• Analytical Science and Technology
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• v.23 no.1
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• pp.45-53
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• 2010

For the determination of chlorine in uranium compound, analytical methods by using a steam distillation and a pyrohydrolysis have been developed. The steam distillation apparatus was composed of steam generator, distilling flask and condenser etc. The samples were prepared with an aliquot of LiCl standard solution and a simulated spent nuclear fuel. A sample aliquot was mixed with a solution containing 0.2 M ferrous ammonium sulfate-0.5 M sulfamic acid 3 mL, phosphoric acid 6 mL and sulfuric acid 15 mL. The chloride was then distilled by steam at the temperature of $140^{\circ}C$ until a volume of $90{\pm}5\;mL$ is collected. The pyrohydrolysis equipment was composed of air introduction system, water supply, quartz reaction tube, combustion tube furnace, combustion boat and absorption vessel. The chloride was separated from powdered sample which is added with $U_3O_8$ accelerator, by pyrohydrolysis at the temperature of $950^{\circ}C$ for 1 hour in a quartz tube with a stream of air of 1 mL/min supplied from the water reservoir at $80^{\circ}C$. The chlorides collected in each absorption solution by two methods was diluted to 100 mL and measured with ion chromatography to determine the recovery yield. For the ion chromatographic determination of chlorine in molten salt retained in a metal ingot, the chlorine was separated by means of pyrohydrolysis after air and dry oxidation, and grinding for the sample.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.4
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• pp.321-332
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• 2017

In order to build a general model of a high-throughput uranium electrorefining process according to the electrode configuration, numerical analysis was conducted using the COMSOL Multiphysics V5.3 electrodeposition module with Ordinary Differential Equation (ODE) interfaces. The generated model was validated by comparing a current density-potential curve according to the distance between the anode and cathode and the electrode array, using a lab-scale (1kg U/day) multi-electrode electrorefiner made by the Korea Atomic Energy Research Institute (KAERI). The operating temperature was $500^{\circ}C$ and LiCl-KCl eutectic with 3.5wt% $UCl_3$ was used for molten salt. The efficiency of the uranium electrorefining apparatus was improved by lowering the cell potential as the distance between the electrodes decreased and the anode/cathode area ratio increased. This approach will be useful for constructing database for safety design of high throughput spent nuclear fuel electrorefiners.

• Resources Recycling
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• v.24 no.6
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• pp.9-16
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• 2015

In a recycling scheme of spent lithium ion batteries, a co-precipitation process for the re-synthesis of precursor is essential after the leaching of lithium ion battery scraps. In this study, the effect of ammonia as impurity during the co-precipitation process was investigated in order to re-synthesize a precursor of Ni-rich cathode active material $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ (NCM 622). As ammonia concentration increases from 1 M (the optimum condition for synthesis of the precursors based on 2 M of metal salt solution) to 4 M, the composition of obtained precursors deviates from the designed composition, most notably for Ni. The Ni co-precipitation efficiency gradually decreases from 100% to 87% when the concentration of ammonia solution increases from 1 M to 4 M. Meanwhile, the morphological properties of the obtained precursors such as sphericity, homogeneity and size distribution of particles were also investigated.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4660-4670
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• 2022

Hydroxyurea (HU) is a novel salt-free reductant used potentially for the separation of U/Pu in the advanced PUREX process. In this work, the radiation stability of HU were systematically investigated in solution by examining the effects of the type of rays (α, β, and γ irradiations), the absorbed dose (10-50 kGy), and the HNO₃ concentration (0-3 mol L^-1). The influence degree on HU radiolysis rates followed the order of the absorbed dose > the ray type > the HNO₃ concentration, but the latter two had moderate effects on HU radiolysis products where NH₄⁺ and NO₂^- were found to be the most abundant ones, suggesting that the differences of α, β, and γ rays should be considered in the study of irradiation effects. The radiolysis mechanism was explored using density functional theory (DFT) calculations, and it proposed the dominant radiolysis paths of HU, indicating that the radiolysis of HU was mainly a free radical reaction among ·H, e_aq^-, H₂O, intermediates, and the radiolytic free radical fragments of HU. The results reported here provide valuable insights into the mechanistic understanding of HU radiolysis under α, β, and γ irradiations and reliable data support for the application of HU in the reprocessing of spent fuel.

