Atomic Energy最新文献

The implementation of an investment project for the construction of a nuclear power engineering plant with high-temperature gas-cooled reactors and chemical engineering facilities for the production of hydrogen-containing products according to hydrocarbon reforming method represents a major development task in the field of hydrogen technologies. The product line of a nuclear power engineering plant consists of hydrogen, ammonia, and carbamide. The final product will be determined by the consumer. For effective technical and design solutions, enterprises cooperate to conduct research and development work on fuel, graphite, high-temperature materials, manufacture elements and components of the main reactor plant equipment, and verify calculation codes, at the same time as developing a regulatory framework and concept for the management of spent nuclear fuel and radioactive waste. As well as reviewing the main technical solutions for the project of a four-unit nuclear power engineering plant with high-temperature gas-cooled reactors and chemical engineering facilities for large-scale hydrogen production, the present article provides an estimate of the hydrogen cost price at various prices for natural gas, taking into account the stages of production, liquefaction, transportation, and storage.

The article presents the results of a simulation of the TOSQAN (France) and CSE (USA) experiments on the capture of aerosol fission product simulators by droplets of the spray system using the MAVR-TA code. The calculation results are well-correlated with experimental data. The main mechanisms for capturing aerosol particles by sprayed droplets under conditions of beyond-design-basis accidents are described. Analytical calculations were carried out to study the effect of aerosol particle density on the efficiency of particle removal. According to the performed calculations, the density of aerosol particles has a significant impact on their removal from the atmosphere of the containment.

The current development of lead-cooled reactor plants places the main focus of R&D on the primary circuit of the power plant. However, the high melting point of lead significantly affects the design of the secondary circuit, in particular, necessitating the creation of a special system for heating feedwater at the inlet to steam generators to a temperature that exceeds the melting point of the reactor coolant. The present article substantiates the need for the functional allocation of this system and formulates its main requirements.

The paper considers the development and application of digital twins for nuclear power facilities with the purpose of improving operational safety and cost efficiency. The TERMIT technology for automated simulation is presented to develop comprehensive calculation models of various classes and purposes for full-scale simulation of dynamic processes occurring in nuclear power facilities. The main directions and results of the technology application are provided.

The article describes the basic technical solutions and the composition of units for laser dismantling of spent fuel assemblies and cutting of fuel rods for reactors with a liquid-metal coolant during the processing of spent nuclear fuel. The use of lasers as part of robotic and automated complexes for fuel assembly dismantling and fuel rod fragmentation will reduce the loss of valuable fuel materials, prevent their entrainment, reduce the cost of processing, minimize the contamination of solid radioactive waste with fission products, and optimize primary operations in general.

The study of radionuclide migration is of particular concern in when substantiating safety procedures involved in the deep disposal of radioactive waste in the host rocks of the Yeniseisky site located in Krasnoyarsk Krai. One of the main processes controlling the migration of radionuclides is the sorption by mineral phases of host rocks. The present work aims to obtain quantitative characteristics of ¹³⁷Cs, ²³⁷Np, and ²³⁹Pu sorption by the rocks of the Yeniseisky site under conditions simulating a deep disposal of radioactive waste. The distribution coefficients of ¹³⁷Cs, ²³⁷Np, and ²³⁹Pu were determined depending on the ionic strength and temperature of the solutions after leaching the Mg-K-phosphate compound. Differences in the effect of K⁺ and Mg²⁺ cations on cesium sorption by the rocks were established. At an increase in the temperature, the efficiency of ²³⁹Pu and ²³⁷Np sorption by the rocks increases, while the sorption of ¹³⁷Cs remains almost constant.

The article considers an in-situ method potential for establishing the surface distribution of tritium in the first wall of a fusion reactor using neutron tomography. The method includes the formation of a pulse-periodic flux of accelerated deuterons bombarding the studied surface of the first reactor wall following its saturation with tritium, generation of a fast neutron field according to T (d, n)⁴He reaction, measurement of neutron fluence at given spatial points, and reconstruction of the spatial tritium distribution according to measurement data. An algorithm for such a reconstruction is presented based on an approximate solution to the inverse Fredholm problem.

The paper presents experimentally determined hydrodynamic characteristics of the coolant flow at the outlet of the RITM nuclear icebreaker reactor fuel assembly. The studies were carried out according to Pitot tube measurements based on the theory of hydrodynamic similarity using a model of the fuel assembly outlet with an air working medium. Friction factors were determined for several sections located at the outlet of the fuel assembly. The distribution of the hydrodynamic characteristics of the coolant flow is visualized by cartograms of the axial velocity at the outlet of the fuel rod bundle, in the wide and narrow parts of the nozzle, as well as in the fragments of drain windows in the upper base plate. The flow of the coolant through the central displacer and pipe for conducting the coolant to the resistance thermometer is determined. According to the performed studies, the asymmetric nozzle, coolant sampling pipe of the resistance thermometer, and upper base plate are the essential parameters affecting the formation of the field structure for the axial flow velocity.

The complex task of integrating various information, calculation, and simulation tools into a single system can be implemented using digital twins capable of optimizing design, engineering, and technological solutions, as well as supporting the ongoing operation of facilities. This article presents the results obtained within the development of integrating projects for the facilities of the “Proryv” project area, as well as discussing tools and solutions for creating digital twins, including integral mathematical models as a computational representation of the facility. The main directions for the further possible development of digital twins are considered relative to the construction of facilities, support for their operation, replication of digital twins themselves, and the search for innovative solutions that contribute to improvements in the quality both of the digital twins themselves and the actual created facilities.

The article presents the results of using a multifunctional laser module for remote separation cutting of MIR reactor loop channels. The working conditions and parameters for cutting radioactive equipment are described. Alternative methods, as well as the risks associated with the considered method are analyzed.