Soviet Atomic Energy Vol. 46, No. 5

Body: Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 31x Iiiissian Original Vol. 46, No. 5, May, 1979. , November, 1979' . SATEAZ 46(5) 351-426 (1979) ATOMIC ENERGY ? ATOMHAFI 3HEP11#111 (ATOMNAYA gNERGIYA) TRANSLATED FROM RUSSIAN \ CONSULTANTS BUREAU, NEW YORK - Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 ' Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 SOVIET Energiya, a publication of the Academy of Sciences of the USSR. Soviet Atomic Energy is a cover7to-coir translation of Atomnaya ATOMIC An agreement with the Copyright Agency of the USSR (VAAP) makes available both advance copies of the Russian journal and original glossy photographs and artwork. This serves to decrease the necessary time lag between publication of the original and ENERGY publication of the translation and-helps to improve-the quality of the latter. The _translation began with the first issue,of the Russian journal. ? Soviet Atomic Energy is abstracted Or in- dexed in Applied Mechanics Reviews, Chem- ical Abstracts, Engineering Index, INSPEC? Physics Abstracts and Electrical and Elec. tronics Abstracts, Current Contents, and Nuclear Science Abstracts Editorial Board of Atomnaya Energiya: Editor: 0. D. Kazachkovskii Associate Editors: N. A. Vlasov and N. N. Ponomarev-Stepnoi I. N. Golovin V. I. ll'ichey V. E. lvanov V. F. Kalinin P. L. Kirilov Yu. I. Koryakin A. K. Krasin E(V. Kulov B. N. Laskorin V. V. Matveev ' I. D. Morokhov A. A. Naumov A. S. Nikiforov - A. S. Shtan' , B. A. Sidorenko M. F. Troyanov ? E. I. Vorobiev Copyright C) 1979, Plenum Publishing Corporation. Soviet Atomic Energy partici- pates in the program of Copyright Clearance Center, Inc. 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Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 SOVIET ATOMIC ENERGY A translation of Atomnaya tnergiya November, 1979 Volume 46, Number 5 May, 1979 CONTENTS COMECON -30 YEARS Engl./Russ. The Peaceful Atom in the Socialist Countries - A. F. Panasenkov 351 299 ARTICLES Safety Problems of Sodium-Water Steam Generators and Their Solution in the USSR - V. M. Poplavskii, Yu. E. Bagdasarov, F. A. Kozlov, L. A. Kochetkov, and V. F. Titov 361 311 Accuracy of Neutron Field Regulation in Nuclear Reactors - L. P. 131,ekhanov 366 316 An Investigation of the Dynamics of Nuclear Power Facilities upon Deterioration of Heat Exchange - G. G. Grebenyuk and M. Fat Dorri 370 320 Radiational Swelling of Two-Phase Austenitic- Ferritic Stainless Steels - Yu. A. Utldn, V. A. Nikolaev, 0. N. Zhukov, I. A. Kuz'mina, and L. G. Egorov 375 324 Electron-Spectroscopic Analysis of Neutron-Irradiated Pyrographite - A. N. Baranov, A. G. Zelenkov, V. M. Kulakov, V. P. Smilga, Yu. A. Teterin, V. I. Karpukhin, Yu. P. Tumanov, and 0. K. Chugunov 379 329 Mathematical Simulation of Processes of Extraction Processing of Nuclear Fuel Fluxes. 6. Effect of Flux Oscillations on the Accumulation of Plutonium - A. M. Rozen and M. Ya. Zervenskil 383 333 Linear Electron Accelerator for 1-mA Average Current - G. L. Fursov, V. M. Grizhko, I. A. Grishaev, B. G. Safronov, L. K. Myakushko, V. S. Balagura, V. I. Beloglazov, F. S. Gorokhovatskii, A. I. Martynov, and A. P. Rudenko 387 336 LETTERS TO THE EDITOR Calculation of Gamma Power of Hot Circuits with Nonfissionable Materials - N. I. Rybldn, E. S. Stariznyi, and A. ICh. Breger 392 341 Performance of an Irradiation Loop Containing Nonfissile Material - N. I. Rybkin, A. Kh. Breger, E. S. Stariznii, and N. P. Sirkus 394 342 Self-Absorption Factor of y Radiation in Fuel Assemblies - V. A. Voronina, Yu. N. Kazachenkov, and V. D. Simonov 396 344 Temperature Field at the Surface of the Peripheral Assembly Fuel Elements in a Nuclear Reactor with a Liquid-Metal Coolant - B. P. Shulyndin 399 347 Activation Component of the Response of a Self-Powered Neutron Detector to Thermal and Epithermal Neutrons - 0. Erben 402 349 - Number of K-E mission Photons Generated by Monoenergetic Electrons and 13 Particles - F. P. Teplov, V. P. Sytin, and A. I. Melovat-skaya 406 352 Viscosities of Molten Mixtures of Uranium Tetrafluoride with Alkali Fluorides - V. N. Desyatnik, A. I. Nechaev, and Yu. F. Chervinskii 408 354 Determination of Fuel Burnup in VVER-440 Assemblies with an "Aragonit" Radiation Meter - 0. A. Miller, L. I. Golubev, G. A. Kulakov, and Yu. V. Efremov 410 356 Minimization of Energy Distribution Inhomogeneities in a Nuclear Reactor - V. V. Pobedin and V. D. Simonov 411 357 Formation of Hydrogen in the Radiolysis of Water Vapor - B. G. Dzantiev, A. N. Ermakov, and V. N. Popov 414 359 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 CONTENTS 0Ill J INFORMATION The 45th Meeting of the Scientific Council of the Joint Institute for Nuclear Research (continued.) Engl./Russ. ? V. G. Sandukovskii. 416 361 CONFERENCES AND SEMINARS Conference on the Fifth Anniversary of the Commissioning of Leningrad Nuclear Power Station ? A. P. Sirotkin 421 364 All-Union Conference on Ionizing-Radiation Protection of Nuclear Engineering Facilities ? V. P. Mashkovich 422 365 Soviet? French Seminar on Safety of Atomic Power Plants with Water-Moderated?Water-Cooled Reactors ? A. N. Isaev 424 366 Meeting of Group of IAEA Advisers on Atomic Power Plant Safety ? 0. M. Kovalevich . 426 368 The Russian press date (podpisano k pechati) of this issue was 4/21/1979. Publication therefore did not occur prior to this date, but must be assumed to have taken place reasonably soon thereafter. Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 COMECON ?30 YEARS THE\ PEACEFUL ATOM IN THE SOCIALIST COUNTRIES A. F. Panasenkov UDC 621.039(103) In 1979 the Council for Mutual Economic Aid (COMECON) completed its 30th year of activity 'as the first international economic, scientific, and technical organization of socialist governments. In January 1949 representatives of Bulgaria, Hungary, Poland, Rumania, the Soviet Union, and Czecho- slovakia met in Moscow. The participants in this meeting to organize broader economic cooperation recognized the need to create COMECON. In April of the same year the first meeting of the COMECON Session was held and began the practical activity of the organization. Now the members of COMECON include 10 socialist governments: Bulgaria, Hungary, Vietnam (since 1968), the GDR (since 1950), Cuba (since 1972), Mongolia (since 1962), Poland, Romania, the Soviet Union, and Czechoslovakia. The member-nations of COMECON, with a population of 437 million, are developing relations on the principles of socialist internationalism, com- plete equality, mutual advantage, and friendly assistance to one another. During the three decades, the coun- tries of the socialist community have made impressive advances in developing their economies and jointly solving the large-scale problems of scientific?technical progress. Their national income in 1978 was 10 times that of 1948 and industrial production has increased by 17 times. The member-countries of COMECON, oc- cupying 18.7% of the territory and having 10.4% of the population, now produce about one-third of the world's industrial output, including generating 21% of its electricity, extracting 19% of its oil and 27% of its natural gas, and making 30% of its steel. With joint efforts involving the participation of more than 3000 scientific- research and design-construction organizations, more than 14,000 theoretical and applied projects have been completed, many of which have found practical application and have had a significant economic effect. The year 1979 also marks the 25th anniversary of the peaceful use of atomic energy (startup of the first nuclear power plant in the world at Obninsk) and the start of national scientific centers in the member-nations of COMECON. By organizing such centers with the technical aid of the Soviet Union they have been able to be- gin nuclear research and train scientific staff in a comparatively short time. Thus, already in 1957-1958 re- search reactors were built and put into operation in Romania, Czechoslovakia, the GDR, and Poland, and later in Hungary and Bulgaria. These centers are equipped with other modern experimental equipment as well: charged-particle accelerators, and apparatus and equipment for nuclear physics and radiochemical research. The staffs (physicists, chemists, energy experts) needed for these purposes were trained in Soviet institutes. The creation of their own scientific-research base in the socialist countries has led to a need for ex- change of scientific?technical achievements, and the expansion of communication, coordination, and coopera- tion with regard to scientific developments on a multilateral basis. The first major step in the organization of multilateral collaboration was the creation of the Joint Institute for Nuclear Research (JINR) at Dubna in 1956. The entire world now knows of the great scientific achievements of this international collective of scientists who are successfully carrying out experimental and theoretical research in elementary particle physics, nu- clear and neutron physics, biophysics, and solid-state physics. In 1976 the Institute was awarded the Order of Friendship among Peoples for advances in fundamental research and on the occasion of its 20th anniversary. Two further major achievements at the Institute in recent years should be noted: the startup of the powerful U-400 isochronous heavy ion accelerator in December, 1978 and the physical startup of the IBR-2 pulsed fast reactor and the LIU-30 high current injector in the same year. The second important step in multilateral collaboration was the organization in 1960 of the Permanent Commission of COMECON on the Peaceful Uses of Atomic Energy, in which the participants are Bulgaria, Hungary, Vietnam, the GDR, Cuba, Poland, Romania, the Soviet Union, and Czechoslovakia. Its operating experience has shown that the Commission's activity is of considerable help in developing and strengthening collaboration among the member-nations of COMECON and in creating the prerequisites for efficient entry of nuclear technology into the national economy. The working organs (on reactor technology and nuclear power, on the processing and decontamination of radioactive wastes, on apparatus and installations for nuclear tech- nology, and on radiation safety) of the Commission, meetings of specialists on various problems in nuclear Director, Department for the Peaceful Uses of Atomic Energy of the Secretariat of COMECON. Trans- lated from Atomnaya itnergiya, Vol. 46, No. 5, pp. 299-309, May, 1979. 0038-531X/79/4605-0351 $07.50 C11979 Plenum Publishing Corporation 351 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 OZEil ? . _ a - Bulgaria. The Kozlodui nuclear power station. science and technology, and the Secretariat of COMECON (the Department for the Peaceful Uses of Atomic Energy) play an important role in the main activities of the Commission. The multilateral scientific?technical collaboration in the framework of the commission encompasses broad areas of reactor science and technology, of nuclear power and its fuel cycle, of the construction of nu- clear equipment, of the production and application of nuclides and sources of ionizing radiation, of radiation protection technology, of radiation safety, and of standardizing components for nuclear technology. The colla- boration is realized on the basis of five-year plans, working plans on individual topics, 2-yr organizational? technical plans for the Commissions operations, and annual plans in the area of standardization. The most important work is included in the operating plans of the Executive Committee and in the combined documents on interdisciplinary problems of COMECON. The Commission develops and coordinates prospective plans for cooperation. Thus, the five-year plan for scientific?technical cooperation in 1976-1980 envisions work on 15 major problems which presently cover more than 80 themes. About 90 scientific-research, construction, and industrial organizations are involved in this work. The delegation of the Soviet Union plays an invaluable role in the work of the Commission. The most perceptible results achieved by the member-nations are in the development of reactor tech- nology and nuclear energy. The discussion on the design engineering materials for an 880-MW nuclear power plant with two VVkR-440 reactors prepared by the Soviet delegation, the collaboration on the VVER-1000 reac- tor, and the results of joint work on the reliability and safety of nuclear power plants, on the reprocessing and decontamination of radioactive waste, and other problems have had a significant effect on the formation of national programs for the development of nuclear power in the member-nations of COMECON. The results of this work are graphically obvious. While in 1960 only the Soviet Union had nuclear power stations, in 1979 they exist in Bulgaria, the GDR, and Czechoslovakia, one is being built in Hungary, and preliminary work for build- ing nuclear power plants is being done in Cuba, Poland, and Romania. The growth in nuclear power plant out- put is also indicative: 1960? 105 MW (USSR), 1965 ?465 MW (USSR), 1970? 1100 NM (GDR and USSR), 1978 ? 12,000 MW (Bulgaria, GDR, USSR, Czechoslovakia). To ensure this output, the Soviet has given the necessary design and technical documentation to the member-nations of COMECON, constructed the basic technological equipment, and provided technical help in building the nuclear power station, in startup and repair work, and in training the necessary staff. 