To investigate the impact of forestry projects on the carbon stocks of forests, we estimated the carbon stock change of above-ground and soil before and after forestry projects using forest type maps, forestry project information, and soil information. First, we selected six map sheet with large areas and declining age class based on forest type map information. Then, we collected data such as forest type maps, growth coefficients, soil organic matter content, and soil bulk density of the estimated areas to calculate forest carbon storage. As a result, forest carbon stocks decreased by about 34.1~70.0% after forestry projects at all sites. In addition, compared to reference studies, domestic forest soils store less carbon than the above-ground, so it is judged that domestic forest soils have great potential to store more carbon and strategies to increase carbon storage are needed. It was estimated that the amount of carbon stored before forestry projects is about 1.5 times more than after forestry projects. The study estimated that it takes about 27 years for forests to recover to their pre-thinning carbon stocks following forestry projects. Since it takes a long time for forests to recover to their original carbon stocks once their carbon stocks are reduced by physical damage, it is necessary to plan to preserve them as much as possible, especially for highly conservative forests, so that they can maintain their carbon storage function.

Carbon black is a material in the form of fine black powder obtained by incomplete combustion or pyrolysis of hydrocarbons, and is composed of 90-99% carbon, and the rest is composed of hydrogen and oxygen. In the event of an emergency during the manufacture of carbon black, the generated tail gas should be safely discharged through an emergency line to prevent fire, explosion, and environmental pollution accidents caused by the tail gas. If the pressure continues to rise, the pressure control valve shall operate and the rupture plate shall be ruptured sequentially and the tail gas shall be discharged to the vent stack through the emergency line. As an emergency emission system, even if some untreated substances in the tail gas are released into the atmosphere, they are lighter than air, so it is safe to discharge them to a safe place through the Vent Stack. If the gas pressure is rising or worse, it is discharged from the Vent Stackine, and discharging fuel.

본 연구는 중요한 탄소흡수원의 역할을 하는 산림생태계 탄소흡수 잠재력을 분석하고 이를 통해 탄소 공간지도 제작을 목표로 한다. 연구지역은 대한민국 전역으로, 시도 및 시군구의 공간 단위로 분석을 진행하였으며. 첫째, 침엽수림(Conifers), 활엽수림(Non-Conifers), 혼효림(Mixed), 상록활엽수림(Evergreen broadleaf forests), 죽림(Bamboo)의 면적을 지역별로 산정한 후, 이들 면적에 대한 연간 이산화탄소흡수량 고유계수를 적용하여 지역별 이산화탄소흡수량과 전국 단위의 흡수량을 계산하였다. 분석결과, 전체 산림지의 이산화탄소흡수량은 2010년 56,352,485t CO2/yr, 2015년 55,391,298t CO2/yr, 2020년 52,633,417t CO2/yr로 감소하는 것으로 나타났다. 산림면적의 감소가 주요 감소 원인으로 분석되었고, 부분적으로 기후변화 등에 따른 식생의 종조성 변화도 원인으로 나타났다. 이에 더하여, 상록활엽수림 및 죽림의 면적을 기반으로 탄소흡수량을 분석한 결과 상록활엽수는 55,928t CO2/yr, 죽림은 591,183.4t CO2/yr의 이산화탄소흡수량을 얻을 수 있었다. 지자체별 탄소흡수량 분석결과에서는 태백산맥, 소백산맥을 포함하고 있는 시군구가 다른 지역에 비해 산림지역의 이산화탄소흡수량이 많다는 것을 파악되었고, 대구광역시, 광주광역시, 대전광역시 등 대도시 인접 지역은 상대적으로 이산화탄소흡수량이 적음을 확인할 수 있었다. 결론적으로, 우리나라 탄소중립 실현을 위한 탄소흡수원으로써 산림지의 관리에 있어서 산정체계의 고도화가 필요하다. 특히 기후변화에 따라 변화될 식생대의 분포와 식생별 수목의 종조성 변화를 고려한 임목별 연령별 흡수계수 산정 자료 구축이 필요하다. 본 연구에서 제시한 상록활엽수와 죽림의 경우가 중요한 예시가 될 것이다. 또한, 탄소흡수량 감소에 가장 중요한 요인이 산림면적 감소인 것을 고려할 때, 산림지 면적의 회복을 위한 적극적인 복원 정책의 수립과 이행이 요구되며, 죽림 등 탄소흡수량이 높은 식생의 보전, 확대를 위한 지속 가능한 관리 정책 마련이 필요하다. 특히, 산림면적의 회복을 위하여 지자체 단위에서 면적 기반 산림관리와 지역 단위에서 유역기반의 통합된 산림관리 정책과 이행 방안 마련이 시급하다.

