It is well known that electrical-power generation plays the key role in advances in industry, agriculture, technology, and standard of living. Also, strong power industry with diverse energy sources is very important for a country's independence. In general, electrical energy can be mainly generated from: (1) nonrenewable energy sources (75.5% of the total electricity generation) such as coal (38.3%), natural gas (23.1%), oil (3.7%), and nuclear (10.4%); and (2) renewable energy sources (24.5%) such as hydro, biomass, wind, geothermal, solar, and marine power. Today, the main sources for electrical-energy generation are: (1) thermal power (61.4%)—primarily using coal and secondarily using natural gas; (2) “large” hydro-electric plants (16.6%); and (3) nuclear power (10.4%). The balance of the energy sources (11.6%) is from using oil, biomass, wind, geothermal, and solar, and has visible impact just in a few countries. This paper presents the current status of electricity generation in the world, various sources of industrial electricity generation and role of nuclear power with a comparison of nuclear-energy systems to other energy systems. A comparison of the latest data on electricity generation with those several years old shows that world usage of coal, gas, nuclear, and oil has decreased by 1–2%, but usage of renewables has increased by 1% for hydro and 2% for other renewable sources. Unfortunately, within last years, electricity generation with nuclear power has decreased from 14% before the Fukushima Nuclear Power Plant (NPP) severe accident in March 2011 to about 10%. Therefore, it is important to evaluate current status of nuclear-power industry and to make projections on near (5–10 yr) and far away (10–25 yr and beyond) future trends.
Statistics on Electricity Generation in the World and Selected Countries
This paper is a logical continuation of our previous publications on this topic [1–4]. It is well known that electricity generation and consumption are the key factors for advances in industry, agriculture, technology, and standard of living (see Figs. 1–4 and Tables 1 and 21 (in the Appendix)). Also, strong power industry with diverse energy sources is very important for a country's independence. In general, electricity (see Fig. 3) can be mainly generated from: (1) nonrenewable energy sources such as coal, natural gas, oil, and nuclear and (2) renewable energy sources such as hydro, biomass, wind, geothermal, solar, and marine power.
Today, the main sources for global electrical-energy generation (see Fig. 3(a)) are: (1) thermal power—primarily using coal (38.3%) and secondarily using natural gas (23.1%); (2) “large” hydro-electric plants (16.6%); and (3) nuclear power (10.4%). The last 11.6% of the electrical energy is generated using oil (3.7%), and the remainder (7.9%)—from biomass, geothermal, and intermittent wind, solar, and marine energy. Main sources for electrical-energy generation in selected countries are also shown in Figs. 3(b)–(l) and 4.
World usage of coal, gas, nuclear, and oil has decreased by 1–2%. Usage of renewables has increased by 1% for hydro and 2% for other renewable sources (Fig. 3(a)). However, these changes are not so significant within a number of years.
China has significantly decreased usage of coal for electricity generation from 80% to 65%; and increased usage of hydro power from 15% to 20%, gas from 1% to 3%, nuclear from 2% to 4%, wind from 0% to 4%, and solar from 0% to 1%, which is a very good trend, i.e., decreasing usage of “dirty” coal for electricity generation (Fig. 3(b)).
The U.S. have decreased usage of coal from 39% to 30%; increased usage of gas from 28% to 34%; nuclear, hydro power, and other renewables are approximately on the same level, i.e., 20%; 7%, and 7%, respectively, which is also a good trend (Fig. 3(d)).
Russia has increased usage of gas for electricity generation from 49% to 59%, nuclear from 17% to 19%, and hydro power from 16% to 17% (Fig. 3(g)). Due to these increases, the usage of coal has substantially decreased from 16% to less than 5%.
Germany has visibly decreased usage of coal for electricity generation from 47% to 37%; however, at the same time, the usage of nuclear power was also decreased from 16% to 12% (Fig. 3(e)). This drop in electricity generation was mainly compensated with wind power, which was increased from 8% to 16% (onshore wind farms—13.3% and off-shore—2.8%), gas from 11% to 13%, and solar up to 4% increase.
The United Kingdom has significantly decreased their usage of coal for electricity generation from 17 to 3% within 2015–2017 (Fig. 3(f); also, more detailed comparison, based on data for Q3 per each year, is shown in Figs. 4(a)–4(c)). The usage of coal was substituted mainly with gas, and, partially, with nuclear and renewables. However, in January 2017 quite unusual events have happened, which affected significantly the electricity generation from various sources (Fig. 4(d)). At that time, the UK grid faced a “perfect storm,” which co-inside with a temporary shutdown of a number of NPPs in France, nuclear trips in the UK, and a broken interconnector with France. On the top of that, on Jan. 16, 2017, wind diminished for the whole week. These special and unexpected conditions could definitely lead to a complete blackout. However, gas- and coal-fired power plants have saved the grid (usage of gas for electricity generation has increased by ∼11% and of coal—by ∼15%).
