Regulatory agencies require burn-up verification to ensure that dry storage casks using burn-up credit are not loaded with fuel with a reactivity greater than the allowable standard. Accordingly, in preparation for dry storage of SF, the reliability of the burnup was verified and action plans for fuel with confirmed errors were reviewed. Reliability verification was performed by comparing the actual burnup calculated with combustion calculation code (TOTE, ISOTIN) used in NPP and the design burnup calculated with the nuclear design code (ANC). As a result of comparing the differences between actual burnup and design burnup for 7,414 assemblies of SF generated from CE-type NPPs, the average deviation was confirmed to be 0.79% and 220 MWD/MTU. In the CE-type NPPs, no fuel showing large deviations was identified, and it was confirmed that reliability was secured. As a result of comparing the differences in 11,082 assemblies of SF generated from WH-type NPPs, the differences were not large, averaging 1.16% or 422 MWD/MTU. However, fuels showing significant differences were identified, and cause analysis was performed for those fuels. The cause analysis used a method of comparing the burnup of symmetrically loaded fuels in the reactor. For fuels that were not symmetrically loaded, a method was used to compare them with fuels with similar combustion histories. As a result of the review, it was confirmed that the fuel was under- or over-burned compared to symmetrically loaded fuel. For fuels for which clear errors have been identified, we are considering replacing them with the design burnup, and for fuels whose causes cannot be confirmed, we are considering ways to maintain the actual burnup.

In Korea, most temporary storage facilities for spent nuclear fuel are nearing saturation. As an alternative to this, the 2nd basic plan for high-level radioactive waste management specified the operation plan of dry interim storage facility. Meanwhile, the NSSC No. 2021-19 stipulates that it is necessary to evaluate the possibility and potential effect of accident before operating interim storage facility. Therefore, this study analyzed the categories of accident scenarios that may occur in dry storage facility as part of prior research on this. We investigated the case of categorization of dry storage facility accident scenarios of IAEA, NRC, KAREI, and KINS. The IAEA presented accident scenarios that could occur in on-site dry storage facility operated with silo and cask method. NRC has classified accident scenarios in dry storage facility and estimated the probability of accidents for each. KAERI and KINS selected major accident scenarios and analyzed the processes for each, in preparation for the introduction of dry storage facility in Korea in the future. Overall, a total of 10 accident scenarios were considered, and the scenarios considered by each institution were different. Among 10 scenarios, cask drop and aircraft collision were included in the categorization of most institutions. The results of this study can be used as basic data for cataloging accidents subject to safety evaluation when introducing dry interim storage facility in Korea in the future.

A lot of CANDU Spent Fuels (CSFs) have been stored in spent nuclear fuel pools and dry storage facilities. In accordance with the enhanced nuclear regulations, the initial characteristics of CSF should be inspected to ensure the integrity of CSF and the reliable operation of storage system before loading it into a cask for long-term dry storage. For the inspections, an initial characteristics measurement equipment was designed, which is used for Pool-Side Examination (PSE) in the spent fuel pool of the pressurized heavy water reactor nuclear power plant. Measurements using the equipment consist of non-contact inspections and contact inspections. The non-contact inspections do not affect CSF integrity, whereas the integrity of CSF can be reduced during the contact inspections under abnormal operating conditions because the probe of equipment may apply specific loads to the CSF. Therefore, the structural integrity evaluations of equipment and CSF are performed using Finite Element (FE) analyses for four combinations based on two abnormal conditions and two probe positions. The used abnormal conditions are the pressing load condition and the scratching load condition, and two probe positions are the center and bottom of the fuel rod in the longitudinal direction, respectively. In this evaluation, the bottoms of the fuel rod or CSF are defined as the regions facing the bottom surface of equipment. The analysis of the pressing load condition is performed by pressing the probe of the equipment in radial direction of the CSF fuel rod. That of the scratching load condition is carried out by applying a specific radial load to the CSF fuel rod using the probe and then applying the load to the surface of the fuel rod while moving axially along the surface. All combinations are analyzed considering geometric, boundary and material non-linearity under the dynamic load, which is dependent on the equipment operating velocity. The stresses of CSF and equipment components were obtained from these analyses. The maximum stress of each component was generated at the combination on the scratching load condition for the bottom position among the four combinations. The obtained maximum stresses are lower than the yield stress for each component material. Also, the CSF is not overturned due to the support plate of the equipment in all analyses. Therefore, the structural integrity and safety of the equipment and the CSF are maintained under abnormal operating conditions during the inspection using the initial characteristic measurement equipment.

