Large Nuclear Power Plants Research Articles

The Future of Microreactors: Technological Advantages, Economic Challenges, and Innovative Licensing Solutions with Blockchain

This study details the unique advantages and challenges associated with microreactors. Microreactors offer rapid installation and flexible application capabilities, meeting energy needs in remote and inaccessible areas. Unlike large nuclear power plants, they can be set up and start generating energy within a few days, resulting in significant time and cost savings. Their small size and modular design reduce capital and operational costs while enhancing economic competitiveness. However, some technical and regulatory challenges persist for the widespread adoption of microreactors. Licensing processes designed for large nuclear power plants may delay the widespread adoption of microreactors. Blockchain technology can play a crucial role in overcoming these challenges by providing transparency and reliability in the licensing processes. The operational settings of microreactors should be carefully considered, and regulatory authorities must be effectively designated. Collaboration and coordination are vital in this process. Consequently, the flexibility and innovative solutions offered by microreactors highlight the importance of future research to examine the optimal conditions for their use.

Enhancing equipment qualification testing facility for nuclear power plants: Achieving rapid temperature and pressure increase during design basis events

The present study focuses on the development of an equipment qualification (EQ) testing facility for Class 1E equipment in nuclear power plants (NPPs), emphasizing the need to ensure safety functions under design basis events (DBEs). The Republic of Korea (ROK) has implemented international safety standards to support large NPP projects, necessitating the development of domestic EQ testing facilities to reduce the dependence on foreign facilities. To address this need, herein, a specialized facility capable of simulating harsh DBE conditions that may occur in NPPs in ROK was constructed. Through exhaustive research, target temperature and pressure profiles were developed for pressurized water reactors, and a superheated steam injection technique was devised for rapid temperature and pressure changes. The present study contributes to the advancement of domestic EQ testing capabilities, achieving up to 230 °C and 700 kPa within 30 s.

Site effect on seismic response of buried nuclear power plant structure

The development of multifunctional, multipurpose small modular next generation nuclear reactors has become a trend in designing small-scale nuclear power stations. In this study, taking a new next-generation buried nuclear power structure as the target structure, a 3D finite element model of the site-nuclear power plant structure system was established, and its response at different sites was studied. Using the internal substructure method, this study initially explored the impact of earthquake input and artificial boundary locations on the structural response. The results indicate that the internal substructure method enhances computational efficiency without compromising accuracy. For this model, it is recommended to input earthquake motion close to the structure, set the lateral boundary location to three times the width of the structure, and set the bottom boundary location to two times the depth of the structure. Subsequently, an investigation into the response of the structure at varying site wave velocities is conducted. The results show that as the wave velocity increases, the acceleration response intensifies, while the displacement response diminishes. However, the relationship is nonlinear; the response exhibits less variation with increasing site wave velocity. The seismic response of a structure is profoundly influenced by site conditions, emphasizing the imperative need for careful consideration of specific site characteristics in seismic analyses. In addition, the response pattern of the overall structure is significantly different from that of conventional large surface-sited nuclear power plants, and further research should be conducted on the seismic response characteristics of buried nuclear power plants.

Escalation Ladder and the Game of Chances in the Ukraine war of 2022

The paper refers to the most recent developments during the 2022–2023 Ukraine war, analysed from the perspective of selected insights derived from deterrence studies, most notably the escalation ladder. The reason for the publication is to point out dangerous escalatory steps in the context of Putin’s Russia-Ukrainian war, including the abolishment of strategic arms control and tactical nuclear weapons deployment in the EU neighbourhood. V. Putin’s regime’s steps towards seizure or control of Ukraine’s largest nuclear power plant were discussed internationally as a severe humanitarian hazard. The pre-1989 deterrence debate could add a vital research perspective missing in the analytic frames of the New Cold War. Notably, the developments of the 2023 conduct of the Ukraine war with the support of the West countering the impact of a nuclear crisis scenario (tactical arsenal employment) could be analysed in the context of earlier concepts of limited war (1960s), as well as further elaborations on conditions of mutual vulnerability.

