Soviet Atomic Energy Vol. 47, No. 4

Body: Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 ISSN 0038-531X Russian Original Vol. 47, No. 4, October, 1979 rc April, 1980 SATEAZ 47(4) 791-878 (1979) SOVIET ATOMIC ENERGY ATOMHAR 3HEPr1411 (ATOMNAYA ENERGIYA) TRANSLATED FROM RUSSIAN CONSULTANTS BUREAU, NEW YORK Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved SOVIET ATomic. ENERGY ' Soviet Atomic Energy is abstracted or in- dexed in Chemical Abstracts,- Chemical Titles, ,Pollution, Abstracts, Science Re- search Abstracts, -Parts A and B, Safety Science Abstracts Journal, Current Con- tents, Energy Research Abstracts, and Engineering Index, For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Soviet Atomic Energy is a corr-to-cover translation. of Atomnaya thergiye, a,pulltication of the Academy of Sciences of the USSR. , 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 '-nd publication of he translation and helps to improve the quality of the' latter.. The translation began with the first issue of -the Russian journal. ? Editorial Board of Atornnaya Energiya: Editor: 0: D. Kazachkovskii Associate Editors:' N. A. Vlagiv-and N. N. Ponomarey-StePnoi Secretary: A. I. Artemov I. N. Goloyin V. I. ll'ichey V. E. Ivanov V. F. Kalinin PI L. Kirillov Yu. t. Koryakin A. Krasin E. V.'Kuloy B. N. Laskorin' V. V. MatveeV I. D. Morokhov A. A. Naumov A: S. Nikiforov A. S. Shtan' B. A. Siddrenko M. F. Troyanov E. I. Vorpb'ev Copyright ? 1980, Plenum Publishing Corporation. Soviet Atomic Energy partici- pates in the program of Copyright Clearance-Center; Inc. The appaarance of a code line at the bottom of the first page of an article in this journal indicates the copyright owner's consent that copies of the article may be made for personal or.. interim! use. However, this consent is.given on the condition that the copier pay the stated per-copy fee through the Copyright Clearance Center, Inc. for all copying not explicitly permitted by Sections 107 or 108 of the U.S. Copyright Law. 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Subscription (2 volumes per year) . Vols. 46 & 47: $147.50 per volume (6 Issues). Vols. 48 & 49: $167.50 per volume (6 Issues) Prices somewhat higher outside the United States. *- Single Issue: $50 Single Article: $7.50 CONSULTANTS BUREAU, NEW YORK AND LONDON 227 West 17th Street ,New YO1-k, New York 10011 Published monthly. Second-class postage-paid at Jamaica, New York 11431. Declassified and Approved For Release 2013/02/15 : CIA-RDP10-02196R0008000.20004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 SOVIET ATOMIC ENERGY A translation of Atomnaya Energiya April, 1980 Volume 47, Number 4 October, 1979 CONTENTS ARTICLES AND REVIEWS Current Problems of Radiation Ecology and Hygiene in Nuclear Power Engl./Russ. ? E. I. Voroblev, L. A. Win, V. A. Knizhnikov, and R. M. Aleksakhin 791 219 Accelerators for Industry and Medicine (Contemporary State and Prospects) ? V. A. Glukhikh 797 225 Analysis of the Reliability of Pipes and Pressure Vessels at Atomic Electric Power Plants ? A. I. Klemin and E. A. Shiverskii 804 230 Optimization of Nuclear Power System Integrated within COMECON ? S. Ya. Chernavskii, N. A. Trekhova, and Yu. I. Koryakin 808 234 Fuel Contribution to the Cost of Nuclear Power ? B. B. Baturov, S. V. Bryunin, A. D. Zhirnov, Yu. I. Koryakin, V. I. Pushkarev, and V. I. Rubin 812 237 Mathematical Model of the Optimization of the Structure of Nuclear Heat Sources ? V. P. Brailov, M. E. Voronkov, and V. M. Chakhovskii.- - ? .816 241 Operating Experience with Automatic Reactor-Power Control System ? at Obninsk Atomic Power Plant Employing Signals from In-Core Self-Powered Detectors ? M. G. Mitelt man, N. D. Rozenblyum, V. B. Tregubov, Yu. M. Shpiposkildi, and A. I. Shtyfurko 820 244 Fission Products as 7-Ray Sources ? E. S. Stariznyi, M. A. Markina,. ' and V. A. Cherkashin 824 247 Particle Loss in a Linear Proton Accelerator due to Random Errors in the Channel Focusing Parameters ? P. N. Ostroumov ? and A. P. Fateev 831 254 NEW BOOKS S. M. Gorodinskli. Methods of Individual Protection of Workers Handling Radioactive Material ? Reviewed by Yu. V. Sivintsev 837 259 LETTERS TO THE EDITOR Effect of 7-Radiation on the Detecting Properties of Lavsan Film S. P. Tret,yakova and T. I. Mamonova 839 261 Use of Californium Neutron Sources to Determine Basic Element-Salt Composition of Seawater under Natural Conditions ? E. M. Filippov ? 841 263 Efficiency of Nuclear-Fuel Utilization by Molten-Salt Converter Reactors ? V. M. Novikov and V. L. Blinkin ? 844 264 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 CONTENTS (continued) Gas-Chromatographic Examination of the Accumulation of 3H, 85Kr, and I33Xe in the Protective Gas, Sodium Coolant, and Constructional Materials of the BR-10 ? L. I. Moseev, N. N. Aristarkhov, I. A. Efimov, V. N. Pisktmov, V. I. Smolyakov, and S. I. Shkuro 847 266 Critical Temperature Rise in a Coolant in an Annular Channel ? Yu. S. Yur'ev and M. A. Vladimirov 849 268 Measurement of the Total NeutrOn Cross Section of 145Nd ? V. A. Anufriev, A. G. Kolesov, S.N.Nikol'skii, and V. A. Safonov 851 269 Wide-Range Fission Chamber for Control and Safety Systems of Nuclear Reactors ? E. K. Malyshev, V. G. Belozerov, and 0. I. Shchetinin 853 271 Radiochemical Detector of Low-Intensity Fast Neutrons ?I. R. Barabanov, V. N. Gavrin, G. T. Zatsepin, I. V. Orekhov, and E. A. Yanovich 856 273 Comparison of Calculations on a Standard Fast Reactor ? A. I. Voropaev, A. A. Van'kov, and A. M. Tsibulya 857 274 Effects of Coolant Input Parameters on the Thermohydraulic Characteristics of a Field Steam-Generating Tube ? P. L. Kirillov, S. I. Kondrat'ev, and V. A. Farafonov 858 275 New Atomizdat Books (Third Quarter of 1979) 860 276 ANNIVERSARIES Eightieth Birthday Anniversary of Academician Nikolai Antonovich Dollezhal' 861 277 Viktor Alekseevich Sidorenko 863 ?279 CONFERENCE, SEMINARS, AND SYMPOSIA Second European Nuclear Conference ? I. D. Rakitin 865 280 Soviet?French Seminar on Sodium?Water Steam Generators ? P. L. Kirillov 867 281 International Symposium on the Physics and Chemistry of Fission ? G. B. Yan'kov 869 282 Second International Conference on the Use of Nuclear Methods of Analysis in Analytical Chemistry ? V. P. Varvaritsa ? and Yu. F. Rodionov 870 283 Twenty-Eighth Session of the Scientific Committee of the United Nations on the Effect of Nuclear Radiation ? A. A. Moiseev 872 285 International Conference "Neutrino-79" ? A. A. Pomanskii 873 285 NEW BOOKS S. N. Kraitor. Dosimetry in the Case of Radiation Accidents ? Reviewed by G. V. Shishkin 876 287 The Russian press date (podpisano k pechati) of this issue was 9/24/1979. 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 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 CURRENT PROBLEMS OF RADIATION ECOLOGY AND HYGIENE IN NUCLEAR POWER E. I. Vorobtev, L. A. Il'in, UDC 539.12:577.3:613 V. A. Knizhnikov, and R. M. Aleksakhin The growing worldwide attention to problems of ecology and hygiene has been due to the fact that at the present state of the art in the development of production forces man has become one of the most powerful fac- tors with a global effect on the biosphere. According to some forecasts, maintenance of existing rates and tendencies in the development of economic activity can, by as early as the year 2000, create conditions un- favorable to human life on the entire planet [1, 2]. The principal source of this effect on the biosphere are the enterprises of the fuel energy cycle. The imperceptibility of the effect of ionizing radiation clearly induces man to treat radiation contamina- tion of the environment by nuclear power undertakings with much more caution than he does the usual ejections of combustion products from fossil fuels into the atmosphere. Meanwhile, the latter contain chemical sub- stances, capable of causing cancer and genetic damage, as well as natural radionuclides [3]. There are ob- jective grounds for concern in relation to possible harmful consequences from the development of nuclear power. The principal ones are due to the absence of information which would permit a quantitative compari- son of the detriment to health and the environment from one form of power or another. Radiation ecology and hygiene should help obtain the appropriate information. Papers published to date have assessed the risk from atomic power plants and from thermal powerplants operating on organic fuel (coal, oil, gas) to human health [4-6]. In this case, however, the discharges from the atomic plants are taken to include all the main dose-producing components whereas the discharges from the thermal plants are taken to include only some macrocomponents and natural radionuclides [7, 8]. The radiation risk was calculated according to the maximum possible effects whereas the risk from many known dangerous agents, including carcinogens, contained in the discharges from thermal plants were not taken into account at all. At the same time, it is extremely important to assess alternative energy sources from the point of view of the carcinogenic hazard [9]. Assessment of the possible harm from various forms of power to the environment and human health should not be confined to comparison of power plants. In assessing the detriment to the health one must take account of the following stages in the complete cycle and the corresponding effect [8]: prospecting for fuel ? industrial accidents; fuel extraction ? industrial accidents and chronic ailments; fuel treatment ? industrial accidents and some risk to public health; transportation of fuel ? accidents with some risk to public health; power generation ? risk to public health and industrial accidents; waste disposal? risk to public health and industrial accidents. If all of the elements of this scheme are taken into account, then in accordance with the concept of "min- imum-risk energy alternative" it is possible to compare the harmful consequences from the development of various forms of power and to determine those which are least hazardous to human life and health. It is a similar matter with assessment of the nuclear and alternative forms of power from the point of view of their impact on the environment. An important area of research by radiation ecologists at the present time is unquestionably that of study- ing the migration of radionuclides under natural conditions from tailings and from fertilizers which can be ob- tained as a by-product during the production of nuclear fuel. Translated from Atomnaya Energiya, Vol. 47, No. 4, pp. 219-225, October, 1979. Original article sub- mitted May 15, 1979. 0038-531X/79/4704-0791$07.50 0 1980 Plenum Publishing Corporation 791 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 This research is a joint task for radiation ecologists and hygienists since the final goal should be to develop standards designed to limit the entry of radionuclides into the human organism. One of the main problems and fundamental questions of radioecology is that of scientifically substan- tiating allowable radiation burdens on nature. Research along these lines and elaboration of appropriate prac- tical recommendations are hindered by the necessity of taking account of all aspects of the value of nature and the harm ensuing from damage to it. It is extremely important above all to ascertain the role and relation of the limitations imposed on discharges by hygiene standards and ecological requirements. From the point of view of the use of the accumulated knowledge in the practice of designing and operating nuclear power enterprises, radiation ecology lags behind such a closely related discipline as radiation hygiene. As is known, radiation hygiene has developed a system of standards and regulations for the design, construc- tion, and operation of nuclear power installations to prevent harmful effects on the health of the personnel and the public. All hygiene standards regulating the contamination of the environment in the final account have one goal, i.e., of protecting the health of man. The applied aspects of radiation ecology have different objectives, i.e., preventing damage to the environment. It is logical to assume that whereas radiation-hygiene research has made it possible to develop legis- lative documents aimed at protecting human health, radioecological investigations should serve as a basis for appropriate legislative recommendations concerning environmental protection. As is known, hitherto there have not been any such recommendations of a legislative character. Hygiene standards do not take account of the "interests" of the environment as such. This situation should be attributed only to the "youthfulness" of radioecology. IAEA Publication No. 26 [10], which reflects present-day concepts of radiation protection, states that " ... radiation safety measures necessary for the protection of the human population will likely be suffi- cient to simultaneously protect all species of living organisms, although not necessarily all individuals of these species. The IAEA, therefore, assumes that if man is reliably protected against radiation, other species of living organisms will also be adequately protected." Thus, the cornerstone principle of setting standards for the radiation factor is asserted unambiguously, i.e., ensuring standards of radiation safety for man at the same time guarantees the radiation protection of living organisms In the environment and the biosphere as a whole. How valid and universal is this principle? The rational basis for the radiation-hygiene criteria for standards for the effect of ionizing changes con- sists of two premises, i.e., biological (man is the most radiation-sensitive living organism on earth) and social (the protection of the health of man is a problem of paramount importance). Since man is classified among the most radiation-sensitive components of the biosphere (at least, his radio-sensitivity is no less than that of other mammals), the introduction of standards concerning human irradiation indeed guarantees radiation pro- tection for all other living organisms if the effect of identical doses is considered. Thus the minimum absolute lethal dose (LD 100) is 450 rem. This indicator is also at the same level for other mammals which in respect of radiosensitivity stand above all other representatives of flora and fauna. The difference between the radio- sensitivity of man and many other living organisms is not so very significant. For example, LD 100 for pines and a number of other