Behavior Diagram Analysis to Define Requirements on Site Clearance and Remediation

Yunjeong Hong,Heeseoung Park,Jeongguk Kim 한국방사성폐기물학회 2018 한국방사성폐기물학회 학술논문요약집 Vol.2018 No.10

Verification Plan for Compliance With Permissible Standards for Clearance of Specified Waste

Yunjeong Hong,Won Hyuk Jang,Hongrae Jeon 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

The types of waste generated in radiation controlled areas of nuclear facilities are very diverse. Among them, the waste containing hazardous materials such as electrical equipment and fire safety equipment that do not directly handle radioactive materials is also primarily classified as radioactive waste because it was used and stored in the radiation controlled area. Such wastes include periodic consumables such as fluorescent lamps, fire extinguishers, batteries, and gas containers after use. The waste is ambiguous and cannot be easily treated as radioactive waste or waste subject to clearance, and has been stored in a radiation controlled area for a long time, and the amount is continuously increasing. The storage space is saturated and has difficulty in management. IAEA ISO-7503-2016 clearly states that surface contamination measurement can be applied to surface contamination substrates (impermeable, non-activated) instead of volume contamination measurement. In order to solve these concerns, some facilities within the Korea Atomic Energy Research Institute were selected to explore self-disposal methods based on surface contamination in consideration of the characteristics of waste and facility contamination. The surface contamination degree and qualitative gamma spectroscopic analysis were carried out by the method. First, we examined the characteristics of the facility, the history of the air pollution level of the usage/storage space, and periodic inspection records. Second, we measured the physical properties (area/weight) of the waste in the same treatment way as the existing waste. Third, gamma dose rate and surface contamination (direct/indirect method) are measured for the entire area to confirm contamination is possible. It was confirmed that the concentration standard was satisfied. In order to clarify the presence of contamination, a qualitative method of gamma nuclide analysis was also performed. All surveys/measurements of 4 types of waste at 7 facilities were performed and it was confirmed that all waste satisfies the permissible concentration standard for clearance which conservatively set at 0.1 Bq/g as the permissible concentration standard. In the future, We hope that you will use this as a reference to search for easier disposal methods for regulatory bodies and specified waste disposal methods, and contribute to reducing the amount of radioactive waste generated.

A Case Study for Clearance of Volumetric Contaminated Wood Wastes

Yunjeong Hong,WonHyuk Jang 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

As the management procedure for self-disposal wastes stored in the radiation controlled area within the Korea Atomic Energy Research Institute (KAERI) have been established, and the types and quantities of wastes are increasing. In order to carry out the disposal of wastes with various generation histories, we expanded the processing range from surface contaminated waste, which was already in progress, to volumetric contaminated waste. In this paper, a case study of self-disposal of volumetric contaminated radioactive waste for which final disposal has been completed is described. In order to carry out of self-disposal of volumetric contaminated waste, it is important to collect representative samples and prove their representativenss. Based on this, a treatment plan was established after reviewing the history of the waste to be disposed of, and the treatment work was carried out as follows; waste collection, classification by size and shape, radiation (activity) measurement, sampling of representative samples, radioactivity concentration analysis, notification to regulatory bodies and question-and-answer, final disposal. The waste is judged have no potential for contamination because the polywood used to set the flat floor between the steel frame and floorboards in the experimental greenhouse didn’t come into contact with radioactive material. However, due to the conservative approach to the presence or absence of contamination, the treatment plan was established assuming volumetric contaminated waste. The type of waste is single wood, and the major contaminating radionuclides are Sr-85 and Cs-137. After the waste was collected and sorted by size and shape, it was weighed and a representative sampling amount and sampling method were set up. A direct method of surface contamination was performed on the entire area, and the representative sample was divided into three groups of homogenized population samples using the trisection method, with three points (upper/middle/below) were sampled at a 200:1 ratio, and radioactivity concentration analysis was conducted. After confirming that the concentration was below the allowable concentration for selfdisposal, the final disposal was completed after receiving approval after reporting to the regulatory body. As a result of radioactivity concentration analysis of representative samples, the maximum radioactivity concentration for each nuclide was Sr-85: < MDC (0.00178), Cs-137 : 0.00183 Bq/g (Sr-85 : 1 Bq/g, Cs-137 : 0.1 Bq/g), which meets the nuclide allowable concentration standard. It was confirmed that the total maximum fraction of 0.02 Bq/g satisfies the criteria (In the case of mixed nuclides, the sum of the fraction is less than 1). This paper introduces the establishment and implementation of self-disposal procedures based on the experience of self-disposal of radioactive waste with volumetric contaminants, and is going to utilize it as a basic material for self-disposal of radioactive waste with volumetric contaminants that will continue in the future and contribute to the reduction of radioactive wastes.

