Installation of the containment dome marks a significant milestone in the construction of the second of two reactors being built in Pakistan by Chinese companies.

The dome — measuring 36 metres in diameter, 9 metres in height and weighing some 185 tonnes — was emplaced on the top of the containment building of Chashma unit 4 on 2 January. The operation took just 50 minutes to complete, China’s State Nuclear Power Technology Company (SNPTC) reported. It noted that the milestone was reached 72 days ahead of schedule.

Two 340 MWe pressurised water reactors (PWRs) are under construction at Chashma, adding to the generation already provided by Chashma 1 and 2 — 300 MWe PWRs also supplied by China. The general contractor for units 3 and 4 is China Zhongyuan Engineering. The reactor design was provided by the Shanghai Nuclear Engineering and Research Design Institute.

Construction of unit 3 officially started at the end of May 2011, and unit 4 in December 2011. The dome of unit 3 was fitted in March 2013. The new units are scheduled to begin commercial operation in December 2016 and October 2017 respectively.

Only one other power reactor operates in the country, a 125 MWe pressurised heavy water reactor at Karachi (Kanupp). All units are owned and operated by the state-owned Pakistan Atomic Energy Commission.