conifers is 1000-2000 rd and even lower in the more sensitive phases of development. Thus, the radioresistivity of conifers which constitute the basis of forests on our planet is higher than that of man by a factor of only 2 to 4. Many other species of living organisms responsible for the normal activity of various forms of natural communities of flora and fauna and playing an important role in the existence of a number of the principal ecosystems of the biosphere (particularly, forests) have "reserves" of radioresistivity which exceed the LD 100 for man by 5-20 times. As is known, under ordinary conditions when hygiene standards are established for the population account is taken of the genetic effects as well as late radiation effects, and not acute effects, i.e., values of roughly 1000-10,000 times smaller than LD 100. Observance of such standards automatically also guarantee protection of the ecosystem and the environment if radioactive discharges into the environment results in people and other living organisms being subjected to roughly equal irradiation. However, in actual fact in most cases the ab- sorbed doses for objects in the environment (plants, wild and domesticated animals, etc.) are substantially higher than for man under the same ecological conditions. In this situation it is not clear whether in all cases ensuring the radiation safety of man guarantees the radiation safety of some groups of living organisms. For example, the absorbed dose in some critical organs of cereal plants when a fresh mixture of fission products falls upon them in the critical phase (critical in relation to irradiation) of the ontogeny of the plants can be 10- 50 times higher (in extreme situations up to 100-250 times higher) than the dose of external y rays at a height of 1 m (radiation-hygiene criteria of irradiation) [11, 121. The difference between the absorbed doses in such objects of the natural environment as wild animals and man may be due to the different composition of their 792 Declassified and Approved For Release 2013/02/15 : CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 rations. In this respect the radioecological situation in the far north is characteristic. Here, under conditions when elk consume lichen, which is an efficient natural concentrator of radionuclides, and man eats the elk, the absorbed dose in bone tissue because of 90Sr from all sources in the case of the elk is 100 times higher than in the case of man. The difference is many times greater if one turns to those links in the ecosystem which are at low stages of evolutionary development (bacteria, fungi, yeasts, molds, algae, etc.). By virtue of the capability for con- centrating radionuclides, these objects may be subjected to irradiation with a dose rate which is thousands, and not tens of- hundreds, of times greater than in man in the same region. Such situations are most likely to arise when radionuclides fall into ponds, especially cooling ponds of atomic power plants, since the rise in the water temperature is conductive to more intensive absorption of radionuclides by practically all hydrobionts [13]. Thus, it can be concluded that, on the one hand, man is more sensitive to irradiation than are other living objects but, on the other hand, when radioactive substances enter the environment more living objects are sub- jected to irradiation with a much higher dose rate than is man. With observance of hygiene standards living objects in nature will not be protected if the ratio of the radioresistivities of those objects and man (according to the indicators assumed in the hygiene standards) is lower than the ratio of the real dose burdens on these objects and man under the given contamination of the environment; EDnat/PDman< RDnat/RDman, where EDnat is the endurable (harmless) dose of radiation of --- the natural object, PDman is the permissible dose (radiation-hygiene standard) of irradiation of man, and RDnat and RDman are the real doses of radiation of the natural object and man, respectively, in the given situation. Above we gave data on the comparative radioresistivity of man and natural objects according to LD 100, applicable for extreme situations. The hygiene standards limiting the radiation contamination of the environ- ment proceed from small doses of chronic irradiation, comparable with the doses from natural background. These standards were designed to prevent (limit) such late stochastic effects as an increased incidence of can- cer and genetic damage [10]. In accordance with present concepts, underlying these forms of pathology is damage at the molecular level (in the cell genome) which, if the repair and reproduction mechanisms are not actuated, results in the corresponding somatic (cancer) or genetic ailment. Thus, in order to approach the estimation of the comparative radiosensitivity of man and other living objects, not according to acute lethal effects but with account for parameters assumed in the hygiene standards, it is necessary to compare doses which cause in man effects taken into account in the elaboration of the hygiene standards and the level of doses causing undesirable effects in living nature and its ecosystems. Radiation doses capable of disrupting regenera- tion processes and thus facilitating the development of injury at various levels of biological integration, given in Table 1. It must be emphasized that the hygiene standards, as follows from the concept of a no-threshold char- acter and linearity, adopted by the IAEA [10] in essence regulate damage at the molecular level proceeding from the premise at permissible doses the protective mechanisms acting at the cellular and organisms levels are not suppressed and the frequency of damage to molecules is such that only in very rare cases does such damage escape elimination or repair and succeed in being realized through the formation of tumors or genetic damage. The objective of the hygiene standard is, to the extent possible, to protect each organism (individual); in protecting the environment, radioecology obviously can satisfy itself with protection at the population and biogeocenotic levels. The radical difference in the approach to protection of man and objects of nature, includ- ing farm and wild animals, is that hygiene is called upon, and strives, to protect each person from illness whereas ecology may not be interested in each individual but is concerned with protecting the population, the community. Thus, if for a group of reasons, including the limitedness of the food base, out of 100,000 fish eggs spawned in a body of water only 2000 individuals can develop and exist, then clearly there is no economic damage if, because of radiation, part of the fish eggs are destroyed or produce nonviable progeny since in this case 2000 individuals will still live in the body of water. When the above is taken into account, it becomes understandable why under real conditions disruptions in the sizes of populations and biogeocenotic changes are recorded only at irradiation doses running to hundreds and thousands of rads. If these data and those in Table 1 are taken into consideration and compared with the hygiene standards regulating the irradiation of limited population groups (0.5 rem/yr according to radiation safety standard NRB-76) [14], then it can be concluded that living objects can suffer harm according to the indicators listed in Table 1 only at doses which are two to three orders of magnitude higher than the hygiene standard. It would be inadmissible to rule out the possibility of such situations with overirradiation of any objects of the environment. It may be that in some situations with observance of the technical standards for 793 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 TABLE 1. Minimum Doses Acting on Mechanism of Repair of Radiation Damage at Various Levels of Biological Integration Level Regeneration mechanism and path Eff. min. dose, rd Units Molecular Cellular Organism Population Biogeocenotic Repair of biologically important molecules (e.g.,) repair of DNA by depletion-replacement; photo- reactivation, postreplicative repair) Amplification of processes of cell after the death of the radiosensitive part of the cell population Repair of activity of individual systems of organ- ism, leading to the complete regeneration of the organism, slowing down of some processes and amplification of others, ensuring complete re- generation Radioadaptation, radiation mutagenesis,elimina- tion of relatively radiosensitive individuals from the population, selection by radiosensitivity Homeostatic regulation of biocenotic processes under radiation, regeneration of individual com- ponents of biogenosis (regeneration of woody stage vegetatively when reproductive organs are dam- aged, regeneration of herbaceous plants from dormant buds, etc.), the assembly of regenerative reactions in components of biogenoceses after un- even irradiation. > 10 > 20 > 50 > 200 radioactive emission and discharges into the environment radiation protection of living objects cannot be guaranteed. It must be deemed desirable to develop and introduce radioecological criteria for standardizing the radi- ation factor to supplement generally accepted radiation-hygiene standards. It may be that in certain situations the radioecological standards will be more stringent than are the radiation-hygiene standards, e.g., in situations when emissions and discharges of radioactive substances may reach the territories of national parks or game refuges. It is possible that nuclides of biogenic elements (e.g., 3H, L) will accumulate far from the point of discharge in quantities capable of leading in the final account to such changes in those systems that major economic or other consequences might ensue (e.g., a change in the food chains in the ocean, acceleration of mutation processes in pathogenic viruses and bacteria, etc.). Unfortunately, present-day radioecology is still far removed from being able to present an orderly sys- tem of quantitative criteria of permissible dose burdens as has already been done in radiation hygeine for man. This is due primarily to the complexity and multiplicity of many years of ecological observations of the effect of small doses of radiation on natural ecosystems. As the first standardizing assumption for radioecological standardization of the radiation effect one could propose to use the concept of the "radioecological capacity of the environment." This term should be taken to mean the maximum permissible content of a radionuclide in a critical component of an ecosystem, a content such that the ecological harmony of the functioning of that eco- system is not disrupted (for national parks and game refuges) or such that changes which are undesirable from the economic or other points of view do not occur in the ecosystem. In order for this assumption to be rea- lized it is necessary to obtain concrete information providing a quantitative characterization of the radioeco- logical capacity of the main types of natural terrains, bodies of water, etc., which is the only thing that can put the problem of ecological standardization on a scientific footing. An important aspect of the problem under consideration is that of clearly defining the objective and necessary degree of protection of some living objects or other in a given concrete situation since it is perfectly clear that the "injury?benefit" principle which is proposed for use in elaborating radiation safety standards for man can be used with all the more justification in elaborating radioecological regulations. The elaboration of such regulations and quantitative estimates of the damage to nature because of nuclear power can be of great assistance in mapping out the course of develop- ment of the power industry in general, and nuclear power in particular. Some challenging problems confronting present-day hygiene have a direct bearing on the fate of energy programs. These problems are due to the fact that in such an important area as the effects of low doses, at 794 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 the level of the natural background, there is no unity of views as to problems of cardinal importance. Prac- tically no information at all is available for making quantitative estimates of the danger caused by chemical ,carcinogenic components of emissions from thermal power plants [3]. Problems existing in this area must be presented clearly since one solution or other for these problems may have a significant influence on our assessment on nuclear and alternative forms of energy as well as on the entire system of standards regulating emissions. Let us recall that present approaches to the regulation of dose burdens on man, as recommended by the IAEA and shared by other international organizations, proceed from the assumption that for stochastic effects (initiation of tumors and genetic damage) there is a linear thresholdless relation between the dose and the probability of the effect occurring [10, 15]. This approach makes it possible to assess the risk of stochastic effects under arbitrarily low doses and to establish standards for irradiation from the concept of acceptable risk. This approach served as the basis for nuclear powers to regulate irradiation of the population because of emissions from atomic power plants at an extremely low level, constituting only a small fraction of the fluctuations of the natural radiation background. As is known, direct data about the capability of dose burdens at the level of the natural background to cause cancer and genetic damage are not available. The carcinogenic effects of irradiation were revealed in experiments or as the result of epidemiological surveys only at irradiation doses exceeding the annual doses from the natural background by a factor of hundreds and thousands. In numerous experiments and ob- servations on animals and humans subjected to irradiation at a level of several tens of rem or less, no car- cinogenic effect of radiation was detected [15]. Some specialists, basing themselves on the factual data from such investigations, assume that there exists a threshold of the carcinogenic effect of radiation, It cannot be ruled out, however, that a dose which proves to be ineffective when acting on a limited number of individuals, under the conditions of action on a large population it will display its carcinogenic effectiveness and the "thres- hold" will turn out to be imaginary [16]. Simple calculations show that usually