Nuclear power generates 12% of Spain's total energy and produces radioactive waste since 1969. Nuclear waste strongly emits radiation and contains substances like plutonium-240 and neptunium-237 that have extremely long half-lives of 6,600 years and 2.13 million years respectively, making the waste dangerous for thousands of years. The document argues that developing renewable energy and improving energy efficiency is not enough and that more needs to be done with the radioactive waste generated by nuclear power.