Pub Date : 2021-07-01DOI: 10.4236/wjnst.2021.113010
I. Konaté, Djagoury Koudou
Objective: The aim of our work is to study radiological practices in C?te d’Ivoire regarding the examination of the frontal chest in order to optimize the dose received by patients. Materials and Methods: The work was carried out in 11 of the most frequented radiology centers and involved 330 patients. The equipment used in addition to those that can be found in an X-ray room is the DAP-meter. Using the DAP-meter, we measured the Dose in the air (Dair) then we calculated the Entrance Surface Dose (De). Results: We have by the statistical method of the 75th percentile determined the Diagnostic Reference Level (DRL): 0.28 ± 0.03 mGy and by the arithmetic average, the average of the entrance surface dose (Dem): 0.23 ± 0.03 mGy. Since the DRL is lower than the Dem, the dose is said to be optimized. However by comparing the DRL of our work to the DRL values obtained in other countries, we can say that efforts can be made to further protect patients from unnecessary doses. This involves increasing the voltage, decreasing the load, increasing the detector focal point distance, and increasing additional filtration.
{"title":"Study of Radiological Practices in Côte d’Ivoire: Case of the Frontal Chest Examination","authors":"I. Konaté, Djagoury Koudou","doi":"10.4236/wjnst.2021.113010","DOIUrl":"https://doi.org/10.4236/wjnst.2021.113010","url":null,"abstract":"Objective: The aim of our work is to study radiological practices in C?te d’Ivoire regarding the examination of the frontal chest in order to optimize the dose received by patients. Materials and Methods: The work was carried out in 11 of the most frequented radiology centers and involved 330 patients. The equipment used in addition to those that can be found in an X-ray room is the DAP-meter. Using the DAP-meter, we measured the Dose in the air (Dair) then we calculated the Entrance Surface Dose (De). Results: We have by the statistical method of the 75th percentile determined the Diagnostic Reference Level (DRL): 0.28 ± 0.03 mGy and by the arithmetic average, the average of the entrance surface dose (Dem): 0.23 ± 0.03 mGy. Since the DRL is lower than the Dem, the dose is said to be optimized. However by comparing the DRL of our work to the DRL values obtained in other countries, we can say that efforts can be made to further protect patients from unnecessary doses. This involves increasing the voltage, decreasing the load, increasing the detector focal point distance, and increasing additional filtration.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48506772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-01DOI: 10.4236/wjnst.2021.113009
Arif Jahan Sarawer, M. Hoq, M. A. Khae, Mahobul Islam, M. M. Rahman, M. T. Chowdhury, M. M. Rahman
The assessment of the radiological concentration of 134Cs and 137Cs owing to hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh is presented here in this work. The concentration of 134Cs and 137Cs was estimated in different pathways consisting of the ingestion of plants, milk, and meat. The highest air concentration has been determined at 65 m distance from the core of the reactor. The maximum concentration passed off without delay simply after the accident in various directions. Local meteorological information such as average wind velocity and wind frequency were analyzed. Considering all directions, the highest concentration has been observed in the “S” direction. The concentrations of 134Cs and 137Cs were determined in ground, vegetation, milk and meat. The concentration of 137Cs is investigated to be higher than the 134Cs. The concentration of 134Cs and 137Cs was found to be lower in vegetation, milk, and meat than that of ground concentration. Overall, in this study, the concentration in meat has been investigated to be lower. In case of a reactor accident, the concentration assessment due to the ingestion of vegetables, milk, and meat will be a valuable guide for insuring radiological protection across the research reactor at AERE, Savar, Bangladesh.
