A digital control system (DCS) is being installed at the ACP2100 small modular reactor (SMR) demonstration project, also known as the Linglong One, at the Changjiang site in Hainan province. China National Nuclear Corporation (CNNC) said the first DCS has been put in place allowing installation and debugging work to begin.

The DCS comprises two Chinese-designed platforms – the Dragon Scale platform (safety level) and Dragon Fin platform (non-safety level). The Dragon Scale platform ensures reactor safety control under various working conditions. Dragon Fin controls operation and management and ensures the efficient and economical operation of the NPP. Together they control hundreds of systems, some 10,000 equipment operations and various operating conditions.

The Dragon Fin platform cabinet is a plant-wide non-safety control system specially developed by CNNC for large nuclear facilities. It is based on the nuclear power instrumentation and control experience and key technologies accumulated by CNNC over the years. It incorporates the latest advanced technologies such as data collection, process control, large-scale networking and information management to meet the requirements of high reliability and safety of nuclear facilities.

CNNC said: "The smooth introduction of the first DCS cabinet in Linglong One, the world's first land-based commercial small modular reactor, marks the transition of DCS to the on-site installation stage, laying the foundation for subsequent work such as the availability of the main control room."

CNNC began development of the Linglong One in 2010, and it was the first SMR project to pass an independent safety assessment by International Atomic Energy Agency experts in 2016. Its integrated pressurised water reactor (PWR) design was completed in 2014 and it was identified as a key project in China's 12th Five-Year Plan. The design, which has 57 fuel assemblies and integral steam generators, was developed from the larger ACP1000 PWR. It incorporates passive safety features and could be installed underground.

CNNC announced in launch of a project to construct an ACP100 reactor at Changjiang in 2019. The State Council approved the ACP100 Science & Technology Demonstration Project in 2021 and first concrete was poured in July that year. The lower section of the containment shell of was hoisted into place on in February 2022 and the last tank of concrete for the nuclear island's underground retaining walls was poured the following August.

The project is owned by CNNC Hainan Nuclear Power Company, a subsidiary of China National Nuclear Power (CNNP – itself a subsidiary of CNNC). The projected start-up date is May 2025. Once completed, the project will produce enough power to meet the needs of 526,000 households. The reactor is designed for electricity production, heating, steam production or seawater desalination. There are already two operating CNP600 power units at the Changjiang site, and construction of the two Hualong One power units began in March and December 2021 for operation by the end of 2026.

Image courtesy of CNNC