The use of empirical constants in shielding design

The article contains a generalization of the results of experimental and theoretical investigations relating to the determination and use of removal cross sections. It also considers the questions of the possibility of extending the region of applicability of empirical constants for the design of various kinds of neutrons shielding. A table gives the values of empirical constants for calculating the penetration of fast neutrons.The authors are also grateful to I. I. Bondarenko, V. I. Kukhtevich, Yu. A. Kazanskii, A. A. Abagyan, D. V. Pankratov, and A. P. Suvorov for their valuable advice in preparing the material for publication.     

Radiation Service Life of the Vessel Metal in Operating VVER Reactors

The current status of the prediction of radiation embrittlement of the vessel material in first- and second-generation VVER reactors is analyzed. The radiation service life of the vessel of each type of reactor is determined by factors due to the special features of the operating regime of the reactor and the chemical composition of the vessel metal. A method of monitoring the state of the material of first-generation reactor vessels is examined. The method is based on extracting and studying samples of a metal from the inner surface of the sample. The main problems of monitoring the state of the metal in VVER-440/213 and VVER-1000 vessels are analyzed. It is indicated that adjustments must be made in the normative relations which are currently used for predicting radiation embrittlement of vessel material. The most important questions concerning reactor dosimetry for VVER vessel material are illuminated.__________Translated from Atomnaya Energiya, Vol. 98, No. 6, pp. 460–472, June 2005.     

Adaptation hypothesis on the biological effectiveness of ionizing radiation

Leningrad Scientific-Research Institute of Radiation Hygiene. Institute of History of Natural Sciences and Technology of the Russian Academy of Sciences. Institute of Limnology of the Russian Academy of Sciences. Translated from Atomnaya Énergiya, Vol. 73, No. 1, pp. 27–32, July, 1992.     

Techniques for the preparation and identification of transplutonium elements

A short review of the discovery of transuranium elements is given and methods of preparing and identifying them are described. The results of a thorough experimental check of the work of a group of scientists from the USA, Britain, and Sweden on the preparation of element 102 are given.A radical new method used for preparing isotopes of element 102 is described in detail. Data on the properties of two isotopes of this element are given. The half-life of an isotope of element 102 with a mass number of 254 is 3 sec and the -particle energy is 8. 3 Mev. In 30% of the cases of decomposition, this isotope undergoes spontaneous fission. According to preliminary data, the isotope of element 102 with a mass number of 253 has an -particle energy of 8. 8 Mev.The agreement of the results of this work with the data obtained by G. N. Flerov et al. is noted. In conclusion, possible ways of preparing and identifying elements with an atomic number Z above 102 are examined briefly.Report read at the Eighth Mendeleev Congress in Moscow (March, 1959).     

Influence of eccentric valves on the vibration of fluid conveying pipes

The dynamic stability of motion of fluid conveying pipes has been the subject of numerous studies. Theoretical interest was stimulated by the non-conservativeness of these systems. Design requirements for pipelines and nuclear related systems provided the additional impetus.Recently, the assessment of the probable influence that large, rigid valves frequently encountered on piping systems might have on the behavior of the overall system was required. In spite of the above mentioned wealth of literature, a great paucity of information was found on the influence of lumped masses. Consideration of rotatory inertia is apparently non-available. The motivation and contents of the present study stem from these facts.A variational formulation is followed by a Galerkin approximation that is applied to simply supported and cantilever pipes. Lumped translational and rotatory inertia are introduced. The results are reported for values of dimensionless parameters selected in a representative manner.Substantial modifications on the magnitudes of the frequencies are shown. The influence of the eccentricity is found of greater importance than that of the mass for constant eccentricity factor. The character of the equilibrium configurations associated with vanishing frequencies is a function highly dependent on the mass and eccentricity of the valve.The need for ensuing research on coupled out-of-plane bending and twisting of the pipe system is also established.     

On the change in the color and transparency of glasses when bombarded by gamma rays from a Co60 source and in a nuclear reactor

Glasses of various types are widely used in radiation shielding. The problems involved in the effect of different types of radiation on glasses and the choice of glass with greatest radiation stability become important in this area. The present article deals with these questions.Results of experimental investigations where glasses of different types were subjected to bombardment from a Co⁶⁰ source and to bombardment in a nuclear reactor are discussed. Glasses of different composition, products of several different glassworks in the USSR, were tested. Techniques for enhancing the radiation stability of the glasses are recommended in this article. Those characteristics of glasses which provide a fairly complete picture of the radiation response of the materials, e. g., index of stability, index of saturation, minimum transparency, coefficient of rate of darkening, are introduced.In conclusion, I would like to express my acknowledgment to G. Ya. Vasil'ev and Yu, Ya. Zhelazova for their kind assistance in performing the experimental research discussed herein.     

