Progress in the pyrochemical processing of spent nuclear fuels

Following the electroreduction of uranium dioxide to uranium in LiCl–KCl eutectic in situ using synchrotron radiation

“…Molten salt electrolytes have been proven to be a suitable media for the electrochemical separation of actinides; many studies have http shown the ability to anodically titrate nuclear species into molten salts [4][5][6][7][8][9], to electroreduce/electrodeposit nuclear species from molten salts [5,[10][11][12][13][14][15] and the ability to scale-up molten salt separation processes to the kg scale [16][17][18]. Inman et al showed the electrochemical reversibility of U 3+ |U system in LKE [5] and Sakamura et al have shown the 4-electron transfer electroreduction process of UO 2 to U in CaCl 2 and LiCl salts [19].…”

A US perspective on fast reactor fuel fabrication technology and experience part I: metal fuels and assembly design

“…Molten salt electrochemical reprocessing is a currently used pyrometallurgical process that dissolves (in molten salt) and separates spent fuel from the undissolved cladding. The dissolved spent fuel is then electrolytically separated from the bulk of the fission products; the fuel products are deposited at the cathode, while most of the fission products remain in the salt [40,42]. Electrorefining produces a product that performs satisfactorily in a nuclear reactor, but it is also highly radioactive; thus, it is selfprotecting and minimizes proliferation concerns [43].…”

Investigating microstructural evolution during the electroreduction of UO2 to U in LiCl-KCl eutectic using focused ion beam tomography

“…Research into the reprocessing of spent nuclear fuel using molten salt media has become increasingly popular as an alternative to the PUREX process [1][2][3]. Spent oxide fuel must first be reduced to the metallic form prior to electrorefining.…”

“…One technique of achieving this is via the addition of cadmium chloride to a LiCl-KCl eutectic (LKE) salt which serves to oxidise metallic spent fuel, resulting in U 3+ and Pu 3+ species in solution. These species are then recovered electrochemically at solid and liquid electrodes to acquire uranium and plutonium metals respectively [2,4,5]. The reduction of spent fuel oxides may also be done chemically via the reaction of dissolved lithium in LiCl at 650°C, as described by Karell and Gourishankar [6,7].…”