DIAMEX-SANEX process development studies

X Hérès (1) , C Hill (1) , L Berthon (1) , P Rigaux (1) , E Ameil (1)

1 DMRC - Département de recherche sur les procédés pour la mine et le recyclage du combustible

This paper describes the way adopted to develop DIAMEX-SANEX process. The organic phase contains two extractants : DMDOHEMA extracting actinides(III) from a high nitric acid medium, and the a cationic exchanger for the extraction at lower acidity. Two concepts are studied : in the first one, extractants mixture is used in the whole process, whereas the second route includes a extractant separation step. In that case, only DMDOHEMA is exposed to high-level raffinate and Mo, Zr extraction could be inhibited. In that case, di-alkyl phosphoric acids with 6 carbon atom on branched chains were the more convenient for actinides and extractant separations. They are lipophilic towards aqueous solutions with pH lower than 4, in order to maintained lanthanides in organic phase. They are moreover soluble in basic aqueous solution, so we could recover a organic phase with only DMDOHEMA and TPH. The route without extractant separation used the well known di-(2-ethyl hexyl) phosphoric acid. The main difficulty in that case, is the management of fission products as molybdenum and zirconium, in order to prevent their stripping with actinides(III) and to back extract them before organic phase recycling. The main goal of theses studies is to carry out experiments useful to elaborate a flowsheet for a genuine hot test on a long duration in 2004.

Domains: Chemical Sciences; Chemical Sciences; Chemical engineering; Chemical Sciences; Inorganic chemistry

X Hérès, C Hill, L Berthon, P Rigaux, E Ameil. DIAMEX-SANEX process development studies. Atalante 2004 - Advances for future nuclear fuel cycles, Jun 2004, Nimes, France. ⟨cea-03541438⟩