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Vol 124, No 4 (2018)

Article

Investigation of Transient Xenon Processes in VVER-1200 at the Novovoronezh NPP

Aver’yanova S.P., Vokhmyanina N.S., Zlobin D.A., Filimonov P.E., Povarov V.P.

Abstract

The results of experimental studies of the integral and spatial transient xenon processes in the No. 6 unit of the Novovoronezh NPP with VVER-1200 are presented. An unconventional method of measurement was tested in the study of integral processes: the course of the xenon process was recorded as the change in the critical concentration of boric acid in the reactor simultaneously with a calculation of the concentration in real-time. The spatial transient processes were studied for the example of axial and diametral free xenon oscillations of energy release in the core.

Atomic Energy. 2018;124(4):215-220
pages 215-220 views

RBMK Uranium-Erbium Fuel

Fedosov A.M.

Abstract

The history of the development and adoption of erbium fuel in RBMK is described. Research performed at the end of the 1980s – beginning of 1990s led to the conclusion that the optimal method of decreasing the steam coefficient of reactivity in RBMK is to add a consumable absorber – erbium. Computational and experimental work on the safety validation of the new fuel made it possible to adopt this fuel first in RBMK-1500 and then in RBMK-1000. The use of uranium-erbium fuel in RBMK made it possible to increase reactor safety, provide the requisite conditions for modernizing control rods, reduce the acuteness of the problem of storing spent fuel, and improve the economic indices of the fuel cycle. Considering the heightened interest in the use of erbium as a consumable absorber in VVER and some other reactors, the experience gained in developing and operating uranium-erbium fuel for RBMK could be helpful.

Atomic Energy. 2018;124(4):221-226
pages 221-226 views

Dynamics of Power Pulses in a Research Reactor with Neptunium Nuclear Fuel

Shabalin E.P., Rzyanin M.V.

Abstract

The current trend in neutron-aided scientific research presupposes the development of new high-intensity pulsed sources. One variant of such an installation could be a pulsed reactor with a fissile-isotope core – 237Np. The present work is devoted to a study of the dynamics of power pulses of a neptunium reactor taking account of fast temperature feedback during pulse buildup. The problem is reduced to a simple model of a single frequency oscillator combined with the equation of single point kinetics of a reactor neglecting delayed neutrons. It is shown that on the basis of such an approximation, owing to feedback on the temperature of a fuel element the estimated energy of accidental power pulses decreases by almost a factor of 10 compared with a calculation neglecting fast feedback.

Atomic Energy. 2018;124(4):227-231
pages 227-231 views

SAFR/V1 (EVKLID/V2 Integral Code Module) Aided Simulation of Melt Movement Along the Surface of a Fuel Element in a Fast Reactor During a Serious Accident

Usov E.V., Butov A.A., Chukhno V.I., Klimonov I.A., Kudashov I.G., Zhdanov V.S., Pribaturin N.A., Mosunova N.A., Strizhov V.F.

Abstract

The basic approaches used in the SAFR/V1 module of the integral code EVKLID/V2 to simulate the movement of the melt formed upon melting of fuel elements are presented. The system of mass, energy, and momentum conservation equations used to simulate the movement of melt is presented. Special attention is devoted to methods of numerical approximation of the equations as well as to the solution of problems involving smearing of the solution at the melt boundary. The realized methods of stimulating the motion of melt have been verified on the basis of tests with known analytical solutions.

Atomic Energy. 2018;124(4):232-237
pages 232-237 views

Heat-Exchange in One-Phase Liquid-Metal Flows: Databank (Temperature Distribution in Circular Pipes)

Kirillov P.L.

Abstract

In order to develop accurate methods of calculating heat-exchange in forced channel flows, it is necessary to have knowledge about the temperature distribution over the cross section in differ layers of the flow. For ordinary liquids (gas, water, where the Prandtl number Pr ~ 1), such measurements are difficult to perform because of the small thickness of the boundary layer. The problem simplifies for liquid metals, where Pr << 1. This article contains the format of the data as well as an analysis of the primary data from 37 home and foreign works (mercury, sodium-potassium alloy, sodium, lithium, lead-bismuth alloy). The data are presented in electronic form.

Atomic Energy. 2018;124(4):238-243
pages 238-243 views

Nuclear Rocket Motors: Development Status and Application Prospects

Koroteev A.S., Akimov V.N., Arkhangel’skii N.I., Kuvshinova E.Y., Muzychenko E.I.

Abstract

The possibility and expediency of using nuclear rocket motors at the present stage of development of rocketspace technology as part of conventional and advanced space means, including the upper stages of carrier rockets and acceleration blocks, reusable interorbital tugs, and a motor assembly of the piloted Martian expedition complex are discussed. It is shown that because of high cost it is not expedient to use NRM in single-use booster blocks and multi-use tugs for transport operations in near-Earth space, since the specific cost of delivering a useful load into high working orbits increases by a factor of 1.5 or more as compared with transport means based on oxygen-hydrogen rocket motors. At the same time, their use for the Martian expedition complex makes it possible to improve considerably the design characteristics of the complex (starting mass and expedition duration) as compared with non-nuclear motor systems.

Atomic Energy. 2018;124(4):244-250
pages 244-250 views

Measurement of the Kinematic Viscosity of Melted Mixtures of Sodium, Lithium, and Beryllium Fluorides and the Effect of the Eutectic Additive Cerium Trifluoride on the Viscosity

Merzlyakov A.V., Ignat’ev V.V.

