The objective here is the management of spent fuel inventories, as a legacy of previous operation of nuclear power plants, both for a strategy of continuation of nuclear energy, based only on LWR reactors, and for one of nuclear energy phase-out. As for reprocessing, a ‘grouped TRU recovery’ (i. e. TRU recovery without separation of Pu from MAs) is likely. As dedicated reactors, both ADSs and low CR critical FRs can be envisaged, with a MA/Pu concentration ratio -0.1 in the fuel.

The scheme of this scenario is presented in Fig. 17.6.

In the phase-out case, the scenario would lead to a reduced repository burden and a low final inventory of TRUs. If implemented by a country in isolation, however, this strategy would require a substantial deployment of new installations (fuel reprocessing and fabrication, ADS, etc.). Moreover, after ~100 years of operation ~20% of the initial TRU inventory (i. e. the last transmuter inventories) would be left in the wastes.27 A better approach would be to conceive ‘regional’ P&T scenarios,28 with fuel cycle facilities shared among different countries, possibly with different strategies in terms of future nuclear energy utilization.