Increasing the efficiency of VV�R atomic power plant units in the period before refueling

KPI ((http://www.ntu-kpi.kiev.ua/) is one of the oldest and biggest technical universities in Ukraine. It was founded in 1898.Prof. D.I. Mendeleyev (inventor of the Periodic Table of Elements) was a chairman of the first examining board in KPI in 1903. World-famous are the names of I.I. Sikorskiy (Russian and American pioneer of aviation in both helicopters and fixed-wing aircraft), S.P. Timoshenko (the father of modern engineering mechanics), S.P. Korolyov (the lead Soviet rocket engineer and spacecraft designer), B.E. Paton (world-known Ukrainian metallurgist and specialist in welding technology), etc. who studied or worked in KPI.Now KPI is the largest university in Ukraine — 28 000 students; 53 bachelor’s, 113 master’s, and 82 Ph.D. programs. 25 % of the students of the technical universities of Ukraine are the students of NTUU “KPI”. In 2011, more than 120 titles of scientific and educational literature were published and 17 scientific periodicals were issued at NTUU “KPI”.KPI scientifically and technically cooperates with numerous international organizations and funds, such as: Ukraine-EU, Ukraine-NATO, International European Innovational Scientific and Technical Program “EUREKA”, IAEA, US Civilian Research and Development Foundation for Former Soviet Union countries (FSU), European Organization for Nuclear Research (CERN), Joint Institute for Nuclear Research (JINR), Organization of Black Sea Economic Cooperation (BSEC), Science and Technology Center in Ukraine (STCU), etc.KPI is leading in preparation of the engineers for nuclear and thermal power plants in Ukraine. Its Heat Power Engineering Faculty includes two Departments to meet the challenge: the Department of Nuclear Power Plants and of Engineering Thermophysics and the Department of Heat-and-Power Engineering Units of Thermal and Nuclear Power Plants. The students learn such courses of Nuclear Engineering program as: Nuclear Power Unit Regulation; Erection, Maintenance, and Adjustment of Nuclear Power Units; Neutron-Physical Simulation of Reactors; NPP Reliability and Safety; Risk Management. Program of Engineering Thermophysics includes the following courses: Numerical Simulation of Thermal and Hydrodynamic Processes; Investigation of Alternative Energy Sources; Optimization of Power Equipment Operation, etc.Copyright © 2012 by ASME

The purpose of the work is to form and discuss the key components of the methodology to obtain the quantitative indicators of the personnel reliability based on the actual long-term operation experience data for a particular power unit. The timeliness of this work and similar studies is based on a simple judgment that the personnel reliability performance at similar units, in the best case, and in associated industries, in the worst case, that is, the reliability of personnel at other industrial facilities, is used to justify the design when designing power plant units. Accordingly, the obtained safety assessments with respect to personnel have nothing to do with the facility the safety of which is justified. This requires respective methods and procedures to update the safety criteria with regard for the actual operation experience, as a minimum, based on the actual reliability of the NPP unit personnel. The key components are presented for shaping the methodology to obtain the quantitative indicators of the personnel reliability based on data of the unit’s long-term actual operation experience. Recommendations and explanations are provided for each of the methodology’s key components, namely: an information model of the methodology, the key indicators and other components are provided. The timeliness of the methodology development is explained making it possible to obtain quantitative indicators based on the nuclear plant unit’s operation experience. An additional methodology is presented to assess the safety of nuclear power plants. A unique notional definition of the nuclear plant personnel reliability, and the procedures to justify the power unit safeguards with regard for the human factor aspects have been proposed. An information model of the methodology is provided and the prospects of its application to improve the safety justification procedure for various components of the nuclear plant units are described. To conclude with, ways are presented for the further evolution of the proposed methodology, and the scope of the methodology and the expected positive effect from its application are described.

In this study, we study and evaluate a zero emission integrated system, as taken from the literature, for coproduction of electricity and methanol. The investigated integrated system has three subsystems: water electrolysis, Matiant power plant (oxy-fuel combustion of pure methane), and methanol production unit. The system and its components are analyzed energetically and exergetically. The rates of exergy destructions, relative irreversibilities, and sustainability indexes of each subunit of each subsystem, as well as the overall system are analyzed to identify the greatest exergy losses and possible future research directions. The total rate of exergy destruction of the overall system is calculated to be around 280 MW. The greatest rate of exergy destruction, therefore the greatest irreversibility, occurs within the power plant unit (about 60 % of the total rate of exergy destruction). The energy efficiencies of electrolysis, power plant, and methanol synthesis unit are found to be 30 %, 76 %, and 41 %, respectively. The exergy efficiencies of electrolysis, power plant, and methanol synthesis unit are found to be 30 %, 64 %, and 41 %, respectively. Depending on the utilization of the heat rejected from the different units of each subsystem, the overall system could have energy and exergy efficiencies up to 68 % and 47 %, respectively.

