Southeastern China’s Jiangxi province is going to build a fusion-fission power plant for more than 20 billion yuan (US$2.7 billion), with a target of continuously generating 100 megawatts (MW) of electricity.
Jiangxi Electronic Group, a state-owned enterprise, said in a statement on Tuesday that Lianovation Superconductor and CNNC Fusion (Chengdu) Design and Research Institute signed a cooperation framework agreement on November 12 to jointly build a fusion-fission reactor in the province.
Lianovation Superconductor is a unit of the Jiangxi Electronic Group. CNNC refers to the China National Nuclear Corp, also a state-owned-enterprise.
Chinese media said the fusion-fission reactor will be built in Jiangxi, instead of in a fusion energy hub such as Chengdu or Hefei, because Lianovation Superconductor is located in the province, which is famous for its copper resources.
Copper is a key metal for making superconductor materials, such as yttrium barium copper oxide (YBCO), that are used to make coils of magnets in reactors. Superconducting materials create no resistance for electric current to pass through at an absolute zero temperature (minus 273.15 degrees celsius).
According to Lianovation Superconductor’s website, the company is developing high-temperature superconducting (HTS) magnets that can operate at 20 degrees Kelvin (minus 253.15 degrees celsius).
Technology experts say HTS magnets will be commonly used in fusion reactors in future.
“The implementation of the project will be of great national strategic significance and is also a key measure to win the global future energy competition,” said the Jiangxi Electronic Group.
“The success of future projects will fundamentally solve the core problem of clean energy supply for the country, and will give birth to a new strategic emerging industry with epoch-making significance.”
The company did not provide a timetable or investment details for the project but it said it will target to achieve a Q value of more than 30 in this project. Presumably this value of Q applies to the fusion reactor part, which supplies neutrons to the fission process in the combined fusion-fission device.
The Q value, or the fusion energy gain factor, refers to the ratio of thermal power output to input in a fusion reaction. If Q equals to one, the reactor achieves plasma energy breakeven.
For example, if Q is more than 10, an injection of 50 megawatts of heating power into the burning plasma will produce a fusion output of at least 500 megawatts.
Last December, the US Department of Energy (DOE) and its National Nuclear Security Administration (NNSA) announced that scientists at the Lawrence Livermore National Laboratory (LLNL) for the first time achieved a net gain of energy using laser fusion, by delivering 2.05 megajoules (MJ) of energy to a target to produce 3.15 MJ of fusion of energy output.
Prior to this, the Joint European Torus (JET), a tokamak reactor in the United Kingdom, achieved a Q value of 0.67 in 1997 by using 24 MW of thermal power to produce 16 MW of fusion power.
Fusion-fission hybrid
In a fusion-fission hybrid reactor, the high-energy neutrons produced by the fusion reactions are absorbed in a “blanket” of fissionable material, where they trigger fission reactions. The favored blanket fuels are the plentiful isotopes uranium-238 or thorium-232.
A major advantage of the hybrid reactor is that each fusion neutron can trigger several fission events, multiplying the energy released by each fusion reaction by many times. This drastically reduces the demands placed on the fusion reactor, which no longer has to produce net energy.
This makes a hybrid fusion-fission power plant in principle much easier to realize than a “pure” fusion power plant – and thus possibly deliverable much faster.
The Chinese government had included a fusion-fission hybrid project in its 863 program, a high-technology development plan launched in 1987, but terminated the project in 2000.
In 2008, Peng Xianjue from the China Academy of Engineering Physics and his team pointed out that traditional fusion-fission hybrid research had faced a bottleneck due to problems in breeding and transmutation of chemical elements.
These problems can be resolved by using a Z-pinch-driven fusion-fission hybrid reactor (Z-FFR), Peng said.
A Z-pinch, or zeta-pinch, reactor uses a gigantic pulse of electric current to generate a magnetic field that compresses the plasma.
Peng said in September 2022 that China planned to build a 50-million-ampere Z-pinch machine, which would be ready for experimental use by 2025. He said this Chengdu-based machine would be the largest in the world. A comparable machine at the Sandia National Laboratory in the US can produce only 26 million amperes. Peng said then that the country would be able to generate fusion power around 2028 and build a fusion-fission reactor for commercial use in around 2035.
It is possible that the proposed fusion-fission reactor in Jiangxi will also use Peng’s Z-pinch design although the announcement by Jiangxi Electric Group did not specify what type of fusion reactor would be used.
Nuclear weapons scientist
Peng, 82, was originally a nuclear weapons scientist before he started focusing on fusion power in the 2000s.
He graduated from the People’s Liberation Army Military Institute of Engineering, currently known as the Harbin Engineering University, in 1964. The institute was established in 1953 to allow Chinese students to learn the Soviet Union’s technologies.
Peng had contributed to the design of China’s first hydrogen bomb, which was made by Chinese physicist Yu Min and Yu’s team in 1967. Yu was honored as “the father of the Chinese hydrogen bomb” although he personally refused to accept the title.
In 1996, Peng began to focus on research related to the safety and reliability of nuclear weapons and explore the peaceful usage of nuclear explosions. In 1999, he became an academician of the Chinese Academy of Engineering.
In 2000, he started focusing on Z-pinch research after the Sandia National Laboratories had made a major breakthrough in the area in 1997.
Read: China beats the drum for faster fusion energy results
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