Investigation on partitioning and utilization of valuable elements and radio isotopes from spent nuclear fuel

Saga, Kaname

JAEA-Review 2024-038, 9 Pages, 2024/09

JAEA-Review-2024-038.pdf:0.88MB

The purpose of this report is understanding the elements and radio isotopes with highly useful based on the current trends in the industrial field. The survey was conducted from the viewpoint of the abundance of elements and radio isotopes contained and the demand in the industrial field, and the following survey results were obtained. The economic scale of radio isotopes in the industrial field (including radiation use) has been increasing in recent years in the manufacturing, medical, and agricultural sectors. On the other hand, the domestic production of the utilized radio isotope is still small, and some radio isotopes are entirely imported. Radio isotopes such as Sr-90, Mo-100, Cs-137, and Am-241 from spent fuel are suitable for industrial use because of their abundance in spent fuel and half-lives. As for the utilization of elements, the industrial use of platinum group elements and rare earth elements were explored because these elements are high industrial value and low domestic self-sufficiency. The platinum group elements were evaluated to have the potential to be supplied in a certain amount as a new domestic production source based on their abundance in spent fuel. On the other hand, for rare earth elements, which have also low self-sufficiency rate, the ratio of the amount that could be supplied from spent fuel compared to the current annual supply was evaluated to be less than 1%, and therefore, no effect could be expected. The domestic recycling rate of rare earth elements is low, and the provision of numerical simulation technology, which improves the recycling rate, could highly contribute to the industries. This technology makes it possible to calculate the optimal operating conditions for the separation process, such as the number of processing stages and processing speed, in accordance with the elements to be separated and used.

Direct temperature-swing extraction of rare-earth elements from acidic solution using the hydrophobic interactions of poly(-isopropylacrylamide) with diglycolamide-typed ligands

Saga, Kaname*; Suzuki, Hideya; Matsumura, Tatsuro; Tsukahara, Takehiko*

Analytical Sciences, 35(4), p.461 - 464, 2019/04

https://doi.org/10.2116/analsci.18N023

The phase transition-based gelification phenomenon of poly--isopropylacrylamide (PNIPAAm) in aqueous solutions has a great potential in developing new waste-free extraction processes of metal ions. By using hydrophobic diglycolamide-typed ligands in gelification extraction, a one-step complete extraction of all the RE ions from a nitric acid solution was successfully realized.