Abstract

Experimental data on the kinematic viscosity and liquidus temperature of certain fused mixtures of sodium, lithium, and beryllium fluorides were obtained, by the method of damping of torsional oscillations of a cylinder with the experimental melt, in validation of the concept of molten-salt incinerator reactors for incinerating transuranium elements from spent nuclear fuel from light-water reactors. The measurements were conducted from the liquidus temperature to 800°C. The effect of the addition of cerium trifluoride on the viscosity of the eutectic melt 58NaF–15LiF–27BeF2 was studied. It was shown that the additive appreciably reduces the viscosity at low temperature and also lowers the liquidus temperature. The parameters characterizing the temperature dependence of viscosity were determined for the experimental melts.

Atomic Energy. 2018;124(4):251-254
pages 251-254 views

Accounting for Environmental Aspects in Water-Chemistry Optimization of the Second Loop of NPP with VVER

Gavrilov A.V., Prokhorov N.A., Kritskii V.G.

Abstract

A problem in operating NPP with VVER is that waste solutions containing ethanolamine and ammonia from regeneration of ion-exchange filters from the second loop must be processed. The amount of ammonia in the regeneration solutions is equal to 85% of the total amount of the contaminating substances. The water chemistry regime of the second loop without ammonia or with ammonia replaced by dimethylamine is examined. It is shown that the use of dimethylamine makes it possible to increase the duration of the filtration cycle for ion-exchange filters of the purification systems, decrease the concentration of products of corrosion, reduce the environmental impact, and simplify the waste water purification technology.

Atomic Energy. 2018;124(4):255-260
pages 255-260 views

Measurement of 99Mo Yield in 100Mo(p, x) with 30 MeV Proton Irradiation of Multicomponent Submicron Particles

Artyukhov A.A., Zagryadskii V.A., Kravets Y.M., Kuznetsova T.M., Men’shikov L.I., Ryzhkov A.V., Udalova T.A., Chuvilin D.Y.

Abstract

The radionuclide 99Mo was produced and separated in the process of irradiating powdered mixtures of molybdenum compounds and buffer particles by 30 MeV protons. The separation is based on the Szilard–Chalmers effect wherein 99Mo recoil particles are fixed in inert buffer particles. Two types of targets were investigated by using mixtures: soluble molybdenum compound–insoluble buffer and insoluble molybdenum compound–soluble buffer. 99Mo yield equal to 20% with enrichment coefficient 18.3 was obtained by using a target consisting of a mixture of submicron 100MoO3 and Al2O3 particles; the 99Mo yield was equal to 20% and the enrichment coefficient 18.3. For a target with the composition 100MoS2 + KCl, making it possible to separate 99Mo recoil atoms directly into solution, the 99Mo yield was equal to 8.7% and the enrichment coefficient 30.7.

Atomic Energy. 2018;124(4):261-265
pages 261-265 views

AEROSOL-LM/Na Aided Simulation of Fission Product Production and Transport in the First Loop of a Fast Reactor

Filippov M.F., Kolobaeva P.V., Mosunova N.A., Sorokin A.A.

Abstract

The structure of models and a description of the AEROSOL-LM/Na module, which is intended for simulating the transport and behavior of impurities sodium coolant and fission product aerosols in a normal operating regime of a reactor and in beyond design basis accidents, are presented. The characteristic features of the module are: accounting for the basic behavior of dissolved impurities in the sodium coolant, simulation of the dynamics of multi-component and polydisperse aerosols in the gas cavity of the first loop of the reactor, functional coupling with other modules of the code (thermal hydraulic and fuel), and simulation of the behavior of fission products as a function of the running state of the reactor installation.

Atomic Energy. 2018;124(4):266-271
pages 266-271 views

Tritium Module for Calculating the Behavior of Tritium in a Loop of a Reactor Installation with Sodium Coolant

Il’yasova O.K., Nazarova S.N., Sorokin A.A.

Abstract

A description of the models and the results of tests of the Tritium module, which is intended for modeling the transport of tritium in the loops of fast reactors, are presented. The characteristics features of the module are alienability, functional relation with other modules of the code, and calculation of model coefficients as a function of the temperature of the coolant and surface of the loops. The module makes it possible to perform calculations of the behavior of tritium, including transport along loops, penetrability through the channel walls, run-off in a cold trap, and flow through leaks in the reactor installation.

Atomic Energy. 2018;124(4):272-278
pages 272-278 views

Calculation of the Present Value of Separative Work for Uranium Isotopes

Pavlov Y.G., Ul’yanin Y.A., Semenov E.V., Kharitonov V.V.

Abstract

An economics-mathematical model for performing analytical calculations of the present value of separative work for uranium isotopes in a separation plant currently being designed using gas centrifuge technology is examined. Analytical expressions are obtained for the present value of the separative work, the internal rate of return, and the payback period of the separation plant as a function of its main engineering and economics parameters – productivity (capacity), capital investment, and operating expenses. Calculations of these criteria for investment efficiency are presented for a wide range of initial data. It is shown that the calculation of the present value of separative work must be performed in a complex with other investment efficiency criteria in order to determine their optimal combination.

Atomic Energy. 2018;124(4):279-286
pages 279-286 views