For Ukraine the realization of available reserves to increase the power of operating power units of nuclear plants is a vital problem the solution of which would allow us to increase electric power output. A special role is also played by economic priorities; in particular an increase in power by 1 kW is ten times cheaper in comparison with the construction of 1 kW of new power facilities. One more factor is the world experience in the field of an increase in the thermal power of operating power units of nuclear power plants. Based on the specified urgency this scientific paper analyzes the international experience gained in the field of an increase in the thermal power of the power units for nuclear power plants and describes the main mechanisms and instrumentation required for the realization of the given modification of nuclear power units in Ukraine. The reserves embedded into the project to enable an increase in the thermal power of power units were represented graphically. Recommendations on the scope of appropriate measures to be taken and substantiations required for the implementation of the appropriate level of an increase in the thermal power of Ukrainian power units with water-moderated water-cooled power reactors VVER-1000 and VVER-440 have been given.

Introduction:Interest in nuclear power as a cleaner and alternative energy source is increasing in many countries. Despite the relative safety of nuclear power, large-scale disasters such as the Fukushima Daiichi (Japan) and Chernobyl (Ukraine) meltdowns are a reminder that emergency preparedness and safety should be a priority. In an emergency situation, there is a need to balance the tension between a rapid response, preventing harm, protecting communities, and safeguarding workers and responders. The first line of defense for workers and responders is personal protective equipment (PPE), but the needs vary by situation and location. Better understanding this is vital to inform PPE needs for workers and responders during nuclear and radiological power plant accidents and emergencies.Study Objective:The aim of this study was to identify and describe the PPE used by different categories of workers and responders during nuclear and radiological power plant accidents and emergencies.Methods:A systematic literature review format following the PRISMA 2020 guidelines was utilized. Databases SCOPUS, PubMed, EMBASE, INSPEC, and Web of Science were used to retrieve articles that examined the PPE recommended or utilized by responders to nuclear radiological disasters at nuclear power plants (NPPs).Results:The search terms yielded 6,682 publications. After removal of duplicates, 5,587 sources continued through the systematic review process. This yielded 23 total articles for review, and five articles were added manually for a total of 28 articles reviewed in this study. Plant workers, decontamination or decommissioning workers, paramedics, Emergency Medical Services (EMS), emergency medical technicians, military, and support staff were the categories of responders identified for this type of disaster. Literature revealed that protective suits were the most common item of PPE required or recommended, followed by respirators and gloves (among others). However, adherence issues, human errors, and physiological factors frequently emerged as hinderances to the efficacy of these equipment in preventing contamination or efficiency of these responders.Conclusion:If worn correctly and consistently, PPE will reduce exposure to ionizing radiation during a nuclear and radiological accident or disaster. For the best results, standardization of equipment recommendations, clear guidelines, and adequate training in its use is paramount. As fields related to nuclear power and nuclear medicine expand, responder safety should be at the forefront of emergency preparedness and response planning.

The problem of selecting the optimal composition of operating units in power plants when planning short-term modes of power systems is a complex problem of nonlinear programming. Its solution usually boils down to determining the starting or stopping units in power plants for each interval of the planning period. Despite the current existence of many methods and algorithms for solving this problem, the issues of their improvement in the direction of increasing the accuracy of calculations and the reliability of convergence of iterative process, taking into account the new conditions of the functioning of power systems, as well as the capabilities of modern computing facilities, remains as an important task. In this paper, we propose a new algorithm for the selection of the composition of operating units in power plants based on a genetic algorithm, which, to a certain extent, meets modern requirements. The solution to the problem is carried out in two stages. At the first stage, generalized energy characteristics of the plants participating in the optimization are constructed. At the second stage, based on optimal coverage of the power system load schedule by all plants according to their obtained generalized energy characteristics taking into account all limiting factors, by the genetic algorithm, the optimal compositions of the operating units are determined. High accuracy of the result is ensured by the direct use of energy characteristics of plants, usually set in a tabular form, and the ability of the genetic algorithm to solve multi-extreme problems without any simplifications.The results of computational experiments, which confirm the high efficiency of the proposed algorithm, are presented.