352 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Hungary. The teaching reactor building at the Central Institute for Physical Research. The Overall Program for Socialist Economic Integration adopted at the 25th meeting of the COMECON Session in 1971 is of considerable importance for the accelerated development of nuclear power. This program envisions the further development and effective entry of nuclear energy into the national economies. In ac- cordance with this program, in recent years multilateral cooperation has concentrated on building and utilizing high power reactors using thermal and fast neutrons. Here the most important task is completion of work on the development and introduction into commercial use of a plant with an output of 1000 MW (the VVER-1000) which employs thermal neutrons and the accelerated development of a 1600-MW fast reactor (the BN-1600). In the current five-year plan the member-nations of COMECON have spent 200 million convertible rubles on scientific-research and engineering experimental work on these problems. Important developments have been realized in the course of this work: in Hungary a boron concentration meter has been developed and is being tested in the Kozlodui nuclear power station in Bulgaria and at the NVAES; in the GDR cluster systems for controlling the core of the VVER-1000 havebeendeveloped and are being tested jointly with the Soviet Union, a test version of an apparatus for determining the moisture content of steam has been constructed, and meth- ods and apparatus have been developed for noise diagnostics of reactors; a device for monitoring inside a reac- tor and for monitoring the neutron flux of high power reactors has been constructed in Poland and the Soviet Union and is undergoing tests at the Kozlodui and Bruno Leuschner (GDR) nuclear power stations, at the NVAES, and at the Kolskaya nuclear power station (USSR); and, in Czechoslovakia modular steam generators for fast reactor nuclear power stations, high-capacity high-speed pumps for the primary loop of power stations using the VVER reactor, and a system for monitoring the metal of the vessel by acoustic emission as the reac- tor is operated have been developed. In accordance with the prograrnfor cooperation in the area of fast reac- tors, joint efforts have been undertaken by specialists from the member-nations of COMECON on fundamental studies on physics and hydrodynamics, programs for computing the complex physics of a breeder reactor, including a calculation of the burnup and refuelling, have been developed, an automatic plug indicator of im- purities in the sodium coolant has been developed and tested, methods and devices have been developed for studying the dynamics of reactors using the oscillator method, neutron spectra have been measured, and so on. The Commission determines the questions which are to be worked on under the agreements. They in- clude the development of a system for obtaining and processing information on the working state of a power reactor, cluster regulators for the VVER-1000, and a system for monitoring the metal in the reactor vessel by an acoustic emission method, as well as experimental and computational studies on the heat transfer crisis in bunches of rods with a perforated barrier. Equipment will be built for an experimental prototype nuclear power station with a 300-MW fast reactor with a dissociating coolant. Also to be built are a high-power steam generator, prototype hydrogen, oxygen, and carbon monitors for the sodium loop, systems for acoustically detecting water and sodium flows in steam generators, and an/experimental loop for the Maria reactor in Poland for studying emergencies in the cooling loop of the VVER. Radiation tests will be made of the fissile and construction materials and tests will be made of the fuel elements in the midst of the dissociating coolant in the Mariya reactor. Experimental and computational studies are to be made of the heat-transfer crisis in 353 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 GDR. Installing the core of the Bruno Leu- schner nuclear power station. Cuba. A subcritical assembly at the In- stitute for Nuclear Research. bunches of rods in nonstationary regimes including loss of coolant emergencies. Some of these tasks have already been completed. An important step in the collaboration among the member-nations of COMECON and in the activity of the working units was the development of long-term cooperative program goals which are a further extension and realization of the complex Program. About 250 measures have been specified, including some providing for the economic requirements of the member-nations of COMECON for the basic forms of energy, fuel and raw materials and on the development of mechanical engineering based on specialization and cooperation in production, including the manufacture of equipment for nuclear power. The following problems are included in the subprogram of the Commission on Electric Power: the construction and utilization of power plants with water-cooled?water-moderated (VVER) reactors with electrical power outputs of 1000 MW and the further improvement of this type of reactor; the development of high-power fast reactors (with sodium or dissociating gases as a coolant); and, the development of reactors for nuclear thermal power stations and for nuclear heat supply installations to produce industrial steam and provide central heating. The delegations of the member-nations of COMECON to the Commission participate in working out the measures for realizing the Program for the maximum possible development of nuclear engineering production in the member-nations of COMECON. This Program is a composite part of the Long-Term Program for de- veloping mechanical engineering on the basis of specialization and cooperation in production. The fuel and energy problem is crucial to the collaboration among the member-nations of COMECON. Thus, at the 32rd meeting of the Session of COMECON (June, 1978), which took place at the level of heads of government, the Long-Term Goal Program for cooperation in energy, fuels, and raw materials, was estab- lished as a program of primary importance. This program envisions the accelerated development of nuclear power, an increased yield and improved utilization of the countries' own reserves of solid fuels, a provision for the further development of Combined Electrical Energy Systems, etc. The construction in the European member-nations of COMECON and in Cuba of nuclear power plants with a total power of 37 GW with the technical assistance of the Soviet Union by 1990 and the joint construction by interested countries of the Khmelnitskaya nuclear power station with a power of 4 GW from VVER reactors 354 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Poland. The building for the Maria research reactor at the Institute for Nuclear Re- search at Swierk. to deliver energy to these countries will play a significant role in solving the energy problem. Realization of the prospective program for the development of nuclear power requires efforts to create a nuclear engineering industry and to speed up the introduction of nuclear reactors with individual powers of 1000-1500 MW. At this time the member-nations of COMECON and the organs of the Council together with the "interatomenergon organization are completing the preparation of an agreement on multilateral inter- national specialization and cooperation in the production and mutual deliveries of nuclear power station equip- ment for the periods until 1990. This will also be aided by the electric transmission line (1113 750 kV) con- structed in 1978 by the joint efforts of the member-nations of COMECON, which will make it possible to reliably build large nuclear power stations with powers of 4-5 GW at a single site. The large-scale development of nuclear power requires substantial financial, material, and labor ex- penditure. The maximum economic efficiency can be achieved by correct choice of the optimum development paths. In this regard work on forecasts occupies an important place in the Commission's activity. Planning studies have shown that the best way of solving the fuel problem is the introduction of fast breeder reactors which makes it possible to improve the structure and fuel consumption levels of the nuclear power system. The Commission devotes considerable attention to collaboration on improving and efficiently using re- search reactors. Work done for this purpose is of practical importance in the development and utilization of nuclear power reactors. Of these results the following should be noted: mastering the techniques of manufacturing threshold detectors for determining the energy spectra of fast neutrons (in the Soviet Union); the development of criteria for comparing the methods and equipment used for measurements inside reactors in order to standardize them within the COMECON framework; the development of nondestructive methods for determining the burnup of nuclear fuel (in Poland and Romania); the development of continuous detectors for measuring the neutron flux density (in several countries); and the creation of calorimeters for determining the energy release in fuel elements and construction ma- terials. Work has been done on monitoring and controlling research reactors by means of computers, an effort which is of great practical interest for creating automatic monitoring and control systems for nu- clear power stations. In recent years there has been a considerable expansion in the experimental prospects for research reactors in Hungary, the GDR, Poland, Romania, the Soviet Union, and Czechoslovakia as they have been rebuilt and their powers have been increased. New high-power research reactors have been built. This makes it possible to carry out a broad program of research in nuclear physics, solid-state physics, and the radiation 355 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Romania. The electrostatic charge exchange accelerator at the Institute of Physics and Nuclear Technology. properties of materials and to obtain valuable data for the design and utilization of nuclear power plants. One efficient form of,collaboration is the activity of the Provisional International Scientific-Research Collective in reactor physics research on a VVER type critical assembly (at the Central Institute for Physical Research of the Hungarian Academy of Sciences in Budapest) which was organized on the Commissions' initia- tive in 1972. Work on improving available and developing new computational programs and measurement techniques for water-cooled?water-moderated (VVER) reactors is an important contribution to the creation and modernization of the cores of VVER-type reactors. The development of nuclear power is inseparably coupled to improvements in the fuel cycle and the solu- tion of complex problems in the reprocessing of spent nuclear fuel and the decontamination and burial of radio- active wastes. Scientific?technical collaboration in this area is characterized by cooperation and sharing of work,- the carrying out of technical tasks, and the systematic presentation to the member-nation of annotated reports for discussion at the sessions of the working unit of the Commission. A scheme has been developed for reprocessing nuclear fuel using tributyl phosphate and a heavy non- combustible diluent and is intended for reprocessing fuel elements with uranium burnup of about 30,000 MW days / ton. A further improvement of this scheme will make it possible to use it for fast reactor fuel element reprocessing with a burnup of roughly 100,000 MW days/ton of uranium. The apparatus and process have been developed for reprocessing nuclear fuel by a fluoride method which is used for finishing off the optimum variant of the gaseous fluoride method for recovery of fast reactor fuel elements, including BOR-60 fuel elements. The optimum capacity of a radiochemical plant has been determined and criteria have been established for choosing its site. Apparatus have been developed for the engineering design of nuclear fuel reprocessing schemes: small-scale fluctuation, turbine, and centrifugal extractors of various sizes and types (Poland and the USSR), a screw dissolver made of stainless steel, electromagnetic batchers, mixing and settling tanks, fluctuating columns (USSR), and others. The technology and apparatus have been created for removal of fuel- element jacket materials by thermal dissection; this method makes it possible to remove both the stainless , steel shell (from the fuel elements of fast reactors) and the zirconium shells from the oxide fuel for the VVER. For monitoring and controlling the reprocessing of spent nuclear fuel, devices have been made for radiometric determination of uranium and plutonium and for the simultaneous determination of uranium and free nitric acid. Also a neutron method for measuring the levels of solutions and an acoustic method for monitoring the location of the phase interfaces in chemical apparatus, as well as neutron level meters and thermal flowmeters, have been developed. In order to increase the efficiency of fuel, use in nuclear power plants and to increase the accuracy of determinations of the amount of valuable components in spent nuclear fuel, specialists from the GDR, Poland, Romania, the Soviet Union, and Czechoslovakia are comparing measurements of the amounts of these components in solutions of spent nuclear fuel from VVER reactors (the SROK experiment). An important link in the fuel cycle is the transport of spent fuel from a nuclear power station to the re- processing site. Extensive work has been done on the construction and unification of transport, the technical conditions for the assembly of spent VVER-440 fuel elements have been worked out, and a special container 356 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Soviet Union. The V. I. Lenin Nuclear Power Station in Leningrad. has been developed for safe transport of fuel from a nuclear power plant based on a VVER reactor. As a re- sult of this collaboration, rules for the safe transport of spent nuclear fuel from power stations in the member- nations of COMECON have been developed which regulate technical and legal matters. One of the determining factors in the development of nuclear power is the rational and safe decontamina- tion and removal of radioactive wastes produced by nuclear power stations. In recent years research and ex- perimental work has been done in the member-nations ofC01VIECONwhichwill serve as a basis for the safe burial of solidified radioactive wastes. In Bulgaria, the GDR, Poland, the Soviet Union, and Czechoslovakia a large amount of data has been obtained on the rate of leaching of radionuclides from blocks made by adding various radioactive wastes to bitumen. In the GDR a process has been developed for solidifying liquid radio- active waste with concrete and ash from filters at thermal power stations. In Poland research has been done on reducing the rate of leaching of cesium and strontium and recommendations have been developed for the use of condensate resins and bentonite for this purpose. In the Soviet Union the mechanism of the radiation processes occurring in bitumen blocks of various composition and specific activity have been studied. In Czechoslovakia additives for increasing the degree of bonding of strontium and cesium isotopes in bitumen blocks have been studied. In the Soviet Union and Czechoslovakia a combination of equipment for bitumenizing nuclear power plant waste has been tested which demonstrates that standard equipment from other branches of industry (film apparatus, extruders, roller driers) can be adapted for bitumenizing radioactive wastes. In the course of the collaboration, much work has been done on methods of burying radioactive wastes in geological formulations. The possibility of creating burial sites in various layers on the earth's surface has been studied: in surface levels (Hungary and Czechoslovakia), in deep aquiferous strata (USSR), and in salt formations (GDR). As a result, a technological basis has been created and experimental tests are being made of centralized underground burial sites for liquid, solid, and solidified radioactive waste of low and medium activity. Because nuclear power plants have been in use in the Soviet Union, Bulgaria, and the GDR for a long time, experience has been gained in organizing and carrying out work on the decontamination of surfaces and 357 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 equipment in nuclear power stations. This experience has made, it possible tp- jointly develop a standard ap- paratus for decontamination of equipment in nuclear power stations with VVER-440 reactors. The use of nuclear energy in industry, agriculture, and medicine has brought a new technology into being: nuclear and radioisotope instrument manufacture. Originally, the instruments and apparatus of nuclear technology were developed and,made in the scientific centers and pilot plants of the member-nations of the COMECON. Later, as cooperation developed and with the technical aid of the' Soviet Union, this equipment has gained a secure place .at such well-known firms as the "Electron" company in Sofia, the "Gamma" firm and the EMG factory in Budapest, :the VEB "Otto Schon" in Dresden, the "Polon" works in Warsaw, and the "Tesla" firm in Prague. ? - The scientific-technical and industrial potential which has been created has made it possible to organize multilateral collaboration among the member-nations of COMECON in the area of nuclear instrument manu- facture, taking into account the future development of power reactors and the need to develop and manufacture the instrumentation system for nuclear power plants. Thus, a group of instruments have been created for nu- clear power plants using VVER reactors which monitors for radiation safety at the plant site and for fulfill- ment of the norms for emission of radioactive aerosols, and also provides for individual dosimetric moni- toring of the personnel. This group of instruments is included in the design of the fifth unit of the NVAES (nu- clear power station), in the third and fourth units of the Bruno Leuschner nuclear power station, and in the Dukovany nuclear power station in Czechoslovakia. In 1r6-1978 a large amount of work was done in the GDR to determine the location of the regulator units in a VVER-440 reactor with a computer readout, and instru- ments for diagnosing the reactor were constructed. Specialists from the GDR, Poland, and Czechoslovakia have been involved in work to construct an instrument for measuring reactivity. In Hungary a second draft was prepared on the technical requirements for instruments for continuous monitoring of the concentration of-boric acid in the coolant of a V1162. The technical specifications for promising new types of scintillation and gas- filled counters are being worked out in CzechOslovalcia and Poland, respectively. -The delegation of the Soviet Union to the Commission has prepared a proposal on the development of an analysis and forecast of the develop- ment and improvement of equipment for the manufacture of nuclear power plant instrumentation through 1995 and the Polish delegation heads the collaboration among the member-nations of COMECON and CAMAC instru- mentation. The important contribution of Hungary, especially the "Gamma" firm, in organizing collaboration and directly working on systems of instruments, apparatus, and installations for nuclear medicine, including mastering the production of the MV-1b0 gamma camera for radioisotope diagnostics with an extensive data analysis system, should be noted. In order to enhance the effectiveness and practical yield of the collaboration in the area of nuclear in- struments and apparatus, the International Economic Union for Nuclear Iiistriiment Manufacture "Interatom- instrument" was created in Warsaw in 1972. The goal Of this organization is to satisfy 'completely the needs of the member-nations of COMECON for high-quality nuclear ,instruments and apparatus at the world scientif- ic-technical level. "Interatominstrument" now includes 15 manufacturing and foreign trade organizations from Bulgaria, Hungary, the GDR, Poland, the Soviet Union, and Czechoslovakia. The principal problem of "Interatominstrument," given the large variety and small production runs of the nuclear instrument manufacturing industry, was to organize specialization and cooperation in the items , produced. Already in 1976 an Agreement on Multilateral Specialization in Productiori was 'signed and in 1971 a supplement was added to it to -cover 70 items with an overall volume of deliveries of about 65 million con- vertible rubles over the period 'until 1981. The inventory of Specialized products includes equipment for radio- graphic laboratories; nuclear medical apparatus, radiometersland dosimeters, flaw detectors, automatic probe positioners, etc. The economic activity of the Union is expanding on the basis of a statutory fund of 2,100,000 rubles. An important stage in this activity was the organization in 1975-1976 of threeservice affiliates in Bulgaria ? (Pleven), Poland (Zelena Gura), and the Soviet Union (Dubna) for technical service on their 0\Na-rand imported nuclear instrumentation. A significant profit was realized because of the success of these, affiliates, which, together with income obtained from work on the economic -agreements, made' it possible to cover current ex- penses from the firm's own income without receiving supplementary 'payments from the members of "Inter- atominstrument"; i.e., they were able to become self-sufficient. One of the important tasks of "Interatom- instrument" until 1990 is organizing work on specialization and cooperation on instruments and apparatus for monitoring and control of nuclear power stations using modern computer techniques. In 1974 the Agreement on Multilateral International Specialization and Cooperation in the Production of Isotope Goods was concluded. This agreement has had a noticeable effect on the growth of goods exchange 358 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Czechoslovakia. Welding the vessel of a VVER-440 reactor at the Skoda works. among the member-nations of COMECON, on the growth of foreign trade collaboration, and on improving the quality of isotope production. The inventory now includes 1463 items including 74 specialities from Hungary, 316 from the GDR, 87 from Poland, 113 from Romania, 714 from the Soviet Union, and 159 from Czecho- slovakia. One result of the collaboration in this area was the Forecast of Production and Needs for Isotopes until 1990, which indicates that the production and use of radioisotope items in the member-nations of COME- CON over the next 12-15 years will tend to increase by about 3 times. As a result of the collaboration within the framework of the Commission on Radiation Technology, stan- dards have been produced which determine a single approach to the construction, use, and economics of radia- tion technology equipment intended for obtaining materials with new useful properties, for increasing agri- cultural yield, for the fight against damage to food products, for sterilization of medical materials, and for environmental protection. The Forecast of Basic Radiation Technology and Radiation Equipment Development until 1990 and other specific technical proposals for organization in the member-nations of COMECON of in- dustrial production of items from radiation modified wood, of radiation treated insulators for the electrical industry, and of radiation sterilized medical production have been developed. In the area of radiation protection technology, cooperation is aimed at unifying and standardizing pro- tective equipment and operational technological equipment used in work with radioactive materials and sources of ionizing radiation. Standards have been worked out for furniture and packaging assemblies as well as boxes, chambers, exhaust hoods, and manipulators. Work is under way on standardizing the manufacture of these items. Collaboration on radiation safety is concentrated on such important topics as radiation monitoring of the environment, especially near nuclear power stations, the creation of standards needed for design, con- struction, and safe use of nuclear power stations, the development of measures for prevention of accidents at nuclear power stations and the liquidation of their consequences, working out measures for the reduction of exposure by nuclear power station personnel during normal operation, and providing safe working conditions 35.9 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 with differents kinds of ionizing radiation sources. In this area the standards used in the member-nations of COMECON in their own national efforts have been developed. Much work has been done on the standardization of nuclear technology equipment. The transition to de- vising COMECON standards covering the following four complex themes has been completed: "nuclear instru- ment manufacture, "isotpes and tracer compounds," "radiation protection technology," and "radiation tech- nology." It is intended to develop 47 COMECON standards. The radiation environments of the basins of the Danube River and of the Black and Baltic seas are being systematically studied. In this regard it is important to note the successful completion in August-September, 1978 of a joint expedition by specialists of the member-nations of COMECON to study the radioactivity of the Danube. During the expedition samples were taken at specified points and quick analyses were made of samples of soil, bottom sediments, fish tissue, and algae. The results of the analyses made it possible to conclude that the Danube had not been contaminated by radionuclides. Multilateral scientific?technical cooperation is continually expanding and improving as it encompasses all the new areas of possible application of nuclear methods and materials. Besides the above-mentioned areas, cooperation has recently been organized on the technical utilization of superconductivity and controlled thermonuclear fusion. The Commission and Secretariat of COMECON support constant contact with the Joint Institute for Nu- clear Research (JINR). Representatives of the Institute regularly participate in the meetings of the Commis- sion and its working organs and in many scientific?technical measures. Members of the COMECON Secretariat participate in meetings of the Scientific Council of the JINR. There is a wide exchange of information and ma- terials between the COMECON Secretariat and the JINR. With each year the contacts between the COMECON and the IAEA expand and are strengthened. Repre- sentatives of the IAEA are systematically invited to the Commission's activities and representatives of the COMECON Secretariat also participate in IAEA activities. In September 1975 an agreement was signed be- tween the COMECON and the IAEA to enable further expansion of cooperation in the spirit of fulfilling the economic and scientific statues of the final act of the Conference on Security and Cooperation in Europe (Hel- sinki, 1975). The international economic cooperation among the member-nations of COMECON is an historically based natural process in the development of a world-wide socialist system. It can be said that V. I. Lenin's asser- tion, made even before the victory of the Great October, that, as a counterweight to imperialism which alien- ates nations from one another, socialism will create "new, higher forms of human society when the legitimate needs and progressive hopes of the working masses of every nationality are first satisfied in international unity" [V. I. Lenin, PoIn. Sobr. Soch. (Complete Collected Works), Vol. 26, p. 40], has been realized. The Soviet Union makes a prominent contribution to the development of international economic relations of a new type and to the strengthening of the position of world socialism. Its successes in the building of com- munism, its consistent internationalist policy, and its fight to strengthen peace and for the relaxation of inter- national tension have a deep influence on the course of world events. The Twenty-Fifth Congress of the Com- munist Party of the Soviet Union devoted great attention to the development of external economic links between the Soviet Union and other countries. Primary emphasis will be given in the future to developing and strength- ening cooperation with the socialist countries in COMECON. At the Congress the General Secretary of the Cen- tral Committee of the Communist Party of the Soviet Union and Chairman of the Presidium of the Supreme Soviet of the USSR, Comrade L. I. Brezhnev said: "Together with the fluorishing of every socialist country and the strengthening of the sovereignty of socialist states, their mutual ties become ever closer, more common elements appear in their policies, eco- nomics, and social life, and there is a gradual equalizing of their levels of development. This growing close- ness of the socialist countries is now occurring most certainly as a natural law." LITERATURE CITED 1. "30 Years of the Council for Mutual Economic Aid," Kommunist, No. 3, 15 (1979). 2. Atomic Science and Technology in the USSR [in Russian], Atomizdat, Moscow (1977). 3. I. Barbur et al., At. Energ., 43, 402 (1977). 4. Communique on the Thirty-Third Meeting of the Session of the Council for Mutual Economic Aid, Pravda (June 30, 1978). 360 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 ARTICLES SAFE,TY:RROBLEMS:.JOF SODIUM ? WATER STEAM GENERATORS AND THEIR SOLUTION IN THE USSR V. M. Poplavskii, Yu. E. Bagdasarov, F. A. Kozlov, L. A. Kochetkov, and V. F. Titov UDC 621.039.534.63 Sodium?water steam generators occupy an important position in the scheme of nuclear power stations (NPS) using fast reactors. This has been shown by the experience of operating the Enrico Fermi (U.S.A.), BN-350 (USSR), Phoenix (France), and PFR (Great Britain) NPS. As the various designs of steam generators for fast reactors were being developed, the opinion was expressed that first, no matter what the construction of the steam generator, it is necessary to consider the possibility of an emergency situation due to the en- trance of water into the sodium and in view of this to develop an appropriate system of stand-by shielding of the steam generator; second, with the existing level of technology one can expect that steam generators with a single wall separating the water and sodium can be built whose construction meets the requirements of safety. Because of its economic advantages, it was decided to separate the water and the sodium in the steam generator by a single wall when the BN-350 industrial NPS was being designed. Later, a similar principle of construction was also adopted in the BOR-60 installation. The application of single-wall construction in the sodium?water steam generator made it necessary to study a whole complex of problems related to the safety of these systems. Such studies, which began in the USSR in 1960, included the experimental and design-theo- retical study of breakdown effects originating from various leaks of water into sodium, the creation of methods for making numerical estimates of accidental states of the sodium loop, and the development of schemes and the elements of a system for the stand-by shielding of a steam generator. In this review, we present the main results of a study of this set of problems, and also the approach adopted in the USSR for assuring the safety of the steam generators under discussion. Experimental Study of Malfunctions and the Numerical Methods for Analyzing Accidental Situations. The first experimental studies made in the USSR of effects accompanying the integration of sodium with water under steam-generator conditions were intended to demonstrate the possibility, in principle, of creating a construc- tion which would resist the contact of the coolant when substantial leaks develop. A cycle of studies on various models from those having the simplest content to those repeating the fun- damental features (material, geometry, weakening process, hydrodynamics) of the BN-350 and BOR-60 steam generator tube bundles [1-3] made it possible to expose the processes accompanying large leaks of water into sodium. The studies determined the characteristics of the pressure and temperature variation in the reaction zone and the hydrodynamical phenomena in the sodium loop (the deformation characteristics of the construction elements), while methods were developed for holding the damage parameters within allowable limits. By 1969 these studies had made it possible to formulate the principles of stand-by shielding for BN-350 NPS steam generator [4, 5]. Methods were developed for making numerical estimates of the main parameters (pressure, temperature, coolant flow rates) of the sodium loop in an emergency condition. At the present time several methods are used to calculate these parameters with appropriate computer programs. Thus, in constructing steam generators with large sodium capacity, a method is used whose main assumptions reduce to the following [5]: a) the only reaction used in the calculation is that involving the formation of a hydroxide and hydrogen; b) the interaction reaction occurs instantly. The rate of accumulation of the reaction products is deter- mined by an assigned rate of discharge of water into the sodium, and the quantity of the discharge is not affected by the pressure in the sodium cavity; c) the distribution of the parameters (temperature and pressure) in the volume of the reaction products is uniform; Translated from Atomnaya Energiya, Vol. 46, No. 5, pp. 311-316, May, 1979. Original article sub- mitted April 17, 1978. 