France has not significantly changed their usage of various sources for electricity generation (Fig. 3(l)) over the same period.
Therefore, considering fast changes in climate, possible catastrophic events such as powerful hurricanes, melting ice-caps in mountains, and changes in solar activity, countries should not rely on unreliable renewable sources such as hydro, wind, solar, and marine unless there is a significant backup with reliable energy source(s) independent of Mother Nature (in the case of UK there were thermal power plants and NPPs).
Just for comparison purposes, Table 2 lists 20 largest power plants of the world by installed capacity, and Table 3 lists largest operating power plants of the world by energy source, based on installed capacity.
Overall (gross) or net efficiency (see Table 4): Gross efficiency of a unit during a given period of time is the ratio of the gross electrical energy generated by a unit to the energy consumed during the same period by the same unit. The difference between gross and net efficiencies is an internal need for electrical energy of a power plant, which might be not so small (5% or even more).
Capacity factor of a plant: Net capacity factor of a power plant is the ratio of the actual output of a power plant over a period of time (usually, during a year) and its potential output, if it had operated at a full nameplate capacity the entire time. To calculate the capacity factor, the total amount of energy a plant produced during a period of time should be divided by the amount of energy the plant would have produced at the full capacity. Capacity factors vary significantly depending on the type of a plant (see Table 5). Average capacity factors of the largest power plants in the world are listed in Table 2.
How various energy sources generate electricity in a grid can be illustrated based on the Province of Ontario (Canada) system. Currently, the Province of Ontario (Canada) has completely eliminated coal-fired power plants from its electrical grid. Some of them were closed, others—converted to natural gas. Figure 6(a) shows installed capacity, and Fig. 6(b) shows electricity generation by energy source in the Province of Ontario (Canada) in 2015. Analysis of Fig. 6(a) shows that in Ontario major installed capacities in 2015 were nuclear (38%), gas (29%), hydro (25%), and renewables (mainly wind) (8%). However, electricity (see Fig. 6(b)) was mainly generated by nuclear (60%), hydro (24%), natural gas (8.7%), and renewables (mainly wind) (4.9%).
As a result, Ontario has committed to a massive $25B refurbishment and multiyear life extension of its existing NPPs, on the grounds that “There are currently no alternative generation portfolios that could provide the same supply of low emissions baseload electricity generation at a comparable price to the Nuclear Refurbishment Plan.” (Ontario Financial Accountability Office, “Nuclear Refurbishment Report,” Nov. 21, 2017 ).
Figure 7 shows power generated (a) and capacity factors (b) of various energy sources in Ontario (Canada) electrical grid in winter (Feb. 11, 2015), in spring (Apr. 16, 2015), and in summer (June 17, 2015). Analysis of the data in Fig. 7 shows that nuclear, hydro, gas, wind, biofuel, and solar are the major sources for electricity generation. However, in winter, solar might not be visible (see Figs. 7(a1) and 7(b1)). Somewhere in spring, solar became visible in a grid (see Figs. 7(a2) and 7(b2)). Therefore, a detailed analysis of the Ontario grid operation is provided below for a summer day (see Figs. 7(a3) and 7(b3)).
Electricity that day from midnight till 3 o'clock in the morning was mainly generated with nuclear, hydro, gas, wind, and biofuel. After 3 o'clock, biofuel power plants have increased slightly electricity generation followed by hydro and gas-fired power plants due to increased consumption of electricity in the province. Also, at the same time, wind power plants have also slightly increased electricity generation by the Mother Nature. However, after 7 o'clock wind power started to fluctuate and, eventually, decreased significantly. After 6 o'clock in the morning, solar power plants started to generate electricity.
During a day, hydro, gas-fired, and biofuel power plants had variable electricity generation to compensate changes in consumption of electrical energy and variations in generating electricity from wind and solar power plants. After 9 o'clock in the evening, energy consumption started to drop in the province, and at the same time, wind power increased. Therefore, gas-fired, hydro, and biofuel power plants decreased energy generation accordingly.
It should be noted that NPPs operated at about 100% of installed capacity providing reliable basic power to the grid. This example shows clearly that any grid that includes NPPs and/or renewable-energy sources must also include “fast-response” power plants such as gas-fired, coal-fired and/or large hydropower plants to compensate changes in consumption of electrical energy per day and variations in electricity supply by wind and/or solar power plants.
Usually, NPPs operate continuously on the maximum load, because of a high capital costs and low operating costs. The relative cost of electrical energy generated by any system is not only dependent on building capital costs and operating expenses, but also dependent on the capacity factor. The higher the capacity factor—the better, as generating costs fall proportionally. However, some renewable-energy sources with exception of large hydro-electric power plants can have significantly lower capacity factors compared to those of thermal- and nuclear-power plants (see Table 5).
