• Title/Summary/Keyword: Waste form

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A Study on Deliberative type of citizen participation: The case of The case of A Food Waste Recycling Facility in Ulsan City, Korea (숙의적 시민참여 모델 연구: 울산시 북구 음식물자원화시설 건립 사례)

  • Cho, Hyun-Suk
    • Journal of Science and Technology Studies
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    • v.6 no.1 s.11
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    • pp.1-30
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    • 2006
  • This paper is to analyse the case of citizen participation employed in the local government, Buk-gu (Northern District) in the city of Ulsan, Korea. A kind of deliberative type of citizen participation named' citizen jury' was exercised to resolve an environmental conflict between Buk-gu government and its residents. The conflict was caused by the construction of a food waste recycling facility near by some residential areas in Buk-gu. Theoretically this paper makes a typology of citizen participation methods. Two criteria are employed. First of all, lay citizens are the primary participant or not? Secondly, interactive communication is feasible or not among participants in the process of citizen participation. Four generic types of citizen participation are sorted out: technocratic, pluralist, direct/participatory, and deliberative type. Especially deliberative type of citizen participation is based on an idea of deliberative democracy. This paper argues that the case of citizen participation employed in Buk-gu belongs to deliberative type of citizen participation. The argument is based on the following reasons. Firstly, primary participants in deliberation process can be considered as lay citizens though they are selected form local NGOs and religious groups. According to a survey, most of participants said that they would participate in the process of deliberation in the capacity of lay citizens though they were selected by their own groups. Secondly, the citizen participation process was deliberately designed and implemented to facilitate competence of primary participants and fairness in the deliberation. Viewed from this analysis, this Buk-gu case can be safely considered an innovative method of citizen participation which is also very successful in resolving intractable environmental conflict in the local government.

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R&D Review on the Gap Fill of an Engineered Barrier for an HLW Repository (고준위폐기물처분장 공학적방벽의 갭채움재 기술현황)

  • Lee, Jae Owan;Choi, Young-Chul;Kim, Jin-Seop;Choi, Heui-Joo
    • Tunnel and Underground Space
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    • v.24 no.6
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    • pp.405-417
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    • 2014
  • In a high-level waste repository, the gap fill of the engineered barrier is an important component that influences the performance of the buffer and backfill. This paper reviewed the overseas status of R&D on the gap fill used engineered barriers, through which the concept of the gap fill, manufacturing techniques, pellet-molding characteristics, and emplacement techniques were summarized. The concept of a gap fill differs for each country depending on its disposal type and concept. Bentonite has been considered a major material of a gap fill, and clay as an inert filler. Gap fill was used in the form of pellets, granules, or a pellet-granule blend. Pellets are manufactured through one of the following techniques: static compaction, roller compression, or extrusion-cutting. Among these techniques, countries have focused on developing advanced technologies of roller compression and extrusion-cutting techniques for industrial pellet production. The dry density and integrity of the pellet are sensitive to water content, constituent material, manufacturing technique, and pellet size, and are less sensitive to the pressure applied during the manufacturing. For the emplacement of the gap fill, pouring, pouring and tamping, and pouring with vibration techniques were used in the buffer gap of the vertical deposition hole; blowing through the use of shotcrete technology and auger placement and compaction techniques have been used in the gap of horizontal deposition hole and tunnel. However, these emplacement techniques are still technically at the beginning stage, and thus additional research and development are expected to be needed.

Analysis on the Generation Characteristics of $^{14}C$ in PHWR and the Adsorption and Desorption Behavior of $^{14}C$ onto ion Exchange Resin (중수로 원전$^{14}C$ 발생 특성 및 이온교환수지에 의한 $^{14}C$$\cdot$착탈 거동 분석)

  • 이상진;양호연;김경덕
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.147-157
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    • 2004
  • The production of $^{14}C$ occurs in the Moderator(MOD), Primary Heat Transport System (PHTS), Annulus Gas System(AGS) and Fuel in the CANDU reactor. Among the four systems, The MOD system is the largest contributor to $^{14}C$ production(approximately 94.8%). $^{14}C$ is distributed of $^{14}CO_2$, $H_2^{14}CO_3$, $H^{14}{CO_3}^-$ and $^{14}{CO_3}^{2-}$ species as a function of the pH of water. Of these species, $H_2^{14}CO_3$ and $H^{14}{CO_3}^-$ form are predominant because the pH of MOD system is > 5. In this paper, adsorption-desorption characteristics of bicarbonate ion (${HCO_3}^-$) by IRN 150 resin was investigated. ${HCO_3}^-$ ion existed in neutral condition(app. pH 7)was reacted with ion exchange resin (IRN-150) and saturated with it. Then $NaNO_3$ and $Na_3PO_4$ solutions selected as extraction materials were used to make an investigation into feasibility of ${HCO_3}^-$ extraction from resin saturated with ${HCO_3}^-$. Desorption of $CO^{2+}$ and $Cs^+$ ion by $Na^+$ ion was not occurred, and desorption of ${HCO_3}^-$ ion by ${NO_3}^-$ and ${PO_4}^{3-}$ was occurred slowly. Also, the status of ion exchange which is used in Wolsong NPPs and generation of spent resin yearly were surveyed.

