• 제목/요약/키워드: Delayed potential

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UK Civil Nuclear Decommissioning, a Blueprint for Korea's Nuclear Decommissioning Future?: Part I - Nuclear Legacy, Strategies, and the NDA

  • Foster, Richard I.;Park, June Kyung;Lee, Keunyoung;Seo, Bum-Kyoung
    • 방사성폐기물학회지
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    • 제19권3호
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    • pp.387-419
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    • 2021
  • The challenges facing companies and institutions surrounding civil nuclear decommissioning are diverse and many, none more so than those faced in the United Kingdom. The UK's Generation I nuclear power plants and early research facilities have left a 'Nuclear Legacy' which is in urgent need of management and clean-up. Sellafield is quite possibly the most ill-famed nuclear site in the UK. This complex and challenging site houses much of what is left from the early days of nuclear research in the UK, including early nuclear reactors (Windscale Piles, Calder Hall, and the Windscale Advanced Gas Cooled Reactor) and the UK's early nuclear weapons programme. Such a legacy now requires careful management and planning to safely deal with it. This task falls on the shoulders of the Nuclear Decommissioning Authority (NDA). Through a mix of prompt and delayed decommissioning strategies, key developments in R&D, and the implementation of site licenced companies to enact decommissioning activities, the NDA aims to safety, and in a timely manner, deal with the UK's nuclear legacy. Such approaches have the potential to influence and shape other such approaches to nuclear decommissioning activities globally, including in Korea.

그린수소 기반 섹터 커플링 통한 재생에너지 출력제한 경감효과 연구 (Study on Reduction of Curtailment of Renewable Generation based on Green Hydrogen Sector Coupling)

  • 전우영;김진이;이성우
    • 신재생에너지
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    • 제18권2호
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    • pp.50-59
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    • 2022
  • The Korean government announced the "1st Basic Plan for the Transition to Hydrogen Economy" in 2021 and declared the establishment of a hydrogen industry ecosystem by 2040. To build a low-carbon power system, resources that can efficiently accommodate renewable energy are required, and green hydrogen is considered a potential solution. This study analyzed the economic feasibility of green hydrogen-based sector coupling to reduce curtailment of renewable generation in the Jeju power system by 2025 under the scenario of with or without HVDC#3. The result showed that HVDC#3 significantly reduced the frequency of curtailment from 16.1% to 3.0%. In addition, green hydrogen-based sector coupling was an economically feasible option as result showed an IRR of 4.86% when HVDC#3 was connected and 11.45% when it was not under the condition of achieving 50% curtailment reduction. This study shows that the higher the level of renewable energy deployment, the more delayed the HVDC connection between Jeju and the main land, and the lower the SMP, the more economically feasible the green hydrogen-based sector coupling is. Furthermore, this study suggests that the policy goal of completely reducing curtailment is not economically efficient.

Performance evaluation of Accident Tolerant Fuel under station blackout accident in PWR nuclear power plant by improved ISAA code

  • Zhang, Bin;Gao, Pengcheng;Xu, Tao;Gui, Miao;Shan, Jianqiang
    • Nuclear Engineering and Technology
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    • 제54권7호
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    • pp.2475-2490
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    • 2022
  • The Accident Tolerant Fuel (ATF) is a new concept of fuel, which can not only withstand the consequences of the accident for a longer time, but also maintain or improve the performance under operating conditions. ISAA is a self-developed severe accident analysis code, which uses modular structures to simulate the development processes of severe accidents in nuclear plants. The basic version of ISAA is developed based on UO2-Zr fuel. To study the potential safety gain of ATF cladding, an improved version of ISAA, referred to as ISAA-ATF, is introduced to analyze the station blackout accident of PWR using ATF cladding. The results show that ATF cladding enable the core to maintain a longer time compared to zirconium alloy cladding, thereby enhancing the accident mitigation capability. Meanwhile, the generation of hydrogen is significantly reduced and delayed, which proves that ATF can improve the safety characteristics of the nuclear reactor.

