Slogan of nuclear power training

(Report producer/analyst: Industrial Securities Cai Chunchi Shi Yisu)

1. 1 Overview of nuclear power principle: fission chain reaction generates energy and steam drives steam turbines to generate electricity.

Nuclear energy releases energy from the nucleus through nuclear fission, nuclear fusion and nuclear decay, in which nuclear fission chain reaction is the principle of nuclear power generation.

Nuclear power generation mainly uses the characteristics that the nuclei of larger atoms (such as uranium, thorium and plutonium) will split into multiple smaller nuclei after absorbing a neutron, and release two or three neutrons and huge energy at the same time. The released neutrons and energy will cause nuclear fission of other atoms, so that the process of releasing energy will continue. This series of reactions is called nuclear fission chain reaction. Nuclear fission chain reaction is the energy source of nuclear power generation.

Nuclear power plant makes the energy generated by nuclear fission chain reaction complete the transformation of nuclear energy-thermal energy-mechanical energy-electrical energy, thus achieving the purpose of generating electricity.

Nuclear power plants can be roughly divided into nuclear island part (NI) and conventional island part (CI):

Nuclear island part: The nuclear island part includes reactor device and primary system, which is mainly used for nuclear fission reaction and steam generation.

The function of nuclear island reactor is to produce nuclear fission and convert the energy released during fission into heat energy of water; After absorbing heat energy, water enters the U-shaped tube of the steam generator along the pipeline in the form of high temperature and high pressure, and transfers heat to the water outside the U-shaped tube, so that the water outside becomes saturated steam; The cooled water will be pumped back to the reactor by the main pump for reheating, forming a closed loop of heat absorption and heat release with water as the carrier, which is the so-called primary loop, also known as "steam supply system".

Conventional island part: The conventional island part includes a steam turbine generator system and a secondary loop system, and its main function is to use steam to drive a steam turbine to generate electricity.

The steam generated by partial heat transfer in the nuclear island will enter the steam turbine in the conventional island, and the thermal energy of the steam will be converted into mechanical energy of the steam turbine, and then the mechanical energy will be converted into electrical energy through the rotor connected to the generator, thus completing the power generation process.

At the same time, the steam (exhaust steam) after doing work is discharged into the condenser, cooled by circulating cooling water, condensed into water, then sent to the heater for preheating by the condensate pump, and finally sent to the steam generator by the feed pump, forming another closed circulation system with water as the carrier, which is called "secondary loop".

In principle, the secondary loop system is basically the same as the steam power loop of conventional thermal power plants.

1.2 nuclear power business model: asset-heavy model+cash cow in operation period.

The business model of nuclear power presents the characteristics of "asset-oriented model+cash cow in operation period";

Construction period: the construction period is long and the investment is large.

Due to extensive delay, the actual construction period of nuclear power plant is about 5- 10 years. The design cycle of nuclear power plants is usually five years. However, due to lack of construction experience, design changes, time-consuming testing and other reasons, the delay of the first reactor of nuclear power units is widespread in China, which leads to the increase of interest expenses and power generation costs during construction.

Mass production is conducive to shortening the construction period and reducing the cost of nuclear power units. After batch construction, the construction period of the same model series of m 3 10/ CPR can be gradually stabilized at about 5 years.

The investment per kilowatt of the third generation nuclear power in China is about10.5 million yuan.

On the basis of AP 1000, the construction cost of the third generation nuclear power technology CAP 1000 is 14000 yuan /kW, and the construction cost of Hualong No.1, which belongs to the third generation nuclear power technology, is 17390 yuan /kW. Based on this calculation, the corresponding investment of a million kilowatt nuclear power unit is about 654.38+0.5 billion yuan, showing the characteristics of large investment.

Operation period: a stable cash cow

Similar to the hydropower industry, the nuclear power industry has the characteristics of stable cash cow during the operation period.