Also, it should be noted here that countries having a large percentage of variable power sources such as wind and solar, run the risk of an electrical-grid collapse due to unpredicted power instabilities (see the abovementioned example for UK (Fig. 4)). Moreover, the following detrimental factors are usually not considered during estimation of variable power-sources costs: (1) costs of fast-response power plants with service crews on site 24/7 as a back-up power; and (2) faster amortization/wear of equipment of fast-response plants.
The major driving force for all advances in thermal power plants is directed towards increasing thermal efficiency (see Table 4) in order to reduce operating fuel costs and minimize specific emissions, and by that parameter thermal power plants have the highest thermal efficiencies in the power industry: up to 62% for combined-cycle power plants and up to 55% for supercritical-pressure coal-fired power plants.
Despite all advances in thermal power-plants design and operation worldwide, they are still considered as environmentally “unfriendly” due to significant carbon-dioxide emissions (for example, the largest in the world 5780-MWel Taichung coal-fired power plant (Taiwan) is the world's largest emitter of carbon dioxide with over 40 × 106 ton per year) [1,19]) and air pollution as a result of the combustion process. In addition, coal-fired power-plants produce significant amounts of slag and ash, and other greenhouse gases such as SO2, which contributes to acid rains. Comparison of various electricity-generating power plants based on carbon footprint is shown in Fig. 8, deaths per terawatt for various energy sources—in Fig. 9, and per cent of various wastes in total amount—in Table 6. Therefore, nuclear power looks quite attractive based on the abovementioned comparisons.
Modern Nuclear-Power Reactors and Nuclear Power Plants
Nuclear power is often considered to be a nonrenewable-energy source as the fossil fuels, such as coal and gas. However, nuclear resources can be used for significantly longer time than some fossil fuels, and in some cases almost indefinitely, if recycling of unused or spent uranium fuel, thoria-fuel resources, and fast-neutron-spectrum reactors are used. The major advantages of nuclear power  are:
concentrated and reliable source of almost infinite energy, which is independent of weather conditions (however, it should be noted that in summer of 2018, which was very hot on a record due to fast climate changes, some reactors/NPPs were forced to decrease power loads or even were shut down for some time, because of lower levels of water in rivers, etc., and/or of relatively high water temperatures including not only in-land water resources, but, also, sea/ocean waters);
high capacity factors are achievable, often in excess of 90% with long operating cycles, making units suitable for continuous base-load operation (Table 5);
relatively small amount of fuel required compared to that of fossil-fuel thermal power plants (see Table 7); and
NPPs can supply relatively cheap electricity for recharging of electrical vehicles during night hours as they usually operate on full load (capacity) 24/7 (see Fig. 7).
As a result, nuclear power is considered as the most viable source for electricity generation within next 50–100 yr. However, nuclear power must operate and compete in energy markets based on relative costs and strategic advantages of the available fuels and energy types.
Current statistics of all world nuclear-power reactors connected to electrical grids are listed in Tables 8–12, and shown in Figs. 12–15. Analysis of the current statistical data on nuclear-power reactors shows that, currently, 31 countries in the world have operating nuclear-power reactors (within these countries: 18 plan to build new reactors, and 13 do not plan to build new reactors) and 5 countries without nuclear-power reactors (Bangladesh, Belarus', Egypt, Turkey, and UAE) are working toward introducing nuclear energy on their soils (see Table 10).
The largest group of nuclear-power reactors by type is pressurized water reactors (PWRs) (301 from 452 reactors or 67% of the total number), and quite significant number of PWRs are planned to be built (about 77) (for details, see Table 8). The second largest group of reactors is boiling water reactors (BWRs)/advanced BWRs (ABWRs) (72 reactors or 16% of the total number). The third group is PHWRs (48 reactors or 11% of the total number). Considering the number of forthcoming reactors, the number of BWRs/ABWRs and PHWRs will possibly decrease within next 20–25 yr. Furthermore, within next 10–15 yr or so, all advanced gas-cooled reactors (AGRs) (carbon-dioxide-cooled) and light-water-cooled graphite-moderated reactors (LGRs) will be shut down forever. However, instead of carbon-dioxide-cooled AGRs helium-cooled reactors will be built and put into operation.
Analysis of the data in Tables 9 and 10 shows that real nuclear “renaissance” is in China (32 reactors built and put into operation within past 8 yr!), in Russia (addition of 5 reactors), and in South Korea (addition of 3 reactors). Meanwhile, the most significant drop in a number of reactors is in Japan (12 reactors were shut down) (only about 9 reactors out of 42 are currently in operation), in Germany (10 reactors), in U.S. (6 reactors), in UK (4 reactors), and in Canada (3 reactors). In addition, Germany and Canada have no plans to build new reactors (for details on other countries, see Tables 9 and 10).
