Natural uranium is considered the main resource of nuclear power based on thermal neutrons. It is a rather common element, though its concentration in natural substances is usually very low. The cost of production of uranium is an important factor for development of nuclear energy. Depending on the production cost of 1 kg of uranium, uranium ores are classified into four categories of cost. Deposits of uranium ores are distributed unevenly around the globe. Currently, 28 countries mine uranium ore from their bowels, yet only 19 countries produce uranium fuel. In the world there is a significant discrepancy between the countries leading in terms of the world's reserves of uranium and its main consumers. In countries like Australia, Kazakhstan and South Africa, nuclear power is underdeveloped, and uranium consumption is very low or non-existent. These countries have a large uranium resource base and are today global exporters of uranium ores. At the same time, countries like the US, China, Japan, Britain, France, or Germany, by contrast, have a well-developed nuclear industry and a lack of sufficient uranium ore deposits in their territory. They serve, as a rule, as major importers of uranium / uranium ore. The article considers the world's reserves of uranium in different price categories, the global reserves by countries, and unconventional uranium resources; provides an overview of reserves in Russia, the demand for uranium, global production volumes by countries, mining companies, uranium production output in Russia, with general conclusions made on development of the resource base of nuclear power.

There are considered the key milestones in the development of the Russian nuclear power: the fi rst studies of nuclear physics (the 1920s – 1930s); implementation of the «atomic project» (the 1940s); large-scale development of civil nuclear energy (the 1950s – 1980s); a crisis and restoration of nuclear industry (1990 – 2007); active development on the global nuclear energy market (2007 – present). Analysis is provided of the current state and development prospects in all the key segments of the nuclear industry in Russia: uranium mining, uranium conversion, uranium enrichment, nuclear fuel fabrication, construction of nuclear power plants (NPPs), nuclear power engineering, operation of NPPs and power production, maintenance of NPP power units, decommissioning of NPPs, handling radioactive waste and spent nuclear fuel. Russia is identifi ed as one of the global leaders in all these segments of the world nuclear market (having, among other things, the world’s largest portfolio of NPP orders and the largest uranium enrichment capacities). The export potential for each of the nuclear industry segments under consideration is identifi ed and assessed. It is shown that the segments of NPP construction and manufacturing of nuclear power equipment production are of the largest export potential for Russia. At an early stage of the nuclear fuel cycle, the segment of enriched uranium product and nuclear fuel fabrication has the greatest prospects for growth in export supplies due to the growing number of NPP units of Russian design in the world and Russia’s entry to the market of fuel fabrication for reactors of foreign design.

A significant potential for reduction of energy consumption determines the importance of energy conservation and energy efficiency as key areas for economic growth in Russia and enhancing its competitiveness, and emphasizes the need to explore and improve the process of energy management and raising energy efficiency at the corporate level. The main factors that hinder implementation of systematic management of energy conservation and improvement of energy efficiency based on international standard ISO 50001:2011 (GOST R ISO 50001-2012) is the poor knowledge of the mechanisms of self-assessment of the current state in the field of energy saving and increasing energy efficiency, as well as inadequacy of methodological base for substantiation of economic efficiency of measures on improving energy saving and energy efficiency, including the effectiveness of implementation of the energy management system (EMS) and other organizational events. It is essential to analyze the existing practice of Russian organizations in implementation of EMS and to develop approaches to evaluation of energy saving activities of organizations. Identifying best practices for raising energy efficiency is necessary for implementation of the state policy in the field of energy saving and energy efficiency improvement and encouraging companies to reduce energy intensity of production. To encourage companies to reduce energy intensity of production, identifying the best practices, the authors propose a methodological approach to assessing the efficiency of organizations. The methodological approach presented in the paper, in general, enables to carry out monitoring and comparative analysis of efficiency of management of energy conservation and improvement of energy efficiency by industry sectors, and for the Russian Federation, as a whole. The tools developed can be used by organizations of fuel and energy complex, industrial enterprises, organizations that are major consumers of Russia’s fuel and energy resources, for substantiation of making decisions on implementation and development of EMS, and make it possible for companies to evaluate the effectiveness of implementation of the EMS.

