Trends of 3H Decontamination Technology and Design of Pilot Hybrid Technology Facilities for 3H Contaminated Water Treatment

Jiyang So,Doocheol Kim,Seonggeon Kim,Sangwook Lee,Seongjoo Kang,Minho Kwak,Seungil Kim 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

In the field of 3H decontamination technology, the number of patent applications worldwide has been steadily increasing since 2012 after the Fukushima nuclear accident. In particular, Japan has a relatively large number of intellectual property rights in the field of 3H processing technology, and it seems to have entered a mature stage in which the growth rate of patent applications is slightly reduced. In Japan, tritium is being decontaminated through the Semi-Pilot-class complex process (ROSATOM, Russia) using vacuum distillation and hydrogen isotope exchange reaction, and the Combined Electrolysis Catalytic Exchange (CECE, Kurion, U.S.) process. However, it is not enough to handle the increasing number of HTOs every year, so the decision to release them to the sea has been made. Another commercial technology in foreign countries is the vapor phase catalyst exchange process (VPCE) in operation at the Darlington Nuclear Power Plant in Canada. This process is a case of applying tritium exchange technology using a catalyst in a high-temperature vapor state. The only commercially available tritium removal technology in Korea is the Wolseong Nuclear Power Plant’s Removal Facility (TRF). However, TRF is a process for removing HTO from D2O of pure water, so it is suitable only for heavy water with high tritium concentration, and is not suitable for seawater caused by Fukushima nuclear power plant’s serious accident, and surface water and groundwater contaminated by environmental outflow of tritium. Until now, such as low-temperature decompression distillation method, water-hydrogen isotope exchange method, gas hydrate method, acid and alkali treatment method, adsorption method using inorganic adsorbent (zeolite, activated carbon), separator method using electrolysis, ion exchange adsorption method using ion exchange resin, etc. have been studied as leading technologies for tritium decontamination. However, any single technology alone has problems such as energy efficiency and processing capacity in processing tritium, and needs to be supplemented. Therefore, in this study, four core technologies with potential for development were selected to select the elemental technology field of pilot facilities for treating tritium, and specialized research teams from four universities are conducting technology development. It was verified that, although each process has different operating conditions, tritium removal performance is up to 60% in the multi-stage zeolite membrane process, 30% in the metal oxide & electrochemical treatment process, 43% in the process using hydrophilic inorganic adsorbent, and 8% in the process using functional ion exchange resin. After that, in order to fuse with the pretreatment process technology for treating various water quality tritium contaminated water conducted in previous studies, the hybrid composite process was designed by reflecting the characteristics of each technology. The first goal is to create a Pilot hybrid tritium removal facility with 70% tritium removal efficiency and a flow rate of 10 L/hr, and eventually develop a 100 L/hr flow tritium removal system with 80% tritium removal efficiency through performance improvement and scale-up. It is also considering technology for the postprocessing process in the future.

Evaluation of Separation/Concentration Treatment System to 10 m3 Scale Boron-Containing Nuclear Power Plant Discharge Water

Seongjoo Kang,Sangwook Lee,Doocheol Kim,Jiyang So,Seonggeon Kim,Seung-il Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

Domestic nuclear power plants can affect the environment if multiple devices are operated on one site and even a trace amount of pollutants that may affect the environment after power generation are simultaneously discharged. Therefore, not only radioactive substances but also ionic substances such as boron should be discharged as minimally as possible. We adopted pilot CDI and SD-ELIX sytem to separating and concenrating of boron containing nulcear power plant discharge water. The boron concentration of the initial inflow water tended to decrease over time. The water quality of concentrated water also reached its peak until the initial 60 minutes, but tended to decrease in line with the decrease in the inflow water concentration. The boron removal rate was in the range of 85 to 99% with respect to the initial boron concentration of 15 to 25 mg/L. On the other hand, performance degradation due to the use of electrochemical modules is also observed, and regeneration through low ion-containing water cleaning effective. We shortened processing time by considering the optimal flow rate conditions and conductivity conditions and converting electrochemical modules into series or parallel.

