Hualong One Unit 3 of the Karachi nuclear power plant (K-3) in Pakistan has successfully conducted a cold hydrostatic test of its primary circuit, another major step forward for overseas Hualong One projects, after the first overseas Hualong One nuclear unit was connected to the grid. It also marked the moment that the K-3 unit entered the commissioning stage, following its installation.

The successful test was witnessed by the Pakistan Nuclear Regulatory Authority (PNRA) and the Pakistan Atomic Energy Commission (PAEC).

Cold functional testing is a comprehensive test of whether the key components and systems in the nuclear island are properly installed and ready to operate in a cold condition. Its main purpose is to verify the security of the primary circuit and components and the function of relevant components and systems. It is the first comprehensive test of the whole reactor's performance.

Hualong One is China's third-generation nuclear power technology with full intellectual property rights. With a design life of 60 years, the Hualong One reactor adopts a 177-core design that replenishes the fuel every 18 months and has a utilization rate of over 90 percent. It innovatively uses a combination of "passive and active" safety systems with double containment, which meets the highest international safety standards. Hualong One is one of the most widely-accepted third-generation nuclear power reactors in the current nuclear power market.

Units 2 and 3 of the Karachi nuclear power plant are contracted to China National Nuclear Corporation (CNNC)'s China Zhongyuan Engineering Corporation (CZEC).