Explosion-resistance of the cylindrical part of a fast-reactor vessel

All-Russia Scientific-Research Institute of Electrophysical Apparatus. Special Office of Machine Design. Institute of High Temperatures, Russian Academy of Sciences. Translated from Atomnaya énergiya, Vol. 79, No. 3, pp. 178–188, September, 1995.     

Electronuclear Systems – a New Generation of Nuclear Power Systems

The possibility of using electronuclear systems as a new generation of safe nuclear power systems is examined. Since the reliability of the linear accelerator is a basic safety element of an electronuclear system, novel methods for increasing accelerator reliability, which were developed at the Institute of Theoretical and Experimental Physics, are proposed.The special features of electronuclear systems as compared with conventional critical reactors are demonstrated by comparing the characteristics of the TVR research reactor at the Institute for Theoretical and Experimental Physics to those of an electronuclear neutron generator based on the TVR and the ISTRA-36 linear proton accelerator. It is shown that the generator is much safer than the TVR reactor.     

Linear electron accelerators for industry and medicine

Linear accelerators are described together with accelerator systems based on them, which have been designed and produced in the linear-accelerator and cyclotron division at the D. V. Efremov Fundamental Electron Applications Research Institute. Brief information is given on future developments in resonant linear accelerators and systems based on them. D. V. Efremov Fundamental Electron Applications Research Institute. Translated from Atomnaya énergiya, Vol. 87, No. 2, pp. 145–151, August, 1999.     

Mass spectrometry,with an inductively coupled plasma,of inorganic trace impurities in ultrapure water

Conclusions The final result of investigations of the mass spectrometer with an inductively coupled plasma for analysis of inorganic trace impurities in ultrapure water was the development of instrumental-methodological techniques for increasing the efficiency and reliability of the recording process. This made it possible to choose internal calibration standards and criteria for changing the calibration coefficients. The research instrumentation complex, developed at the All-Union Scientific-Research Institute of Technical and Physical Apparatus, is suitable for quantitative analysis of the elemental content of trace impurities in water with the indicated analytic characteristics for the relative method of measurement according to internal calibration standards. A further improvement of the research apparatus is lower transmission losses which result from the effect of the edge fields according to the constant and variable components, with the aid of a nonuniform standing wave of voltage applied to the mass analyzer as well as the detection limit obtained with the aid of an ion-trap-type detector. The preliminary results show that these techniques make it possible to improve transmission by up to a factor of 30 and to work with a resolution of 100M, as well as to decrease the detection limits by a factor of 10. In conclusion, we thank S. S. Grazhulen and Yu. I. Popandopulo (Institute of Applied and Theoretical Mechanics of the Russian Academy of Sciences) for collaboration and assistance in performing the control measurements of the impurity content in the samples on the VG Elemental PQ2 mass spectrometer with an inductively coupled plasma, S. G. Galaktionov and A. L. Makarov (All Union Scientific-Research Institute of Chemical Technology) for providing the samples, and A. A. Sysoev (Moscow Engineering Institute) for a helpful discussion of the results. All-Union Scientific-Research Institute of Technical and Physical Apparatus. Translated from Atomnaya énergiya, Vol. 77, No. 2, pp. 134–140, August, 1994.     

Experimental Investigation of Models of a Cascade Blanket in an Electronuclear System

Using in an electronuclear system a two-section blanket with unilateral neutron coupling of the sections (cascade-type blanket) can decrease substantially the power requirements for the accelerator. Theoretical work confirms this supposition, but there are no experimental data in this field. An experimental investigation of cascade-type blankets is planned at the All-Russia Scientific-Research Institute of Experimental Physics. The results of a computational substantiation of models of a cascade blanket (primarily with a central section consisting of ²³⁷Np), which are suitable for performing experiments, are presented. The models chosen for the blanket are deeply subcritical (k _eff = 0.5–0.6) and contain a relatively small amount of fissioning materials. These models satisfy the nuclear-safety requirements and at the same time ensure that the experiments yield adequate information.     