本文介绍了孟加拉国萨瓦尔AERE TRIGA Mark II研究堆假想事故引起的134Cs和137Cs放射性浓度的评估。134Cs和137Cs的浓度是通过摄入植物、牛奶和肉类等不同途径估算的。最高空气浓度已在距离反应堆堆芯65米处确定。事故发生后，最大浓度在各个方向上毫不拖延地消失了。分析了当地的平均风速和风频等气象信息。考虑到所有方向，在“S”方向观察到最高浓度。测定了土壤、植被、牛奶和肉类中134Cs和137Cs的浓度。137Cs的浓度被研究为高于134Cs。134Cs和137Cs在植被、牛奶和肉类中的浓度低于地面浓度。总的来说，在这项研究中，肉类中的浓度被调查为较低。在反应堆事故的情况下，由于摄入蔬菜、牛奶和肉类而进行的浓度评估将是确保孟加拉国萨瓦尔AERE研究反应堆辐射防护的宝贵指南。
{"title":"Radiological Concentration Distribution of 134Cs and 137Cs Due to a Hypothetical Accident of TRIGA Research Reactor","authors":"Arif Jahan Sarawer, M. Hoq, M. A. Khae, Mahobul Islam, M. M. Rahman, M. T. Chowdhury, M. M. Rahman","doi":"10.4236/wjnst.2021.113009","DOIUrl":"https://doi.org/10.4236/wjnst.2021.113009","url":null,"abstract":"The assessment of the radiological concentration of 134Cs and 137Cs owing to hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh is presented here in this work. The concentration of 134Cs and 137Cs was estimated in different pathways consisting of the ingestion of plants, milk, and meat. The highest air concentration has been determined at 65 m distance from the core of the reactor. The maximum concentration passed off without delay simply after the accident in various directions. Local meteorological information such as average wind velocity and wind frequency were analyzed. Considering all directions, the highest concentration has been observed in the “S” direction. The concentrations of 134Cs and 137Cs were determined in ground, vegetation, milk and meat. The concentration of 137Cs is investigated to be higher than the 134Cs. The concentration of 134Cs and 137Cs was found to be lower in vegetation, milk, and meat than that of ground concentration. Overall, in this study, the concentration in meat has been investigated to be lower. In case of a reactor accident, the concentration assessment due to the ingestion of vegetables, milk, and meat will be a valuable guide for insuring radiological protection across the research reactor at AERE, Savar, Bangladesh.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49293954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-12DOI: 10.4236/WJNST.2021.112008
A. Agbo, K. Djagouri, J. Brigui, Konin Pierre-Claver Kakou
Eight water bottles from Ebrie lagoon with pollution potency were studied using nuclear chemistry technique and Energy dispersive X-ray fluorescence. This pollution is characterized by pH and conductivity parameters, concentrations average in mg/L of metals such Fe (0.731), Mn (0.345), Cr (0.070), Cu (0.014) and concentrations of nutrients known to be pollutants and toxic for living or-ganisms. These heavy metals are dangerous to the lives, the local inhabitants and also a threat to aquatic life since this water is essential for the economical town, Abidjan. According to the Manganese concentration average (0.345 mg) values that higher than WHO (0.05 mg) value, the main likely source of pollu-tants is anthropogenic, industrial and agricultural. This study also shows the use of materials and lubricants near the lagoon that pollute this water.
{"title":"Determination of Element Levels of Lagoon from Townships near Cocody City Abidjan Côte D’Ivoire Using Energy Dispersive X-Ray Fluorescence","authors":"A. Agbo, K. Djagouri, J. Brigui, Konin Pierre-Claver Kakou","doi":"10.4236/WJNST.2021.112008","DOIUrl":"https://doi.org/10.4236/WJNST.2021.112008","url":null,"abstract":"Eight water bottles from Ebrie lagoon with pollution potency were studied using nuclear chemistry technique and Energy dispersive X-ray fluorescence. This pollution is characterized by pH and conductivity parameters, concentrations average in mg/L of metals such Fe (0.731), Mn (0.345), Cr (0.070), Cu (0.014) and concentrations of nutrients known to be pollutants and toxic for living or-ganisms. These heavy metals are dangerous to the lives, the local inhabitants and also a threat to aquatic life since this water is essential for the economical town, Abidjan. According to the Manganese concentration average (0.345 mg) values that higher than WHO (0.05 mg) value, the main likely source of pollu-tants is anthropogenic, industrial and agricultural. This study also shows the use of materials and lubricants near the lagoon that pollute this water.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":"11 1","pages":"109-118"},"PeriodicalIF":0.0,"publicationDate":"2021-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46350141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.4236/WJNST.2021.112006
R. Rabi, L. Oufni, Khamiss Cheikh, El-Houcine Youssoufi, H. Badry, Y. Errami
Human exposure to radon inside different parts of the house has become a great concern. In this study, the distribution of radon and its decay inside the shower will be numerically investigated. In fact, the radon concentration in water is measured through the use of AlphaGUARD. They are used as an input for CFD simulation. The numerical results proved that temperature and humidity have significant impacts on both radon content and distribution. Also, the equilibrium factor variations between radon and its progeny with the temperature and relative humidity were carefully looked at. The equivalent doses due to 218Po and 214Po were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of air inside the shower. The annual effective dose due to radon short lived decay from the inhalation of air inside the shower by the members of the public was also investigated.