applicable methods of experi- ments on animals do not permit the problem of the threshold and effectiveness of low doses to be solved. Thus, with an irradiation dose of 0.1 rd (the mean annual dose of the natural radiation background) it may be expected that if the concept of no-threshold character and linearity is correct, various forms of tumors will appear with an incidence on the order of 105. Thus, in order to reveal the carcinogenic effectiveness of such a dose a group of animals numbering 100,000 is required. In actual fact, in view of the occurrence of spontaneous tumors in animals, for the detection of the effects of such low doses to be statistically reliable in comparison with a control there must be uniform test and control groups of animals with a much larger size; this makes it un- feasible to set up such studies and to solve the problem of whether or not a threshold exists on the basis of those studies. However, there are also other ways of investigating the problem of the threshold and effectiveness of low doses. Thus, an important argument in favor of the existence of a "practical threshold" is the reliable establishment that the latent period of formation of some tumors increases as the irradiation dose decreases. This permitted the assumption to be made that at low doses the latent period may exceed the maximum life- span [17]. This argument, however, can scarcely be taken into account when resolving the question of the threshold since the latent period of tumor formation is subject to considerable individual variations and with a reduction in the irradiation dose only the mean latent period increases. If in a small sample of animals at a given dose of irradiation tumors did not manage to develop, this does not mean that in a larger sample there will not be individuals which "manage" to give tumor growth. Thus, the given approach cannot serve as proof of the existence of a threshold. The opinion concerning the absence of risk at irradiation doses within the limits of the fluctuations in the natural background is also argued with concepts based on consideration of processes of cancer initiation [18]. It turns out that at the level of the cell and in the whole organism there are mechanisms directed at re- pairing damage inflicted by radiation as well as at eliminating cells which have degenerated into cancerous cells. It is noted that as the result of this, only at doses of 100 rd or higher, which are capable of affecting the protective mechanisms, do the probability of multiplication of cancerous cells and their transformation into a tumor begin to exceed the incidence of spontaneous cancer [18]. Unfortunately, such an approach, from which it follows that doses of less than 100 rd do not constitute a carcinogenic hazard, cannot be accepted as satisfactory since it does not explain, and does not take suitable account of, the stochastic nature of tumor diseases and other (genetic) damage whose source lies in mutation processes. It is known that at a dose of 100 rd, affecting the protective properties of the organism, and at much higher doses not all irradiated in- dividuals contract cancer. Conversely, it is perfectly clear that spontaneous cancer, which now causes the death of a large proportion of humans and animals, does not necessarily develop only with the protective mech- 795 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 anisms suppressed by radiation. If the point is, however, that the protective mechanism are suppressed in all cancer patients, it is natural to assume that they are suppressed not by irradiation (only for an insignificant part of them did the irradiation dose exceed 100 rd) but by some other factors inherent in real living conditions. If this is the case, then the carcinogenic effect of low irradiation doses cannot be ruled out against such a real background since the capability of even the lowest doses to cause mutations does not arouse any doubts in any- one. From the point of view of practical questions, numerous attempts to solve the problem of the threshold are stochastic in character and hardly have a direct bearing on the problem of setting standards for radiation effects. The point is that at the present time the mean individual radiation dose of the population of the USSR mainly from medical diagnostic procedures and the technogenic changed radiation background exceeds 250 mred/yr [19]. Inhabitants of large cities in industrially developed countries receive an annual whole-body dose of 0.3-0.5 rem and a dose of 1.0-1.2 rem to the lungs and 0.5-1 rem to the thyroid gland. It is not difficult to calculate that in 30-50 years of life these indicators may constitute doses which are very close to those which no one doubts are capable of increasing the incidence of cancer [15]. Since any effect subject to regulations is supplementary to that indicated, we assume that the IAEA position is substantiated; according to this position it is legitimate to calculate the risk from any arbitrarily small additional effect. Thus, in summarizing the problem of estimating the effectiveness of low doses, it should be pointed out that adoption of the existing concept of the linearity and nonthreshold character of the stochastic effects and the possibility of calculating the risk as a result of low doses on their basis is quite justified. There is a need of further research and new methodological approaches to refine the dose-effect relation in the range of doses comparable with the dose rate of the natural radiation background. Resolution of the question of the relative carcinogenic and genetic hazard of nuclear and alternative forms of energy depends to a certain degree on the carcinogenic effectiveness of the chemical agents present in emis- sions from thermal power plants operating on fossil fuel. At the present time, the mortality due to cancer in industrially developed countries is 1500 cases per year per million inhabitants. Using the concept of the no- threshold character and nonlinearity, we can estimate that because of the action of all sources of ionizing radi- ation, natural and artificial, out of one million p .rsons 20-30 may die, i.e., no more than 2% of the total number of deaths due to cancer. In the opinion of many specialists, about 80% of the total number of deaths due to can- cer are caused by chemical carcinogens, including those present in the emissions from power plants [3]. At the present time, it has been established experimentally (to some degree, this has also been observed for man) that some microcomponents of these emissions possess distinct carcinogenic properties for animals. These include 3,4-benzpyrene and other polycyclic aromatic hydrocarbons which are products of the incomplete com- bustion of fuel as well as a number of metals and their oxides, including nickel, chromium, nickel, iron, arsenic, and beryllium. Moreover, it has been found that a carcinogenic and cocarcinogenic effect is exerted by sulfur dioxide which is emitted into the atmosphere in hugh quantities by coal-fired power plants as well as by the products of oil refining. There is no direct proof that chemical carcinogens are responsible for a considerable part of the existing incidence of cancer, notwithstanding the importance of resolving this question. There are practically no regu- lations on the content of chemical carcinogens in the environment owing to the inadequate investigation of the hygienic aspects of carcinogenesis, especially the existence of a threshold of carcinogenic action by chemical substances. Since in the "nonradiation" areas of hygiene all standards have come to be established by proceed- ing from a threshold, the problem of setting standards for carcinogens in essence remains an open one [16, 17]. It is our contention that the discussion taking place on the existence or absence of a threshold in chemical carcinogens as in the case of ionizing radiation is more of academic rather than practical interest since in many places, if a threshold does exist for chemical carcinogens as it does for radiation, it has long been reached and surpassed. With the action of numerous chemical and radiation carcinogens characteristic of the present state of the environment, as a rule the action of the carcinogens combines and their effects add up. In other words, a pool of physical and chemical carcinogens which have reached threshold levels exists in the environ- ment. As a result of this, funda..?ental importance is taken on by the problems of quantitative ascertainment of the dose-effect relations which, unfortunately, have hitherto remained practically uninvestigated, even for long-known highly active carcinogens. Clearly, it is an extremely urgent and promising task to develop a chem- ical equivalent of the rem, which would permit the degree of risk from the action of various carcinogens to be expressed in comparable units [3, 5, 16]. It is also important to study the effects of the linked and combined action of carcinogenic and cocarcinogenics factors. The solution of these problems will help find optimal ways 796 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 of developing the power industry while preserving the natural environment and public health to the maximum extent. LITERATURE CITED 1. E. K. Fedorov, The Ecological Crisis and Social Progress [in Russian], Gidrometeoizdat, Leningrad (1977). 2. Yu. V. Svintsev, Nuclear Power and the Ecology [in Russian], Znanie, Moscow (1976). 3. K. Vohra, in: Proceedings of the Fourth International Congress IRPA, Paris (1977), Vol. 1, p. 181. 4. Yu. V. Svintsev and E. N. Teverovskii, At. Energ., 41, No. 4, 263 (1976). 5. A. Hull, Nucl. Safety, 12, No. 3, 185 (1971). 6. J. Martin et al., in: Environmenthl Aspects of Nuclear Power Stations, IAEA, Vienna (1971), p. 325. 7. Z. Jaworowski et al., in: Environmental Surveillance around Nuclear Installations, IAEA, Vienna (1974), Vol. 1, p. 403. 8. L. Lave, in: Proceedings of the Conference on Energy and Environment: a Risk?Benefit Approach, Birmingham (1975), p. 63. 9. L. A. Ilyin, V. A. Knizhnikov, and R. M. Barkhudarov, in: Proceedings of the Fourth International Con- gress IRPA, Paris (1977), Vol. 1, p. 189. 10: A. A. Moiseev (editor), Radiation Protection. Publication of IAEA Recommendations [Russian transla- tion], Atomizdat, Moscow (1978). 11. R. M. Aleksakhin, L. I. Boltneva, and I. M. Nazarov, Lesovedenie, No. 1, 35 (1972). 12. G. G. Ryabov, R. S. Prister, and V. A. Kal'chenko, Radiobiologiya, No. 16, 84 (1971). 13. D. I. Gusev et al., in: Problems of the Radioecology of Cooling Ponds of Atomic Power Plants [in Rus- sian], Ural Scientific Center, Academy of Sciences of the USSR, Sverdlovsk (1978), 13. 8. 14. Radiation Safety Standards NRB-76 [in Russian], Atomizdat, Moscow (1978). 15. Radiation Carcinogenesis in Man [in Russian], Paper NKDAR OON A/AC. 82/. 346 (1977). 16, V. A. Knizhnikov, Gig. Sanit., No. 3, 96 (1975). 17. H. Thomas, Science, 202, No. 4363, 37 (1978). 18. A. M. Kuzin, Radiobiologiya. 18, No. 3, 395 (1978). 19. E. I. Vorob'ev et al., At. Energ., 43, No. 5, 374 (1977). ACCELERATORS FOR INDUSTRY AND MEDICINE (CONTEMPORARY STATE AND PROSPECTS)* V. A. Glukhikh UDC 621.384.64+621.384.658 In recent years further significant expansion has occurred in the-use of charged-particle accelerators in radiation technology, radiography, activation analysis, and medicine, along With improvement of engineering- economic and operational indicators of industrial accelerators and the assimilation of new directions of their *This is the journal version of a lecture at the Third All-Union Conference on the Use of Charged-Particle Accelerators in the National Economy held in June of 1979 at Leningrad. More than 300 persons from more than 100 organizations of the Soviet Union and 40 foreign guests from nine countries participated in the con- ference. There were six working groups: Radiation engineering processes with the use of accelerators, ac- celerators for the national economy, the use of accelerators in medicine, radiography, activation analysis, and the formation and control of the parameters of the exit beam. About 200 lectures were delivered in three plenary and 15 section meetings. The conference showed that radiation technology utilizing accelerators has emerged onto a new qualitative level. If mainly accelerators designs were presented at the previous two con- ferences, lectures on testing the operation of radiation engineering accelerator facilities and their specific parameters and engineering-economic indicators predominated at this, the third, conference. This tendency was reflected in the plenary lecture of the president of the organizing committee of the conference, NUE FA Director V. A. Glukhikh, which is called to the attention of the readers. Translated from Atomnaya Energiya, Vol. 47, No. 4, pp. 225-230, October. 1979. 0038-531X/79/4704-0797$07.50 0 1980 Plenum Publishing Corporation 797 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 2,5 2,0 1,5 1,0 1975 1977 1979 Fig. 1. Variation of the power of the electron accelerators installed in the industrial plants of (1) the Soviet Union, (2) the USA, and (3) Japan. Fig. 2. Aurora II electron accelerator with individual protection. application. At present the annual extent of the production of radiation facilities operated abroad exceeds 1 billion dollars [1]; more than 90% of it occurs for facilities in which accelerators are used. About 230 ac- celerators have been installed in industrial plants in the USA, 35 in Japan [2], and more than 40 in the Soviet Union. The growth of their use can be characterized by the change in the cumulative installed capacity [2, 3], which has doubled in the last 3-4 years (Fig. l). As previously, the most widespread industrial radiation processes are the treatment by accelerated elec- trons of various polymer materials, the insulation of wires and cables, and films, rubber vulcanization, hard- ening of lacquers and paints, seeding polymerization, and sterilization [4]. However, notwithstanding an annual increase by ? 