The HTR-PM (High Temperature Gas-Cooled Reactor Pebble-bed Module) at Shidaowan (Shidao Bay) in Rongcheng, Weihai, Shandong Province became the world's first commercial pebble-bed reactor and China's first Generation IV plant to enter commercial operation on December 6, 2023, following a successful 168-hour demonstration run. The plant features two 250 MWt helium-cooled pebble-bed reactor modules driving a single 210 MWe steam turbine. Construction began December 9, 2012 (11 years). The first reactor achieved criticality September 2021, grid connection December 2021, full power December 9, 2022, and commercial operation December 2023. In August and September 2023, safety demonstration tests confirmed — for the first time at commercial scale — the inherent passive safety of pebble bed technology. A paper published in Joule (July 2024) by Tsinghua researchers confirmed the reactor can cool itself naturally without human or emergency system intervention. Owned by China Huaneng (47.5%), CNEC (32.5%), and Tsinghua INET (20%). The plant will ultimately expand to 10 units; a larger HTR-PM600 (650 MWe from six reactors) is under development.