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Min Ku Jeon - One of the best experts on this subject based on the ideXlab platform.
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a tga study on the Chlorination Reaction kinetics of zircaloy 4 cladding hulls
Journal of Nuclear Materials, 2015Co-Authors: Min Ku Jeon, Yong Taek Choi, Kweon Ho Kang, Geun Il ParkAbstract:Abstract The Chlorination Reaction kinetics of Zircaloy-4 cladding hulls were investigated using a home-made thermogravimetric analysis for a hull Chlorination (TGA-HC) system. The reproducibility of the TGA-HC system was verified by repeated measurements at an identical condition, which showed only 6.6% of maximum difference. The effect of total flow rate ( Q ) was investigated for Q of 120 and 240 mL/min, and it was revealed that the Reaction rate is not influenced in this condition. Using the Sharp–Hancock plot, the volumetric contraction model was identified as the most suitable model for the Zircaloy-4 Chlorination Reaction. The influence of chlorine partial pressure was studied at 9.21, 16.9, and 23.4 kPa of Cl 2 partial pressure conditions, and it was identified that the Reaction rate is proportional to the chlorine partial pressure on the order of (0.669). The effect of Reaction temperature was investigated for 300–450 °C, and it was revealed that the Chlorination Reaction exhibits an activation energy of 26.2 kJ/mol. Using the experimental and fitting results, the Reaction rate equation for the Zircaloy-4 Chlorination Reaction was achieved, but the equation was valid only until the conversion fraction ( α ) reaches up to (0.60). When α is higher than 0.60, the volumetric contraction model was not applicable. A second-order Reaction rate equation was suggested for the 0.6 α region, although it needs further investigation.
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Chlorination Reaction kinetics of CsI under cladding hull waste treatment condition: a TGA study
Journal of Radioanalytical and Nuclear Chemistry, 2015Co-Authors: Min Ku Jeon, Yong Taek Choi, Chang Hwa Lee, Deok Yoon Kang, Kweon Ho Kang, Hwan Seo Park, Do-hee AhnAbstract:The Reaction between cesium iodide (CsI) and chlorine gas was quantitatively investigated using a thermo-gravimetric analysis system. A comparison between calculated and experimental results on the chlorine molar flow rate revealed that the Reaction lies within the gas phase diffusion limited region under the condition of this work. Using the experimental data, the second-order nucleation and growth model was identified as the best geometry function to describe the morphological changes of CsI during the Chlorination Reaction. Combining the gas phase diffusion equation and geometry function, a Reaction rate equation was proposed for the Reaction between CsI and Cl2.
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Chlorination Reaction behavior of zircaloy 4 hulls a preliminary study on the effect of the oxidation process on the Reaction rate
Journal of the Nuclear Fuel Cycle and Waste Technology, 2013Co-Authors: Min Ku Jeon, Yong Taek Choi, Chang Hwa Lee, Kweon Ho Kang, Chul Min Heo, You Lee Lee, Geun Il ParkAbstract:Reaction period of 0 – 2 h. The amount of Reaction residue increased from 0.95 to 1.65wt% of initial weights in the fresh and Zry-500-10 (Zry-4 hulls oxidized at 500 o C for 10 h under an air atmosphere) hulls, respectively. The purity of the recovered Zr was identical at 99.61wt% for the fresh Zry-4 and Zry-500-10 hulls. Quantitative analysis of the Chlorination Reaction rate was performed by varying the Reaction time from 0.5 to 1.0, 2.0, and 4.0 h. The fitting results showed that the relationship between weight loss and Reaction time can be interpreted by a linear line with a slope of 23.35wt%/h for the fresh Zry-4 case, while two linear lines were necessary to fit the results of Zry-500-10. In addition, the slope values were 17.12 and 27.16wt%/h for (0 – 20) and (20 – 100)wt% loss regions, respectively.
