Rapid construction of Chinese SMR containment shell continues

The steel containment of the ACP100 - also referred to as the Linglong One - is composed of a top head, an upper cylinder, a lower cylinder and a bottom head. It carries the integrity and sealing functions of the reactor building and is an important safety barrier for the reactor.

The containment vessel bottom head - which will support the steel containment shell - was assembled on-site from 50 pre-fabricated steel plates. The assembled component was hoisted into place by crane onto the plant's concrete foundation plate on 24 October last year. 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.

China National Nuclear Corporation (CNNC) has now announced that the upper cylinder of the containment shell - about 15 metres in height and weighing about 720 tonnes - was placed upon the lower cylinder on 6 July.

"The site adopts the advanced construction mode of factory manufacturing and modular construction, which optimises the site construction logic, effectively reduces the site construction period, and saves the time for the reactor," CNNC said.

CNNC announced in July 2019 the launch of a project to construct an ACP100 reactor at Changjiang. The site is already home to two operating CNP600 PWRs, while the construction of the two Hualong One units began in March and December last year. Both those units are due to enter commercial operation by the end of 2026.

Construction of the multi-purpose 125 MWe pressurised water reactor (PWR) officially started on 13 July 2021, with a planned total construction period of 58 months.

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 reactor is designed for electricity production, heating, steam production or seawater desalination.

Under development since 2010, the ACP100 integrated PWR's preliminary design was completed in 2014. The major components of its primary coolant circuit are installed within the reactor pressure vessel. In 2016, the design became the first SMR to pass a safety review by the International Atomic Energy Agency.

"The construction of the Linglong One project is progressing smoothly, marking that China is at the forefront of the world in the development and utilisation of small modular pressurised water reactors," CNNC said.