ABSTRACT
As already stressed, the production of transuranic or transplutonic elements could be two to three orders of magnitude smaller in reactors using the Th-U cycle than in present-day PWR reactors. When the choice was made in favour of the plutonium economy, considerations about the level of nuclear waste production were not considered a top priority. This is one of the reasons why the Th-U cycle was disregarded. Nowadays it is clear that this cycle would offer great advantages by a considerable reduction of incineration needs. In this context, hybrid reactors, with their favourable neutron balance, might be of special interest.
