• Membrane and Water Treatment
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• v.3 no.4
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• pp.231-242
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• 2012

The performance of a nanofiltration membrane for treatment of a low-level radioactive liquid waste was investigated through static and dynamic tests. The liquid waste ("carbonated water") was obtained during conversion of $UF_6$ to $UO_2$. In the static tests membrane samples were immersed in the waste for 24, 48 or 72 h. The transport properties of the samples (hydraulic permeability, permeate flow, selectivity) were evaluated before and after immersion in the waste. In the dynamic tests the waste was permeated in a permeation flow front system under 0.5 MPa, to determine the selectivity of NF membranes to uranium. The surface layer of the membrane was characterized by zeta potential, field emission microscopy, atomic force spectroscopy and infrared spectroscopy. The static test showed that the pore size distribution of the selective layer was altered, but the membrane surface charge was not significantly changed. 99% of uranium was rejected after the dynamic tests.

• Journal of Radiation Industry
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• v.18 no.2
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• pp.147-153
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• 2024

Radioactive liquid waste generated during operation and overhaul is collected and reused through the radioactive liquid waste treatment system and continuous monitoring system in the nuclear power plant or discharged to the outside if it satisfies the limit within the control and monitoring. However, there are concerns about boric acid management, which controls the power output of nuclear power plants in radioactive liquid waste. Due to the behavior of boric acid, it is difficult to remove it in the existing liquid radwaste system, and the concentration of boric acid water discharged tends to be higher than the natural state of 5 ppm, so additional facilities should be considered. Therefore, this study aims to evaluate the radiological effects of radioactive waste treatment facilities that are under development and use them as a basis for managing worker exposure and evaluating the safety of facilities in the future.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4441-4448
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• 2022

The electrochemical oxidation process has been widely studied in the field of wastewater treatment for the decomposition of organic materials through oxidation using ·OH generated on the anode. Pt anode electrodes with high durability and long-term operability have a low oxygen evolution potential, making them unsuitable for electrochemical oxidation processes. Therefore, to apply Pt electrodes that are suitable for long-term operation and large-scale processes, it is necessary to develop a new method for improving the decomposition rate of organic materials. This study introduces a method to improve the decomposition rate of organic materials when using a Pt anode electrode in the electrochemical oxidation process for the treatment of organic decontamination liquid waste. Electrochemical decomposition tests were performed using sodium dodecylbenzenesulfonate (SDBS) as a representative organic material and a Pt mesh as the anode electrode. Y₂O₃ particles were introduced into the electrolytic cell to improve the decomposition rate. The decomposition rate significantly improved from 21% to 99%, and the current efficiency also improved. These results can be applied to the electrochemical oxidation process without additional system modification to enhance the decomposition rate and current efficiency.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.3
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• pp.219-230
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• 2004

Most of the low-level liquid radioactive wastes generated from PWR plants are classified into high or low total suspended solid(HTDS or LTDS), and into radiochemical and radioactive laundry waste. Although the evaporation process has a high decontami- nation ability, it has several problems such as corrosion, foam, and congestion. A new liquid waste disposal process using the ion-exchange demineralizer(IED), instead of the current evaporation process, has been introduced into the Yonggwang NPP #5 and 6. These two methods have been compared to understand the differences in this study. Aspects compared here were the released radioactivity amount of the liquid radioactive wastes, the dose of off-site residents, the decontamination factor, and the amount of the solid radioactive wastes. The IED system is designed to discharge higher radioactivity about 20% than the evaporating system, and the actual radioactivity released from the evaporating and IED system were 0.473mCi and 1.098mCi, respectively. The radioactivity released from the IED was 2.32 times higher than that of the evaporating system. The dose of off-site residents was $2.97{\times}10^{-6}$mSv for the evaporating system, and $6.47{\times}10^{-6}$mSv for IED. The decontamination factor(DF) of the evaporator is, in most cases, far lower than the lower limits of detection(LLD) with the Ge-Li detector. Due to the low concentration of the liquid wastes collected from the liquid waste system, the decontamination factor of IED is very low. Since there is not enough data on the amount of solid radioactive wastes generated by the evaporation system, the comparison on these two systems has been conducted on the basis of the design, and the comparison result was that the evaporating system generated more wastes about 40% than IED.