본 연구는 유럽연합(EU)의 환경문제와 섬유패션산업 현황을 바탕으로 스페인의 탄소배출 절감 노력과 인디텍스 그룹의 전략을 분석하였다. 특 히 인디텍스 그룹의 사례를 통해 섬유패션산업의 탄소배출 절감 전략의 효과성을 검토하며, 섬유패션산업이 어떻게 지속 가능한 방향으로 전환 될 수 있는지의 시사점을 제시하고자 한다. 특히 석유산업에 이어 두 번 째로 큰 환경 파괴원인으로 지목되는 패스트 패션의 탄소배출 문제를 조 명한다. 연간 전 세계에서 섬유패션산업은 탄소 배출량의 약 10%를 차 지하며, 이 수치는 모든 국제선 및 해상 운송의 배출량을 합친 것보다도 더 크다. 특히 패스트 패션의 생산과 유통 과정에서 발생하는 탄소배출 은 그 크기가 막대하여 지속가능성에 큰 위협을 미치고 있다. 즉, 패스트 패션의 탄소배출 문제를 해결하기 위한 전략적 접근 방식을 제시하며, 섬유패션산업의 지속가능성 향상을 위한 핵심 요소를 도출하고자 한다.

최근 전 세계적으로 전례 없는 홍수와 극심한 폭염이 발생하면서 급속한 기후 변화의 심각성에 대한 세계적 인식이 높아졌다. 태양광 발전시설의 사회적 수용성과 안전성을 적극 홍보하는 한편, 국가 차원에서 정책 결정과 사업 운영을 최적화하기 위해 노력하고 있다. 본 연구는 영남·호남권 12개 주요 시·도의 태양광 발전설비 효율을 지역 에너지자원 지원 시스템과 기상자료를 활용한 DEA(Data Envelopment Analysis)를 활용하여 분석하였다. 첫째, 지역 내 지리적 범위의 차이는 발전효율의 성능적 평가의 차이점이 발생하는 것을 알 수 있었다. 둘째, 경제적 측면과 환경적 측면을 모두 고려한 태양광 발전시설에 대한 최적의 공간정보시스템의 중요성을 강조한다. 국내 신재생에너지 발전시설의 입지적 조건 개선으로 거시적 측면의 운영을 질적으로 보완하여 에너지 정책적 지원 필요성을 시사하며, 에너지 투자사업의 경제성 및 타당성을 제시하고자 한다.

Within the air purification system of a nuclear power plant, specific radioactive isotopes are extracted from gases through adsorption onto activated carbon. To properly dispose of used activated carbon, it is essential to determine the concentration of radioactive nuclides within it. This study discusses the application of the pyrolysis method for analyzing the concentrations of 3H and 14C in spent activated carbon. The pyrolysis was conducted using Raddec’s Pyrolyser, with adjustments made to parameters such as temperature profiles, airflow rates, sample quantities, and trapping solution volumes. The evaluation method for the pyrolysis of activated carbon to analyze 3H and 14C involved adding 3H and 14C sources to the activated carbon before use and subsequently assessing the recovery rates of the added sources in comparison to the analysis results.

