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

セラミック ザイリョウ ニ オケル ショウシャ ケッカン ノ セイセイ ト ハンノウ ニ カンスル ケンキュウ

京都大学0048新制・論文博士博士(工学)乙第12335号論工博第4013号新制||工||1466(附属図書館)27190UT51-2009-D550(主査)教授 森山 裕丈, 教授 伊藤 秋男, 教授 高木 郁二学位規則第4条第2項該当Doctor of EngineeringKyoto 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

Equilibrium Distributions of Actinides and Lanthanides in Molten Salt and Liquid Metal Binary Phase Systems

In support of the development of a pyrochemical group partitioning process of actinides and lanthanides, the equilibrium distributions of these elements were measured in some binary phase systems of molten salt and liquid metal. LiF-BeF_2 mixture was selected as the salt phase, and Bi, Sn, Cd and Zn were examined as the metal phase. In general, actinides were more easily reduced and extracted from the salt phase into the metal phase than lanthanides. The group partitioning is thus feasible. In different partitioning systems, systematic difference in the separation factor between actinides and lanthanides was observed. The difference is attributable to the difference in alloying energies in the metal phase