The nuclear power plant follows the split formula of operating income = electricity price * on-grid power = electricity price * installed capacity * utilization hours *( 1- auxiliary power consumption rate), so the operating income is highly certain. At the same time, due to the high investment in the early stage of the project, the depreciation cost of fixed assets is high (accounting for 30-40% of the main business cost), and the non-cash cost (depreciation) accounts for a relatively high proportion in the cost of nuclear power plants.

Therefore, once the nuclear power plant enters the operation period, it will show the characteristics of obtaining stable and abundant operating net cash flow.

1.3 low-carbon and high-efficiency base load power supply is of great significance under the goal of "double carbon"

Nuclear power has the characteristics of low carbon and high efficiency, and the proportion of nuclear power in China is obviously lower than the global level.

Compared with other power generation methods, nuclear power has the characteristics of high utilization hours, low power cost, low carbon, stability and high efficiency, and is suitable for development as a high-quality base load power source.

From the perspective of power supply structure, the proportion of nuclear power in China is only 4.80% in 2020, which is not only lower than the 64.53% of France, a big country in nuclear energy utilization, but also significantly lower than the global average of 9.52%. There is still much room for improvement in the proportion of nuclear power in China.

Under the goal of "double carbon", the proportion of non-fossil energy has increased, and the importance of nuclear energy has become prominent.

At the Climate Ambition Summit in June 5438+February, 2020: By 2030, the carbon dioxide emissions per unit of GDP will be reduced by more than 65% compared with 2005, and the proportion of non-fossil energy in primary energy will reach about 25%.

202 1,101On October 24th, the Opinions of the Central Committee of the State Council on Completely, Accurately and Comprehensively Implementing the New Development Concept and Doing a Good Job in Carbon Neutralization at the Peak of Carbon Dioxide Emission proposed to actively develop non-fossil energy, implement renewable energy substitution actions, continuously increase the consumption proportion of non-fossil energy and actively, safely and orderly develop nuclear power.

20211KLOC-0/October 26th, the State Council officially released the Action Plan for CO2 Emission Peak by 2030, which pointed out that "nuclear power should be actively, safely and orderly developed.

Reasonably determine the layout and development sequence of nuclear power plants, develop nuclear power in an orderly manner under the premise of ensuring safety, and maintain a stable pace of construction.

Actively promote advanced reactor demonstration projects such as high-temperature gas-cooled reactors, fast reactors, modular small reactors and offshore floating reactors, and carry out demonstrations on comprehensive utilization of nuclear energy.

Strengthen the standardization and autonomy of nuclear power, speed up key technologies and equipment research, and cultivate high-end nuclear power equipment manufacturing industrial clusters.

Implement the strictest safety standards and the strictest supervision, and continuously improve the ability of nuclear safety supervision. Comparing the changes of energy structure in China in recent 10 years, the proportion of non-fossil energy increased from 8.40% in 20 1 1 to 15.90% in 2020. From the perspective of power supply structure, according to the data of China Electric Power Enterprise Association, the proportion of nuclear power has increased from 1.85% and 438+0 in 2065 to 4.86% in 2026, and the importance of nuclear energy is becoming more and more prominent.

2. 1 nuclear power technology evolution: economy and safety promote the development of nuclear power technology.

Economy and safety are the core goals to promote the development of nuclear power.

The development of nuclear power plants began in 1950s, and the energy crisis triggered by the rising oil price in 1970s promoted the development of nuclear power. At present, most of the more than 400 nuclear power units in commercial operation in the world were built during this period.

In the 1990s, in order to solve the negative impact caused by the serious accidents at Three Mile Island and Chernobyl nuclear power plants, the United States and Europe successively issued "User Requirements for Advanced Light Water Reactors" and "User Requirements for European Light Water Reactors Nuclear Power Plants", and the nuclear power units that meet one of these two documents are called the third generation nuclear power units.

265438+At the beginning of the 20th century, GIF proposed that six reactor types, namely sodium-cooled fast reactor, lead-cooled fast reactor, gas-cooled fast reactor, supercritical water-cooled reactor, ultra-high temperature gas-cooled reactor and molten salt reactor, should be identified as the key research and development targets of the fourth generation nuclear power plant. The fourth generation nuclear power technology has strengthened the requirement of preventing nuclear proliferation. At present, the embryonic form of relevant industrial chains has basically taken shape, and the commercialization process is expected to begin in 2030.