Large-scale development of nuclear central heating — a radical expansion of a sphere of application, large increase of cost-effectiveness and self-financing of the construction of nuclear sources of energy, increase of their fraction in the base part of the load schedule, and large-scale displacement of fossil fuel — is validated. Suggestions for a program for developing nuclear heat and power plants are examined. It is shown that the power generating units of nuclear heat and power plants must satisfy specific requirements, which requires developing specialized reactor systems. The main technical and economic characteristics of an innovative simplified boiling water reactor VK-300, specially designed for central heating power generating units, the parameters of a central heating power generating unit with VK-300, and the results of validation of investments in the construction of the VK-300 nuclear heat and power plant in Arkhangel’sk are presented.

Signal interfacing between systems and cabinets for a phased I&C safety systems upgrade in nuclear power plants

The article presents the technique of an estimation of efficiency of use of potential heat output of an auxiliary boiler (AB) to improve electric capacity and manoeuvrability of a steam turbine unit of a power unit of a nuclear power plant (NPP) equipped with a water-cooled water-moderated power reactor (WWER). An analysis of the technical characteristics of the AB of Balakovo NPP (of Saratov oblast) was carried out and hydrocarbon deposits near the NPP were determined. It is shown that in WWER nuclear power plants in Russia, auxiliary boilers are mainly used only until the normal operation after start-up whereas auxiliary boiler equipment is maintained in cold standby mode and does not participate in the generation process at power plants. The results of research aimed to improve the systems of regulation and power management of power units; general principles of increasing the efficiency of production, transmission and distribution of electric energy, as well as the issues of attracting the potential of energy technology sources of industrial enterprises to provide load schedules have been analyzed. The possibility of using the power complex NPP and the AB as a single object of regulation is substantiated. The authors’ priority scheme-parametric developments on the possibility of using the thermal power of the auxiliary boilers to increase the power of the steam turbine of a nuclear power plant unit equipped with WWER reactors unit during peak periods, as well as the enthalpy balance method for calculating heat flows, were applied. The surface area of the additional heater of the regeneration “deaerator – high pressure heaters” system and its cost were calculated. On the basis of calculations, it was shown that the additional power that can be obtained in the steam turbine of the NPP with a capacity of 1200 MW due to the use of heat of the modernized auxiliary boiler in the additional heat exchanger is 40.5 MW. The additional costs for the implementation of the heat recovery scheme of the auxiliary boiler at different prices for gas fuel and the resulting system effect were estimated in an enlarged way. Calculations have shown the acceptability of the payback period of the proposed modernization.

The Ignalina nuclear power plant (NPP) Units 1 and 2 are Soviet-designed, RBMK (Reaktor Bolshoi Moschnosti Kipyashchiy), channelized, large power-type reactors. The original-design electrical capacity for each unit was 1500 MW. Unit 1 began operating in 1983, and Unit 2 was started up in 1987. In 1994, the government of Lithuania agreed to accept grant support for the Ignalina NPP Safety Improvement Program with funding supplied by the Nuclear Safety Account of the European Bank for Reconstruction and Development (EBRD). As conditions for receiving this funding, the Ignalina NPP agreed to prepare a comprehensive safety analysis report that would undergo independent peer review after it was issued. The EBRD Safety Panel oversaw preparation and review of the report. In 1996, the safety analysis report for Unit 1 was completed and delivered to the EBRD. Part of the analyses covered anticipated transients without scram (ATWS). The analysis showed that some ATWS scenarios could lead to unacceptable consequences in <1 min. The EBRD Safety Panel recommended to the government of Lithuania that the Ignalina NPP develop and implement a program of compensatory measures for the control and protection system before the unit would be allowed to return to operation following its 1998 maintenance outage. A compensatory control and protection system that would mitigate the unacceptable consequences was designed, procured, manufactured, tested, and installed. The project was funded by U.S. Department of Energy.

