The ocean may hold an enormous reserve of nuclear fuel that has remained largely out of reach because uranium is present in seawater only in tiny concentrations.Now, Chinese researchers say they have developed a new material that can capture uranium from natural seawater at more than eight times a benchmark set by the US Department of Energy (DOE).The material, called PhosCage, was developed by scientists at the Qingdao Institute of Bioenergy and Bioprocess Technology under the Chinese Academy of Sciences.In tests using real seawater, it recovered as much as 50.4 milligrams of uranium for every gram of material, compared with…