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simulation of radioactivation and Chlorination Reaction behavior for zircaloy 4 and zirlo cladding hull wastes
Journal of Radioanalytical and Nuclear Chemistry, 2012Co-Authors: Min Ku Jeon, Chang Hwa Lee, Kweon Ho Kang, Chang Je Park, Geun Il ParkAbstract:Radioactivation of Zircaloy-4 (Zry-4) and Zirlo cladding hulls after 55 GWD/tU burn-up and 10 years of cooling was simulated using the ORIGEN-S code. The simulation results revealed that 125Sb and 60Co are major contributors of both radioactivity and decay heat in the case of the Zry-4 hulls. For the Zirlo hulls, 93mNb and 125Sb consisted 82.2% of radioactivity while 125Sb and 60Co emitted 77.9% of decay heat. Although the radioactivity between the Zry-4 (1.17 Ci for 1 kg of fresh Zry-4) and Zirlo (1.38 Ci for 1 kg of fresh Zirlo) hulls was not significantly different, decay heat of the activated Zry-4 hulls (8.58 mW) was much larger than 1.62 mW of the activated Zirlo hulls. This gap might have come from the different major constituents of Zry-4 (Zr, Sn, Fe, and Cr) and Zirlo (Zr, Sn, Nb, and Fe) resulting in different radioactive nuclides after radioactivation. Chlorination Reaction behavior of the activated Zry-4 and Zirlo hulls was performed using the HSC chemistry code. Constituents of recovered ZrCl4 were investigated via changes of Gibbs free energy and boiling points of resulting chlorides. The calculation results suggested that radioactivity and decay heat might decrease by 49.0 and 81.8%, respectively, in the ZrCl4 recovered from the activated Zry-4 hulls. In the case of Zirlo, it was expected that radioactivity and decay heat might decrease by 11.6 and 13.0%, respectively, after the Chlorination Reaction. Effect of cooling time on radioactivity and decay heat was also investigated.
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effect of oxidation conditions on Chlorination Reaction of zircaloy 4 hulls
Journal of Nuclear Materials, 2012Co-Authors: Min Ku Jeon, Chang Hwa Lee, Kweon Ho Kang, Jae Hwan Yang, Chul Min Heo, Geun Il ParkAbstract:Abstract The effect of oxidation conditions on the Chlorination Reaction behavior was investigated by using Zircaloy-4 (Zry-4) hulls oxidized at various conditions. When the hulls were oxidized at 500, 600, and 700 °C for 5 h, decrease of reactant mass after the Chlorination Reaction at 380 °C for 3 h was 41.6, 26.0, and 0.0 wt.%, respectively, while that of fresh Zry-4 hulls was 54.1 wt.%. Surface analysis results revealed that the oxidation state of Zr is significantly dependent on the oxidation temperature. The effect of oxidation time was also investigated for the Zry-4 hulls oxidized at 500 and 700 °C up to 24 h. Based on the experimental results, it was concluded that the Chlorination method is applicable to the Zry-4 hulls oxidized at 500 °C without removal of the surface oxide layers, while a pretreatment is required to recover Zr from the hulls oxidized at 700 °C.
Geun Il Park - One of the best experts on this subject based on the ideXlab platform.
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a tga study on the Chlorination Reaction kinetics of zircaloy 4 cladding hulls
Journal of Nuclear Materials, 2015Co-Authors: Min Ku Jeon, Yong Taek Choi, Kweon Ho Kang, Geun Il ParkAbstract:Abstract The Chlorination Reaction kinetics of Zircaloy-4 cladding hulls were investigated using a home-made thermogravimetric analysis for a hull Chlorination (TGA-HC) system. The reproducibility of the TGA-HC system was verified by repeated measurements at an identical condition, which showed only 6.6% of maximum difference. The effect of total flow rate ( Q ) was investigated for Q of 120 and 240 mL/min, and it was revealed that the Reaction rate is not influenced in this condition. Using the Sharp–Hancock plot, the volumetric contraction model was identified as the most suitable model for the Zircaloy-4 Chlorination Reaction. The influence of chlorine partial pressure was studied at 9.21, 16.9, and 23.4 kPa of Cl 2 partial pressure conditions, and it was identified that the Reaction rate is proportional to the chlorine partial pressure on the order of (0.669). The effect of Reaction temperature was investigated for 300–450 °C, and it was revealed that the Chlorination Reaction exhibits an activation energy of 26.2 kJ/mol. Using the experimental and fitting results, the Reaction rate equation for the Zircaloy-4 Chlorination Reaction was achieved, but the equation was valid only until the conversion fraction ( α ) reaches up to (0.60). When α is higher than 0.60, the volumetric contraction model was not applicable. A second-order Reaction rate equation was suggested for the 0.6 α region, although it needs further investigation.
