Wikipedia Deep Dive

Hualong One

12 min read

China built a nuclear reactor from scratch in five years and brought it online in 2021. To put that in perspective, the United States hasn't completed a new nuclear plant in decades, and the ones under construction have been plagued by delays that stretch a decade or more.

The reactor is called Hualong One, which translates to "China Dragon Number One." The name carries a certain swagger, and perhaps deservedly so. This isn't some knockoff technology hastily assembled—it's a Generation III reactor, the most advanced class of commercial nuclear power plants in operation today, and Chinese regulators insist that every piece of intellectual property belongs to China.

What Makes a Generation III Reactor Special

Nuclear reactors are categorized into generations, much like smartphones or jet fighters. The earliest reactors, built in the 1950s and 1960s, were Generation I—experimental designs that proved nuclear power could work but weren't particularly efficient or safe by modern standards. Generation II reactors, which make up the bulk of the world's nuclear fleet today, improved on those designs with standardized components and better safety systems. These are the workhorses that have been humming along since the 1970s and 1980s.

Generation III reactors represent a fundamental leap forward. They're designed to be simpler, safer, and longer-lasting. The Hualong One, for instance, has a design life of sixty years—that's six decades of continuous operation before anyone needs to think seriously about decommissioning. Compare that to the forty-year lifespans typical of earlier designs.

But the real innovation in Generation III reactors is something called passive safety.

Traditional nuclear plants rely on active safety systems—pumps, valves, and backup generators that kick in during emergencies. The problem, as the Fukushima disaster demonstrated with devastating clarity, is that active systems can fail. When the tsunami knocked out Fukushima's backup generators, the pumps couldn't circulate cooling water, and the reactors melted down.

Passive safety systems work differently. They use natural forces like gravity and convection—the tendency of hot fluids to rise and cool fluids to sink—to keep the reactor safe without requiring electricity or human intervention. If something goes wrong, physics itself steps in to prevent catastrophe.

The Hualong One uses both. It combines active safety systems (multiple redundant trains of pumps and cooling circuits) with passive systems that can handle emergencies even if the power goes out entirely. Belt and suspenders, as engineers like to say.

A Marriage of Convenience

The Hualong One didn't spring fully formed from a single brilliant design team. It's actually the product of a shotgun wedding between two competing Chinese nuclear corporations, and understanding this history explains some of the reactor's distinctive features.

China has two major state-owned nuclear companies: the China National Nuclear Corporation (known as CNNC) and the China General Nuclear Power Group (CGN). Both trace their lineage back to French reactor technology—specifically a design called the M310 that France exported to China in the 1990s for the Daya Bay nuclear plant near Hong Kong.

From that common ancestor, the two companies went in different directions.

CNNC developed a design called the ACP-1000, emphasizing domestic components and incorporating ideas from the American Westinghouse AP1000 reactor, particularly its passive safety features. CGN developed the ACPR-1000, which stuck closer to the original French blueprint and drew inspiration from the European EPR reactor, favoring multiple redundant active safety systems.

By 2012, Chinese nuclear regulators had grown tired of this duplication. Having two competing designs meant splitting research budgets, fragmenting supply chains, and complicating export efforts. The government essentially told CNNC and CGN to get in a room and merge their designs.

The resulting hybrid took the best from both parents. From CNNC's design, it inherited a larger reactor core with 177 fuel assemblies (compared to CGN's 157), which means more uranium fuel generating more power. It also got CNNC's emphasis on passive safety systems and increased containment volume—the reinforced concrete shell around the reactor that serves as the last line of defense against radiation release.

From CGN's design, it inherited the option for three active safety trains—independent backup systems that can each handle an emergency on their own. Two is the minimum for redundancy; three is extra insurance.

The merged design was originally going to be called ACC-1000. Someone apparently decided that name lacked poetry, and so in 2014 it became Hualong One. China Dragon Number One sounds considerably more impressive on the international stage.

Double Containment and Other Safety Features

One feature worth understanding is double containment. Most nuclear reactors have a containment building—an enormously thick concrete and steel structure designed to keep radioactive material inside even if the reactor vessel itself fails. The Hualong One has two of these nested inside each other.