Table 11 lists current activities in various countries worldwide on new nuclear-power-reactors build. Analysis of the data in Table 11 clearly shows that China and Russia are the front runners in new nuclear builds in their countries and abroad. And it is not a big surprise, because both governments provide a significant and long-term support with various funds for nuclear-power R&D and their nuclear vendors, especially, to build NPPs abroad plus credits and other incentives for foreign countries, which would like to introduce nuclear power on their soils.
Last several years and, especially, year of 2018, were very important for the nuclear-power industry of the world. As such, Russia put into operation a number of Generation III+ VVERs (PWRs) (for technical parameters, see Tables 13 and 14) and the SFR-BN-800 reactor in 2016 (for technical parameters, see Table 15 and Fig. 11) and continue to lead the SFR technologies in the world.
China put into operation many reactors/NPPs including the largest in the world Generation III+ PWR—EPR (Areva design) with amazing installed capacity of 1660 MWel (see Table 12 for a list of largest operating nuclear-power reactors in the world with installed capacities from 1400 MWel and above, and Table 16 for basic parameters of EPR). In addition, several AP-1000 reactors (Westinghouse design), also, a Generation III+ design, were put into operation in China first time in the world (for major differences between Generation III and Generation III+ reactors, see a comparison of basic parameters of ABWR and BWR by Hitachi-GE Nuclear Energy (Table 17)). In general, Generation III+ reactors/NPPs have installed capacities from 1000+ to 1660 MWel, enhanced safety, and can reach slightly higher thermal efficiencies up to 36–37% (38%) compared to those of generation III reactors/NPPs. In addition, Table 18 lists basic data on APR-1400 (Doosan design)—Generation III+ PWR from South Korea, which operates there, and seven more will be put into operation soon: three in South Korea and four in UAE (Table 10).
Year of 2019 and following years will be also very important ones, because a unique GCR—a helium-cooled reactor—HTR-PM should be put into operation China. Also, a number of Generation III+ reactors around the world are expected to be put into operation as well, plus, at least one, or a number of SFR(s) can be added to the fleet of nuclear-power reactors (see Table 10 or the latest March issue of Nuclear News ). In addition, a number of nonnuclear-energy countries will have operating nuclear-power reactors (Table 10).
Figure 12 shows impact of the major NPPs accidents within the last 50 yr on new builds. Analysis of the data in this figure shows that we might face a very significant drop (up to three times) in a number of operating nuclear-power reactors somewhere between 2030 and 2040 (see Fig. 16); if we assume that current operating term of reactors is on average 45 yr, and the rate of building and putting into operation new reactors is ∼21 reactors per 5 yr. Even with higher rates of new nuclear-capacities additions, we will have a tangible decrease in a number of operating reactors. If this forecast(s) is correct, the nuclear-power industry will face very difficult times ahead. Conservative projections for selected countries in terms of a number of reactors, which might be shut down within future years, are shown in Figs. 17 and 18.
It should be once more emphasized that, in general, current problems in the world nuclear-power industry are: significant delays in putting into operation new, mainly, Generation III+ reactors, indecision of governments in terms of support of nuclear-based electricity generation; and radioactive-waste management and safe storage.
Currently, operating NPPs with water-cooled nuclear reactors, which are the largest group of all reactors' types (∼96% of 452 nuclear-power reactors), have lower thermal efficiencies (32–36% (38%)) compared to those NPPs with liquid metal-cooled (SFRs) (up to 40%) and gas-cooled reactors (AGRs) (up to 42%), and way below of those of modern advanced thermal power plants (see Table 4). Therefore, to be competitive on energy markets, it is necessary to make this type of NPPs more efficient.
The major problem with low thermal efficiency of NPPs with water-cooled reactors is that at the turbine inlet we have only saturated steam of low parameters (maximum steam parameters as of today are: Psat ≈ 7 MPa and Tsat = 285.8 °C). Areva has planned to have the pressure of 7.8 MPa (Tsat = 293.7 °C) at the turbine inlet of the largest in the world by the installed capacity EPR (1660 MWel), which can push the gross thermal efficiency of a NPP up to 37–38%.
Therefore, we need to have bright future for these the most “popular” NPPs. The conventional way, which the thermal-power industry has passed at the end of 50 s, was increasing a pressure at the steam-turbine inlet from a subcritical to supercritical one and having steam superheat up to 625 °C. This approach allowed to move from about 43% gross thermal efficiency to about 55% for supercritical-pressure coal-fired power plants (see Table 4). Due to this one of the six concepts of the Generation IV nuclear-power reactors is a supercritical water-cooled reactor [1,28,35,36]. Also, there is an interim approach, which is only applicable to pressure-channel reactors—to introduce a nuclear steam superheat inside a reactor, which was tested in 1960s and 1970s in USA, Russia, and some other countries .
