The neutron fluxes of D–D and D–T tubes with sorbed and stuffed targets are compared. Calculations of the change of the neutron flux in generators when a tube of one type is replaced by a tube of a different type are presented. The influence of the atomic-molecular composition of the ion beam and the target material, the hydride stoichiometry, and the isotopic composition of the gas in the getter is

Work has been performed as part of the implementation of measures to reduce the hazard of irradiated graphite during the decommissioning of uranium-graphite nuclear reactors. Electrochemical decontamination is studied as a method of purifying the indicated wastes from radioactive contamination. The results of experiments on removing 60Co,134,137Cs, 154Eu, and 241Am from the surface of irradiated graphite

Analysis of the problems and potential of two nuclear technologies based on fusion reactions of light nuclei and fission of heavy nuclei shows the following. Independent large-scale development of each one will make it necessary to overcome still unsolved technological, materials science, environmental, and economic problems, raising the question of the expediency of further development of these energy

The development of any energy system, including nuclear, is a lengthy and multi-stage process. To evaluate the outlook, many significant factors outside the nuclear energy system and the uncertainty of future avenues of macroeconomic development must be taken into account. This task requires a multi-criteria approach to the analysis of the competitiveness of the technology using criteria that combine

A clinically available software method has been developed and tested for evaluating tumor dynamics according to size and physical density in adaptive radiation treatment of cancer patients for any cases of imaging of tumor borders, including fuzzy imaging of the tumor borders. The quantitative informativeness of the method is shown.

The results of studies of the intensification of heat-and-mass transfer and mixing of coolant are presented. Justification is given for the design, number, and arrangement of intermediate intensifier plate grids in combination with honeycomb spacer grids in the structural implementation of TVSA-T. The hydraulic and thermo-mechanical constraints of the design are taken into account. It is shown that

In the second half of the 1950s, when all resources of the Soviet Union were directed at making as fast as possible a nuclear bomb as a weapon of deterrence, scientists did not leave any stone unturned in their efforts to convince the managers of the Soviet nuclear project of the need to begin work on the peaceful use of atomic energy. The story of how a decision was made to create the world’s first

The kinetics of a pulsed booster controlled by a high-energy proton beam is examined as a promising source of powerful neutron pulses. A subcritical multiplying assembly based on plutonium dioxide with a reactivity modulator is considered as the pulsed booster. The pulsed booster intensifies neutron pulses generated in a non-multiplying target by the accelerator protons. The parameters of the neutron

An analytic solution is given for a system of first-order inhomogeneous linear differential equations describing the mass transfer of fission products in radioactive decay chains of arbitrary complexity and length by means of a system of an infinite number of working zones separated by radiation safety barriers. The computational procedure is implemented in the TARUSA system of computer codes, making

Some issues concerning the prevention of dangerous radiation exposure of the general public and providing insurance for spacecraft with next-generation nuclear reactors are examined. It is shown that the technical and organizational measures to meet the requirements of international and Russian documents will secure radiation safety for the general public when using spacecraft with nuclear reactors

The 14C emissions from NPP with RBMK-1000 and EGP-6 reactors as well as the yearly population irradiation dose due to these emissions are evaluated. A model is presented for calculating the population irradiation dose due to 14C emissions assuming an equilibrium 14C distribution between local food products and atmospheric air and absence of such an equilibrium for humans as a result of the consumption

Issues concerning the completeness and integrity of a strategy for the development of nuclear energy in Russia to 2050 and the prospects for the period to 2100 are examined. It is shown that questions concerning the final stages of the lifecycle and environmental aspects associated with the use of nuclear technologies are not duly reflected in the strategy. The authors believe that the strategy cannot

The chemical and structural properties of cement compounds, containing radwaste simulators, after exposure to γ-radiation and electrons to absorbed dose 100 MGy are examined. It is shown that the phase composition and surface morphology of samples of cement compounds do not change much and the chemical stability remains satisfactory.

The results of verification of the module for sodium aerosol behavior in moist air in an enclosure on experiments performed using the ATF facility (India) are reported. The computational results for the average diameter of aerosols suspended in air with different moisture content and initial mass concentration were compared with the experimental data. The sensitivity of the computational results to

This article contains information on the occupational external and internal radiation exposure in 2017 for organizations (including NPP) in areas served by the Russian Federal Medical Biological Agency. The parameters of the dose distribution were calculated: mode, median, average, standard deviation, quantile, and coefficient of variation. The distribution of the number of individuals working with

The possibilities of using partial neutron-transport equations, as compared with the classical system of equations, to estimate the temporal behavior of a fast reactor, for which computational studies have been performed on test models of the MET-1000 and MOX-1000 reactors developed as part of the Gen-IV project, are analyzed. The movement of the control rods was modeled as a reason for the appearance