{"title":"Modeling of Radon and Its Short-Lived Decay Products during Showering: Dose to Adult Members of the Public","authors":"R. Rabi, L. Oufni, Khamiss Cheikh, El-Houcine Youssoufi, H. Badry, Y. Errami","doi":"10.4236/WJNST.2021.112006","DOIUrl":"https://doi.org/10.4236/WJNST.2021.112006","url":null,"abstract":"Human exposure to radon inside different parts of the house has become a great concern. In this study, the distribution of radon and its decay inside the shower will be numerically investigated. In fact, the radon concentration in water is measured through the use of AlphaGUARD. They are used as an input for CFD simulation. The numerical results proved that temperature and humidity have significant impacts on both radon content and distribution. Also, the equilibrium factor variations between radon and its progeny with the temperature and relative humidity were carefully looked at. The equivalent doses due to 218Po and 214Po were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of air inside the shower. The annual effective dose due to radon short lived decay from the inhalation of air inside the shower by the members of the public was also investigated.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":"11 1","pages":"84-99"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49326950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.4236/WJNST.2021.112005
Baoling Zhang, Xue Su, Chongyang Li, Junwei Zhang
Dislocation and grain boundary have great influence on helium behavior in materials. In this paper, the helium bubble coalescence in titanium with dislocations was simulated using molecular dynamics method. The results show that, when the second helium bubble nucleates near the slip plane, it grows toward the first helium bubble which lies at the dislocation core till they coalesce with each other. However, it is not easy for the coalescence to occur if the two helium bubbles lie in different atomic layers in (001) plane. If the second helium bubble is nucleated on the side of the slip plane with full atomic layers, the second helium bubble growth could lead to the movement of the first helium bubble toward the other sides of the slip plane. The growth rate and direction of the second helium bubble are closely related to the pressure around it.
{"title":"Study on Helium Bubble Coalescence in Titanium with Dislocations","authors":"Baoling Zhang, Xue Su, Chongyang Li, Junwei Zhang","doi":"10.4236/WJNST.2021.112005","DOIUrl":"https://doi.org/10.4236/WJNST.2021.112005","url":null,"abstract":"Dislocation and grain boundary have great influence on helium behavior in materials. In this paper, the helium bubble coalescence in titanium with dislocations was simulated using molecular dynamics method. The results show that, when the second helium bubble nucleates near the slip plane, it grows toward the first helium bubble which lies at the dislocation core till they coalesce with each other. However, it is not easy for the coalescence to occur if the two helium bubbles lie in different atomic layers in (001) plane. If the second helium bubble is nucleated on the side of the slip plane with full atomic layers, the second helium bubble growth could lead to the movement of the first helium bubble toward the other sides of the slip plane. The growth rate and direction of the second helium bubble are closely related to the pressure around it.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":"11 1","pages":"73-83"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45805074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-01DOI: 10.4236/WJNST.2021.112007
Jianyong Zhang, X. Mo, Xiao Cai
High purity germanium detectors have important applications in many fields. Detector’s performance deteriorated significantly due to radiation of neutron. The annealing of damaged HPGe detector is expounded in this monograph. The experiment results indicate that raising the temperature to 70°C for five days, the restoration efficiency can reach 90%.