2.2 20 19 nuclear power approval was restarted, and the third generation unit became the main model.

20 16-20 18 China nuclear power has been "zero approval" for three consecutive years, and the development of nuclear power is at a standstill.

20 1 1 year, Fukushima nuclear power plant in Japan was hit by the tsunami caused by the earthquake, and a serious nuclear accident occurred. Countries around the world began to be cautious about the construction of new nuclear power plants, which also slowed down the approval speed of China nuclear power plants.

In 20 15, China approved eight nuclear power units, and then entered a stagnant state from 20 16 to 20 18, and "zero approval" for three consecutive years.

20 19 nuclear power approval was restarted, and the third generation nuclear power unit is becoming the main model.

After 20 18, many third-generation nuclear power units in China were put into commercial operation, and the safety and reliability of the third-generation units were affirmed; In addition, on October 28th, 2065438+2008/KLOC-0, the first reactor of the third generation nuclear power unit "Hualong No.1" independently developed by China and the pressure vessel of the reactor of Fuqing Nuclear Power Unit 5 of China National Nuclear Corporation were successfully hoisted into the reactors, and the construction works were progressing smoothly. Affected by this, China's nuclear power approval work has once again been put on the agenda.

2065438+In July 2009, the National Energy Administration said that the nuclear power projects in Rongcheng, Shandong, Zhangzhou, Fujian and Taipingling, Guangdong were allowed to start, marking the official resumption of nuclear power approval.

In 2020, a total of 4 units of Hainan Changjiang Nuclear Power Phase II Project and Zhejiang Sanao Nuclear Power Phase I Project were approved;

202 1 year Jiangsu Tianwan Nuclear Power Station 7&; Units 3-8 of Liaoning Xudabao Nuclear Power Plant; Unit 4 and Unit 5 of Hainan Changjiang Multi-purpose Modular Small Reactor Science and Technology Demonstration Project were approved, and the approval progress of nuclear power units in China is progressing in an orderly manner.

Judging from the start-up of nuclear power units after 20 19, the third generation nuclear power units represented by "Hualong No.1" and "VVER" have become the main models.

The independent third-generation nuclear power is expected to advance steadily according to the approval rhythm of 6-8 units per year, and the "positive development" policy is gradually being fulfilled. In March, 20021year, the government work report mentioned "actively and orderly developing nuclear power on the premise of ensuring safety", which was the first time that1year used "positive" to express the nuclear power policy.

According to the "Development and Prospect of Nuclear Energy in China (202 1)" issued by China Nuclear Energy Industry Association, it is estimated that the independent third-generation nuclear power in China will be steadily promoted according to the approval rhythm of 6-8 units per year, and 5 units will be approved and started in 20021year, and the policy of active and orderly development is gradually being fulfilled.

3. 1 The rapid development of the fourth generation nuclear power technology is expected to lead the nuclear power industry into a new era.

The fourth generation of nuclear power is expected to lead the nuclear power industry into a new era.

In recent years, with the support of "863", "973", nuclear energy development, major special programs and the international cooperation framework of the fourth generation nuclear energy system, China has successively carried out research and development of five types of reactors, namely, high temperature gas-cooled reactor, sodium-cooled fast reactor, supercritical water-cooled reactor, lead-cooled fast reactor and molten salt reactor, and achieved a series of research results, which are basically synchronized with the international level. Among them, China high-temperature gas-cooled reactor and sodium-cooled fast reactor are in the forefront of the world.

High-temperature gas-cooled reactor uses its high-temperature characteristics to expand the application prospect of nuclear energy in industrial fields such as process heating, hydrogen production by nuclear energy and efficient power generation. Fast reactor is the only key reactor type that can realize fuel proliferation, which will obviously improve the utilization rate of uranium resources and minimize waste by transmutation.

