Black technology starts from the steel suit

Chapter 238 Prospects of 238 Fourth Generation Heap
Professor Wang, in fact, I came here today not only for these things, but also for one more thing. Director Lu suddenly said seriously.

"They are all making contributions to the country. If there is anything you can't ask for, your Excellency is serious." Wang Feng sat upright and said.

"No, no, logically speaking, you shouldn't bother you. This should be a matter for us old men, but this technology has not been broken through for a long time, and we are all very anxious!" Director Lu felt a little helpless. Said.

"Don't worry, there is no rush for scientific research." Wang Feng picked up the teapot and poured a cup of tea for the other party, and then continued: "I don't know what it is that makes you so anxious. Is it more important than the spent fuel processing device?" ?”

"It is true that the spent fuel processing device has only opened the door to the nuclear age, but if you want to step in, you need a key technology."

Wang Feng:? ? ?
With all due respect, I really don't know any other key technology, it can't be the nuclear technology itself, right?

"Professor Wang is a great scientist. He must know what fuel our current nuclear technology burns. In nature, only uranium 235 can naturally undergo fission, and this nuclide only accounts for 0.7% of uranium."

"Indeed, in addition to uranium 235, there are also uranium 233 and plutonium 239 that can naturally fission, but they are too small, so they are not included." Wang Feng added.

"Before this, these nuclides could only be purified, that is, the uranium-238 and uranium-235 were separated by a centrifuge, and then the fission reaction could proceed."

"Uranium 235 is usable fuel, but uranium 238 is wasted, and the nuclide with the largest proportion is wasted directly."

"Yeah, it's really a pity."

"Professor Wang, you are an expert, you should have heard of the technology of utilizing uranium-238, right?"

"Indeed, isn't that what fourth-generation nuclear technology is here to do?"

Solving air pollution and global warming has now become a topic of concern all over the world, and the most important solution is to control the use of ordinary fossil energy and vigorously develop and use various renewable clean energy.

Solar energy, water energy, wind energy, geothermal energy, etc. are all very good clean energy sources, but compared with these clean energy sources, nuclear energy obviously has more advantages, and can almost meet the requirements of zero emissions.

Therefore, many countries around the world are vigorously developing nuclear energy, and our country also regards nuclear energy as the main clean energy in the future.

The concept of the fourth-generation nuclear power reactor Gen-IV was first proposed in June 1999 at the annual meeting of the American Nuclear Society.

At the winter annual meeting of the society in November of that year, the idea of ​​developing Gen-IV was further clarified.The United States, France, Japan, the United Kingdom and other nuclear power developed countries established the Gen-IV International Forum in 11, and planned to complete the formulation of the Gen-IV R&D target plan within 2000 to 2 years.

The overall goal of this plan is to provide Gen-IV to the market around 2030 that can well solve the problems of nuclear energy economy, safety, waste disposal and nuclear non-proliferation.

Realizing the harmonious coexistence and sustainable development between man and nature is the ideal realm pursued by human beings.In China's splendid 5000-year-old culture, the concept of the unity of man and nature runs through all the time.In the process of pursuing industrialization in various countries in the world, the contradiction between energy and environment has emerged, and the mode of energy supply is not sustainable, and major adjustments must be made.Sustainable development has become the primary issue that mankind faces after entering the new century.

It has been noted that competitive pressures in electricity markets may adversely affect the operational safety of nuclear power.But research shows a strong correlation between the most successful commercial nuclear plants and the safest.The accidents at the Three Mile Island Nuclear Power Plant and the Chernobyl Nuclear Power Plant and their effects proved that nuclear safety is the lifeline of the development of the nuclear industry.Safety and reliability have become an integral part of the commercial requirements of nuclear power plants.

Increasing competition in electricity markets in most countries of the world is forcing electricity producers and their suppliers to pay more attention to their operating costs and the profitability of their investments.The existing nuclear power system appears to be too high in initial investment, too long in construction period and too large in project scale in such a market.For the nuclear industry to survive and prosper, it needs a commercial, profit-oriented approach.