• Journal of Animal Environmental Science
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• v.4 no.1
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• pp.63-71
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• 1998

The dramatic increase in both swine and cattle production in Korea has presented problems related to protection of water resources. Animal wastes are a potentially valuable source of plant nutrients. Modern liquid waste management plans for a livestock housing need to focus on the slurry aeration and composting control methods and cost effective equipments. Recent developments in the animal manure liquid composting make it possible to improve the manure more easier to handle, reduce the odorous, labors and bedding materials, kill the weed seeds etc. However, there are some disadvantages, the aerator consumes much electrical power and initial cost is high. To solve these problems, this study is intended to develop a key points such as slurry aeration and dilution, liquid waste composting equipments.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.369-376
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• 2010

The purpose of this study is to reprocess Waste-LCD(Liquid Crystal Display), to widely increase specific surface-area by foaming agent in the process of reprocessing and to use as a substrate of water treatment which is increased the ability of biological treatment, as well as to control non-point source pollutants produced by surface run off during rainfall with using this substrate, and to improve water quality of public watershed as developing substrate for water treatment to be able to purify second treated water which is exhausted at the wastewater treatment plant. The average removal efficiency of Waste-LCD that using the foaming technology was SS 71.2%, BOD 55.7%, COD 58.4%, T-N 29.5% and T-P was 50.3%. Almost Media, early stage showed low removal efficiency of SS and BOD. However, it became high when the microorganism adhered the Media. The variation of SS removal efficiency was high by inflow concentration of SS. The reason for the Media 4 showed high SS removal efficiency is that it has wide specific surface-area, and also it has a pore. All in all, it shows floating matter treatment ability not only inside but it also works outside of the substrate.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.1
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• pp.9-27
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• 2021

As an example of research activities in decontamination for decommissioning, new data are presented on the options for corrosion layer dissolution during the decommissioning decontamination, or persulfate regeneration for decontamination solutions re-use. For the management of spent decontamination solutions, new method based on solvent extraction of radionuclides into ionic liquid followed by electrodeposition of the radionuclides has been developed. Fields of applications of composite inorganic-organic absorbers or solid extractants with polyacrylonitrile (PAN) binding matrix for the treatment of liquid radioactive waste are reviewed; a method for americium separation from the boric acid containing NPP evaporator concentrates based on the TODGA-PAN material is discussed in more detail. Performance of a model of radionuclide transport, developed and implemented within the GoldSim programming environment, for the safety studies of the LLW/ILW repository is demonstrated on the specific case of the Richard repository (Czech Republic). Continuation and even broadening of these activities are expected in connection with the approaching end of the lifespan of the first blocks of the Czech NPPs.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.141-148
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• 2003

A data collection of a liquid radioactive waste treatment process of a research organization became necessary while developing the RAWMIS(Radioactive Waste Management Integration System) which it can generate personal history management for efficient management of a waste, documents, all kinds of statistics. This paper introduces an input and output application program design to do to database with data in the results and a stream process of a treatment that analyzed the waste occurrence present situation and data by treatment process. Data on the actual treatment process that is not limited experiment improve by a document, human traces, saving of material resources and improve with efficiency of tracking about a radioactive waste and a process and give help to radioactive waste material valance and inventory study.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.05a
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• pp.271-272
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• 2017

• Economic and Environmental Geology
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• v.51 no.2
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• pp.177-183
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• 2018

This study assessed an application of electrocoagulation (EC) for the removal of cobalt (Co) in radioactive liquid waste from nuclear power plant. The EC process is an electrochemical means to remove a contaminant in wastewater and a novel process to complement the disadvantage of chemical treatment and membrane process. Radioactive liquid waste has been produced from washing process of radio nuclide power plant cooling system. The EC process eliminates Co from the electrolyte within 10 min; in addition, the dewatered sludge produced in EC process is only 0.2 g. Therefore, the EC process is a promising technique for the removal of Co in radioactive liquid waste and volume reduction of wastes.