A method of optimizing gas-centrifuge cascade systems for separating binary mixtures of isotopes is proposed. This method makes it possible to determine the optimal parameters of a system with an arbitrary scheme for connecting steps and cascades without performing preliminary calculations of each cascade. This method was used to perform calculations of two-cascade systems with different connection

The outcome of a project to integrate the business-process of computational validation of reactor equipment into a unified information space of an enterprise for the purpose of creating digital doppelgangers of nuclear power facilities is reported. The preparation time required for design documentation was reduced by implementing a program link between the Product Lifecycle Management (PLM) and Simulation

For technical and economic reasons, the technology for extracting platinoids from irradiated fuel is a complex problem. The purpose of the present work was to analyze the content of platinoids in the products of the technological scheme used for reprocessing spent fuel, the most called for methods of extracting platinoids, and the outlook for using platinoids. The problem of extracting platinoids cannot

An advanced version of the BERKUT-U/V2.1 code intended for modeling the behavior of fuel rods with oxide or nitride fuel in standard and emergency operating regimes of fast reactors with liquid-metal coolant is being developed at the Nuclear Safety Institute, Russian Academy of Sciences (IBRAE RAS), as part of the project Next-Generation Codes of Project Proryv (Breakthrough). The present work reports

It is shown that the technological scheme for fabricating uranium dioxide pellets is suitable for fabricating uranium-molybdenum pellets. It permits using the standard powder metallurgy methods to fabricate pellets from uranium-molybdenum powder obtained by thermocentrifugal atomization of ingots of uranium-molybdenum alloy. The proposed technology uses standard equipment operating in easily reproducible

An experimental study was performed of the influence of mixing intensifier-grids on the cooling of a 37-rod electrically heated TVS-2M model with top and bottom reflooding. It is shown that the mixing grids bring about a very small reduction of the maximum temperature of the rods and longer cooling time of the assembly. To cool the TVS-2M model, the starting temperature of the fuel-rod simulators and

The results of using the CONV-3D code to model incompressible fluid flows in round tubes in laminar, transient, and turbulent regimes are presented. The results of modeling with different Reynolds numbers are compared with the Poiseuille parabola and the Blasius formula. It is shown that the code satisfactorily models the flow of an incompressible fluid in laminar, transient, and turbulent regimes

The problems associated with the corrosion of steel in sodium are examined. Equations including the physical constants characterizing mass transfer in the sodium–steel–impurity system are presented. The solution of the system of equations makes it possible to calculate the distribution of the dissolved components and suspensions in sodium flow. The source of the dispersed phase in the coolant fl ow

It is shown that dialysis cells with a sedimentary membrane spontaneously forming from reaction products can be regarded as an effective method for reprocessing the radioactively contaminated liquid media. The studied cell was created on the basis of a commercially produced anisotropic microfiltration element made of fibrous polypropylene. The dialyzer operated in a regime of continuous purging of

The shape and size of the projection of the focal spot of an x-ray tube largely depend on the direction of the beam, which results in a spatial difference of the point spread function (PSF) of the imaging system. A model developed for determining the PSF at an arbitrary point of the radiation field is presented in this article. The input data for the model are the geometric parameters of the system

The characteristic operational features of different flowmeters and devices for measuring the coolant and feedwater flows in the loops of nuclear steam generating facilities (NSGF) currently operating in NPP are analyzed. A new design has been developed for labeled nuclear-magnetic flowmeter-relaxometers with a new flow measuring regime. This regime and other new structural solutions in the new devices

A method was developed for optimizing a cascade with two additional product streams, in which two components of intermediate mass are concentrated simultaneously. The solution of the optimization problem is based on variation of the cuts of partial flows of the cascade steps with large separation factors. A minimum of the total feed stream of the steps with specified concentration of the isotopes is

The status of development work on fuel pins with fast-reactor nitride fuel and a liquid-metal sublayer, which is being considered in Project Breakthrough (Project Proryv) together with fuel pins with a helium sub-layer, is presented. Such fuel pins are shown to have the potential to improve the core characteristics of the advanced high-power reactors BR-1200 and BN-1200. The basic results for the development

The purpose of this work is to develop a migration-dosimetric model of the formation of the irradiation of grassy plants in meadow biogeocenoses under constant radioactive fallout. The model makes it possible to calculate the volumetric activity of radionuclides in the atmospheric surface layer and the intensity of their deposition on the earth surface, the dynamics of the activity of radionuclides

It is shown that there exists an optimal thickness of a rubidium target, dependent on the proton energy at its ingress, for reaching a compromise between the maximum yield of 82Sr and a minimum relative yield of the impurities 83Sr and 85Sr. The optimal irradiation regime and holding time are determined for a target to chemical separation of strontium from it during operation with no accelerator downtime

