China revolutionized the energy sector: the first fusion-proof nuclear power plant is already a success

Discover how China is leading innovation in nuclear energy with a safe and efficient modular fission reactor that promises decarbonization and energy security

Disasters such as Chernobyl and Fukushima led a large part of public opinion to oppose nuclear energy, but China wants to change this situation with the first core melt-proof plant. The HTR-PM demonstrated its safety by operating at full power.

A pioneering fission reactor. Opened in December 2023 in Shidaowan, Shandong Province, the HTR-PM (High-Temperature Gas-Cooled Reactor Pebble-Bed Module) is the first small modular reactor (SMR) installed on dry land. Developed by Tsinghua University's Institute of Nuclear Technology and New Energy, it is also the second fourth-generation reactor (after the Russian BN-800) connected to the electrical and heating grid. Since its opening, it has provided thermal energy to 1.850 homes.

Characteristics of the HTR-PM and its technological innovation

The first SMR with a ball bed. The HTR-PM has two 250 MW thermal modules that drive a 210 MW electrical steam turbine. The most characteristic of this small gas-cooled modular fission reactor is that, instead of traditional fuel rods, it uses a bed of spheres. The HTR-PM is the first SMR with this design, in which the nuclear fuel is encapsulated in graphite spheres with a lower energy density that allow for more effective and safe cooling.

How HTR-PM works

Gas Refrigeration: The HTR-PM is a gas-cooled modular fission reactor using helium as the coolant. Helium is chosen for its inert properties and high heat transfer capacity.

Sphere Bed: Ao Unlike traditional reactors that use fuel rods, the HTR-PM uses a bed of spheres. Each sphere contains small nuclear fuel particles encapsulated in graphite, which allows for better heat distribution and safer operation.

High Operating Temperature: This reactor operates at higher temperatures than conventional pressurized water reactors (PWR), reaching exit gas temperatures of around 750-950°C. This allows for greater thermal efficiency and the possibility of various industrial applications beyond electricity generation.

Passive Security: One of the most notable features of the HTR-PM is its passive safety capability. In case of failure, the reactor can dissipate residual heat naturally, without the need for active cooling systems. This is demonstrated by the fact that, during tests, the reactor was able to cool itself to a stable temperature in 35 hours without external intervention. the energy

Independent Modules: The HTR-PM consists of independent modules of 250 MW thermal each, which can be combined to drive a 210 MW electrical steam turbine. This modularity allows flexibility in the construction and operation of the plant, in addition to facilitating maintenance.

Safety and innovation in nuclear energy

Meltproof. Were two security tests were carried out on both modules, each operating at a thermal power of 200 MW. During the tests, the active power supply of the small reactors was disconnected to check whether residual heat could be eliminated passively. The reactors cooled naturally to a stable temperature in 35 hours without external intervention. This is the first time that the safety of a commercial-scale fusion-proof nuclear power plant has been demonstrated.

Development of HTR-PM began in 2016. Despite a six-year delay, the full-power results are promising for fission nuclear power safety and low-cost decarbonization. The HTR-PM is an engineering feat with which China once again highlights its ability to reduce its dependence on fossil fuels. However, there is a long way to go for its global adoption, as this technology cannot be applied to existing reactors, meaning new installations will be needed to benefit from this safe design.

Image | Tsinghua University