Separation of Actinides from Rare Earth Elements by Electrorefining in LiCl-KCl Eutectic Salt.

Abstract

A pyrometallurgical partitioning technology to recover actinides from high level radioactive wastes is being developed. In the process, actinides are separated from fission products by electrorefining in molten chloride systems. It is expected that REs (rare earth elements), main components of fission products are hardly separated from actinides. In order to estimate separation factors, electrorefining experiments to recover actinides from LiCl-KC1 eutectic salt containing actinide (U, Np, Pu and Am) and RE (Y, La, Ce, Nd and Gd) chlorides were carried out at 45OoC. Actinides were removed from a liquid cadmium anode and recovered as metal on a solid cathode. Typical cathode deposits were rough in appearance and contained 70-90wt% adhering salt. The current efficiency was low because some of the deposit occasionally fell from the cathode. It is shown that uranium, neptunium and plutonium are relatively easily separated from REs and that americium is accompanied by some of REs.

Modeling Solute Thermokinetics in LiCI-KCI Molten Salt for Nuclear Waste Separation

“…For more sampling of Sr in the LiCl-KCl, longer simulation (400ps) was conducted than the FPMD (36ps). The comparison of Sr-X RDFs between IPMD (LAMMPS) and FPMD (VASP) are shown in We should note that, as has also been found by other studies, the p [4] and p [5] parameters may be sensitive to the concentration of LiCl-KCl molten salt as well as the concentration of the solutes and the sizes of the simulation cells.…”

“…Originally developed for spent metallic fuel from the fast reactors, pyro processes can be also used for spent fuel from the current light water reactors (LWRs) using electroreduction, electrorefining, and pyropartitioning; they are also regarded to be more proliferation-resistant than the traditional wet processes. Molten mixtures of LiCl and KCl are strong candidates for pyrometallurgical recycling process [2][3][4][5][6][7] as well as in other industrial chemical processes [8]. In particular, an eutectic mixture of LiCl-KCl is attractive as a solvent because of its lower melting point (626K) relative to that of the constituent salts (883K for LiCl and 1043K for KCl).…”

“…Eutectic LiCl-KCl (58% LiCl, 42% KCl), is a common molten salt used in electrorefining of spent nuclear fuel to separate actinides and other fission products [80][81][82][83]. While the basic salt properties are known and can be used to validate our approaches, the thermokinetics of solutes within LiCl-KCl are not well characterized and can be a subject of future modeling [80,81,[84][85][86].…”

Neodymium and gadolinium extraction from molten fluorides by reduction on a reactive electrode

“…Pyrochemical methods and especially electrochemistry in molten salts have already provided promising results [1][2][3][4][5][6][7]. One of the key aims of the reprocessing is lanthanide extraction from the nuclear waste.…”

Separation characteristics of a spent fuel surrogate in the molten salt electrorefining process

“…The separation factor (SF) for the estimation of the partitioning characteristics between the two elements was defined by Sakamura et al [13,14] as…”