The concept of "safety"

Conclusions The systematic view of safety presented here is of a general nature, in contrast to the majority of other studies (for example [1–3]). Many authors define safety as a state of protectedness. However, if one understands protectedness in the sense adopted in the present paper, the concept of safety has a wider significance. In [3] safety is also considered from a systems point of view and three attitudes in society are distinguished characterizing the defined position of some subject-agent in the situation of guaranteeing safety. However, the whole course of the discussions and the concept adopted for safety differ considerably from those given here. Special attention has been devoted in the present paper to the relative nature of safety and the importance has been mentioned of distinguishing and comprehensively studying the different aspects of safety when adopting solutions. By virtue of the systems approach and the relative nature of safety, its definition as properties of an object is imprecise, although the concept of a safety object can be used if one takes account of its relative nature. The safety threshold defines the standard of safety, Although there is no scale of safety in terms of this concept, standards of safety can be compared in different fields or different countries. The lowest level of acceptable risk, i.e., the most rigorous establishment of the safety threshold, provides a basis for speaking of a higher standard of safety. Kurchatov Institute, Russian Scientific Center. Translated from Atomnaya énergiya, Vol. 80, No. 6, pp. 415–420, June, 1996.     

Perturbation theory formulas for the effect of the dimensions on the critical mass in a fast reactor

This paper deals with a method for calculating the critical mass of a reactor provided with a sufficiently thick reflector as a function of the composition of the core and its dimensions.The working formula is obtained by an application of the theory of similarity to the usual first-approximation scheme of perturbation theory. For the calculation of the coefficients of the formula it is necessary to have the spatial and energy spectra of the neutron fluxes and values calculated numerically for some fixed volume of the reactor with a sufficiently thick reflector. By means of the coefficients so obtained for the formula it is possible to predict the critical mass over a wide range of variation of the dimensions of the core (over a change by about a factor two).If the size of the core goes beyond the limits of the interval thus accessible, one has to calculate the coefficients for a new range of the dimensions, and this requires a new numerical computation of the spectra.In this paper we give a formula containing coefficients calculated for a certain typical spectrum of a fast reactor for a number of isotopes contained in the core. The formula is checked by a nine-group calculation for volumes of the core ranging from 200 to 1000 cubic decimeters. The constants for the nine-group calculation were obtained from Soviet and foreign material published up to 1955.In conclusion the writer thanks Active Member of the Academy of Sciences of the Ukrainian SSR A.I. Leipunskii, G.I. Marchuk, and L.N. Usachev for a discussion of the work.     

重离子和γ辐照硼硅酸盐玻璃的辐照效应对比

为研究玻璃固化体在不同辐照方式下的宏观和微观结果及其对应关系,使用重离子和γ辐照硼硅酸盐玻璃,分别测量了辐照后硼硅酸盐玻璃的硬度和模量变化。发现在γ辐照条件下,直到吸收剂量达到6×10⁶ Gy,硼硅酸盐玻璃的宏观性质（硬度和模量）均未发生明显改变。在Xe离子辐照条件下,当辐照剂量达到0.1 dpa时,硬度和模量减少达饱和值。此外,测量了γ辐照后的硼硅酸盐玻璃的吸收光谱,得到了辐照后硼硅酸盐玻璃带隙随吸收剂量的变化规律,讨论了辐照产生的微观缺陷来源和产生机理。发现重离子辐照产生的硬度和模量的下降主要来源于玻璃网络结构的断裂,而重离子的核能量沉积是造成网络体结构断裂的主要原因。结合γ辐照样品的吸收光谱结果,通过对比γ射线和重离子辐照后的样品硬度和模量变化不同趋势可发现：γ辐照会在硼硅酸盐玻璃中产生微观缺陷（非桥氧空位色心等）,这些缺陷主要来源于网络体末端与钠相连的键的断裂。而网络体末端的断裂不影响硼硅酸盐玻璃的网络体结构,所以γ辐照产生的缺陷不会引起硼硅酸盐玻璃的硬度和模量变化。     

Radiation characteristics of reactor structures after the final shutdown of a nuclear power plant with RBMK reactors

A method for obtaining computational estimates of the radiation characteristics of irradiated structures in RBMK reactors is described. It is based on the MCNP computer program for calculating the spatial distribution of the neutron flux density inside the shaft. The nuclear transmutation occuring in the materials of the structures under irradiation in the reactor and during the subsequent holding period is simulated by the CHAIN program for calculating the isotopic composition and the radiation characteristics on the basis of the MCNP fluxes. Some results of a calculation of the radiation characteristics of the structures in the reactors in the No. 2 and No. 3 units of the Leningrad and No. 1 unit of the Chernobyl nuclear power plants are presented. Estimates of the total activity of the reactors structures and the dose rate near individual components are presented. The distribution of the mass of the structures over the degree of radioactivity is obtained as a fucntion of the holding time of a unit.Translated from Atomnaya Énergiya, Vol. 97, No. 6, pp. 451–457, December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

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

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

金的找矿标志——黄铁矿的穆斯堡尔谱

火成岩中浸染状及网脉状金银矿床中,自然金常产在黄铁矿中。破碎带经历多次构造活动,经应力作用改造而成,从而也引起多次热液活动的发生。从玲珑和新城两矿区大量的岩矿鉴定资料来看,其中低温脉旁交代黄铁绢英岩化作用与金的矿化有关。按热液活动的产物,不同的共生组合分为三个阶段:第Ⅰ成矿阶段。银金矿——绢云母——石英菱铁矿——黄铁矿阶段。第Ⅱ成矿阶段。银金矿——绢云母——石英——多金属硫化物阶段。第Ⅲ成矿阶段。     

