1. Separation-transmutation (ST)

1.1 Concept and strategy

The attractive idea of transforming the long-lived radionuclides (actinides beyond uranium and certain fission products) that pose problems in the long-term management of radioactive waste into short-lived radionuclides (or stable isotopes) dates back several decades. Their transmutation in large quantities in intense neutron fluxes is, in principle, feasible. However, this requires the radionuclides to be separated from the spent fuel. The concept of separation-transmutation (ST) thus offers a solution to all the long-term issues encountered in geological disposal (scientific, sociological, ethical), since the cause of the problems is removed. This concept has therefore been studied since the 1960s-1970s, with occasional, sometimes lengthy experiments carried...