{"title":"Study of Annealing the Damaged HPGe Detector","authors":"Jianyong Zhang, X. Mo, Xiao Cai","doi":"10.4236/WJNST.2021.112007","DOIUrl":"https://doi.org/10.4236/WJNST.2021.112007","url":null,"abstract":"High purity germanium detectors have important applications in many fields. Detector’s performance deteriorated significantly due to radiation of neutron. The annealing of damaged HPGe detector is expounded in this monograph. The experiment results indicate that raising the temperature to 70°C for five days, the restoration efficiency can reach 90%.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":"11 1","pages":"100-108"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43687463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-29DOI: 10.4236/WJNST.2021.111003
Ranjana Nath-M
Radiopharmaceuticals are used in nuclear medicine for diagnostic or therapeutic acts. The short decay half-lives of medical radioisotopes, especially those used for diagnostics, imply that they should be produced continuously and transported as quickly as possible to the medical units where they are used. Neutron-rich medical radioisotopes are generally produced in research reactors, like technetium-99m, lutetium-177, holmium-166 and iodine-131. On the other hand, proton-rich radioisotopes are produced via reactions with charged particles from accelerators like fluorine-18, gallium-67, iodine-123 and thallium-201. Beside this, innovative nuclear reactors are advocated as solutions to the issues of nuclear waste production and proliferation threats. Fast neutron, thorium-cycle and accelerator-driven subcritical (ADS) reactors are some of the most promising of them, proposed as safer fuel breeders and “waste burners”. This article examines the use of a fast thorium-cycle ADS with liquid lead-bismuth eutectic coolant for the production of molybdenum-99/technetium-99m and lutetium-177. Burnup simulation has been made with the Monte-Carlo (MC) code SERPENT. It is demonstrated that MC codes can advantageously be used to determine the optimal irradiation time for a given radioisotope in a realistic reactor core. It is also shown that fast thorium-cycle ADS is an economical option for the production of medical radioisotopes.
{"title":"Simulating the Production of Medical Radioisotopes in a Fast Thorium-Cycle ADS with SERPENT","authors":"Ranjana Nath-M","doi":"10.4236/WJNST.2021.111003","DOIUrl":"https://doi.org/10.4236/WJNST.2021.111003","url":null,"abstract":"Radiopharmaceuticals are used in nuclear medicine for diagnostic or therapeutic acts. The short decay half-lives of medical radioisotopes, especially those used for diagnostics, imply that they should be produced continuously and transported as quickly as possible to the medical units where they are used. Neutron-rich medical radioisotopes are generally produced in research reactors, like technetium-99m, lutetium-177, holmium-166 and iodine-131. On the other hand, proton-rich radioisotopes are produced via reactions with charged particles from accelerators like fluorine-18, gallium-67, iodine-123 and thallium-201. Beside this, innovative nuclear reactors are advocated as solutions to the issues of nuclear waste production and proliferation threats. Fast neutron, thorium-cycle and accelerator-driven subcritical (ADS) reactors are some of the most promising of them, proposed as safer fuel breeders and “waste burners”. This article examines the use of a fast thorium-cycle ADS with liquid lead-bismuth eutectic coolant for the production of molybdenum-99/technetium-99m and lutetium-177. Burnup simulation has been made with the Monte-Carlo (MC) code SERPENT. It is demonstrated that MC codes can advantageously be used to determine the optimal irradiation time for a given radioisotope in a realistic reactor core. It is also shown that fast thorium-cycle ADS is an economical option for the production of medical radioisotopes.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":"11 1","pages":"43-64"},"PeriodicalIF":0.0,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41734063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-08DOI: 10.4236/WJNST.2021.111004
Xenofontos Thalia, Savva Panayiota, M. Varvayanni, J. Maillard, J. Silva, N. Catsaros
One of the most important safety parameters taken into consideration during the design and actual operation of a nuclear reactor is its control rods adjustment to reach criticality. Concerning the conventional nuclear systems, the specification of their rods’ position through the utilization of neutronics codes, deterministic or stochastic, is considered nowadays trivial. However, innovative nuclear reactor concepts such as the Accelerator Driven Systems require sophisticated simulation capabilities of the stochastic neutronics codes since they combine high energy physics, for the spallation-produced neutrons, with classical nuclear technology. ANET (Advanced Neutronics with Evolution and Thermal hydraulic feedback) is an under development stochastic neutronics code, able to cover the broad neutron energy spectrum involved in ADS systems and therefore capable of simulating conventional and hybrid nuclear reactors and calculating important reactor parameters. In this work, ANETS’s reliability to calculate the effective multiplication factor for three core configurations containing control rods of the Kyoto University Critical Assembly, an operating ADS, is examined. The ANET results successfully compare with results produced by well-established stochastic codes such as MCNP6.1.
