Distribution Coefficients of Americium, Neptunium, and Protactinium for Selected Rocks

Distribution coefficients (Kᴅ) were measured by a batch technique for sorption-desorption of americium(III), neptunium(V), and protactinium(V) between granite, tuff, or quartz mined in Japan, and water. Measurements were performed at room temperature. The effects of the surface area, pH, and the separation method of solid and liquid phases were studied. The Kᴅ values of americium ranged from 50 to 370000 (mL/g), depending much on the separation methods adopted due to the presence of colloidal particles of americium in solutions. The Kᴅ values of neptunium were small (0.67-13 mL/g), and were little affected by the experimental conditions employed. Protactinium had intermediate values of Kᴅ. The physical adsorption was suggested in the sorption experiments for americium on latex particles

Reductive Extraction of Actinides and Lanthanides from Molten Chloride Salt into Liquid Zinc

As one of the basic investigations on the group partitioning of actinides and lanthanides by pyrochemical reductive extraction system, their distribution behavior in a binary phase system of molten chloride and liquid zinc was studied, Generally speaking, actinides were a litte more easily reduced and extracted from the salt phase into the metal phase than lanthanides. However, the separation factors which were the differences in the distribution coefficient between actinides and lanthanides were not so large even at lower temperatures, and the group partitioning of these elements seemed less attractive in this system. The present results were much the same as those in the LiF-BeF_2/Zn system and the effect of the selection of the salt phase on the separation factors were hardly observed. For some details, the thermodynamic quantities of actinides and lanthanides in the system were calculated from the equilibrium distributions and discussed

スズ アンチモン オヨビ テルル カク ブンレツ セイセイブツ ノ カガク キョドウ

京都大学0048新制・課程博士工学博士甲第2543号工博第696号新制||工||500(附属図書館)UT51-56-G56京都大学大学院工学研究科工業化学専攻(主査)教授 西 朋太, 教授 岩田 志郎, 教授 兵藤 知典学位規則第5条第1項該当Kyoto UniversityDFA

Hydrogen traps in ion-irradiated F82H steel observed by NRA

Characteristics of irradiation-induced trapping of hydrogen were investigated for quantitative evaluation of tritium retention in F82H steel. Before and after irradiation of 0.8-MeV 4He or 0.3-MeV H ions, deuterium depth profiles near the surface of a disk sample were observed by nuclear reaction analysis under continuous exposure of deuterium plasma. One type of trap, with a trapping energy of 0.66 eV, was observed after each irradiation. The ratio of trap production rate to atomic displacement was 0.0046 and 0.0014 for He and H irradiation, respectively. Annihilation occurred around 600 K for H irradiation but was not observed even at 691 K for He irradiation. Traps are likely to be interstitial-like sites associated with dislocation loops. This study also indicates that helium plays a role in inhibiting trap annihilation. In addition, the deuterium diffusion coefficient in non-irradiated F82H was determined by a time-lag permeation experiment