Requirement of Conceptual Design for Decommissioning Information Integration Management System

Yunjeong Hong,Seungkook Park,Heeseong Park 한국방사성폐기물학회 2017 한국방사성폐기물학회 학술논문요약집 Vol.2017 No.05

A Study of Traceability and Change Management Based on Decommissioning Information for a Nuclear Facility

Yunjeong Hong,Heeseoung Park,Jongjin Kim,Jeong-guk Kim 한국방사성폐기물학회 2018 한국방사성폐기물학회 학술논문요약집 Vol.2018 No.05

Establishment of Management System for Radioactive Waste Containings Hazardous Substances

Yunjeong Hong,Dongju Lee,Daeseong Nam,Jonghwa Pack,Yungun Jung,Heungju Cho,Sungjin Han,Wonhyuk Jang,Tackjin Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

As the acceptance criteria for low-intermediate-level radioactive waste cave disposal facilities of Korea Radioactive Waste Agency (KORAD) were revised, the requirements for characterization of whether radioactive waste contains hazardous substances have been strengthened. In addition, As the recent the Nuclear Safety and Security Commission Notice (Regulations on Delivery of Low- Medium-Level Radioactive Waste) scheduled to be revised, the management targets and standards for hazardous substances are scheduled to be specified and detailed. Accordingly, the Korea Atomic Energy Research Institute (KAERI) needs to prepare management methods and procedures for hazardous substances. In particular, in order to characterize the chemical requirements (explosiveness, ignitability, flammability, corrosiveness, and toxicity) contained in radioactive waste, it must be proven through documents or data that each item does not contain hazardous substances, and quality assurance for the overall process must be provided. In order to identify the characteristics of radioactive waste that will continue to be generated in the future, KAERI needs to introduce a management system for hazardous substances in radioactive waste and establish a quality assurance system. Currently, KAERI is thoroughly managing chelates (EDTA, NTA, etc.), but the detailed management procedures for hazardous substances related to chemical requirements in radioactive waste in the radiation management area specified above are insufficient. The KAERI’s Laboratory Safety Information Network has a total periodic regulatory review system in place for the purchase, movement, and disposal of chemical substances for each facility. However, there is no documents or data to prove that the hazardous substances held in the facility are not included in the radioactive waste, and there are no procedures for managing hazardous substances. Therefore, it is necessary to establish procedures for the management of hazardous substances, and we plan to prepare management procedures for hazardous substances so that chemical substances can be managed according to the procedures at each facility during preliminary inspection before receiving radioactive waste. The procedure provides definitions of terms and types of management targets for each characteristic of the chemical requirements specified above (explosiveness, ignition, flammability, corrosiveness, and toxicity). In addition, procedure also contains treatment methods of radioactive waste generated by using hazardous substances and management methods of in/out, quantity, history of that substances, etc. As the law is revised in the future, management will be carried out according to the relevant procedures. In this study, we aim to present the hazardous substance management procedures being established to determine whether radioactive waste contains hazardous substances in accordance with the revised the notice and strengthened acceptance criteria. Through this, we hope to contribute to improving reliability so that radioactive waste could be disposed of thoroughly and safely.

Large magnetic anisotropy in canted antiferromagneticSr2IrO4single crystals

Hong, Yunjeong,Jo, Younjung,Choi, Hwan Young,Lee, Nara,Choi, Young Jai,Kang, Woun American Physical Society 2016 Physical Review B Vol.93 No.9

