Membrane methods exhibit great potential for application in radioactive liquid waste treatment. In this work, we prepared a reduced graphene oxide using the amino-hydrothermal method (AH-rGO) that exhibited effective rejection rates of 99.9% for CoCl₂, ZnCl₂, NiCl₂, and radionuclide ⁶⁰Co solutions with an ultrahigh water permeance of >71.9 L m⁻² h⁻¹ bar⁻¹. The thickness of the AH-rGO membranes affects the water permeance, as the membrane with a thickness of ≈250 nm has the highest water permeance of up to 125.1 L m⁻² h⁻¹ bar⁻¹ with the corresponding rejection rate of 86.8%. Importantly, this is the most permeable membrane with a satisfactory level of the rejection rate for typical radioactive ions of Co²⁺, Zn²⁺, and Ni²⁺. Moreover, the AH-rGO membranes presented excellent stability. These findings demonstrate the potential of reduced graphene oxide (rGO) membranes for radioactive liquid waste treatment.