UK Civil Nuclear Decommissioning, a Blueprint for Korea's Nuclear Decommissioning Future?: Part II - UK's Progress and Implications for Korea

  • Foster, Richard I.;Park, June Kyung;Lee, Keunyoung;Seo, Bum-Kyoung
    • 방사성폐기물학회지
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    • 제20권1호
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    • pp.65-98
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    • 2022
  • The nuclear legacy that remains in the United Kingdom (UK) is complex and diverse. Consisting of legacy ponds and silos, redundant reprocessing plants, research facilities, and non-standard or one-off reactor designs, the clean-up of this legacy is under the stewardship of the Nuclear Decommissioning Authority (NDA). Through a mix of prompt and delayed decommissioning strategies, the NDA has made great strides in dealing with the UK's nuclear legacy. Fuel debris and sludge removal from the legacy ponds and silos situated at Sellafield, as part of a prompt decommissioning strategy for the site, has enabled intolerable risks to be brought under control. Reactor defueling and waste retrievals across the Magnox fleet is enabling their transition to a period of care and maintenance; accelerated through the adopted 'Lead and Learn' approach. Bespoke decommissioning methods implemented by the NDA have also enabled the relevant site licence companies to tackle non-standard reactor designs and one-off wastes. Such approaches have potential to influence and shape nuclear decommissioning decision making activities globally, including in Korea.

Delayed Diagnosis of a Tibial Stress Fracture Associated with Glucocorticoid and Methotrexate Therapy in a Patient with Rheumatoid Arthritis: A Case Report

  • Shin, Hye Jeong;Lim, Yi Gun;Lee, Gi Hyang;Lee, Hyun Seok;Song, Beom Yong;Choi, Yoo Min
    • Journal of Acupuncture Research
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    • 제39권1호
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    • pp.64-69
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    • 2022
  • The risk of stress fractures is associated with rheumatoid arthritis (RA), which can aggravate bone loss. We report the case of a patient who was on long-term medication for RA presenting with lower extremity pain on the left and swelling without trauma. Magnetic resonance imaging and plain radiographs at the previous hospital showed no signs of fracture, but radiographs performed later, revealed a stress fracture of the left distal tibia. The stress fracture may have occurred due to multiple reasons such as long-term use of methotrexate and glucocorticoids, active RA, postmenopausal state, and immobility. Suspicion of a stress fracture should not be ruled out especially in RA patients with persistent pain, even if the radiographical findings are normal. Additional imaging and follow-ups are essential. The patient's pain was relieved with Korean medicine treatments, which suggests their potential application for stress fractures in RA patients.

Well-Differentiated Squamous Cell Carcinoma Found on the Tail of a Captive Leopard (Panthera Pardus): The Importance of Diagnostic Tests

  • Kim, Sungryong;Hong, Sunghyun S.;Kim, Jeong-Ho;Na, Ki-Jeong
    • 한국임상수의학회지
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    • 제39권2호
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    • pp.70-74
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    • 2022
  • A 14-year-old intact male captive leopard (Panthera pardus) first presented with a focal alopecic lesion on the dorsal aspect of the distal one-third of its tail. Although itraconazole was administered, the lesion progressed deeper and became ulcerated due to self-trauma. Due to the wild nature of the leopard, daily dressing of the wound and replacing the bandages without anesthesia became too dangerous, and amputation became necessary. A postoperative tissue sample was submitted for histopathological examination, and tramadol, amoxicillin/clavulanate, and gabapentin were administered. In the days following the amputation, the leopard's appetite significantly decreased, and the patient passed away 18 days later. Histopathological examination of the specimen revealed well-differentiated squamous cell carcinoma (SCC). In hindsight, had more cells been collected by a fine-needle aspirate (FNA) biopsy or had additional FNA biopsies been performed, SCC might have been diagnosed based on its cytological features rather than delayed histopathological findings. The current study highlights the critical reasons why clinicians may often misdiagnose SCC and the importance of being more aware of potential tumors in ulcerative lesions, which are often incorrectly treated as infectious skin diseases. This is also the first report of cutaneous SCC in a leopard.

RNN-based integrated system for real-time sensor fault detection and fault-informed accident diagnosis in nuclear power plant accidents

  • Jeonghun Choi;Seung Jun Lee
    • Nuclear Engineering and Technology
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    • 제55권3호
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    • pp.814-826
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    • 2023
  • Sensor faults in nuclear power plant instrumentation have the potential to spread negative effects from wrong signals that can cause an accident misdiagnosis by plant operators. To detect sensor faults and make accurate accident diagnoses, prior studies have developed a supervised learning-based sensor fault detection model and an accident diagnosis model with faulty sensor isolation. Even though the developed neural network models demonstrated satisfactory performance, their diagnosis performance should be reevaluated considering real-time connection. When operating in real-time, the diagnosis model is expected to indiscriminately accept fault data before receiving delayed fault information transferred from the previous fault detection model. The uncertainty of neural networks can also have a significant impact following the sensor fault features. In the present work, a pilot study was conducted to connect two models and observe actual outcomes from a real-time application with an integrated system. While the initial results showed an overall successful diagnosis, some issues were observed. To recover the diagnosis performance degradations, additive logics were applied to minimize the diagnosis failures that were not observed in the previous validations of the separate models. The results of a case study were then analyzed in terms of the real-time diagnosis outputs that plant operators would actually face in an emergency situation.