<P>The magnetocrystalline contribution to magnetic anisotropy was studied in the canted antiferromagnetic state of layered Sr2IrO4 single crystals. We performed torque measurements in magnetic fields up to 9 T under various magnetic field orientations. The strong dependence of torque on the magnetic field revealed that the magnetic easy axis is along the in-plane direction and that the observed field-induced weak ferromagnetic order is attributed only to the in-plane component of the external magnetic field. The dependence of torque on the angle produces a twofold symmetric sawtoothlike shape. A simple model consisting of canted antiferromagnetic and magnetic induction terms showed good agreement with themeasured torque. These results showthat magnetic anisotropy is closely related to the anisotropy of the exchange between antiferromagnetic moments whose canting is mediated by the Dzyaloshinsky-Moriya interaction. Our study demonstrates that torque magnetometry can be extended to the investigation of the magnetic anisotropy of complex magnetic phases.</P>

가스 누출 탐지 모델 개발을 위한 딥러닝 기반 초음파 이미지 학습 연구

구윤정(Yunjeong Gu),박광현(Kwanghyun Park),이원희(Wonhee Lee),송병훈(Byunghun Song),홍정표(Jungpyo Hong),신준호(Junho Shin) 한국방재학회 2023 한국방재학회논문집 Vol.23 No.6

가스는 눈에 보이지 않아 가스 누출 사고가 발생하는 경우 누출 위치 확인 및 사고 규모 예측이 어렵다. 본 연구에서는 가스 누출 시 발생하는 초음파를 시각화하는 기술을 이용하여 가스 누출 여부 뿐만 아니라 가스 누출 위치, 누출 유량 정보를 획득할 수 있는 딥러닝 기반의 가스 누출 탐지 모델을 개발하였다. 연구 방법은 크게 데이터 수집 및 모델 학습으로 구분된다. 먼저 데이터 수집은 초음파 카메라를 이용하여 측정 거리( 1, 3 m ) 및 가스 누출 유량(0~8 L/min)에 따른 초음파 이미지를 수집하였다. 이미지 학습은 YOLO를 이용하였으며 가스 누출 유량 범위에 따라 Class를 설정한 후 모델을 학습하였다. 수집한 초음파 이미지는 측정 거리가 멀어질수록 선명도가 낮아지고, 누출 유량에 따른 이미지의 차이가 거의 없어 육안으로 구분하기 어려웠다. 그러나 모델 학습 결과 precision 0.960, recall 0.967, mAP (IoU 50%) 0.987로 높은 성능을 나타내었으므로 향후 산업현장의 가스 안전 관리 기술로 적용하는 경우 가스 누출로 발생하는 사고를 탐지하고 누출 위치, 누출 유량 등의 정보 전달을 통해 적절한 사고 대응을 제시할 수 있을 것으로 기대된다. If a gas leak occurs in an industrial area, identifying the location of the gas leak and predicting the scale of the accident are challenging owing to the invisible nature of the gas. In this study, we developed a deep learning-based gas leak detection model that can obtain not only the gas leak status, but also the gas leak location and flow rate information, by using technology to visualize the ultrasonic waves generated during gas leaks. Research methods are broadly categorized into data collection and model learning methods. First, data was collected using an ultrasonic camera to capture ultrasonic images at different measurement distances (1 and 3 m) and gas leak flow rates (0-8 L/min). YOLO (You Only Look Once) was used for image learning, and the model was trained after setting the class according to the gas-leak flow range. The clarity of the collected ultrasonic images decreased as the measurement distance increased. In addition, there was little difference between the images for each leakage flow rate, posing challenges in distinguishing them with the naked eye. However, the model learning results showed high accuracy, with a precision of 0.960, recall of 0.967, and mAP (IoU (Intersection over Union) 50%) of 0.987. Applying this model as a gas safety management technology at industrial sites, enables the accurate determination of gas leak status, gas leak location, and gas leakage flow. This information is expected to guide appropriate accident responses for workers.

Characterization of Erythropoietin Producing Cell Lines after Introduction of Urea Cycle Enzymes, Carbamoly Phosphate Synthetase and Ornithine Transcarbamoylase

Kim Hong-Jin,Lee YunJeong,Kim NaYoung,Kim HyungJin,Choi JungHo,Kim JungKwon,Chang KemHee,Kim JungHoe 大韓藥學會 2003 大韓藥學會 總會 및 學術大會 Vol.2003 No.2

유기동물 후원을 위한 가상입양 서비스 경험 디자인

문윤정(Yunjeong Mun),이은지(Eunji Lee),장원영(Wonyoung Jang),한지연(Jiyeon Han),홍동식(Dongsik Hong) 한국디자인학회 2018 한국디자인학회 학술발표대회 논문집 Vol.2018 No.11