China brings world’s first fourth-generation pebble tech nuclear reactor online

China has begun commercial operations of the world’s first fourth-generation nuclear reactor, marking a major milestone in nuclear safety and low-carbon energy innovation with its High-Temperature Gas-cooled Reactor-Pebble-bed Module (HTR-PM).

The HTR-PM, located at the Shidao Bay nuclear power plant in Shandong province, represents the first successful deployment of a reactor designed to virtually eliminate the risk of a core meltdown. Chinese state media confirmed the reactor’s full commercial operation in December 2023, following a series of safety validation tests.

As reported by bne IntelliNews, China announced the development of the pebble technology last year as part of its extensive energy research programme and expanding nuclear power station fleet.

At the core of the HTR-PM’s design is TRISO fuel—uranium particles encapsulated in layers of ceramic and graphite—enabling it to withstand temperatures above 1,600°C. This allows the reactor to operate safely even in the event of a total power loss. Tests conducted in 2023 demonstrated that the reactor could cool itself through passive heat transfer mechanisms such as conduction and convection, without the need for emergency pumps or human intervention.

“This represents a major step forward in nuclear safety,” Chinese authorities stated following the test results. The reactor’s passive safety features are intended to avoid catastrophic scenarios similar to those at Fukushima and Chernobyl.

In addition to electricity generation, the HTR-PM produces high-temperature steam above 500°C, enabling applications in industrial heating and green hydrogen production. The reactor’s modular design, classified as a Small Modular Reactor (SMR), also opens the door to wider commercial deployment both in China and internationally.

Chinese nuclear experts have positioned the technology as a platform for global leadership in SMRs, a sector increasingly viewed as critical for decarbonising hard-to-electrify industries and supplementing intermittent renewable energy sources.

Despite its promise, the technology faces challenges. The graphite used in TRISO fuel contributes to long-lived radioactive waste that remains difficult to manage, and international regulatory frameworks for fourth-generation reactors are still under development.

China’s HTR-PM project is led by China Huaneng Group in collaboration with Tsinghua University and the China National Nuclear Corporation. The twin-reactor design has a combined electrical output of 210MW.

By pursuing advanced reactor designs, China aims to expand nuclear energy’s role in reaching its 2060 carbon neutrality target while reducing reliance on imported fuels.