Designing and building the first land-based SMR


The construction of ACP100 nuclear power units can form the basis for green development in this pilot zone and contribute to achieving Hainan’s clean development goals.

The ACP100 is a third-generation SMR design that maximizes the use of mature technologies and equipment. The reactor has a thermal power capacity of 385 MWt and a net electric output of up to 126 MWe.

The first unit is being built at Changjiang in Hainan province, where two CNP-600 reactors are already in operation and two 1100 MWe Hualong One reactors are under construction. Once completed, the Changjiang ACP100 reactor will be capable of producing 1 billion kilowatt-hours of electricity annually, enough to meet the needs of 526,000 households.

The project at Changjiang involves a joint venture of three main companies: CNNC subsidiary China National Nuclear Power as owner and operator; the Nuclear Power Institute of China (NPIC) as the reactor designer; and China Nuclear Power Engineering Group being responsible for plant construction.

When first concrete was poured on 13 July 2021, the ACP100 demonstration model became the first land-based commercial SMR to start construction in the world.

The containment vessel bottom head - which will support the steel containment shell - was assembled on-site from50 pre-fabricated steel plates. The assembled component was hoisted into place by crane onto the plant's concrete foundation plate on 24 October 2021.

The lower section of the containment shell - some 15 metres in height and weighing about 450 tonnes - was lowered into place upon the vessel bottom head on 26 February this year, 46 days ahead of schedule. The total construction period is scheduled for 58 months, and it is currently on schedule.

China National Nuclear Corporation (CNNC) started R&D work on the ACP100 in 2010 and the design passed the IAEA Generic Reactor Safety Review on 22 April 2016.

In October 2017, the Chinese Nuclear Society recognized the ACP100 technology to be one of “China’s Top 10 Advances in Nuclear Technology in 2015-2017”.

As an innovative SMR design, the ACP100 design has passive safety features that are expected to handle extreme environmental conditions and multiple failures without any significant radioactive release.

The ACP100 also features integrated reactor design technology, modular design and fabrication, and integral steam generator with the reactor coolant pump mounted on the pressure vessel nozzle. All these technologies provide high inherent safety to prevent large-scale loss of coolant accidents (LOCAs).

These design innovations allow the reactor manufacturing, transport and site installation processes – and the economics of the ACP100 – to be optimized.


Qu Yong, Deputy Chief Engineer, CNNC Hainan Nuclear Power Company

What consideration led to choose ACP100 design and Changjiang site to implement it?

In recent years, Chinese authorities have promoted the construction of the Hainan Free Trade Port. They are
committed to developing Hainan island into a national ecological civilization pilot zone and a key gateway to the
Pacific and Indian Oceans. 

The construction of ACP100 nuclear power units can form the basis for green development in this pilot zone and contribute to achieving Hainan’s clean energy development goals.

Besides electricity generation, the ACP100 can serve many other purposes such as seawater desalination, district heating (or cooling) and process heat supply. It is also suited to various locations and  application scenarios, including small and medium sized power grids, industrial parks, islands and as a  edicated power source for high energy-consuming enterprises.

The ACP100 demonstration project will help Hainan to become a base for the promotion of China’s  advanced commercial small modular reactor technology to the world. With two CNP-600 units in operation and  further two under construction at the Hainan site, the companies working at the Changjiang nuclear power plant  have accumulated a wealth of experience in constructing,managing and operating nuclear power projects. The
ACP100 demonstration project at the Changjiang site can make full use of the available resources to improve the economics of the project as much as possible. 

Will the traditional supply chains be able to easily adapt to the new requirements specific to SMR?

Compared with traditional equipment supply, modular equipment relies on detailed design, advance orders, factory prefabrication, as well as the transport, lifting and installation of large modules. In addition,  parallel operations offsite and onsite have to be carried out, reducing the time for onsite construction. Much of the fabrication work is carried out in the manufacturing plant, where it is easier to control the temperature, humidity and cleanliness of the working environment, while avoiding onsite typhoons, rainstorms and dust. 

For example, after the steam generator is manufactured, it has to be transported to the pressure vessel manufacturing plant to be incorporated into the reactor. After the welding is completed, the integral  reactor will be transported to the site; at the same time the prefabricated steel containment shell plate has to be transported to the site for assembly. After the module equipment arrives onsite, only simple lifting operations are required to realize the installation of the entire equipment or system, which greatly reduces the construction period of the project. 

Modular equipment has precise manufacturing and project management requirements, and some large  modules pose new challenges in terms of transport and hoisting. In general, the ACP100 supply chain builds on existing international and domestic modular equipment supply, with improved quality of modules and reduction of module manufacturing costs.