When the first nuclear power unit using Hualong One, the first China-designed reactor, started commercial operations on January 30, it heralded a series of breakthroughs. It symbolized progress in third-generation nuclear technology, propelling China into the rank of leading nuclear power technology providers such as the United States, France and Russia. It advanced China on its target path of achieving carbon neutrality and signaled an upgrade in manufacturing with heightened safety features.

Thirty years of experience in research, design, manufacturing, construction and operation went into the making of Hualong One, giving China completely independent intellectual property rights. All its over 400 core parts have been domestically produced, paving the way for mass manufacturing and export.

Construction of the unit in a nuclear power plant in coastal city Fuqing in Fujian Province, southeast China, started in 2015. It was connected to the grid on November 27, 2020, and underwent a series of tests and trial runs in the following two months. The unit is expected to generate nearly 10 billion kWh of electricity annually, enough to meet the annual production and daily electricity needs of moderately developed countries with more than 1 million people. The green power will be equivalent to reducing consumption by 3.12 million tons of standard coal equivalent per year and reducing carbon dioxide emissions by 8.16 million tons, or the oxygenation effect achieved by planting more than 70 million trees.

Farewell to imports

"In the early days, key nuclear power parts, from a screw to a pressure vessel, had to be imported," Liu Wei, former General Manager of China Nuclear Power Engineering Co. (CNPEC), said. "Technology was a choking point in our development of nuclear power as core technology can't be bought or exchanged. So we decided to pursue domestic production to become self-reliant."

Of all the components, Liu called the main pump the heart of the reactor and the toughest part. It powers the entire system and is extremely hard to manufacture due to its complex and sensitive structure. Before 2008, China imported all the main pumps used in its nuclear power plants.

Since at that time Chinese companies lacked the skills to design, manufacture, test and manage the main pump, the CNPEC set up a special team with foreign experts who mentored the Chinese researchers. Many Chinese employees were sent abroad to study the processes.

"In the decade from 2008 to 2018, homegrown main pumps have made progress. The main pump of Hualong One, with almost all of its core components produced domestically, has a design life of 60 years," Liu said.

But for Wu Lin, former Vice President of the Nuclear Power Institute of China (NPIC), the domestic manufacturing of the steam generator of Hualong One, another core component which produces the steam for driving the turbine, signifies the most impressive progress in domestic capability.

For a long time, only a few foreign companies possessed the technology to design the steam generator. China lacked the advanced design needed for mega-kilowatt nuclear power plants. To overcome this challenge, the NPIC raised funds on its own and formed a research team to design the part. The team leader, Zhang Fuyuan, had 30 years of experience in this field.

The dedicated team produced the advanced third-generation steam generator in less than three years. The ZH-65 model produces higher steam pressure, lower steam humidity and is more economical compared to its foreign counterparts.

"Hualong One has driven the overall upgrade of China's manufacturing industry. More than 5,000 enterprises in the industrial chain produced the 411 homegrown core equipment, achieving 88 percent domestication of the reactor. It is a leap forward from a manufacturing country to an innovative one," Liu said.

The safety factor

Since research started on developing Hualong One in the 1990s, one of the priorities was ensuring the highest level of safety. The disaster in Japan in 2011, when an earthquake combined with a tsunami caused an accident at the Fukushima Daichi nuclear power plant, has been a warning since then worldwide to ensure the utmost safety of nuclear power plants, factoring in potential natural hazards.

"Hualong One has the highest safety measure possible," Xing said. "It meets all the requirements set by the International Atomic Energy Agency (IAEA) and the third-generation nuclear power technical standards of the U.S. and Europe."

The ACP-1000, the design of the reactor, has a higher peak ground acceleration (PGA) resistance standard than the level required for European reactors. PGA is the maximum force experienced by bodies on the ground during an earthquake. Also, the September 11 terror attacks in the U.S. in 2001, in which three planes were actively used to attack key buildings, reminded designers that nuclear reactors must be able to withstand potential large aircraft impact.

"We redesigned the ACP-1000 so that it can withstand extreme external disasters as well as human-induced ones," Xing said. "After the September 11 terror attacks, the possibility of large aircraft collisions has been generally factored into the design of third-generation nuclear power reactors in Europe. It was part of our agenda as well."

This was another extremely difficult task as such models and parameters are highly confidential and no information is available outside the manufacturing companies. After a period of exploration, the research team decided to use three-dimensional models to simulate such situations, analyze the results and then estimate how to deal with them.

"Every step in technological innovation involves taking risks. Our work is to minimize them," Xing said.

In August 2014, Hualong One passed inspection by a national panel. In December that year, it was certified by the IAEA. In addition to the one in Fuqing, another five power units using the Hualong One technology are being built around the world.

Despite the progress, Xing regards the development of homegrown third-generation nuclear power technology as just the foundation. Much more needs to be done still. China now needs to formulate its own Hualong standard to take the lead in the technology and exporting it, according to him.

"We should establish our own standards of nuclear power equipment manufacturing to ensure that we are not dominated by other countries," he said.

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