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- Author or Editor: K. Park x
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Abstract
It is important to increase a throughput of the salt removal process from uranium deposits which is generated on the solid cathode of electro-refiner in pyroprocess. In this study, it was proposed to increase the throughput of the salt removal process by the separation of the liquid salt prior to the distillation of the LiCl–KCl eutectic salt from the uranium deposits. The feasibility of liquid salt separation was examined by salt separation experiments on a stainless steel sieve. It was found that the amount of salt to be distilled could be reduced by the liquid salt separation prior to the salt distillation. The residual salt remained in the deposits after the liquid salt separation was successfully removed further by the vacuum distillation. It was concluded that the combination of a liquid salt separation and a vacuum distillation is an effective route for the achievement of a high throughput performance in the salt separation process.
Abstract
This communication presents the comparative experimental study of solar cookers based on the exergy analysis. In this study two different types of solar cookers viz. paraboloid type and box type have been evaluated using exergy analysis. The experiments have been carried out with cookers filled with different volume of water viz. one and two liters along with the suitable quantity of rice. Data of temperatures and solar radiation have been measured for different food stuff on clear sky day of the month. It is found that the exergy efficiency increases as the volume of water increases, however, the exergy efficiency of paraboloid solar cooker is found to be higher than that of the box-type solar cooker for all the cases mentioned above. However, it is also found that the exergy efficiency vary with the cooking stuff and water which is due to the fact that the requirement of heating vary with the food stuff.
Abstract
A radiochemical separation method using Dowex 1×8 (200–400 mesh) has been applied to two tantalum metals of 99.9% purity. While tantalum was still retained on the resin, the elements Na, K, Cr, Mn, Fe, Co and Zn were separated with 2M HF and subsequently the elements Sc, As, Zr, Mo, Eu, W and Hf with a mixture of 0.5M HF and 3M HCl. The separation yields for all impurities was 98–100%. Elemental contents were calculated by a single comparator method using two monitors.
Abstract
This paper describes ongoing research into the multi-physics model development of an electrorefining process for the treatment of spent nuclear fuel. A forced convection of molten eutectic (LiCl–KCl) electrolyte in an electrorefining cell is considered to establish an appropriate electro-fluid model within the 3-dimensional framework of a conventional computational fluid dynamic model. This computational platform includes the electrochemical reaction rate of charge transfer kinetics which is described by a Butler–Volmer equation, while mass transport is considered using an ionic transport equation. The coupling of the local overpotential distribution and uranium concentration gradient makes it possible to predict the local current density distribution at the electrode surfaces.
Abstract
Interferences by uranium fission for95Zr,99Mo,103Ru,140La,141Ce and147Nd have been studied using a single comparator method with two monitors. The effect of the neutron energy spectrum on the interference factor was examined by using the effective activation cross section. All the activities of140La produced during neutron irradiation of uranium were included in the calculation of the factor for lanthanum. The calculated and experimental interference factors are in good agreement within 10% deviation. The results have been applied for the analysis of several rock samples containing uranium in a wide concentration range.
Abstract
A radiochemical separation method using an anion exchange resin has been applied to 3N grade Nb for determining nine impurity elements. Five elements (Cr, Fe, Co, Zn and Se) were separated in 2M HF, three elements (Mo, W and Hf) in 32M HF, Nb in 0.5M HF/3M HCl, and Ta in 1M NH4F/4M NH4CCl. The contents of the elements were calculated by a single comparator method using two monitors of Au and Co. The main impurity was revealed to be Ta with a content of over 160 ppm.
Abstract
A radiochemical neutron activation analysis has been applied to 2N–4N grade titanium metal and its oxide. Twenty two impurities were separated in a group from scandium by a radiochemical separation method using cation exchange resin with HBr and HCl. The contents of the elements were calculated by a single comparator method using two monitors. The analytical results agree well within 10% deviation with those obtained by instrumental method. Eighteen elements, Na, Fe, Co, As, Se, Sr, Mo, Sb, La, Eu, Tb, Yb, Lu, Hf, Ta, W, Th and U, are determined in titanium oxides and 17 elements, Na, Cr, Fe, Co, Se, As, Zr, Mo, Sb, Cs, Ce, Tb, Yb, Hf, Ta, W and Th, in titanium metals.
Abstract
Neutron activation analysis has been applied to determine 12 elements, viz. Na, Mn, As, Fe, Co, Zn, Se, Sc, Cr, Sb, Hf and Ta in high-purity Ga2O3. The first 7 elements could be determined by anion exchange separation and isopropyl ether extraction, and the last 8 elements by instrumental method. It is recommended that the first 3 elements are determine by one of the radiochemical modes and the others by the instrumental method.
Abstract
Instrumental neutron activation analysis has been applied to semiconductor grade silicon to study the concentration levels of impurity elements, the contamination during the single crystal growing process, and the vertical and radial distributions of impurities, along with the decontamination effect in the analysis. Twenty elements of Au, Br, As, W, Cr, Co, Na, Eu, La, Se, Zn, U, Th, Hf, Fe, Sb, Ag, Ce, Tb and Ta have been analyzed in p- and n-type wafers, single crystals and a polycrystal by a single comparator method using two comparators of gold and cobalt. Considerable surface contamination has been found and could be removed by etching the surface with nitric and hydrofluoric acid before and after irradiation. The impurity concentration has been found to be generally increased in the process of single crystal growth. The vertical and radial distributions of impurities have revealed that some impurity elements were more concentrated in the top region of a single crystal rod than in the middle region, and that Br, Cr, La, Eu and Sb were enriched in the central region and As, U and Fe in the outer region.
Abstract
A study on the separation of lithium isotope was carried out with a 1,16-dioxa-4,7,10,13- tetraazacyclooctadecane-4,7,10,13-tetramerrifield peptide resin [N4O2·4M]. The resin having N4O2 as an anchor group has a capacity of 3.8 meq/g. Upon column chromatography [0.15 cm (I.D)×29 cm (height)] using 0.01 M NH4Cl as an eluent, the single separation factor, α=1.038 was obtained by the Glueckauf theory from the elution curve and isotope ratios.
