How the world's first fourth-generation nuclear power plant works

The world's first fourth-generation nuclear power plant, Huaneng Shandong Shidao Bay Nuclear Power Plant in eastern China's Shandong Province, went into commercial operation on December 6, 2023 and has been running well, according to officials at the plant.

The power plant has drawn global attention as it adopts High Temperature Gas-Cooled Reactor-Pebble-bed Module (HTR-PM), which is claimed to be able to steer away from a meltdown or leak of radioactive materials even in extreme conditions.

"In the past few weeks of its commercial use, our two reactors in the power unit have maintained the initial full power stable operation. They generate electricity every day with the power of 150 megawatts," said Zhang Yijin, a chief operator at the power plant.  

"The state of the unit, including the operation of various parameters are very stable. Then the electricity we generate is supplied to the Shandong power grid and distributed for use," he added.

One of the major features of the fourth-generation reactors is the nuclear fuel which is made into a small sphere shaped like a tennis ball, and each reactor has up to 430,000 of them.

"This sphere is 6 centimeters in diameter, and inside it, are 12,000 one-millimeter coated fuel particles. And inside the particles, there's a very small fuel core, and four layers of ceramic armor," said Tong Liyun, another chief operator at the plant.

"The entire ceramic armor can withstand very high temperatures, and under any working conditions, the temperature of the fuel ball will not exceed the temperature that the ceramic armor can tolerate," Tong said.

He stressed that in this way, the design ensures that radioactive materials will not leak out.

The operator said that each sphere has the energy equal to 1.5 tonnes of coal and there is no need for the usual procedure of temporarily shutting down reactors for refueling, allowing constant operation.

The operating reactors are cooled by the inert gas helium instead of water. And they also use a passive residual heat removal system which is the key assurance for the inherent safety of high-temperature gas-cooled reactors.

Construction of the power plant began in 2012. It was connected to the grid in 2021 and went into commercial operation in 2023.

It is expected to contribute to the region's electricity supply and set an example for further development of fourth-generation nuclear power plants.

In safely using nuclear energy, China is utilizing its own third-generation nuclear power technologies like "Hualong-One" and the country is making concrete steps towards more advanced technologies like the one used in Shidao Bay.