Application of the fast 3D simplified simulation method for the large CAP1400 nuclear island evaporator based on the coupled source term method

As for the evaporator of the large CAP1400 nuclear power plant, it has a large volume with numerous tubes along with the complex flow heat transfer phenomenon. The traditional direct simulation method usually takes a lot of time and computing resources to obtain the flow heat transfer data. To solve the problem, a fast simulation method established on the porous medium source term was herein proposed. In this simplified simulation method, the complex evaporator model is replaced with the porous medium model, where the derived heat and momentum source terms are added into the governing equation to control the heat flows. Five kinds of simplified evaporator models with different numbers of pipes were set to be the research objects, the internal flows inside the evaporator were studied with the traditional direct simulation method and the newly proposed simplified simulation method. Via comparative analysis, it can be found that: 1) The newly proposed simplified simulation method accurately captures the distribution characteristics of pressure, temperature, and entropy production in the evaporator, serving as a viable alternative to traditional direct simulation methods. Specifically, the average simulation errors for inlet-outlet pressure difference and temperature difference are both less than 5 % and 7 %, respectively. 2) The newly proposed simplified simulation method can capture the mutual interference effects between the evaporator and the nuclear main pump. When the evaporator is connected in series with the main nuclear pump, the average head of the main pump increases by 0.34 m, while the efficiency decreases by an average of 0.34 %. The average simulation errors of the simplified simulation method are 0.06 m and 0.13 %, respectively. 3) The application of the simplified simulation method leads to a significant 85 % decrease in the average computational cost for evaporator calculations and a notable 36 % decrease for combined calculations of the evaporator and main pump. The study here is expected to provide technique support for the simulation and evaluation of the large nuclear island.

The commoditization of civil nuclear power.

The commoditization of nuclear power through the factory production of sealed micro-power units within a digitally enabled holistic assurance framework is described. This would revolutionize nuclear power-plant design, construction, operation and decommissioning through a paradigm shift to manufacture-operate-remove-recycle (MORR). The potential impact of recent research on an integrated nuclear digital environment for large bespoke nuclear power plants and the design, build and operation of fusion power plants using such a digital environment is explored. These strands are interwoven to discuss the technical, economic and socio-political implications of MORR in the context of micro-reactors and to consider the potential evolution of safeguarding issues based on a digital assurance framework that leads to type approvals. Commoditization of nuclear power would lower costs in line with offshore wind and the output from a single production line in a factory could replace a third of current fossil fuel-based electricity generation in the UK over a 15-year period, making a significant contribution to achieving zero greenhouse gas emissions. The challenges associated with the changes in culture, both in the nuclear industry and in society, as well as the technology gaps, that need to be addressed in realizing this paradigm shift are identified and discussed.

Nuclear Aspects of the Russia-Ukraine War and its Implications for Nepal

Nearly two years old Russia-Ukraine war seems to go on for a long period. The United States and European Union are supporting Ukraine’s offensive to regain their lost land. The Russian threat to use nuclear bombs at the outset has taken the world by great surprise. The use of a megaton nuclear bomb could lead to unimagined catastrophe killing a billion people, and a nuclear winter could set in leading to a worldwide famine that could kill millions more. The nuclear watchdog of the United Nations - the International Atomic Energy Agency, is keeping track of Europe’s largest nuclear power plant in Ukraine. Nuclear-related international treaties are fast becoming ineffective and World War III could be possible. This war is, however, coming to a stalemate. Peace initiatives taken are ineffective so far. This war must end soon and nuclear weapons should remain as deterrence and should not and never be used to save mankind.