The inner containment is a pre-stressed concrete cylinder designed to withstand the pressure surge from a major accident. The outer containment provides additional protection against external threats—aircraft impacts, earthquakes, explosions. The space between the two shells is maintained at slightly lower pressure than the atmosphere, so any leakage flows inward rather than outward.

This double-shell approach isn't unique to China—the French EPR reactor uses it too—but it represents the state of the art in containment design. It's expensive to build, but it provides multiple barriers against the nightmare scenario of radioactive release.

The reactor also operates on an eighteen-month refueling cycle, which is significant for practical reasons. Nuclear plants have to shut down periodically to replace spent fuel assemblies with fresh ones. The longer you can go between refuelings, the more electricity you generate. Eighteen months is toward the longer end of typical refueling intervals, meaning the Hualong One spends more of its life actually producing power.

CNNC claims the reactor achieves a 90% capacity factor—meaning it produces 90% of the electricity it theoretically could if it ran at full power every moment of every day. That's excellent by industry standards. Wind farms typically achieve 25-35%, solar around 20-25%, and even efficient gas plants rarely top 80%. Nuclear's high capacity factor is one of its key economic advantages.

The Cost Question

Here's where things get interesting, and contentious.

CNNC reports that the Hualong One costs 17,000 Chinese yuan per kilowatt of capacity to build. At current exchange rates, that's roughly $2,400 per kilowatt. To grasp what this means, consider that the Vogtle nuclear plant in Georgia—the only nuclear plant under construction in the United States—is coming in at around $15,000 per kilowatt, more than six times higher.

Even accounting for the fact that Chinese labor is cheaper and regulatory processes faster, the gap is staggering. If the Chinese figures are accurate, it would mean nuclear power in China costs about the same to build as natural gas plants in the United States, and considerably less than offshore wind.

Western analysts debate these numbers endlessly. Are the Chinese figures accurate? Do they include all the same costs that American estimates do? Is the Chinese government subsidizing construction in ways that don't show up in official figures?

These are fair questions without easy answers. China's nuclear industry benefits from standardization—building many copies of the same design drives down costs through learning and economies of scale. It benefits from a streamlined regulatory process that doesn't involve the decades of litigation and permitting battles common in Western countries. And it benefits from state ownership, which eliminates the cost of private capital.

But even skeptics acknowledge that China is building nuclear plants far faster and cheaper than anyone in the West. Whether the exact cost is $2,400 per kilowatt or $4,000 per kilowatt, it's still a fraction of American costs.

Global Ambitions

China doesn't just want to build nuclear plants at home. It wants to sell them abroad.

The export version of the Hualong One is called HPR1000 (the letters stand for Hualong Pressurized water Reactor). In 2015, CNNC and CGN formed a joint venture called Hualong International Nuclear Power Technology Company specifically to market this reactor overseas.

Pakistan was the first customer. Four Hualong One reactors are under construction at the Karachi Nuclear Power Complex, with a fifth planned for the Chashma Nuclear Power Plant. Pakistan has long relied on Chinese assistance for its nuclear energy program—and, more controversially, for its nuclear weapons program, though those are separate facilities.

Argentina was supposed to be next. Negotiations began for a Hualong One at the Atucha nuclear site, with construction originally scheduled to start in 2020. The project stalled during the pandemic and amid Argentina's recurring economic crises, but was reportedly reactivated in 2021 with a targeted completion date of 2028. Whether that timeline holds remains to be seen.

The most symbolically significant potential customer is the United Kingdom.

In February 2022, British regulators announced that the HPR1000 had passed their Generic Design Assessment—a rigorous four-and-a-half-year review process that examines everything from reactor physics to safety systems to environmental impact. The UK's Office for Nuclear Regulation issued a Design Acceptance Confirmation, and the Environment Agency issued a Statement of Design Acceptability.

This means the Hualong One is legally cleared for construction in Britain. The proposed site is Bradwell B, on the Essex coast about fifty miles northeast of London.

Whether it will actually be built is another matter entirely.