0038-531X/79/4605-0361$07.50 01979 Plenum Publishing Corporation 361 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 d) the maximum possible theoretical values of pressure and temperature develop (under adiabatic con- ditions) in the zone of the reaction products at the initial instant; e) the heat exchange of the interaction zone containing the reaction products with the surrounding medium is neglected. The assigned discharge rate of water into sodium and its time dependence are determined from a postu- lated maximal breakdown in the steam generator assumed to be an instantaneous break equal to the total cross section of one tube. This choice was made after a special analysis of the effect of the type of postulated accident on the developing pressure and temperature in the steam generator and second loop. It was shown that this type of accident has more dangerous (from the standpoint of dynamical loads) consequences than any other sequence of gradual opening of even several tubes at the maximum rate that can be predicted from prac- tice, experiments, or calculations. The calculated maximum pressure in BN-350 or BN-600 steam generators under an accidental condition involving instantaneous rupture of the complete cross section of one heat-transfer tube amounts to 9. 105 or 2 ? 106 Pa, respectively. The acoustical approximation is used to take the compressibility of sodium into ac- count. A simplified calculational program which neglects the compressibility of sodium can be used in an ap- proximate analysis of the hydrodynamical effects in the elements of the sodium loop and in the determination of the time-varying pressure field. A calculation method based on a quasistationary view of the processes is used in preliminary multivariate calculations for determining the maximum pressure in the reaction zone. For steam generator construction where the sodium moves in separate channels (e.g., the "inverse" type), a method has been developed in which the rate of discharge of the water into the sodium is determined by the drop in pressure between the steam and sodium chambers in the damage zone, and the interaction rate of the reagents is determined by the process of mass exchange between the sodium and the water through the hydrogen vapor look formed in the sodium channel and also by the interaction of the water reaching the chan- nel with the sodium film remaining on the walls of the channel. The first studies of the characteristics of malfunctions involving small leaks of water into sodium were made in 1962 [1]. It was discovered that as the water enters the sodium in the intertube space at rates of up to several hundredths of a kilogram per second through a calibrated opening 0.5-1.5 mm in diameter, a zone of higher temperature is formed (the reaction flare), followed by arcing over through the adjacent tube wall. Extensive investigations were subsequently undertaken in order to show the main effects associated with small leaks, using experiments both on targets and on models simulating the steam generator junctions. The effect of leak sizes and spacing between specimens on the rate of failure of various materials [6] was studied on targets at sodium temperatures of up to 500?C and steam discharge rates in the range 0.001- 0.011 kg/sec, using pearlite (1Kh2M), ferrite (0Kh12N2M), austenite (110118N10T), and high-nickel (sanicro- 31) steels. It was found that the maximum rate of corrosion-erosion damage obtains when the ratio of the target-nozzle distance to the nozzle diameter is 25. The resistance to failure of the high-nickel steel is 2.5, 3.5, and 6 times as high, respectively, as that of 1ich18N10T, 0Kh12N2M, and 1Kh2M steels (according to the rate at which the mass of steel is carried out in the zone of influence of the reaction products). The study of the effect of temperature, phase, and geometric factors on the failure rate of a material in the zone of small leaks as applied to the conditions which were obtained in a BN-35-0 steam generator provided a means to explain the nature and rate of development of breakdowns in steam generators. It was also found that irrespective of the temperature regime, a small leak in a gas cavity is not accompanied by appreciable self-development and corrosion-erosion damage of the elements of the tube bundle. Special investigations were devoted to the evolution of leaks. It was shown that the sodium temperature has a decisive effect on the self-development of leaks in pearlite (1Kh2M), austenite (Kh18N10T), and high- nickel (Kb20N40V) steels. A reduction in temperature from 450 to 300?C is associated with a drop in the rate of self-development of the leak by almost an order of magnitude, irrespective of the type of steel. Self-de- velopment of the leak is observed when water containing up to 5% by mass of sodium hydroxide is discharged into the air through an opening in 1Kh2M steel. On the basis of this, it can be assumed that the controlling factor affecting the growth in the size of the leak as a function of time is the penetration of the alkali formed from the reaction of the sodium with water in the discharge channel. In the case of the BN-350 steam generator, a model study was made of the dynamics of the susceptibility of the tubes to damage at the onset of a small leak. The typical behavior of the development in time of a small 362 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 leak was found for this type of construction. The analysis of the breakdown situations observed in the steam generators and the comparison of the results obtained with experiment confirmed the possibility of predicting the dynamics of the breakdown processes by studying them on steam generator models. Investigations of small leaks in tube panels [7, 8] showed that failure of materials 'occurs only when local radiation jets are formed, and failure does not occur if the leak is observed along the perimeter of the junction of the tube with the tube panel. Metallographic studies of the specimens showed that along with the leaks in tubes, the failure which occurs is frontal for the pearlite steels and along the grain boundaries in the austenite steels Experimental studies of the leaks of water into sodium were also made on models having inverted con- struction (sodium in the tubes, water in the intertube space). It was found that if the sodium flow rate through the stand-by channel is maintained during a malfunction in an inverted-construction steam generator, the abrasion rate of the steel in the channel approaches the rate found in the usual construction at leak rates above 0.001 kg/sec. For leaks in the range 10-4-10-3 kg/sec, the abrasion rate in the material in the inverted- construction steam generator is almost an order of magnitude less than that found in the usual construction. If a "stopped-up" regime is established while the water is leaking into the sodium in a stand-by channel, the rate of corrosion?erosion failure at the location of the leak drops as the flow rate of the water increases, in contrast to the increased abrasion found in the uninverted construction. Regimes were observed in which the failure rate of the material in a steam generator using inverted con- struction was the same whether the coolant flow was stopped up or not. However, the rate still remained less than the rate under the conditions of the uninverted steam generator construction. Up to now, the design-theoretical investigations in the USSR in the field of small leaks of water into sodium have been made to develop methods for calculating the parameters in the flare of the reaction in order to obtain additional data (along with experimental data) that would explain the mechanism of failure of mate- rials. A method based on the behavior of the turbulent heat and mass transfer was proposed for the purpose of calculating the field of concentrations, temperatures, and velocities in the region of the reaction flare [9]. At the present time there have been developed criteria and methods for analyzing experimental data in order to establish requirements for a stand-by shielding system of a steam generator in the "small leak" regime. The characteristics of a system of stand-by shielding of a steam generator are considered as satis- factory if the time required for an opening to develop in the wall between the neighboring and the current tube is less than the overall time required for detecting the leak and evacuating the steam?water cavity. Two meth- ods are used to obtain this overall time as applied to the conditions of the steam-generator construction being analyzed. The first method is based on two experimental relationships: the behavior of the increase of the leak in time (self-development) and the dependence of the rate of damage of the material on the size of the leak (at each point of this functional relationship, the leak is constant in time). The required parameters which characterize the malfunction and the requirements for the shielding systems of natural steam generators are found by jointly analyzing the above data. It was in this way that small-leak malfunctions were studied as ap- plied to the BN-350 steam generator installation. The second method is based on the assumption that the leak which originally developed stays constant throughout the whole time of the damage process in the adjacent tube wall. The experimentally determined relation between the size of the initial leak and the time interval from the moment a small leak starts to the time it suddenly begins to increase (the experiments were done with a minimum amount of water entering into the sodium) was used as a starting relationship, as well as the relationship between the size of the unvarying (in time) leak and the rate of failure of the adjacent tube material. If the time that such a leak exists at a con- stant level is larger than the time required for the tube wall to fail during the process, the failure time is used as the maximum allowable. The time of existence of the leak at a constant level is used as the controlling quan- tity with an inverse relationship. A similar method was used to analyze the small-leak regime for a BN-600 steam generator. Steam-Generator Construction and Breakdown Processes. Requirements for a System of Stand-By Shield- ing and the Development of Its Elements. It is well known that shell-type steam generators were the first types of sodium?water steam generators constructed in the USSR (at the BOR-60 and BN-350 nuclear power stations). With this type of construction it is almost impossible to localize the zone of failure or the damaged element, and therefore the whole steam generator is taken out of service in case any leak of water into the sodium de- velops in a malfunction. An appropriate stand-by shielding system (SSS) was developed, which was linked to the 363 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 construction characteristics. This system must also form an emergency signal at the proper time for any size of the initial leak of water into sodium (so that small leaks that arise are not allowed to become large ones), and also to ensure the safety of the construction after the emergency signal is received. The main character- istics of the SSS (compensated volumes, quick operation of the equipment in water, number and nature of the safety devices, and the hydraulic characteristics of the run-off lines, separating devices, expanders, etc.) must satisfy the previously stated requirements with due regard for a possible "large-leak" regime. As shown by the experience of operating the BN-350 steam generator, the SSS which was developed satisfactorily handled the problems of preventing the failure of the elements of the sodium loop in the presence of large leaks.. However, when the steam generator was operated in the small-leak regime at high tempera- tures, the stand-by shielding system did not prevent the small leaks from becoming large. This is mainly due to the fact that at the time the BN-350 was being developed and installed (1965-1971) the characteristic self- development time of small leaks was not yet known. The tendency to limit the reaction zone of the sodium-water interaction to within the confines of a small element comprising only part of the steam generator and also considerations of a technological nature subse- quently led to the creation of structures whose heat-exchange surfaces are placed in small modules connected in a unit (sectioned steam generators) pa]. As is known, a sectioned steam generator is being proposed for use in the BN-600 nuclear power station [11]. The main operating regime of the SSS of this steam generator on the appearance of a leak in one of the sections is a disabling of the whole steam generator. The cut-off fittings in the steam-water and sodium channels of each section make it possible to detach the stand-by sec- tion after a shutdown of the steam generator and then starting it up using the effective elements. The algorithm of excluding the damaged section while the equipment is in operation is proposed for use as an auxiliary regime of the SSS (in case a section is discovered in time at the small-leak level). A system of stand-by shielding of sectioned steam generators is now being developed in the USSR, based on the stipulation that the stand-by section is disconnected without shutdown of the steam generator for any leak, with the main requirements for the SSS being [12]: a) at the moment a signal is received indicating the presence of a leak in the steam generator by means of a subsystem forming a malfunction signal, there must be provided an assured selectivity (identifi- cation of the stand-by section); b) after detection of the stand-by section, it must be isolated at the proper time from the main loop and from the remaining effective sections of the steam generator (i.e., until the time the maximum allow- able corrosion-erosion deterioration of the construction elements is reached or until reaching the maximum allowable contamination of the coolant of the main loop by the reaction products); c) the criterion of quick operation in disconnecting the damaged section in the sodium and steam-water channels must be the prevention of the entrance of the reaction products from the stand-by section into the main circulating loop in the "large-leak" regime (instantaneous and total failure of one tube); d) the shielding system must prevent the pressure from rising above the maximum permissible value not only in the main sodium loop, but also in the excluded section, i.e., to ensure the safety of the stand-by element; e) irrespective of the size of the leak, the coolant of the isolated section must be totally drained at the proper time along the steam-water and sodium loops and the spaces filled with an inert atmosphere. The required characteristics of the SSS elements (sensitivity and time constant of the system for in- dicating large and small leaks, quick operation of the fittings, etc.) which satisfy the above requirements are determined with allowance for corrosion-erosion failure of the material in the leak zone, and also with allow- ance for the parameters of the sodium and steam-water channels of the steam generator [12]. The experience in operating the steam generator of the BN-350 installation confirmed the need for draining the coolant with the reaction products at the proper time, since the duration of stay of corrosive products within the confines of the stand-by zone led to considerable secondary corrosive failure of the tube bundle elements. As shown by analysis, the use of sectioned steam generators with appropriate SSS makes it possible to shorten the time the reaction products act on the structural elements of the stand-by section, and to decrease the total contamination of the sodium loop even allowing for the growth of the leak with time (the small volumes of sodium and water within the confines of the stand-by section and the use of fast-acting mechanisms leads to a rapid drainage of the section with respect to both loops and to its isolation from the effective elements). In view of this, it appears to be possible in principle to simplify the system for indicating small leaks through 364 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 the application of quick-acting devices with a certain reduction of the requirements for their sensitivity (the use of simplified acoustic systems, magnetic flow gauges, etc.). The development of the elements of a system of emergency shielding for sodium?water steam genera- tors in the IJSSH iaproaeeding in several directions at the present time. Systems for measuring hydrogen concentration in sodium and in gas cavities are being introduced as a way of indicating small leaks. The con- centration-measuring devices involve diffusion membranes (in sodium or a gas) combined with a magnetic discharge pump. Allowing for possible signal overshoots, the sensitivity of the system for indicating hydrogen in sodium which was obtained in a test lasting 1000 h was 5 ? 10-6% by mass. A group of experiments on the BN-350 shows that it is possible to reach a sensitivity of ?(1-2) ? 10-6% by mass under industrial conditions. The sensitivity of the devices for indicating hydrogen in gas is 10-3% by volume, which can be considered as completely acceptable with existing background concentrations. A group of studies of instrumentation noise in the BP-10, BOR-60, and BN-350 reactors was used for developing acoustic systems, plus an analysis just of the noises of the leaks of water into sodium with models. Devices that record the change of pressure in gas cavities as well as the flow of sodium in the sections (for sectioned construction) are used to indicate large leaks in steam generators. Membranes that undergo spontaneous or forced rupturing in the gas cavities are used as safety devices in steam-generator SSS. Hydraulically driven equipment with action times as low as 5 sec was used for emergency drainage of the steam?water loop. Fast-acting sodium equipment is being de- veloped for the sectioned construction. Systems for the discharge and separation of the reaction products use a design for two-stage separation by changing the direction and velocity of the gas?liquid mixture. Cycle-type devices are not used. Conclusions. From the results of experimental studies on models, computer investigations based on methods which have been developed, and the analysis of malfunctions in BN-350 steam generators, it is now possible to give a fairly complete description of the evolution of breakdown processes for various leaks of water into sodium (large and small leaks). The experience of the BN-350 is of fundamental importance from the point of view of the possibility of combining sodium and water in an NPS scheme and the validity of separa- ting them by one wall in industrial steam generators. It was shown that even when considerable water enters the sodium, it is possible to contain the breakdown processes within the sodium circuit without it disintegrating. The presently available information about breakdown processes associated with a leak of water into so- dium makes it possible to formulate the main requirements for a steam generator and its stand-by shielding system (the sensitivity of leak-indicating instruments, the response speed of protective devices, the charac- teristics of the discharge and separation devices, etc.) which would not only ensure the safety of the NPS, but also to reduce to a minimum the size of the failure of the steam-generator elements and the extent of con- tamination of the coolant by the reaction products in a breakdown regime. In view of this, a steam generator with sectioned construction and an appropriate shielding system has certain advantages which make it possible to contain the breakdown effects within the confines of the damaged section and to ensure (when necessary) the continuous operation of the steam generator on the effective sections no matter what the size of the initial leak of water into the sodium. LITERATURE CITED 1. V. M. Poplavskii et al., Teploenergetika, 6, 70 (1966). 2. A. I. Leipunskii et al., At. Energ., 22, No. 1, 13 (1967). 3. Yu. E. Bagdasarov et al., Technical Problems of Fast Neutron Reactors [in Russian], Atomizdat, Mos- cow (1969). 4. B. I. Lukasevich et al., in: Proc. Study Group Meeting on Steam Generators for LMFBIlts, Bensberg, Oct. 14-17 (1974), p. 239. 5. V. M. Poplavskii et al., At. Energ., 30, No. 2, 191 (1971). 6. A. S. Mazanov et al. [4], p. 129. 7. F. I. Kozlov et al., in: Proc. US/USSR Seminar on the Development of Sodium-Cooled Fast Breeder Reactor Steam Generators, Los Angeles, Dec. 2-4 (1974), p. 367. 8. V. M. Poplavskii et al., in: State and Perspectives of Work on Creating NPS Using Fast Breeder Reac- tors [in Russian], Vol. II, FEI, Obninsk (1975), p. 518. 9. V. V. Petukhov et al. [7], p. 540. 10. V. F. Titov et al. [ 8] , Vol. I, p. 608. 11. V. F. Titov et al. [7], p.243. 12. V. M. Poplavskii et al. [7], p. 488. 365 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 ACCURACY OF NEUTRON FIELD REGULATION IN NUCLEAR REACTORS L. P. Plekhanov UDC 621.039.515 One way to improve the performance of a nuclear power reactor is to increase the accuracy of three- dimensional regulation of its neutron field. The problem is solved by designing field regulation systems equip- ped with several sensors and regulators. The problem has been the topic of several works [1-5] which dis- cussed system design and stability as well as the theoretical and experimental behavior of complete systems. Unfortunately, certain important aspects of the problem have been somewhat neglected. One is the de- pendence of steady-state regulation accuracy on the number and location of sensors and control devices, on the sensor accuracy, on the regulator dead zone, etc. In this article we discuss the relationships that govern the steady-state accuracy of neutron field regula- tion. Formulation of the Problem. Let the deviation A(13(r) of the field from the rated steady-state distribution taking into account internal feedbacks be described by the linear boundary problem L (AO) BIA0 (r)1 =0, r E r, where r is the core boundary; L and B, linear operators; f, an operator; and Aa (r), change in the neutron multiplication constant (the perturbation). The perturbation is assumed to be bounded by one of the following two inequalities with known right-hand (1) sides: if Paz 1 > 2300) since in such conditions the flow velocity is nearly the same as the average flow rate (except for the velocity in a thin boundary layer which can be neglected). Thus, in case of turbulent flow, the average specific activity of the process material at the activity generator exit calculated from the average thermal neutron flux density or obtained taking into account its distribution in the activity generator are practically the same. It has been found however, that the conditions of flow in activity generators of power reactors with complex hydraulic circuits [3] are laminar (Re > 2300 [1]. Translated from Atomnaya Energiya, Vol. 46, No. 5, pp. 341-342, May, 1979. Original article sub- mitted July 28, 1977. 392 0038-531X/79/4605-0392$07.5O ?1979 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Fig. 1. The function AN/T1= f(a, R/L) for FT(0) = N*(0) = 0. a) taking into account the flux density distribution (2), W.+1= N, (0) F 1? F,; b) according to the mean density (3), Wil+L=Tvl (0) exp ? 2a) + [!?exp ( ? 201 (here n is the number of the hot circuit operating run); F = 2xaRL I ( IR ) ; F at! E2 (a)+12? (+! tilr, )2 Ri+ a) E2 (61)?exP (--i1)1; 1?[E, (a) F (b) exp( MOP' Fin (0) = (Fi FE 1?E, (a) E2 (b) exp (?Xth) ' (4) (5) 1?(exp [ ?2 (a+ b)] exp (? 24)}n -ATt (0) = F1 [1 ?exp (-2a)] 1?exp [-2 (a ? b)] exp (?Xth) a= 1.Vp/2G; b = Wy/2G; a= laact K IactXcg where Vy is the volume of process material in the irradiator; t, time the material stays in the connections; E2, integral exponential function; and K, a dimensional factor. Analysis of expressions (4) and (5) indicates that for given process material characteristics and nuclear reactor parameters 3 and Tr* are determined by the magnitude of Re during the motion of fluid in the activity generator and irradiator and by the number of the hot circuit operating runs. Figure 1 shows the function AN/174 = ?51*) /R for the case when R(0) = R*(0) = 0 (first hot circuit run) for different R / L. The figure shows that for a 0 to within ?10%, a convenient practical expression for AN/ N at a a- 0.1 for the n-th hot cir- cuit operating run is AN 1 + E2 (a) 1? exp (-4an) ? 1 1?exp (-2a) 1?Er (a) ? (6) For a < 0.1, expression (6) gives an error >10%, and in this case AN/ N should be determined from the rela- tions (4) and (5). Obviously, when 0.1 a < 1, AN/R has a maximum at n = 1. In transitional conditions of the nuclear reactor and hot circuit (activity saturation of the hot circuit or changing the nuclear reactor power) AN/R decreases when the number of operating runs increases. In case of activity saturation (n? AN/li depends, if only weakly, on a and amounts to ?10%. 34.3 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Thus, when using liquid-phase process materials with high thermal neutron absorption cross sections (ten to hundreds of barns) and short (of the order 1 h) half-lives of produced isotopes, the y-radiation power of the hot circuit should be calculated taking into account the hydrodynamic conditions of flow of the process material. In conclusion, the authors thank N. P. Syrkus for useful discussions. LITERATURE CITED 1. A. Kh. Breger et al., Principles of Radiation-Chemistry Equipment Design [in Russian], Atomizdat, Moscow (1967). 2. A. S. Dindun, V. V. Gavar, and E. Ya. Tomson, Hot Circuits as Sources of y Radiation [in Russian], Zinatne, Riga (1969). 3. A. Kh. Breger et al., At. Energ., 37, No. 1, 60 (1974). PERFORMANCE OF AN IRRADIATION LOOP CONTAINING NONFISSILE MATERIAL N. I. Rybkin, A. Kh. Breger, UDC 621.039.573 E. S. Stariznii, and N. P. Syrkus Various types of circulation have been employed in new or updated irradiation loops in research reactors 111: direct-flow (Fig. la-c) or with hydraulic decoupling (d-h), with further subdivision in terms of the branch- ing in one or more stages (a, d, and h), in addition to any other differences in the parts within the reactor (generation in one or several stages, as in a-d, g, and h) or in the number of irradiation units (a, c, d, f, g, h). Each of these different schemes has its advantages and disadvantages. For example, a direct-flow scheme is simple to design and gives a high external yield factor n), for the y radiation [2], but it does result in flow in- stability in branched and multiple-irradiation systems and cannot be used if the difference in height between the source and the irradiation unit is much in excess of 10 m on account of the lack of pumps giving appro- priate pressures. Schemes with hydraulic decoupling are free from some of the disadvantages of direct-flow schemes but have lower values for ny, and therefore the optimality of any particular scheme must be con- sidered in terms of reliability, stability, and efficiency, and this requires a detailed examination for each particular design. Here we employ an optimality criterion based on the loss of y-ray flux in a hydraulic sys- tem relative to a direct-flow one: r=1?Tivh/Tlvd? The extraction (yield) factor for a loop that includes / reactor sections and m irradiation sections is: ily = 4,j NI.A /EN 3=1 i=1 where Aj is the steady-state activity of the working substance in irradiator j and Ni is the number of active nuclei formed in 1 sec in section i. A published method [3] enables us to show that where Ai = 111 (1?T1) BS, B E No, Pi1-0,2ro; GpictIact No, Translated from Atomnaya Energiya, Vol. 46, No. 5, pp. 342-344, May, 1979. Original article sub- mitted July 27, 1978; revision submitted December 11, 1978. 394 0038-531X/79/4605-0394$07.50 ?1979 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Vi vi Gj Gi2 25 450 475 Fig, 1 Fig. 1. Designs of irradiation loop. Fig. 2. Curves for y-ray flux loss: r = f(t / Ti/2, Gi/G ) for Gi/Gr = 0.1 (1); 0.2 (2); 0.3 (3);.0.4 (4); 1.0 (5); 2.0 (6); 5.0 (7). Fig. 3. Curves for y-ray flux loss in an RBMK reactor: 1) rh = f(Gii/Gi2, Gi/Gr = 1); 2) rd = f(Gi1/Gi2, Gi Gr = 1); 3) rh= f(GriGi, Gil / Gi2 = 1) for tr / Ti/2 = 0.282, tp/tr = 0.427, VD. = 142 =Vr ( Loi,rc Sd= E Loft ?