In this episode we cover the final storage of nuclear waste in underground facilities. We start out with a conversation about the basic process and the chemistry and physics of nuclear waste with Gareth Law, a professor of radiochemistry at the university of Helsinki. We then discuss geological issues with Heini Reijonen of the Geological Survey of Finland. Our third conversation is about the Onkalo storage facility in Finland with Sophie Haapalehto, who works for Posiva, the operator of the site.