• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1206-1212
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• 2022

Cold-crucible induction melting (CCIM) technology has been intensively studied as an advanced vitrification process for the immobilization of highly radioactive waste. This technology uses high-frequency induction to melt a glass matrix and waste, while the outer surface of the crucible is water-cooled, resulting in the formation of a frozen glass layer (skull). In this study, for the fabrication of borosilicate glass waste form, CCIM operation test with 60 kg of glass per batch was conducted using surrogate wastes composed of Cs, Sr, and Nd as a representative of highly radioactive nuclides generated during spent nuclear fuel management. A 60 kg-scale glass waste form was successfully fabricated through melting and draining processes using a CCIM system, and its physicochemical properties were analyzed. In particular, to enhance the controllability and reliability of the draining process, an air-cooling drain control method that can control draining through air-cooling near drain holes was developed, and its validity for draining control was verified. The method can offer controllability on various draining processes, such as molten salt or molten metal draining processes, and can be applied to a process requiring high throughput draining.

• 한국환경과학회지
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• 제5권2호
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• pp.221-227
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• 1996

The objectives of this study are to examine combustion characteristics of E.V.A. and rubber wastes by fixed-bed incinerator, The results are as follows. Combustion temperature with time rises rapidly, and mass of E.V.A. reduces at short time in E.V.A. combustion. In variation of air-fuel ratio (m), ice ideal values of m of E.V.A. and rubber are 2.5, 1.5 respectively. Mixed-waste combustion is more economic than single E.V.A. combustion, because we can get high combustion efficiency (94.0~99.0%) at 2.0 air-fuel ratio of mixed-waste combustion. Removal efficiencies of SO2 at cooling tower are about 20%. The combustion efficiencies of rubber are over 98.0% according to the experimental conditions.

• 자원리싸이클링
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• 제9권1호
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• pp.27-35
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• 2000

본 연구에서는 150kg/batch(승용차용 타이어 기준) 규모의 건류가스화 장치를 이용하여 페타이어와 7종류의 폐합성수지에 대한 건류가스화 실험을 폐기물 종류별 건류가스화 특성을 파악하고, 건류시간 및 1차 공기량에 따른 건류가스의 발생량과 성분 조성 등의 변화 경향등을 분석하였다. 페타이어의 경우 반응기 내부에서 연소영역과 가스화 영역의 뚜렷한 구별이 확인되었고, 건류용 1차 공기량에 대해 1.05~1.35 배의 비율로 발생되는 생성가스는 비가연성성분 이외에 CO, $H_2$, $C_1$~$C_7$ 범위의 탄화수소로 구성되었으며, 정상상태에서는 1.500~300 kcal/N$\textrm{m}^3$. 종말처리 단계에서는 250~500kcal/N$\textrm{m}^3$의 발영량을 각각 나타냈다. 페합성 수지류는 생성가스의 온도변화가 심하고, $N_2$, $CO_2$, $O_2$의 구성비율이 85%이상인 건류생성가스는 원료폐기물이 가진 열량의 10~35%에 해당하는 300~2,900kcal/N$\textrm{m}^3$ kcal/Nm의 발열량을 보유하였다.

• 대한설비공학회지:설비저널
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• 제38권5호
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• pp.4-11
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• 2009

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2008년도 추계학술대회 논문집
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• pp.47-49
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• 2008

• 터널과지하공간
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• 제19권1호
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• pp.11-18
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• 2009

원자력 에너지를 이용할 때 필연적으로 방사성 폐기물이 발생된다. 방사성폐기물을 처분하기 위한 처분장은 주로 외부와 단절된 지하공간을 이용하며 방사성폐기물을 거치할 수 있는 Diagonal system을 기본으로 하며, 시스템에 발생된 열을 재기하기 위해서는 환기시설이 필수적이다. 따라서 본 연구에서는 Diagonal system에서 공기 조절기의 위치와 크기를 변화시켜 Diagonal branch로 흐르는 공기의 풍속을 측정하였다. 그 결과 Diagonal branch를 지나는 풍속은 중간에 위치한 공기 조절기의 크기에 관계없이 처음과 마지막 공기 조절기의 크기에 의해서 결정되었다. 따라서 일정한 유랑을 Diagonal branch에 주입하기 위해서는 처음과 마지막 공기 조절기를 설치하여 총 유량을 결정한 후 중간지점에 공기 조절기를 설치하여야 한다.

• 산업기술연구
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• 제17권
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• pp.227-232
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• 1997

This study was conducted to evaluate durability of concrete which are increasingly demanded recently. Concrete durability properties incorporating waste foundry sand was performed with the variable of W/C ratio, Sand/Waste foundry sand ratio and Air entrainment-Non air entrainment. Cylinder specimens were made and subjected to freezing and thawing cycle at $-18^{\circ}C$ and $4^{\circ}C$. Dynamic modulus of elasticity were evaluated as F/T cycle increase. The results show that decreasing W/C ratio and AE concrete makes improved resistance of freezing and thawing improved. Especially, resistance of freezing and thawing is improved by Fine aggregate/Waste foundry sand ratio which is 50%, 25%, 0% in a row.

• 대한기계학회논문집
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• 제19권12호
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• pp.3372-3381
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• 1995

An equilibrium analysis was carried out to determine principal species of heavy metals in waste incineration and their behaviors with variation of temperature, chlorine concentration, excess air ratio, and C/H ratio. The waste was assumed as a compound of hydrocarbon fuel, chlorine, and metals. Calculated results showed that the most important parameter to determine the principal species was temperature. Chlorine concentration also affected on mole fractions of the principal species. Generally principal species at high temperature were chlorides while there were some metals of which principal species were oxides. At low temperature mole fractions of the principal species increased, but at high temperature mole fractions of some metal species decreased. C/H ratio of the hydrocarbon fuel and excess air ratio had little effect on mole fractions of the metal species, compared to the temperature and chlorine concentration.

• 설비공학논문집
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• 제12권9호
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• pp.853-859
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• 2000

In this study, low temperature waste heat recovery heat exchanger was developed using a principle of self-excited oscillating heat pipe. The heat exchanger of serpentine type was composed of extruded flat aluminum tube with 6 channels (3 nm$\times$ 2.75nm) and louvered fin. The heat transfer area density of heat exchanger was $331.9 m^2/m^3$. Working fluid is R141b and charge ratio was 40% by volume. Heat transfer rate and the effectiveness of heat exchanger was primary concern of this study. As a result, the effectiveness of heat exchanger was about 0.4-0.67, and recovered waste heat rate was about 4.5 kW per one unit of heat exchanger.

• Environmental Analysis Health and Toxicology
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• 제16권2호
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• pp.75-84
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• 2001

Differences in risk perception on major environmental issues between general public and environmental experts were investigated in this study. Questionnaire surveys were conducted to samples from general public and environmental experts during March and April, 2000. Total number of responses was 1,126 including 773 persons from general public and 353 experts. Risk perceptions on 26 environmental issues were related with the need to regulate each issue, controllability, experience, political views, interest in environmental problem, satisfaction of environment, severity of environmental pollution. There was statistically significant difference in risk perceptions between general public and experts. Overall, general public was likely to perceive risks associated with environmental problem, as well as social need to regulate these problems more than experts. The issues with high risk perception and need to regulate were 'automobile exhaust', 'industrial air pollution', ocean pollution by industrial waste and oil exhaust', 'air pollution by chemicals', 'surface water pollution by waste from household', 'industrial and hospital waste', 'surface water pollution by pesticide'and'sewage and food waste'. Consequently, it seems necessary to manage these issues, prior to others.