The Chemistry of Protactinium. IX : A Study of the Solvent Extraction of Protactinium (V) from a Perchloric Acid Solution Using Di (2-ethylhexyl) phosphoric Acid as the Extractant

Studies of the chemical behavior of protactinium (V) in a perchloric acid solution were carried out by the HDEHP-benzene extraction method. When the protactinium concentration was lower than 10^M, the extraction reaction was considered to proceed as : PaO(OH)^_+3(HA)_=PaO_ p(OH)_qA_(HA)_+2H+_+(2-p-q)H_2O_ where p=1, q=0 or 1 and p=2, q=0 and Pa(OH)_3^_+3 (HA)_=PaO_p(OH)_qA_(HA)_+2H+_+(3-p-q)H_2O_ where p=0, q=0, 1, 2, or 3 ; p=1, q=0 or 1 and p=2, q=0

The Mutual Separation of ^<227>Ac, ^<227>Th, ^<223>Ra, and ^<223>Fr by the Solvent Extraction Technique Using Bis(2-ethylhexyl)phosphoric Acid as an Extractant(Chemistry)

The separation and purification of ^Ac, ^Th, ^Ra, and ^Fr were studied by the solvent extraction method using HDEHP (bis(2-ethylhexyl)phosphoric acid) as an extractant. The mutual separation of Ac, Th, and Ra was achieved, and new milking processes for ^Fr and ^Ac are presented

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

A Systematic Calculation of Nuclear Yields at the Production of Transuranium Elements by Multi-step Neutron Irradiation in a Reactor

A general procedure, which is amenable to computer programming, is developed for the evaluation of nuclear yields at the production of transuranium elements by multi-step neutron irradiation in a reactor. Chain members in nuclear transformation chains are progressively chosen, and chain member yields are systematically calculated. All reaction chains that start from nuclides produced at the preceded step are traced, and nuclear yields are obtained by the separate summation of chain member yields ; they are then used as initial nuclear yields at the next step. When these treatments are continued till the last step, final nuclear yields are obtained. The yields of fission product nuclides can be also evaluated by the developed procedure without any modification

Neutron Activation Analysis of Thorium by the Use of the Japan Materials Testing Reactor

Hydraulic power rabbit in the Japan Materials Testing Reactor (JMTR) was used for highly sensitive neutron activation analysis of thorium in silica and aluminum. The thermal neutron flux of JMTR is higher than 1x10^n/cm^2/sec. A number of radioactive isotopes were made from impurities of high purity aluminum and silica irradiated in JMTR. ^Ta, which was produced from ^Ta by (2n, γ) reaction, was observed and made the determination of thorium difficult. The objective activation products ^Pa for the determination of thorium was isolated from majority of interfering radioactivity by a method combined with anion exchange and LaF_3 coprecipitation. It was found that the detection limit of thorium was less than 2x10^g. The method is useful to the analysis for thorium in high purity aluminum and silica that might be used to make very large scale integrated circuit

Production of Curium by the Neutron Irradiation of Americium-241

^Am was irradiated by the Japan Material Testing Reactor. The group separation of transuranium elements from fission products and cladding materials were carried out, and then Np, Pu, Am and Cm were isolated by using the ion exchange method. The isotopic ratios of Cm and Am were determined by the α- and γ-ray spectrometry

227Th-EDTMP: A potential therapeutic agent for bone metastasis

金沢大学大学院医学系研究科保健学専攻The biodistribution of 227Th-EDTMP and retention of its daughter nuclide 223Ra were examined. 227Th-EDTMP was found to show high uptake and long-term retention in bone. The clearance of 227Th-EDTMP from blood and soft tissues was rapid and the femur-to-tissue uptake ratios reached more than 100 within 30 min for all tissues except the kidney. Seven and 14 days after injection of 227Th-EDTMP, the retention index of 223Ra in bone showed high values, and the differences between these time points were not significant. Therefore, 227Th-EDTMP is a potential radiotherapeutic agent for bone metastasis

Irradiation of Natural Uranium by the Neutrons of the Japan Material Testing Reactor

A 2.76 g of natural uranium dioxide was irradiated by the neturons of JMTR for about 60 days from the 7th cycle to the 9th cycle. U and Pu were isolated and the isotopic ratios were measured. The nature of the neturon capture reactions was discussed

Observation of α-decay of ^<229m>Th produced from ^<229>Ac(II. Radiochemistry)

We produced ^Th in the nuclear reaction ^Th(γ, p2n)^ Ac, followed by disintegration to ^Th. The α-decay signals from ^Th were searched for and the alpha-particle events of the energy region between 4.93MeV and 5.05MeV were observed in the separated thorium fraction from an actinium source highly purified from the ^Th+γ reaction products. The energy values of the α-particles coincide with those expected for ^Th