Research reveals China has built prototype nuclear reactor to power aircraft carrier

According to a satellite image analysis and Chinese government documents obtained by the Associated Press, China has built a land-based prototype nuclear reactor for large surface warships, a clear indication that Beijing is advancing its plans to build China's first nuclear-powered aircraft carrier. The Chinese navy is already the world's largest in terms of numbers and has been rapidly modernizing.

Adding a nuclear-powered aircraft carrier to its fleet would be a significant step in achieving its ambition to build a true "blue-water" navy capable of operating far from China's shores and posing a growing global challenge to the United States. “A nuclear-powered aircraft carrier would put China in the ranks of top-tier naval powers, which currently only includes the U.S. and France,” said Zhao Tong, a senior fellow at the Carnegie Endowment for International Peace in Washington. He added, “For the Chinese leadership, such a development would symbolize national pride, fuel domestic nationalism, and enhance China’s global image as a leading world power.”

Researchers at the Middlebury Institute of International Studies in California said they discovered this while investigating a mountainous site outside the city of Leshan in southwestern Sichuan province. They had previously suspected that China was building a reactor there to produce plutonium or tritium needed for weapons. But their conclusion is that China is building a prototype reactor for large warships. The Leshan project is known as the "Longwei" project and is also referred to in documents as the "Nuclear Power Development Project." Neither China's Ministry of National Defense nor its Ministry of Foreign Affairs responded to requests for comment.

There have long been rumors of China’s plans to build a nuclear-powered aircraft carrier, but the Middlebury team's research is the first confirmation that China is developing a nuclear propulsion system for a carrier-class surface warship. “The prototype reactor at Leshan is the first concrete evidence that China is actually developing nuclear-powered aircraft carriers. Operating nuclear-powered aircraft carriers is an exclusive club, and China appears to be on the verge of joining,” said Jeffrey Lewis, a professor at Middlebury University and one of the researchers on the project.

Researchers used satellite images and publicly available documents, including project tenders, personnel files, environmental impact studies, and even a citizen's complaint about excessive construction noise and dust, to conclude that a prototype reactor for naval propulsion is being built in the mountainous area of Muchuan County, about 112 kilometers southwest of Chengdu, the capital of Sichuan province. Procurement documents indicate that the reactor is nearing operation, located within a site called Base 909, which has six other reactors that are either operating, decommissioned, or under construction. The base is controlled by the China Nuclear Power Research Institute, a subsidiary of China National Nuclear Corporation, which is responsible for reactor engineering research and testing.

Documents show that the China Ship Research and Design Center (officially known as Institute 701), which is responsible for aircraft carrier development, procured reactor equipment "for installation on large surface warships" under the Nuclear Power Development Project, as well as the project's "defense designation," which helped conclude that this rather large reactor is a prototype for the next generation of aircraft carriers. Satellite images from 2020 to 2023 show that houses were demolished and water intake infrastructure connected to the reactor site was built. Contracts for steam generators and turbine pumps indicate that the project involves a pressurized water reactor with a secondary loop, consistent with the characteristics of naval propulsion reactors. An environmental impact report stated that the "Longwei Project" is a "defense-related construction project" classified as "confidential."

“Unless China is developing a nuclear-powered cruiser, which only the United States and the Soviet Union pursued during the Cold War, then the Nuclear Power Development Project must refer to the development of nuclear-powered aircraft carriers,” the researchers wrote in a detailed 19-page report. Jamie Wiseman, an analyst at the Oslo Nuclear Project who was not involved in the research but reviewed the findings, said the Middlebury team presented a "compelling argument." She said, “From the identification of the reports, the co-location with other naval reactor facilities, and the associated construction activities, I think it is fair to say that the Longwei project is very likely located at Base 909 and likely within the identified building.”

However, the research does not provide clues as to when China might be able to build and put a nuclear-powered aircraft carrier into service. Sarah Laderman, a senior analyst at the Open Nuclear Network of the U.S.-based NGO PAX sapiens Foundation, said the findings were "carefully conducted and thoroughly researched." She added, "Given the evidence provided here, I think there is a strong case to be made that China appears to be building a nuclear propulsion system at this site for its naval surface vessels, most likely an aircraft carrier."