20%, the output of products and materials subjected to radiation processing still amounts to just a small fraction of the production volume of the corresponding branches of industry. This fact, together with the small compensation term of radiation engineering indicates the need for its broad introduction. The econ- omy of radiation processing of materials in comparison with processing by traditional methods also acquires continously greater meaning in connection with the increase in the cost of energy in the last few years. Significant successes have been achieved in the Soviet Union in the development and introduction of facili- ties with electron accelerators intended for the radiation modification of wires and cables with polyethylene in- sulation [5], the production of thermally seated products [6], the hardening of lacquer?paint coatings [7, 8], and radiation processing of fabrics and some other kinds of products and materials. New radiation processes have been developed, among which the use of electron accelerators for the protection of the environment is of special interest. One of the promising trends in this area is radiation purification of sewage, which permits giving up the traditional method of chlorination [9]. Preliminary economic evaluations of both methods [10] give com- parable results; however, it is important that the undesirable action of a large amount of chlorine on natural conditions in the adjacent locality is excluded in the case of the radiation method. But accelerators whose total beam power amounts to several tens of megawatts are required for the purification of the sewage of a large city in this manner. The use of powerful electron accelerators is also possible for the purification of the gas exhausts of heavy industrial plants and thermal electric power plants of the oxides of sulfur and nitro- gen contained in them. Results obtained with a test facility [11] permit concluding that in this case the neces- sary power of the electron beam for a plant with a capacity of 100 MW is about 4 MW, and the construction cost of such a facility is comparable to the cost of the usual type of purification equipment [10]. 798 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 C, dollars/kWh 0,8 1 2 46 _ ? 0,4 ? $5 0,2 50 100 150 P, kW Mg. 3. Dependence of the cost of production processing for accelerators of the RDI firm on power for an energy En MeV of 1) 0.5, 2) 1, 3, 4) 3, and 5) 1.5. Fig. 4. Aurora III high-voltage electron accelerator. In the majority of contemporary industrial radiation facilities high-voltage accelerators with an energy of 0.15-3 MeV are used, which permits processing materials and products up to 1.2 cm in thickness. For an energy up to 0.7 MeV accelerators with individual protection [7, 12] and with an extended cathode [13], which can be installed in ordinary production rooms along with the other engineering equipment of radiation facilities, have found widespread application (Fig. 2). The power of the largest of them, which can be discharged in series, has grown to 150 kW, and their reliability has simultaneously increased appreciably. As a result, the cost of processing materials with an electron beam (Fig. 3) has significantly decreased, and the prerequisites have been created for expansion of the incorporation of radiation technology [14]. New types of domestic acceler- ators (Fig. 4) with a beam power up to 50 kW have been developed [15, 16]. Evidently, one should consider the main trend in the development of the accelerators used in industrial radiation processes most recently to be the further increase of their power and reliability. The creation of facilities with a power of 1 MW and more under steady-state conditions already seems completely realistic [14, 17], although the solution of complex scientific and engineering problems is required for this to happen. However, the advisability of carrying out such developments is determined in the first place by the economic indicators of the corresponding energy-consuming radiation processes [10, 18] in comparison with the tradi- tional methods of production of this or the other product. At the same time the electron beam power of 50- 150 kW already achieved in many cases is sufficient due to the limited productivity of the other units of the technological process. Therefore an important direction in the refinement of industrial accelerators is also improvement of the engineering-economic indicators due to optimization of structural and layout solutions, reduction in the consumption of material, increase in reliability, and automrtion of control. The introduction of activation analysis directly in industrial plants deserves attention. One of the effec- tive uses in the analysis of the fluorine content in feed phosphates in the chemical industry with the use of an NG-150 neutron generator [19]. Along with neutron-activation analysis, analysis with the use of photonuclear reactions has received development. One can realize the high selectivity, rapidity, and representativeness 799 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Fig. 5. Control console of a laboratory for rapid analy- sis at a mining reprocessing complex. Fig. 6. Model of a transportable linear accelerator for activation analysis of ores in their natural state: 1)ther- mostatic control system; 2) shf generator modulator; 3) apparatus for shifting the accelerator; 4) electron accel- erator; 5) electron conductor; and 6) target. intrinsic to the method only with a sufficiently intense flux of bremsstrahlung, due to the relatively small inter- action cross section of the radiation with matter. Such fluxes are produced by linear waveguide accelerators [20]. A laboratory for rapid analysis of ores for gold and accompanying elements has been created at a mining _reprocessing complex with the use of the LUE-15A and LUE-8-5A developed at the D. V. Efremov NIIE FA [21] (Mg. 5). The accelerators are steady-state, and the ore samples selected for analysis are delivered to the laboratory. But such laborious operations as sample selection, indexing, and wrapping are maintained. There- fore, the analysis of ores in their natural state deserves attention, since it would thus be possible not only to eliminate the operations listed but also to increase the sensitivity and rapidity of the analysis. A possible ver- sion of such an accelerator is shown in Fig. 6. The accelerator is rigidly attached to an electron conductor and a target apparatus; variation of the insertion depth of the target into the hole is achieved by variation of the lift height relative to the surface of the earth. The equipment is arranged in 2-3 automatic machines. The alternative of an accelerator inserted into the hole is possible. However, the creation of a special com- pact shf generator must precede its development. 800 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Fig. 7 up 511 100 150 Steel thickness, mm Fig. 8 Fig. 7. LUE-15-15000D accelerator?flaw detector in the process of assembly in the x-ray room. ? Fig. 8. Sensitivity of the x-ray television method for an electron energy of 5 (1, 3) and 10 MeV (2, 4) without the memory unit (1, 2) and with it (3, 4). Interest has grown in accelerator?flaw detectors in connection with the development in this country of atomic power machine construction. 'Just as abroad,-flaw detectors based on linear waveguide accelerators have found wide application, which is due to the high increase in energy and the simplicity of beam entry and exit. The LUE-5-500D and LUE-15-15000D accelerator?flaw detectors have been developed in recent years [22], and the first batch of them has been prepared for the Izhorsk Factory Industrial Union and for Atommash (Fig. 7). The LUE-500D, which permits controlling a product made out of steel with a thickness up to 350 mm [23], will find the widest distribution, since the thickness of the majority of products does not exceed this value. Its parameters meet contemporary requirements. It is proposed to improve the flaw detector as a whole in the future. In particular, it is possible to increase the efficiency of some control operations of products of atomic power machine construction by virtue of the use of panoramic radioscopy. One should note that the possibilities of the developed accelerator?flaw detectors have not been completely realized, the results of radioscopy are still recorded on x-ray film, and the setting up and processing occupy up to half of the total control time. The recording and documentation of control results are being improved in several ways. Encouraging results have been obtained with the use of an x-ray television setup with a memory unit. The sensitivity achieved in the experiments (Fig. 8) satisfies the requirements for the control of the products of atomic power machine con- struction [24]. Electron accelerators, mainly the linear waveguide type, have received widespread distribution in medi- cine for radiation therapy. According to the data of [25], up to 600 such accelerators were counted in the world in 1978, and their number is increasing annually. In the Soviet Union their use for radiation therapy has not yet become widespread. About 10 accelerators are in use so far, Investigations of a working model of the LUE-15M (Fig. 9), in which it is possible to accelerate electrons to 20 MeV [26], have been completed. Based on this model, a pilot model of an accelerator, the LUE-15ME [27], with programmed control has been developed for radiation therapy. An integrated radiation head has been installed in it, which permits irradiating both with photons and with accelerated electrons. According to its parameters, it meets the requirements of the Inter- national Electrical Engineering Commission. It is possible with the aid of such an accelerator to treat more than 50% of the types of cancers. The cancer clinics of our country and the member-nations of the COMECON will be equipped with accelerators of this design. Development has begun on a medical accelerator for an en- ergy of accelerated electrons up to 40 MeV for cancer research centers. The use of protons beams in radiation therapy is known. According to the published data, more than 2500 patients worldwide have undergone such treatment. The localities being irradiated are now rather large, and 801 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Fig. 9. Working model of the LUE-15M accelerator. Fig. 10. External view of the cyclotron for production of short-lived isotopes. they are constantly expanding. In the Soviet Union mediobiological investigations and clinical research with proton beams are carried out at the Joint Institute for Nuclear Research, the Institute of Theoretical and Ex- perimental Physics, and the Leningrad Institute of Nuclear Research, but on accelerators intended forphysics experiments and only adapted for medical purposes. NIIEFA, together with the institute of Theoretical and Experimental Physics, the Cancer Research Center of the Academy of Medical Sciences of the USSR, and other organizations, has begun the development of a multibooth complex using a proton synchrotron with hard focusing for energy up to 220 MeV and a beam intensity up to 1012 protons/sec. The complex is intended for clinical use (100 radiation sessions per day), diagnostic purposes (proton radiography), physicoengineering and medico- biological investigations directed towards expansion of the use of a proton beam in medicine and biology, as well as for the production of radionuclides for diagnostic purposes. Eight channels of the external beam will be in the complex with entry into five procedure rooms. A distinctive feature of medical accelerators consists of the fact that such radiation parameters as the size of the field, the strength of a dose, and the direction must be varied in the course of a radiation session according to a program specified by the physician. This fact leads to the necessity for the development of devices with whose help one can vary at a distance the radiation parameters and the program of the controlling computer. The accelerator should be equipped with a special platform for the patient with the necessary num- ber of degrees of freedom in order to alter the position of the patient in the course of the irradiation. Thus the contemporary medical accelerator is a complicated device saturated with electronics. One more promising trend in the application of charged-particle accelerators in medicine is the produc- tion of short-lived isotopes for the diagnosis of diseases. A special cyclotron has been developed for these purposes at the D. V. Efremov NUE FA (Fig. 10) [28, 29]. In order to provide a high productivity, the beam of protons accelerated to an energy of 25 MeV should reach 1.5 mA on the internal and 0.2 mA on the external target. The information presented at the conference indicates further quantitative and qualitative expansion in the use of charged-particle accelerators in various areas of activity and their continuously increasing influence 802 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 on the acceleration of the scientific-engineering process, the increase of labor productivity, and the improve- ment of the quality of manufacture output. LITERATURE CITED 1. J. Silverman, "Current status of radiation processing," 2nd Int. Meet. on Radiat. Process., Miami, Oct. 22-26, 1978. 2. S. Machi, "Industrial application of radiation processing in Japan," ibid. 3. Business Week, July 11, 1977. 4. K. Morganstern, "Radiation processing with electron beam accelerators (present and future application)," Lecture at the International Electrical Engineering Congress, Moscow, June 1977. 5. E. E. Finkel' and G. I. Meshchanov, "The contemporary state and prospects for expansion in the use of electron accelerators in the production of wires and cables," Abstracts of the Third All-Union Conference on the Use of Charged-Particle Accelerators in the National Economy [in Russian] Leningrad, July 26- 28, 1979, p. 55. 6. L. S. Aktabaeva et al., "The use of electron accelerators in connection with the production of thermally seated sleeves," ibid., p. 20. 7. B. I. Altbertinskii et al., "Testing the operation of RKhU with Aurora-type accelerators for hardening lacquer coatings," ibid., p. 16. 8. I. Yu. Babkin et al., "Radiation chemical section for electron chemical hardening of the lacquer coatings on details of television cabinets," ibid., p. 14. 9. Yu. A. Panin et al., "Distinctive features of the processes and facilities of the radiation purification of sewage with a beam of accelerated electrons," ibid., p. 62. 10. J. Trump et al., Prospects for High-Energy Electron Irradiation of Wastewater Liquid Residuals, IAEA- SM-194/302. 11. S. Machi et al., Radiat. Phys. Chemists., No. 9, 371 (1977). 12. V. V. Akulov et al., "The Elektron-ZM-1 accelerator and its subsequent modification," Ref. 5, p. 25. 