• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.2
• /
• pp.223-230
• /
• 2013

When a new nuclear fuel is developed, an irradiation test needs to be carried out in the research reactor to analyze the performance of the new nuclear fuel. In order to check the performance of a nuclear fuel during the irradiation test in the test loop of a research reactor, sensors need to be attached in and out of the fuel rod and connect them with instrumentation cables to the measuring device located outside of the reactor pool. In particular, to check the temporary temperature change at the center of a nuclear fuel during the irradiation test, a thermocouple should be instrumented at the center of the fuel rod. Therefore, a hole needs to be made at the center of fuel pellet to put in the thermocouple. However, because the hardness and the density of a sintered $UO_2$ pellet are very high, it is difficult to make a small fine hole on a sintered $UO_2$ pellet using a simple drilling machine even though we use a diamond drill bit made by electro deposition. In this study, an automated drilling machine using a CVD diamond drill has been developed to make a fine hole in a fuel pellet without changing tools or breakage of workpiece. A sintered alumina ($Al_2O_3$) block which has a higher hardness than a sintered $UO_2$ pellet is used as a test specimen. Then, it is verified that a precise hole can be drilled off without breakage of the drill bit in a short time.

• Nuclear Engineering and Technology
• /
• v.55 no.7
• /
• pp.2687-2696
• /
• 2023

The fuel operating ranges of fusion tokamak-based power plants are estimated using the improved engineering breakeven equation. The Lawson criterion equations are derived in the form of a triple product with a focus on engineering breakeven and the subbreakeven operating range. The relationship of fuel parameters to the power plant net efficiency is outlined. Analysis shows that the operating ranges of the suitable fuel parameters form a closed area, the size of which affects the net efficiency of the power plant. The obtained fuel operating ranges confirm the well-known fact that DT fuel is currently the only fusion fuel useable in tokamak-based fusion power plants. It is also shown that the energy utilization of pB fuel is possible in the subbreakeven operating range but is conditioned by the very high efficiency of the power plant equipment. For the utilization of DD, DHe3, and pB fuels, the required magnetic fields are indicatively estimated.

• Journal of Nutrition and Health
• /
• v.29 no.7
• /
• pp.772-777
• /
• 1996

The purpose of this study was to investigate the effect of vitamin B2 deficiency on the utilization and recuperation of fuel in exercising rats. Thirthy six rats were fed either a vitamin B2 deficient diet (-B2) or a control diet (+B2) for 3 weeks and then subdivided into 3 groups : non-exercise group(NE), exercise group (ES), exercise and recuperation group (ER). ES group were exercised on treadmill (10$^{\circ}$, 0.5-0.8km/h) for 2 hours and ER group were recuperated three days with the respective diet after exercise. Glucose (GLU), glycogen(GLY), protein(PRO), triglyceride(TG) and free fatty acid(FFA) were compared in plasma(P), liver(L) and skeletal muscle(M) of rats. Compared to + B2 rats, in NE group, the level of P-GLU and L-GLU of -B2 rats was lower, L-PRO and M-GLY was higher and there were no differences in P-PRO, P-FFA, L-TG and M-TG. In ES group, the level of P-GLU was lower, P-FFA was higher and there were no differences in P-PRO, P-TG, L-GLU, L-TG, M-GLY, M-TG and M-PRO. In ER groups, the level of P-GLU and L-TG was lower, P-FFA was higher and there were no differences in P-PRO, P-TG, L-GLY, L-PRO, M-GLY, M-TG and M-PRO. These results suggest that a vitamin B2 deficiency may impair the utilization of stored fuel during exercise suggest that a vitamin B2 deficiency may impair the utilization of stored fuel during exercise and may lead a sluggish recuperation related to fuel stores after exercise.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.557-560
• /
• 2005

Production, utilization and related regulation of refuse derived fuel in Korea have been discussed in this paper. Also, the expected future of RDF has been discussed. Although the interest about RDF has been increased continuously , there are many things that must be solved for the development of RDF industry. Compared with other developed country, inadequacy of regulation about RDF and the lack of possible utilization facility make the limitation for the development of RDF industry.

• Journal of Hydrogen and New Energy
• /
• v.33 no.4
• /
• pp.363-371
• /
• 2022

In this study, the operation characteristics of the internal reforming type molten carbonate fuel cell (MCFC) were studied using computational fluid dynamics (CFD) analysis according to the steam to carbon ratio (S/C ratio), operating temperature, and gas utilization. From the simulation results, the distribution of gas composition due to the electrochemical reaction and the reforming reaction was predicted. The internal reforming type showed a lower temperature difference than the external reforming type MCFC. As the operating temperature decreased, less hydrogen was produced and the performance of the fuel cell also decreased. As the gas utilization rate decreased, more gas was injected into the same reaction area, and thus the performance of the fuel cell increased.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2022.11a
• /
• pp.160-161
• /
• 2022