Small Modular Reactors
Small modular reactors (SMRs) are today's a very “hot” topic in nuclear engineering worldwide [1,38]. According to the IAEA ARIS (Advanced Reactors Information System) data, there are about 55 SMRs designs/concepts, which can be classified as: (1) water-cooled SMRs (land based)—19; (2) water-cooled SMRs (marine based)—6; (3) high-temperature gas-cooled SMRs—10; (4) molten-salt SMRs—9; (5) fast-neutron-spectrum SMRs—10; and (6) other SMRs—1. From all these 55 SMRs only two KLT-40S reactors have been constructed, installed on a barge, and should be put into operation in 2019; CAREM (Central Argentina de Elementos Modulares) SMR (PWR-type; 25 (32) MWel; CNEA (Comisión Nacional de Energía Atómica), Argentina) is under construction now, and FUJI (200 MWel, MSR International Thorium Molten-Salt Forum (ITMSF), Japan) is possibly within an experimental phase.
In general, as of today, a number of small nuclear-power reactors by installed capacity (10–300 MWel) operate around the world (see Table 19). Moreover, some of them operate successfully for about 50 yr! However, they cannot be named as SMRs. Also, France, Russia, UK, USA, and other countries have great experience in successful development, manufacturing, and operation of submarines, icebreakers, and ships propulsion reactors. Therefore, many modern designs/concepts of SMRs are based on these achievements. (Also, it should be mentioned that a number of SMRs concepts are based on the Generation IV nuclear-power-reactors concepts .)
As such, Russia has adjusted their proven marine reactor—KLT-40S for operation as an SMR for electricity generation and heat supply (also, a desalination of water is possible). Figure 19 shows a schematic of KLT-40S reactor and its systems; Fig. 20—photo of reactor KLT-40S with four steam generators and reactor-coolant circulation pumps; Fig. 21—KLT-40S reactor-core cross section; Fig. 22—photo of the floating nuclear thermal-power plant (FNThPP) with two KLT-40S reactors; and Table 20—main parameters of KLT-40S.
The barge with two KLT-40S SMRs will be towed to and then put into operation at Pevek, Russia's northernmost city in 2019, where it will gradually replace the Bilibino NPP (see Table 19) and the Chaunskaya combined heat and power plant, which are being retired. Commercial start of these two SMRs is planned for 2019 . Currently, the FNThPP is temporary located in the port of Murmansk (Russia), where, on Nov. 4, 2018, first KLT-40S has reached the minimum controlled power level.
It is very difficult to believe that SMRs somewhere in the future will replace nuclear-power reactors, but they have their own “niche,” in particularly, electricity and heat supplies (also, desalination of water possible) for remote settlements, military bases, mines, etc. around the world.
In general, SMR-based NPPs will have lower thermal efficiencies compared to those of similar type regular NPPs; higher level of fuel enrichment compared to water-cooled nuclear-power reactors to be able to operate for longer periods between refuelings, etc.
Economic and Competitiveness Issues for Nuclear Power Plants
Key to successful deployment of any such new or next generation nuclear concepts or designs is the ability to compete against available energy alternates, especially, in local or national power markets.
Market share is fundamentally determined by price advantage relative to competitors, and conversely, the driving forces for innovation and cost reduction are those of the competitive marketplace . Traditional overall electricity demand, market economics, comparative plant costing, and regulations are covered in great detail elsewhere [41–44]. To determine the optimization of cost and size in competitive power markets, the competition for power and energy generation is low capital cost of natural-gas combined-cycle plants with multiple module layouts; and large advanced supercritical-pressure-coal units, both with cycle efficiencies reaching near 60% , which are cheaper (on an overnight capital, levelized unit energy cost (LUEC) or cost of energy (COE) basis). The reactor island is a small fraction of the total plant or project costs, so it is evident that technology choice is not the key, as the market has no “favorites.” The real issue is fully optimizing the overall cost and efficiency of the design and performance of any “Technology X” units to meet power- and financial-market requirements, not choosing or developing something that is superficially attractive, but too expensive.
