The "small guy" among the great power equipment of a great country - the mobile nuclear power bank "Linglong No. 1" is here!

The world's first commercial modular small reactor on land, "Linglong No. 1", successfully installed the upper steel containment shell of the reactor building. Will it become the future of domestic nuclear-powered aircraft carriers?

Written by reporter Wang Xueying, Photo and text editor Chen Yongjie

New Media Editor/Lv Bingxin

Recently, at the Changjiang Nuclear Power Base in Hainan, the upper steel containment cylinder of the reactor building of the Linglong No. 1, the world's first commercial modular small reactor on land, was successfully hoisted, laying a solid foundation for the high-quality promotion of small reactor project construction.

▲On July 6, the upper steel containment shell of the Linglong No. 1 reactor building was successfully hoisted (Photo source: China National Nuclear Corporation No. 5)

"Linglong No. 1" is currently the only third-generation nuclear power reactor in the world that has passed the official review of the International Atomic Energy Agency. It has the characteristics of miniaturized design, modular deployment, passive safety, and integrated technology. It has high safety, small footprint, short construction period, and is more environmentally friendly. It can be built close to cities and users. While providing electricity, it can also meet multiple purposes such as seawater desalination and industrial heating, and has more applicable scenarios.

Small, flexible and safe

When people mention nuclear power units, they always think of the image of "huge and clumsy". However, the "Linglong No. 1", which broke ground in July 2019, gave a new interpretation to the "nuclear power unit" - as the world's first third-generation small reactor that has passed the safety review of the International Atomic Energy Agency, the "Linglong No. 1" independently developed by China National Nuclear Corporation is the world's first commercial, multi-functional, modular small pressurized water reactor.

Unlike large reactors of the million-kilowatt level, Linglong No. 1, with a generating capacity of only 125,000 kilowatts, is at best a small reactor in terms of scale, according to the standard that "a reactor with a power below 300,000 kilowatts is a small reactor." However, "small" does not mean a poor level, on the contrary, being small has its own advantages.

▲ The first equipment of "Linglong No. 1" was hoisted into place (Photo source: China National Nuclear Corporation No. 5)

In this regard, Song Danrong, chief designer of Linglong No. 1 of CNNC, once made such a metaphor: "For the 'big pile', we can regard it as a home desktop computer, including a monitor, a host and a keyboard, while for the small pile, we can regard it as a laptop computer at home, with its monitor, host and keyboard all integrated together." In other words, although Linglong No. 1 is small in appearance, it is truly "small but complete in structure".

"The radius of Linglong No. 1 is about half of that of a 'big reactor'," said Yang Junhua, deputy chief of the civil engineering section of the Hainan Nuclear Power Engineering Department of CNNC. Conventional structural designs for nuclear power plants include ground-based and sunken layouts, while the small Linglong No. 1 reactor adopts a sunken design, and the core system is below the ground, so the project will be safer, "basically able to prevent collisions with large aircraft," he said.

It is understood that in order to further fully verify and ensure the safety of "Linglong No. 1", researchers have also built the largest passive safety system comprehensive test bench in Asia for testing, which is almost like putting a huge "golden bell" on the nuclear power unit. Specifically, the design of the passive safety system can, on the one hand, prevent accidents before they happen, that is, discover potential risks in advance during the design stage and reduce the possibility of danger; on the other hand, if extreme problems occur, such as the reactor losing power supply, the passive safety system can also use natural laws to ensure the safety of the reactor, and no human intervention is required for a long time after the accident.

Different "building blocks"

In addition to being small and sophisticated, the emergence of Linglong No. 1 also marks that my country has taken the lead in the world in small modular reactor (SMR) technology in the development of China's nuclear power. In this regard, many people can't help but ask, what exactly does "modularization" in the field of nuclear power mean?

Before talking about Linglong No. 1, we need to understand the concept of SMR. Since the Fukushima nuclear power plant accident, the world's attention to SMR has been growing. As one of its core concepts, "modularity" means that the reactor's systems and components can be assembled in the factory and transported to the installation site as a unit. In other words, SMR is like a huge Lego building block, which is finally pieced together by "small building blocks", and these "building blocks" are designed in advance according to standards, and then manufactured and mass-produced.

▲Construction site (Photo source: China National Nuclear Corporation No. 5)

Generally speaking, the construction of large power reactors is tailor-made by designers for a specific location. In contrast, since SMR is not a "customized product", it greatly reduces the cost of production and manufacturing, making it cheaper and more cost-effective than large power reactors. In theory, it can also greatly shorten the overall construction period of the project. It is understood that "Linglong No. 1" combines multiple components such as steam generators, reactors, main pumps and main pipelines into one, which is modularly manufactured and assembled in batches in the factory and then transported to the site for installation and commissioning.