Be it unresolved: Measuring time delays from unresolved light curves

  • Bag, Satadru;Kim, Alex G.;Linder, Eric V.;Shafieloo, Arman
    • 천문학회보
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    • 제46권1호
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    • pp.47.4-48
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    • 2021
  • Gravitationally lensed Type Ia supernovae may be the next frontier in cosmic probes, able to deliver independent constraints on dark energy, spatial curvature, and the Hubble constant. Measurements of time delays between the multiple images become more incisive due to the standardized candle nature of the source, monitoring for months rather than years, and partial immunity to microlensing. While currently extremely rare, hundreds of such systems should be detected by upcoming time-domain surveys. Others will have the images spatially unresolved, with the observed lightcurve a superposition of time delayed image fluxes. We investigate whether unresolved images can be recognized as lensed sources given only lightcurve information and whether time delays can be extracted robustly. We develop a method that we show can identify these systems for the case of lensed Type Ia supernovae with two images and time delays exceeding ten days. When tested on such an ensemble the method achieves a false positive rate of ≲5%, and measures the time delays with the completeness of ≳93% and with a bias of ≲0.5% for time delay ≳10 days. Since the method does not assume a template of any particular type of SN, the method has the potential to work on other types of lensed SNe systems and possibly on other transients.

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The investment point on cooperative innovation in EVs for the spoke-smart cities : focused on Nordic countries and Korea

  • Seo, Dae-Sung
    • 융합경영연구
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    • 제5권3호
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    • pp.1-11
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    • 2017
  • E-infrastructural economy for ICT Living-Labs is a need for economic and cultural changes in various types of cars in accordance with the supply of the electric car. Depending on the number of cases by analyzing the supply and demand of electric vehicles among Korea and Northern Europe countries. it was indirectly proved that it makes economic growth. The research design is analyzed with the data and how to respond quickly to focus on the possibility of potential changes to the infrastructure realization and commercialization of government enterprises or electric cars through the ICT Living-Labs in Nordic countries. The data indicates that the leading commercialization emphasize on the development of the electric economic convergence and scalability for electric vehicle. When It shows the time of the infrastructure as ICT Living-Labs being delayed, it lowered growth target results for the development of the electric car industry in the future. All this is from the reason of opening the E-convergence economy over time. It is required that Korea should prepare E-convergence economy. Public regional energy should be present through the consistent selection of development for energy linking E-economy and E-trans distribution. Korea needs to be many difficulties in building the E- infrastructure for ICT Living-Labs. Unlike the Northern Europe it is to prepare the active support of both government and business. The role of the government discovers that the power generation through the quick selection of the industry, as well as to connect with the growth of the smart cities with the EVs industry.

Clinical Experience of Surgical Treatment for Penetrating Pulmonary Gunshot Wound of a Civilian in Korea: A Case Report

  • Seonyeong Heo;Jung Hee Kim;Younggi Jung;Kwanghyoung Lee;Sungho Lee;Eunjue Yi
    • Journal of Chest Surgery
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    • 제57권1호
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    • pp.87-91
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    • 2024
  • Gunshot-induced chest trauma is exceedingly rare among civilians in South Korea due to strong firearm control policies. In contrast to military reports emphasizing the use of emergent open thoracotomy to increase chances of survival, most penetrating non-cardiac injuries in civilian settings are managed conservatively, such as through chest tube insertion, as they typically result from lower-energy bullets. However, early surgical intervention for penetrating gunshot wounds can help reduce delayed fatalities caused by septic complications from pneumonia or empyema. The advent of minimally invasive thoracic surgery has provided cost-effective and relatively non-invasive treatment options, aided in the prevention of potential complications from undrained hematomas, and facilitated functional recovery and reintegration into society. We successfully treated a patient with a penetrating gunshot wound to the chest using video-assisted thoracoscopic surgery.