Comment Re:Long life (Score 4, Informative) 86
Don't conflate "forces a burial site to last 100,000 years" with the half-life.
I'd assume the majority of the elements' half-lives are much shorter than 100,000 years, so that they will have dropped in population enough after 100,000 years for the waste to be considered 'safe'.
Wikipedia: Radioactive waste gives a run down of the isotopes of concern and their half-lives.