generator. In this paper, feedwater evolution in case of steamline break will be presented by using Flowmaster hydraulic software, and the results was used as the input for the analysis of security assessment in the nuclear island.

Abstract: The recent shift in the design focus for aeroplanes from strength to damage tolerance has led to a subsequent shift in the focus of Ti alloy research. China first started to research Ti alloys with damage tolerance from the year 2000. The first product stemming from this research is a Ti alloy with high strength, high toughness and damage tolerance (TC21). TC21 exhibits high strength (UTS  1100MPa), high fracture toughness (K1c  70MPa.m1/2) and a low crack propagation rate (da/dN being similar to Ti-6-4 with  annealing). Another Ti alloy, named TC4-DT, has also been produced. It has moderate strength, along with high toughness and damage tolerance (UTS  900MPa, K1c  70MPa.m1/2, da/dN being similar to Ti-6-4 with  annealing). Both TC21 and TC4-DT are now undergoing rapid development, with the former alloy also being applied to a full scale aeronautical application. Both TC21 and TC4-DT have promising futures in the industry. They will be the main Ti alloys with damage tolerance utilised in the Chinese market.

Abstract: Previously, object-oriented inspections have been conducted by the regulatory authority for the welding of electric power generating equipment (hereinafter referred to as “electric structures”) of nuclear power stations in Japan. However, the law related to the welding was recently amended and enforced. The soundness of the welding of the electric structures is verified in a manner that the regulatory authority reviews the utilities’ implementation conditions of welding inspections instead of directly inspecting the welded joints by the authority. This report presents an outline of the Welding Safety Management Review System, which is a review-type inspection.