( E MAI) (E Li012-ki Zif Fig. 2 0,25 450 475 Cr/6 i Fig. .3 (for a direct-flow scheme) and Sh= In (E E itf,)tac i=, In E E Li(Dji+ EMj + EMJAJ 1=1 J=i (for a hydraulic-decoupling scheme). Here Eact is the macroscopic thermal-neutron activation cross section for the working substance; (pi, thermal-neutron flux density; ?a1'("az, thermal-neutron absorption cross sections for the target and product nuclides; A, decay constant; Li = Gri / Gm, M = Gm; Gri, Gii, Gm, volume flow rates in the reactor, in the irradiator, and in the mixing section; 4)d, 41i2,A, Xj, X, "Zj, Xij, exponential functions whose exponents are ?Coicraitri, ?(Pi0a2tri, ?ATri, ?XTij,Atri, ?Xtij, ?Xtpij, respectively; tri, tij, tpij, times spent by the working substance in the reactor, the irradiator, and the pipelines; T, loop working time; Te = (EVri + EVij + ?? /Gm, circulation time; Vr, Vi, Vp, volumes of the working substance in the reactor, irradiator, and pV ij pipelines; and Tri = tri + tpi + tm; Tij = tij + tpj + tm; tm, tpi, tpj, times spent by the working substance in the mixer (volume V) and in the pipelines before and after the mixer (Fig. 1): Nr= Noi(I Li(DiOTirc(:Dii-012-ki); i=1 N ?111 o =N ? (E I mirccoii?Oi21-i). r t i=i 395 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Quantitative evaluation of the effects of the mode of operation on r can be based on schemes with one reactor section (1= 1) and one irradiator (m = 1). Figure 2 shows values for r = f(tr / Ti/2, Gi/ Gr) for the case Vi = 2Vr and tp = 0 (data have also been obtained for to #0). These results show that athigh circulation speeds, i.e., for tr / T1/2 1 and r 0.1, and under such conditions a loop with hydraulic decoupling shows little effect on the y- ray recovery factor. However, r increases considerably with tr / T1/2, especially for Gi/ Gr ? Gr, there is a fall in r (curve 3), while for a direct-flow scheme with the same relationships and the same capacities for the major units one gets only a slight change in r for flow rates in the irradiators within the range 0.25 Gil/ 1, and only for Gil / Gi2 0.2 MeV and for elements with Z 50 gave the following approximating function: Nks= 3.1640-2 [(Um ? 1 ? 1.3 In Um) sox, (3) where Um --- E/3/Ek, Sp = (Emq /Eg)2, Emq is the mean-square /3 spectrum energy. The difference between the Nks values obtained from Eq. (3) and those listed in Table 2 does not exceed ?20%. The obtained results were compared with published theoretical and experimental data. Figure 1 shows the number of K-emission photons in copper as a function of electron energy, and also the data obtained from Eq. (2) which is seen to be in good agreement with known data. Results calculated in [3] are shown in Table 2 within parentheses. It is seen that they do not agree with the results obtained in this work, i.e., the assump- tions made in [3] as to the K-shell ionization cross section and electron energies do not provide satisfactory results in the calculation of K-emission photons generated by g particles. The reliability of the results ob- tained here is ensured by the high accuracy of the relationships on which our calculations are based and by the good agreement of the calculated results with known experimental data. LITERATURE CITED 1. S. V. Rumyantsev et al., Low-Energy Radiation Sources for Nondestructive Testing [in Russian], Atom- izdat, Moscow (1976). 2. W. Hink, Z. Phys., 177, No. 4, 424 (1964). 3. I. Filosofo et al., in: Production and Application of Radioactive Isotopes [in Russian], Atomizdat, Mos- cow (1960), p. 54. 4. Alpha, Beta, and Gamma Spectroscopy [in Russian], No. 4, Atomizdat, Moscow (1969). 5. A. Arthurs and B. Moiseiwitsch, Proc. Soc., No. A247, 550 (1958). 6. Alpha, Beta, and Gamma Spectroscopy [in Russian], No. 1, Atomizdat, Moscow (1969). 407 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 VISCOSITIES OF MOLTEN MIXTURES OF URANIUM TETRAFLUORIDE WITH ALKALI FLUORIDES V. N. Desyatnik, A. I. Nechaev, UDC 532.133:546.161 and Yu. F. Chervinskii Measurements have been made over a wide temperature range and over the entire composition range on the viscosities of molten lithium fluoride, potassium fluoride, uranium tetrafluoride, and binary mixtures of these; damped rotational oscillation of a cylindrical crucible filled with a liquid was employed [1]. The coef- ficient of variation of the kinematic viscosity was 2.0%. Molybdenum crucibles were used in purified argon. The initial salts were dried chemically pure lithium and potassium fluorides, while the anhydrous uranium tetrafluoride was produced by a standard method [2]. The results for the alkali fluorides are in good agree- ment with published values [3]. The molar viscosity ? in erg ? sec/ mole was calculated from the results; also, the activation energy E for viscous flow was calculated in each case. Table 1 gives the results as the coefficients in the equations for the temperature dependence of the viscosity, along with the standard deviations S of the observed viscosi- ties from the fitted equations. An existing model for the structure of an ionic liquid [4] indicates that alkali-halide melts can be con- sidered as mixtures of associated particles, free ions, and vacancies. The complexing agents are the alkali- metal cations, which are surrounded by the larger polarizable halide ions. Exceptions must be made for potas- sium, rubidium, and cesium fluorides, in which complexes based on fluorine are favored by energy considera- tions. These latter complexes should be particularly characteristic of molten halides of polyvalent metals, since elementary cations and anions are unlikely in such media. Alkali-metal cations differ in size and charge from the cations of uranium tetrafluoride, and mixing of such compounds should result in the preferential for- mation of groups based on U(IV), which is highly polarizable. The molar viscosity is directly related to the structure of the melt and should reflect the interaction occurring on mixing. Isotherms for 1230?K were drawn up in order to determine the effects of the composition; the molar viscosity varies with the composition for mixtures of lithium fluoride with potassium fluoride, but the devia- tion from additivity is slight, which may indicate that there are no marked changes in the structure (Fig. 1). In the LiF?UF4 system, particularly at low levels of uranium tetrafluoride, the structured units in- volved in the viscous flow are elementary lithium cations in the second coordination sphere, Li4111-1) ions, and 44 42 2 b0 .4.?0 8 C) > 4 0 20 40 60 80 100 Second component, moll. Fig. 1. Molar-viscosity isotherms for the following melts: LiF?KF (0); LiF?UF (0); and KF?U F4 (A). Translated from Atornnaya Energiya, Vol. 46, No. 5, pp. 354-355, May, 1979. Original article sub- mitted May 29, 1978; revision submitted December 4, 1978. 408 0038-531X/79/4605- 0408$07.50 ?1979 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 TABLE 1. Viscosities of Molten Salt Mixtures Second component MOLO V lg ? =A-I-BIT S. 102 . E, cal/mole Temp., *1( , -A I B L4F--ICF 0,0 1,6284 1223 0,16 5596 1139-1282 20,0 1,6512 1268 0,23 5802 1039-1320 40,0 1,7075 1381 0,51 6319 926-4297 50,0 1,6798 1408 0,69 6443 820--1308 59,8 1,5949 1342 0,48 6141 923--1306 79,9 1,3203 1038 0,37 4750 1139-1306 100,0 1,3729 1189 0,34 5440 1144-1305 LiF--IJF, 15,0 1,4514 940 0,63 4301 1052-1284 20,0 1,0921 994 1,28 4548 977-1293 27,5 1,0546 968 0,43 4429 864-1268 39,9 0,9431 938 1,35 4292 943-1281 50,0 0,9377 1126 1,31 5152 1054-1283 57,8 0,9361 1226 3,38 5610 1077-1295 79,3 1,2426 2059 3,73 9421 1255-1302 ICF--1.11?4 14,0 0,9971 . 988 0,88 4521 1111-4278 24,9 0,8333 1068 2,33 4887 1211-1278 33,2 0,9422 1241 2,04 5678 1159-1270 40,0 0,8697 1135 108 5192 1073--1275 46,0 53,6 0,7893 0,7505 1002 893 2,62 2,71 4585 4085 1101-1267 1072-1253 66,4 0,7196 981 1,58 4489 1090-1252 78,9 1,2800 1886 2,92 8630 1205-1327 400,0 2,0444 3455 3,31 15809 1323-1428 probably also UFi. As the uranium tetrafluoride concentration increases, the alkali-metal complexes are re- placed by uranium ones. The viscosity increases slightly as a consequence. In the KF-UF4 system, the viscosity has a turning point in the composition range corresponding to the congruently melting compound 2KF X UF4 [5], which is evidently due to the heightened stability of the uranium complexes in this composition range. The second coordination sphere in that case contains mainly elementary alkali-metal cations. Any further increase in the uranium tetrafluoride content causes the alkali cations in the second coordination sphere to be replaced by complex uranium cations such as UF r or UF, which is accom- panied by a considerable increase in the viscosity, and the maximum value corresponds to pure uranium tetra- fluoride. The variation in the activation energy of viscous flow with the composition confirms this view of the momentum-transport mechanism. This energy increases considerably at high uranium tetrafluoride contents, evidently on account of the increased number of large uranium cation complexes in the second coordination sphere, which cause difficulties in momentum transfer. The concentration dependence of the molar viscosity in each of the systems containing uranium tetra- fluoride indicates accentuated, interaction between the ions and more complicated structures, particularly on going from systems containing lithium fluoride to ones containing potassium fluoride. LITERATURE ? CITED 1. E. G. Shi:ridkovskii, Some Aspects of the Viscosity of Molten Metals [in Russian], Gostekhteorizdat, Moscow (1955). 2. J. J. Katz and E. Rabinowitch, The Chemistry of Uranium, Part 1, The Element: Its Binary and Related Compounds, Peter Smith. 3. M. V. Smirnov et al., Zh. Fiz. Khim., 48, No. 2, 467 (1974). 4. M. V. Smirnov, Potentials of Molten Chlorides [in Russian], Nauka, Moscow' (1973), p. 201. 5. G. Jana et al., J. Phys. Chem. Ref. Data, 3, No. 1, 1 (1974). 409 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 DETERMINATION OF FUEL BURNUP IN VVER-440 ASSEMBLIES WITH AN "ARAGONIT" RADIATION METER 0. A. Miller, L. I. Golubev, UDC 621.039.516.22 G. A. Kulakov, and Yu. V. Efremov The IAEA safeguards and supervision of nuclear materials require measurement of fuel burnup in fuel assemblies of water-cooled?water-moderated (VVER) reactors. The necessity of carrying out such measure- ments directly at the storage of irradiated fuel assemblies has been pointed out before [1]. Such measure- ments have been carried out at the fuel storage of the fourth unit of the Novovoronezh Atomic Power Plant by taking the 1, radiation spectra of exposed fuel assemblies under a layer of water with the aid of the "Aragonit" radiation meter. The measuring stand, set up in a water pool, consists of a tube surrounded by lead shield =-'80 mm thick and closed at the bottom. The lead shield has a hole into which is placed a collimator 50 mm in diameter, about 2 m long, with a 50 X 5 mm aperture. The measured assembly was placed under water near the collimator and radiation spectra were taken at eight points spaced by 300 mm. The "Aragonit" meter was lowered down the tube so that the Ge (Li) detector faced the collimator (Fig. 1). The "Aragonit" radiation meter is a y detection unit including a planar germanium?lithium semiconduc- tor detector with an active volume of 9.3 cm3. The intrinsic energy resolution of the detector at the 1333-keV line was 2.8 keV with supply voltage V = 2200 V and a differentiation time equal to 2 ?sec; the photopeak/ comp- ton ratio at this energy was 6.8. The detector output signal was preamplified by a charge-sensitive preampli- fier with a noncooled main stage. The preamplifier noise level for zero input capacitance was 12 eV + 49 eV/ pF; its conversion factor was 200 mV/ MeV, the maximum count rate for 1333-keV energy quanta was 2 1014 per second, the overall resolution was 3.3 keV at V = 2200 V and T = 2 ?sec. The detector operating tempera- ture was maintained in cryostat submerged in a special dewar vessel with a shielded-vacuum thermal insula- tion and filled with liquid nitrogen. The capacity of the dewar vessel was 1.2 liters. The time for total evapora- tion of liquid nitrogen from the vessel with the cryostat submerged in it was 21 h for an ambient temperature of 25?C. The detector block was a 1250-mm-long cylindrical bullet with a maximum diameter of 100 mm com- posed of three independent coupled units: the detector in cryostat, the cylindrical dewar vessel, and the ampli- fier in a protective case. Such a construction facilitated handling and storage of the detector block since the detector can be cooled during transportation with the aid of commercial ASD-16 dewar vessels. With such an arrangement the detector block could be held for 5-8 days without liquid nitrogen refilling in a conventional package. The stand was used to analyze type VVER-440 fuel assemblies. Initial enrichment was 1.6%, average burnup was found to be 12 kg /ton U, holding time after exposure was 3 years. The y spectra clearly indicated the presence of 605 (134Cs), 624 (106Ru), 662 (137Cs), 796 and 802 (134Cs) keV lines and certain other. The relative distribution of burnup along the fuel assembly height was determined from the photon count rate at the 137Cs photopeak (Fig. 2). The burnup nonuniformity factor Kz was found to be 1.40 ? 0.1. The fuel burnup in the assembly was found from the ratio of count rates at 134Cs (605 keV) and 137Cs (662 keV) at eight points along the assembly (Fig. 3). The deviation of the obtained values from the experimental curve did not exceed ?12%. The measurements proved the possibility of determining fuel burnup in irradiated fuel assemblies by means of the "Aragonit" radiation meter in a stand mounted directly in the spent-fuel storage pool of the atomic plant. Translated from Atomnaya itnergiya, Vol. 46, No. 5, pp. 356-357, May, 1979. Original article sub- mitted June 29, 1978; revision submitted September 11, 1978. 410 0038-531X/79/4605- 0410$07.50 01979 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 2 3 4 Fig. 1 Assembly length, m Fig. 2 Kcs 0,4 - 0,3 - 0,2 - 0,1 ' 6 0 114 18 Li. 6 1 12 18 Burnup, kg/ton U Fig. 3 20 Fig. 1. Measurement of fuel assemblies in a storage pool: 1) Ge(Li) detector; 2) fuel assembly; 3) lead shield; 4) collimator. Fig. 2. Height distribution of fuel burnup. ?) calculated, 0) experimental. Fig. 3. Experimental 134Cs/ I37Cs ratio as a function of fuel burnup. ?) calculated, 0) experi- mental. LITERATURE CITED 1. S. A. Skvortsov et al., Proc. IAEA Symp. on the Safeguarding of Nuclear Materials, IAEA, Vol. 1, Vienna (1976),.p. 187. MINIMIZATION OF ENERGY DISTRIBUTION INHOMOGENEITIES IN A NUCLEAR REACTOR V. V. Pobedin and V. D. Simonov UDC 621.039.512.45 Minimization of energy distribution inhomogeneities in the reactor core is one of the tasks of the intra- reactor fuel control system. For a known fuel composition, minimization consists in determining the layout of fuel assemblies which gives the minimum energy distribution inhomogeneity factor in the reactor core. Let there be I different combinations p 1 , p2, . . , p1 of neutron physical characteristics of N fuel assem- blies (I N) forming the reactor core and let the vector po describe its composition: = IN, PI ? ? ? P2 9 132 ? ? ? ? ? ? PI, Pi, ? ? ?