Mega cooling tower completed at Chinese unit

The final concrete for the circular foundation of the tower was poured in November 2023. The foundation is more than 10 metres wide and more than 2 metres thick. A total volume of about 15,900 cubic metres of concrete was used to form the foundation.

The cooling tower now has a height of 218.7 metres and a diameter at its base of about 175 metres. A total of 137,400 cubic metres of concrete was used in the tower's construction. The water spraying area of the tower is 20,000 square metres. It mainly consists of a foundation, inclined pillars, tower tube, and inlet. It consists of a central water shaft, water distribution system, heat exchange filler, water collection system, main water collection tank, and water eliminator.

SPIC said that, with the main structure now complete, the installation of internal components of the tower is set to begin.

"The successful completion of the cooling tower has accumulated valuable experience for the design and construction of ultra-large seawater cooling towers in China's nuclear power field," SPIC said.

The company noted that, unlike the 'once-through cooling' model commonly used in traditional nuclear power plants, the 'secondary circulation cooling technology' used in the cooling tower of Lianjiang 1 represents "a new technological breakthrough". It said this technology replaces direct seawater extraction and discharge with the reuse of cooling water. Using the atmosphere as the ultimate heat sink, it recycles cooling water through air-water heat exchange.

"This significantly reduces water intake, greatly minimising the operational risk of marine organism infestation at the nuclear power plant and enhancing the safety and stability of power supply," SPIC said. "Furthermore, water discharge is significantly reduced to one-fortieth of that of traditional nuclear power plants, and the discharge temperature approaches that of natural seawater, further enhancing the environmental friendliness of the nuclear power project."

The first phase of the Lianjiang nuclear power plant project - the first coastal nuclear power project developed and constructed by SPIC in Guangdong - will comprise two CAP1000 units. The site is eventually expected to house six such reactors. It is the first nuclear power plant in China to adopt seawater secondary circulation cooling technology, and is the first to develop and use a super-large cooling tower.

The construction of the first two 1250 MWe CAP1000 reactors - the Chinese version of the Westinghouse AP1000 - at the Lianjiang site was approved by China's State Council in September 2022. Excavation works for the units began in the same month. The first safety-related concrete for the nuclear island of unit 1 was poured in September 2023 and that of unit 2 in April last year.

Lianjiang unit 1 is expected to be completed and put into operation in 2028.