K. Uozumi et al., Pyrometallurgical partitioning of uranium and transuranic elements from rare earth elements by electrorefining and reductive extraction, J NUC SCI T, 38(1), 2001, pp. 36-44
High-level liquid waste generated from PUREX reprocessing contains a small
amount of transuranic elements, such as Np, Pu, Am. and Cm, with long-lived
radioactivities. A pyrometallurgical partitioning process is being develop
ed to recover transuranic elements from such waste. Small amounts of U cont
ained in the high-level liquid waste are also recovered in the process. A k
ey issue for developing the process is effective separation of U and the tr
ansuranic elements from the rare-earth elements, because the two elemental
groups are chemically analogous. A series of process tests were carried out
in the present study to demonstrate that a combination of electrorefining
and reductive extraction is useful for separating U and transuranic element
s from the rare-earth elements. The results indicate that 99% of U and each
transuranic element is recovered by the combination process as a product,
and that the quantity of rare-earth elements contained in the product is sm
aller than the transuranic elements by weight. The overall mass balance of
U and transuranic elements in the system ranged within the experimental err
ors assigned to sampling and analysis.