• Title/Summary/Keyword: Radioactive Waste Management

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Radioanalytical and Spectroscopic Characterizations of Hydroxo- and Oxalato-Am(III) Complexes (방사분석과 분광학을 이용한 Am(III) 가수분해와 옥살레이트 착물 화학종 연구)

  • Kim, Hee-Kyung;Cho, Hye-Ryun;Jung, Euo Chang;Cha, Wansik
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.4
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    • pp.397-410
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    • 2018
  • When considering the long-term safety assessment of spent-nuclear fuel management, americium is one of the most radio-toxic actinides. Although spectroscopic methods are widely used for the study of actinide chemistry, application of those methods to americium chemistry has been limited. Herein, we purified $^{241}Am$ to obtain a highly pure stock solution required for spectroscopic studies. Quantitative and qualitative analyses of purified $^{241}Am$ were carried out using liquid scintillation counting, and gamma and alpha radiation spectrometry. Highly sensitive absorption spectrometry coupled with a liquid waveguide capillary cell and time-resolved laser fluorescence spectroscopy were employed for the study of Am(III) hydrolysis and oxalate (Ox) complexation. $Am^{3+}$ ions under acidic conditions exhibit maximum absorbance at 503 nm, with a molar absorption coefficient of $424{\pm}8cm^{-1}{\cdot}M^{-1}$. $Am(OH)_3(s)$ colloidal particles formed under near neutral pH conditions were identified by monitoring the absorbance at around 506-507 nm. The formation of ${Am(Ox)_3}^{3-}$ was detected by red-shifts of the absorption and luminescence spectra of 4 and 5 nm, respectively. In addition, considerable enhancements of the luminescence intensities were observed. The luminescence lifetime of ${Am(Ox)_3}^{3-}$ increased from 23 to 56 ns, which indicates that approximately six water molecules are replaced by carboxylate ligands in the inner-sphere of the Am(III). These results suggest that ${Am(Ox)_3}^{3-}$ is formed through the bidentate coordination of the oxalate ligands.

Protection for sea-water intrusion by geophysical prospecting & GIS (해수침투 방지를 위한 물리검층과 GIS 활용방안)

  • Han Kyu-Eon;Yi Sang-Sun;Jeong Cha-Youn
    • 한국지구물리탐사학회:학술대회논문집
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    • 2000.09a
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    • pp.54-69
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    • 2000
  • There are groundwater trouble by high-salinity yield inducing sea-water intrusion in Cheju Island. It is used groundwater-GIS(Well-lnfo) in the maintenance and management of groundwater in Cheju Island to grasp groundwater trouble area and cause of high-salinity yield. For 16 wells certain to yield high-salinity, we logged specific electrical conductivity(EC) and tried to get hold of freshwater and saltwater relationship. As result of distribution of $Cl^-$ by depth, it is showed up groundwater trouble by high-salinity yield in the east coastal area and the partly north coastal area. The reason of high-salinity groundwater yield are low-groundwater level by the structure of geology and low-hydraulic gradient etc. There is necessity for management to development and use of groundwater in the high-salinity area, special management area.

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Numerical simulation of the change in groundwater level due to construction of the Giheung Tunnel (기흥터널 건설에 따른 지하수 변화 수치모델링)

  • Lee, Jeong-Hwan;Hamm, Se-Yeong;Cheong, Jae-Yeol;Jeong, Jae-Hyeong;Kim, Ki-Seok;Kim, Nam-Hoon;Kim, Gyoo-Bum
    • The Journal of Engineering Geology
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    • v.20 no.4
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    • pp.449-459
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    • 2010
  • We performed numerical simulations of the excavation of an underground structure (the Giheung Tunnel) in order to evaluate the rate of groundwater flow into the structure and to estimate the groundwater level around the structure. The tunnel was constructed in Precambrian bedrock in Gyeonggi Province, South Korea. Geological and electrical resistivity data, as well as hydraulic test data, were used for the numerical modeling. The modeling took into account the strike-slip faults that cross the southern part of Giheung Tunnel, as these structures influence the discharge of groundwater into the tunnel. The transient modeling estimated a groundwater flow rate into the tunnel of $306\;m^3$/day, with a grout efficiency of 40%, yielding good agreement between the calculated change in groundwater level (6.20 m) and that observed (6.30 m) due to tunnel excavation.

