The objective here is compatible both with the use of Pu (as a resource) in LWRs (for a limited period of time, assuming that the deployment of fast reactors will be delayed), and with the use of Pu (or Pu+Np) in FRs, while MAs are handled in dedicated reactors (ADSs, low CR critical fast reactors, etc.).

To implement this scenario, the so-called ‘double strata’ strategy can be envisaged: MA fuels (most probably with the addition of some Pu) should be transmuted in dedicated reactors (ADSs or low CR critical FRs) while the bulk of Pu (or Pu+Np) should be multi-recycled in MOX-LWRs (e. g. Ref. 26) or in FRs. The scheme for this scenario is represented in Fig. 17.5.

The main objective of this scenario is to keep the management of MAs in a separate cycle of a smaller size, independent from the fuel cycle associated with energy production, where Pu (or Pu+Np) is multi-recycled. This is an important point, since the reprocessing and the fabrication of the fuel for the dedicated transmuters is associated with very high decay heat and neutron sources, as indicated in Section 17.3.3, which can require costly measures (e. g. remote handling, long cooling times, increased shielding, etc.) to allow feasibility.

The expected reduction of radiotoxicity is close to that expected in scenario (a) above, if the chemical separation performance (e. g. losses during reprocessing) is similar in the two scenarios.