} N, ? N, Nj Ni= N. t=i Let xn denote the coordinate point (or group of points) corresponding to the n-th cell of the core. The core layout, i.e., the correspondence {xn? pi}, is described by an N dimensional vector p = ii2 piN} belonging to the set of all possible permutations of the components of vector po (in = 1, 2, . . ,1). If operator L(p) corresponds to the boundary problem of neutron transport in the core, the minimization of energy distribution inhomogeneity can be formulated as follows. (r) To find minII K ()11c, where Il K (011c= max 1;-=-7.1 and the function lip(r), which describes the energy distri- bution ? in the core, satisfies the equation L(p)4'p(r) = 0. Translated from Atomnaya gnergiya, Vol. 46, No. 5, pp. 357-359, May, 1979. Original article sub- mitted June 4, 1978. 0038-531X/79/4605-0411$07.50 ?1979 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 411 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Fig. 1. A 300 sector of the VV R-440 core: 1) core cell; 2) cell for SUZ control assembly; 3) cell with fixed fuel assembly. The object function of this integral optimization problem is the energy distribution inhomogeneity factor K(p) and the vector p is its control. Let us assume that K(p) is an analytic function. Then, in the neighbor- hood of the point po = (p1, p2, . . . , pN) the function can be represented to within 0(pi ? p0)2 in the form K(p) E fi (pi) and the problem can be solved using the concepts of dynamic programming, i.e., seeking the solution {=1 as a result of an N-step process of successive determination of the components pin of the optimal control vec- tor ;;? Accordingly, the solution algorithm consists in finding a fuel assembly arrangement trajectory, select- ing optimal control at each step of the optimization process. The algorithm includes determination of the base point ? "exploratory search" [2] and "search by patterns" [3] ? i.e., the determination of the control lio(m) that minimizes the inhomogeneity factor at the step m. The first minimization step begins with solving the boundary problem for a core with neutron physical characteristics )90 averaged over the entire core volume. This is followed by the determination of the base point, a point at which alternate variation of vector components within allowable limits produces maximum re- sponse in energy distribution: K1(1)= K (Po, ? ? ? , Po 71.-- P, IT'o, ? ? ? ) max. /(1) A(1) For the point thus determined and within the limits of the available collection pi, one then finds a pit such that the vector /SP) = {-po, . . . , ,p0,.} minimizes at this step the inhomogeneity factor K((1)) = " min{K{p(1))1. The same operations are repeated at the following steps. The sequence of operations is such that the core cells most sensitive to changes in neutron physical characteristics are filled first and the effect of sub- sequent steps on former ones is leveled out. Completion of each step determines the location of one fuel assembly and the number of empty cells and coordinate points corresponding to them decreases. The number of remaining fuel assemblies and possible controls also decreases. Thus, the neutron physical characteristics of the core region containing vacant cells must be averaged anew after each step. The last step N gives the minimum energy distribution inhomogeneity factor. The above algorithm has been implemented as a computer program. The results of its application are illustrated by the example of minimizing the power distribution inhomogeneity in the VVER-440 reactor core [4] with a composition corresponding to that of the fifth run. We have analyzed a 300 sector of core characteristics periodicity with partially inserted absorbers of the SUZ control assembly group (cells 1 and 7 in Fig. 1). The fuel assembly power distribution has been calculated using the BIPR program [5] based on a lattice with a single node in the fuel assembly cross section. Since the neutron physical characteristics of fuel assemblies are entered into this program as functions of fuel burnup, 412 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 1 20 3 20 A q i V \ Vla3 ? 21 _12 ''' Iii\. R 14 ? 28 22 ?,,,, 12 15 23 J3 '-"N7 F3-29 ,.....4 I 16 23 34 312 2 .34 16 1 76 16 12 12 ------ if ifi 1L3 113 .7 \ 21 ? \23 I 24; 27;32,36 If ,; 32; 205 I ..... ---_,..e-- "??? 12 -----? , 2 23 Z. 717 1,2 , 21 1 1 1 -I 1 1 1 111 1 1 1 11 1 Y 16,...3.3; 7264; /4,29 3 5 7 9 II 13 15 17 19 ZI 23 25 27 29 31 33 35 37 39 41 43 45 47 49 N o. of step Fig. 2. Sequence of determination of base nodes and-variation of the inhomogeneity factor K in the course of optimization: ? --) max Ki (numerator indicates the base node and the denominator, the node of max K1 for a perturbation po ? AP); --) K (figures indicate cells with maximum power). the average concentration of poison in fuel assemblies served as the control. To determine the effect of the initial poison field, the optimization process was divided into several stages. The first stage began with a core in which trickle-feed fuel assemblies were placed, in accordance with the recommendations [6], at the core periphery and with the fuel portions of the SUZ control assembly group inside the core (see Fig. 1). The remaining region (26 cells) was divided into four zones in accordance with the limitations on fuel assembly relocation that dictate the allowable zone size and the number of fuel assem- blies in them and, consequently, also the available controls for each zone [7]. The initial distribution of neu- tron physical characteristics corresponded to the arrangement of fixed assemblies and to the average poison concentration in the zones. The base coordinate point (node) at each step was determined simultaneously for all four zones. Figure 2 shows the sequence of {max Ki} values from which the base nodes were selected, the order of fuel assembly insertion in the cells, and the variation of the power distribution inhomogeneity factor K in the course of the optimization process. The core layout was completed with the 26th step (section I) at which the inhomogeneity factor was found to be 1.246. The specificity of its variation with each step depends on the discreteness of control. At the second stage the initial poison field in the core was formed by dividing the central region (22 cells, with fixed fuel assemblies in cells 4, 10, 27, and 36), obtained at the first stage, into two zones that preserve layout symmetry. These zones include two subzones each with fuel assemblies remaining in the reactor for the same period of time grouped in each subzone. The concentration of poison in each subzone was averaged. Base coordinates were determined individually for each subzone (sections II-V in Fig. 2). The stage ended at the 48th step. The inhomogeneity factor decreased to 1.237 by relocating two fuel assembly pairs with burn- ups differing by 0.15 and 0.3 kg/ton U. The next stages were preceded by testing all the possible versions of averaging of the core character- istics. In all cases the results did not differ from that obtained at the first stage by more than the result ob- tained at the second stage. LITERATURE CITED 1. G. Hadley, Nonlinear and Dynamic Programming, Addison-Wesley (1964). 2. R. Hook and T. Jeeves, J. Assoc. Computer, 8, 212 (1962). 3. C. Wood, "Application of 'direct search' to the solution of engineering problems," Westinghouse Res. Lab. Sci. Paper 6-41210-1-P1 (1960). 4. V. A. Sidorenko, At. Energ., 43, No. 5, 325 (1977). 5. D. M. Petrunin, E. D. Belyaeva, and I. L. Kireeva, Preprint of the Atomic Energy Institute, IAE-2519, Moscow (1975). 6. K-Fr. Potter, V. Riehn, and G. Suschowk, Kernenergie, 19, No. 4, 116 (1976). 7. V. V. Pobedin and V. D. Simonov, Kernenergie, 12, No. 3, 77 (1978). 413 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 FORMATION OF HYDROGEN IN THE RADIOLYSIS OF WATER VAPOR B. G. Dzantiev, A. N. Ermakov, UDC 541.15:621.039 and V. N. Popov Recently, in connection with the problem of hydrogen power, new economical ways of synthesizing hy- drogen based on water and mineral raw materials has been widely discussed in domestic and foreign litera- ture [1]. One of the possible ways of solving this problem may be the process of thermoradiation dehydroge- nation of water vapor (TRDW), using the thermal and radiation components of the power of a nuclear reactor. To evaluate the competitiveness of this method in comparison with others (heat cycles, electrolysis, etc.), data are needed on the yield of hydrogen in the radiolysis of water vapor, especially under conditions of high temperature and dose rate (T, J). The published data on the efficiency of radiation convertion of H20 ?112 are sparse [2] and cover narrow regions of variation of T and J. And yet, from data on the decomposition of H20 in the presence of organic additives [2], it follows that the yield of atomic hydrogen GH = 7 ? 100-1 eV. Then, under conditions excluding losses of hydrogen atoms, in principle it can reach values G(H2) GH 7. Evidently in this sense an increase in the temperature, when the contribution of the reaction H + H20 ?112 (activation energy Ei 1 eV) increases and the role of nonproductive recombination processes: H + OH, H + H, OH + OH, decreases, is favorable. In this work we present the results of experimental and theoretical investigations of the radiolysis of water vapor in a broad range of T and J. Irradiation of preliminarily purified distilled and degasified water was conducted on an U-12 pulsed accelerator in the temperature range 300-900?K accordingto the method described earlier [3, 4]. The radiation dose was monitored by chemical dosimetry (C2H4 ? H2) and by other methods. The temperature of the irradiated samples was recorded with a thermocouple. Hydrogen and oxygen were chromatographically analyzed. The values of G(H2) were determined according to the slopes of the kinetic curves. It was shown that in the absence of radiation influence, the formation of hydrogen by thermal and ther- mocatalytic means does not occur within the investigated temperature range. The initial radiation yield of H2 in the irradiation of water vapor is a sigmoid function of the temperature (see Fig. 1). At T 150?C, Gmin(H2) = 1.6 and does not depend on T. At T 350?C, Gm(H2) = 8 and also does not vary when the temperature is further increased. The transition from Gmin(H2) to Gmax (H2) occurs within a relative narrow temperature range (AT 150?C). The effective activation energy of the formation of H2, Eeff ?-? 2 kcal /mole; Eeff is not directly correlated with El, which is due to competition of the following processes: 1) H + H2O; 2) H + OH; 3) H + H; 4) OH + OH; and 5) H20?H2. The kinetic analysis of the radiolysis of water vapor in the linear region of the curves of formation of 112 can be performed within the framework of a two-radical model (H, OH) and the five equations indicated above. To estimate the efficiency of the decomposition of H2O as a function of T and J, it is useful to introduce the parameters and r, correspondingly equal to the ratio of the rates W of the reactions H + 1120 and H + OH, and to the concentration ratio [H] / [OH], into consideration: = w1/w2= k, [H20]/Ic,[0H]. For pure water vapors = 14/r ?14r, where 14 = ki/ k2; r = [H] / [OH]. Under these conditions n = [G(H2) ? 421/GH = + leg) /(1 + + 214); 4/2 = G5= 0.5. A family of curves G(H2) = f(T, J) for J = 1012-1020 eV/cm3 ? sec and T = 300-1000?K was obtained using functions of this kind. A comparison of the calculated curve and the experimental values indicates good agreement of the ex- perimental and theoretical functions G(H2) = f(T). The value G(H2) = 8 achieved in the work is of the order of G(H) and corresponds to ??=:20% conversion of the radiation energy to the desired channel of the reaction of 112 synthesis. However, this value cannot be considered the limit. In principle the yield of hydrogen can be in- creased by the conversion of OH radicals to atomic and, correspondingly, molecular hydrogen (selection of the Translated from Atomnaya Energiya, Vol. 46, No. 5, pp. 359-360, May, 1979. Original article sub- mitted September 1, 1978. 41.4 0038-531X/79/4605- 0414 $07.50 ?1979 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 (00 200 300 400 500 600 T,?C Fig. 1. Experimental dependence (0) of the radiation yield of hydrogen in the ir- radiation of water vapor on the tempera- ture at J = 1.3 1015 eV/cm3 sec and H2OP =- 760 mm Hg: - - -) theoretical curve of G(H2) = f(T) for the same dose rate; on in- set, calculated functions = .;(T, J). physicochemical parameters of radiolysis, introduction of converting additives X = NO, CO, etc.). In the latter case, the realization of a chain process is not excluded: H + H20? H2 + OH; OH + X ? XO + H. Another possibility of increasing G(H2) may be associated with a change in the primary spectrum of dissociative ioniza- tion of H2O molecules on account of charge transfer to water molecules from additions of substances with a high ionization potential (N2, He). The authors would like to thank V. A. Legasov for formulating the problem and for his interest in the work. LITERATURE CITED 1. V. A. Legasov, Priroda, 3, 3 (1973). 2. R. Dixon, Radiat. Res. Rev., 2, 237 (1970). 3. B. G. Dzantiev, V. N. Popov, and Yu. N. Smelova, Khim. Vys. Energ., 5, No. 1, 86 (1970). 4. V. I. Gol'danskii et al., At. Energ., 30, No. 3, 262 (1971). 