The influence of operational and water chemistry parameters on the deposits of corrosion products on fuel assemblies at nuclear power plants with VVER reactors

The phenomenon involving a growth of pressure drop in the reactor core and redistribution of deposits in the reactor core and primary coolant circuit of a nuclear power station equipped with VVER-440 reactors is considered. A model is developed, the physicochemical foundation of which is based on the dependence of corrosion product transfer on the temperature and pH _t value of coolant and on the correlation between the formation rate of corrosion products (Fe) (after subjecting the steam generators to decontamination) and rate with which they are removed from the circuit. The purpose of the simulation carried on the model is to predict the growth of pressure drop on the basis of field data obtained from nuclear power installations and correct the water chemistry (by adjusting the concentrations of KOH, H₂, and NH₃) so as to keep the pressure drop in the reactor at a stable level.     

Lines of improving the economic efficiency of nuclear power stations equipped with VVER reactors

The economic efficiency of measures on optimizing technical solutions for the equipment of nuclear power stations—specifically, on improving turbine units—is shown.     

Thermal and nuclear power plants: Competitiveness in the new economic conditions

In recent years, the conditions of development and functionality of power generating assets have notably changed. Considering the decline in the price of hydrocarbon fuel on the global market, the efficiency of combined-cycle gas-turbine plants in the European part of Russia is growing in comparison with nuclear power plants. Capital investments in the construction of nuclear power plants have also increased as a result of stiffening the safety requirements. In view of this, there has been an increasing interest in exploration of effective lines of development of generating assets in the European part of Russia, taking consideration of the conditions that may arise in the nearest long-term perspective. In particular, the assessment of comparative efficiency of developing combined-cycle gas-turbine plants (operating on natural gas) in the European part of Russia and nuclear power plants is of academic and practical interest. In this article, we analyze the trends of changes in the regional price of hydrocarbon fuel. Using the prognosis of net-weighted import prices of natural gas in Western European countries—prepared by the International Energy Agency (IEA) and the Energy Research Institute of the Russian Academy of Sciences (ERIRAS)—the prices of natural gas in the European part of Russia equilibrated with import prices of this heat carrier in Western Europe were determined. The methodology of determining the comparative efficiency of combined-cycle gas turbine plants (CCGT) and nuclear power plants (NPP) were described; based on this, the possible development of basic CCGTs and NPPs with regard to the European part of Russia for various scenarios in the prognosis of prices of gaseous fuel in a broad range of change of specific investments in the given generating sources were assessed, and the extents of their comparative efficiency were shown. It was proven that, at specific investments in the construction of new NPPs in the amount of 5000 dollars/kW, nuclear power plants in the European part of Russia become less efficient as compared to CCGTs operating on natural gas.     

Studying the effect the parameters of steam power cycle have on the economic efficiency and reliability of three-loop combined-cycle plants with steam reheating

We consider the effect the temperatures and pressures in the high- and intermediate-pressure loops have on the economic characteristics of the heat-recovery boiler, steam turbine cylinders, and steam turbine unit of the combined-cycle plant and on the final content of moisture in the steam turbine.     

Introduction of water chemistry regimes with ethanolamine metering at nuclear power plants equipped with VVER-type reactors

The results of introduction of water chemistry with ethanolamine metering in the feedwater at unit No. 2 of the Balakovo NPP are presented. Along with the data obtained in the course of operational monitoring of the working medium of the secondary coolant circuit, the results of studying of contamination of the tube system of steam generators are presented and analyzed.     

Thermohydraulic investigations of increasing the burnup of nuclear fuel in fast-neutron reactors

We present the results from experimental and calculated investigations of the effect the deformation of fuel assembly casings, fuel rod bundle, and single fuel rods in the cores of fast-neutron reactors has on their temperature conditions. It is shown that the distortion of a fuel assembly (FA) is determined to a considerable extent by temperature nonuniformities in it, which in the final analysis affects the burnup of nuclear fuel.     

Determining the economic efficiency of combined and separate schemes of power supply on the basis of nuclear and fossil fuel

The economic efficiency of a combined power supply system constructed on the basis of nuclear cogeneration sources and natural gas-fired peak-standby boiler houses is analyzed in comparison with separate schemes comprising nuclear condensing power stations and district boiler houses operating on natural gas.     

The problem of optimizing the water chemistry used in the primary coolant circuit of a nuclear power station equipped with VVER reactors under the conditions of longer fuel cycle campaigns and increased capacity of power units

It is shown that the optimal water chemistry of the primary coolant circuit must be substantiated while introducing measures aimed at increasing the power output in operating power units and for the project called AES-2006/AES TOI (a typical optimized project of a nuclear power station with enhanced information support). The experience gained from operation of PWR reactors with an elongated fuel cycle at an increased level of power is analyzed. Conditions under which boron compounds are locally concentrated on the fuel rod surfaces (the hideout phenomenon) and axial offset anomaly occurs are enlisted, and the influence of lithium on the hideout in the pores of deposits on the surfaces of fuel assemblies is shown.     

Problems and prospects connected with development of high-temperature filtration technology at nuclear power plants equipped with VVER-1000 reactors

Results of work on restoring the service properties of filtering material used in the high-temperature reactor coolant purification system of a VVER-1000 reactor are presented. A quantitative assessment is given to the effect from subjecting a high-temperature sorbent to backwashing operations carried out with the use of regular capacities available in the design process circuit in the first years of operation of Unit 3 at the Kalinin nuclear power plant. Approaches to optimizing this process are suggested. A conceptual idea about comprehensively solving the problem of achieving more efficient and safe operation of the high-temperature active water treatment system (AWT-1) on a nuclear power industry-wide scale is outlined.     