Solidification of low-level-radioactive resins in ASC-zeolite blends

Solidification of low-level-radioactive (LLR) resins was studied in ASC (a kind of new cement)-zeolite blends. The effect of addition of zeolite on the strength of the cementation matrix was investigated. A superior combination was obtained as ASC 35 wt.%, zeolite 7 wt.% to mix 42 wt.% of resins with 16 wt.% of water, the moisture content of the resins was about 50%. The simulated leaching tests showed that inclusion of zeolite in ASC reduced the leaching rates of radionuclides significantly. From tests of 200L, the center temperature curve was measured, and no early thermal cracks were found.     

Determination of the probability of spontaneous fracture of metal from the acoustic emission spectrum at the prefracture stage

The Weibull distribution is used to calculate the probability of failure of any type of system. In the case of the fracture of metal, the squared critical stress is taken as the random variable and the fractal dimension as the form parameter. Fluctuations of the critical stress intensity at the prefracture stage are accompanied by an acoustic response (acoustic emission). It is concluded that information about the acoustic emission intensity (amplitude criterion) is not enough to calculate the probability of spontaneous failure. It is also necessary to take account of the temperature and fractal dimension of the prefracture region. It is proved that the fractal dimension can be determined from the acoustic emission spectrum. The results of a determination of the instantaneous probability of spontaneous failure of samples of corrosion-resistance steel on the basis of acoustic emission spectroscopy are presented. __________ Translated from Atomnaya énergiya, Vol. 102, No. 6, pp. 351–358, June, 2007.     

Measurement of neutron spectra in the thermal column of the reactor of a power station

Knowledge of neutron spectra In nuclear reactors allows comparison of various theories of the slowing down of neutrons with experiment, and also allows carrying out reactor calculations which are based on actual neutron distributions therein. In this paper is described a neutron intensity monochtomator Intended for the measurement of neutron spectra in the energy interval 0 to 0.5 ev.Results are given for measurements for neutron spectra in the thermal column of the reactor of an atomic power station. Discontinuities in the neutron flux were discovered at neutron velocities of 600, 1000 and 1650 m/sec; an analysis is given of the causes of discontinuities of the neutron flux; an evaluation is made of the inelastic scattering cross section for neutrons in graphite. By the method of least squares, the temperature of the neutron gas was found, being equal to 354 ° K at a graphite temperature of 304 ° K.In conclusion we consider it our duty to express gratitude to A. K. Krasin and B. G. Dubovskii for interest and help in the work and F. L. shapiro for valuable interpretation of previous results.     

不可压缩流中非对称板状结构模态局部化分析的摄动法

本文研究了一个两跨板状简单模型在不可压缩流中振动时的固有动特特。应用假设模态法建立系统的运动微分方程，应用摄动法看考虑了结构的长非对称及扭转刚度非对称对系统模态局部化程度的影响。结果表明，二阶摄动理论能很好地用于计算该系统的动态特性，水的耦合作用对上、下板模态局部化现象的影响有差异。长度非对称参数是导致结构模态产生局部化现象的主要原因，扭簧刚度扰动也对结构模态局部化现象有较大影响。     

Nonlinear theory for slow waves in a plasma

The propagation of electromagnetic waves is considered in the nonlinear approximation for the case of a narrow plasma waveguide. The dependence of phase velocity on amplitude is determined. The problem of frequency multiplication is examined. The amplitude of the second harmonic is determined. Because of the nonlinear effects a new possibility arises for changing the phase velocity of a wave by changing the amplitude; the possibility also arises of new methods of providing radial and phase stability in accelerators and certain improvements in methods of amplifying and generating microwaves.Reported to the Scientific Council of the Physico-Technical Institute of the Academy of Sciences, Ukrainian S.S.R. in 1956.In conclusion I wish to express my gratitude to K. D. Sinel'nikov and A. I. Akhiezer for a discussion of the results of this work.     

Databank for the current-voltage characteristics of thermionic converters

Investigations of thermionic converters, supporting design investigations and developments in space nuclear power systems, are being conducted in the Laboratory of Studies of Fundamental Problems of Conversion of Various Forms of Energy at the State Science Center of the Russian Federation—Physics and Power-Engineering Institute. As a result, a great deal of experimental data has been accumulated in the form of the current-voltage characteristics of arc operating regimes with different electrode materials. The databank stores the experimental data in electronic form. At present it contains the results of 17 experiments. For data handling convernience, a program for viewing the entire digital information has been developed. The results of a search can be printed out. The data control apparatus makes it possible to select the data required by the user. A current version of the databank is discussed as an example. 6 figures. 1 table, 13 references. State Science Center of the Russian Federation—A. I. Leipunskii Physics and Power-Engineering Institute. Translated from Atomnaya énergiya, Vol. 89, No. 1, pp. 71–74, July, 2000.