The Eurex Process: Processing of Irradiated U-Al Alloys by Amine Solvent Extraction

Degradation des amines tertiaires aliphatiques à longue l′ahaîne par l′acide nitrique et sous l'influence des radiations

“…Son application aux divers problemes du traitement par voie aqueuse des combustibles irradi^s a eu dans les dernieres annöes un d^veloppement tr^s remarquable, ä cause du grand pouvoir extractif et de la sölectivite demontr^s par ces substances [1]. L'hypothese seien laquelle les amines, contrairement aux autres substances employ^es comme agents d'extraction (par exemple le TBP) prfeentent une bonne resistance aux radiations [2][3][4][5][6], a sans doute contribuö ä, la difFusion de leur emploi dans ce domaine. Cependant la degradation des amines par les radiations et en pr^sence de l'acide nitrique n'a pas objet d'6tudes dötaill^es et approfondies, l'attention s'^tant polaris6e surtout sur les aspects pratiques de la degradation, comme la formation d'ömulsions, la rötention dans la phase organique de ruranium et du plutonium, et la decontamination des produits de fission.…”

Aqueous Reposessing of Reactor Fuel

“…Unlike the TBP extraction, the complex acid HU02-(N03)3 is inextractable (18) by amines above 6 M HN03.…”

“…The extraction mechanism of the actinides with amines from nitric acid solutions is explained based on an anion-exchange process, similar to an anion-exchange resin. The tetravalent actinides are extracted as (BH)2M(N03)6 whereas the hexavalent actinides are extracted as BH • M02(N03)3 or (BH)2M02(N03)4 from nitric acid solutions (18,63,64,(112)(113)(114)126,171,195,203,205,208).…”

A Review of the Solvent Extraction Process Chemistry of Fission Products

“…Tertiary amines are very stable to radio lytic attack [27] but, nevertheless, some degradation products are formed which reduce the Zr DF. The degradation products can successfully be removed from the solvent by washing with HNOj and NaOH [28], Proposals for the use of tertiary amines in reprocessing are based principally on their power to extract Pu (IV) highly selectively and on their retention of performance under irradiation [29]. These properties would be particularly useful in fast breeder fuel reprocessing where it is important to recover the Pu quickly; the U being depleted …”