• Korean Journal of Food Science and Technology
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• v.13 no.3
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• pp.171-175
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• 1981

Hand deboned and mechanically deboned chicken meat were produced from domestic broilers and spent layers. Meat yield, chemical composition, functional characteristics, storage stability and microbiogical properties were investigated. The results obtained were as follows: 1. 35% of carcass freight was recovered primarily as hand deboned chicken meat (HDM) and 45% secondarily as mechanically deboned chicken meat(MDM), total meat yield reaching 80% of carcass weight. 2. Moisture, protein, fat. ash and calcium content of MDM were 65, 12, 20, 1.7 and $0.2{\sim}0.4%$, respectively MDM was higher than HDM in fat, ash and calcium, but significantly lower in moisture and protein Total pigment content of MDM was 2.5 times higher than that of HDM, such high content being attributed to the increased inclusion of hemoglobin during the mechanical masceration of carcass in the deboning process. 3. The emulsifying capacity (ES) of MDM per g meat was only 70% that of HDM, but when ES was expressed on unit g of protein basis MDM showed even higher ES than HDM primarily due to the higher proportion of salt soluble protein fraction of MDM. 4. Since the TBA value of MDM increased rapidly after 4 weeks of frozen storage at $-20^{\circ}C$, the maximum possible storage period of MDM is estimated to be about 4 weeks. 5. Total microbial counts of MDM was approximately $1.8{\times}10\;cells/g$ showing no great difference from HDM or red meat.

• Korean Journal of Poultry Science
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• v.7 no.2
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• pp.37-46
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• 1980

Hand deboned and mechanically deboned chicken meat were produced from domestic broilers and spent layers. Meat yield, chemical composition, functional characteristics, stability during storage, and microbiological properties were investigated Chicken patties and frankfurters were also manufactured by varying the relative proportion of MDCM to HDCM as raw materials, ana their palatability, shelf-life and textural properties were evaluated. The obtained results were as follows: 1) 35% of carcass wt was recovered as HDCM and 45% as MDCM, total meat yield reaching 80% of carcass wt. 2) Moisture, protein, fat, ash and Ca content of MDCM were 65, 12, 20, 1.7 and 0.2-0.4%,respectively. MDCM was higher in fat, ash and Ca, but significantly lower in moisture and protein. Total pigment content of MDCM was 2.5 times higher than that of HDCD such high content being attributed to the increased inclusion of hemoglobin. 3) The emulsifying capacity (ES) of MOCM per g meat was only 70% that of HDCM. but when ES was expressed on unit g of protein basis MDCM showed even higher ES than HDCM primarily due to tile higher proportion of salt soluble protein fraction. 4) Since the TBA values of MDCM increased rapidly after 4 weeks of frozen storage at -20$^{\circ}C$, the maximum possible storage period of MDCM is estimated to be about 4 weeks. 5) Total microbial counts of MDCM was approximately 1.8${\times}$10$\^$6/g/, showing no great difference from HDCM or red meat. 6) Chicken patty containing MDCM showed gradual increase in TBA value during frozen storage, but its storage up to 8 weeks presented no problems in flavor stability. 7) Color score an4 total palatability of chicken Patty were best for the product containing 30% MDCM. It was also concluded that MDCM can be included in the patties up to 50% of total meat with good results, but more than 70% was not recommended 8) The formulation of MDCM up to 50% in frankfurter gave quite satisfactory acceptability and textural properties comparable to frankfurter made of 100% MDCM, but the inclusion of more than 70% MDCM was not recommended 9) The TBA value of frankfurter containing MDCM did not increase to any great extent until 4 weeks of storage at 4$^{\circ}C$, indicating no unique problems in flavor instability compared to regular frankfurter. 10) It was concluded that processed meat products such as patties and frankfurters containing MDCM up to 30-50% of total meat ingredients gave satisfactory results in color, texture and palatability, comparable to regular products.