Studying the vibration and random hydrodynamic loads on the fuel rods bundles in the fuel assemblies of the reactor installations used at nuclear power stations equipped with VVER reactors

Random hydrodynamic loads causing vibration of fuel rod bundles in a turbulent flow of coolant are obtained from the results of pressure pulsation measurements carried out over the perimeter of the external row of fuel rods in the bundle of a full-scale mockup of a fuel assembly used in a second-generation VVER-440 reactor. It is shown that the turbulent flow structure is a factor determining the parameters of random hydrodynamic loads and the vibration of fuel rod bundles excited by these loads. The results from a calculation of random hydrodynamic loads are used for estimating the vibration levels of fuel rod bundles used in prospective designs of fuel assemblies for VVER reactors.     

The comparative effectiveness of serving peak loads in the variants of providing nuclear power plants with a base load

The present paper reports the results of an investigation into the effectiveness of serving peak loads in the variants of providing nuclear power plants with a base load through unloading condensing power plants, combined heat and power (CHP) plants, combined-cycle thermal power plants during night-time off-peak hours, the use of the off-peak electric power for power and heat supply, and water electrolysis with the use of hydrogen and oxygen for production of the peak electric power, as compared with the variant of the development of pumped storage hydropower plants.     

Prospects for development of nuclear power stations equipped with VVER reactors

The prospects for further development in Russia of nuclear stations equipped with water-cooled water-moderated reactors are considered.     

核电厂DCS供电电源设计研究

借鉴其他核电项目的设计思路,提出了一种新的直流系统设计方案,能够结合核电厂厂用电系统的特点,为DCS提供安全、可靠的双路供电电源。     

Error of measurement under technical diagnostics of energetic power plants

The processes of gaining and transmitting information that permit one to conduct technical diagnostics of electrical networks and power-supply systems (ENPSS) are investigated. Recommendations of how to decrease the errors in the systems of measurement, transformation, recoding, and information transmitting during technical diagnostics are given.     

Specific features of external heat and mass transfer in the vibration apparatuses used for regenerating spent fuel from nuclear power plants

We present experimental data on the coefficients of heat and mass transfer for freely floating bodies simulating fragments of cladding and large conglomerates of fuel, as well as on the local coefficients of heat and mass transfer over the bed height, which point to high intensity of heat and mass transfer processes that take place in the elements of vibration apparatuses intended for subjecting spent fuel from nuclear power plants to oxidative recrystallization.     

具有大型核电站的电力系统的安全策略和措施

针对大型核电站对电网的特殊要求，论述核电站厂用电系统的特点，并对厂外电源对核电安全的重要性进行讨论，指出具有核电站的电网在运营时必须采取的安全策略和措施。以广东电网和大亚湾核电站为例，介绍应注意的问题及其采取的措施。     

Comparative analysis of cooling systems for energy equipment of combined heat and power plants and nuclear power plants

In the 20th century, the thermal power engineering in this country was oriented toward oncethrough cooling systems. More than 50% of the CHPP and NPP capacities with once-through cooling systems put into operation before the 1990s were large-scale water consumers but with minimum irretrievable water consumption. In 1995, the Water Code of the Russian Federation was adopted in which restrictions on application of once-through cooling systems for newly designed combined heat and power plants (CHPPs) were introduced for the first time. A ban on application of once-through systems was imposed by the current Water Code of the Russian Federation (Federal law no. 74-FZ, Art. 60 Cl. 4) not only for new CHPPs but also for those to be modified. Clause 4 of Article 60 of the Water Code of the Russian Federation contravenes law no. 7-FZ “On Protection of the Environment” that has priority significance, since the water environment is only part of the natural environment and those articles of the Water Code of the Russian Federation that are related directly to electric power engineering, viz., Articles 46 and 62. In recent decades, the search for means to increase revenue charges and the economic pressure on the thermal power industry caused introduction by law of charges for use of water by cooling systems irrespective of the latter’s impact on the water quality of the source, the environment, the economic efficiency of the power production, and the living conditions of the people. The long-range annual increase in the water use charges forces the power generating companies to switch transfer once-through service water supply installations to recirculating water supply systems and once-through–recirculating systems with multiple reuse of warm water, which drastically reduces the technical, economic, and ecological characteristic of the power plant operation and also results in increasing power rates for the population. This work comprehensively substantiates the demands of power engineering specialists that the ban on development and construction of once-through service water supply systems should be lifted and the proposals for new parameters, e.g., temperature and back pressure, for designing low-potential equipment of steam-gas and steam-power plants.     

燃气-蒸汽联合循环发电机组轴系配置的思考

燃气-蒸汽联合循环发电机组因高效、节能、环保而越来越受到重视,为此,从我国当前大力发展燃气-蒸汽联合循环发电机组的实际情况出发,全面分析联合循环机组轴系的配置型式及其影响,重点比较了单轴和多轴“2拖1”机组在设备投资、占地面积、建设周期、起动停机、功率和效率、检修和控制系统方面的优缺点,为燃气-蒸汽联合循环发电新机组建设的轴系配置提供参考。     

The technical and economic principles and lines of development of nuclear district heating cogeneration

We consider the social and economic requirements, technical background, and possible lines for future development of nuclear district heating cogeneration for the period leading up to 2030 taking into account the way in which the structure of Russia’s fuel and energy complex is formed.