The nuclear heating project based on China’s demonstration High Temperature Gas-Cooled Reactor-Pebble-bed Module (HTR-PM) at the Shidaowan site in Shandong province has been connected to the heating grid and put into operation, according to China Huaneng.

The project is a collaborative effort with Tsinghua University responsible for research and development and main components and systems design. China Huaneng Group is the owner and operator of the plant, and China National Nuclear Corporation is the engineering, procurement, and construction contractor and fuel manufacturer.

The HTR-PM features two 250 MWt reactors that drive a single 210 MWe steam turbine. It uses helium as coolant and graphite moderator. Each reactor is loaded with more than 245,000 spherical fuel elements, each 60mm in diameter and containing 7g of fuel enriched to 8.5%. Each pebble has an outer layer of graphite and contains some 12,000 four-layer ceramic-coated fuel particles dispersed in a matrix of graphite powder. The fuel has high inherent safety characteristics, and has been shown to remain intact and to continue to contain radioactivity at temperatures up to 1620°C, China Nuclear Energy Association reported.

The project uses high-temperature steam from the HTR-PM to heat water in a heat exchanger. This high-temperature water flows to the heat exchange station in the municipal and power station energy areas and undergoes secondary heat exchange to provide residential heating. The project will add an additional 190,000 square metres of heating area, which can meet the needs of 1850 households. It can replace 3,700 tonnes of coal every heating season and reduce carbon dioxide emissions by 6,700 tonnes.

China Huaneng said this marks "the first time that a fourth-generation nuclear energy heating system has realised heating for urban residents, and a breakthrough in the comprehensive utilisation of fourth-generation nuclear energy”.

First concrete for the demonstration project was poured on December 2012, and the operating permit was granted in August 2021 followed by grid connection some three months later. The plant was declared to be in commercial operation in December 2023.

The HTR-PM is based on the HTR-10 high-temperature gas-cooled experimental reactor at Tsinghua University's Institute of Nuclear & New Energy Technology, which started up in 2000 and reached full power in 2003. China is now developing a larger HTR-PM600 – with one turbine rated at 650 MWe driven by six reactor modules.

Image: The HTR-PM demonstration project at Shidaowan (courtesy of China Huaneng)