Instrumental Perspectives in Discourse and Practice of Public Engaged ST Governance: Case Study on UK Public Deliberations (시민참여형 과학기술 거버넌스의 논의와 실험에 내재된 도구적 관점: 영국 공론화 사례 중심)

  • Lee, Yunjeong
    • Journal of Technology Innovation
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    • v.23 no.2
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    • pp.1-31
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    • 2015
  • Various concepts and practices of public deliberation have been exercised over the last three decades in western countries for science and technology (ST) governance. There has been a general social consensus for the need of such new governance notwithstanding, ends and means to achieve it varied. Among various rationales, while normative and substantive perspectives are explicitly claimed in public as reasons for public engagement in ST policy making, instrumental perspectives tend to be implicitly arranged by interested parties and still affecting policy significantly. This paper therefore, examines the implications of such instrumental perspectives in public engaged ST governance. To do so, this paper analyses the discourses and practices of public deliberation for ST governance in the UK from the late 1990's until the mid 2000's. It examines the proposals made by various policy institutions and two real public deliberations- the GM Dialogue for commercialization of genetically modified crops and the Committee on Radioactive Waste Management(CoRWM)'s programme. This study finds that policy institutions tried to employ public deliberation as strategic instrument for their policy interest, which contrasted with their outwardly claimed rationales of democratic policy making and better quality in decision for ST governance.

Characteristics of Aquifer System and Change of Groundwater Level due to Earthquake in the Western Half of Jeju Island (제주도 서반부의 대수층 체계와 지진에 의한 지하수위 변동 특성)

  • Ok, Soon-Il;Hamm, Se-Yeong;Kim, Bong-Sang;Cheong, Jae-Yeol;Woo, Nam-Chil;Lee, Soo-Hyoung;Koh, Gi-Won;Park, Yun-Seok
    • Economic and Environmental Geology
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    • v.43 no.4
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    • pp.359-369
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    • 2010
  • This study characterizes aquifer system and hydrogeologic property in the western half of Jeju Island where wells were drilled for regional water supply in three sub-areas (northwestern, western, and southwestern sub-areas). The aquifer system of the northwestern sub-area is largely composed of upper high-permeability layer, upper low-permeability layer, lower high-permeability layer, and lower low-permeability layer. On the other hand, the aquifer systems of the western and southwestern sub-areas are mostly composed of upper low-permeability layer, high-permeability layer, and lower low-permeability layer. Transmissivity and specific capacity decrease in the order of the northwestern, western, and southwestern sub-areas. The relationship between specific capacity and the top surface of tuff is negative with a high correlation coefficient of -0.848, indicating that the tuff acts as the bottom of the aquifer. Groundwater level change due to the 2004 Sumatra earthquake is an average of 23.74 cm in the northwestern sub-area, an average of 9.48 cm in the western sub-area, and none in the southwestern sub-area. Further, it is found that groundwater change due to the earthquake has a positive relationship with transmissivity and specific capacity.

Development of Spent Nuclear Fuel Transportation Worker Exposure Scenario by Dry Storage Methods (건식 저장방식별 사용후핵연료 운반 작업자 피폭시나리오 개발)

  • Geon Woo Son;Hyeok Jae Kim;Shin Dong Lee;Min Woo Kwak;Kwang Pyo Kim
    • Journal of Radiation Industry
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    • v.18 no.1
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    • pp.43-52
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    • 2024
  • Currently, there are no interim storage facilities and permanent disposal facilities in Korea, so all spent nuclear fuels are temporarily stored. However, the temporary storage facility is approaching saturation, and as a measure to this, the 2nd Basic Plan for the Management of High-Level Radioactive Waste presented an operation plan for dry interim storage facilities and dry temporary storage facilities on the NPP on-site. The dry storage can be operated in various ways, and to select the optimal dry storage method, the reduction of exposure for workers must be considered. Accordingly, it is necessary to develop a worker exposure scenario according to the dry storage method and evaluate and compare the radiological impact for each method. The purpose of this study is to develop an exposure scenario for workers transporting spent nuclear fuel by dry storage method. To this end, first, the operation procedure of the foreign commercial spent nuclear fuel dry storage system was analyzed based on the Final Safety Analysis Report (FSAR). 1) the concrete overpack-based system, 2) the metal overpack-based system, and 3) the vertical storage module-based system were selected for analysis. Factors were assumed that could affect the type of work (working distance, working hours, number of workers, etc.) during transportation work. Finally, the work type of the processes involved in transporting spent nuclear fuel by dry storage method was set, and an exposure scenario was developed accordingly. The concrete overpack method, the metal overpack method, and the vertical storage module method were classified into a total of 31, 9, and 23 processes, respectively. The work distance, work time, and number of workers for each process were set. The product of working hours and number of workers (Man-hour) was set high in the order of concrete overpack method, vertical storage module method, and metal overpack method, and short-range work (10 cm) was most often applied to the concrete overpack method. The results of this study are expected to be used as basic data for performing radiological comparisons of transport workers by dry storage method of spent nuclear fuel.