13. S. Nablo, W. Frutiger, and A. Denholm, "Performance characteristics of large Aua electron acceler- ators," 1st int. Meet. on Radiat. Process., Puerto Rico, May 9-13, 1976. 14. M. Cleland, C. Thompson, and H. Malone, "The prospects for very high-power electron accelerators for processing bulk materials," 1st Int. Meet. on Radiat. Process., Puerto Rico, May 9-13, 1976. 15. R. A. Salimov, "The ELV-series accelerators - parameters and application," Ref. 5, p. 31. 16. B. I. APbertinskii et al., "Electron accelerator for radiation processing of cotton and synthetic fabrics," Ref. 5, p. 34. 17. B. I. Altbertinskii et al., "Prospects for the development of electron accelerators for energy-consuming productions," in: Transactions of the Second All-Union Conference on the Use of Charged-Particle Acceler- ators in the National Economy [in Russian], Leningrad, October 1-3, 1975. 18. V. A. Glukhikh et al., "Principles of the engineering embodiment of a radiation-chemical method for ob- taining Portland cement clinker," Tsement, No. 11, p. 9 (1976). 19. L. A. Smakhtin et al., "The use of an NG-150 neutron generator for organization of engineering control in industrial plants," Ref. 5, p. 185. 20. Yu. P. Vakhrushin et al., "Linear electron accelerators for activation analysis," in: Transactions of the Fifth All-Union Conference on Charged-Particle Accelerators [in Russian], Nauka, Moscow (1977). 21. V. A. Glukhikh et al., "Industrial y-ray activation laboratory for the analysis of ore samples for gold and accompanying elements," Ref. 5, p. 131. 22. V. A. Glukhikh, Yu. P. Vakhrushin, N. A. Prudnikov, and L. P. Fomin, "Linear accelerators-flaw de- tectors of the NUE FA for the nondisruptive control of an atomic electric power plant," At. Energ., 44, No. 3, 293 (1978). 23. Yu. P. Vakhrushin et al., "The LUE-5-500D linear accelerator-flaw detector," Ref. 5, p. 190. 24. V. G. Levchenko et al., "An investigation of the flaw detection sensitivity of a model of an x-ray television unit with a linear accelerator-flaw detector," Ref. 5, p. 143. 25. W. Swanson, Radiation Parameters of Electron Linear Accelerators, SLAC-PUB-2092, March 1978. 26. Yu. P. Vakhrushin et al., "Physicotechnical and dosimetric parameters of the LUE-15M-medical linear electron accelerator," Ref. 5, p. 71. 27. A. A. Budtov et al., "The LUE-15ME medical linear electron accelerator with programmed control," ibid., p. 70. 28. P. V. Bogdanov et al., "Design parameters of the RITs Radiation Cyclotron," in: Transaction of the Sixth All-Union Conference on Charged-Particle Accelerators [in Russian], Annotation of lectures, Dubna (1978). 29. N. V. Akulova et al., "Structural characteristics of a cyclotron for production of radioisotopes," Ref. 5, p. 79. 803 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 ANALYSIS OF THE RELIABILITY OF PIPES AND PRESSURE VESSELS AT ATOMIC ELECTRIC POWER PLANTS A. I. Klemin and E. A. Shiverskii UDC 621.039.5.58:621.38.004.6 One of the most numerous and important components of the equipment of an atomic electric power plant are the pipes and pressure vessels. As domestic and foreign practice in the design and operation of atomic electric power plants (AEPP) shows, ruptures of large pipes, collectors, and vessels pose the greatest poten- tial radiation hazard among all equipment failures. A quantitative analysis of their reliability becomes an obligatory part of evaluating the reliability of a plant as a whole at the design stage. The results of an investi- gation of the reliability of the pipes and vessels of an AEPP are presented in this article. First let us formulate the concept of the failure of the elements under discussion. The failure of a pipe or pressure vessel is a loss in its efficiency due to depressurization to a level specified in the technical docu- mentation or the appearance of such irreversible changes (cracks, thinning of a wall with dimensions and nature specified in the technical documentation, etc.), which can then lead to depressurization and disabling of the pipe (vessel). The concepts of catastrophic and potential hazardous failure are often used for large pipes and vessels. Failures in which the rupture of a pipe (vessel) occurs in a short time (often practically instantaneously) are called catastrophic; the size of the defect for a pipe, e.g., is commensurable with its diameter, and rupture leads to significant damage. A catastrophic failure requires a rapid shutdown of the unit of the atomic electric power plant and the performance of extensive repair work. Potentially hazardous pipe and vessel failures are, as a rule, flaws in the basic metal and weld seams, looseness in mechanical joints, cracks of a definite size, local thinning of the walls (e.g., due to corrosion or erdsion), etc. Potentially hazardous failures should be eliminated opportunely, since in the course of operation part of the potentially hazardous failures can be- come the cause of catastrophic failures. Factors Which Determine the Reliability of Pipes and Vessels. The main factors which determine the reliability of the equipment items under discussion are given in Table 1, which is constructed on the basis of investigation and generalization of domestic and foreign testing of the maintenance of pipes and vessels at atomic and thermal electric power plants. The complexity of analysis of causes of failures of pipes and ves- sels lies in the fact that the factors listed often act together. In each case it is possible to speak of the domin- ation of several factors and of an insignificant effect of the rest. Situations in which it is possible to identify a single factor as the cause of a failure are relatively rare. Testing of the operation of pipes and vessels shows that failures which have occurred during the initial period are with great probability caused by factors of the first and second groups (see Table 1). Failures at the end of the term of service of an element are to a large extent related to factors of the third group; inter- mediate failures can be caused by factors of all groups. The relative contribution of individual groups of fac- tors to the unreliability of pipes is [1]: structural ? 16, engineering ? 28, and operational ? 56%. Failures occur most often in weld seams, bends, etc. For example, according to the data of [2], 54% of the pipe failures at AEPP have occurred in weld seams, 40% in the basic metal, and 6% in the threaded joints of pipes. Leaks precede the absolute majority of serious pipe and vessel failures. A practical conclusionfollows from this fact: It is possible with the help of regular inspections and control of potentially hazardous sections of pipes and vessels (weld seams and others) to increase to a certain extent their reliability, and what is es- pecially important, prevent catastrophic failures. The factors listed in Table 1 which act on pipes and vessels can cause the following basic mechanisms of their rupture (in order of importance): fatigue (low-cycle, high-cycle, thermal), corrosion under a voltage potential, creep corrosion, brittle fracture, viscous fracture, erosion, and others. Translated from Atomnaya Energiya, Vol. 47, No. 4, pp. 230-234, October, 1979. Original article sub- mitted October 23, 1978. 804 0038-531X/79/4704-0804$07.50 ?1980 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 TABLE 1. Classification of the Main Factors Which Determine the Reliability of Pipes and Vessels Structural Engineering Operational Choice of material Presence of strain condensers (number and nature) Nature of geometrical shape of the hy- draulic circuit of the coolant (presence of sharp bends, constrictions, and ex- pansions result in the origin of large- scale eddies in the coolant flow and vi- bration) Provision of compensation for thermal expansions Provision of flexibility (exclusion of ex- cessive liquid) of a pipe Nature of pipe mounting Adaptability to control and engineering inspection Quality of material Quality of preparation of pipes, bends, and cast elements Quality of welding Quality of preparation of sur- faces Effectiveness of outlet and in- take control Quality of transport Quality of assembly Loads: mechanical, thermal, and so on (steady-state and dynami- cal values and the nature of the loading) Action of contiguous medium (nature of the interaction: me- chanical, chemical, and others) Action of specific factors, includ- ing unplanned ones (irradiation, vibration, sediment, and so on) Amount and nature of control and technical service Departure of operating conditions from normal ones Errors in operation and servicing As a rule, the rupture mechanism is identified rather simply from the nature (external view) of the rup- ture. Such an analysis of failures with application to specific items and operating conditions is always neces- sary for reliable exposure of the dominant mechanisms and factors. Without this the development of effective measures for increasing the reliability of pipes and vessels and methods for predicting the level of their re- liability is impossible. Methods for Estimating the Reliability of Pipes and High-Pressure Vessels. One can isolate two groups of methods for determining the quantitative indicators of the reliability of these elements: From statistical data of operation or tests and under conditions of the absence (or insufficiency) of failure statistics. With respect to operational failures of a noncatastrophic nature (potentially hazardous failures) a pipe is considered as a repairable system whose elements are straight sections, bends, weld seams, and cast elements (elbows, T-joints, etc.) [3]. Calculation of the reliability is based on the statistics of failures of the correspond- ing elements in operation. In estimating the reliability indicators the assumption is usually used that in normal operations the reliability law of a pipe (vessel) is approximated by the exponential function. For each type of pipe (and vessel) it is suitable to calculate as the reliability indicators the following parameters of the flow of potentially hazardous failures: a) for straight sections b) for weld seams . c) for bends IT1 (per running meter) (02= ni5ITITD1 (per unit surface) u.)3= mw./TaDnw (per unit seam length) t04 = mb /Tit b (per bend) (1) (2) (4) Here mr, raw, nib are the number of failures on straight sections, weld seams, and bends of the pipt, respec- tively; T, working lifetimes of the pipe; / and D, length and outside diameter of the pipe; nb, number of bends in it; and nw, number of weld seams. In the general case, i.e., for a pipeline with pipes of several diameters, 0)2= mr /Ta D/j; (o3=mwIT3tN]Dj, where j is the number of the pipeline section of a single type or size. For estimates of the failure flow parameters it is advisable to determine the confidence intervals of L: co/ and con (a is the confidence coefficient), which characterize the accuracy of the statistical estimates. One can obtain the upper and lower confidence limits for the failure flow parameters from the formulas Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 (5) 805 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 (1)ui= co/r2; = (6) where ri and r2 are tabular coefficients which depend on m, 1, and a [4, 5]; the subscript i denotes "r", "w", or "b", respectively. In the absence of element failures during the working lifetime T the value of the confidence limit corn can be determined from the formula o = (1-V1 - a)/T, (7) where n is the number of scale units (running or square meters, bends). One can estimate from this same formula the upper confidence limit of a reliability indicator such as the intensity of the catastrophic failures (brittle fractures) of pipelines or vessels of an AEPP. Here the question is precisely the intensity and not the failure flow parameter, since one should consider the indicated elements as nonrestorable with respect to cata- strophic failures. When statistical information is absent or inadequate, the reliability of pipelines and pressure vessels can be estimated approximately with the aid of methods based on probability models describing the behavior of pipelines (vessels) under operating conditions and their depressurization or rupture. The "load-strength" model [6] can serve as an example of the simplest model. With its help the prob- ability of one random quantity (the load) exceeding another random quantity (the strength) of the material of a pipe or vessel is estimated. More complicated models are based on the application of methods for analysis of the stress state, the mechanics of rupture (taking the origin and development of cracks into account, and others. At present the majority of these methods of estimating reliability are in the development stage. An Estimate of the Actual Reliability of Pipes and Pressure Vessels of an AEPP According to Operational Data. it is necessary to have representative statistics of failures in order to obtain reliable estimates of the reliability indicators. Since the failure of a pipe or vessel is a rather rare event, additional operation of these elements is necessary to obtain the required amount of original data. Up to the present time the operational period of only some domestic AEPP is sufficient for obtaining reliable statistical data on the reliability of pipes and pressure vessels. Power units with a capacity of 1 million kilowatts with high-powered water-cooled channel (RBMK). and water-cooled-water moderated power (VVER) reactors are of the greatest interest for the development of nuclear power. A power unit with a VVER-1000 is in the construction stage. Power units with RBMK-1000 have up to 1978 been operated for about 11 reactor-years. Since there have been no failures of pipes and pres- sure vessels of the primary loop of these reactors, it is possible to make an upper estimate of the failure flow parameter for the pipe system of the primary loop of this type of reactor according to Eq. (6). It amounts to -10-5 h-1 per reactor. The first two units of the Novovoronezh AEPP with a capacity of 210 and 365 kW, respectively, have the longest period of operation of domestic power units with VVER. It amounts to 17 reactor-years. From the moment it came into operation until 1975 two failures of pipes of the primary loop were recorded in all. In accordance with this, the failure flow parameter of the pipe system of a single circulation branch of these re- actors is equal to -1.5 ? 