Zircaloy-4 is utillzed in nuclear fuel rod cladding due to its strength and corrosion resistance. However, it can undergo deformation over time, known as creep, which poses a safety risk in reactors. Furthermore, hydrogen absorption during reactor operation can alter its properties and affect creep rates. Previous research suggests a trend in which hydrogen concentration corelates unidirectionally with creep rates, either increasing or decreasing as the concentration rises. This trend can also be observed in EPRI’s creep model, EDF-CEA Model-3. However, recent literature has suggested that creep behavior may vary depending on the state of hydrogen presence. Therefore, it has become evident that creep behavior can be influenced not only by hydrogen concentration but also by the state of hydrogen presence, whether it is in a solid solution state or precipitated as hydrides. Our study aimed to compare creep behavior in specimens with hydrogen concentrations below and above solubility limits. We fabricated Zircaloy-4 plate specimens with varying hydrogen concentrations and conducted creep tests. The results revealed that specimens below the solubility limit exhibited decreasing creep rates as hydrogen concentration increased, while those above the limit displayed increasing creep rates. This investigation confirms that the state of hydrogen presence significantly impacts creep behavior within Zircaloy-4 cladding. As part of our additional research plans, we intend to conduct creep tests on the material based on its orientation, whether it is in the rolling direction (RD) or the transverse direction (TD). We also plan to perform creep tests on ring specimens. Additionally, for the ring specimens, we aim to evaluate how creep behavior differs between the cold-worked stress-relieved (CWSR) condition and the recrystallized annealed (RXA) condition achieved through high-temperature heat treatment.

The types of fuel loaded and burned in domestic nuclear power plants are WH-type and OPR/ APR-type nuclear power plants, with a total of 19 types. In the case of spent nuclear fuel released in Korea, the low combustion level of 45,000 MWD/MTU or less accounts for about 75%. In terms of fuel type, WH 17×17 and CE 16×16 fuels account for about 85% of all spent nuclear fuels. The thickness of the oxide film of the fuel cladding can make the fuel rod vulnerable during reactor operation, directly affecting the integrity of the fuel rods. so, it is a very important design factor in design. Therefore, the fuel rod design code that predicts and evaluates this has also been developed to accurately predict fuel rod corrosion. And it’s being applied to the design. In this study, the ECT probe measured by inserting it between fuel rods. The thickness of the fuel cladding oxide film was measured for spent nuclear fuel. When reloading operational nuclear fuel, the IAEA recommends an oxide film thickness of up to 100 micrometers. In this study, it was confirmed that spent nuclear fuels keeping integrity burned for 2-3 cycles were sufficiently maintained within the limit. However, the difference could be confirmed according to the characteristics of the coating material, the combustion cycle, and the use of poison rods. For the reliability of the data, symmetrical to the quadrant fuels were selected, and the fuel burned at the same period was measured. The method of selecting the target fuel can produce meaningful results.

Recently, the status of North Korea’s denuclearization has become an international issue, and there are also indications of potential nuclear proliferation among neighboring countries. So, the need for establishment of nuclear activity verification technology and strategy is growing. In terms of ensuring verification completeness, sample collection-based analysis is essential. The concepts of Chain of Custody (CoC) and Continuity of Knowledge (CoK) can be defined in the process of sample extraction as follows: CoC is interpreted as the ‘system for managing the flow of information subjected by the examinee’, and CoK is interpreted as the ‘Continuity of information collection through CoC subjected by the inspector’. In the case of sample collection process in unreported areas for nuclear activity verification, there are additional risks such as worker exposure/kidnapping or sample theft/tampering. Therefore, the introduction of additional devices might be required to maintain CoC and CoK in the unreported area. In this study, an Environmental Geometrical Data Transfer (EGDT) was developed to ensure the safety of workers and the CoC/CoK of the samples during the collection process. This device was designed for achieving both mobility and rechargeability. It is categorized into two modes based on its intended users: sample mode and worker mode. Through the sensors, which is positioned in the rear part of device, such as radiation, gyroscope, light, temperature, humidity and proximity sensors, it can be easily achievable various environmental information in real-time. Additionally, GPS information can also be received, allowing for responsiveness to various hazardous scenarios. Moreover, the OLED display positioned on the front gives us for checking device information such as the current status of the device such as the battery level, the connectivity of wifi, and etc. Finally, an alarm function was integrated to enable rapid awareness during emergency situations. These functions can be updated and modified through Arduino-based firmware, and both the device and the information collected through it can be remotely controlled via custom software. Based on the presented design conditions, a prototype was developed and field assessments were conducted, yielding results within an acceptable margin of error for various scenarios. Through the application of the EGDT developed in this study to the sample collection process for nuclear activity verification purposes, it is expected to achieve a stable maintenance of CoC/CoK through more accurate information transmission and reception.

