• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.3
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• pp.179-189
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• 2014

Pyroprocessing has been developed for the purpose of resolving the current spent nuclear fuel management issue and enhancing the recycle of valuable resources. An electrolytic reduction of the pyroprocessing is a process to reduce oxides into metals using LiCl as an electrolyte and requires a post-treatment process due to the inclusion of residual salt in porous metal products. A vacuum distillation has been adopted for various molten salt systems and could be applied to the post-treatment process of the electrolytic reduction. The residual salt in the metal products includes LiCl, alkali chlorides, and alkaline earth chlorides. In this paper, vapor pressures of chlorides have been estimated and the composition changes on the residual liquid during the vacuum distillation process have been calculated. A model combining a material balance and vapor-liquid equilibrium relations has been proposed under a constant vapor discharging flow rate and liquid composition changes have been calculated using the vapor pressures with respect to a dimensionless time. The behaviors have been compared with temperature and molten salt composition changes to simulate the process condition variation. The distillation of the residual salt has been dominated by LiCl which is the main component of the salt and CsCl of which vapor pressure is higher than that of LiCl would be readily removed. RbCl exhibits similar vapor pressure with LiCl and maintains its composition. However, $SrCl_2$ and $BaCl_2$ of which vapor pressures are much lower than that of LiCl are concentrated with time and expected to be possibly precipitated during the distillation when the initial compositions are increased.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.3
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• pp.199-206
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• 2013

Electrowinning process in pyroprocessing recovers U (uranium) and TRU (Trans Uranium) elements simultaneously from spent fuels using a liquid cadmium cathode (LCC). When the solubility limit of U deposits over 2.35wt% in Cd, U dendrites were formed on the LCC surface during the electrodeposition at $500^{\circ}C$. Due to the high surface area of dendritic U, the deposits were not submerged into the liquid cadmium pool but grow out of the LCC crucible. Since the U dendrites act as a solid cathode, it prevents the co-deposition of U and TRUs. In this study, the electrodeposition of U onto a LCC was carried out at 440 and $500^{\circ}C$ to compare the morphology and component of U deposits. The U deposits at $440^{\circ}C$ have a specific shape and were stacked regularly at the center of the LCC pool, while the U dendrites (i.e., ${\alpha}$-phase) at $500^{\circ}C$ were grow out of the LCC crucible. Through the microscopic observation and XRD analysis, the electrodeposits at $440^{\circ}C$, which have a round shape, were identified as an intermetallic compound such as $UCd_{11}$. It can be concluded that the LCC electrowinning operation at $440^{\circ}C$ achieves the co-recovery of U and TRU without the formation of U dendrites.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.165-172
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• 2018

As an approach for estimation of the droplet size in the molten salt-liquid metal extraction process, a droplet formation experiment at room temperature was conducted to evaluate the applicability of the Scheele-Meister model with water-mercury system as a surrogate that is similar to the molten salt-liquid metal system. In the experiment, droplets were formed through the nozzle and the droplet size was measured using a digital camera and image analysis software. As nozzles, commercially available needles with inner diameters (ID) of 0.018 cm and 0.025 cm and self-fabricated nozzles with 3-holes (ID: 0.0135 cm), 4-holes (ID: 0.0135 cm), and 2-holes (ID: 0.0148 cm) were used. The mercury penetration lengths in the nozzles were 1.3 cm for the needles and 0.5 cm for the self-fabricated nozzles. The droplets formed from each nozzle maintained stable spherical shape up to 20 cm below the nozzle. The droplet size measurements were within a 10% error range when compared to the Scheele-Meister model estimates. The experimental results show that the Scheele-Meister model for droplet size estimation can be applied to nozzles that stably form droplets in a water-mercury system.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.635-641
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• 2012

