The No. 1 unit at the China General Nuclear Power Group's Ningde Nuclear Power Plant recently completed its ninth major overhaul and was successfully reconnected to the grid for power generation. The domestically developed nuclear steam turbine control and protection system (GRE/GSE), jointly created by Dongfang Electric Corporation and China General Nuclear Power Group, has demonstrated stable operation and excellent performance. This marks the first time an in-service nuclear power unit in China has achieved localization of the GRE/GSE system, breaking foreign technological monopolies and equipping the nation's nuclear power units with a "domestic brain" for safe, stable, and economical operation.
The nuclear steam turbine control and protection system is regarded as the "nerve center" of the nuclear steam turbine. It regulates critical parameters such as turbine speed, power, and pressure, and can quickly trigger protective actions under abnormal conditions, making it the most vital system for ensuring the operation of nuclear steam turbines. For a long time, core technologies for these systems in nuclear power projects were monopolized by foreign suppliers.
To advance the high-quality development of China's nuclear power industry, Dongfang Electric Corporation established a dedicated research team years ago and fully launched R&D efforts aimed at replacing imported turbine control and protection systems in operational nuclear plants with domestic alternatives. The team successively overcame a series of core technical challenges—including system architecture, logic algorithms, reactor-turbine interfaces, transient control, and simulation verification—achieving independent control over key technologies.
The newly applied domestic nuclear steam turbine control and protection system features a dual-redundant configuration for the GRE and a triple-redundant architecture (SIL3) for the GSE. Multiple protective circuits serve as backups for each other, ensuring that a single fault does not affect protective functions, with system availability exceeding 99.99%. A full-process simulation platform was established, enabling mastery of core transient control algorithms and ensuring a successful startup of the unit on the first attempt.
Adhering to the principle of consistency in interfaces, cables, and communications, the retrofit required minimal on-site modifications. In collaboration with Ningde Nuclear Power Plant, simulation and implementation rehearsals were conducted, compressing the on-site installation and debugging period to under 30 days. By adopting a domestic hardware platform, issues such as discontinued sales of imported equipment, high spare part costs, and slow service response were resolved, significantly reducing operation and maintenance costs and securing the supply chain.
The successful retrofit at Ningde Nuclear Power Plant sets an industry benchmark for the localization of GRE/GSE systems in China's in-service nuclear power units, strengthening the nation's energy security barrier. Moving forward, Dongfang Electric will continue to leverage sophisticated technology, refined products, attentive service, and lean management to achieve independent control over key core equipment, injecting strong momentum into the high-quality development of China's nuclear power sector.