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Chlorination Reaction behavior of zircaloy 4 hulls a preliminary study on the effect of the oxidation process on the Reaction rate
Journal of the Nuclear Fuel Cycle and Waste Technology, 2013Co-Authors: Min Ku Jeon, Yong Taek Choi, Chang Hwa Lee, Kweon Ho Kang, Chul Min Heo, You Lee Lee, Geun Il ParkAbstract:Reaction period of 0 – 2 h. The amount of Reaction residue increased from 0.95 to 1.65wt% of initial weights in the fresh and Zry-500-10 (Zry-4 hulls oxidized at 500 o C for 10 h under an air atmosphere) hulls, respectively. The purity of the recovered Zr was identical at 99.61wt% for the fresh Zry-4 and Zry-500-10 hulls. Quantitative analysis of the Chlorination Reaction rate was performed by varying the Reaction time from 0.5 to 1.0, 2.0, and 4.0 h. The fitting results showed that the relationship between weight loss and Reaction time can be interpreted by a linear line with a slope of 23.35wt%/h for the fresh Zry-4 case, while two linear lines were necessary to fit the results of Zry-500-10. In addition, the slope values were 17.12 and 27.16wt%/h for (0 – 20) and (20 – 100)wt% loss regions, respectively.
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simulation of radioactivation and Chlorination Reaction behavior for zircaloy 4 and zirlo cladding hull wastes
Journal of Radioanalytical and Nuclear Chemistry, 2012Co-Authors: Min Ku Jeon, Chang Hwa Lee, Kweon Ho Kang, Chang Je Park, Geun Il ParkAbstract:Radioactivation of Zircaloy-4 (Zry-4) and Zirlo cladding hulls after 55 GWD/tU burn-up and 10 years of cooling was simulated using the ORIGEN-S code. The simulation results revealed that 125Sb and 60Co are major contributors of both radioactivity and decay heat in the case of the Zry-4 hulls. For the Zirlo hulls, 93mNb and 125Sb consisted 82.2% of radioactivity while 125Sb and 60Co emitted 77.9% of decay heat. Although the radioactivity between the Zry-4 (1.17 Ci for 1 kg of fresh Zry-4) and Zirlo (1.38 Ci for 1 kg of fresh Zirlo) hulls was not significantly different, decay heat of the activated Zry-4 hulls (8.58 mW) was much larger than 1.62 mW of the activated Zirlo hulls. This gap might have come from the different major constituents of Zry-4 (Zr, Sn, Fe, and Cr) and Zirlo (Zr, Sn, Nb, and Fe) resulting in different radioactive nuclides after radioactivation. Chlorination Reaction behavior of the activated Zry-4 and Zirlo hulls was performed using the HSC chemistry code. Constituents of recovered ZrCl4 were investigated via changes of Gibbs free energy and boiling points of resulting chlorides. The calculation results suggested that radioactivity and decay heat might decrease by 49.0 and 81.8%, respectively, in the ZrCl4 recovered from the activated Zry-4 hulls. In the case of Zirlo, it was expected that radioactivity and decay heat might decrease by 11.6 and 13.0%, respectively, after the Chlorination Reaction. Effect of cooling time on radioactivity and decay heat was also investigated.
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effect of oxidation conditions on Chlorination Reaction of zircaloy 4 hulls
Journal of Nuclear Materials, 2012Co-Authors: Min Ku Jeon, Chang Hwa Lee, Kweon Ho Kang, Jae Hwan Yang, Chul Min Heo, Geun Il ParkAbstract:Abstract The effect of oxidation conditions on the Chlorination Reaction behavior was investigated by using Zircaloy-4 (Zry-4) hulls oxidized at various conditions. When the hulls were oxidized at 500, 600, and 700 °C for 5 h, decrease of reactant mass after the Chlorination Reaction at 380 °C for 3 h was 41.6, 26.0, and 0.0 wt.%, respectively, while that of fresh Zry-4 hulls was 54.1 wt.%. Surface analysis results revealed that the oxidation state of Zr is significantly dependent on the oxidation temperature. The effect of oxidation time was also investigated for the Zry-4 hulls oxidized at 500 and 700 °C up to 24 h. Based on the experimental results, it was concluded that the Chlorination method is applicable to the Zry-4 hulls oxidized at 500 °C without removal of the surface oxide layers, while a pretreatment is required to recover Zr from the hulls oxidized at 700 °C.