LARCalc, a tool to estimate sex- and age-specific lifetime attributable risk in populations after nuclear power plant fallout

A tool called LARCalc, for calculating the radiological consequences of accidental large scale nuclear power plant releases based on estimates of 137Cs ground deposition, is presented. LARCalc is based on a previously developed models that has been further developed and packaged into an easy-to-use decision support tool for training of decision makers. The software visualises the radiological impact of accidental nuclear power plant releases and the effects of various protective measures. It is thus intended as a rapid alternative for planning protective measures in emergency preparedness management. The tool predicts projected cumulative effective dose, projected lifetime attributable cancer risk, and residual dose for some default accidental release scenarios. Furthermore, it can predict the residual dose and avertable cumulative lifetime attributable risk (LAR) resulting from various protective measures such as evacuation and decontamination. It can also be used to predict the avertable collective dose and the increase in cancer incidence within the specified population. This study presents the theoretical models and updates to the previous models, and examples of different nuclear fallout scenarios and subsequent protective actions to illustrate the potential use of LARCalc.

Design of heat pipe cooled microreactor based on cycle analysis and evaluation of applicability for remote regions

In spite the efforts to specify the design of heat pipe cooled microreactors, there are lack of conclusive information on microreactors based on cycle analysis. To provide a design guideline for power conversion systems and management, large nuclear power plants (NPPs) were compared in terms of electricity transmission and distribution (T&D) losses and the microreactors were assessed for transportability. To this end, a cycle code was developed, and a thermodynamic analysis and an economic evaluation were conducted. Two different operating conditions with a maximum cycle efficiency of 52.0% and a minimum levelized cost of electricity (LCOE) of 81.82 USD/MWh were derived using the developed code. The best economic microreactor cycle condition was compared with a commercial large NPP. When considering T&D losses, the microreactor seemed more economical if operated for more than 4.3y in Hungary, where the T&D losses are high, and for 13.8y in Germany, where the electricity cost is high. However, the microreactor is more economical than the large NPP only for short period because the designed lifetime of microreactors is currently being investigated. We also designed small power generation systems for microreactor’s transportability; the small power generation systems with the microreactor demonstrated better economics compared with other small power generation systems when using oil, ammonia, and Liquefied Natural Gas (LNG) as fuels to evaluate the availability of the microreactor in the remote regions. The findings indicate that the microreactor could be more economical when generating the same amount of electricity compared to that using power generation systems if the detailed designs satisfy the design points developed from the cycle analysis.

What is the future of nuclear power in Ukraine? The role of war, techno-economic drivers, and safety considerations

The TIMES-Ukraine energy system model is used to explore the future of nuclear power plants (NPPs) under an ambitious climate policy scenario, achieving net zero greenhouse gas emissions in 2050. Varying techno-economic (construction costs and capacity factors for NPPs, capital costs for solar and wind), policy (ban on construction or extension of NPPs), and macroeconomic (alternative economic recovery trajectories) factors are considered. The difference in the techno-economic assumptions for nuclear power generation has a very moderate impact on the total system costs (TSC) of the energy transition, as their variation (positive or negative change) does not exceed 0.1%–0.2% relative to the default case. Policy decisions on restricting nuclear power generation could have a more substantial impact, as TSC increase by 4–5 billion USD (0.6%–0.9%) over the 2020–2050 period under the most restrictive case. In terms of the economic viability of various NPPs, we find small modular reactors to be more competitive than large NPPs due to the higher availability factor. Overall, in terms of developing new NPP capacities, policymakers can consider alternative futures for this technology without major implications for the energy transition costs, as retired NPPs can be substituted by alternative generation technologies in a cost-competitive manner.