As a consequence of the recent deregulation in the electrical power production industry in Europe and worldwide, there has been a shift in the traditional approach to ownership of power-generating assets, in particular, during the period of their operation. The current market conditions have seriously challenged gas turbine plant operators (GTO) to reduce their operating costs. The paper analyzes the current global situation with organization of service of power-generating medium to high capacity gas turbine engines (GTE). The patterns are presented of management of the lifecycle of these sophisticated and capital-intensive items depending on the level of their development by generating companies and emergence of necessary operational competencies. Analysis of the record of operation of service companies and operators of thermal power plants in the world’s different countries and regions proves that competition is possible in the field of servicing high-capacity powergenerating GTE. The next stage of strengthening of the market is consolidation of GTOs with the purpose of optimization of operating costs. The record of the European Union in creating collective mechanisms to cost optimization of gas turbines maintenance is described. The paper recommends a scheme of a similar mechanism in Russia (including the new Association of Operators for Service Organization (AOSO)) taking into account peculiarities of the state management of power engineering and electrical power generation, as well as the existing sectoral and cross-sectoral professional associations opportunities. The basic objectives of the AOSO are presented and discussed. The paper also reviews organizational forms of AOSO, which are currently the most efficient in the Russian energy sector. A conclusion is drawn that, at present, this is the Ministry of Industry and Trade that should play the key role in development of collective mechanisms for optimization of GTE operation expenses.

In this paper we deal with the problem related to effective assessment of reliability of electric power systems, particularly, the efficiency of pseudorandom number generators while using the Monte Carlo method for generation of random states of electric power systems. We consider the efficiency of four pseudorandom number generators: linear congruential generator, lagged Fibonacci generator, Mersenne Twister and Sobol sequence. The Kolmogorov-Smirnov test for analysis of randomness of sequences was used to analyze the above pseudorandom generators. Based on this analysis, it has been determined that the most random sequence may be obtained while using the Sobol sequences generator. Next, visual analysis of these pseudorandom number sequences was conducted. It showed that 2d points gained from the Sobol sequence filled the surface more evenly than other generators, where as the linear congruential generator and the lagged Fibonacci generator would form voids. In the final part of the research, the analyzed pseudo random generators were used in a model for reliability assessment using the Monte Carlo method. We modeled a three-node electric power system test scheme. As a result, the linear congruential generator and the lagged Fibonacci generator did not stabilize even after ten thousand random states of the system. These results correlate with the Kolmogorov-Smirnov test and show that these generators are barely random and unsuitable for reliability assessment using the Monte Carlo method. The Mersenne Twister and the Sobol sequence results were much better. The expected value of power shortage stabilized by the 4000th rando state with the Sobol sequence. In conclusion, we can say that the Sobol sequence is the most suitable pseudorandom generator for reliability assessment using the Monte-Carlo method than the other generators considered above.

In this article we have studied the statistic materials for failures and malfunctions that aff ect the performance of heat power installations. This is a qualitative analysis and quantitative assessment of indicators of reliability of different turbine types. In the paper, there is presented a mathematical model of variation for output characteristics of a turbine depending on the number of failures observed in the course of operation. The mathematical model is based on methods of mathematical statistics, the probability theory and methods of matrix calculus. The novelty of this model lies in the fact that it allows predicting variation of control parameters and the output characteristic in an explicit form. The parameters that can be assumed as such characteristics are: average load, heat generation and electric power generation, running time, amount of time spent on emergency repair, number of staff participating in repair, cost of repair, income from sales of thermal and electric energy, availability quotient, probability of no-failure operation, etc. Based on the statistical data obtained at operation of steam turbines, quality and quantitative assessments of reliability indicators has been presented. Specific measures are suggested for elimination of causes of failures of components of turbines and turbine equipment. These are the failures of turbine blades caused by exhaustion of service life and extreme fatigue of metal that are accounted for the largest number of cases of damage and failure of turbines. Statistics of failures of bearings are affected by both internal and external factors of technical and operational nature. Damage of bearings and parts of rotors most often leads to unscheduled shutdown and repair of the turbine. The most common failures are those of the main oil pump and oil pipelines. According to statistical data, it is possible to develop appropriate measures for improvement of output characteristics. This is a so-called a model of management of output characteristic. For the purpose of management of the output characteristic, a probabilistic model taking into account the operating influences in an explicit form has been offered. A specific example of variation of turbines' output characteristics over a long-term period of operation has been given.