In NPP (nuclear power plant), boric acid is used as a neutron absorbent. So radioactive boric acid waste are generated from various waste streams such as discharge or leakage of reactor coolant water, floor drains, drainage of equipment for operation or maintenance, reactor letdown flows and etc. Depending on KHNP, 20,015 drum (200 L drum) of concentrated boric acid waste were stored in KOREA NPP until 2019. In previous study, our group suggested the waste upcycling process synthesizing B4C neutron absorber using boric acid waste and activated carbon waste to innovatively reduce radioactive wastes. Radioactive activated carbon waste was utilized in off gas treatment system of NPP to capture nuclide such as I-131, C-14 and H-3. Activated carbon waste is treated as low-level radioactive waste and pre-treatment system for removing nuclide from the activated carbon waste is needed to use B4C up-cycling process. In this study, microwave treatment system is suggested to treat the activated carbon waste. Activated carbon waste was exposed to microwave for a few minutes and temperature of the waste was dramatically increased over 400°C. Nuclide in the activated carbon waste were selectively removed from the waste without massive production of secondary off gas waste.

The primary heat transport system consists mainly of the in-core fuel channels connected to the steam generators by a system of feeder pipes and headers. The feeders and headers are made of carbon steel. Feeders run vertically upwards from the fuel channels across the face of the reactor and horizontally over the refueling machine to the headers. Structural materials of the primary systems of nuclear power plants (NPPs) are exposed to high temperature and pressure conditions, so that the materials employed in these plants have to take into accounts a useful design life of at least 30 years. The corrosion products, mainly iron oxides, are generated from the carbon steel corrosion which is the main constituent of the feeder pipes and headers of this circuit. Typical film thickness on CANDU-PHWR surface is 75μm or 30mg/cm2. Deposits on PHWR tends to be much thicker than PWR due to use of carbon steel and also for the source of corrosion products available on the carbon steel surface. Degradation of carbon steel for the feeder pipes transferring the primary system coolant by flow-assisted corrosion in high temperature has been reported in CANDU reactors including Point Lapreau, Gentully-2, Darlington and Bruce NPPs. The formation of Fe3O4 film on a carbon steel surface reduces the dissolution rate of steel substantially. The protectiveness of the Fe3O4 film over the carbon steel is affected by the environmental factors and the operational parameters of the feeder pipes, including the velocity, wall shear stress, solution pH, temperature, concentration of dissolved iron, quality of solution, etc. For effective chemical decontamination of these thick oxides containing radionuclides such as Co-60, it is necessary to understand the corrosion behaviors of feeder pipes and the characteristics of oxide formed on it. In this work, we investigated the growth of oxide films that develop on type SA-107 Gr. B carbon steel in high temperature water and steam environment by scanning electron microscopy (SEM) and glow discharge optical emission spectrometry (GD-OES) for the quantification and the solidstate speciation of metal oxide films. This study was especially focused to set the experimental tests conditions how to increase the oxide thickness up to 50 m by changing the oxidation conditions, such as solution chemistry and thermo-hydraulic conditions both temperature and pressure and so on.

Pt/C catalysts were prepared using black carbon (CB), and evaluated for their potential application as a catalyst of liquid-phase catalystic exchange for tritium treatment. CB was treated with 10% H2O2 solution for 0 and 2 hours at 105°C, Ethylene glycol and 40wt% Pt were added to the dried treated sample to prepare a Pt/C catalyst. The physical and chemical properties of the prepared catalysts were evaluated by BET, XRD, elemental analysis (EA), and TEM analyses. As a result of BET analysis, the surface area of CB without 10% H2O2 was 237.2 m2·g-1, and after treatment with 10% H2O2, it decreased to 181.2 m2·g-1 for 2 hours. However, the internal surface area increased, indicating the possibility that more Pt could be distributed inside the CB treated with 10% H2O2. In the XRD analysis results, the presence of Pt was confirmed by observing the Pt peak in the prepared Pt/C catalyst, and it was also observed through TEM analysis that Pt was evenly distributed within the CB. The elemental analysis (EA) results showed that the ratio of S and N decreased and the ratio of O increased with increasing 10% H2O2 treatment time. The H2O2 treated carbon supported Pt catalysts and polytetrafluoroethylene were then loaded together on a foamed nickel carrier to obtain hydrophobic catalysts. Our hydrophobic Pt catalyst using H2O2 treated black carbon are expected to be usefully used in the tritium treatment system.