Adverse external key-market developments and challenges to increased nuclear deployment include: (1) the emergence of even lower cost “fracking” technology for natural-gas production; (2) closure and insolvency threats for some U.S. NPPs; (3) the Fukushima NPP accident; (4) the effective bankruptcy and financial/corporate reorganization of three large nuclear-plant manufactures; (5) new build activity dominated by state-supported manufacturers with financing, and/or political guarantees; (6) the utilization of mandatory portfolios, feed-in tariffs and reverse metering preferentially for wind and solar generation. The requirements and internal challenges for any new nuclear concepts/design/technology are, and always will be [1,2,45]:
safer than previous “generations”;
low financial risk exposure and capital cost;
ease and speed of build;
simple to operate and secure;
assured fuel supply and sustainability;
providing social value and acceptance; and, of course;
be competitive with respect to lowest costs generation.
The standard models of discounted cash flow provide generating costs as a function of capital and operating expenses, discount or loan rate, construction time, and other “fixed” and variable costs to determine income and the return on investment [2,41–44]. Having set the sales potential, target markets, and performance goals, the approach must combine the plant and market economics in three simple, but interwoven steps for any given conceptual technology:
Step 1: Assess the optimum capital, operating, and generating costs as a function of plant output size to determine the system design targets and technical requirements.
Step 2: Minimize risk in the cash flow scenario assuming given build constraints and options for single and multiple units to establish investment needs and suitable power purchase agreements or contracts.
Step 3: Determine the build profile of unit/plant number and output matching the power market and customer generating needs, establishing the optimum niche and market specific share; then iterate back through the steps 1, 2, and 3 as needed to meet the goals, if necessary changing or even adopting a different technology.
This feedback process must be completed before committing to preliminary design work and reevaluated periodically during the overall design and engineering process. This systematic method provides a coherent business model for both supplier and customer and is also useful as a rapid audit and estimating tool, and to weed out uncompetitive options (details can be found in Ref. ).
Capital- and operating-cost reduction is the obvious first target, while licensing, siting, fuel, and decommissioning costs are difficult to reduce substantially. So the objectives are to simplify and “modularize” the design, reducing capital and operating costs, and shortening construction times. Very often, customers require a reference plant for cost, safety, and design comparison purposes. Hence the emphasis for any bid on reducing, optimizing and managing fixed capital and operation and maintenance costs, and on multiple builds based on a “standardized” design for which the usual economic methods exist . The fundamental problem is that a decrease in plant output increases the LUEC/LCOE, because many of the balance of plant and other variable and fixed costs (of site, safety, infrastructure, engineering, decommissioning, and staffing) do not decrease proportionately, so ultimately become dominant as output shrinks.
However, recent build experience in Europe, USA, and China shows that some large plants often require over the nominal 60-months completion time, or experience significant delays in construction or schedule times. Long schedules and delays are the major factor that must be avoided, incurring approximately a linear LUEC/LCOE increase with project timescale. For a given interest rate, it is necessary to optimize the build scenario for the potential of sequentially adding some number of multiple units that can be of any selected size and, hence, cost. This implies the “order book” approach, which is necessary to initiate and commit the program beforehand, as practiced in the aircraft manufacturing industry. Otherwise the first-of-a-kind engineering, design, licensing, and setup costs all have to be absorbed by the first few units. In addition, the cost of multiple units must be reduced by the “learning effect” of an experienced production line for the Nth-of-a-kind units [46,47].
To “fill the order book” is design and market specific, but the maximum ∼50% reduction possible from mass production matches that required to offset the cost of smaller plants/units [48,49]. This result is theoretically based and describes actual data worldwide (Fig. 23).
The net-cash flow for a multiple-unit build program is calculated as the difference between outgoing operating and debt expenses and the income from power sales, and will be investor and market specific.
Investment in module “factories” is expensive, requires large up-front commitment (for say, options for 100 standardized units per the aircraft industry “order book” approach), and the downside risks must be carefully managed, since, that cost must also be subtracted, or amortized (realized) by or from the sale of many units. Hence, it is self-evident that although small and units cost more for their power and energy, only with multiple builds do they carry significantly less financial risk and for much shorter exposure times.
Although every market is geographically different, they share the same goal of attaining a dynamic balance between supply and demand [41–43]. This balance has to occur both during the daily short-term swings in demand, bringing plants “on line”; and, also, in the longer term for meeting future demand projections and units being added and/or retired. The overall approach to meeting demand is obviously “cheapest first,” or a merit order [41,43,50], except, when there is a mandatory feed-in-tariff or reverse metering obligation, or no choice. For any technology, the fraction of the total market power demand that is available for or at a specific cost advantage is proportional to the incremental area under the merit order curve. The result is that the fractional market share is exponentially (and not linearly) dependent on the LUEC/LCOE cost advantage .
Obviously, the fractional market share is partly determined by price advantage for a whole range of alternate fuels, at both the national and local levels. For example, new nuclear builds must compete with: coal plants in China, Virginia, and Alberta; hydropower in Washington and Quebec; natural-gas turbines and LNG in USA, Asia, and Europe; state-supported nuclear from and in Russia, China, France, and Korea; with renewable portfolios and FITs in Europe and Canada; and with diesel fuels in remote locations. Detailed energy projections out to 2040 show modest nuclear growth, and state :” Natural gas demand rises the most, largely to help meet the increasing needs for electricity and support increasing industrial demand.”