Today, we no longer have to prove the need for numerical evaluation of reliability of in-plant power supply systems. There have been established generally accepted reliability indices in the form of frequency of various accidents and mathematical expectation of undersupply of electricity to consumers, or decrease of power generation by plants. Factors are revealed factors that must be considered at analysis of reliability of power supply systems: availability of repair of switching circuits and duration of repair of the main equipment and switching equipment, failures of switching devices and devices of relay protection and automatics, routine switching, seasonal variations in damage to overhead lines and outdoor equipment. Here, one should take into account a possible lack of reliable initial information about the reliability of elements at the consideration of a specific installation. The paper formulates models of the analytical method of calculation of reliability parameters of elements of power supply systems in the Matlab software. Reliability models are considered for power units, which involve restoration and prevention activities. Three states of a system are considered: operable state; emergency downtime and recovery, scheduled downtime for preventive maintenance or repair subject to intensities of emergency and planned outages, intensities, recovery and completion of scheduled maintenance and repair. It is shown that, at present, targeted screening and quantification of contributions to unreliability of power supply systems by failures of elements of the system, its states and modes, as well as effectiveness of various measures, allow to identify weak links of the power supply systems and to work out specific ways for improvement in the process of human-machine synthesis of the power supply system. This approach to design involves searching for new circuit solutions, and changes in the structure of the circuit and layout solutions of its equipment mitigation of weaknesses, elimination of excessive equipment, or, on the contrary, using more reliable equipment, as well as its modernization.

This article presents an analysis of limitations of the adjustment load range of a 325 MW combined cycle power unit (CCP-325) based on two GTE-110 gas turbines. It is noted that CCP-325 should have the minimum capacity of about 30% of the nominal capacity (with one GTE-110 disabled) to ensure reliable operation without time restrictions. The article describes the features of GTE-110 operation:
1) Operation with inlet guide vanes (IGV) of the compressor fully opened at the GTE-110 capacity below 65% of nominal capacity required by the manufacturer.
2) GTE-110 capacity changes abruptly in the 18-48 MW range.
The following factors were taken into account to determine the CCP-325 minimum allowable capacity:
1) The minimum allowable temperature of high-pressure inlet steam set by the manufacturer is 473°C (emergency shutdown at 440°C).
2) GTE-110 is operated with gas fed into the both areas of the combustion chamber.
3) GTE-110 operation at 65-100% of the GTE-110 capacity within the range of compressor IGV adjustment.
The article shows that the minimum allowable GTE-110 capacity is determined by the lowest allowable temperature of high-pressure inlet steam, that is 450°C, on condition that the gas feeding algorithm is adjusted. Based on this conclusion, calculations of the CCP-325 minimum capacity are performed. Results are presented as follows:
1) The CCP-325 adjustment load range is 69–100% with account to the GTE-110 manufacturer’s restriction.
2) Implementation of the recommendations provided in the article will allow reduction of the CCP-325 minimum capacity to 42% of the nominal capacity.
3) Partial disabling of CCP-325 equipment will allow reduction of CCP-325 minimum capacity to 34% of the nominal capacity for operating GTE-110 and to 20% if the suggested recommendations are implemented.
It is demonstrated that energy effi ciency of unloading CCP-325 is achieved with a capacity of at least 78 MW with incomplete set of equipment and 139 MW with complete set of equipment.