10-8 h-1 per reactor. - In the interests of a more detailed analysis of the actual reliability of pipes and high-pressure vessels statistical information was collected at the first AEPP in the world at Obninsk, the Beloyarskaya AEPP, and an-AEPP in Dimitrovgrad with a VK-50 reactor. These plants have been operated for an extended period of _ time (the Obninsk plant - from 1954, the VK-50 - from 1965, and the Beloyarskaya plant - from 1964). As a result it has proven possible to collect failure statistics which can be processed by the procedure outlined in the previous section. The data at the first AEPP in the world were collected from the start of its operation through 1975 inclusively and at the Beloyarskaya and VK-50 sites - from the start of operations through 1978. The characteristics of the elements considered and the indicators- obtained for their reliability are given in Tables 2-4. The overall failure flow parameter for the main pipes of the primary loop is given in Table 2. The failure flow parameters per weld seam and per bend of these pipes are approximately equal and amount to 5 -10-811-1; the 80% confidence interval is (1-8) ? 10-811-1. Analysis of the operational data of the pipes and vessels of the VK-50, which is an experimental industrial facility, has shown that practically no failures of the elements noted have been observed from the time of its start-up. It is possible under these conditions to calculate an upper confidence limit for the failure flow param- 806 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 11 t TABLE 2. Characteristics and Failure Flow Parameters of Pipes and Pressure Vessels of the First AEPP in the World ? Equipment Material Pkgrefsiscunr , Te.cmp., 10-4?811-1 Main pipe! of the first loop, Dy = 1Kh18N9T 100 100-300 20,8 200 Individual pipes, Dy = 1Kh18N9T 100 230 0 200 Volume corn- 1Kh18119T 103 ____ 1,6 housingnstEconomizer 1Kh18N9T 100 (14)* 200 3,9 Steam super- heater Carbon steel 100 (13)* 230 24,0 Evaporator 1Kh18N9T 100 (14)* 200 2,4 *The pressure inside the housing is given in parentheses. TABLE 3. Characteristics and Upper 95% Con- fidence Limit for the Failure Flow Parameter of Vessels and Pipes of the VK-50 Equipment Temp., *C Pressure, kgficm2 ? Wu, 104 h-1 High-pressure separator 310 100 3,5 Low-pressure separator 241 35 3,5 Low-pressure preheater - 15 7,5 Deaerator tank 104 1,2 3,5 Pipe assembly 100-300 1-100 7,5 TABLE 4, Technical Characteristics and Reliability Indicators of the Pipes and High-Pres- sure Vessels of the Beloyarskaya AEPP Equipment Diam. and thick- ness of wall,(Di; Mtn Material Pressure, kgf/cm2 Temp ..0 Failure flow parameter overall straight section weld seam bend 10-6 11-1 18,8. 10-8 h-1 ? rn (o3; I'm, 10-8 h-1 ? rn (0; -8 ' 10 11-1 High-pressure (HP) pipe of 279X14 Kh18N9T 160 340 - 1,5 44,3 9,2 loop I 0,8-2,1 35,7-52,1 6,0-12,1 HP pipe of satur4ed steam 219x16 Kh18N9T 110 316 - 0 13,0 4,2 of loop I 0-1,6 5,4-19,4 0,9-6,8 Main steam pipe 279 x 15 12Khivy 95 510 - 0 27,8 59,0 0-0,9 19,4-35,6 46,1-71,1 HP supply pipe of loops I 245x18 St 20 ? 135 300 - 5,4 30,0 49,6 andll 2,2-8,1 19,5-39,5 38,3-59,8 Individual pipe 32x3 1Kh18M9T 145 330 - 0 0 ? 0 0-0,04 0-1,2 0,02 Drum separator 1600 x 92 16GNM 150 340 5,8 - - - 2,4-8,7 Evaporator 2000 x 70 18TS 110 316 8,0 - - - 4,9-10,7 HP preheater 1500x12 22K 12 290 7,2 ___ _ - 14,9-9,4 Hydraulic collector 273 x 28 1Kh18N9T 130 310 1,9 - - - 1,1-2,6 Collector of preheated steam 325x35 12KhMF 115 510 6 - - - 807 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 meter (see Table 3). The average value of the flow parameter and its lower confidence limit agree and are equal to zero. The characteristics of the pipes, pressure vessels, and collectors of the Beloyarskaya AEPP are presented in Table 4. There the 80% confidence interval -10.8 for the failure flow parameter is given. Analyzing the operational testing of the primary and secondary loops of the Beloyarskaya AEPP, as well as of the first AEPP in the world, one can note that the greatest part of the pipe and pressure vessel failures of these power units with channel reactors is related to the coolant flows in les'S important pipes of small diam- eters ?flaws, breaks in drainage, surge, and air lines, and at the sites of welding of resistance thermometer cases. A similar conclusion has been drawn in [2] with respect to an AEPP with light-water reactor vessels. It is noted there that 70% of the rejected pipes at the power plant have a diameter of 150 mm. The majority of the failures in individual pipes of the primary and secondary units of the Beloyarskaya AEPP are associated with leaks from the attachment points of disconnected equipment. -Flaws and cracks in weld seams have arisen, as a rule, in the case of increased vibration of the pipes, their insufficient compensation ability, or poor quality in making the weld seams, as well as corrosion. A crack in the region of a weld seam is a dangerous kind of defect in collectors. Such defects can result in the complete breaking away of pipes from collectors. It is significant that no serious failures of large pipes and high-pressure vessels have been observed at all the operational domestic AEPP. LITERATURE CITED 1. E. Kilsby, Nucl. Safety, 7, No. 2 (1965-1966). 2. ? S. Basin and E. Burns, Trans. Am. Nucl. Soc., 26 (1977). 3. A. I. Klemin, Engineering Probability Calculations in the Design of Nuclear Reactors [in Russian], Atomiz- dat, Moscow (1973). 4. - Ya. B. Shor, Statistical Methods of Analysis and Control of Quality and Reliability [in Russian], Soy. Radio, ? Moscow (1962). 5. Ya. B. Shor and F. I. Kuztmin, Tables for the Analysis and Control of Reliability [in Russian], Soy. Radio, - Moscow (1968). 6. A. I. Aristov and V. S. Borisenko, Evaluation of the Reliability of Mechanical Systems [in Russian], Znanie, ? Moscow (1972). OPTIMIZATION OF NUCLEAR POWER SYSTEM INTEGRATED WITHIN COMECON S. Ya. Chernavskii, N. A. Trekhova, UDC 620.9.91 and Yu. I. Koryakin The development Of nuclear power in the COMECON member-countries will proceed along the lines of growing integrating tendencies. Precisely in the case of nuclear power integration can yield maximum effect. Integration of the fuel cycle will make it possible to step up the rate at which fast reactors are introduced and this will be of a decisive importance in the future. The prospects of an integrated system for the COMECON member-countries have been shown in [1]. Calculations were carried out on an optimization model of a nuclear power system, integrated with respect to fuel connections, embracing the COMECON member-countries. A minimum demand for natural uranium in the entire forecast period was adopted as the optimization criterion. It was found that because of the integration the fraction of fast breeder reactors could be increased by 8-12% for COMECON as a whole by the end of the forecase period while the consumption of natural uranium would be reduced by 13-14%. - Whereas in the qualitative respect the conclusions of [1] are industputable, their quantitative aspect re- quires refinement. The point is that the use of natural uranium as an optimization criterion in nuclear power optimization does not take account of such important characteristics as capital investment, the cost of mining and processing nuclear fuel, and therefore distorts the quantitive characteristics of the structure of the nuclear power industry. Translated from Atomnaya Energiya, Vol. 47, No. 4, pp. 234-236, October, 1979. Original article sub- mitted January 24, 1979. 808 0038-531X/79/4704-0808$07.50 01978 Plenum Publishing Corporation Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 In forecasting nuclear power development within national frameworks, as a rule use is made of the nor- malized expenditures. The use of normalized expenditures as the criterion within one country and minimum consumption of natural uranium as the criterion within COMECON leads to contradictory results. It is neces- sary, therefore, to develop methods taking account of the monetary costs of construction and operation of nu- clear energy plants and to consider them within the framework of COMECON. This goal has been set in the present paper. In our considerations we do not go into the territorial location of particular capacities of atomic power plants with fast or thermal reactors. We only resolve the problem of optimization of the structure of the nuclear power industry, i.e., the quantitative relation between fast and thermal reactors. In the development of a method of optimization according to a monetary criterion the basis adopted may be a nuclear power industry model consisting of system of linear balance equations reflecting the fuel con- nections among the atomic power plants in the COMECON member-countries and the links with the electric power systems of the countries. This model is given in [2] and for an integrated nuclear power system within the framework of COMECON it is written as Ax=b, xO. (1) Let us note that the models of the nuclear power industry for each country within the national framework are analogous to Eq. (1) in form. Let us consider the set S of countries and let us assume, as was done in [2], that the objective of each country is to minimize the total normalized expenditures for the development of a national power system for an assumed rate of growth. For each country these expenditures are calculated in the national currency. In accordance with this, we shall assume that the i-th country strives to develop its nuclear power system so that C'tx 1=1, 2, ..., S, (2) where C't is the vector of normalized expenditures of the i-th country (in the national currency) and x is the strategy for the development of a nuclear power system. Actual accounting practice between COMECON member-countries employs a monetary unit called a con- version ruble. It is natural to use this unit in the present problem as well, If the factor for conversion from the currency of the i-th country to the con'version ruble is denoted by at, then the vector of specific normalized expenditures by the i-th country, expressed in conversion rubles, is calculated as Ci =atC't and S functionals of the integrated nuclear power system can be written as Cix-0- min, i=1, 2, ..., S. (3) Thus, the problem of finding the optimal strategy for the development of an integrated nuclear power system is formulated as follows: On the set (1) find the set of optimal strategies which satisfy conditions (3). This problem is one of optimizing a system of linear constraints with a vectorial linear criterion. The optimal set of strategies satisfying the conditions of the problem formulated is, as is known, a Pareto set. At the same time, in most known methods of solving problems with a vectorial criterion or, as they are also called, multicriteria problems, this set is not determined. Let us consider two such methods employed in practical problems: The method of a leading objective function and the step-by-step method. The method of a leading objective function [3] envisages optimization of the problem according to an ob- jective function. Each of the remaining objective functions, along with the limiting value given for it, are in- cluded as an additional inequality in the model of the system. Application of this method presumes that one of the criteria of the problem dominates over the others and, moreover, requires additional data about the possible range of values of the criteria incorporated into the model in the form of constraints. All of this precludes the use of the given method in the problem of optimizing the nuclear power industry within the framework of COMECON. The step-by-step method [4] consists in the following. Let all the criteria be arranged in order of de- creasing importance; fi, f2 fs. We shall assume that all of them should be reduced to their minimum value. The algorithm for finding a compromise solution is as follows. First, find the optimal value with re- spect to one criterion, fi. Then, denote some "step" Aft by which the value of the given criterion can be in- creased so as to obtain a better result for the next most important criterion, f2. Next, we find the optimal solution for criterion f2 with the subsidiary constraint (4) 809 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 where fl) is the optimal value of criterion fl. Then, we once again begin step Af2, which determines the devi- ation from the optimal value of the second criterion obtained in solving this problem; this is done to subse- quently obtain the optimal solution for fs, etc. As is seen, this method also assumes that the criteria are of unetren importance and hence thie makes the application of this method in the given concrete problem inappropriate as Well. How, then, should the formulated problem be solved? To begin wtth, let tig find strategies which are Pareto-optimal. The strategies entering Into the Pareto set are determined as follows. The strategy XpdOe not belong to the Pareto set if in the set (1) there is a strategy xp such that the relation urnax). Their number is umax fit a) = No ? N (E)? No [II? P (u, (24) where No is the number of particles at the initial time =0. For coherent pertubations, (24) can be integrated exactly. By substituting (18) for P and realizing that P (u, )du= P(y, )dy, we obtain n (E)-- N (D =1? C "r sAl:) exp No If P (u, is given by (21), the fraction of particles lost is ' 1 n () = 1 ? 5 Po (y') (LI ( y? dy' , VE where cro (a) -= e-t212 dt is the probability integral. For the case described by the distribution function (23), n (t) a ? ? D2- ..