The first century...
This is the first leg of the race between the natural decay of radioactivity and the degradation of the barriers used to contain it. Packages of highly radioactive waste have been stored in concrete structures at a very great depth, in a very stable host rock selected in France. No water flows through it, or if it does, only very slowly. Everything is new. The activity of the package, which is 1000 at 5 years of age, will drop to 69 after 100 years. During the first century, the radioactivity will remain extremely high, but the barriers – still intact – will contain it.
IN2P3 et CEA