The results of studies are presented identifying structural causes resulting in malfunctions in operation of the thermal expansion system (TES) of steam turbines. A model is developed and used as a basis for analysis of interaction between the turbine cylinder, the bearing housing and the bed frame taking place as the cylinder is affected by shear forces and moments from connected pipelines. Possible options have been studied for the contact in a pair «longitudinal key — groove in the bearing housing». It is shown that the most unfavorable for TES is the «diagonal» type of contact. The results of the simulation show the effect of the ratio of values of the gaps in the TES keyed connection on the probability of «diagonal» contact and jamming of bearing housings on longitudinal keys. The technique is presented of building «a stability diagram» aimed at evaluation of resistance of the turbine cylinder TES to external impact. As an example, results are shown of stability studies for a high-pressure cylinder and a front bearing housing with dimensions corresponding to those of the T-175/210-130 turbine. It is proved that to ensure reliability when designing new or upgrading existing turbines one should take into account the effect of the ratio of clearance values in the elements of the thermal expansions system. The values of the selected clearances in joints of the TES elements must exclude the possibility of jamming of bearing housings on longitudinal keys. It is shown that an increase in the clearance in transversal key joints during the turbine operation increases the probability of jamming. It is proved that to ensure reliable TES operation, every major overhaul of the turbine must involve performing work on restoration of clearances in transversal key joints or using «swivel» keys, which are not exposed to variation of clearances changes under mutual angular displacements of the turbine cylinder feet and corresponding support surfaces of bearing housings.

Considered is the possibility of using a proportional type automatic excitation regulation implemented in the form of compounding devices with an electromagnetic voltage corrector changing excitation depending on the frequency and voltage at the generator terminals in particular power supply systems. It is demonstrated that the suggested solution is more efficient compared to automatic excitation regulators having no frequency control. Graphs are provided showing changes in consumption of active and reactive power by an equivalent load characteristic of industrial customers, depending on frequency, and depending on voltage. Analysis of the evaluation results shows that implementation of the proposed solution reduces the active power imbalance from 6.5% to 3.5% (with a 10% frequency decrease). Proportional type automatic excitation controls with frequency control may find application in in-house power supplies of companies with a continuous operation process, where high quality of power supply is achieved by using a second independent power supply generated on a standalone basis, with no connection to the power grid. As the record of operation of such enterprises shows, the effectiveness of such a solution is quite high due to minimization of damage from voltage dips that occur in the external power supply system due to damage and abnormal conditions in 110 and 220 kV networks. As recommendations, features are assessed of the proposed automatic excitation regulator with frequency control in an embodiment providing for generators of the companies’ own power supplies operating in parallel with the external power grid, as well as in cases of some disruptions of static stability.

The Education and Science Ministry of the RF provides financial support to a number of universities under the Federal Special Program «Research and development on top priority directions of elaborating the scientific-technological complex of Russia for 2014–2020». According to the above Program, the Ministry expects «identifying directions and developing technological solutions providing growth of thermodynamic and technical-economic efficiency for distributed and low power engineering facilities». In particular, under agreements made between the Ministry and the university engaged in R&D, articles are to published in the «Heat Power Engineering» journal, which will be considered as a kind of reports on R&D fulfilled. However, analysis of the already published articles-reports suggests a poor theoretical background of the authors in the fields of thermodynamics, turbomachines theory, and heat power engineering. Besides, the above analysis provides evidence that the studies presented are characterized by the absence of promising developments and tend to present previously known technical solutions whose thermodynamic efficiency has not been proved. Besides, the analysis performed suggests that some of the technological solutions suggested by the authors cannot be implemented. The analysed publications provide no results of determination of thermodynamic efficiency of the suggested expander and trigeneration systems. To prove efficiency of the systems a common comparative calculation of technicaleconomical parameters of combined heat and power plants with and without DGU is presented, which is misrepresented as thermodynamic analysis. A «modified» coefficient of fuel heat utilization is used in the capacity of a determinant of thermodynamic efficiency for this type of systems, although the above-mentioned coefficient is not suitable for this purpose and only leads to overstatement of their efficiency factor.
Using DGUs at combined heat and power plants which have rather high consumption of NG and other heat power sources is of no interest for the above plants because of a low electrical power of DGUs: its value is at best 0.6–0.7% of the rated capacity of combined plants. As for implementation of DGUs at low capacity facilities, it seems to be unfeasible because of impossibility to develop the required equipment. Advantages of DGUs stated by some authors are refuted by the fact that all four DGUs used to be operated in the Mosenergo system were decommissioned more than six years ago.