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Migration and Retardation Properties of Uranium through a Rock Fracture in a Reducing Environment (환원환경에서 암반 균열을 통한 우라늄 이동 및 지연 특성)

  • Baik, Min-Hoon;Park, Chung-Kyun;Cho, Won-Jin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.2
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    • pp.113-122
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    • 2007
  • In this study, uranium migration experiments have been performed using a natural groundwater and a granite core with natural fractures in a glove-box constructed to simulate an appropriate subsurface environment. Groundwater flow experiments using the non-sorbing anionic tracer Br were carried out to analyze the flow properties of groundwater through the fracture of the granite core. The result of the uranium migration experiment showed a breakthrough curve similar to that of the non-sorting Br. This result may imply that uranium migrates as anionic complexes through the rock fracture since uranium can form carbonate complexes at a given groundwater condition. The distribution coefficient $K_d$ of the uranium between the groundwater and the fracture filling material was obtained as low as 2.7 mL/g from a batch sorption experiment. This result agrees well with the result from the migration experiment, showing a faster elution of the uranium through the rock fracture. In order to analyze retardation properties of the uranium through the rock fracture, the retardation factor $R_d({\sim}16.2)$ was obtained by using the $K_d$ obtained from the batch sorption experiment and it was compared with the $R_d({\sim}14.3)$ obtained by using the result from the uranium migration experiment. The values obtained from the both experiments were very similar to each other. This reveals that the retardation of the uranium is mainly occurred by the fracture filling material when the uranium migrates through the fracture of a granite core.

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Applicability of SRSL(Self-Recovering Sustainable Liner) to the Landfill Final Cover System (SRSL(Self Recovering Sustainable Liner)재의 매립지 최종복토층에 대한 활용성 검토)

  • Kwon, Oh-Jung;Seo, Min-Woo;Hong, Soo-Jung;Park, Jun-Boum;Park, Soo-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.453-460
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    • 2004
  • To prevent penetration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Conventional designs of landfill covers uses geotextiles such as geomembrane and GCL, and clay liners to lower the permeability of final covers of landfill sites. However, differential settlement and the variation of temperature in landfill sites cause the development of cracks or structural damage inside the final cover and it is also difficult to obtain clay - the main material of the compacted clay liner in Korea. Thus the former final cover system that suggests geomembrane and GCL or compacted clay liner has several limitations. Therefore, an alternative method is necessary and one of them is the application of SRSL(self-Recovering Sustainable Liner) material. SRSL is two different layers consist of individual materials that react with each other and form precipitates, and with this process lowers the permeability of the landfill final cover. SRSL generally is made up of two layers, so that when a internal crack occurs the reactants of the two layers migrate towards the crack and heal it by forming another liner. In this study the applicability of SRSL material for landfill final cover was examined by performing; (1) jar test to verify the formation of precipitate in the mixture of each reactants, (2) falling head test considering the field stress in order to confirm the decrease of permeability or prove that the hydraulic condctivity is lower than the regulations, (3) compression tests to judge weather if the strength satisfies the restricts for landfills, (4) freeze/thaw test to check the applicability of SRSL for domestic climate. In addition, the application of waste materials in the environmental and economical aspect was inspected, and finally the possibility of secondary contamination due to the waste materials was examined by performing elution tests.

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Nutrient Budget and Dam Effluence in Asan Bay (아산만 내 방조제 배출수와 영양염의 물질수지)

  • Jeong, Yong Hoon;Cho, Min Kyun;Lee, Dong Gi;Doo, Sun Min;Choi, Hyun Soo;Yang, Jae Sam
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.5
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    • pp.468-482
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    • 2016
  • To understand variations in the seawater quality of Asan Bay over four seasons form December 2011 to February 2013, we applied two methods: an in-situ observation of water quality and a comparison study of nutrient budgets among three parts (No. 1, 2, and 3) of Asan Bay. We found a significantly high nutrient concentration in the central part of the bay (No. 2) in July 2012 both in the mass balance study and in situ observation. We presumed the source of these nutrients to be both benthic effluence from old dam reservoirs and incompletely-treated municipal waste-water. This elevated nutrient concentration in the central part of Asan Bay (No. 2) expended to off-shore area and eventually triggered an intense Chl-a concentration in Asan Bay. Based on this result, we suggest improved waste-water quality control around the drainage area of Asan Bay.