Activated carbon (AC) is used for filtering organic and radioactive particles, in liquid and ventilation systems, respectively. Spent ACs (SACs) are stored till decaying to clearance level before disposal, but some SACs are found to contain C-14, a radioactive isotopes 5,730 years halflife, at a concentration greater than clearance level concentration, 1 Bq/g. However, without waste acceptance criteria (WAC) regarding SACs, SACs are not delivered for disposal at current situation. Therefore, this paper aims to perform a preliminary disposal safety examination to provide fundamental data to establish WAC regarding SACs SACs are inorganic ash composed mostly of carbon (~88%) with few other elements (S, H, O, etc.). Some of these SACs produced from NPPs are found to contain C-14 at concentration up to very-low level waste (VLLW) criteria, and few up to low-level waste (LLW) criteria. As SACs are in form of bead or pellets, dispersion may become a concern, thus requiring conditioning to be indispersible, and considering VLL soils can be disposed by packaging into soft-bags, VLL SACs can also be disposed in the same way, provided SACs are dried to meet free water requirement. But, further analysis is required to evaluate radioactive inventory before disposal. Disposability of SACs is examined based on domestic WAC’s requirement on physical and chemical characteristics. Firstly, particulate regulation would be satisfied, as commonly used ACs in filters are in size greater than 0.3 mm, which is greater than regulated particle size of 0.2 mm and below. Secondly, chelating content regulation would be satisfied, as SACs do not contain chelating chemicals. Also, cellulose, which is known to produce chelating agent (ISA), would be degraded and removed as ACs are produced by pyrolysis at 1,000°C, while thermal degradation of cellulose occurs around 350~600°C. Thirdly, ignitability regulation would be satisfied because as per 40 CFR 261.21, ignitable material is defined with ignition point below 60°C, but SACs has ignition point above 350°C. Lastly, gas generation regulation would be satisfied, as SACs being inorganic, they would be targeted for biological degradation, which is one of the main mechanism of gas generation. Therefore, SACs would be suitable to be disposed at domestic repositories, provided they are securely packaged. Further analysis would be required before disposal to determine detailed radioactive inventories and chemical contents, which also would be used to produce fundamental data to establish WAC.

Activated carbon (AC), extensively used across various industrial sectors, serves as a sponge for different types of gases due to its porous carbon material. These gases are attracted to the carbon substrate via van der Waals forces. In nuclear power plants, AC is commonly used to adsorb radioactive gases such as 86Kr and 134Xe, as well as radioiodine sources like 131I and 133I from gaseous effluents. Even if the adsorbed radioactive gases and radioiodine decay into non-radioactive elements, the spent AC still contains radioactive species with long half-lives, such as 3H (Tritium, T) and 14C (radiocarbon). Minimizing and separating waste that contains long-lived nuclides (e.g., 14C) are pivotal components of an efficient waste management approach. A challenging aspect of effectively managing disposed AC is to minimize long-lived radioactive substances by eliminating them. This paper explores and summarizes the technology used to remove pollutants (3H, 14C) trapped within the pores of Activated carbon through thermochemical vacuum and surface oxidation processes. By recycling and reusing spent Activated carbon, we anticipate a reduction in the volume of radioactive waste, leading to decreased disposal costs. Furthermore, this paper will contribute as a valuable reference in future studies, enhancing the understanding of vacuum thermal desorption and surface oxidation of used Activated carbon.