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Chlorination Reaction behavior of zircaloy 4 hulls experimental and theoretical approaches
Journal of Radioanalytical and Nuclear Chemistry, 2012Co-Authors: Min Ku Jeon, Kweon Ho Kang, Geun Il Park, Young Soon LeeAbstract:Chlorination Reaction behavior of Zircaloy-4 (Zry-4) cladding hulls was demonstrated by using a quartz reactor system. By reacting at 380 °C for 3 h, mass of the Zry-4 hulls decreased by 65.8 wt% with Cl2 utilization of 87.1 mol%. Composition of collected product was analyzed and it was revealed that concentration of Zr was higher than 99.97 wt%. The purity of Zr in the experimental result was higher than expectation when considering Sn (1.31 wt%) and Fe (0.25 wt%) contents which can produce gaseous SnCl4 and FeCl3 at the experimental condition. Theoretical calculations were performed to clarify the high purity of Zr by using the HSC code. The simulation results revealed that formation of ZrCl4 is more preferred than SnCl4, FeCl3, and CrCl3. The preference of chloride formation was confirmed by the theoretical calculation, and it was suggested that the major constituents of Zry-4 might react with Cl2 to produce chlorides in an order of ZrCl4 > CrCl3 > SnCl4 > FeCl3. It was also suggested that continuous removal of ZrCl4 and sufficient supply of Zr source during the Chlorination Reaction might have contributed to the high purity of Zr.
I. Gaballah - One of the best experts on this subject based on the ideXlab platform.
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An overview study of Chlorination Reactions applied to the primary extraction and recycling of metals and to the synthesis of new reagents
Thermochimica Acta, 2009Co-Authors: Ndue Kanari, Eric Allain, Robert Joussemet, J. Mochón, I. Ruiz-bustinza, I. GaballahAbstract:Energy intensive classical metallurgical processes, the depletion of high-grade ores and primary sources push the scientific and technical communities to treat lean and complex ores as well as secondary metal resources for the recovery of valuable metals. Chlorination technique could be a suitable technology for this purpose. This paper Summarizes laboratory experimentation of Chlorination processes developed for the extraction of tantalum and niobium from their bearing materials, the upgrading of chromite, the treatment of sulfide concentrates, and the decontamination of jarosite, as well as for the synthesis of potassium ferrate. Each investigation started by a thermodynamic study of different systems (M-O-Cl, M-S-Cl, M = metal) including the calculations of the standard free energy of Chlorination Reactions and phase stability diagrams of these systems. The kinetics of these Chlorination Reactions was studied by thermogravimetric analysis. The effects of total gas flow rate, temperature, individual reactant partial pressures, etc., on the Chlorination Reaction rate were investigated. Besides, experiments were also conducted in tubular furnaces. Several different qualitative and quantitative analyses methods were used to evaluate the selectivity and performance of the Chlorination processes. The results reported in this paper show the advantages of the Chlorination technology in terms of energy saving. selectivity of the processes,and recovery rate of valuable metals. They also demonstrate the possibility to treat lean raw materials, to improve the decontamination of wastes, to generate environmentally safer residues, to engineer new compounds, etc.
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Kinetics of Chlorination and carboChlorination of pure tantalum and niobium pentoxides
Metallurgical and Materials Transactions B, 1997Co-Authors: E. Allain, M. Djona, I. GaballahAbstract:Kinetics of Chlorination and carboChlorination of pure Nb_2O_5 and Ta_2O_5 were studied by thermogravimetric analysis between 385 °C and 1000 °C using Cl_2-N_2 and Cl_2-CO-N_2 gas mixtures. Standard free energy changes of the Reactions and phase stability diagrams of Nb-O-Cl and Ta-O-Cl systems were calculated. The Chlorination Reaction order, for both oxides, with respect to Cl_2 in the Cl_2-N_2 gas mixture was 0.82. The apparent activation energies ( E _ a ) for Nb_2O_5 Chlorination were 208 and 86 kJ/mole for temperatures lower and higher than 850 °C, respectively. The experimental data could be described by a shrinking sphere model between 700 °C and 1000 °C. The Chlorination mechanism, between 700 °C and 850 °C, was likely controlled by the chemical Reaction. For T > 850 °C, the overall Nb_2O_5 Chlorination rate was affected by the allotropic transformation of the Nb_2O_5 T form to M form. Between 925 °C and 1000 °C, E _ a for Ta_2O_5 Chlorination was 246 kJ/mole. In this case, the most appropriate model was also that of shrinking sphere suggesting that the Chlorination of Ta_2O_5 was controlled by the chemical Reaction. For both oxides, the carboChlorination Reaction order with respect to Cl_2+CO partial pressure, in the gas mixture, was about 2. The mathematical analysis of carboChlorination data indicates that Nb_2O_5 and Ta_2O_5 Reactions could be described by shrinking sphere or cylinder, respectively. Below 600 °C, the E _ a values of Nb_2O_5 and Ta_2O_5 carboChlorination were 74 and 110 kJ/mole, respectively. Chemical Reaction was probably the rate controlling step in both cases. An anomaly characterized by a decrease of the Reaction rates occurs in the Arrhenius plots between 600 °C and 800 °C. This anomaly could be attributed to the thermal decomposition of COCl_2 formed in situ during the carboChlorination.