415 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 INFORMATION THE 45TH MEETING OF THE SCIENTIFIC COUNCIL OF THE JOINT INSTITUTE FOR NUCLEAR RESEARCH V. G. Sadukovskii This meeting was held in January, 1979 in Dubna; the activities of the institute during 1978 were sur- veyed, along with the current and forward plans. The meeting was opened by the director of the institute, N. N. Bogolyubov, who outlined the work of the executive in implementing the decisions of the council. The directors of the individual laboratories also presented reports on recent researches and development studies carried out in 1978. The Laboratory of Theoretical Physics (report by D. I. Blokhintsev) has used the quasipotential approach in quantum field theory in examining corrections to the self-modeling behavior in high-energy large-angle scattering amplitudes. A parton picture of exclusive processes has been built up in quantum chromodynamics, and this picture is not a Feynman type. A detailed study has been made of the power-law behavior of the hadron formation cross section for large values of the transverse momentum. Hypotheses on the global duality of quark loops and resonance contributions to spectral sum rules have been used in calculating the electromag- netic radii of charged and neutral kaons along with the structural parameters of the corresponding semilepton decays. The results are in agreement with experiment. Chiral quantum field theory has been employed in completing a description of the major decays of meson octets. Calculations have been performed on the lepton and semilepton decays of D and F mesons. A computer program has been written for performing the Bogolyu- bov?Parasyuk R operation in scalar theories, i.e., the construction of renormalized-function coefficients for Feynman diagrams in the form of integrals with respect to parameters. A form of quantum electrodynamics has been devised in which the gauge transformations are dependent on a fundamental length. Radiation cor- rections have also been applied to deep inelastic scattering of neutrinos by nucleons, which are required for the joint Dubna?CERN experiment. In the area of nuclear theory, a microscopic approach has been devised for research on heavy-ion inter- actions. A mechanism has been examined for dissipation of the energy of the relative motion of particles, par- ticularly by the production of internal excitations of one-particle and collective types. The Pauli principle has been incorporated into the theory of collective nuclear oscillations, and a quasiparticle? phonon model has been employed, which indicates that corrections for giant resonances applied to the radiation widths of neutron resonances in spherical nuclei can produce good agreement with experiment for El and M1 transitions. The first exact expressions have also been derived for the Green's functions involved in the interactions of electrons with phonons and external electric fields; these have been used in kinetic equations for an elec- tron?phonon system. A general approach has been devised for researching channeling of light and heavy par- ticles in crystals, which employs techniques first devised for examining small systems interacting with ther- mostats. The High-Energy Laboratory (report by A. M. Baldin) has completed a research on elastic scattering of protons by protons, deuterons, and helium nuclei in joint Dubna? FNAL experiments on the 500-GeV ac- celerator in Batavia. In the experiment on forward K-meson scattering at electrons at 250 GeV, a result was obtained for the electromagnetic radius of the K meson. The NA-4 apparatus has been installed on the SPS-400 accelerator at CERN for joint Dubna?CERN ex- periments on deep inelastic scattering of muons by H, D, and C targets. Extensive checks have been per- formed on the equipment during adjustment and a start has been made on processing the beam data. The processing has been continued on data obtained in experiments with the Institute of High-Energy Physics accelerator at Protvino, which has been operated with the BIS-2 complex, the Ludmila system, and a 2-m propane chamber. Upper bounds have been defined for the partial cross sections for the formation of 17 systems that seem to be likely sources of charmed particles decaying to 2 or 3 charged particles. These estimates lie at the level of 0.1-1.3 ?barn. Researches have also been performed on the inclusive formation Translated from Atomnaya Energiya, Vol. 46, No. 5, pp. 36 1-364, May, 1979. 416 0038-531X/79/4605-0416$07.50 ?1979 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 of neutral particles and on invariant cross sections and mean 7r-meson and proton multiplicities, as well as on light isobars and antiisobars in antiproton?proton collisions. A test has been performed on scale invariance in multiplicity (KNO) and on Wrublewski's relation for multinucleon interactions of it mesons with carbon. The synchrophasotron at the Joint Institute for Nuclear Research has been used in an extensive pro- gram of research on relativistic nuclear physics; the DISK-2 system has been used with an 8.6-GeV/sec pro- ton beam in research on the high-order cumulative formation of pions, protons, deuterons, and tritons. The energy spectra of the cumulative particles are of exponential type for an emission angle of 1800 for various nuclei and the various curves are similar in shape. Indications have been obtained that superdense states oc- cur in research on dibaryon systems composed of A-hyperons and protons, particularly from research with the propane chamber used with a neutron beam of average momentum 7 GeV/sec. Studies have also been performed to improve the utilization of the synchrophasotron in physics experi- ments, which have involved upgrading the parameters. The carbon-nucleus flux has been raised to 2 ? 106 par- ticles /pulse, and this can now support parallel operation of two physics experiments. A second slow beam- extraction system has been installed for operation of 200-400 MeV/ nucleon, and ion radiography has been used with a helium-nucleus beam at 200 MeV/ nucleon. The researches for the nuclotron project and the storage system (UNIQ have involved the manufacture and detailed testing of five specimens of pulsed superconducting magnets. Measurements have been made on the energy deposition on irradiating a superconductor in an intense proton beam. New techniques developed in the laboratory have included the design of high-sensitivity detectors based on proportional chambers for the analysis of thin-layer radiochromatograms, the development of new electronic units for interfacing physics experiments to computers, and devices for data acquisition and processing. The Nuclear-Problems Laboratory (report by V. P. Dzhelepov) has conducted physics researches with the synchrocyclotron, and in particular has completed researches on a new phenomenon observed in the labo- ratory, viz., the resonant formation of a deuteron?deuteron /1-meson mesomolecule. A germanium?lithium y-ray spectrometer has been used with the n + 1H ?2D + y reaction to measure the deuteron binding energy with higher precision, and this has provided better values for the neutron rest mass and the mass difference between the proton and neutron. A new technique has also been developed that has provided a complete and consistent set of y-ray energy standards in the region of 2 MeV, which has reduced the systematic errors arising in previous indirect techniques, while also ensuring considerably improved reliability. Measurements have also been made on the polarization of the cumulative protons in the scattering of protons by carbon, which have indicated that it is impossible to explain the momentum and angular results via a mechanism involving a high-momentum component of the nucleon mOtion in 12C. Data from the MIS system have been processed to yield the semicoherent elastic-scattering cross sec- tions for pions of momentum 40 GeV/sec incident on carbon. Studies have also been made on double pion charge transfer at carbon and on the associative multiplicity occurring in the formation of 7r6 mesons in 7r?p interac- tions at 5 GeV/sec. These measurements have been performed with the 1-m propane chamber. In addition, measurements on the 7r?p 7r07r0n reaction at 270 GeV have been completed, and the experiments confirm the pion?pion interaction theory based on deviation from chiral symmetry in the strong interaction. An experi- ment has also been completed in which ?-mesoatom radiation has been used in determining the elemental com- positions of organs. Experiments under the YaSNAPP program have been performed, especially those con- cerned with neutron-deficient isotopes. Previous systematic studies with the spin system have been continued, especially with transition-region nuclides, by nuclear orientation at very low temperatures. Major results have also been obtained in various more technological aspects. A very large spectro- meter with streamer chambers (the RISK system) has been commissioned in the 70-GeV accelerator beam. Apparatus has been built for examining polarization effects in ecchange pion?proton scattering, which has included the commissioning of the world's largest polarized frozen-proton target for research on polarization effects at high energies. Tests have been completed on the beam from the Serpukhov accelerator for the first design of the Hyperon spectrometer system, which is intended for research on hypercharge-exchange pro- cesses in it and K meson beams. A new method has also been developed for researching the parameters char- acteristic of the superconducting state in metals by means of impurity-muon spin relaxation. The laboratory has also collaborated with the Institute of Nuclear Physics in Rez (Czechoslovakia) on the extraction of the beam from the U-120M accelerator without energy loss. A large volume of work has also been performed on upgrading the synchrocyclotron to a high-current phasotron. New types of units within the CAMAC standard have also been built. 417 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 The Nuclear-Reactions Laboratory (reports by G. N. Flerov and Yu. Ts. Oganesyan) has commissioned a a new accelerator (the U-400 4-m isochronous cyclotron) with many applications in nuclear physics, especially the synthesis of new heavy and superheavy elements. This cyclotron was built entirely within the institute with- in a very short period. In December, 1978 an intense beam of argon ions of energy 5 MeV/nucleon was pro- duced at the final accelerator radius. The main efforts of the laboratory in the research field have been concerned with the search for naturally occurring superheavy elements, synthesis of transuranium elements, and nuclear reaction mechanisms. Ex- periments have been performed on the concentration of a natural spontaneously fissile isotope. The concen- tration level so far attained provides a basis for detailed studies on the mass and decay. New data have also been obtained on the spontaneous fission of some isotopes of elements 105 and 106. Attempts have been made to synthesize element 108 in the 226R a + 48Ca and 208Pb + 58Fe reactions, and upper bounds for the reaction cross sections have been defined. Information has also been obtained on the characteristics of fission in heavy nuclei induced by a particles at energies near the height of the Coulomb barrier. The contributions from the symmetrical and unsymmetrical modes of fission have been distinguished, and it has been concluded that shell effects influence fission in weakly excited heavy nuclei. Researches have also been performed on quasimolec- ular spectra. A new method has been devised for elucidating the nature of the positrons arising in the colli- sions of heavy nuclei. Development studies have also been continued on the application of nuclear-physics methods. Workers from the institute have commissioned a new plant of high throughput for the production of nuclear filters. Also, the microtron in the laboratory has been used in devising methods of routine analysis for various types of ma- terial containing trace amounts of rarer elements. The Neutron-Physics Laboratory (report by I. M. Frank) has obtained evidence on the absolute value and energy trend for the neutron radiative-capture cross section of helium-3, as such data are of major importance for fundamental research on four-nucleon systems. The method developed in the laboratory has been used in early experiments on the isomeric shift of the neutron resonance in uranium-238 in various compounds. This technique has defined the change in the rms radius of the nucleus on excitation up to energies of about 6 MeV. Small-angle neutron scattering has also solved a problem in molecular biology, viz., the distance between antigen binding centers in an immunoglobulin molecule. Measurements also show that temperature and isotopic replacement of hydrogen have little effect on ultracold-neutron storage times, which has a bearing on the focus- ing of such neutrons in neutron-optics experiments. An energy diagram for the crystalline levels has also been devised for the PrNi5 intermetallide by means of inelastic neutron scattering. The IBR-2 pulsed reactor has also been commissioned, and careful measurements have been made on all parameters, which have been compared with calculated values. Preparations are far advanced for full-scale operation of the IBR-2, including completion of the installation of the sodium cooling system, many different pneumatic and vacuum tests on the sodium loops, etc. Considerable progress has also been made on the IBR-2 injector, which is an LIU-30 linear electron-induction accelerator. The injector part of the accelerator is being assembled and other equipment is being manufactured. Specialists from the institute and from member-coun- tries have also performed many different studies on the physics equipment needed for research with the IBR-2 and for equipment needed for general purposes in the measuring bay. The Laboratory of Computing Technique and Automatics (report by N. N. Govorun) has completed the experimental operation of the first network of terminals working into an ES1010 minicomputer and a BESM-6. A microcomputer has been built into a VDU processor, and a small batch of graphics VDUs is being built that employ a new storage CRT. Engineering work has also been completed on the interfacing of eight ES5061 units of total capacity 230 megabytes to a BESM-6, and extensive debugging of the associated software has already been performed. New electronic equipment has also been tested for the HPD system, together with six Camet panels for use in software-managed tracktracing. The real-time filtration system for the Spiral equipment has also been completed. A suite of base software has also been written for calibrating and managing the AELT- 2/160 sys- tem, which has also been interfaced to a CDC-6500 computer, and routine measurements have therefore been begun on photographs recorded with the MIS system, while trials have been begun on similar measurements with the RISK photographs. Software has also been written for data acquisition and hardware monitoring in the BIS-2 by means of an - ES1040 minicomputer, along with software for ion radiography and base software for the Dubna-CERN joint muon experiment. Specialists at the laboratory have devised a simple and efficient means of generating ap- plied-program packages for processing queries in a special language within the framework of the Hydra system, 418 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 Declassified and Approved For Release 2013/02/12 : CIA-RDP10-02196R000800010005-1 as well as software for processing two-dimensional spectra. Development work has also been continued on new methods of numerical solution for nonlinear problems in physics, particularly those related to the UNK project and the heavy-ion accelerator system (UKTI), in addition to simulation of processes in nuclear physics at relativistic energies and of nonlinear phenomena in field theory. Software has also been defined for calculations on resonant states within the framework of Schr5dinger's equation with a spherically symmetrical Saxon?Woods potential. The meeting also received reports on the state of developments in the UNK and UKTI projects, as well as the plans of the Division of New Acceleration Methods for 1979 (report by Yu. N. Denisov). Collaboration between Dubna and the Institute of High-Energy Physics over the UNK system has steadily extended on the basis of the agreed program. Collaboration between High-Energy Laboratory and the Division of New Acceler- ation Methods has ?hown that it is desirable that the cryostat system for the UNK should include jet (ejector) pumps employing liquid helium. Measurements have been made on the losses in the MO-09 superconducting magnets built at the Institute of High-Energy Physics, as well as on the losses in short specimens of super- conducting leads and cables used at that institute in models for magnetic components for the UNK. Measure- ments have also been made on the radiation heating in superconductors. A sui