China's R&D is in the forefront of the world in terms of high temperature gas-cooled reactor and sodium-cooled fast reactor.

High temperature gas-cooled reactor 2021February 20th, the world's first Huaneng Shidaowan high temperature gas-cooled reactor was successfully connected to the grid for power generation, and two high temperature gas-cooled reactors are planned to be built in Shandong Haiyang Xin 'an nuclear power project.

As for the sodium-cooled fast reactor, the CNNC Xiapu 600MW demonstration fast reactor project started at the end of 20 17 and is scheduled to be completed and put into operation in 2023.

High temperature gas-cooled reactor: an advanced reactor type with inherent safety and potential economic competitiveness.

Intrinsic safety: that is, in the event of a serious accident, including the loss of all cooling capacity, the nuclear power plant can only rely on the material's own ability to ensure that the reactor radioactivity will not melt and leak a lot.

The specific performance is as follows:

(1) to prevent runaway power growth.

Taking Shidaowan demonstration project in China as an example, it adopts the method of continuous on-line fuel loading and unloading without stopping, forming a flowing pebble bed reactor core; Moreover, the demonstration reactor uses graphite as moderator, and the core structure material does not contain metal, which has high stability, large core heat capacity and low power density.

(2) Waste heat utilization.

High temperature gas-cooled reactor uses helium as primary coolant, which has good thermal conductivity. In the case of failure of the main conduction system, the core residual heat can be led out by natural mechanisms such as heat conduction, and then discharged through the passive residual heat discharge system, and the residual heat is not enough to melt the core.

③ Sealing of radioactive materials.

The demonstration reactor uses all-ceramic coated granular fuel elements and four layers of shielding materials to wrap the fuel core. As long as the ambient temperature does not exceed 1650, the silicon carbide spherical shell can remain intact and lock radioactive fission products. After testing, the normal operating temperature of the demonstration reactor is as high as 1620, and the radioactivity has reached the best level in the world.

Potential economic competitiveness: Take Shidaowan demonstration project as an example, it can be achieved through ① highly independent equipment (the localization rate of demonstration project is 93.4%) and ② "all-in-one" (under the condition of keeping the main system unchanged, the two modules are combined into one, that is, the nuclear island is driven by two pebble bed reactor modules and two steam generators, and generated by a steam turbine.

This modular construction shortens the construction period, greatly reduces the construction quantity and improves the economy) to control the cost.

At the same time, if we compare the construction cost, although the powder metallurgy cost of the reactor body (mainly PRV and internals) is much higher than that of the PWR nuclear power plant of the same scale, according to the relevant literature research of Zhang et al., in the total construction cost of a PWR nuclear power plant, the proportion of the reactor body (and internals) is very limited, about 2%, so it is influential.

Compared with the PWR nuclear power plant of the same scale, even if the reactor cost of the demonstration power station of HTR nuclear power plant is increased to 65,438+00 times, the increase of the total construction cost of the whole power station can be controlled within 20%.

Sodium-cooled fast reactor: In addition to its inherent safety, it also has the advantages of nuclear fuel diffusion, improving utilization rate and minimizing nuclear waste.

Improving the utilization ratio of nuclear fuel: The fast reactor technology uses mixed oxide of uranium and plutonium (MOX). In the fast reactor, the fuel area in the core is fission plutonium 239, and uranium 238 is placed in the peripheral regeneration area of the fuel area.

Plutonium -239 will release more fast neutrons during nuclear fission reaction. These fast neutrons will not only maintain the nuclear fission chain reaction of plutonium -239 itself, but also be absorbed by uranium -238 in the peripheral regeneration area.

Uranium -238 absorbs fast neutrons and becomes uranium -239, but uranium -239 is very unstable and becomes plutonium -239 again after two beta decays.

Therefore, when the fast reactor is running, the newly produced fission nuclear fuel is more than the consumed nuclear fuel, and the fuel is burned more and more, which is called proliferation reaction.