在核反应堆的设计和实际运行过程中，最重要的安全参数之一是调整控制棒以达到临界状态。关于常规核系统，通过使用确定性或随机性的中子学代码来指定其棒的位置，如今被认为是微不足道的。然而，加速器驱动系统等创新核反应堆概念需要复杂的随机中子学代码模拟能力，因为它们将散裂产生的中子的高能物理与经典核技术相结合。ANET（Advanced Neutronics with Evolution and Thermal hydraulic feedback）是一个正在开发的随机中子学代码，能够覆盖ADS系统中涉及的宽中子能谱，因此能够模拟常规和混合核反应堆并计算重要的反应堆参数。在这项工作中，检验了ANETS计算包含京都大学临界组件控制棒的三个核心配置的有效倍增因子的可靠性。ANET的结果成功地与诸如MCNP6.1之类的公认随机代码产生的结果进行了比较。
{"title":"Criticality Search of an Accelerator Driven System Using the ANET Code","authors":"Xenofontos Thalia, Savva Panayiota, M. Varvayanni, J. Maillard, J. Silva, N. Catsaros","doi":"10.4236/WJNST.2021.111004","DOIUrl":"https://doi.org/10.4236/WJNST.2021.111004","url":null,"abstract":"One of the most important safety parameters taken into consideration during the design and actual operation of a nuclear reactor is its control rods adjustment to reach criticality. Concerning the conventional nuclear systems, the specification of their rods’ position through the utilization of neutronics codes, deterministic or stochastic, is considered nowadays trivial. However, innovative nuclear reactor concepts such as the Accelerator Driven Systems require sophisticated simulation capabilities of the stochastic neutronics codes since they combine high energy physics, for the spallation-produced neutrons, with classical nuclear technology. ANET (Advanced Neutronics with Evolution and Thermal hydraulic feedback) is an under development stochastic neutronics code, able to cover the broad neutron energy spectrum involved in ADS systems and therefore capable of simulating conventional and hybrid nuclear reactors and calculating important reactor parameters. In this work, ANETS’s reliability to calculate the effective multiplication factor for three core configurations containing control rods of the Kyoto University Critical Assembly, an operating ADS, is examined. The ANET results successfully compare with results produced by well-established stochastic codes such as MCNP6.1.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":"9 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41260249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-08DOI: 10.4236/WJNST.2021.111001
P. Fleming, Pedro Orrego, F. Pinilla
The rare earth elements (REE) include the group of 15 lanthanides, scandium and yttrium and have diverse applications in technological and nuclear areas. The existence of REE in massive solid mining wastes generated in leaching processes of copper minerals in the Atacama region of Chile generates the possibility of creating added value to the treatment of this type of waste and supporting the development of a circular economy, generating a useful by-product in different industries. In order to know the behavior of these elements present in the solid carrier waste, a leaching process was carried out by using two agents separately, corresponding to hydrochloric and nitric acid. The technical feasibility to recover REE from carrier tail was demonstrated, the best leaching agent for these elements being a hydrochloric solution, obtaining a maximum recovery efficiency of 64.5%, for an acid concentration: 3M, temperature: 40°C and (liquid/solid) ratio: 4. Lanthanum and cerium present the best individual recoveries compared to the other REE, with a maximum efficiency for a hydrochloric solution of 75.7% and 70.0%, respectively. The interaction of operational parameters that most influence the REE recovery corresponds to the temperature and the (liquid/solid) ratio. After 4 hours of leaching, REE recovery efficiencies remain practically constant. Acid consumptions correspond to 11 (kg HCl/ton mining tail) and 29 (kg HNO3/ton mining tail). The highest amount recovery ratios of these elements correspond to 0.355 and 0.224 (kg REE/ton mining tail), for hydrochloric and nitric solutions, respectively. These results influence the types of reagents and parameters to be studied in the following stages of the global process.
