Demonstration HTR-PM connected to grid

21 December 2021

The demonstration High Temperature Gas-Cooled Reactor - Pebble-bed Module (HTR-PM) at the Shidaowan site in Shandong province of China has been connected to the grid, the partners in the consortium building the plant have announced.

The HTR-PM site at Shidao Bay (Image: CNEA)

The plant features two small reactors that drive a single 210 MWe turbine. It is owned by a consortium led by China Huaneng (47.5%), with China National Nuclear Corporation subsidiary China Nuclear Engineering Corporation (32.5%) and Tsinghua University's Institute of Nuclear and New Energy Technology (20%), which is the research and development leader.

The first reactor reached first criticality in September and the second in November. According to China Huaneng, the connection of the first of the unit's twin reactors took place on 20 December. Steam produced by the heat from the first reactor was used to power the turbine. The first reactor will be gradually brought to full power and various tests will be carried out before the second reactor undergoes a similar process. The current power level was not announced. The dual-reactor unit is expected to be fully operational in mid-2022, the company said.

"From this moment on, the electricity generated from the Shidaowan nuclear power plant will be dispatched by the state to deliver daily electricity to thousands of households," Tsinghua University said.

High-temperature gas-cooled reactors use graphite as a moderator and helium as a coolant, with uranium fuel in the form of 6 cm-diameter 'pebbles'. 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 - far higher than the temperatures that would be encountered even in extreme accident situations, according to the China Nuclear Energy Association (CNEA).

The HTR-PM follows on from China's HTR-10, a 10 MWt 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. Beyond the HTR-PM, China proposes a scaled-up version - HTR-PM600 - with one turbine rated at 650 MWe driven by six reactor modules.

Researched and written by World Nuclear News