In Korea, slurry composted and biofiltered (SCB) liquid fertilizer is produced through the composting and biofiltering of animal waste. An appropriate guidelines involving proper treatment of SCB liquid fertilizer on turfgrass should be considered. An experiment was conducted to determine the optimum application amount, timing, and frequency of SCB liquid fertilizer for Zoysia japonica 'Millock'. The SCB liquid fertilizer was applied in low, medium, and high amount (N at 15, 25, and 40 $g{\cdot}m^{-2}$ per year in 2010, and 10, 20, and 40 $g{\cdot}m^{-2}$ per year in 2011, respectively) and treated during the growing season or dormancy period. During the growing season, SCB liquid fertilizer was applied twice or four times. The greatest improvement in turf quality for both years was in SCB plots applied four times with N at 40 $g{\cdot}m^{-2}$ per year during the growing season (SH4). This treatment exhibited turf color retention in the fall, and enhanced clipping yield during the growing and fall seasons. SCB plots with four times during the growing season (SL4, SM4, and SH4) exhibited higher shoot density relative to the same amount of other SCB treatments. Plots treated during the dormancy period also showed a high turf color index during the next growing season in 2011. The results indicate that SCB with high amount up to N at 40 $g{\cdot}m^{-2}$ per year applied four times during the growing season and dormant application produced high turf quality and growth, and could be recommended as an optimum application guide.

• Journal of Information Technology Services
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• v.22 no.4
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• pp.97-110
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• 2023

In this study, we propose a technique to automatically generate transfer documents using sensor data from livestock manure transfer systems. The research involves analyzing sensor data and applying machine learning techniques to derive optimized outcomes for livestock manure transfer documents. By comparing and contrasting with existing documents, we present a method for automatic document generation. Specifically, we propose the utilization of Gradient Boosting, a machine learning algorithm. The objective of this research is to enhance the efficiency of livestock manure and liquid byproduct management. Currently, stakeholders including producers, transporters, and processors manually input data into the livestock manure transfer management system during the disposal of manure and liquid byproducts. This manual process consumes additional labor, leads to data inconsistency, and complicates the management of distribution and treatment. Therefore, the aim of this study is to leverage data to automatically generate transfer documents, thereby increasing the efficiency of livestock manure and liquid byproduct management. By utilizing sensor data from livestock manure and liquid byproduct transport vehicles and employing machine learning algorithms, we establish a system that automates the validation of transfer documents, reducing the burden on producers, transporters, and processors. This efficient management system is anticipated to create a transparent environment for the distribution and treatment of livestock manure and liquid byproducts.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.70-74
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• 2011

Purpose: In the Nuclear Medicine department of Asan Medical Center, radioactive waste has been disposed of by using several disposal boxes designed for nuclear waste. However, some quantity of radioactivity has been detected occasionally due to some radiologists' carelessness not only from radioactive waste, but also from medical waste such as uncontrolled radioactive waste related to patients, poly gloves or saline solution bottles from radiopharmaceuticals laboratory. Thus, this study is going to suggest a solution to maintain the medical wastes made from controlled areas that can be below maximum permissible surface dose limits by finding the cause of radioactive contamination. Materials and methods: This study was taken place in 17 different places-2 medical wastebaskets in the waiting room, 2 medical wastebaskets in the PET room, 5 medical wastebaskets in the in vitro laboratory and 6 medical wastebaskets in the radiopharmaceuticals laboratory of the East building, 2 medical wastebaskets in the waiting room of the New building of Nuclear Medicine Department in Asan Medical Center from April to August 2010. Mean radioactivity and its standard deviation of each place have been found by measuring surface contamination of medical wastebaskets and backgrounds twice a week, totaling 30 times. An independent t-test of SPSS (Ver. 12.0) statistic program has been used for statistical analysis. Swabs, saline solution bottles and poly gloves collected from each place also measured 30 times, respectively. Results: This study analyzed medical waste and the backgrounds of each place by using survey meter detectors that significant differences of five places did not exist, but existed statistically in twelve places (p<0.05). Also, swabs, saline solution bottles and poly gloves collected from each radioactive waste partly exceed the legal dose limit as a result of measuring by a gamma counter. Conclusion: Backgrounds and the surface doses of radioactive disposal box in all 17 places measured by the survey meter did not exceed the legal dose limit; however, it obviously showed that there were prominent differences in 12 places. Assuming that the cause of the differences was swabs, saline solution bottles and gloves, we examined them by gamma counter, and the results showed remarkably high doses of radioactivity. Consequently, swabs and poly gloves which are normally disposed in the general medical waste box should be disposed in the radioactive waste box furnished by radiopharmaceuticals laboratory. Also, saline solution discharged from radioactive pharmaceutical places is considered as radioactive liquid waste so that it should be disposed of by the septic tank specifically designed for radioactive liquid.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.183-193
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• 2018