Safeguards systems and measures are determined through diversion scenario analysis based on the facility design information submitted to the IAEA when a new nuclear facility is introduced. While the concept of safeguards-by-design (SBD), which considers the safeguards from the design phase for a facility operator to minimize unplanned changes or disruption to facility operations as well as for the IAEA to increase the efficiency and effectiveness in safeguards implementation, has been emphasized for more than a decade, there is no practical tool or guidance on how to apply it. In this study, we develop a diversion path analysis tool and introduce how to apply SBD using it. A diversion path analysis tool was developed based on the elements that constitute diversion and the algorithm generated based on the initial information of facility and nuclear material flow. The results of utilizing the analysis tool depending on a different level of facility information and the safeguards set-ups were compared through examples. Taking a typical light water reactor as an example, the test analyzed the automatic generation of dedicated routes, configuration of safeguards measures, and diversion path analysis. Through this, the application and limitations of the analysis tool are discussed, and ideas for utilization according to the SBD concept and necessary regulatory guidance are proposed. The results of this study are expected to be directly utilized to domestic nuclear control during the regulation process for a construction of new nuclear power systems, and furthermore, to enhance national credibility in the engagement with the IAEA for implementation of safeguards.

Emerging technologies are innovative technologies currently under development or in the early stages of introduction. These technologies have the potential to impact a wide range of industries and sectors significantly and may, therefore, be subject to export controls. The list of emerging technologies subject to export controls varies from country to country and constantly changes as new technologies are developed. For example, the U.S., EU, and South Korea have responded to these changes by adding software and technologies related to artificial intelligence and machine learning to their export control lists. Nevertheless, export control of emerging technologies still presents challenges and limitations. The rapid pace of technological advancement makes it difficult for export control regulations to keep up. For export control purposes, international cooperation on information sharing and control methods is necessary for most countries to control similar items. Several new technologies in the nuclear field may be subject to export controls. These technologies include advanced reactors, nuclear fuel cycle technologies, and nuclear waste management technologies. Small modular reactors (SMRs) and fourth-generation reactors are being developed as advanced technologies, and new technologies are being developed to improve the nuclear fuel cycle. There is also active development of technologies for space applications utilizing nuclear reactors, such as the Nuclear Thermal Propulsion System and the Nuclear Electric Propulsion System. As these technologies may include new systems and items not in existing export control, they may pose a proliferation risk or may include software design know-how for advanced materials, it is necessary to consider whether and how they should be subject to export control to prevent nuclear proliferation. Overall, export controls are an essential issue in the emerging technology and nuclear energy sectors. Countries are moving toward strengthening regulations and international cooperation to overcome these challenges and ensure safe technology transfer, and South Korea should actively participate and lead this trend.

In recent times, drone technology has been rapidly advancing and becoming increasingly popular. Furthermore, there has been an increase in the number of crimes and terrorism cases targeting national facilities using drones. This study aims to categorize the types of drone threats that could pose future risks to nuclear power plants. For this study, we are investigating domestic and foreign drone terrorism cases and identifying the specifications of drones used. It has been confirmed that products from Chinese DJI companies have frequently appeared as commercial drones used in terrorism. This suggests that conversion of general commercial drones into weapons can be effectively utilized for terrorist activities. There is an elevated risk of terrorism involving multiple small drones. Nuclear power plants must also devise protective measures against a large influx of drones. Additionally, it is predicted that North Korea is developing drones equipped with return technology through GPS-based autonomous mission flights. North Korea’s drones are presumed to have been converted from Chinese drones (SKY-09P, UV10CAM, etc.). According to the analysis based on the weight and size of the drone, drones weighting less than 150 kg and wingspan of less than 3 m are used for terrorism. To effectively detect drones, it is necessary to implement measures such as integrating and deploying various equipment to compensate for equipment limitations (radio waves, radar, video, sound, etc.). In the case of long-distance flight, a number of fixed-wing drones capable of autonomous mission flight and long-distance flight were used. North Korea’s drones use GPS-based autonomous mission flights, so it is necessary to prepare drones that do not transmit RF signals to detect them. Both RF signal detection and GPS jamming should be carried out, with GPS jamming taking precedence, even in the case of fixedwing drones. The results of this study could contribute to enhancing the level of physical protection of nuclear power plants.

