Papers by Keyword: Reactor

Abstract: The article analyzes the reasons hindering the mass use of alternative fuels in the field of energy consumption of domestic transport, which for the most part have lower energy and kinetic indicators of combustion in comparison with traditional fuels. A new approach to solving the problem of improving the environmental and energy-saving indicators of combustion of alternative fuels based on their preliminary thermochemical processing - conversion on board a vehicle is presented. The results of a preliminary analytical study of the parameters of the on-board conversion process for a number of potentially acceptable types of alternative fuels are presented in order to assess the efficiency of this process. The possibility of practical implementation of the proposed process for improving the combustion indicators of alternative fuel with an assessment of its efficiency was tested based on the results of experimental approbation in the conditions of full-scale engine tests. According on the results of the study, the expediency of using this process in transport technologies is justified due to the technical simplicity of its implementation and efficiency. Thermocatalytic reactor is the simplest design of a heat exchanger, the mass and dimensional characteristics of which (in the volume of a conventional muffler) ensure the convenience of its installation in the engine exhaust system. The component composition of these products contains reactive compounds that contribute to the improvement of environmental and energy-saving indicators of the fuel combustion process, and an increase in the efficiency of the engine's operating cycle.

Abstract: One of the factors limiting the operation time of nuclear reactor is corrosive wear of the reactor core structural materials and fuel element cladding due to continuous action of water coolant. Thus, for VVER (water-water energetic reactor) type reactors, local galvanic corrosion, which occurs between the surface of fuel element cladding made of zirconium alloy and various grade steel parts of other structural elements is peculiar. A short-circuited galvanic cell formed on the inner wall of Zr + 1% Nb alloy fuel elements is shown. Changes in oxide films thicknesses depending on the time at different water medium acidity are analyzed. A generalized model demonstrating that dissimilar metals in the reactor core (zirconium alloy and steel) form a short-circuited galvanic cell, resulting from which an increase in local corrosion of zirconium alloy occurs is presented.

Abstract: The paper deals with experimental data regarding the effect of internal and external factors on the corrosion decay of Zr1Nb alloy fuel elements. Based on the analysis results, losses of zirconium that transfers to oxide or coolant as per the fuel element wall weight and thickness as well as economic losses from their corrosion decay have been theoretically calculated. To avoid a state-level emergency occurrence, an increase in the fuel element wall thickness up to 660 μm is proposed, which can increase the operating life under the conditions of trouble-free coolant mass transfer hydrodynamic mode.

Abstract: Currently, a new generation of pressurized water reactor for nuclear power plants with an extended service life (up to 60 years) and a guarantee of their complete safety are being designed in Russia. Analysis of the reactor internal elements performance showed, that designed service life cannot be guaranteed if the reactor’s internal parts would be made from currently used stainless steel (18-10 alloy type). Instead of the used steel, to ensure operability, new austenitic stainless steel (16-25 alloy type), with increased resistance to radiation swelling, is being developed for production of forged ring blanks for core baffle. The use of new steel requires revision of the existing metallurgical production technology stages. Therefore in this paper diffusion experiment was carried out to determine the required duration of homogenization. The results are presented in terms of different duration of the high-temperature exposure effect on the liquation heterogeneity equalization. The relation between duration of homogenization and microhardness is also shown.

Abstract: The silicon carbide CVD reactor cleaning process was studied by means of detaching silicon carbide particles, which was formed on the silicon carbide coated carbon susceptor surface during the silicon carbide film deposition. The contact points between the particles and the susceptor surface were etched using chlorine trifluoride gas at temperatures lower than 290 °C for 120 min. During this process, the carbon susceptor covered with the silicon carbide coating film suffered from little damage while achieving cleaning.

Abstract: A SiC dry etcher using chlorine trifluoride (ClF₃) gas was evaluated, particularly about the etching rate distribution. At 100%, the etching rate was high in the center region and was low in the outer region. However, that at 20% showed the opposite profile. This difference was considered to be due to the chlorine trifluoride gas distribution which was built above the gas distributor.

Abstract: The article presents the results of research of the hydrothermal destruction technology of organic fuel materials for the production of steam-flue gas mixture for thermal engines.

Abstract: The basic principle of neutron spectrum measured with time of flight method was simply introduced. The design of the experimental system for the time of flight spectrum detected in the thermal column of the reactor was offered. The most probable neutron energy of the measured thermal neutron was about 0.0248±0.0007eV, and the spectrum average energy was 0.042±0.001eV. The results showed that the measured spectrum was softer than thermal Maxwellian theory spectrum.

Abstract: The fatigue life of the structural materials 15H2MFA and 08H18N10T of VVER-440 reactor pressure vessel under completely reserved total strain controlled tests were investigated. The measurements were carried out with isothermal condition at 260°C on GLEEBLE 3800 servo-hydraulic thermal mechanical simulator. The isothermal low cycle fatigue results were evaluated with the plastic strain based Coffin-Manson law, and plastic strain energy based model as well. It was shown that both methods are able to predict the fatigue life of reactor pressure vessel steels accurately.

Abstract: The calculation results of the operating modes of a plasma reactor for utilizing model water-organic compositions based on a closed nuclear fuel cycle’s inflammable wastes in air plasma are shown. Program complex ANSYS Fluent 6.3 with broad data base of gaseous, liquid and solid materials for calculation of different physical and chemical processes was used.