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Kinetics of Chlorination and carboChlorination of lead sulfate
Thermochimica Acta, 1997Co-Authors: Nour-eddine Menad, Ndue Kanari, I. GaballahAbstract:The kinetics of Chlorination and carboChlorination of PbSO4 with Cl2 + N2 and Cl2 + CO + N2 gas mixtures has been studied using thermogravimetric measurements in the range 700–900°C. The Chlorination Reaction rate of PbSO4 with Cl2 + N2 increases with rise in the chlorine content in the gas mixture. The Reaction order is about 0.66 with respect to chlorine. The Chlorination rate of PbSO4 is controlled by a chemical Reaction mechanism with an apparent activation energy of about 174 kJ/mol. In the same temperature range, the apparent activation energy of the carboChlorination of lead sulfate by Cl2 + CO + N2 gas mixture is about 114 kJ/mol. The Reaction order is about 0.72 with respect to Cl2 + CO. The maximum Reaction rate is obtained by using a carbochlorinating gas mixture having a Cl2(Cl2 + CO) ratio equal to about 0.6.
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Kinetics of Chlorination and carboChlorination of molybdenum trioxide
Metallurgical and Materials Transactions B, 1995Co-Authors: M. Djona, E. Allain, I. GaballahAbstract:Kinetics of Chlorination of MoO_3 with Cl_2-air, Cl_2-N_2, and Cl_2-CO-N_2 gas mixtures have been studied by nonisothermal and isothermal thermogravimetric measurements, between ambient temperature and 900 °C. Between 500 °C and 700 °C, the Chlorination Reaction of MoO_3 with Cl_2-N_2 gas mixture has an apparent activation energy of about 165 kJ/mole, reflecting that a chemical Reaction is the rate-controlling step. The Reaction order with respect to Cl_2 partial pressure is about 0.75. The apparent activation energy for carboChlorination with Cl_2-CO-N_2 gas mixture is about 83 kJ/mole, between 400 °C and 650 °C. The carboChlorination of MoO_3 was controlled by the chemical Reaction, probably affected by the pore diffusion regime. The maximum Reaction rate is obtained by using a Cl_2-CO-N_2 gas mixture, having a Cl_2/CO volume ratio equal to about 1. The total apparent Reaction order with respect to Cl_2 + CO in Cl_2-CO-N_2 gas mixture is about 1.5 for a Cl_2/CO ratio equal to 1.
Kweon Ho Kang - One of the best experts on this subject based on the ideXlab platform.
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a tga study on the Chlorination Reaction kinetics of zircaloy 4 cladding hulls
Journal of Nuclear Materials, 2015Co-Authors: Min Ku Jeon, Yong Taek Choi, Kweon Ho Kang, Geun Il ParkAbstract:Abstract The Chlorination Reaction kinetics of Zircaloy-4 cladding hulls were investigated using a home-made thermogravimetric analysis for a hull Chlorination (TGA-HC) system. The reproducibility of the TGA-HC system was verified by repeated measurements at an identical condition, which showed only 6.6% of maximum difference. The effect of total flow rate ( Q ) was investigated for Q of 120 and 240 mL/min, and it was revealed that the Reaction rate is not influenced in this condition. Using the Sharp–Hancock plot, the volumetric contraction model was identified as the most suitable model for the Zircaloy-4 Chlorination Reaction. The influence of chlorine partial pressure was studied at 9.21, 16.9, and 23.4 kPa of Cl 2 partial pressure conditions, and it was identified that the Reaction rate is proportional to the chlorine partial pressure on the order of (0.669). The effect of Reaction temperature was investigated for 300–450 °C, and it was revealed that the Chlorination Reaction exhibits an activation energy of 26.2 kJ/mol. Using the experimental and fitting results, the Reaction rate equation for the Zircaloy-4 Chlorination Reaction was achieved, but the equation was valid only until the conversion fraction ( α ) reaches up to (0.60). When α is higher than 0.60, the volumetric contraction model was not applicable. A second-order Reaction rate equation was suggested for the 0.6 α region, although it needs further investigation.
