Reprocessing of spent nuclear fuel is an important step in closing the nuclear fuel chain. Recovered uranium and plutonium can be used in mixed-oxide (MOX) fuel and re-enters the fuel cycle in the current generation of light water reactors. Advanced reprocessing strategies are being studied to further separate the minor actinides (MAs) to reduce the long-term radiotoxicity of the raffinate. Over the last few years, ionic liquids (ILs) have found their way into spent nuclear fuel reprocessing research. ILs are frequently regarded as safer alternatives to organic solvents in solvent extraction processes because of their negligible vapour pressure, low flammability and high thermal and chemical stability. However, no universally applicable method exists to condition radioactive IL waste streams for safe disposal so far. Conventional incineration is often impossible because of the formation of harmful compounds. Hence, solidification followed by super-compaction and permanent storage is the only remaining option.