We produced an activated carbon using sodium-lignosulfonate, in which we investigated how the sodium salt in lignin served as the activating agent during heat treatment. Our process resulted in a product with a high specific surface area of 1324 m2/ g at 800 °C and microporous structure. During the activation process, we observed the consumption of carbon due to the dehydration reaction of NaOH and the reduction of Na2CO3 to metallic Na, which created pores through oxidation/ reduction reactions. The intercalation of metallic Na between the lattices at high temperatures formed additional pores and increased the specific surface area. Our proposed mechanism holds promise for enhancing the control of the microstructure and porosity of activated carbons through the thermal treatment of biomass.

The development of food packaging materials with mechanical and antimicrobial properties is still a major challenge. N, P-doped carbons (NPCs) were synthesized. Poly(butylene adipate-co-terephthalate) (PBAT), which has an adverse effect on the environment and affects petroleum resources, has been commonly used for applications as food packaging. The development of PBAT composites reinforced with NPCs and studies on their structure and antimicrobial properties are presented in this study. The composite materials in the PBAT/NPCs were processed by solution casting. The plasticizing properties of NPCs enhanced the mechanical strength of composites produced of PBAT and NPCs. The thermal properties of PBAT composites were enhanced with addition of NPCs, according to thermogravimetric analysis (TGA). After reinforcement, PBAT/NPCs composites became more hydrophobic, according to contact angle measurements. In studies against S. aureus and E. coli food-borne pathogenic bacteria, the obtained composites show noticeably improved antimicrobial activity. The composite materials, according to the results of PBAT and NPCs may be a good choice for packing for food that prevents microorganisms.

Cholesterol is prone to oxidation, which results in the formation of cholesterol oxidation products (COPs). This occurs because it is a monounsaturated lipid with a double bond on C-5 position. Cholesterol in foods is mostly non-enzymatically oxidized by reactive oxygen species (ROS)-mediated auto-oxidative reaction. The COPs are found in many common foods of animal-origin and are formed during their manufacture process. The formation of COPs is mainly related to the temperature and the heating time the food is processed, storage condition, light exposure and level of activator present such as free radical. The level of COPs in processed foods could reach up to 1-10 % of the total cholesterol depending on the foods. The most predominant COPs in foods including meat, eggs, dairy products as well as other foods of animal origin were 7-ketocholesterol, 7 α-hydroxycholesterol (7α-OH), 7β-hydroxycholesterol (7β-OH), 5,6α-epoxycholesterol (5,6α -EP), 5,6β-epoxycholesterol (5,6β-EP), 25-hydoxycholesterol (25-OH), 20-hydroxycholesterol (20-OH) and cholestanetriol (triol). They are mainly formed non-enzymatically by cholesterol autoxidation. The COPs are known to be potentially more hazardous to human health than pure cholesterol. The procedure to block cholesterol oxidation in foods should be similar to that of lipid oxidation inhibition since both cholesterol and lipid oxidation go through the same free radical mechanism. The formation of COPs in foods can be stopped by decreasing heating time and temperature, controlling storage condition as well as adding antioxidants into food products. This review aims to present, discuss and respond to articles and studies published on the topics of the formation and inhibition of COPs in foods and key factors that might affect cholesterol oxidation. This review may be used as a basic guide to control the formation of COPs in the food industry.

