The concrete foundation slab has been completed for the conventional island of the ACP100 multi-purpose small modular reactor (SMR) demonstration project (Longlong One) at China’s Changjiang NPP on the island province of Hainan China, National Nuclear Corporation (CNNC) announced on 3 May. Construction of the slab – 60 long and 53 metres wide – lasted 169 days and it was completed 10 days ahead of schedule.

CNNC said it containing some 1300 tonnes of steel reinforcement and was built in nine sections. The thickness of the foundation of the steam turbine base is 2.5 metres, while the thickness of the other sections ranges between one and four metres.

Construction of the 125 MWe ACP100 integrated pressurised water reactor   began in July 2021. The reactor. under development since 2010, is designed for electricity production, heating, steam production or seawater desalination. The preliminary design was completed in 2014. The major components of the primary coolant circuit are installed within the reactor pressure vessel (RPV). In 2016, the design became the first SMR to pass a safety review by the International Atomic Energy Agency. The preliminary safety analysis report for a single unit Changjiang demonstration plant was approved in April 2020. Construction time is expected to be 58 months.

The project involves a joint venture of three main companies: CNNC subsidiary China National Nuclear Power as owner and operator; the Nuclear Power Institute of China as the reactor designer; and China Nuclear Power Engineering Group being responsible for plant construction. For the demonstration plant, the RPV is being supplied by Shanghai Boiler Works Limited, the steam generators by a CNNC subsidiary and other reactor internals by Dongfang Electric Corporation.

The Changjiang site hosts two operating CNP600 pressurised water reactors with two Hualong One units also under construction and due to enter commercial operation by the end of 2026.