A cyclotron with a spatially varying magnetic field

This article is devoted to the design of a cyclotron with a spatially varying magnetic field. The basic conclusions of the linear theory of motion of charged particles in a magnetic field of periodic radial and azimuthal structure are given. The theoretical and experimental results of the study of nonlinear resonance close to the center of the accelerator are presented. Formulas are obtained for the calculation of required magnetic field configurations. Methods of shimming, measurement, and stabilization of the magnetic field are suggested. An accelerator designed with pole faces of diameter 120 cm was used for modeling the ion phase motion and for investigating spatial stability. Deuterons were accelerated to an energy of 13 Mev at an accelerating voltage of 5 kv.A brief account of the starting up of this accelerator appeared in the journal Atomnaya Energiya6, 6, 657 (1959). [Original Russian pagination. See. C. B. translation]The authors highly appreciate the great amount of work and effort on the part of the personnel of the experimental shop, designing office, electronic and electrical departments of the Nuclear Problems Laboratory of the Joint Institute of Nuclear Studies. The authors are deeply grateful to these personnel and to their chiefs K. A. Baicher, N. I. Frolov, M. F. Shul'ga, F. V. Chumakov for their aid, valuable discussions, and suggestions in solving many technical problems. The authors express their gratitude to D. I. Blokhintsev, D. V. Efremov, K. N. Meshcheryakov, V. N. Sergienko for constant interest and assistance, which greatly facilitated the work, to E. G. Komar, I. F. Malyshev, L. N. Fedulov for constructing and preparing the chamber and the magnet of the accelerator, to A. V. Chestnyi for help during the first stage of setting up the technical problem.     

Experimental Confirmation of the Concept of Two-Section Cascade-Type Blankets

In the last ten years, Russia and other countries have been showing a great deal of interest in two-section blanket reactors with unilateral neutron coupling of the sections (cascade-type blankets). These setups are intended to operate in power and transmutation electronuclear facilities, for which they permit decreasing substantially the required power of the proton accelerator. Theoretical and design works have been done on cascade-type blankets, but until very recently there were no experimental works.The results of the first experiment of this type, performed at the All-Russia Scientific-Research Institute of Experimental Physics, on compact deeply subcritical uranium–neptunium assemblies are presented. The experiment has confirmed the theoretical conclusion that cascade blankets have positive properties and ²³⁷Np is effective as a means for achieving unilateral coupling of the sections.     

Conditions for effective utilization of the electronuclear blanket system as a neutron source

The efficiency of an intermediate-energy electronuclear setup with a blanket as an alternative source of neutrons is discussed on the basis of experience in designing the electronuclear neutron generator at the Institute of Theoretical and Experimental Physics. A classification of electronuclear setups is introduced. The factors determining the efficiency of the driver-target-multiplying blanket scheme at low and intermediate driver energies are examined. To obtain high neutron fluxes, the possibility of compensating an inadequate driver current by decreasing the subcriticality store is examined and the conditions for realizing such a possibility while preserving the fundamental requirement of nuclear safety are formulated. The concept of the criterion of dynamical safety, in contrast to the criterion of static safety ordinarily assumed for subcritical systems, is introduced. A program of precision investigations for studying operating regimes of a blanket under conditions of a low store of subcriticality is formulated on the basis of the criterion of dynamical safety. The results of an implementation of this program are important for the assessment of the technological possibility and desirability of replacing research reactors with subcritical setups based on an accelerator. 2 figures, 6 references. State Science Center of the Russian Federation-Institute of Theoretical and Experimental Physics. Translated from Atomnaya énergiya, Vol. 87, No. 4, pp. 255–262, October, 1999.     

The elder of Russian academicians

The creative journey of Nikolai Antonovich Dollezhal’—outstanding designer, scientist, academician, one of the founders of reactor construction in our country, twice Hero of Socialist Labor, Laureate of the Lenin Prize and five State Prizes—is described. N. A. Dollezhal’ was the director of the Institute of Chemical Machine Building in 1942–1953, director of NII-8 since 1953, and director of the Scientific-Research and Design Institute of Power Engineering since 1976. N. A. Dollezhal’ was the principal designer of the reactor for the first nuclear power plant in the world, started up in Obnisk in 1954, the principal designer of the first industrial and research reactors and the first reactors for nuclear power plants and nuclear-powered submarines built in our country. The 1000 MW RBMK uranium-graphite channel reactor was developed under the leadership of the principal designer N.A. Dollezhal’. Scientific-Research and Design Institute of Power Engineering. Translated from Atomnaya énergiya, Vol. 86, No. 4, pp. 302–310, April, 1999.     