The proliferation reaction makes full use of uranium resources, and the environmental pollution caused by nuclear waste is expected to be solved, thus making the fourth generation nuclear power a nuclear energy utilization system with superior safety and economy, less waste, no off-site emergency and nuclear proliferation prevention ability.

3.2 Under the new nuclear power technology, the comprehensive application of nuclear energy becomes possible.

According to the research status and prospect of comprehensive utilization of nuclear energy published by China Academy of Sciences, from the perspective of energy efficiency, direct utilization of thermal energy is an ideal way, and power generation is only a form of nuclear energy utilization.

With the development of technology, especially the gradual maturity and application of the fourth generation nuclear energy system technology, nuclear energy is expected to surpass the role of providing electricity only, and play a huge role in ensuring the sustainable development of global energy and water security through various comprehensive utilization forms such as hydrogen production by nuclear energy, high-temperature process heat, nuclear heating and seawater desalination.

Hydrogen production by nuclear energy: Hydrogen production by nuclear energy is to use the heat generated by nuclear reactors as primary energy to prepare hydrogen from hydrogen-containing water or fossil fuels. At present, the mainstream technologies of hydrogen production from nuclear energy include thermochemical iodine-sulfur cycle, mixed sulfur cycle and high-temperature steam electrolysis, which realize the efficient conversion from nuclear energy to hydrogen energy and effectively reduce the efficiency loss during thermoelectric conversion. High temperature gas-cooled reactor (outlet temperature 700-950℃) and ultra-high temperature gas-cooled reactor (outlet temperature above 950℃) have the characteristics of intrinsic safety, high outlet temperature and appropriate power, and are the most ideal nuclear reactors for hydrogen production by high temperature electrolysis at present;

1) High temperature ceramic coated fuel has high safety.

2) Coupled with thermochemical cycle process. At 800℃, the theoretical hydrogen production efficiency of high temperature electrolysis is higher than 50%, and the efficiency will be further improved with the increase of temperature.

3) Nuclear heat-assisted hydrocarbon reforming uses the process heat of high-temperature gas-cooled reactor to replace the heat source in the conventional technology, which can partially reduce the use of fossil fuels and correspondingly reduce CO2 emissions.

4) It can be coupled with a gas turbine to generate electricity with an efficiency of 48%.

At present, CNNC, Tsinghua University and Baowu Group, etc. We have jointly carried out the initial cooperation of combining hydrogen production from nuclear energy with hydrogen metallurgy, and plan to carry out pilot verification during the Tenth Five-Year Plan period, and carry out demonstration of hydrogen production from nuclear energy in high-temperature reactors during the Tenth Five-Year Plan period.

Compared with different hydrogen production methods, high temperature gas-cooled reactor has cost advantage.

According to the nuclear hydrogen innovation plan, the U.S. Department of Energy made an economic evaluation of hydrogen production by nuclear energy, and the hydrogen cost was 2.94-4.40 USD/kg. In addition, the International Atomic Energy Agency has formulated a hydrogen economic evaluation plan, and the participating countries have made a scenario analysis of the cost of hydrogen production by nuclear energy. The cost of hydrogen obtained in different scenarios is 2.45-4.34 USD/kg.

Nuclear heating: Nuclear heating uses the steam extracted from the secondary circuit of the nuclear power unit as the heat source, carries out multi-stage heat exchange through the first heat exchange station in the plant and the heat exchange station of the off-site heating enterprise, and finally transmits the heat to the end users through the municipal heating pipe network.

From the safety point of view, in the whole heating process, there are multiple loops between the nuclear power plant and the heating users, and only heat is transferred between each loop, and hot water only circulates in the residential area, which is relatively safe. From the perspective of carbon emissions, nuclear energy, as a zero-carbon energy source, is much better than traditional thermal power plants burning coal for heating.

2021115 National Energy Nuclear Heating Commercial Demonstration Project Phase II 4.5 million square meters project was officially put into production in Haiyang, Shandong Province; 202165438+On February 3rd, Zhejiang Haiyan Nuclear Energy Heating Demonstration Project (Phase I) was officially put into operation in Haiyan, Zhejiang. In the long run, nuclear heating, as a zero-carbon clean heating method, has the potential of replication and promotion, and is also helpful to realize the goal of "double carbon" in China.