Study on recovery of $Na_{2}SiF_6$ and acetic acid from waste acid produced during semiconductor wafer process (반도체 웨이퍼 제조공정(製造工程) 중 발생불산(發生廢酸)으로부터 $Na_{2}SiF_6$ 및 초산의 회수(回收)에 관한 연구(硏究))

  • Kim, Hyun-Sang;Kim, Ju-Yup;Lee, Hyang-Sook;Shin, Chang-Hoon;Kim, Jun-Young;Bae, Woo-Keun;Ahn, Jong-Kwan
    • Resources Recycling
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    • v.17 no.5
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    • pp.3-10
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    • 2008
  • We researched recycle of mixed waste acids including HF, $CH_{3}COOH$, $HNO_3$ produced during semiconductor wafer process. At first, we recovered HF in form of $Na_{2}SiF_6$ by precipitation using $NaNO_3$ and $Na_{2}SiO_3$. Concentration of HF was made down from 110 g/L, initial concectration, to 0.5 g/L and Recovery rate of HF was 99.5%. After recovery of HF, concentration of $HNO_3$ and $CH_{3}COOH$ is 498 g/L, 265 g/L respectively. From that mixed acid, we recovered $CH_{3}COOH$ using 2 stages of fractional distillation. In first stage, $CH_{3}COOH$ was distilled for separation from $HNO_3$. And in second stage, we recoverd refined $CH_{3}COOH$ by using fractional distillation for removing a little amount of $HNO_3$ in $CH_{3}COOH$ vapor. The concentration of recovered $CH_{3}COOH$ in second stage is 20% and finally recovery rate of $CH_{3}COOH$ is about 87.5%.

Effects of Gas Injection on the Recovery of Copper Powder from Industrial Waste Water in Fluidized - Bed Electrolytic Reactors (유동층 전극반응기에서 기체의 유입이 산업폐수로부터 동입자의 회수에 미치는 영향)

  • Song, Pyung-Seob;Son, Sung-Mo;Kang, Yong;Kim, Seung-Jai;Kim, Sang Done
    • Applied Chemistry for Engineering
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    • v.16 no.4
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    • pp.485-490
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    • 2005
  • Effects of gas injectino on the copper recovery form industrial waste water in a fluidized-bed electrolytic reactor were investigated. Effects of gas injection on the individual phase holdup and efficiency of copper recovery for given operating variables such as liquid and gas velocity (0.1~0.4 cm/s), current density ($2.0{\sim}3.5A/dm^2$) and amount of fluidized solid particles (1.0~4.0 wt%) were examined. The solid particle, whose diameter and swelling density were 0.5 mm and $1100kg/m^3$, respectively, was made of polystylene and divinyl benzene. It was found that the holdup of gas and solid phases increased, but that of the liquid phase decreased with increasing velocity of gas injected into the reactor. With increasing gas and/or liquid velocity and increasing amount of fluidized particles is not needed, the rate of copper recovery increased to a maximum value of and subsequently decreased. The recovery rate of copper increased almost linearly with increasing current density in accordance with Faraday's law.

Study of the Formation of Eutectic Melt of Uranium and Thermal Analysis for the Salt Distillation of Uranium Deposits (우라늄 전착물의 염증류에 대한 우라늄 공정(共晶) 형성 및 열해석 연구)

  • Park, Sung-Bin;Cho, Dong-Wook;Hwang, Sung-Chan;Kang, Young-Ho;Park, Ki-Min;Jun, Wan-Gi;Kim, Jeong-Guk;Lee, Han-Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.1
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    • pp.41-48
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    • 2010
  • Uranium deposits from an electrorefining process contain about 30% salt. In order to recover pure uranium and transform it into an ingot, the salts have to be removed from the uranium deposits. Major process variables for the salt distillation process of the uranium deposits are hold temperature and vacuum pressure. Effects of the variables on the salt removal efficiency were studied in the previous study[1]. By applying the Hertz-Langmuir relation to the salt evaporation of the uranium deposits, the evaporation coefficients were obtained at the various conditions. The operational conditions for achieving above 99% salt removal were deduced. The salt distilled uranium deposits tend to form the eutectic melt with iron, nickel, chromium for structural material of salt evaporator. In this study, we investigated the hold temperature limitation in order to prevent the formation of the eutetic melt between urnaium and other metals. The reactions between the uranium metal and stainless steel were tested at various conditions. And for enhancing the evaporation rate of the salt and the efficient recovery of the distilled salt, the thermal analysis of the salt distiller was conducted by using commercial CFX software. From the thermal analysis, the effect of Ar gas flow on the evaporation of the salt was studied.

A Study on the Architecture Modeling of Information System using Simulation (시뮬레이션을 이용한 정보시스템 아키텍쳐 모델링에 관한 연구)

  • Park, Sang-Kook;Kim, Jong-Bae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.455-458
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    • 2013
  • The conventional design of the information system architecture based on the personal experience of information systems has been acted as a limit in progress utilizing appropriate resource allocation and performance improvements. Architecture design depending on personal experience makes differences in variance of a designer's experience, intellectual level in related tasks and surroundings, and architecture quality according to individual's propensity. After all these problems cause a waste of expensive hardware resources. At working place, post-monitoring tools are diversely developed and are running to find the bottleneck and the process problems in the information operation. However, there are no simulation tools or models that are used for expecting and counteracting the problems at early period of designing architecture. To solve these problems we will first develop a simulation model for designing information system architecture in a pilot form, and will verify validity. If an error rate is found in the permissible range, then it can be said that the simulation reflects the characteristic of information system architecture. After the model is developed in a level that can be used in various ways, more accurate performance computation will be able to do, getting out of the old way relying on calculations, and prevent the existence of idle resources and expense waste that comes from the wrong design of architecture.

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