Hydrogen is bridge fuel with high energy content and environmentally friendly to satisfy the stringent IMO regulation relating to greenhouse gas (GHG) emissions. There is growing interest in hydrogen in numerous nations and regions illustrated by an extensive range of research and development in technology. Regarding maritime applications, researchers have recognized the utilization of hydrogen as a fuel for fuel cells, a device that converts the chemical energy of the fuel to electrical energy. Solid oxide fuel cell (SOFC), with high working temperature, is easy to combine with the waste heat recovery cycles/devices to increase output power and thermodynamic performances as well. Furthermore, the cold energy from liquid hydrogen supplied to SOFC can also be used to generate more power. In this study, we proposed a SOFC integrated system with the idea of combining the waste heat recovery from the SOFC exhaust stream and cold energy utilization from LH₂. The designation is aimed to target small-scale vessel which uses electric propulsion for short distances voyage.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.395-396
• /
• 2005

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2001.05b
• /
• pp.85-91
• /
• 2001

This paper provides a case study of landfill gas (LFG) utilization fer direct use as process fuel, and for electrical power generation at restored landfills in the Hong Kong Special Administrative Region of China (HKSAR). The paper specifically covers the LFG utilization schemes, which are required under landfill restoration contracts at the Shuen Wan and Urban Landfills. These contracts provide for the restoration and aftercare of six landfills, and are administered by the Environmental Protection Department (EPD) of the Hong Kong Government. The LFG utilization scheme at the Shuen Wan Landfill incorporates the direct use of LFG by compressing and dehumidifying the LFG prior to conveyance through a 1.6-kilometer (1-mile) pipeline. The pipeline provides an alternate fuel source to naphtha during process heating for gas production at the Tai Po Gas Production Plant of the Hong Kong and China Gas Limited (HKCC). The LFG utilization scheme at the Jordan Valley Landfill (one of the Urban Landfills) beneficially uses the LFG as fuel for electrical power generation with reciprocating internal combustion engines. The LFG is compressed, cooled, and filtered prior to delivery to two engine/generator sets. This system provides power to operate the leachate pre-treatment plant, which processes leachate from all of the Urban Landfill sites. The case study will examine the technical and non-technical considerations, including harriers, for developing, designing and implementing the LFG utilization projects in Hong Kong. Specific regulatory considerations and external governmental agency approvals are discussed, including the requirement to register as a gas-producing utility. While the paper focuses on LFG utilization applications in Hong Kong, many of the considerations discussed are also applicable to development of LFG utilization in other regions of Asia.

• Journal of Distribution Science
• /
• v.18 no.9
• /
• pp.67-75
• /
• 2020

Purpose: The purpose of this study is to enhance sales promotion efficiency for using solid refuse fuel facilities. Renewable energy technology using Solid Refuse Fuel (SRF) is an economic efficiency technology that recovers waste by burning various wastes. A survey on the pollutants discharged from the solid fuels facilities was investigated so that the SRF facilities could be expanded, distributed and reflected in the policy. Research design, data, and methodology: In this study, 9 business sites using SRF and Bio-SRF as main raw materials were investigated for 2 years. The characteristics of target business sites such as the type of fuel used, combustion method, combustion temperature, daily fuel consumption and environmental prevention facilities were studied. Results: The average pollution & ammonia concentration of Bio-SRF facilities was found to be 88.15% higher than that of SRF facilities. But the average acetaldehyde concentration of SRF facilities was found to be 88.15% higher than that of Bio-SRF facilities. Conclusions: The main issue is how much electric power generation using combustible materials affects air pollution. The waste recycling law provides the standard value according to the fuel property, but there is a considerable gap with the mixed fuel. Therefore, for efficient utilization of facilities using solid fuel products, additional research is needed to improve the distribution structure of exhaust pollutants is needed.

• Nuclear Engineering and Technology
• /
• v.40 no.6
• /
• pp.517-526
• /
• 2008

The widespread concern regarding the management of spent fuel that mainly contributes to nuclear waste has led to the development of the sodium-cooled fast reactor (SFR) as one of the most promising future types of reactors at both national and international levels. Various reactor deployment scenarios with SFR introductions with different conversion ratios in the existing PWR-dominant nuclear fleet have been assessed to optimize the SFR deployment strategy to replace PWRs with the view toward a reduction in the level of spent fuel as well as efficient uranium utilization through its reuse in a closed fuel cycle. An efficient reactor deployment strategy with the SFR introduction starting in 2040 has been drawn based on an SFR deployment strategy in which burners are deployed prior to breakeven reactors to reduce the amount of PWR spent fuel substantially at the early deployment stage. The PWR spent fuel disposal is reduced in this way by 98% and the cumulative uranium demand for PWRs to 2100 is projected to be 445 ktU, implying a uranium savings of 115 ktU. The SFR mix ratio in the nuclear fleet near the year 2100 is estimated to be approximately 35-40%. PWRs will remain as a main power reactor type until 2100 and SFRs will support waste minimization and fuel utilization.