The politics have grown complicated. When the Bradwell deal was negotiated in 2016, UK-China relations were warmer, and the British government was eager for Chinese investment in infrastructure. Since then, tensions over Hong Kong, Xinjiang, and technology security have chilled the relationship considerably. Many British politicians now question whether allowing China to build a nuclear plant on British soil is wise, regardless of the technical merits.

The European Utility Requirements organization, an industry body representing European nuclear operators, also certified the HPR1000 in November 2021 after its own four-year review. This certification doesn't grant regulatory approval—that still requires individual countries to conduct their own assessments—but it signals that the reactor meets European safety standards and could theoretically be built anywhere in Europe.

The Chinese Nuclear Buildout

While export deals generate headlines, the more consequential story is what's happening inside China itself.

The first Hualong One to enter commercial service was Unit 5 at the Fuqing Nuclear Power Plant, located in Fujian Province on China's southeastern coast. It began generating electricity for the grid on January 30, 2021. Unit 6 followed, and CGN's first Hualong One (a slightly different variant reflecting its heritage from the ACPR-1000) connected to the grid on January 10, 2023.

But Fuqing is just the beginning. China's State Council—the country's top administrative body—has approved Hualong One units at multiple sites: Fangchenggang in Guangxi Province near the Vietnamese border; Zhangzhou, also in Fujian; Taipingling in Guangdong, the economic powerhouse province containing Shenzhen and Guangzhou; San'Ao in Zhejiang, the coastal province south of Shanghai; and Ningde and Shidaowan.

Each site typically gets two or more units, because nuclear plants benefit enormously from being built in pairs or clusters. The same construction teams, the same supply chains, the same operating staff can serve multiple reactors, driving down per-unit costs.

The scale of this buildout is difficult for Western observers to fully appreciate. While the United States struggles to complete a single new nuclear plant after decades of construction, China is building them by the dozen. The Chinese nuclear industry has made a deliberate choice to standardize on a few proven designs and then replicate them relentlessly, learning and improving with each iteration.

What Comes Next: Hualong Two

Even as Hualong One reactors multiply across China, engineers are already working on the successor.

CNNC has announced plans to begin construction on Hualong Two by 2024. The design philosophy is not revolutionary but evolutionary—take what works in Hualong One and make it cheaper and faster to build.

The target numbers are ambitious. CNNC wants to reduce construction time from five years to four, and cut costs by roughly a quarter, from 17,000 yuan per kilowatt to 13,000 yuan per kilowatt. At current exchange rates, that would be around $1,800 per kilowatt—cheaper than almost any other form of electricity generation except perhaps combined-cycle natural gas in regions with cheap fuel.

How do you cut costs by 25% while maintaining safety? The details aren't fully public, but the general approach involves simplifying construction through modular manufacturing (building more components in factories rather than on-site), optimizing the supply chain, and incorporating lessons learned from the first generation of Hualong One plants.

This iterative improvement is characteristic of how China approaches large-scale technology projects. The first version is good enough to deploy; subsequent versions get progressively better and cheaper. It's the same approach that made China dominant in solar panels, wind turbines, and electric vehicles.

The Bigger Picture

The Hualong One represents something larger than just one reactor design. It's a proof of concept for a different model of nuclear development.

In the West, nuclear power has become synonymous with cost overruns, schedule delays, and regulatory quagmires. Each new plant is essentially a custom construction project, subject to endless design changes, litigation, and political interference. The last nuclear plant completed in the United States before Vogtle, the Watts Bar 2 reactor in Tennessee, took twenty-three years from groundbreaking to commercial operation.

China has demonstrated that nuclear plants can still be built on schedule and on budget—or at least close to it. The key ingredients appear to be standardization (building the same design repeatedly), regulatory streamlining (maintaining rigorous safety standards while eliminating procedural delays), and sustained political commitment (treating nuclear as a strategic priority rather than a political football).

Whether this model can be replicated in democratic societies with independent regulators and robust civil society is an open question. The Chinese system has real advantages for large infrastructure projects, but it also has costs that don't show up in construction budgets—costs related to transparency, public participation, and accountability.

What's undeniable is that China now leads the world in nuclear construction. The country that couldn't build a reactor without French assistance thirty years ago now exports its own designs and lectures Western nations about safety standards. The Dragon has learned to breathe fire.