China's first aircraft carrier, commissioned in 2012, was a refitted Soviet vessel, while the second was built in China but based on Soviet designs. Both ships — named the Liaoning and Shandong, respectively — use a so-called "ski-jump" takeoff system, which has a ramp at the end of a short runway to help aircraft take off. The Type 003 Fujian, launched in 2022, is China's third aircraft carrier and the first to be designed and built indigenously. It uses an electromagnetic catapult system similar to that developed and used by the U.S. Navy. All three carriers are conventionally powered.

The Fujian had not even begun sea trials in March when Yuan Huazhi, the political commissar of the People's Liberation Army Navy, confirmed the construction of a fourth aircraft carrier. When asked if it would be nuclear-powered, he said at the time that it would be "announced soon," but no announcement has been made so far. There is speculation that China may start building two new aircraft carriers simultaneously — a Type 003 like the Fujian and a nuclear-powered Type 004 — which it has not attempted before, but its shipyards have the capacity to do so. Matthew Funaiole, a senior fellow with the China Power Project at the Center for Strategic and International Studies, said he doubts China’s next aircraft carrier will be nuclear-powered.

Instead, he said he expects the PLA Navy's fourth aircraft carrier to focus on optimizing the existing design of the Fujian and making "incremental improvements." Nick Childs, a senior fellow for naval forces and maritime security at the International Institute for Strategic Studies, said China "has taken a gradual approach to its carrier development and has developed a number of ambitions over time." He said, "At the moment, their deployments are relatively cautious, mainly within the range of shore support, but projecting influence and to some extent coercion within their near seas."

Ultimately, Childs said, "larger aircraft carriers more akin to their U.S. counterparts will give them more power projection options." It takes years to build an aircraft carrier and bring it into service, but developing nuclear power for its next generation of warships will eventually give China greater capacity to operate advanced systems such as electromagnetic catapults, radars, and new technology weapons. "Not only does nuclear power remove the need for regular refueling of the ships, thereby vastly increasing their range, but it also means there will be space on board for fuel and weapons for aircraft without the need to carry fuel for the ship, thus expanding its capabilities," Childs said.

“Much depends on the overall size of the next carrier, but the addition of nuclear power would represent a major step forward in China’s aircraft carrier development, bringing its ships closer to those of the U.S. Navy,” Childs said. Zhao Tong of the Carnegie Endowment for International Peace said that a nuclear-powered aircraft carrier would give the Chinese military "greater flexibility and endurance to operate in strategic hotspots, particularly along the 'first island chain,' where China has most of its territorial disputes." The first island chain includes the self-governed island of Taiwan, which China claims as its own and has vowed to annex by force if necessary.

The United States is obligated under domestic law to provide Taiwan with sufficient weapons to deter an invasion and could provide aid to the island from its bases in the Pacific in the event of an invasion or blockade. Tensions are also rising in the South China Sea between China and its neighbors due to territorial disputes and maritime claims. "These aircraft carriers could also extend China’s operations into the broader western Pacific, further challenging the ability of the U.S. military to 'intervene' in regional affairs that China believes are best addressed by countries in the region," Zhao said.

Chinese President Xi Jinping has tasked defense officials with building a "first-class" navy and building it into a maritime power as part of his blueprint for national rejuvenation. The country's most recent defense white paper, dated 2019, states that the Chinese navy is adjusting its strategic requirements to "accelerate its shift from near-shore defense to far-seas protection missions." The PLA Navy is already the world's largest navy, with more than 370 ships and submarines. The country also has strong shipbuilding capacity: according to a U.S. Congressional report late last year, Chinese shipyards build hundreds of ships each year, while the U.S. builds five or fewer.

However, the Chinese navy lags behind the U.S. Navy in many respects. Among other advantages, the U.S. currently has 11 aircraft carriers, all nuclear-powered, allowing it to deploy multiple strike groups around the world at all times, including in the Indo-Pacific region. But the Pentagon is increasingly concerned about the rapid modernization of the Chinese fleet, including the design and construction of new aircraft carriers. The Department of Defense, in its recent report to Congress on the Chinese military, said this is in line with China's "growing emphasis on maritime domains and its increasing requirements for its navy to operate 'at greater distances from the Chinese mainland.'"

The report said that China’s “growing aircraft carrier force will extend the air defense coverage of deployed task forces beyond the range of land-based defenses, enabling them to operate further from China’s shores.”