- 4oky if. 1? (? ? / lu rT I eh (-v-1/1??11 JJ To calculate we will assume that the errors (and consequently Au) are independent and equally probable at various periods. In this case taking into account that AT =1, we obtain NF dt Au 2 ATI Au iv_ J u max urnax umax where NF is the number of focusing periods. It is then evident that is completely defined if the mean in- crease per period of the square of the amplitude, Au, is known. Thus, knowing the dependence of on the error in the focusing channel and the initial amplitude distribu- tion of the particles, we can use (25)-(27) to determine the beam loss over the entire length of the accelerator. Furthermore, with the help of (18), (21) and (23) we can calculate how the particle amplitude distribution changes. In particular, it is clear that the beam will be well spread in the process of acceleration, and the so-called halo will appear, leading to a particle loss. Figure 1 shows the numerically calculated particle loss in the linear accelerator at the Institute for Nuclear Research, Academy of Science of the USSR, and at Los Alamos (LAMPF, U.S.A.). Curves 1-3 were calculated according to (21) assuming the presence of errors due to the random rotation of the axis of the quadrupole lenses. We further assume that the geometrical parameters of the channel (aperture, relative length of the lens, etc.) do not change along the accelerator. It is clear from the curves that the requirement of minimal particle loss (at the 10-5 level) leads to additional limitations on the parameters of the injected beam (specifically, on the initial distribution of particles in the phase volume). By comparing the focusing structure of the accelerators at the Institute for Nuclear Research and at Los Alamos, we can conclude that with a suitable choice of channel parameters and alignment tolerance, it is possible to decrease the loss. Curve 4 in Fig. 1 was obtained by using (25), so that only the coherent oscillations were taken into account. It is evident that in the absence of corrections to the transverse position, the fraction of the particles lost may exceed 10-4. By comparing curves 1 and 4 we can see that loss due to coherent pertubation is substan- tially greater than loss caused by the random rotation of the lens axis. The level of "coherent loss" is 10-3 at the end of the accelerator, although in principle these losses can be eliminated, since the coherent errors are easily corrected. In the presence of systems correcting the beam position, the major contribution to particle loss will be associated with errors in the rotation of the lens axis, which are difficult or impossible to eliminate (or correct) in practice. Therefore their calculation is essential, particularly in the case of poor beam quality at the accelerator entrance. (25) (26) (27) 834 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 g(t) 10-4 10- 10.8 0,2 0,3 44 45 t Fig. 2 Fig. 1. Particle loss in the linear proton accelerator at the Institute for Nuclear Research (1, 2, 4) and at Los Alamos (3) for various beam radii at the accelerator entrance (radii shown beside curves). Fig. 2. particle loss as a function of for various beam radii at the ac- celerator entrance (radii shown beside curves). 20 40 60 m Fig. 3. Linear particle loss rate in the I-100 accelerator p- experiment [6]). The curve in Fig. 2 was calculated from (27) and corresponds to the errors of the lens gradient. For the accelerator considered, < 0.1 and the losses are insignificant. In Fig. 3 the dependence of particle loss rate in the I-100 accelerator [5] is shown, calculated with the help of our formulas. The initial distribution is gaussian: Po(s) ?exp (?s/so), with a parameter so =0.06 (a normalized emittance contains 86% of the par- ticles). For comparison, experimental points from [6] are shown. The agreement with experiment can be considered satisfactory if one considers that the basic contribution to the particle loss is the random pertuba- tion of the transverse oscillations. Our results may be confirmed by measurements on the 200-MeV linear injector-accelerator at the Brookhaven National Laboratory [7]. In this accelerator, at low energies the growth of the beam occurs mainly at the expense of the peripheral particles (compare with Fig. 3). This may be explained as the motion of space charge. At energies exceeding 10 MeV, the emittance grows at the ex- pense of changing particle distribution in the central region of the beam, in agreement with our assertions. Up to now we have discussed the determination of particle loss in the accelerator given certain errors (tolerances). One may, however, solve the inverse problem: Given an acceptable level of particle loss, de- termine the permissible tolerances in the parameters of the focusing channel. This problem is of special interest for strong-focusing linear accelerators (meson producers), in which beam loss cannot exceed 10-4- 835 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 10-5 because of the radiation danger. Requiring loss at the 10-5 level may necessitate high tolerances and the correction of the particle amplitude distribution along the accelerator (with the help, for example, of "scrapers"). The authors express their sincere thanks to S. K. Esin for interest in the work and valuable observa- tions. LITERATURE CITED 1. B. M. Bolotovskii and A. P. Fateev, Zh. Eksp. Teor. Fiz., 33, 304 (1957). 2. I. M. Kapchinskii, Particle Dynamics in Linear Resonant Accelerators [in Russian], Atomizdat, Moscow (1976). 3. S. M. Rytov, Introduction to Statistical Radiophysics. Random Events [in Russian], Nauka, Moscow (1976), Chap. 1. 4. N. N. Lebedev, Special Functions and Their Applications [in Russian], Gostekhteorizdat, Moscow (1953). 5. I. M. Kapchinskii, in: Proceedings of the International Conference on Accelerators [in Russian], Atom- izdat, Moscow (1964), p. 462. 6. V. N. Lebedev et al., in: Questions of Dosimetry and Radiation Protection [in Russian], No. 11, Atom- izdat, Moscow (1970), p. 77. 7. K. Batchelor, in: Proceedings of the Proton Linear Accelerator Conference, Los Alamos, October 10- 13, 1972, p. 12. 836 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 NEW BOOKS S. M. Gorodinskii METHODS OF INDIVIDUAL PROTECTION OF WORKERS HANDLING RADIOACTIVE MATERIAL* Reviewed by Yu. V. Sivintsev The development of the nuclear power industry and nuclear energy is impossible without exposing per- sonnel to radiation danger. The development of individual protection for respiratory organs and skin of workers engaged in operations with open radioactive materials played an important role in the solution of this problem. Such protection is most essential in uranium mines, where the major sources of radiation danger are gaseous radon and the radioactive aerosol products of its decay. Another exceptionally important area of the use of such means is the clean-up of the aftereffects of a radiation accident. A series of investigations begun in the 1950s is successfully continuing in our country under the directorship of S. M. Gorodinskii. This serves as the basis for the publication of a new edition of the book reviewed here. After a short initial chapter introducing the problem, a section follows which is illustrated with investi- gations of materials designed to be used for constructing individual methods of radiation protection. A success- ful choice of a model solution containing "Sr, 144Ce, R4 --Cs, and 196Ru (the most diffusive elements among fission products) allowed the evaluation of the shielding effectiveness of polymeric materials (in particular films) and rubber-based materials. Due to the nonreproducibility of results for 95Zr +95Nb and "Co, these were excluded from the model solution. The gist of this section is the new principle for improving the shielding properties of polymeric materials by introducing a "sweated out" addition to such materials, formed on the surface of a self-renewing layer. The theme of Chap. 3 and 4 is the methods of physiologic-hygienic evaluation and the investigation of effective means for individual protection. The appropriateness of including these sections in the book is convincingly demonstrated by the author. As a rule, the use of such methods, especially insulated suits, will cause the accumulation or loss of heat in the body and, as a consequence, considerably physiological changes which lead to a reduction of physical and mental efficiency. Investigations done under the guidance of S. M. Gorodinskii allowed a determination of the optimal parameters of the microclimate in the space beneath the suit. In the last two sections the reader will find information on the design and investigation of insulated suits for use in remodeling and accident work in an environment of radioactive pollution, as well as informa- tion about systems for protecting respiratory organs during work with radioactive substances. Chapters 7 through 9 concentrate on information about working clothes, gloves, and working shoes. The book concludes with a section about shielding as a means of protection, appropriate tabular supplements, and a large list of references. A small subject index makes the book easy to use. In every chapter the author describes the investigative methods and generalizes the results of the com- prehensive and lengthy experimental work (as a rule, this information is presented in compact tables and histo- grams) . Especially interesting is the section on protecting the respiratory organs, a problem whichhas caused many difficulties. During the 1930s the Hungarian scientist Brezina aphoristically formulated the essence of the problem: "A good respirator does not allow breathing, but a respirator which allows breathing affords poor protection." In 1955-1956, I. V. Petryanov, S. M. Gorodinskii, S. N. Shatskii and P. N. Basamov worked out a new scheme for a valveless respirator on the basis of calculations and experimental models. This served as the basis for the creation of the "Petal", in which a unique natural filter, FP, was used. Today this respira- tor is manufactured by the millions every year (p. 185). No less essential results are seen in other areas of individual protection. We see, for example, that the protective effectiveness is 99.998% for the pneumomark LIZ-Z in uranium mines. Unfortunately, in one of the most important places in the text there is an annoying misprint: In the final Table 23 (p. 163) the protective effectiveness of the complete set LG-5 is given as three orders of magnitude too small. Basically the book is lively and interesting; most of the important sections are well illustrated. It shows the frontiers which Soviet scientists study in the area of radiation hygiene and physiology. However, several *Third edition, revised and enlarged, Atomizdat, Moscow (1979), 296 pp., 3 rubles 40 kopecks. Translated from Atomnaya Energiya, Vol. 37, No. 4, p. 259, October, 1979. 0038-531X/79/4704-0837$07.50 ?1980 Plenum Publishing Corporation 837 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 sections of the monograph are not free from a careless style and terminology: On pages 161 and 239 we see special medical terms without the necessary interpretation of their meanings; Chap. 10 is written in a less lively style than others. In conclusion we will mention the emblem illustration on the jacket of the book. A knight in "armor" with a shield wards off the blow" from a beam of radiation. ? The Illustration symbolizes the main idea of the monograph: Personnel of the nuclear power industry must be protected from danger. The success of the book is due largely to the author ? S. M. Gorodinskii, recipient of the Lenin prize, Doctor of Medical Sciences. 8:18 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 LETTERS TO THE EDITOR EFFECT OF y RADIATION ON THE DETECTING PROPERTIES OF LAVSAN FILM S. P. Tret tyakova and T. I. Mamonova UDC 535.1.074 Since polyethylene terephthalate (Lavsan) can record the passage of heavy charged particles, it can be used as a detector in physical and cosmic experiments, and to produce nuclear filters [1]. After bombardment with ions of various kinds the detecting properties can be changed by electromagnetic radiation [2, 3]. We have investigated the effect of y radiation on the properties of Lavsan film of domestic manufacture under various exposure conditions. Films 10 and 50 pm in thickness were bombarded with a flux of 105-108 xenon and argon ions per cm2 at the U-300 cyclotron of the JINR Laboratory of Nuclear Reactions. The energies of the xenon and argon ions were 0.75 and 1.5-7.6 MeV/nucleon, and the specific energy losses were 80 and 26.0-12.5 MeV ? cm2/mg, re- spectively. Bombardment at angles of 30, 45, and 90? permitted a study not only of the etching rate of the polymer damaged by an ion, but also the shape of the channels of the particle tracks. Films were exposed to doses of 5 ? 103-2 108 rad of y radiation from 137Cs. Film samples which had been bombarded with ions, and samples which had not, were divided into three groups; The first and second groups were exposed to y radiation in air and in a vacuum (10'3-10-4 mm Hg); the third group was not exposed to y radiation. The spec- trometric characteristics were photographed, and the kinetics and selectivity of the etching of the film samples were studied. A study of the spectral characteristics of Lavsan showed that the exposure of Lavsan film to y radiation in air increased the absorption of light in the wavelength range from 3150 to 3400 A, with the increase being appreciable for doses of more than 108 rad. The irradiation of film in a vacuum does not change the absorp- tion spectrum. The participation of oxygen in polymer damage from y radiation is confirmed by experiments on the etching of ion track channels. It was established that the etching rate along the diameter of a track channel of a xenon ion which entered the film at an angle of 90? was 1.3-1.4 times as large when irradiated with y rays in air as when irradiated in a vacuum. Figure 1 shows microphotographs of tracks of xenon and argon ions which entered the film at an angle of 30? with the surface. It is clear that irradiation with y rays is effective only in the presence of oxygen, and therefore the selectivity of the etching of ion tracks was studied for irradiation in air. The results of the study of the etching rate along a track Vtr, the etching rate of unirradiated film Vun, and the selectivity of the etching process Vtr/Vun as functions of the y dose are shown in Fig. 2. The electro- lytic method [4] was used to determine the etching rate along a track by the time to etch through an ion track channel. It was established that the etching rate of an unirradiated film increases for doses of more than 108 rad, which is in good agreement with the spectral data. The etching rate of a polymer track is appreciably increased even for a dose of 5 ? 105 rad, and therefore the selectivity of the process also increases. This in- dicates that a polymer damaged by ions is more sensitive to damage by y rays. It is interesting to note that the increase in the etching rate of an ion track in the polymer stops at a definite dose which depends on the ion type and energy. This can probably be accounted for by the extent of the polymer damage in the region of the track. The maximum etching rate and the selectivity of the process occur at a y dose of the order of 5 ? 