Currently, the Korea Atomic Energy Research Institute (KAERI) is planning to build the Ki-Jang Research Reactor (KJRR) in Ki-Jang, Busan. It is important to safely dispose of low-level radioactive waste from the operation of the reactor. The most efficient way to treat radioactive waste is cement solidification. For a radioactive waste disposal facility, cement solidification is performed based on specific waste acceptance criteria such as compressive strength, free-standing water, immersion and leaching tests. Above all, the leaching test is important to final disposal. The leakage of radioactive waste such as $^{137}Cs$ causes not only regional problems but also serious global ones. The cement solidification method is simple, and cheaper than other solidification methods, but has a lower leaching resistance. Thus, this study was focused on the development of cement solidification for an enhancement of cesium leaching resistance. We used Zeolite and Loess to improve the cesium leaching resistance of KJRR cement solidification containing simulated KJRR liquid waste. Based on an SEM-EDS spectrum analysis, we confirmed that Zeolite and Loess successfully isolated KJRR cement solidification. A leaching test was carried out according to the ANS 16.1 test method. The ANS 16.1 test is performed to analyze cesium ion concentration in leachate of KJRR cement for 90 days. Thus, a leaching test was carried out using simulated KJRR liquid waste containing $3000mg{\cdot}L^{-1}$ of cesium for 90 days. KJRR cement solidification with Zeolite and Loess led to cesium leaching resistance values that were 27.90% and 21.08% higher than the control values. In addition, in several tests such as free-standing water, compressive strength, immersion, and leaching tests, all KJRR cement solidification met the waste acceptance or satisfied the waste acceptance criteria for final disposal.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.4
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• pp.77-85
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• 2010

Pig slurry has been considered as environmental waste to be treated in an appropriate manner. Recently, there has been the movement toward reusing the pig slurry as an alternative fertilizer sources for agricultural lands. For instance, SCB(Slurry Composting & Biofiltration) liquid fertilizer has been developed and widely used in Korea. However, the impacts of swine slurry liquid fertilizers on both agricultural environment and crop yield have not been investigated yet. Therefore, the current study was conducted to accumulate the basic data which can be subsequently used to determine appropriate application amount of swine slurry liquid fertilizers (SCB liquid fertilizer and storage liquid fertilizer) as well as the application method for each liquid fertilizer. For this, growth of rice was cultivated under the treatment of SCB liquid fertilizer, storage liquid fertilizer, and chemical fertilizer. Also, control treatment (no fertilizer) was included for comparison and all treatments were conducted in five replication. Rice growth was good with the treatment in the order of chemical fertilizer>storage liquid fertilizer>SCB liquid fertilizer>control and likewise, the yield amount of rice straw was in the same order of rice growth. The rice yield amount appeared to be no difference among the treatment except control which showed the least yield amount. Also there was no difference in nitrogen and phosphorus concentrations in rice among the treatment except control which showed the least concentration.

• Journal of Magnetics
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• v.15 no.2
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• pp.91-98
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• 2010

The paper presents results of a study on the selective separation technology of ferrous and non-ferrous metals from broken light bulbs. The proposed method is to use magnetic fluids to obtain a magnetic fluid based- separation. [1] The study was conducted using three types of waste materials: regular light bulbs, auto light bulbs and neon tubes. In order to process the waste materials, a six stages technologic flow was developed: a) separation of light bulbs components; b) Physical and chemical analysis of raw materials; c) grain conditioning of the raw material; d) dry magnetic separation of ferrous components; e) magnetic fluid separation of non-magnetic material; f) recovery of the magnetic fluid adhered to the surface of the separated material grains. [2] This study shows that magnetic fluid separation is only profitable for regular and auto light bulbs and is not profitable in the case of neon tubes.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.433-433
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• 2004

Neutron induced prompt gamma-ray spectroscopy (NIPS) system measures the prompt gamma-ray, emitting by the interaction of a neutron with various materials. This system will be of great benefit to scientists worldwide, since it provides the non-destructive measurement of many elements in either solid or liquid wastes. A NIPS facility has been developed in Nuclear Chemistry Research Division, at Korea Atomic Energy Research Institute (KAERI) with the aim of analyzing the major component elements in both aqueous and solid samples.(omitted)