Experimental Electronuclear Setup at the Institute of Theoretical and Experimental Physics

The purpose and current construction status, at the Institute of Theoretical and Experimental Physics, of an experimental electronuclear setup, combining a pulsed proton linear accelerator (36 MeV, 0.5 mA) and a subcritical blanket thermal-power assembly 100 kW, are discussed. The main equipment is already available or is being built in industry. The setup can be used to investigate the dynamics of the interaction of a linac–driver and a subcritical reactor and problems concerning the accelerator–driver and the target–blanket assembly. The proton beams and neutron fluxes will be used for applied purposes. In the future it will be possible to increase substantially the current and energy of the proton beam.     

Apparatus for dynamic monitoring of the size,shape, and density of fuel pellets

All-Union Scientific-Research Institute of Technical and Physical Apparatus. Translated from Atomnaya énergiya, Vol. 76, No. 1, pp. 61–65, January, 1994.     

The use of monodirectional neutron sources for the investigation of shielding (B-2 apparatus in a BR-5 reactor)

The report describes the B-2 apparatus, installed in a BR-5 fast reactor, for investigating the passage of neutrons through various shielding materials. It is shown that the monodirectional neutron disc source used in this apparatus makes it possible to obtain detailed information on the spatial-energy and angular distributions of the neutrons in the shielding. The effect of the angular distribution of the radiation leaving the source on the attenuation factor of this radiation in shielding was also investigated.In conclusion I would like to express my sincere thanks to A. I. Leipunskii for valuable advice during the formulation of the scheme of investigations concerning the passage of neutrons in different media from monodirectional sources, and I. I. Bondarenko, V. V. Orlov, V. I. Kukhtevich, Yu. A. Kazanskii, B. I. Sinitsyn, E. S. Matusevich, B. P. Shemetenko, Sh. S. Nikolaishvili, V. P. Mashkovich, and A. A. Abagyan for discussing the results of this work; and, finally, D. S. Pinkhasik 'and N. N. Aristarkhov for considerable help in making the B-2 apparatus.     

Expanded 233U Breeding in the Heavy-Water Blanket of an Electronuclear System

Comparative investigations are performed of the neutron-physical characteristics and their variations during burnup for two types of fuel Th–U and U–Pu with heavy- and light-water lattices. Analysis of the results gives the basic parameters of the electronuclear system operating in a thorium–uranium fuel cycle. It is shown that an external neutron source (accelerator + target) makes it possible to switch to the thorium–uranium fuel cycle with expanded ²³³U breeding without using fissioning uranium or plutonium isotopes. There are grounds for believing that with a higher accelerator current it is possible to achieve a regime where the heavy-water blanket can be replenished only with thorium with no ²³³U.     

Characteristics of electronuclear targets containing water

Conclusions The replacement of liquid-metal lead or sodium coolant with water has virtually no effect on the intensity of the neutron flux in the blanket of an electronuclear installation and the formation of²³⁹Pu nuclei. The accumulation of²³⁹Pu nuclei is accompanied by a rapid growth of the heat release in the target and a decrease of the production rate. On account of the block effect, the heterogeneity of the target results in an appreciable increase of the neutron flux and breeding. At the same time, when a hydrogen-containing target is used, the heat release increases considerably. Taking into account the chemical bond in the water molecules and the energy dependence of the neutron cross sections in the thermal region has virtually no effect on the characteristics of an electronuclear installation, and they can be neglected in calculations. Joint Institute of Nuclear Research. Translated from Atomnaya énergiya, Vol. 77, No. 6, pp. 419–424, December, 1994.     

Fuel-element inspection stand in the cooling pond of an atomic power plant

V. I. Lenin Scientific-Research Institute of Atomic Reactors. Ignalina Atomic Power Plant. Scientific-Research and Design Institute of Electrical Engineering. Translated from Atomnaya Énergiya, Vol. 72, No. 1, pp. 22–25, January, 1992.     