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Chlorination Reaction kinetics of CsI under cladding hull waste treatment condition: a TGA study
Journal of Radioanalytical and Nuclear Chemistry, 2015Co-Authors: Min Ku Jeon, Yong Taek Choi, Chang Hwa Lee, Deok Yoon Kang, Kweon Ho Kang, Hwan Seo Park, Do-hee AhnAbstract:The Reaction between cesium iodide (CsI) and chlorine gas was quantitatively investigated using a thermo-gravimetric analysis system. A comparison between calculated and experimental results on the chlorine molar flow rate revealed that the Reaction lies within the gas phase diffusion limited region under the condition of this work. Using the experimental data, the second-order nucleation and growth model was identified as the best geometry function to describe the morphological changes of CsI during the Chlorination Reaction. Combining the gas phase diffusion equation and geometry function, a Reaction rate equation was proposed for the Reaction between CsI and Cl2.
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Chlorination Reaction behavior of zircaloy 4 hulls a preliminary study on the effect of the oxidation process on the Reaction rate
Journal of the Nuclear Fuel Cycle and Waste Technology, 2013Co-Authors: Min Ku Jeon, Yong Taek Choi, Chang Hwa Lee, Kweon Ho Kang, Chul Min Heo, You Lee Lee, Geun Il ParkAbstract:Reaction period of 0 – 2 h. The amount of Reaction residue increased from 0.95 to 1.65wt% of initial weights in the fresh and Zry-500-10 (Zry-4 hulls oxidized at 500 o C for 10 h under an air atmosphere) hulls, respectively. The purity of the recovered Zr was identical at 99.61wt% for the fresh Zry-4 and Zry-500-10 hulls. Quantitative analysis of the Chlorination Reaction rate was performed by varying the Reaction time from 0.5 to 1.0, 2.0, and 4.0 h. The fitting results showed that the relationship between weight loss and Reaction time can be interpreted by a linear line with a slope of 23.35wt%/h for the fresh Zry-4 case, while two linear lines were necessary to fit the results of Zry-500-10. In addition, the slope values were 17.12 and 27.16wt%/h for (0 – 20) and (20 – 100)wt% loss regions, respectively.
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simulation of radioactivation and Chlorination Reaction behavior for zircaloy 4 and zirlo cladding hull wastes
Journal of Radioanalytical and Nuclear Chemistry, 2012Co-Authors: Min Ku Jeon, Chang Hwa Lee, Kweon Ho Kang, Chang Je Park, Geun Il ParkAbstract:Radioactivation of Zircaloy-4 (Zry-4) and Zirlo cladding hulls after 55 GWD/tU burn-up and 10 years of cooling was simulated using the ORIGEN-S code. The simulation results revealed that 125Sb and 60Co are major contributors of both radioactivity and decay heat in the case of the Zry-4 hulls. For the Zirlo hulls, 93mNb and 125Sb consisted 82.2% of radioactivity while 125Sb and 60Co emitted 77.9% of decay heat. Although the radioactivity between the Zry-4 (1.17 Ci for 1 kg of fresh Zry-4) and Zirlo (1.38 Ci for 1 kg of fresh Zirlo) hulls was not significantly different, decay heat of the activated Zry-4 hulls (8.58 mW) was much larger than 1.62 mW of the activated Zirlo hulls. This gap might have come from the different major constituents of Zry-4 (Zr, Sn, Fe, and Cr) and Zirlo (Zr, Sn, Nb, and Fe) resulting in different radioactive nuclides after radioactivation. Chlorination Reaction behavior of the activated Zry-4 and Zirlo hulls was performed using the HSC chemistry code. Constituents of recovered ZrCl4 were investigated via changes of Gibbs free energy and boiling points of resulting chlorides. The calculation results suggested that radioactivity and decay heat might decrease by 49.0 and 81.8%, respectively, in the ZrCl4 recovered from the activated Zry-4 hulls. In the case of Zirlo, it was expected that radioactivity and decay heat might decrease by 11.6 and 13.0%, respectively, after the Chlorination Reaction. Effect of cooling time on radioactivity and decay heat was also investigated.