THE DEVELOPMENT STRATEGY OF UKRAINE'S ENERGY SYSTEM AND THE PLACE OF SMALL MODULAR REACTORS IN IT

The paper describes the characteristics of small modular reactors (SMR), their differences from existing nuclear power plants and the features of their use in modern hybrid electric power systems in combination with renewable energy sources and Nuclear Renewable Hybrid Energy System (NRHES) electricity storage, their advantages and problems of use in the future power system of Ukraine. Prospects for cooperation in this area with companies from the United States of America were considered. Small modular SMR reactors are suitable for electrical systems of various capacities, their modular system allows flexibility and speed of construction, reduces capital investment needs and eases financing requirements. The smaller size and variety of reactors can also mean that they can be built in locations not traditionally suitable for large nuclear power plants and, importantly, near energy-intensive industries or remote communities, i.e. as elements of distributed generation. They can ensure a reliable supply of not only electricity, but also heat. SMRs can also be deployed at decommissioned coal-fired power plants. Taking advantage of existing infrastructure, including switchgear and coal-fired turbines, could reduce SMR construction costs and avoid the need to add new transmission lines from these facilities. Problems with the implementation of such networks are revealed. Attention was drawn to the increased complexity of the system in connection with the use of various sources of generation and processes of distribution and consumption of electricity. The main technical characteristics, features of the reactor design, the station building, safety systems and control systems are given. The study concludes that SMRs have significant advantages for use in modern networks, due to their modular design and modular deployment, to meet a variety of power switching and scaling requirements.

Энергетический кризис в странах Центральной Азии и перспективы их сотрудничества с Россией

The Central Asian countries, against the background of the rapid growth of electricity and energy consumption in the conditions of the systemic aging of the energy generating infrastructure, have been facing a systemic energy crisis for the past few years. In fact, today all the countries of the region have already overcome the energy “Chubais cross”, when electricity generation in the region and the extraction of energy resources are insufficient for the growing demand of consumption. All this creates a situation when the Central Asian countries face the need to adopt and implement a comprehensive, advanced program for the development of the energy industry, using the full range of opportunities. In the current geopolitical situation, Russia can become the main partner for the countries of the region to overcome the energy crisis by intensifying cooperation in the gas sector with the reversal of the Central Asia-Center gas pipelines, with the construction of at least two large nuclear power plants and the implementation of mini-reactors, as well as the use of the potential of “green” energy.

DETERMINATION OF POTENTIAL AREAS OF INFLUENCE ON THE ROMANIAN TERRITORY OF UKRAINIAN NUCLEAR POWER PLANTS IN THE CONTEXT OF THE CRISIS GENERATED BY THE RUSSIAN-UKRAINIAN CONFLICT

In the context of the crisis generated by the Russian-Ukrainian conflict, radiological situation forecasts were made within the National Institute of Research and Development for Physics and Nuclear Engineering "Horia Hulubei" (IFIN-HH) for all nuclear power plants in Ukraine. Therefore, the resident decision support software systems for radiological and nuclear emergencies were used, with the main purpose of identifying potential areas of influence on the territory of Romania generated by Ukrainian power plants, as consequence of military actions. In the absence of pertinent and confirmed information, two hypothetical scenarios were considered by which the radioactive material could be dispersed into the atmosphere, for which appropriate accident source terms were built, using methods validated and approved by the international organizations in the field. The monitoring of the radiological situation of the Ukrainian nuclear power plants was carried out over a period of several months starting from the first day of the conflict outbreak. In the paper are presented comparative results obtained with two software systems for a representative case at the Zaporozhe Nuclear Power Plant, the largest nuclear power plant in Europe, situated in the center of several disputes.

Relationship between Water Use and Energy Generation from Different Power Generation Types in a Megacity Facing Water Shortages: A Case Study in Shenzhen