"The modularity of Linglong No. 1 can reduce manufacturing costs and power," Song Danrong said. "Not only that, the integrated design of Linglong No. 1 can also reduce the accident rate, which greatly improves its safety." He said that because of its small size, Linglong No. 1 "has less nuclear fuel, which can reduce the impact of radioactivity," so its emergency planning area can be controlled within the boundaries of the plant. With these advantages, Linglong No. 1 can be "flexibly deployed closer to users, near towns and industrial parks," he said.

Super large "mobile power bank"

As the saying goes, "a sparrow may be small, but it has all the necessary organs." Compared with a nuclear power plant unit with a capacity of one million kilowatts, Linglong No. 1 is not only safer, more reliable, and more flexible, but also has a wider range of uses. "It can not only serve cities and industries, but also provide power for the development of marine resources, and even desalinate seawater," said Wang Yukun, an engineer at China Nuclear Power Company of CNNC, in an interview with the media.

Today, the upper steel containment shell of the Linglong No. 1 reactor building in Changjiang, Hainan has been successfully hoisted into place ahead of schedule, and the entire project is expected to be completed in 2026. As the Linglong No. 1 project progresses, people have more new expectations - can Linglong No. 1 be put on a broader stage, such as on the sea?

According to Wang Yukun, because of its small size and flexibility, Linglong No. 1 can also be installed on ships. "For example, when a ship carries it near an island, it can provide heating and even electricity for residents in the city, and it can also provide energy for industrial electricity and industrial power supply in the city," he explained. "As the ship continues to move forward and passes by an offshore drilling platform, the ship equipped with Linglong No. 1 can also provide energy and electricity for the drilling platform, and even provide energy for the development of the island."

▲The upper steel containment shell of the Linglong No. 1 reactor building is hoisted into place (Photo source: China National Nuclear Corporation No. 5)

Song Danrong believes that the idea of ​​turning Linglong No. 1 into a "mobile power bank at sea" has great potential. "In developed coastal areas and cities, land resources are very precious. If we build a reactor, the construction of facilities around it will definitely be limited," he said. "But if it is built at sea, three to five kilometers away from (land), and directly connected with electric wires and steam pipelines, it will not occupy a lot of land. Not only that, after putting it at sea, the cooling water needed by the reactor can actually be obtained locally."

From energy conservation and emission reduction to aircraft carrier military industry

Regarding small reactors, Ye Qizhen, an academician of the Chinese Academy of Engineering, once praised them as "game changers for nuclear energy", believing that they can provide different nuclear power cogeneration solutions in a safer way. The compact and exquisite "Linglong No. 1" will also open up unlimited possibilities for China's development in more areas.

First, in terms of energy conservation and emission reduction: As we all know, nuclear energy is an important green and low-carbon new energy source. The orderly promotion of nuclear power development is of great significance to my country's energy transformation and optimization of energy structure. According to official data, after its completion, "Linglong No. 1" is expected to reduce carbon dioxide emissions by 8.7 million tons and nitrogen oxides by 30,000 tons each year. At the same time, the annual power generation can reach 1 billion kilowatt-hours, meeting the living needs of 526,000 households for one year. In addition, with its low construction cost, high cost-effectiveness and flexible use, the promotion and application of "Linglong No. 1" will undoubtedly play an important role in my country's efforts to achieve "carbon peak" in 2030 and "carbon neutrality" in 2060.

The advantage of large reactors is mainly achieved through economic efficiency through power generation, while the advantage of small reactors is more reflected in heating, which is a distributed energy that relies more on site selection close to users. "Under the requirements of the global energy production and consumption revolution era of carbon peak and carbon neutrality, clean energy with good stability will have strong bargaining power," said Song Danrong.

In addition to helping energy conservation and emission reduction, Linglong No. 1 is also seen as an important force in promoting the development of my country's military industry, especially aircraft carriers. Because of its smaller overall size, Linglong No. 1 can theoretically be applied to the Liaoning and Shandong ships currently in service. Industry insiders previously speculated that given that the thermal power and electrical power of a single Linglong No. 1 can reach 385 megawatts and 125 megawatts respectively, if two units can be configured on my country's current aircraft carriers, it would be equivalent to providing the aircraft carrier with 280,000 horsepower - more than the Nimitz-class nuclear-powered aircraft carriers currently in service in the United States with 260,000 horsepower.

▲The Nimitz-class nuclear-powered aircraft carrier currently in service in the United States (Photo source/military.com)

Relevant experts pointed out that the "Linglong No. 1" may only be a civilian version, and it needs to be improved in terms of reactor size, power, and nuclear fuel abundance before it can be used on an aircraft carrier. But this can also provide a technical basis for the layout of future nuclear-powered aircraft carriers. We believe that we will definitely have our own nuclear-powered aircraft carrier in the future.

(Some text sources: CCTV Finance, China National Nuclear Corporation)

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Produced by: Beijing Science and Technology News | Beijing Science and Technology Media

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