Construction of unit 4 of China’s Tianwan nuclear power plant has entered a new phase with the installation of its containment dome.

Installation of the dome was completed ahead of schedule on 26 September and marks the end of the civil construction phase at the project, China National Nuclear Corporation (CNNC) said. The project now enters the equipment installation phase.

The operation to lift the dome into place took less than two hours, using a similar lifting program used at Tianwan 3. Innovations to the lifting process have resulted in overall time savings of nearly two months compared with the similar construction stage at Tianwan units 1 and 2, CNNC said.

Tianwan 4 is the second of two AES-91 VVER-1000 units designed by Gidropress, a subsidiary of Russian state nuclear corporation Rosatom. Two similar units that have been in commercial operation at the in Jiangsu site since 2007. AtomStroyExport, another Rosatom subsidiary, is the main contractor, supplying the nuclear island. Construction work began on unit 3 in December 2012, with unit 4 following in September 2014. The units are expected to start operation in 2016 and 2017 respectively.