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AbstractAbstract
[en] This study is concerned first with the effects of gamma rays on plutonium aqueous solutions at various valency states, in presence of sulfuric, perchloric, nitric and hydrochloric acids. The main feature is the reduction of Pu VI into Pu V, followed by dismutation from V to IV and VI. For sulfuric and perchloric acid solutions (0,2 N) the following process is given: radiolysis of water produces OH, H2O2, H and H2. H and H2O2 reduce Pu VI while Pu V is oxidised by OH radicals. However the reaction of hydrogen peroxide is slow and leads to an after effect. A parallel study of the action of H2O2 has given a confirmation. Spectrophotometric measurements were carried out on disappearance of Pu VI and formation of Pu IV and it was possible to make determination of GH2O2 = 0,8 and GH - GOH = 0,8. GH2 = 0,41 was measured by gas analysis. The calculation of G-H2O gave 4,35. The re-oxidation of Pu V is dependant on the concentration of sulfate ions. In perchloric acid solution reduction goes on to Pu Ill. Cl- and NO3- ions inhibit the reduction and even suppress it. The effect of alpha particles both from plutonium and from polonium is very similar to the effect of hydrogen peroxyde. Induction time were observed mainly in presence of HSO4-, depending on the accumulation of H2O2 and (or) of plutonium peroxide. At low acidities, Pu IV peroxide seems to lead to polymer forms. In the more simple cases (H2SO4 and HClO4 0,2N), the following yields were found: G (equivalent reduced) = 3.2, GH2O2 = 1.35, GH2 = 1.6 and GH - GOH = 0.1, assuming GHO2 = 0.2; and the usual hypothesis on radiolysis of water by alpha particles. Radiation induced oxidation of Pu III into Pu IV was also observed in H2SO4 and HNO3 aqueous solutions, and reduction of IV into III was measured with HClO4. (author)
[fr]
On a etudie l'action des rayons gamma sur les solutions aqueuses de plutonium a divers etats de valence, en milieu sulfurique, perchlorique, nitrique et chlorhydrique. Le phenomene principal est la reduction de Pu VI en Pu V suivie de la dismutation de la valence V en VI et IV. Pour les solutions d'acide sulfurique et perchlorique 0,2N on a donne le mecanisme des reactions: la radiolyse de l'eau conduit aux produits OH, H2O2, H et H2. Pu VI est reduit par H and H2O2 tandis que Pu V est reoxyde par OH. Cependant l'action de l'eau oxygenee est lente et provoque un effet prolonge. Une etude menee parallelement sur l'action de H2O2 a confirme ceci. Les mesures de disparition de Pu VI et d'apparition de Pu IV faites par spectrophotometrie ont conduit a determiner GH2O2 = 0,8 et GH - GOH = 0,8. Par microanalyse de gaz on a mesure GH2 = 0,41. Ces donnees permettent de calculer le rendement de radiolyse de l'eau G-H2O = 4,35. Les ions sulfate ont une influence complexe sur la reoxydation de Pu V comme le montrent les resultats obtenus sur des solutions plus concentrees en H2SO4. La reduction se poursuit jusqu'a la valence Ill en milieu perchlorique. Les ions Cl- et surtout NO3- inhibent la reduction et peuvent la supprimer completement. L'action des particules α du plutonium et du polonium est tres analogue a celle de l'eau oxygenee. La reduction a lieu apres des periodes d'induction plus ou moins longues selon l'anion (surtout HSO4- ). Elles sont liees a l'accumulation de H2O2 et (ou) de peroxyde de plutonium. Aux faibles acidites le peroxyde de Pu IV a tendance a conduire a des formes polymerisees. Dans les cas les plus simples (H2SO4 et HClO4 0,2N) les rendements suivants ont ete obtenus ou calcules: G (reduction en equivalents) = 3,2, GH2O2 = 1.35, GH2 = 1.6 et GH - GOH = 0.1, en supposant que GHO2 = 0,2. On a pris les hypotheses habituellement admises sur la radiolyse de l'eau par les rayons α. L'oxydation de Pu III en Pu IV par les rayonnements α ete egalement observee en presence de H2SO4 et HNO3 tandis que la reduction de Pu IV en Pu III etait mesuree en milieu perchlorique. (auteur)Original Title
Radiolyse des solutions aqueuses de plutonium
Primary Subject
Source
1960; 80 p; 48 refs.; These ES sciences physiques
Record Type
Report
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Thesis/Dissertation
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ACTINIDE COMPOUNDS, ACTINIDES, BEAMS, CHARGED PARTICLES, CHEMICAL RADIATION EFFECTS, CHEMICAL REACTIONS, CHEMISTRY, CHLORINE COMPOUNDS, DECOMPOSITION, DISPERSIONS, ELECTROMAGNETIC RADIATION, ELEMENTS, HALOGEN COMPOUNDS, HELIUM 4 BEAMS, HOMOGENEOUS MIXTURES, HYDROGEN COMPOUNDS, INORGANIC ACIDS, INORGANIC COMPOUNDS, ION BEAMS, ION SOURCES, IONIZING RADIATIONS, IONS, METALS, MIXTURES, OXYGEN COMPOUNDS, PARTICLE SOURCES, RADIATION EFFECTS, RADIATION SOURCES, RADIATIONS, RADIOCHEMISTRY, SOLUTIONS, SULFUR COMPOUNDS, TRANSURANIUM COMPOUNDS, TRANSURANIUM ELEMENTS
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