Removal of 90Sr from highly Na+-rich liquid nuclear waste with a layered vanadosilicate
Capture of trace amounts (parts per trillion or ppt level) of 90Sr from highly Na+-rich (5 M or 115 000 parts per million) liquid wastes produced from reprocessing of spent nuclear fuel rods is crucial for continuous operation of nuclear power plants. However, no sorbents have shown such abilities. We now report that a novel layered vanadosilicate, SGU-7, with the unit cell parameters of a = 23.58 Å, b = 30.04 Å, c = 12.31 Å, β = 100.2°, and space group of P121/a1, can effectively capture 90Sr from a 5 M Na+ solution containing 6.2 ppt of 90Sr. It also effectively captures 1-ppb level 226Ra from 2 M NaCl solution, and Cs+ and Sr2+ from groundwater, demonstrating that it can be immediately used to remedy groundwater and soil contaminated with 226Ra, 90Sr, and 137Cs.