One of the predicted disruptions in the normal functioning of steam generators in a lead-cooled reactor over a long period of operation is depressurization of the heat-exchange tubes. The most likely tube failure sites are the tube–spacer comb interfacing zones. The oscillatory motion of the tubes in the lead coolant makes it necessary to study the fretting of the tube material. We describe the structural

First-order perturbation theory for the multiplication coeffi cient based on the method of characteristics in the form used in the MCCG3D code is presented. Finite-difference analogs of the perturbation theory formulas are derived using the difference scheme of the MCCG3D code. Test calculations were performed. It is shown that the results obtained by perturbation theory and direct calculations converge

The results of an experimental investigation of the changes occurring in the properties of heat-exchanger material and the thermal conductivity as a result of non-soluble aerosol deposition on heat-exchange surfaces of the passive system removing heat from the containment during severe accidents at NPP are reported. As the investigations showed, the deposited aerosol does not significantly influence

The results of a simulation, performed using the code ATHLET/BIPR-VVER (Russia, Germany), of tests on connecting a single main circulation pump (MCP) unit with three operating units during operation of VVER-1200 at 26% normal power level are presented. A comparison of the calculation and experiment showed the accuracy of the computational model to be satisfactory. Modeling is sufficient from the stand-point

In the course of a controllable thermonuclear fusion reaction the state of the plasma in the reactor must be monitored. Neutron diagnostics can provide some parameters of the plasma in the thermonuclear reactor. In the present work, the neutron diagnostics of the equatorial port of the ITER is checked by means of Monte Carlo modeling of seven external fast-neutron spectrometers based on solid stilbene

A series of works was conducted on determining the coefficient of heat transfer in a bundle of heat-exchange tubes in transverse flow of lead in the base oxygen regime and with oxygen concentration on the saturation line. The object of investigation was an experimental model consisting of a horizontal bundle of six rows of smooth tubes with four tubes per row. The investigation was conducted with sub-

In the decommissioning of the campus B at VNIINM located in a dense residential area in Moscow special attention was devoted to radiation monitoring. For this, the automated radiation monitoring system (ARMS) and mobile-ARMS were involved, the former during decommissioning and the latter during the most critical work; additional measurements were performed in the ventilation channel over 168 days.

The mathematical models implemented in the CABARET-SC1 code are described and the code validation results characterizing its potential in the description of key processes influencing hydrogen propagation in the reactor containment in the course of a severe accident are presented. Agreement with experimental data was achieved by refining the computational grids and adding a radiative heat-transfer model

The design of updated sources of neutrons from the composition of the State Primary Special Standard of units of neutron flux density and neutron fluence for nuclear-physics facilities, GET 51–17, whose upper bound of the reproduction range is raised several-fold as a result of the use of a better neutron generator – NG-10M, is described. The principles and methods of reproducing the neutron flux density

The population dose loads from the radioactive cloud and at residential sites in the contaminated area weredetermined. The dose was determined according to 131–135I, 137Cs, 90Sr, and 60Co. The adjacent uninhabited Dunai Peninsula, Ussuriiskii Zaliv, Primorskii Krai, and China’s Heilongjiang boundary province were considered. The effective dose of external irradiation on Dunai Peninsula was the highest

The results of experiments on the clarification of solution simulators obtainable by means of dynamic crossflow filtration during the reprocessing of mixed uranium-plutonium nitride spent fuel are presented. The experiments were performed using full-scale, dynamic, cross-fl ow filtration stands at the RT-1 radiochemical plant at the Mayak Production Association. It is shown that this method yields

The maximum coolant temperature in the VVR-Ts MAK-2 loop facility for the production of 99Mo was analyzed. The calculations showed that adequate accuracy and temperature 96.3°C are attained using more than 106 grid elements. Taking into account the temperature dependence of the thermal conductivity of the uranium-containing layer increases the maximum temperature in this layer by more than 10%. When

Experiments performed at the Mayak Production Assiciation to determine the 232U content in spent BN-600 fuel are analyzed. Calculations show that to within the limits of error the concentration largely agrees with the measured value, which makes it possible to use the calculations for a preliminary assessment of the 232U content in batches of uranium regenerated from reprocessed spent BN-600 FA.

The design of the TUK-109T large-size container developed at the All-Russia Research Institute of Experimental Physics (VNIIEF) for transporting ampuls with bundles of spent fuel pins is described. The results of full-scale tests and three-dimensional simulation modeling for strength validation for mechanical actions occurring under normal operating conditions and during emergencies are presented.