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effect of oxidation conditions on Chlorination Reaction of zircaloy 4 hulls
Journal of Nuclear Materials, 2012Co-Authors: Min Ku Jeon, Chang Hwa Lee, Kweon Ho Kang, Jae Hwan Yang, Chul Min Heo, Geun Il ParkAbstract:Abstract The effect of oxidation conditions on the Chlorination Reaction behavior was investigated by using Zircaloy-4 (Zry-4) hulls oxidized at various conditions. When the hulls were oxidized at 500, 600, and 700 °C for 5 h, decrease of reactant mass after the Chlorination Reaction at 380 °C for 3 h was 41.6, 26.0, and 0.0 wt.%, respectively, while that of fresh Zry-4 hulls was 54.1 wt.%. Surface analysis results revealed that the oxidation state of Zr is significantly dependent on the oxidation temperature. The effect of oxidation time was also investigated for the Zry-4 hulls oxidized at 500 and 700 °C up to 24 h. Based on the experimental results, it was concluded that the Chlorination method is applicable to the Zry-4 hulls oxidized at 500 °C without removal of the surface oxide layers, while a pretreatment is required to recover Zr from the hulls oxidized at 700 °C.
Chang Hwa Lee - One of the best experts on this subject based on the ideXlab platform.
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Chlorination Reaction kinetics of CsI under cladding hull waste treatment condition: a TGA study
Journal of Radioanalytical and Nuclear Chemistry, 2015Co-Authors: Min Ku Jeon, Yong Taek Choi, Chang Hwa Lee, Deok Yoon Kang, Kweon Ho Kang, Hwan Seo Park, Do-hee AhnAbstract:The Reaction between cesium iodide (CsI) and chlorine gas was quantitatively investigated using a thermo-gravimetric analysis system. A comparison between calculated and experimental results on the chlorine molar flow rate revealed that the Reaction lies within the gas phase diffusion limited region under the condition of this work. Using the experimental data, the second-order nucleation and growth model was identified as the best geometry function to describe the morphological changes of CsI during the Chlorination Reaction. Combining the gas phase diffusion equation and geometry function, a Reaction rate equation was proposed for the Reaction between CsI and Cl2.
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Chlorination Reaction behavior of zircaloy 4 hulls a preliminary study on the effect of the oxidation process on the Reaction rate
Journal of the Nuclear Fuel Cycle and Waste Technology, 2013Co-Authors: Min Ku Jeon, Yong Taek Choi, Chang Hwa Lee, Kweon Ho Kang, Chul Min Heo, You Lee Lee, Geun Il ParkAbstract:Reaction period of 0 – 2 h. The amount of Reaction residue increased from 0.95 to 1.65wt% of initial weights in the fresh and Zry-500-10 (Zry-4 hulls oxidized at 500 o C for 10 h under an air atmosphere) hulls, respectively. The purity of the recovered Zr was identical at 99.61wt% for the fresh Zry-4 and Zry-500-10 hulls. Quantitative analysis of the Chlorination Reaction rate was performed by varying the Reaction time from 0.5 to 1.0, 2.0, and 4.0 h. The fitting results showed that the relationship between weight loss and Reaction time can be interpreted by a linear line with a slope of 23.35wt%/h for the fresh Zry-4 case, while two linear lines were necessary to fit the results of Zry-500-10. In addition, the slope values were 17.12 and 27.16wt%/h for (0 – 20) and (20 – 100)wt% loss regions, respectively.
