China National Nuclear Corporation’s (CNNC's) test platform for uranium extraction from seawater has been put into operation and opened to the public in Hainan Province. The test platform, in the South China Sea, is able to carry out material verification and amplification experiments under real ocean conditions. It has a total area of about 670 square metres.
It is estimated that proven land-based uranium resources, at the current consumption rate, will only last for about 100 years. However, seawater contains approximately 4.5bn tonnes of uranium resources, which is around 1,000 times larger than land reserves. For several decades, countries have been looking to develop large-scale technologies for extracting uranium from seawater. While notable research results have emerged in recent years due to the rapid advancement of nuclear power, cost-effective engineering solutions for seawater uranium extraction remain limited, with most research outcomes still confined to laboratory settings.
In November 2019, CNNC initiated an alliance for technological innovation in seawater uranium extraction, collaborating with 14 domestic research institutes to accelerate engineering applications for seawater uranium extraction technology. This is a difficult task due to the low concentration of uranium in seawater.
Naturally occurring uranium in seawater is at a concentration of about 0.003 parts per million (ppm) while the average abundance of uranium in the Earth's crust is about 2.7ppm and ore grades are many times greater than that. The total uranium resources in land-based ores recoverable at costs of up to $130 per kilogram are around 3.7m tonnes.
The key to extracting uranium from seawater depends to a large extent on the absorption material. The adsorption capacity of materials can be significantly impacted by marine pollution, climate conditions, and ocean currents.
The choice of adsorption materials and the cost of marine engineering are therefore critical factors influencing the economic viability of seawater uranium extraction. Field tests are essential. CNNC’s platform is able to carry out material verification and amplification experiments under real ocean conditions, and will also be open for use by alliance members.
The research and development plan outlined by the seawater uranium extraction technology alliance in China aims to achieve international leadership in this field by 2035. By 2050, their objective is to realise the engineering development and utilisation of seawater uranium resources, culminating in the establishment of a large-scale seawater uranium extraction plant.
CNNC said the test platform will form a "two centres, one platform" seawater uranium extraction scientific research base together with a research and test centre and an international exchange centre. CNNC Deputy General Manager Cao Shudong told the 2023 Seawater Uranium Extraction Technology Innovation Alliance Council and Academic Exchange Conference that exploring unconventional uranium resource development technologies and promoting land and sea uranium resources are strategic choices to ensure the sustainable and steady development of China's nuclear energy industry.
Image: The test platform for extracting uranium from seawater (courtesy of CNNC)