Chemical Studies on the extraction of certain elements related to the nuclear fuel cycle

Abstract

Lanthanides and yttrium represent a considerable portion of the fission products obtained from uranium-235 fission in the back end of nuclear fuel cycle. Therefore, it is rather relevant to investigate their extraction chemistry to get more information concerning their behavior towards the novel extractant Cyanex 572. Therefore, the main objective of the work presented in this thesis is directed to study the extraction and separation of Y(III) and Dy(III) from different diluted mineral acid solutions such as HCl, HNO3 and H2SO4 using Cy-572 as a novel extractant diluted in kerosene. The characterization of Cy-572 using different analysis such as potentiometric titration, FT-IR measurements, GC-Mass spectrometry and NMR measurements was studied to identify the ratio of its main components. Within this context two systems are studied based on liquid– liquid extraction and solid–liquid extraction. Recovery of the investigated elements from loaded organic solutions using different stripping agents was carried out. The thesis is classified into three chapters; namely, introduction, experimental, and results and discussion.

The first chapter, "Introduction", includes a brief outline on the nuclear fuel cycle including front end cycle and back end cycle, spent nuclear fuel and the composition of irradiated fuel. Also, the basic aspects of different separation techniques with a special consideration on extraction techniques especially extraction