There are several risk-sensitive industries-like air traffic, nuclear power generation, dangerous chemical processes, etc. The technical solutions used are usually well approved and widely known; the occasional problems usually originate from the not-careful-enough design, the insufficient risk assessment, the unsatisfactory training and mismanagement. With proper operation and waste management the nuclear fission power is one of the clearest and cheapest energy sources: no gases are emitted during the energy generation and other related preparatory etc. processes. The upcoming nuclear-fusion-based power plants are even more promising; all contamination in these plants will be decayed practically to nil in less than 100 years. Renewable energy sources can play an important, but only a supplementary role, at least for the foreseeable future. Due to historical reasons, the public approval of the fission-based nuclear power is rather low in many countries. On the other hand, we still have to wait for the appearance of significant fusion power at least several decades; and closing this gap the construction of a new generation of NPPs (nuclear power plants) seems to be unavoidable. Construction on the large scale of carbon dioxide emitting conventional power plants operating on fossil fuel seems to be the worst solution, anyway. Even ignoring the CO 2 -related problems, the growing energy needs of the developing Asian countries cannot be satisfied alone with the oil or gas available on the markets. Therefore there are several NPPs already under construction and more contracts are to come. Meanwhile, all over in the USA and Europe the operation of old NPPs are going to be prolonged for another 20-30 years. Slowly, even in Europe the construction of new nuclear power plants are considered, too. The first such Generation 3+ NPP is already under construction in Finland. In all cases, simulation studies and the use of simulators is essential. It is a well known fact and it is widely approved by many scientists and engineers that direct evaluation of different technical designs above a certain complexity level is unthinkable. Careful modelling, model integration, verification and validation is necessary to build the simulation tools and computer codes for the design and real-time simulators are even better for testing and validation of complex industrial processes. The average lifetime of a big nuclear or other power plant exceeds that of its instrumentation and control (I&C) systems several times. Computer based such systems are prone to even faster moral exhaustion.Without extensive simulation the replacement of such systems would cause long-lasting outages resulting in great financial losses. In the paper first I would like to give a survey on the present state of energy production and consumption in the world and after that I would like to summarize the results and practice we used at Paks NPP in Hungary: first in the evaluation of safety studies, then in the working-out of new state-of-art operational procedures, and finally, during reconstruction of the reactor safety system and other I&C Systems, the replacement of which-thanks to the extensive testing and tuning performed using the full-scope replica simulator-was completed during the regular re-fuelling outage of the NPP units.

Authors

The emergency compressed air production system is a part of the compressed air production system of the nuclear power plant. Its function is to provide the necessary compressed air to the nuclear island when the main air compressor fails and cannot provide compressed air. Each unit of the nuclear power plant has two emergency air compressors to provide backup air source for the compressed air distribution system for instrumentation. Under normal working conditions, one emergency air compressor is in the basic load state and the other is in the standby state. The two emergency air compressors will automatically start according to the degree of pressure drop of the compressed air production system. The purpose of the emergency backup function of the emergency air compressor is to verify that the two air compressors will start up as the system pressure drops in different states, and to verify the operating parameters of the two emergency air compressors. The test period is one week. Periodic testing is an important activity for nuclear power plants to ensure the availability of equipment that performs important functions. However, periodic testing exceeding a certain frequency may reduce the safety of the power plant and increase the unnecessary burden of the power plant. At present, PSA has been widely used in nuclear power plant operation guidance, maintenance rules and many other fields, PSA has developed into an important tool for safety assessment and decision-making. With the development of PSA technology, the risk-oriented model combining probability theory and determinism has also been applied in the optimization of the periodic test cycle of nuclear power plants, so that the resource allocation of power plants can be optimized under the premise of ensuring sufficient safety of nuclear power plants. Improve regulatory and operational efficiency. This paper will take the emergency compressed air production system of Fangjiashan Nuclear Power Plant (FSJ NPP) as an example to introduce the application method of the risk-oriented periodic test optimization method.

We present the data of autoclave testing of 10GN2MFA and 08Kh18N10T steels for cyclic crack-growth resistance in reactor borated water at a temperature of 300°C. We tested standard 25-mm-thick specimens for two values of the load ratio equal to 0.2 and 0.7. The loading frequency of specimens in the autoclave did not exceed 0.0167 Hz. We propose a model and a procedure of numerical evaluation of the increments of crack length according to the mechanisms of corrosion-fatigue and static corrosion cracking under the conditions of their combined action based on the analysis of principal characteristics of structural materials. Unlike the method based on the use of the Paris equation proposed by foreign standards, the method developed in the present work is more general and informative. Moreover, it includes the method used in standard specifications as a special case and enables one to explain the premature fracture of collectors of steam generators at the South-Ukrainian Nuclear Power Plant and other elements of power-generating units of the nuclear power plants. It is shown that, in the absence of corrosion-fatigue cracking, power-generating units of nuclear power plants can operate without emergency shutdowns for the entire service life. In the case where the heat carrier is polluted to a level sufficient for the initiation of the mechanism of static corrosion cracking, the service life of units to the time where the crack attains its critical size sharply decreases. We propose to improve the systems of water supply and perform continuous monitoring of the controlled parameters of the heat carrier and, in particular, of the contents of admixtures promoting the static corrosion cracking of steels.

Economic evaluation of hydrogen production in second and third units of Bushehr nuclear power plant regarding future need of nuclear fission technology