The operating time of the IBR-2 reactor depends on the fuel life. Currently, an IBR-2 run is formed at the cost of adding fresh FAs into the core without any reshuffling of the FA. In spite of its technological simplicity, this approach results in suboptimal fuel use because of high burnup non-uniformity. In the present work we propose optimizing a reactor fuel run by reshuffling FA during the run

The circulation flow in a centrifuge during enrichment of isotopic mixtures of heavy gases is determined. Nickel tetraphosphine Ni(PF3)4 was used as the working substance to study the hydraulic and separative characteristics of a centrifuge. The relative circulation parameter m characterizing the efficiency of the multiplication of the primary effect is determined by comparing the computed dependences

The results of an analysis of the thermal impact of the circulating cooling water discharged after cooling equipment in the Kalinin NPP on the thermic regime of the cooling reservoir and the climate in the littoral areas are presented. The impact was evaluated by comparing the hydrometeorological characteristics before the commissioning of the nuclear plant (1971–1983) and during its operation at full

The exportation of fast reactors under an international nuclear weapons non-proliferation regime is discussed. Russian sodium fast-reactor technology has been successfully demonstrated and is in the commercialization stage. Fast reactors with lead as coolant are being developed in Project Breakthrough. In this connection, the possibility of exporting fast reactors becomes logical. The main criterion

The trajectory of a radioactive cloud formed above the Dunai Peninsula, Ussuriiskii Zaliv, Primorskii Krai, and the border area of China as a result of a nuclear accident in Bukhta Chazma in 1985 was reconstructed. The population–cloud contact time and the radioactive fallout density of the primary dose-forming radionuclides are estimated and the obtained results are compared with the admissible norms

The SKP-KhOT system for measuring subcriticality, making it possible to determine Keff of jackets with spent FA VVER-1000 during normal operation as well as design basis and beyond-design basis accidents, has been installed in the KhOT-1 storage facility at the Mining and Chemical Combine. The results of its tests have been recognized as positive; the design basis subcriticality of the studied jackets

The automated system ASCRO developed and adopted in the nuclear industry for monitoring radiation conditions and on-site monitoring of subsoil status is continually improving, and the Rosatom State Corporation is continually expanding the sphere of activity of these systems. In the present article, the experience gained in the implementation of on-site monitoring of subsoil status in 2017 and the principles

The influence of the active-element characteristics on the efficiency of a cadmium-vapor laser pumped by uranium fission fragments was studied experimentally. The 441.6 nm laser radiation of the cadmium ion was studied. An aluminum tube with diameter ~15 mm and an inner coating of U3O8 with thickness 3 mg/cm2 served as the active element. The neutron source was the BARS-6 pulsed, fast, aperiodic, self-extinguishing

An approach to developing the NPP system with the lowest integral risk determined according to the entire life cycle and the conjugate infrastructure is studied. The search for the optimal power series of reactors for the developing NPP system is formalized and presented as a multicriterion optimization problem: reduction of harm from various risk factors and construction cost for the specified system

The results of the verification of a model of the IVG.1M reactor based on experiments performed in 1990 and 2017 are reported. Startups of the reactor which are associated with its emergence into a critical state and measured values of the power, neutron flux density, and efficiency of the CPS [control and protection system] components were chosen for verification The isotopic composition of the fuel

Dinitrogen oxide N2O (nitrogen hemioxide) is one of the harmful components of the off-gases during the reprocessing of spent nitride fuel. It enters the gas phase during the dissolution of nitride fuel in nitric acid and denitration of high-activity raffinate or the bottom solution from the evaporation of intermediate-level wastes. The preferred method of neutralizing it is high-temperature catalytic

It is proposed that the cost of production of titanium sponge can be lowered by replacing the expensive and environmentally hazardous Mg-thermal conversion process by hydrogen reduction of titanium tetrachloride. The Kroll process, which is mainly used to produce titanium, is costly, which determines the high cost of titanium sponge. The reprocessing of titanium sponge into ingots requires large amounts

To study the characteristics of the mass transfer of noncondensable gases in the primary loop of the nuclear icebreaker reactors, models of the core and the up-core space were developed using the Relap5 (USA) and Fluent (USA) codes and modeling of interphase mass transfer and transport of the gas phase by the water coolant was performed on these sections. Spatial non-uniformity of the content of undissolved

An alert indicating the formation of salt deposits in the pipelines of oil and gas production complexes reduces the financial losses associated with the removal of these deposits and the loss of production. A method of taking into account the presence of the native radionuclide 232Th and its decay product 208Tl in the deposits is proposed for performing radiation diagnostics of pipelines. The appearance

The purpose of this work is to compare industrial trials of modernized intermediate SPP-500-1 moisture separators-heaters of the K-500-65/3000 turbines in the No. 4 unit of the Leningrad NPP and the No. 1 unit of the Smolensk NPP. It was found that the distribution of the separated moisture along the perimeter and height of the steam space at the egress from the separation units is uniform in both