Fuel fabrication and reprocessing for nuclear fuel cycle with inherent safety demands

Abstract

The strategies adopted in Russia for a closed nuclear fuel cycle with fast reactors (FR), selection of fuel type and recycling technologies of spent nuclear fuel (SNF) are discussed. It is shown that one of the possible technological solutions for the closing of a fuel cycle could be the combination of pyroelectrochemical and hydrometallurgical methods of recycling of SNF. This combined scheme allows: recycling of SNF from FR with high burn-up and short cooling time; decreasing the volume of stored SNF and the amount of plutonium in a closed fuel cycle in FR; recycling of any type of SNF from FR; obtaining the high pure end uranium-plutonium-neptunium end-product for fuel refabrication using pellet technology.

Nitride fuel for Gen IV nuclear power systems

“…The practical experience with irradiated nitride fuels is however rather limited. A large quantity of spent (~ 80 GWd/ton) (U,Pu)N fuel was successfully reprocessed by a somewhat modified acid dissolution and liquid extraction process, in which dissolution was assisted by a small addition of fluoride [ 72 ]. In particular, actinide nitride pellets with a large admixture of zirconium nitride have been shown to be exceptionally difficult to dissolve without addition of fluoride ions or hydrofluoric acid HF (which too become equivalent in the nitric acid environment) [ 71 ].…”

“…If on the other hand natural nitrogen (> 99% 14 N) is used in the fuel manufacture, the additional issue (besides the neutron economy penalty) of 14 C production must be dealt with. The feasibility of 14 C capture has been demonstrated [ 72 ], and 14 C is already separated and stored in industrial-scale reprocessing [ 75 ]. Yet this results in an additional long-lived waste fraction that can be avoided if 15 N is used.…”