Mandated by Andra, I am preparing a Ph.D. Thesis in Semiotics, "Robustesse sémiotique et pérennité interprétative. La vie des signes à l'épreuve du temps long" (which could be translated by "Semiotics robustness and interpretation sustainability. Subjecting signs to the test of time"). Given the dangerous nature of nuclear waste and its longevity, decisions have been made to put them into geological disposals. As a matter of fact, nuclear waste remains dangerous to humans and any other living critters for thousands of years. As it is our responsibility to keep any living critters, including humans, away from it, putting them into geological disposals enables us to seek a better solution and/or to wait for the radioactive decay to reach a normal and thus non-dangerous level.In this perspective of burial, the question of memory arises. How do we ensure that anyone who comes across such a site, in one thousand or ten thousand years, gets to know the nature of the site and its risks? Regarding to this matter, semiotics, the study of systems of signification, allows us to find an efficient and sustainable solution.