The concept of closed nuclear fuel cycle seems to be the most promising options for the efficient usage of the nuclear energy resources. However. it can be implemented only in fast breeder reactors of the IVth generation. which are characterized by the fast neutron spectrum. https://www.roneverhart.com/Toshiba-AL13SX-AL13SXB30EN-300GB-15K-RPM-SAS-12Gb-s-512n-128MB-2-5-Hard-Drive/