The volcanic aspect on determining Site of nuclear power plant in Indonesia: Gap analysis between standard and regulations

  • Widjanarko;Budi Santoso;Rismiyanto;Kurnia Anzhar;Joko Waluyo;Gustini H. Sayid;Khusnul Khotimah;Nicholas Bertony Saputra;Agus Teguh Pranoto;Hadi Suntoko;Siti Alimah;Sriyana;Roni Cahya Ciputra;Alfitri Meliana
    • Nuclear Engineering and Technology
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    • v.56 no.7
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    • pp.2875-2880
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    • 2024
  • The development of nuclear power plants is in three phases. The first phase is a consideration before the decision on the NPP construction program is approved, the second phase is the preparatory work for making contracts and preparing for the construction of NPP after the NPP construction policy is approved, and the third phase is contracting, licensing and building the first NPP. As a volcanically active country, Indonesia contains over 130 active volcanoes that are part of the Pacific Ring of Fire. The volcanic aspect is one of the safety factors considered while deciding the location of an NPP. Research on the potential of natural external risks to the determination of nuclear power plants in Indonesia, including the volcanic aspect, has been conducted based on the safety reference or safety guide of the IAEA and the Nuclear Energy Regulatory Body (BAPETEN) Regulation. Due to technological advancements, safety needs have evolved so the existing Indonesia National Standard (SNI) must be updated to comply with BAPETEN regulations. The substance in SNI 18-2034-1990 relating to volcanic features seems less relevant in actual conditions, given that more complete and exact criteria for determining a site guarantee the safety and health of residents and surrounding the environment site. The study intends to conduct a gap analysis of volcanic issues in SNI and volcanic regulations. The method used is identification requirements for volcanic aspects in SNI 18-2034-1990 about Determining Site of Nuclear Reactor Guidance with BAPETEN Chairman Regulation (BCR) number 4 of 2018 about Nuclear Installation Site Evaluation Safety Provisions and BCR number 5 of 2015 about Evaluation of Nuclear Installation Sites for Volcanic Aspects, and analysis uses a qualitative method of inductive techniques. The outcome of this research applies to suggesting a revision of SNI number 18-2034-1990, especially the volcanic aspect.

Alternative Concept to Enhance the Disposal Efficiency for CANDU Spent Fuel Disposal System (CANDU 사용후핵연료 처분시스템 효율향상 개념 도출)

  • Lee, Jong-Youl;Cho, Dong-Geun;Kook, Dong-Hak;Lee, Min-Soo;Choi, Heui-Joo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.9 no.3
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    • pp.169-179
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    • 2011
  • There are two types of nuclear reactors in Korea and they are PWR type and CANDU type. The safe management of the spent fuels from these reactors is very important factor to maintain the sustainable energy supply with nuclear power plant. In Korea, a reference disposal system for the spent fuels has been developed through a study on the direct disposal of the PWR and CANDU spent fuel. Recently, the research on the demonstration and the efficiency analyses of the disposal system has been performed to make the disposal system safer and more economic. PWR spent fuels which include a lot of reusable material can be considered being recycled and a study on the disposal of HLW from this recycling process is being performed. CANDU spent fuels are considered being disposed of directly in deep geological formation, since they have little reusable material. In this study, based on the Korean Reference spent fuel disposal System (KRS) which was to dispose of both PWR type and CANDU type, the more effective CANDU spent fuel disposal systems were developed. To do this, the disposal canister for CANDU spent fuels was modified to hold the storage basket for 60 bundles which is used in nuclear power plant. With these modified disposal canister concepts, the disposal concepts to meet the thermal requirement that the temperature of the buffer materials should not be over $100^{\circ}C$ were developed. These disposal concepts were reviewed and analyzed in terms of disposal effective factors which were thermal effectiveness, U-density, disposal area, excavation volume, material volume etc. and the most effective concept was proposed. The results of this study will be used in the development of various wastes disposal system together with the HLW wastes from the PWR spent fuel recycling process.