106 rad for xenon ions, and at 4 -107 rad for argon ions. The energy of the xenon ions was 0.75, and that of the argon ions 5.6 MeV/nucleon. Our investigation showed that the effect of y radiation on increasing the etching rate of Lavsan tracks of argon ions with energies of 1.5 and 5.6 MeV/nucleon was greater for the higher energy ions. This is prob- ably related to the energy distribution of secondary delta electrons which are produced in the passage of ions through Lavsan, and in some way interact with it. The region of the polymer through which these electrons passed undergoes additional damage from y radiation, and the etching rate is greater than in a control sample. Translated from Atomnaya Energiya, Vol. 47, No. 4, pp. 261-262, October, 1979. Original article sub- mitted May 29, 1978; revision submitted June 18, 1979. 0038-531X/79/4704-0839$07.50 ?1980 Plenum Publishing Corporation 839 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 i?o ci 11.g. 1. Microphotographs of xenon and argon tracks in Lavsan films exposed to a y dose of 6.7 ? 107 rad a) in air; b) in vacuum; c) in control films. Films were etched in a 20% solution of NaOH at 20?C for 24 h 1000). 6 a 10 7 Dose, rad 108 200 100Z.L. ? >." 0 log 60 - 40 - 20 600 400 c 200 t. 0 10 107 10 109 Dose, rad Fig. 2 Dose, rad Fig. 3 Fig. 2. Rate and selectivity of the etching of tracks of a) argon and b) xenon ions in a 20% alkali solution as functions of the y dose at a) 50?C; b) 30?C: ?) experiment. Fig. 3. Etching rate of argon (I) and xenon (0) ion track channels in a 20% alkali solution at 50?C as a function of y dose. 840 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Since the selectivity of the etching process affects the shape and size of a track channel, it is interest- ing to trace the variation of a channel diameters with y dose for etching prolonged until breakthrough occurs. The channel diameters were measured by the "bubble" method [4], and the shape was observed with an optical microscope. Curves were obtained for the dependence of the etching rate of track Channels along a diameter VD on the y dose in air (Fig. 3). The sharp increase in the etching rate for doses above 108 rad for both kinds of ions is due to the damage of the material. The variation of the selectivity of the etching process with dose is most noticeable for argon ion tracks (Fig. 2a), and 18 reflected in the behavior of the curve for the etching rate of channels (cf. Fig. 3). The shape of the ion tracks after prolonged etching of the film can be seen in Fig. 1. The increase in etching rate resulting from y radiation is larger for argon than for xenon ions. In this experiment the argon ions had an energy of 7.6 and the xenon ions 0.75 MeV/nucleon. The results presented show that exposure to a certain y dose in air increases the etching rate of the polymer along an ion track and the selectivity of the process. This is related to the difference in sensitivity of the polymer to the action of 'y radiation before and after ionization damage in the region of an ion track. The decrease in selectivity for doses of more than 108 rad is explained by the sharp increase in the etching rate of polymer which has not been subjected to ion bombardment. Irradiation in a vacuum does not affect the etching rate of the polymer or the selectivity of the process, and therefore to increase the etching rate of an ion track in the polymer y radiation should be used only in the presence of oxygen. The authors thank G. N. Flerov for constant attention to the work and for valuable advice, Yu. S. Zam- yatnin for helpful discussions, V. A. Shchegolov and G. N. Akap'ev for performing the ion bombardment, and L. I. Samoilovaya, V. A. Shirkovaya, and P. Yu. Anel' for help with the work. LITERATURE CITED 1. R. Fleischer, P. Price, and R. Walker, Nuclear Tracks in Solids, Univ. of Cal: Press, Berkeley, Los Angeles, London (1975). 2. G. N. Akap'ev et al., Commun. JINR B-1-14-8214, Dubna (1974). - 3. W. Crawford et al., Nature, 220, 1313 (1968). 4. 0. N. Grigorov, Z. P. Koz'mina, and A. V. Markovich, Electrokinetic Properties of Capillary Systems [in Russian], Izd. Akad. Nauk SSSR, Moscow (1965), p. 30. USE OF CALIFORNIUM NEUTRON SOURCES TO DETERMINE BASIC ELEMENT-SALT COMPOSITION OF SEAWATER UNDER NATURAL CONDITIONS E. M. Filippov UDC 551.464.621.039.8 Californium sources have a yield of up to 1010 neutrons/sec. They can be employed to study changes in the element-salt composition of seawater under natural conditions [1-3]. We shall consider the application, for this purpose, of the neutron y--ray method (NGM) based on the (n, y) reaction and the neutron activation method (NA). In the case of the NGM for a point source and a detector separated by a distance /the equation for the counting rate is QesiM N ? 8n. V L2) B (L., L)-= QoB (Ls, L)=-- Qo IB(L)B(L)i. EI? (1) Here Q is the neutron yield from the source; e, detector efficiency; s, area of the detector; i, number of quanta formed during the capture of neutrons by chlorine; E and Es, macroscopic cross sections for the (n, y) re- action and neutron absorption in water, respectively; Ls and L, respectively, neutron moderation and diffusion lengths in seawater, and 1-1-1La ] _el/La Ei t_i(T-E-L;1)] , je-I/L8 [Ei / (t_L;N+ _-77?r431 B --r? (2) Translated from Atomnaya Energiya, Vol. 47, No. 4, pp. 263-264, October, 1979. Original article sub- mitted July 17, 1978; revision submitted April 2, 1979. 0038-531X/79/4704-0841$07.50 ?1980 Plenum Publishing Corporation 841 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 TABLE 1. Values of Functions B(Ls, L) at Various Salinities'of Seawater /, cm E , MeV Y Salt content in water, Otter 0 17,5 35 I 0 17,5 35 Point source and detector Point source and detector of finite size 10 ' 0,5 0,2233 0,2440 0,2535 0,07440 0,08284 0,08706 . 3,0 0,3232 0,3537 0,3696 0,1397 0,1548 0,1630 6,1 0,3535 0,3871 0,4051 0,1608 0,1781 0,1874 30 0,5 0,007135 0,007361 0,007309 0,005035 0,005231 0,005182 3,0 0,02199 0,02314 0,02351 0,01819 0,01916 0,01944 6,1 0,02922 0,03093 0,03162 0,02456 0,02601 0,02656 50 0,5 0,0003350 0,0003434 0,0003319 0,0002869 0,0002923 0,0002811 3,0 0,003164 0,003317 0,003332 0,002730 0,002842 0,002842 6,1 0,005433 0,005749 0,005837 0,004639 0,004874 0,004927 where T is the linear attenuation coefficient for rays. The functton B(L) has much the same form when Ls is replaced by L. If the detector and source are enclosed in casings of finite sizes with radii ri and r2 and distances hi and h2 from their centers to the ends of the casings aligned on one axis, then Eq. (1) can be recast as N = Q0 [B (L8)? AB (L8)- B (L)- (L)1= Q0B (L8, L). (3) Here the functions AB(Ls) and AB(L) take account of the interaction in external space, between the ends of the source and detector casings, and B(Ls) and B(L) take account of the interaction in the inner space. Let us calculate these functions. If the radii of the source and detector casings are equal, r1=r2=r0, then B (L. - cul/L8 Ei (1+1;1) Oh+ = u-I-Ody; (4) -a al AB (LB)= f (Ls, dy- (L8, 1+ y) dy, . (5) a2 ?2 where u = 171 + (2r0/1)2/(1 - y9, al = 1 - 2h1n, and as -1+ 2h2/1, f (Ls, 1 + is the same as f (Ls, u +y) when u is replaced by unity. In the case r4 r2, the integrals under consideration become B (L8)= f (Ls, y) dy f (L ? 141+ y)dy; (6) 0 al a0 al AB (L8)= f (Ls, ui+ Y)(1Y + f (Ls, 1+y) dy I (Ls, 1/2? y) dy+ f (L8, 1+y) dy. (7) 0 0 The functions ui and u2 are the same as u when r0 is replaced by ri and r, respectively. Californium sources, as is known, are extremely small in size and, therefore, in our calculations can be assumed to be point sources. In this case ri =hi =0 and, therefore, u1=a1=1. Equations (6) and (7) simplify here to --1 B(L3)-= - S f(4, 1+ y) dy+ S f (L8, u2+y) dy; 0 a2 a2 (L8)== - (Ls, u2+ 04+ C (Ls, 1+ y) dy. (8) (9) All the integrals must be calculated numerically. In all cases the functions B(L) and AB(L) are analogous to the functions B(Ls) and AB(Ls) when Ls is replaced by L. Calculations of these functions for a point source and a detector of Eq. (1) and for a point source and a "Limon" Nal(Tl) detector of standard size (15x 10 cm, d=2, r2=15 cm, h2=5 cm) by Eqs. (8) and (9) are given in Table 1. A salinity of 17.5 g/liter corresponds to the waters of the Black Sea and 35 g/liter, to oceanwater. It is seen from Table 1 that with an in-crease in 1 the values of the functions B(Ls, L) decrease sharply where- as with an increase in the 'y-ray energy and the salinity of the water they increase slightly. Taking the detector 842 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 TABLE 2. Expected Errors of Determination of Chemical Elements of Salt Composition of Black Seawater Element C, g /liter T E. MeV i , c - 6C, % Sodium 5,25 15 h 2,76 1 7,42-10-8 0,805 1,38 1 Bromine 0,0325 17,55 min 0,62 0,13 1,07.10-8 8 Magnes. 0,675 10 ? 1,013 0,3 4,8.10-8 23 Calcium 0,2 8,75 " 4,68 0,03 5,2.10-8 23,5 4,05 0,08 3,1 0,89 geometry into account results a decrease in the values of the functions B(Ls, L). The most pronounced change in the geometry of measurements turns out to occur for small values of 1. This is due to the fact that the gap between the casings of the source and the detector when their concrete dimensions are introduced is small in comparison with 1. With NGM, in the case of neutron capture by chlorine y rays with an energy of 6.11 MeV (i =0.1578) are formed with the highest probability. Therefore, all NGM calculations were carried out for that radiation. In interaction with the material of the detector this radiation splits because one of two photons with an energy of 6.51 MeV is carried off. As a result, there is a triad of -y-rays quanta with energies of 6.11, 5.60, and 5.09 MeV. In measurements at the optimal distance of 20 cm for 1 sec we recorded 1403, 2022, and 2265 counts/ sec, respectively, in these photopeaks (with Q=108 neutrons/sec). From the total counting rate the chlorine content in Black Seawater (9.5 g/liter) is determined with a relative error of (5C =1.325% and with a measuring time of 2 sec, with a relative error of 0.94%. The equation for the counting rate of y rays from radionuclides formed during NA will be of a form anal- ogous to Eqs. (1) and (3) with Q0 replaced by Qi = QesiZ f(:)/4, (L: ? L2). Here, 1(t) = iTe?[1 ? exp 0693 ti)] 0.693 0.6293 tas x lexp( ? ) ?exp(--- 1 a time factor in which h, tp, and tare, respectively, the irradiation time, the pause, and the decay time of the induced activity after the irradiation of the medium under study has ended, and T is the half-life. The chemical elements which are best activated by the NA technique are those given in Table 2 for a source with a yield of 108 neutrons/sec. The functions B(Ls, L) for y rays from the radionuclides formed can be easily estimated from the data of Table 1. In calculations of the counting rate by the NA technique, we have tp =0, tt --t= 30 min. When the activity of the source is increased by an order of magnitude there errors decrease by roughly a factor of three. In these analyses potassium can be determined from the natural radio- activity of 40K (Ey =1.46 MeV). With a measuring time of 1 h the potassium content in Black Seawater (0.19 g//) is determined with a relative error of 1.74% (data of the experiment). LITERATURE CITED 1. E. M. Filippov, Marine Hydrophysical Research [in Russian], No. 3 (78), Sevastopol' (1977), p. 138. 2. E. M. Filippov, Nuclear Prospecting for Useful Minerals [in Russian], Naukova Dumka, Kiev (1978). 3. E. M. Illippov and I. A. Lamanova, Marine Hydrophysical Research fin Russian], No. 1 (80), Sevastopol' (1978), p. 98. 843 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 Declassified and Approved For Release 2013/02/15: CIA-RDP10-02196R000800020004-1 EFFICIENCY OF NUCLEAR-FUEL UTILIZATION BY MOLTEN-SALT CONVERTER REACTORS V. M. Novikov and V. L. Blinkin UDC 621.039.542.4 The molten-salt reactor (MSR) is usually considered as one possible system capable of ensuring ex- panded production of fissionable materials in the uranium?thorium fuel cycle [1, 2] if continuous extraction of fission products is organized right at the reactor. However, in the first stage of development such reactors can apparently operate without continuous fuel reprocessing [2]; it therefore makes sense to estimate the effi- ciency of a MSR operating without continuous extraction of fission products. In this case the reactor operates in the breeder mode (with a conversion ratio of less than one) and should be continuously supplied with make- up fissionable fuel. Not only a uranium?thorium fuel cycle but also a uranium?plutonium cycle can be rea- lized in a molten salt breeder reactor. The maximum possible concentration of fission products in the fuel salt is limited by their solubility which reaches 5% at the operating temperature (700?C). Such a concentration in a reactor of the MSBR-1000 [1] type in the absence of fuel reprocessing is attained after 12 years of operation. The molten-salt breeder reactor can, therefore, operate with one charge of salt-carrier for 10-12 years with a continuous supply of make-up enriched uranium to compensate for the burn-up and poisoning of the reactor with fission products. At the end of a run the fuel salt is replaced by fresh salt (open cycle) and the fissionable material contained in the spent salt can be extracted from it by the fluorination method, whose technological feasibility was demon- strated on the 8-MW experimental reactor MSRE [4], and returned to the fuel cycle (closed cycle). The fuel component of the cost of electrical energy generated by an MSR will be several times lower than for present- day light-water reactors (LWR) [5]. This estimate, however, is associated with the uncertainty of the prices of the fuel itself as well as other components of the fuel composition. At the present time, therefore, it is more objective to estimate the efficiency of utilization of natural resources of nuclear fuel; quantitatively, this can be characterized by the utilization factor for natural fuel, defined as (1) where Q(t) is the quantity of electrical energy produced by the energy system in the time t and G(t) is the inte- grated consumption of natural fuel (natural uranium or thorium) during that time. With the continuous growth of nuclear power the fuel consumption G(t) can be written as [6] I ti G (()=-- W (0) y (I') + dti Y (12 12) dW (t2) dt2 dt2, 0 0 (2) where W(t) is the total nuclear energy at the time t and y(t) is the rate of natural-fuel consumption per unit nuclear power. If the duration Ti of the reactor run is taken to be a fraction of the reactor lifetime Tc, i.e., Tc =nri, where n is an integer, then the function y(t) is of the form y (t)=__ Y,45 (0+ Yi (0?y26 (I ? T1), 0