On the whole, nuclear power has competitive potential in the mid-term and long-term markets.However, for this potential to become a reality, great efforts must be made in many aspects, including the need to significantly reduce costs, including operation and maintenance expenses, without compromising safety, and to increase the availability of power plants. reach a higher level.

Facing the above challenges, the international nuclear energy community is conducting various researches and adjustments, one of which is the research and development of the fourth-generation nuclear energy system.Including relevant national governments, industrial circles, power companies, universities, laboratories, and research institutes all pay attention to or participate in this research and development to varying degrees.Annual research and development costs exceed $20 billion.

According to a widely accepted view, the existing nuclear energy systems are divided into three generations:
(1) The first batch of prototype nuclear power plants built in the late 50s and early 60s;

（2）60年代至70年代大批建造的单机容量在600~1400 MW的标准型核电站，它们是世界上正在运行的439座核电站（2002年6月统计数）的主体；

(3) The advanced light water reactor (ALWR) nuclear power plant that was developed in {BANNED} in the 80s and put into the market in the late 90s.

The concept of Gen-IV advanced nuclear energy system is still relatively vague, and there is no exact definition internationally.However, it is already clear that "advanced nuclear energy system" is not "advanced reactor".It should meet the basic criteria of safety, economy, sustainable development, minimal waste generation, and low risk of fuel multiplication.

Specifically, there are three types of goals for developing Gen-IV:

sustainability goals

According to a more authoritative definition, the essence of sustainable capacity is how to maintain the earth's survival support system to meet the basic needs of human beings.For a specific system, it is the probability that it can successfully constrain its development, coordination, and sustainability within the threshold of sustainable development within the specified goals and preset stages, that is, it can successfully extend to the sustainable development threshold. Sustainable Development Goal Capabilities. Sustainability goals for Gen-IV include efficient use of fuel, waste management, and physical limitation of nuclear proliferation.Right now:

Sustainability Goal 1: Gen-IV will provide the world with sustainable energy that meets clean air requirements, is long-term reliable, and uses fuel efficiently.

Sustainability Goal 2: Gen-IV generates minimal amounts of nuclear waste; waste management is conducted in a manner that will both safely dispose of the waste and significantly reduce doses to workers, thereby improving public health outcomes and environmental protection.

Sustainability Goal 3: Gen-IV will limit the possibility of nuclear proliferation caused by the commercial nuclear fuel cycle to a minimum, making it difficult to convert it to military use, and provide more physically effective measures to prevent terrorist activities.

Safety and Reliability Goals

In the development and operation of nuclear energy systems, safety and reliability are the basic factors that are given priority.Under normal operation or hypothetical transient conditions, nuclear energy systems must maintain their safety margins, prevent accidents, and have effective accident mitigation measures.At the same time, high operational reliability is required.

Over the years, it has been a clear trend to improve the safety and reliability of nuclear energy systems, reduce the frequency and degree of off-site radioactive releases, and reduce the probability of severe accidents. Gen-IV needs to achieve higher safety and reliability through further improvement, and better protect the health of employees, the public and the environment.In this regard, Gen-IV also has three goals:

Safety and reliability goal 1: Gen-IV will be significantly better than other nuclear energy systems in terms of safe and reliable operation.

This objective is to improve the safety of operations by reducing the number of incidents, equipment problems and human factors that can cause accidents or cause accidents to become severe.This goal also improves the economics of nuclear energy systems by enhancing reliability.Requirements and careful design are required to achieve these operational goals and support a demonstration of safety that enhances public confidence.

In order to achieve the highest level of safety and reliability, Generation IV nuclear energy systems must continue to adopt the relevant regulations established by industry and regulators to enhance public confidence, and adopt future advanced technologies.

Economic goals

Gen-IV will take significant steps to reduce the investment costs and financial risks of new nuclear power plants, whose sustainability, safety and reliability benefits would otherwise be overwhelmed by higher capital and generation costs and associated higher risks.For a long time, nuclear power plants have mainly operated with base load.

This situation is changing. The global energy market is transitioning from regulation to deregulation. More independent power generation companies and commercial power plant owners (operators) will enter the deregulated electricity market.