No clear market or price advantage for current SMR concepts has been shown in recent comparative studies that have been independently published [50,52], emphasizing the need for enhanced competitiveness. The OECD (Organization for Economic Co-operation and Development) estimate is that the global market share by 2035 could be the “high case” 9%, or 3% for the “low case” for some hypothetical/generic SMR “Technology X” . The middle of this range is the worldwide 6% nuclear share or market entry already historically attained, when there is essentially little or no cost advantage , so is within the uncertainties due to local market vagaries and variations.
Several key challenges still remain today and in the future, some of which are well known low capital cost and high efficiency of modern natural gas and supercritical-pressure coal-fired power plants, including modular gas turbines and mobile power concepts, are likely to dominate many markets for the next 20 years. This timeframe is sufficient for competitive nonconventional and innovative nuclear-technology developments to emerge that challenge many of the paradigms of the past .
It is well known that electrical-power generation is the key factor for advances in industry, agriculture, technology, and level of living. Also, strong power industry with diverse energy sources is very important for a country's independence.
Major sources for electrical-energy generation in the world today are: (1) thermal— primary coal (38.3%) and secondary natural gas (23.1%); (2) “large” hydro (16.6%); and (3) nuclear (10.4%). The remaining 11.6% of the electrical energy is generated using oil (3.7%) and renewable sources (biomass, wind, geothermal, and solar energy) (7.9%) in selected countries.
Other energy sources such as renewable wind-, solar-, marine-power have a visible impact just in some countries, especially, where there are government incentives with electricity prices guaranteed by legislation and power-purchase contracts. However, these apparently attractive renewable-energy sources (wind, solar, tidal, etc.) are not reliable as full-time energy sources for industrial-power generation. To overcome this problem, an electrical grid must also include “fast-response” power plants such as gas- (coal-) fired and/or large hydro-power plants.
In general, the major driving force for all advances in thermal and nuclear power plants is thermal efficiency and generating costs. Ranges of gross thermal efficiencies of modern power plants are as the following: (1) combined-cycle thermal power plants—up to 62%; (2) supercritical-pressure coal-fired thermal power plants—up to 55%; (3) carbon-dioxide-cooled reactor NPPs—up to 42%; (4) SFR NPP—up to 40%; (5) subcritical-pressure coal-fired thermal power plants—up to 43%; and (6) modern water-cooled-reactor NPPs—30–36% (38%).
Combined-cycle thermal power plants with natural-gas fuel are considered as relatively clean fossil-fuel-fired plants compared to coal and oil power plants, and are dominating new capacity additions, because of their relatively lower carbon-dioxide production and lower costs using natural gas, LNG, or natural gas derived from “fracking” processes.
Nuclear power is, in general, a nonrenewable source unless fuel recycling, thoria fuel, and/or fast-neutron-spectrum reactors are adopted, which means that nuclear resources can be used significantly longer than some fossil fuels. Currently, this source of energy is considered as the most viable one for base-load electrical generation for the next 50–100 yr.
However, all current generations-II and -III and oncoming generation-III+ NPPs, especially, those equipped with water-cooled reactors, are not competitive with modern thermal power plants in terms of thermal efficiency (30–36% (38%) for current NPPs with water-cooled reactors and 55–62% for supercritical-pressure coal-fired and combined-cycle power plants, respectively).
Enhancements are needed beyond the current building plans for NPPs. These new designs must compete in the world markets, and if possible, without government subsidies or power-price guarantees. New generation NPPs must have thermal efficiencies close to those of modern thermal power plants, i.e., within a range of at least 40–50%, and incorporate improved safety measures and designs.
The major advantages of nuclear power are well known, including cheap reliable base-load power, high capacity factor, low carbon-dioxide emissions, and minor environmental impact. However, these factors are offset today by a competitive disadvantage with natural gas and the occurrence of three significant nuclear accidents (Fukushima, Chernobyl, and Three Mile Island NPPs). The latter have caused significant social disruption together with high capital costs.
Currently, 31 countries have operating nuclear-power reactors, and 5 countries plan to build nuclear-power reactors. In addition, 30 countries are considering, planning or starting nuclear-power programs, and about 20 countries have expressed their interest in nuclear power. However, 13 countries with NPPs do not plan to build new nuclear-power reactors. Moreover, such countries as Taiwan, Switzerland, and some others might not proceed with new builds.
