Break the bottleneck of nuclear power technology development



Despite the obvious advantages, the safety issue of nuclear power is still its life. We should make full use of our country's relatively leading advantage in high temperature gas cooled reactor technology, continue to promote relevant technological research, explore the commercial application and commercial advantages of high temperature gas cooled reactor, and seize the commanding heights of the world's nuclear power technology.

Recently, the national science and technology major project - Huaneng Shidao Bay High temperature gas cooled reactor nuclear power plant demonstration project was successfully connected to the grid for the first time, sending out the first degree of electricity, marking the world's first spherical bed modular high temperature gas cooled reactor with the characteristics of the fourth generation of advanced nuclear energy system, achieving a qualitative leap from "laboratory" to "engineering application". It marks that China has become one of the few countries in the world to master the fourth generation nuclear energy technology, which means that China has become the leader of the world nuclear power technology in this field.

The completion of high-temperature gas cooled reactor is expected to open a new route for the application of nuclear energy and become a milestone in the history of human energy progress. As the global economic development continues to increase the demand for energy, people gradually realize that nuclear energy has a large energy density, nuclear power operation is stable, reliable, refuelling cycle is long, the production process almost does not produce carbon emissions, and can be used as a large-scale replacement of fossil energy base load power supply.

Despite the obvious advantages, nuclear power has a big "life gate" - safety. Historically, serious nuclear power plant accidents such as the Three Mile Island in the United States in 1979, Chernobyl in the Soviet Union in 1986, and Fukushima in Japan in 2011 have triggered greater social panic and cast a shadow over the development of nuclear power. It was realized that nuclear reactor cores must be sufficiently cooled at all times, otherwise serious accidents could result. To this end, nuclear power plants have added a variety of water injection and water refill systems, which include a large number of active components such as pumps and valves, and need to ensure the reliability of their power sources, which leads to more complex and large systems, greatly pushing up the cost and cycle of nuclear power construction. The development of nuclear power in the world has also reached a bottleneck.

The principle of nuclear power generation is not much different from that of thermal power plants, which use heat to "boil water", but the latter uses coal, gas, etc., to generate heat, and the former uses nuclear reactors to generate heat. Therefore, the development of the reactor technology with inherent safety, that is, the automatic cooling of the reactor does not rely on human intervention, but only uses the law of nature, has become the development goal that each reactor type has been pursuing. According to international standards, the fourth-generation advanced nuclear energy system has two core indicators: first, no matter what happens to the nuclear power plant, it will not cause damage to the public outside the station; Second, it is economically competitive with other power production methods.

The quasi-commercialization of high temperature gas cooled reactor is a key step to break the bottleneck of nuclear power development. High temperature gas cooled reactor, as the name suggests, refers to a nuclear reactor technology with high temperature characteristics and the use of gas for core cooling, and inherent safety is its core feature. Compared with other reactors, high-temperature gas cooled reactors produce less waste heat, only by natural heat dissipation can take away the heat of the core, and its fuel composition is also very special, can withstand the melting point of about 1600 ° C high temperature. Even if all cooling capacity is lost and a serious accident is faced, without any outside intervention, the reactor can remain in a safe state, and there will be no core meltdown accident, known as the "fool reactor".

While solving the safety problem, the power generation efficiency of high temperature gas cooled reactor has also been greatly improved. The exit temperature of coolant in nuclear reactor has a decisive effect on power generation efficiency. The average temperature of the helium outlet of the high-temperature gas cooled reactor can reach 750℃, and has the potential to increase to 950℃ or more. The thermal efficiency can reach 50% by using the helium circulation mode. Compared with a pressurized water reactor, the power generation capacity of a high-temperature gas cooled reactor is equivalent to 1.5 times that of a pressurized water reactor with the same thermal power.

The high-temperature gas cooled reactor adopts a small modular "LEGO" splicing design, which makes the use of nuclear power more convenient. We can build nuclear power plants like building blocks, this modular design and construction method can greatly shorten the construction cycle of nuclear power plants, while reducing construction costs. Based on the inherent safety characteristics, the high-temperature gas cooled reactor can also greatly simplify emergency measures, and the plant site is more adaptable, and it has the conditions for construction near large and medium-sized cities with relatively dense population.

More importantly, the high-temperature gas cooled reactor has greatly expanded the field of nuclear power utilization. The high temperature working medium produced by the high temperature gas cooled reactor can be used as a high temperature process heat source for coal gasification, liquefaction, technical smelting and other processes, district heating and seawater desalination, and can greatly reduce the cost of high temperature hydrogen production, forming a pollution-free, emission-free energy chain. Fractional utilization of waste heat can also reduce the operating cost of power station.

To promote energy transformation and achieve the goal of "dual carbon" is a complex systematic project, because each energy solution has its advantages and disadvantages, it is impossible to rely on a single type of energy to complete the transformation task. Given the scale of global warming and human development, nuclear power will remain an important part of the energy supply. The emergence of high-temperature gas cooled reactors has made it possible to build and utilize nuclear power as safely and efficiently as Lego, and its safety and economic advantages will have a major impact once proven in commercialization. In the face of the upcoming replacement of the global nuclear energy system, we should make full use of China's relatively leading advantages in high temperature gas cooled reactor technology, with the help of demonstration projects, continue to promote the technical research of high temperature gas cooled reactor, explore the commercial application and commercial advantages of high temperature gas cooled reactor, seize the commanding heights of the world's nuclear power technology, so that advanced nuclear power technology can better ensure energy security and serve carbon neutrality.