• 공업화학
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• 제20권4호
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• pp.411-415
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• 2009

고점도인 최저급 폐유를 난방유로 대체하기 위하여 폐유에 희석용제로 경유,벙커C유를 이용하여 일정비율로 혼합한 후 연료 특성을 분석하였다. 혼합조건은 교반속도 3400~3600 rpm에서, 반응 시간을 30 s~30 min으로 조절하였고 반응온도는 $75{\pm}5^{\circ}C$로 유지하였다. 벙커C유, 경유를 이용하여 폐유의 점도를 낮춘 결과 최소 81%, 최대 96% 정도 감소되었다. 난방연료로서 폐유 : 벙커C유 : 경유의 최적 혼합 비율은 1 : 1 : 1이었으며 이 경우 인화점 $78^{\circ}C$, 동점도 $20.02mm^{2}/s$, 발열량 9158 kcal/L을 가짐을 확인하였다.

• 방사성폐기물학회지
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• 제21권4호
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• pp.517-529
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• 2023

The objectives of this paper are: (1) to conduct the thermal analyses of the disposal cell using COMSOL Multiphysics; (2) to determine whether the design of the disposal cell satisfies the thermal design requirement; and (3) to evaluate the effect of design modifications on the temperature of the disposal cell. Specifically, the analysis incorporated a heterogeneous model of 236 fuel rod heat sources of spent nuclear fuel (SNF) to improve the reality of the modeling. In the reference case, the design, featuring 8 m between deposition holes and 30 m between deposition tunnels for 40 years of the SNF cooling time, did not meet the design requirement. For the first modified case, the designs with 9 m and 10 m between the deposition holes for the cooling time of 40 years and five spacings for 50 and 60 years were found to meet the requirement. For the second modified case, the designs with 35 m and 40 m between the deposition tunnels for 40 years, 25 m to 40 m for 50 years and five spacings for 60 years also met the requirement. This study contributes to the advancement of the thermal analysis technique of a disposal cell.

• Nuclear Engineering and Technology
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• 제39권6호
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• pp.683-690
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• 2007

Because of increasing concerns regarding global warming and the longevity of oil and gas reserves, the importance of nuclear energy as a major source of sustainable energy is gaining recognition worldwide. To make nuclear energy truly sustainable, it is necessary to ensure not only the sustainability of the fuel supply but also the sustained availability of waste repositories, especially those for high-level radioactive waste (HLW). From this perspective, the effort to maximize the waste loading density in a given repository is important for easing repository capacity problems. In most cases, the loading of a repository is controlled by the decay heat of the emplaced waste. In this paper, a comparison of the decay heat characteristics of HLW is made among the various fuel cycle options. It is suggested that, for a future fast breeder reactor (FBR) cycle, the removal and burning of minor actinides (MA) would significantly reduce the heat load in waste and would allow for a reduction of repository size by half.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.329-330
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• 2009

Food waste contains almost no heavy metals and high fuel ratio 0.14-0.17 that makes it a good candidate for solid fuel. Thermogravimetric analysis showed that volatile matter volatilizes at $200-400^{\circ}C$, and ignition temperature is $460^{\circ}C$. Combustion efficiency measured from energy balance before and after combustion was over 99%. Pulverized fuel made from food waste is a new and renewable energy which contribute to low carbon green economic growth.

• Environmental Engineering Research
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• 제22권2호
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• pp.157-161
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• 2017

Simultaneous treatment of food waste leachate and power generation was investigated in an air-cathode microbial fuel cell. A TCOD removal efficiency of $95.4{\pm}0.3%$ was achieved for an initial COD concentration of 2,860 mg/L. Maximum power density ranged was maximized at $1.86W/m^3$, when COD concentration varied between 60 mg/L and 2,860 mg/L. Meanwhile, columbic efficiency was determined between 1.76% and 11.07% for different COD concentrations. Cyclic voltammetric data revealed that the oxidation peak voltage occurred at -0.20 V, shifted to about -0.25 V. Moreover, a reduction peak voltage at -0.45 V appeared when organic matters were exhausted, indicating that reducible matters were produced during the decomposition of organic matters. The results showed that it was feasible to use food waste leachate as a fuel for power generation in a microbial fuel cell, and the treatment efficiency of the wastewater was satisfied.

• Nuclear Engineering and Technology
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• 제40권3호
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• pp.175-182
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• 2008

The results of process development for the blending of waste salt from the electrorefining of spent fuel with zeolite-A are presented. This blending is a key step in the ceramic waste process being used for treatment of EBR-II spent fuel and is accomplished using a high-temperature v-blender. A labscale system was used with non-radioactive surrogate salts to determine optimal particle size distributions and time at temperature. An engineering-scale system was then installed in the Hot Fuel Examination Facility hot cell and used to demonstrate blending of actual electrorefiner salt with zeolite. In those tests, it was shown that the results are still favorable with actinide-loaded salt and that batch size of this v-blender could be increased to a level consistent with efficient production operations for EBR-II spent fuel treatment. One technical challenge that remains for this technology is to mitigate the problem of material retention in the v-blender due to formation of caked patches of salt/zeolite on the inner v-blender walls.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2019년도 춘계학술논문요약집
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• pp.80-81
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• 2019

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.62-63
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• 2018

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 춘계학술논문요약집
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• pp.65-66
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• 2017

• Nuclear Engineering and Technology
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• 제43권2호
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• pp.149-158
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• 2011

Metal waste generated from the pyroprocessing of 10 MtU of spent fuel was classified by comparing the specific activity of a relevant radionuclide with the limit value of the specific activity specified in the Korean acceptance criteria for a lowand intermediate-level waste repository. A Korean Optimized Fuel Assembly design with a 17${\times}$17 array, an initial enrichment of 4.5 weight-percent, discharge burn-up of 55 GWD/MtU, and a 10-year cooling time was considered. Initially, the mass and volume of each structural component of the assembly were calculated in detail, and a source term analysis was subsequently performed using ORIGEN-S for these components. An activation cross-section library generated by the KENO-VI/ORIGEN-S module was utilized for top-end and bottom-end pieces. As a result, an Inconel grid plate, a SUS plenum spring, a SUS guide tube subpart, SUS top-end and bottom-end pieces, and an Inconel top-end leaf spring were determined to be unacceptable for the Gyeongju low- and intermediate-level waste repository, as these waste products exceeded the acceptance criteria. In contrast, a Zircaloy grid plate and guide tube can be placed in the Gyeongju repository. Non-contaminated Zircaloy cladding occupying 76% of the metal waste was found to have a lower level of specific activity than the limit value. However, Zircaloy cladding contaminated by fission products and actinides during the decladding process of pyroprocessing was revealed to have 52 and 2 times higher specific activity levels than the limit values for alpha and $^{90}Sr$, respectively. Finally, it was found that 88.7% of the metal waste from the 17${\times}$17 Korean Optimized Fuel Assembly design should be disposed of in a deep geological repository. Therefore, it can be summarized that separation technology with a higher decontamination factor for transuranics and strontium should be developed for the efficient management of metal waste resulting from pyroprocessing.