In October 2018, 451 nuclear-power reactors operated around the world. This number includes 300 PWRS, 72 BWRs, 48 PHWRs, 14 AGRs, 15 LGRs, and 2 LMFBRs. Considering the number of forthcoming reactors, the number of BWRs/ABWRs and PHWRs will possibly decrease within next 20–25 years. Furthermore, within next 10–15 years or so, all AGRs (carbon-dioxide-cooled) and LGRs will be shut down forever. However, instead of carbon-dioxide-cooled AGRs helium-cooled reactors will be built and put into operation.
In 2018, several very important milestones have been achieved—first EPR and AP-1000 NPPs have been put into operation in China. In 2019, it is expected that China will put into operation first in the world nuclear-power helium-cooled pebble-bed reactor. Also, in 2016, second SFR-BN-800 was put into operation in Russia.
Analysis of the current statistics on nuclear-power reactors of the world shows that we might face a very significant drop (up to three times) in a number of operating nuclear-power reactors somewhere between 2030–2040; if we assume that current operating term of reactors is on average 45 years, and the rate of building and putting into operation new reactors is ∼21 reactors per 5 years. Even with higher rates of new nuclear-capacities additions, we will have a tangible decrease in a number of operating reactors. If this forecast(s) is correct, the nuclear-power industry will face very difficult times ahead.
SMRs are today's a very “hot” topic in nuclear engineering worldwide [1,37]. According to the IAEA, there are about 55 SMRs designs/concepts proposed in the world. There is a possibility that in 2019, Russia will put into operation first two SMRs-KLT-40S reactors barge-based as a floating NPP for the Northern regions.
In spite of all current advances in nuclear power, NPPs have the following deficiencies: (1) generate radioactive wastes; (2) have relatively low thermal efficiencies, especially, NPPs equipped with water-cooled reactors (up to 1.6 times lower than that for modern advanced thermal power plants; (3) risk of radiation release during severe accidents; and (4) production of nuclear fuel is not an environment-friendly process. Therefore, all these deficiencies should be addressed in next generation—generation IV reactors and NPPs.
- ABWR =
advanced boiling water reactor
- AECL =
Atomic Energy of Canada Limited
- AGR =
advanced gas-cooled reactor
- AP =
Advanced Plant (USA)
- APR =
Advanced Pressurized-Water Reactor (South Korea)
- ARIS =
Advanced Reactors Information System
- ASME =
American Society of Mechanical Engineers
- B =
- BN =
fast sodium (reactor) (in Russian abbreviations)
- BWR =
boiling water reactor
- CANDU =
Canada Deuterium Uranium (reactor)
- CAR =
Central African Republic
- COE =
cost of energy
- Corp. =
- CNNC =
Chian National Nuclear Corporation
- D =
- DAI =
Department of Atomic Energy (India)
- EEC =
- EGP =
Power Heterogeneous Loop Reactor (in Russian abbreviations)
- EPR =
European Pressurized-Water Reactor (France)
- FNThPP =
floating nuclear thermal-power plant
- GCR =
- GE =
General Electric (USA)
- HDI =
human development index
- HTR PM =
high temperature reactor pebble-bed modular (reactor)
- IAEA =
International Atomic Energy Agency
- ID =
- JSME =
Japan Society of Mechanical Engineers
- K =
condensing (in Russian abbreviations)
- L =
- LGR =
light-water-cooled graphite-moderated reactor
- LMFBR =
liquid-metal fast-breeder reactor
- LMR =
- LNG =
liquefied natural gas
- Ltd =
- LUEC =
levelized unit energy cost
- MHI =
Mitsubishi Heavy Industries (Japan)
- MSK =
- MTM =
Ministry of Heavy Machine Building (in Russian abbreviations) (Russia)
- NASA =
National Aeronautics and Space Administration (USA)
- NERS =
(ASME Journal of) Nuclear Engineering and Radiation Science
- NOAA =
National Oceanic and Atmospheric Administration (USA)
- NPP =
nuclear power plant
- OECD =
Organization for Economic Co-operation and Development
- PHWR =
pressurized heavy-water reactor
- PV =
- PWR =
pressurized water reactor
- Q =
- RBMK =
Reactor of Large Capacity Channel Type (in Russian abbreviations) (Russia)
- R&D =
research and development
- RPV =
reactor pressure vessel
- SFR =
sodium fast reactor
- SG =
- SMR =
small modular reactor, also, small and medium size reactor
- SSE =
safe shutdown earthquake
- SVBR =
lead-bismuth fast reactor (in Russian abbreviations)
- FIT =
- ТГВ =
turbine generator with hydrogen (/water) cooling (in Russian abbreviations)
- UAE =
United Arab Emirates
- UK =
- UOIT =
University of Ontario Institute of Technology
- VVER =
water power reactor (in Russian abbreviations) (Russia)
- W =
- WNA =
World Nuclear Association