4. 1 Spent nuclear fuel needs to be properly disposed of, and China has confirmed the closed-loop route.

Spent fuel refers to irradiated and used nuclear fuel, which is produced by nuclear power plant reactors.

Nuclear fuel reacts in the reactor by neutron bombardment and is discharged from the reactor within a certain period of time.

The uranium content in spent fuel is low, which can not continue to maintain nuclear reaction, but it still contains a lot of radioactive elements, which need to be properly treated.

Spent fuel treatment methods are divided into "open nuclear fuel cycle" and "closed nuclear fuel cycle". The difference is that "open" directly cools and packages spent fuel and sends it to deep geological layer for disposal or long-term storage, while "closed" sends spent fuel to reprocessing plant to recover uranium, plutonium and other substances, and then solidifies the waste for deep address layer disposal.

In 1980s, China established the "closed cycle" route of nuclear fuel to improve the utilization rate of resources, reduce the volume of radioactive waste and reduce its toxicity.

4.2 The scale of spent fuel discharge continues to grow, and the first set of 200 tons/year treatment facilities is under construction.

The scale of spent fuel emissions has been expanding, and the contradiction between supply and demand has become increasingly prominent.

In the summary of the reply to the proposal, the National Energy Administration, issued by the Fourth Session of the 13th National People's Congress No.283/KLOC-0: 00019705/2021-00408) on July 5th, 20265438, said that the million kilowatt nuclear power units emit 20% of the spent fuel every year. According to the nuclear power installed capacity of 53.26 million kilowatts in China as of 202 1 and February, China will produce about 1065.2 tons-133 1.5 tons of spent fuel every year.

According to the statistics of China nuclear system think tank series (Volume III), in 2020, China will produce spent fuel 1 100 tons, and the accumulated amount of spent fuel has reached 8,300 tons. It is estimated that the cumulative quantity will reach 1 14500 tons by 2050.

With the continuous expansion and continuous operation of nuclear power, the scale of spent fuel emissions in China will continue to increase every year, and the sustainable development of nuclear power is bound to be inseparable from the related facilities for spent fuel reprocessing.

The first set of 200 tons/year treatment facilities is under construction. Under the urgent demand, there will definitely be development opportunities in the future.

According to the introduction of Jiangsu Shentong's plan for non-public offering of A shares, the first set of closed spent fuel treatment facilities under construction in China has a treatment capacity of only 200 tons/year, while the capacity of the reactor storage pool used for open nuclear fuel cycle has been overloaded, which is in sharp contrast to the relatively large annual output and accumulation of spent fuel.

In addition, as early as 20 16, the National Development and Reform Commission and the National Energy Administration clearly proposed to develop spent fuel reprocessing technology in the Action Plan for Energy Technology Revolution and Innovation (20 16-2030), and proposed to basically build the first large-scale commercial spent fuel reprocessing plant in China in 2030.

The development of China's nuclear power industry can not be separated from the synchronous improvement of the production capacity related to "closed nuclear fuel cycle treatment", and the market demand is more urgent, so it has definite development opportunities in the future.

Benefiting from the gradual realization of the favorable development of nuclear power, the prosperity of the whole nuclear power industry chain is expected to pick up.

Nuclear power is a typical heavy asset industry, which can obtain high-quality cash flow during the operation period. Taking advantage of high hours, low electricity cost, low carbon stability and high efficiency, it is expected to usher in a period of development opportunities under the background of carbon neutrality.

(1) Risk that the construction progress of nuclear power plant is less than expected: the construction period of nuclear power project is long, and if the construction period is extended for various reasons, the construction cost will rise sharply;

(2) Policy risk: The nuclear power industry is highly regulated by the government, and relevant policy changes may have an impact on the development of nuclear power;

(3) Nuclear safety risk: If a nuclear accident occurs worldwide, it will adversely affect the pace of project promotion and the long-term development space of nuclear power.

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