Rock Solid?

It seems that granite has 'self-sealing' properties, in its crystalline structure, that can keep fluids in place for 'hundreds of thousands of years'  (https://www.theguardian.com/science/2020/jun/02/terrawatch-could-granite-solve-the-hard-problem-of-nuclear-waste-storage). It has, consequently, been suggested that the rock may be a 'safe' place to store dangerous radioactive waste or even excess carbon dioxide (hopefully, not in scenic, well-visited tourist attractions).