Using less water to generate more power is a goal of the worldwide power industry, but this is difficult to achieve because of the lack of long-term, operational data-based studies. This challenge is especially severe for megacities facing water shortages. This study used long-term data (2005–2015) from Shenzhen, a megacity of over 20 million people that faces severe water shortages, to determine the relationship between water and energy for different types of power generation. It was found that power generation consumed huge amounts of water and that cooling water was the biggest water use category. Smaller power plants, such as the Yueliangwan power plant, which uses the closed cooling method, consume 2.36 million m3 of tap water per year, equivalent to the water supply of a small reservoir. However, larger power plants, such as the Mawan power plant and Dayawan nuclear power plant (using the open cooling method), use 0.92 and 3.42 billion m3 of seawater for cooling every year, respectively, equivalent to about 60% and 200% of the total annual water supply in Shenzhen, respectively. Therefore, large thermal power plants and nuclear power plants should be built in coastal areas with rich water resources rather than in arid or semi-arid areas. Additionally, the water use efficiency of nuclear power plants was found to be 0.22 m3/kWh, which was significantly lower than that of coal-fired power plants (0.10 m3/kWh) and gas-fired power plants (0.09 m3/kWh). Third, the water use efficiency of the closed cooling method was ten times higher than that of the open cooling method. Therefore, the closed cooling method is suitable for power plants constructed in areas without rich water resources. These results are useful for balancing the water and energy demands in the changing world.

Direct and indirect health effects of the nuclear power plant disasters: a review for health care professionals

Background: Nuclear power plants are deeply integrated into our society. They possess substantial risk for major disasters. Two of the worst-categorized nuclear power plant disasters were Chernobyl and Fukushima, emitting large amounts of radioactive materials and required mass evacuations in neighboring areas. Methods: This is a rapid review of the literature. We searched PUBMED and Medline for original studies of all large nuclear power plant disaster information documented in literature. Results: Eighty-three publications were identified in the review. The results are summarized in categories based on direct health effects such as immediate health effects, indirect health effects related to evacuation, cancer, behavioral effects and environmental effects like proliferation of wildlife and other infectious diseases. Conclusion: Nuclear power plant disasters have a great impact on human health including increased rates of cancer, behavioral and psychosocial problems, and evacuation related problems. These disasters can lead to major environmental impact, specifically on wildlife, resulting in unanticipated health consequences for local populations. In this review, we describe these consequences of nuclear power plant disasters as they apply to local health care workers.

Nuclear Power as an Option in Electrical Generation Planning for Small Economy and Electricity Grid

Implementing a NPP in countries with relatively small total GDP (small economy) and usually with small electricity grid face two major problems and constrains: the ability to obtain the considerable financial resources required on reasonable terms and to connect large NPP to small electricity grid. Nuclear generation financing in developing countries involves complex issues that need to be fully understood and dealt with by all the parties involved. Besides conventional approaches for financing power generation projects in developing countries, recently some alternative approaches for mobilizing financial resources are developed. The safe and economic operation of a nuclear power plant (NPP) requires the plant to be connected to an electrical grid system that has adequate capacity for exporting the power from the NPP, and for providing a reliable electrical supply to the NPP for safe start-up, operation and normal or emergency shut-down of the plant. Connection of any large new power plant to the electrical grid system in a country may require significant modification and strengthening of the grid system, but for NPPs there may be added requirements to the structure of the grid system and the way it is controlled and maintained to ensure adequate reliability. Paper shows the comparative assesment of NPP adn differrent base load technologies as an option in electrical generation planning for small economy and electricity grid.

Nuclear Power Industry of the USSR Far East: Plans and Problems of Creating an Industry

Introduction. The article discusses the plans and identifies the problems of creating a nuclear power industry in the Far East of the USSR in 1960–1991, reveals the historical reasons for the development of regional projects of nuclear power plants, and determines the conditions for their implementation. Materials and Methods. The study is based on a corpus of unpublished sources, including declassified documents found in federal and regional archives. The study uses a state-centered and regional approach, as well as traditional historical and historical-economic methods. Results. Planning for the creation of a nuclear power industry in the Far East began in the late 1950s – early 1960s during the preparation of long-term plans for the economic development of the region. In 1966–1976 the first experimental low-power nuclear power plant – Bilibino NPP in Chukotka was built. Since the early 1970s projects of two large nuclear power plants were developed, in the mid-1980s the USSR government included them in the programs of economic development of the region. Discussion and Conclusion. There were no conditions for the creation of a nuclear power industry in the Far East, when the USSR economy was in crisis. Problems such as the weak construction industry of the Ministry of Energy of the USSR, the material and technical insecurity and underfunding of the facilities it built, the shortage of labor resources and qualified personnel, did not allow the construction of nuclear power plants in the Far East to be launched. In the late 1980s the Far Eastern public after the accident at the Chernobyl nuclear power plant negatively perceived such projects. With the collapse of the USSR and the fall of the regional industrial complex, the problem of an acute shortage of energy resources that regional nuclear power plants had to solve was smoothed out. At present, there is no such problem in the energy supply of the Far East.