A Study on the Development of Methyl Iodine Adsorption Materials Using Waste Concrete and Waste Soil

Sangwook Lee,Seongjoo Kang,Doocheol Kim,Jiyang So,Seonggeon Kim,Minho Kwak,Seungil Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

Radioactive waste generated during decommissioning of nuclear power plants is classified according to the degree of radioactivity, of which concrete and soil are reclassified, some are discharged, and the rest is recycled. However, the management cost of large amounts of concrete and soil accounts for about 40% of the total waste management cost. In this study, a material that absorbs methyl iodine, a radioactive gas generated from nuclear power plants, was developed by materializing these concrete and soil, and performance evaluation was conducted. A ceramic filter was manufactured by forming and sintering mixed materials using waste concrete, waste soil, and by-products generated in steel mills, and TEDA was attached to the ceramic filter by 5wt% to 20wt% before adsorption performance test. During the deposition process, TEDA was vaporized at 95°C and attached to a ceramic filter, and the amount of TEDA deposition was analyzed using ICP-MS. The adsorption performance test device set experimental conditions based on ASTM-D3808. High purity nitrogen gas, nitrogen gas and methyl iodine mixed gas were used, the supply amount of methyl iodine was 1.75 ppm, the flow rate of gas was 12 m/min, and the supply of water was determined using the vapor pressure value of 30°C and the ideal gas equation to maintain 95%. Gas from the gas collector was sampled to analyze the removal efficiency of methyl iodine, and the amount of methyl iodine detected was measured using a methyl iodine detection tube.

Kinect를 이용한 체감형 시스템의 구현 및 전시 사례

최요셉(YoSeph Choi),김두혁(DooHyeok Kim),유영훈(YoungHoon Yoo),김정훈(ungHoon Kim),김기현(KiHyun Kim),강두철(DooCheol Kang),박현우(HyunWoo Park),윤태수(TeaSoo Yun) 한국HCI학회 2013 한국HCI학회 학술대회 Vol.2013 No.1

Development of Inorganic Adsorbent for Tritium Contaminated Water Treatment

Jiyang So,Seungkyu Hwang,Yunsuk Huh,Doocheol Kim,Seonggeon Kim,Sangwook Lee,Seongjoo Kang,Minho Kwak,Seungil Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

In this study, four technologies were selected to treat river water, lake water, and groundwater that may be contaminated by tritium contaminated water and tritium outflow from nuclear power plants, performance evaluation was performed with a lab-scale device, and then a pilot-scale hybrid removal facility was designed. In the case of hybrid removal facilities, it consists of a pretreatment unit, a main treatment unit, and a post-treatment unit. After removing some ionic, particulate pollutants and tritium from the pretreatment unit consisting of UF, RO, EDI, and CDI, pure water (2 μS/cm) tritium contaminated water is sent to the main treatment process. In this treatment process, which is operated by combining four single process technologies using an inorganic adsorbent, a zeolite membrane, an electrochemical module and aluminumsupported ion exchange resin, the concentration of tritium can be reduced. At this time, the tritium treatment efficiency of this treatment process can be increased by improving the operation order of four single processes and the performance of inorganic adsorbents, zeolite membrane, electrochemical modules, and aluminum- supported ion exchange resins used in a single process. Therefore, in this study, as part of a study to increase the processing efficiency of the main treatment facility, the tritium removal efficiency according to the type of inorganic adsorbent was compared, and considerations were considered when operating the complex process.

Dual-wavelength Digital Holography Microscope for BGA Measurement Using Partial Coherence Sources

Hyungjun Cho,Doocheol Kim,유영훈,정원기,Sanghoon Shin 한국광학회 2011 Current Optics and Photonics Vol.15 No.4

Dual-wavelength holography has a better axial range than single-wavelength holography, allowing unambiguous phase imaging. Partial coherence sources reduce coherent noise, resulting in improved reconstructed images. We measured a ball-grid array using dual-wavelength holography with partial coherence sources. This holography method is useful for measurement samples that exhibit coherence noise and have a step height larger than the single wavelength used in holography.

Deflectometric Measurement of a Fine Metal Mask by Using Near Infrared to Reduce Scattering

Silin Na,Sanghoon SHIN,Doocheol KIM,Younghun Yu 한국물리학회 2016 New Physics: Sae Mulli Vol.66 No.1

Deflectometry is a non-interferometric method that is easy to set up and can be easily applied to investigations of the flatness of plates. The samples need to have specular surfaces. However, every surface has roughness and is not perfectly specular. The specular reflection depends on the wavelength and the size of the scatterer on the surface. We investigated the scattering effect at different wavelengths and chose an appropriate wavelength of the light source for reducing the scattering effect. Fine metal masks (FMMs) are used in organic deposition processes and are required to be flat, even though most FMMs have partially specular surfaces. Experimentally, we used near infrared deflectometry to investigate the variations in the shapes of the surfaces of FMMs subjected to different stresses.