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simulation of radioactivation and Chlorination Reaction behavior for zircaloy 4 and zirlo cladding hull wastes
Journal of Radioanalytical and Nuclear Chemistry, 2012Co-Authors: Min Ku Jeon, Chang Hwa Lee, Kweon Ho Kang, Chang Je Park, Geun Il ParkAbstract:Radioactivation of Zircaloy-4 (Zry-4) and Zirlo cladding hulls after 55 GWD/tU burn-up and 10 years of cooling was simulated using the ORIGEN-S code. The simulation results revealed that 125Sb and 60Co are major contributors of both radioactivity and decay heat in the case of the Zry-4 hulls. For the Zirlo hulls, 93mNb and 125Sb consisted 82.2% of radioactivity while 125Sb and 60Co emitted 77.9% of decay heat. Although the radioactivity between the Zry-4 (1.17 Ci for 1 kg of fresh Zry-4) and Zirlo (1.38 Ci for 1 kg of fresh Zirlo) hulls was not significantly different, decay heat of the activated Zry-4 hulls (8.58 mW) was much larger than 1.62 mW of the activated Zirlo hulls. This gap might have come from the different major constituents of Zry-4 (Zr, Sn, Fe, and Cr) and Zirlo (Zr, Sn, Nb, and Fe) resulting in different radioactive nuclides after radioactivation. Chlorination Reaction behavior of the activated Zry-4 and Zirlo hulls was performed using the HSC chemistry code. Constituents of recovered ZrCl4 were investigated via changes of Gibbs free energy and boiling points of resulting chlorides. The calculation results suggested that radioactivity and decay heat might decrease by 49.0 and 81.8%, respectively, in the ZrCl4 recovered from the activated Zry-4 hulls. In the case of Zirlo, it was expected that radioactivity and decay heat might decrease by 11.6 and 13.0%, respectively, after the Chlorination Reaction. Effect of cooling time on radioactivity and decay heat was also investigated.
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effect of oxidation conditions on Chlorination Reaction of zircaloy 4 hulls
Journal of Nuclear Materials, 2012Co-Authors: Min Ku Jeon, Chang Hwa Lee, Kweon Ho Kang, Jae Hwan Yang, Chul Min Heo, Geun Il ParkAbstract:Abstract The effect of oxidation conditions on the Chlorination Reaction behavior was investigated by using Zircaloy-4 (Zry-4) hulls oxidized at various conditions. When the hulls were oxidized at 500, 600, and 700 °C for 5 h, decrease of reactant mass after the Chlorination Reaction at 380 °C for 3 h was 41.6, 26.0, and 0.0 wt.%, respectively, while that of fresh Zry-4 hulls was 54.1 wt.%. Surface analysis results revealed that the oxidation state of Zr is significantly dependent on the oxidation temperature. The effect of oxidation time was also investigated for the Zry-4 hulls oxidized at 500 and 700 °C up to 24 h. Based on the experimental results, it was concluded that the Chlorination method is applicable to the Zry-4 hulls oxidized at 500 °C without removal of the surface oxide layers, while a pretreatment is required to recover Zr from the hulls oxidized at 700 °C.
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effect of chlorinating reagents on zr recovery from zircaloy 4 hull wastes Reaction behavior simulation by using the hsc code
Journal of Radioanalytical and Nuclear Chemistry, 2012Co-Authors: Min Ku Jeon, Kweon Ho Kang, Geun Il Park, Chang Hwa LeeAbstract:Chlorination Reaction behavior of Zircaloy-4 (Zry-4) was simulated by using the HSC code for three different chlorinating reagents of Cl2, HCl, and CCl4. Four major components (Zr, Sn, Fe, and Cr) of Zry-4 and their oxides which were produced during an oxidative declad- ding process were considered for the theoretical calcula- tion. The simulation results revealed that Cl2 might convert metallic Zr, Sn, Fe, and Cr into their chloride forms, while oxides might not react with Cl2 at 380 C. When HCl was employed as the chlorinating reagent, it was suggested that metallic Zr, Sn, and Cr might react with HCl while Fe and oxides might not. In the case of CCl4, it was shown that CCl4 could react with all of the metallic and oxide com- ponents to produce most amount of ZrCl4 when compared with Cl2 and HCl cases. Reaction behavior of the chlori- nating reagents with residual spent nuclear fuel constitu- ents (U3O8, MoO3, Pd, BaO, Y2O3, SrO, Rh2O3, RhO2, La2O3, CeO2, and Nd2O3) was also performed, and it was revealed that Cl2 and HCl might produce (PdCl2, BaCl2, SrCl2, RhCl3, LaCl3, and NdCl3) and (BaCl2, YCl3, SrCl2, RhCl3, LaCl3, and NdCl3), respectively. Although these by-products are produced, it was suggested that highly pure ZrCl4(g) which contains FeCl3(g) and SnCl4(g) as impu- rities might be recovered when Cl2 or HCl is employed as a chlorinating reagent because other by-products have higher boiling point than the Reaction temperature of this study (380 C). On the other hand, the theoretical calculation results showed that CCl4 might react with all the residual spent fuel constituents to produce additional gaseous impurities of UCl6 and MoCl5 to reduce the purity of ZrCl4 product.