Change of Thinking, Molten Salt Reactor (MSR)

A loss of coolant in a nuclear power plant using solid nuclear fuel can cause a severe nuclear accident, surpassing a design-basis accident, and may include a meltdown and subsequent steam and hydrogen explosion leading to a major release of radioactive material to the environment. A molten salt reactor (MSR), one of the six concepts for a Generation-IV non-pressurized water reactor, utilizes liquid fuel in which the coolant and nuclear fuel are integrated. The integration of the fuel and coolant is fundamentally safe from severe accidents caused by a loss of coolant. Because an MSR operates at atmospheric pressure and high temperature compared to pressurized water reactors, the reactor structure is simple and thermal efficiency is excellent. An MSR can be deployed at any scale from a small micro-reactor to a large commercial nuclear power plant. At a time when the role of nuclear power is growing dramatically more significant for achieving “2050 Carbon Neutrality”, the MSR technology draws attention due to its superior safety and efficiency as well as an expectation that can resolve the spent nuclear fuel issue. This article briefly introduces the characteristics and the R&D status of MSRs.

Sodium-cooled Small Modular Reactors

Amid expectations for nuclear power as a carbon-free energy source are growing to prepare for climate change, deploying efforts for small modular reactors (SMRs) are being actively carried out for the application area to which existing large nuclear power plants are not proper to contribute. Sodium-cooled SMRs are also being developed as one of the candidates to lead the SMR market in the future. This manuscript introduces the background and history of the development of sodium-cooled fast reactors, and the current status of development of Sodium-cooled SMRs and microreactors that are being developed based on them.

Numerical and Experimental Investigation of a Velocity Compounded Radial Re-Entry Turbine for Small-Scale Waste Heat Recovery

The energy industry must change dramatically in order to reduce CO2-emissions and to slow down climate change. Germany, for example, decided to shut down all large nuclear (2022) and fossil thermal power plants by 2038. Power generation will then rely on fluctuating renewables such as wind power and solar. However, thermal power plants will still play a role with respect to waste incineration, biomass, exploitation of geothermal wells, concentrated solar power (CSP), power-to-heat-to-power plants (P2H2P), and of course waste heat recovery (WHR). While the multistage axial turbine has prevailed for the last hundred years in power plants of the several hundred MW class, this architecture is certainly not the appropriate solution for small-scale waste heat recovery below 1 MW or even below 100 kW. Simpler, cost-effective turbo generators are required. Therefore, the authors examine uncommon turbine architectures that are known per se but were abandoned when power plants grew due to their poor efficiency compared to the multistage axial machines. One of these concepts is the so-called Elektra turbine, a velocity compounded radial re-entry turbine. The paper describes the concept of the Elektra turbine in comparison to other turbine concepts, especially other velocity compounded turbines, such as the Curtis type. In the second part, the 1D design and 3D computational fluid dynamics (CFD) optimization of the 5 kW air turbine demonstrator is explained. Finally, experimentally determined efficiency characteristics of various early versions of the Elektra are presented, compared, and critically discussed regarding the originally defined design approach. The unsteady CFD calculation of the final Elektra version promised 49.4% total-to-static isentropic efficiency, whereas the experiments confirmed 44.5%.