Chinese nuclear authorities say their researchers have discovered rich uranium deposits deep below the Earth, in what they are calling a breakthrough for the country’s national security. Huge, industrial-grade deposits were found at depths previously thought impossible, increasing China’s estimated total reserve 10-fold to more than two million tonnes – putting China on a par with Australia, one of the world’s most uranium-rich countries – according to scientists involved in the project. Using some of the world’s most advanced technology and equipment, the geologists increased the exploration depth to 3,000 metres (nearly 10,000 feet) – six times deeper than most of the country’s uranium mines. “This world-leading project is a major breakthrough for our country,” said the China National Nuclear Corporation on its WeChat social media account on Tuesday. China’s need for uranium has been expanding , with its nuclear power supply increasing faster than any country in the world, with seven or eight new reactors built each year. Uranium also plays a dominant role in weapons production and the Chinese military’s nuclear stockpile has expanded significantly in recent years, according to some assessments of available evidence, as political tensions have increased with the US and its allies. But most uranium mines in China are small in scale with poor ore quality, and more than 70 per cent of its supply comes from countries such as Kazakhstan, Canada and Australia. This heavy reliance on overseas supply has unnerved Beijing as a security risk. Li Ziying, director of Beijing Research Institute of Uranium Geology, said the discoveries challenged mainstream theories on uranium deposit formation. It is generally believed the radioactive element only concentrates in a shallow, geophysically stable area. But some of the largest uranium deposits found in southern China in recent years are located more than 1,500 metres below the surface. And these regions have experienced violent tectonic movements that, according to previous theories, would have made the long and sophisticated process of uranium ore formation impossible. According to the Chinese nuclear authorities, Li and his colleagues found uranium could rise straight from the mantle and get trapped in small “hotspots” several thousand metres below ground during some massive tectonic collisions. In an interview with Science and Technology Daily, Li said the difficulty was that there is usually only a small hint on the surface of a deep uranium deposit. “Locating it is as challenging as finding a compact disc over an area of 10,000 sq km (3,860 miles).” Over the past decade, Chinese researchers have developed cutting-edge technology and equipment to aid the hunt for deep uranium, according to a paper published last year by Li’s team in the domestic peer-reviewed journal Bulletin of Mineralogy, Petrology and Geochemistry. This includes an airborne, ultra-sensitive remote sensor which allows scientists to detect a tiny trace of heat produced by the radioactive ore with unprecedented precision over a wide area. The Chinese researchers also developed a drilling machine with a special bore head to obtain samples from deep areas more efficiently than ever before, while speeding up data analysis using artificial intelligence technology. China aims to expand use of nuclear power amid threat of energy crisis The discovery will not immediately change China’s dependence on imported uranium because of the numerous cost and engineering challenges of extracting the deposits, according to a Beijing-based researcher studying nuclear fuel, who asked not to be named. “But in the long term it will be likely to have a profound impact on China’s position in the global market,” the researcher said. Publicly available information shows China has been exploring and buying uranium mines in Africa, the Middle East and Eastern Europe in recent years. The Chinese government has also invested heavily in development of powerful filtration materials that can extract uranium from seawater. To improve fuel efficiency, Chinese nuclear authorities plan to build several nuclear waste recycling facilities using various technologies, including a particle accelerator. And in Wuwei, in the northwestern province of Gansu, China is building an experimental molten salt reactor using thorium , a new type of nuclear fuel which China has in abundant supply.