This means that more potential plant owners are considered for nuclear power plants under development, and future nuclear energy systems are adapted to different requirements, including load following and smaller units.The economic competitiveness of most nuclear power plants that have been built or are under construction in my country is not ideal.With the development of my country's energy industry and the continuous deepening of power system reform, the demand for improving the economics of nuclear power will become more urgent.

The unit cost of new nuclear power plants ($1500~2000/kW, which is 2~4 times the unit cost of fossil fuel power plants) and the long construction time, approval time, and decommissioning time are incomparable with other power production methods.

Having said so much, in fact, the key issues are nothing more than three points. One is the safety issue, which is a cliché; the second is the breeder reactor, which realizes the value-added of nuclear fuel and improves the utilization efficiency of nuclear fuel; the third is to benefit picture.

"The fourth-generation reactor!" Wang Feng said with emotion after reading the materials.Only we know how much we have paid in these years from being poor to being a nuclear power.

"We have basically mastered the technology of the third-generation reactor, and now we can export nuclear power technology, so the safety problem is basically not big, but we have never been able to break through the proliferation." Director Lu felt helpless said.

The problem he mentioned is not a problem of individuality, but a problem of commonality in the whole world.

"Although we have done some work, the work is far from ideal." Director Lu showed some materials to Wang Feng.

"Many of these things should be kept secret, I think it's appropriate?" Wang Feng evaded.

"If you are not suitable, then there is no suitable person." Director Lu smiled. For a scientist like Wang Feng, if he is not suitable, then there is really no suitable person.

"Looking at what you said, my level is only average, thanks to everyone's love." Wang Feng was polite, and then picked up the materials.

At present, the capacity of nuclear power units under construction in China has ranked first in the world for many years, and the technologies of these nuclear power plants are at the highest level in the world, such as the high-temperature gas-cooled reactor technology used in the fourth-generation nuclear power plants.

High-temperature gas-cooled reactor nuclear technology is the fourth-generation nuclear technology with high safety. It is one of the sixteen major scientific and technological projects in my country, just like the lunar exploration process, deep-sea diving and large aircraft. Its importance is self-evident .

The reason why it is called a high-temperature gas-cooled reactor is that it does not use water in the cooling process, but uses helium, an inert gas, for cooling. The main feature of using helium is that it can fully absorb heat, resulting in a high temperature of more than 700 degrees. The water-cooled reactors commonly used now can only produce high temperatures of more than 300 degrees.

A higher temperature can be generated at the outlet, which can also make the power generation efficiency higher. Using high-temperature air cooling can increase the power generation efficiency by more than 30%. It is currently the most efficient nuclear reactor.

Its reactor uses a furnace-shaped device made of high-temperature-resistant graphite and carbon bricks. The interior is filled with round fuel balls made of high-temperature-resistant graphite, and the radioactive substances that generate high temperatures are It is made into smaller particles and put into fuel balls.

High-temperature gas-cooled reactors can not only generate electricity, but also have a wide range of applications. They can also be used in petroleum, chemical industry, steelmaking and other fields. They can also provide high-temperature heat energy to these industries, so it has a broad market prospect.

The core of the high-temperature gas-cooled reactor is that it has high safety, which is one of the reasons why it is called the fourth-generation nuclear technology.

For example, when the temperature of the previous reactor was too high during operation, it would use water to cool it down, while the high-temperature gas-cooled reactor made the fuel into particles with a diameter of only 0.5 mm, and then dispersed it in the fuel made of high-temperature graphite. Inside the ball, as long as the temperature does not exceed 1600 degrees, all nuclear reactions are carried out inside the fuel ball, and there will be no leakage of reflective substances.

Moreover, some new substances will be added to the current fuel particles, such as uranium 238, which has very different characteristics from uranium 235. The rapid fission of uranium 235 is equivalent to adding a natural safety protection wall.

Moreover, after uranium 238 absorbs neutrons, it can become plutonium 239 that can be used as nuclear fuel, which can be said to kill two birds with one stone.

(End of this chapter)