Thermohydraulic characteristics of the condenser in the natural-circulation loop of an MTR modular heavy-water reactor

Scientific Design Department, I. I. Polzunov Central Scientific-Research Institute for the Planning and Design of Boilers and Turbines. St. Petersburg Technical University. Institute of Theoretical and Experimental Physics. Translated from Atomnaya Énergiya, Vol. 72, No. 2, pp. 136–142, February, 1992.     

Thermostable corona counters for slow neutrons

A substantiation is given of the characteristic features of the construction and gas fill of high-efficiency slow-neutron corona counters operating at temperatures up to 250–300°C. The basic operating parameters of the counters are presented. 1 figure, 3 references. All-Russia Scientific-Research Institute of Thermophysical Apparatus. Translated from Atomnaya énergiya, Vol. 87. No. 3, pp. 219–222, September, 1999.     

Research and Development of Minor Actinide-containing Fuel and Target in a Future Integrated Closed Cycle System

Research and development of minor actinide-containing fuels and targets, i.e., (Pu,Am)O₂–MgO, (Pu,Np)O₂–MgO, (U,Pu,Np)O₂, (U,Pu,Np)N and (Pu,Np,Zr)N, for use in a future integrated closed cycle system that includes fast reactor and accelerator driven sub-critical system is underway. The present statuses of fabrication test and property measurements are given. Design concept of the oxide target is described in detail together with a screening of the support material. A new apparatus for the measurement of mechanical properties at the elevated temperature is installed for use in evaluating the fuel-cladding mechanical interaction. Development histories with future prospects of two types of Np-containing fuels for the fast reactor are mentioned. Preliminary test results for a new nitride target for the accelerator driven sub-critical system are given. Finally, an irradiation test plan in the experimental fast reactor JOYO is briefly described.     

The absorption of deuterium by carbon-based facing materials on components in contact with the plasma in a thermonuclear reactor

Conclusions The conditions have been proposed for performing modeling experiments making it possible to predict the accumulation of hydrogen isotopes in carbon materials which are in contact with a tokamak plasma acting as a source of particles having a flux density of between 3×10¹⁶ and 3×10¹⁹ cm⁻²·sec⁻¹. By analyzing the reemission fluxes formed in the stopping zone of the particles implanted from the plasma it is suggested that the action of the plasma as regards the sorption of hydrogen is identical to that of annealing the material in an atmosphere of hydrogen isotopes at a pressure of 1–10³ Pa and a temperature of 1200–1700 K. The quantity of absorbed deuterium in POCO, UAM, RGT-B, and USB increases as the temperature is lowered and the pressure is raised (1500 K, 0.66 Pa→1200 K, 133 Pa). As regards their sorption of deuterium, POCO, UAM, and RGT behave similarly. There is a tendency for the sorption capacity of materials doped with boron to be reduced. In a class of itself is the isotropic material USB, whose sorption capacity is a factor of 10–100 lower than that of undoped graphite. The introduction into these materials of radiation-induced defects (T=300 K) by means of ion irradiation in the range 0.1–1 dpa results in a continuous rise in the deuterium sorption capacity by a factor of 10–100 (up to 10⁻² atomic fraction). The USB graphite demonstrates record low increments in the sorption capacity. In the fluence range identical to 1–10 dpa the sorption capacity of carbon materials for hydrogen is almost constant. The process of the sorption of hydrogen isotopes can be described as the filling of two ensembles of traps, deep traps which are difficult to access and readily accessible Langmuir traps. In the RGT-B materials containing 0.1% of boron, the traps introduced by irradiation with 300-keV neon ions vanish on annealing in a vacuum (T=1800 K, t=1 min). Institute of Physical Chemistry, Russian Academy of Sciences. SINTEZ Scientific and Technical Center, Scientific-Research Institute of Electrophysical Apparatus. Graphite Scientific-Research Institute. National Scientific Center, Kharkov Physicotechnical Institute. Translated from Atomnaya énergiya, Vol. 82, No. 6, pp. 448–464, June, 1997.