{"title":"Recovery of Rare Earth Elements Present in Mining Tails, by Leaching with Nitric and Hydrochloric Solutions","authors":"P. Fleming, Pedro Orrego, F. Pinilla","doi":"10.4236/WJNST.2021.111001","DOIUrl":"https://doi.org/10.4236/WJNST.2021.111001","url":null,"abstract":"The rare earth elements (REE) include the group of 15 lanthanides, scandium and yttrium and have diverse applications in technological and nuclear areas. The existence of REE in massive solid mining wastes generated in leaching processes of copper minerals in the Atacama region of Chile generates the possibility of creating added value to the treatment of this type of waste and supporting the development of a circular economy, generating a useful by-product in different industries. In order to know the behavior of these elements present in the solid carrier waste, a leaching process was carried out by using two agents separately, corresponding to hydrochloric and nitric acid. The technical feasibility to recover REE from carrier tail was demonstrated, the best leaching agent for these elements being a hydrochloric solution, obtaining a maximum recovery efficiency of 64.5%, for an acid concentration: 3M, temperature: 40°C and (liquid/solid) ratio: 4. Lanthanum and cerium present the best individual recoveries compared to the other REE, with a maximum efficiency for a hydrochloric solution of 75.7% and 70.0%, respectively. The interaction of operational parameters that most influence the REE recovery corresponds to the temperature and the (liquid/solid) ratio. After 4 hours of leaching, REE recovery efficiencies remain practically constant. Acid consumptions correspond to 11 (kg HCl/ton mining tail) and 29 (kg HNO3/ton mining tail). The highest amount recovery ratios of these elements correspond to 0.355 and 0.224 (kg REE/ton mining tail), for hydrochloric and nitric solutions, respectively. These results influence the types of reagents and parameters to be studied in the following stages of the global process.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48384644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-08DOI: 10.4236/WJNST.2021.111002
T. Takeda, Y. Wada, Y. Sibamoto
Many experiments have been conducted on accidents and transients of pressurized water reactor (PWR) employing the rig of safety assessment/large-scale test facility (ROSA/LSTF). Recent research activities concerned with the OECD/NEA international joint projects included experimental investigation via the ROSA and ROSA-2 Projects, and counterpart testing with thermal-hydraulic integral test facilities under collaboration of the PKL-2, PKL-3, ATLAS, and ATLAS-2 Projects. Major results of the related integral effect tests (IETs) with the LSTF were reviewed to experimentally identify thermal-hydraulic phenomena involved, regarding the PWR accident sequences in accordance with the new regulatory requirements for the Japanese light-water nuclear power plants. Future separate effect test using the LSTF is planned to simulate loss of emergency core cooling system (ECCS) recirculation functions in a large-break loss-of-coolant accident (LOCA). Key results of the recent IETs utilizing the LSTF and future plans were presented relevant to multiple steam generator tube rupture accident with recovery operation, small-break LOCA with accident management measure on core exit temperature reliability, and small-break LOCA with thermal stratification under cold water injection from ECCS into cold legs. Also, main outcomes of the LSTF IETs were indicated for wide spectrum LOCA with core uncovery and anticipated transient without scram following small-break LOCA under totally failed high-pressure injection system.
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