형광 공초점 현미경의 side-lobe 감소에 대한 연구

조형준,최치규,김두철,유영훈 濟州大學校 基礎科學硏究所 2002 基礎科學硏究 Vol.15 No.2

구면렌즈를 사용한 광학 관측계의 경우 관측계 자체의 문제뿐만 아니라 시료의 두께 및 굴절률에 따라 위상오차에 의한 side-lobe가 발생한다. 특히 형광 공초점 현미경의 경우 시료 제작시 사용되는 형광물질, 증류수, 식염수 등의 불규칙적인 사용으로 위상오차에 의한 side-lobe의 발생이 매우 심각하다. 본 연구에서는 시료의 특성에 따른 side-lobe를 최소화하기 위하여 Herschel 조건을 도입하였다. 또한 형광 공초점 현미경을 구성하여 Herschel 조건에 의한 위상 보정을 함으로써 side-lobe가 최소화됨을 확인하였다. The effects of side-lobe on the axial response in fluorescence type confocal microscope have been investigated by computer simulation and experiment. The axial response becomes broad and asymmetric with side-lobes, and the peak intensity of the image was greatly reduced because the Herschel condition was violated. We found the condition for the minimized of side-lobe with the Herschel condition according to change of optical path altering the distance from sample to objective lens and from objective lens to image. From the results of computer simulation and experiment, we found that the distribution of intensity was shifted, the peak of intensity being increased and the axial response was symmetric after compensating a phase error according to thickness was increased. From analysis of this results, an optimized axial response can be achieved by minimizing side-lobe and side-lobe can be minimized by compensating phase error.

Twin-Image Elimination in an In-Line Digital Holographic Microscope

Hyungjun Cho,Younghun Yu,Doocheol Kim,Jung-Young Son,Sanghoon Shin,Wongun Jang 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.4

A novel method is employed to eliminate the twin images in the so-called ``in-line" digital holographic microscope. We could develop a digital holographic microscope that can solve the problems of overlapping of real and imaginary images and eliminate one of them by padding and removing the DC term by using an averaging method. The entire process requires only one digital hologram. A novel method is employed to eliminate the twin images in the so-called ``in-line" digital holographic microscope. We could develop a digital holographic microscope that can solve the problems of overlapping of real and imaginary images and eliminate one of them by padding and removing the DC term by using an averaging method. The entire process requires only one digital hologram.

액체와 Digital Holographic Microscopy을 이용한 비구면 렌즈 측정 연구

김두철,신상훈,유영훈,Kim, Doocheol,Shin, Sanghoon,Yu, Younghun 한국광학회 2013 한국광학회지 Vol.24 No.6

디지털 홀로그래피 현미경은 기준광과 시료의 굴절률과 두께에 의한 광경로 차이를 간섭 방법을 이용하여 측정하여 3차원 형상을 측정하는 방법이다. 그리고 광 경로차는 시료의 두께와 시료와 시료 주변의 굴절률 차이에 의존한다. 시료 형상 기울기가 매우 큰 경우에는 광 경로차가 커져 일반적인 간섭 방법으로는 측정이 어렵다. 이런 경우 시료를 액체에 담그어 측정하면 광 경로차가 매우 작아져서 일반적인 간섭 방법을 이용하여 측정할 수 있다. 본 연구에서는 디지털 홀로그램 현미경과 액체를 이용하여 기울기가 큰 비구면 렌즈의 형상을 측정하는 연구를 하였다. 시료의 굴절률과 비슷한 액체를 선택함으로서 비구면 렌즈의 정밀한 3차원 측정이 가능하였다. Digital holographic microscopy allows optical path difference measurement. Optical path difference depends on both the refractive index and the morphology of the sample. When interference fringes are very closely spaced, the phase data contain high frequencies where $2{\pi}$ ambiguities cannot be resolved. The immersion testing method, which is a transmission test while the sample is immersed in liquid, is very effective in reducing high frequency fringes in transmission measurements so that large dynamic range testing is possible for a non-null configuration. We developed a digital holographic microscope using liquid that can measure the high numerical aperture aspheric morphology of a sample. This system provides highly precise three-dimensional information on the sample. By improving the experimental method, choosing liquids which have similar refractive index to the sample, we can measure more accurate three-dimensional information on the samples.