With transmutation and the option for recycling it altogether, waste is not an issue. Only the low fission parts of the spent fuel is low-grade active for longer than 1000 years, but this is such a low level of radiation, it is comparable to natural uranium formations and not an issue. The high radiation part of the fuel has lost the dangerous level of radiation in less than 1000 years and can be recycled before. The arenic compounds and other substances as byproduct of copper etc production for the mass of renewables have a much longer shelf life of toxitity. Also, you need more of them.