증산은 적정 관수 관리에 중요한 역할을 하므로 수분 스트레스에 취약한 토마토와 같은 작물의 관개 수요에 대한 지식이 필요하다. 관수량을 결정하는 한 가지 방법은 증산량을 측정하는 것인데, 이는 환경이나 생육 수준의 영향을 받는다. 본 연구는 분단위 데이터를 통해 수학적 모델과 딥러닝 모델을 활용하여 토마토의 증발량을 추정하 고 적합한 모델을 찾는 것을 목표로 한다. 라이시미터 데이터는 1분 간격으로 배지무게 변화를 측정함으로써 증산 량을 직접 측정했다. 피어슨 상관관계는 관찰된 환경 변수가 작물 증산과 유의미한 상관관계가 있음을 보여주었다. 온실온도와 태양복사는 증산량과 양의 상관관계를 보인 반면, 상대습도는 음의 상관관계를 보였다. 다중 선형 회귀 (MLR), 다항 회귀 모델, 인공 신경망(ANN), Long short-term memory(LSTM), Gated Recurrent Unit(GRU) 모델을 구 축하고 정확도를 비교했다. 모든 모델은 테스트 데이터 세트에서 0.770－0.948 범위의 R2 값과 0.495mm/min－ 1.038mm/min의 RMSE로 증산을 잠재적으로 추정하였다. 딥러닝 모델은 수학적 모델보다 성능이 뛰어났다. GRU 는 0.948의 R2 및 0.495mm/min의 RMSE로 테스트 데이터에서 최고의 성능을 보여주었다. LSTM과 ANN은 R2 값이 각각 0.946과 0.944, RMSE가 각각 0.504m/min과 0.511로 그 뒤를 이었다. GRU 모델은 단기 예측에서 우수한 성능 을 보였고 LSTM은 장기 예측에서 우수한 성능을 보였지만 대규모 데이터 셋을 사용한 추가 검증이 필요하다. FAO56 Penman-Monteith(PM) 방정식과 비교하여 PM은 MLR 및 다항식 모델 2차 및 3차보다 RMSE가 0.598mm/min으로 낮지만 분단위 증산의 변동성을 포착하는 데 있어 모든 모델 중에서 가장 성능이 낮다. 따라서 본 연구 결과는 온실 내 토마토 증산을 단기적으로 추정하기 위해 GRU 및 LSTM 모델을 권장한다.

목적 : 본 연구는 웨스턴 온타리오 어깨 불안정 지수(Western Ontario Shoulder Instability Index: WOSI)를 한국어로 번역하고 측정 속성을 조사하고자 하였다. 연구방법 : 번역은 번역과 역번역 과정을 포함하는 다수의 문헌에서 사용되고 있는 가이드라인에 따라 진행되었다. 연구대 상자는 한국어판 WOSI (K-WOSI)와 Quick Disabilities of the Arm, Shoulder and Hand for Koreans (K-QuickDASH) 검사를 수행하였으며, K-WOSI는 일정한 시간이 지난 후에 같은 대상자에게 반복 측정되었다. 연구자 는 측정결과를 활용하여 내적일치도, 검사·재검사 신뢰도, 동시타당도, 바닥 및 천장 효과를 분석하였다. 결과 : 16명의 환자가 연구에 참여하였으며, 총점 분석 시 내적일치도(Cronbach’s alpha = 0.97)와 검사·재검사 신뢰 도(Pearson’s r = 0.86, Intraclass Correlation Coefficient = 0.92)가 통계학적으로 유의하였다. 평가의 하위 영역 간의 신뢰도 분석 시에도 통계학적으로 유의한 결과가 확인되었다. 또한 K-WOSI와 K-QuickDASH의 상관성이 높았 으며(Pearson’s r = 0.88), K-WOSI의 바닥 및 천장 효과가 발생하지 않았다. 결론 : 본 연구에서 K-WOSI가 어깨가 불안정한 환자들의 삶의 질을 평가하는데 있어 신뢰도와 타당도가 높은 평가로 확 인되었다.

Pseudoscorpiones De Geer, 1778, an order of arachnids, exhibits a global distribution spanning all continents, with the notable exception of Antarctica. This taxon is characterized by a wide array of unique behaviors, including phoresy and matriphagy, setting it apart from other arachnid groups. Moreover, their morphological features distinguish them notably from other animal taxa. Surprisingly, in the context of Korean research, pseudoscorpions remain a relatively unexplored field. Up until the year 2023, only 8 families, 13 genera, and 26 species have been documented in Korea. This number stands in stark contrast to neighboring countries like Japan, boasting 13 families, 35 genera, and an impressive 100 species, and China, which has documented 12 families, 39 genera, and an extensive 168 species of pseudoscorpions.

Erebinae, a subfamily within the family Erebidae, represents one of the largest classification groups in Lepidoptera. This taxonomic group exhibits remarkable ecological diversity and astonishing predator defense adaptations. Erebinae possesses what is presumed to be the most sensitive tympana (hearing organs) among Lepidoptera, allowing them to evade predators such as bats. Furthermore, they have distinctive hindwings, in contrast to their inconspicuous forewings, which they can suddenly expose as a strategy to escape danger from predators. The classification of the subfamily Erebinae is based on molecular studies conducted by Zahiri et al. (2012). However, despite these efforts, there is no single external feature that can reliably identify all Erebinae, and the boundaries of this group remain somewhat unclear. Many specimens have yet to be thoroughly studied, and numerous genera are still awaiting placement within the phylogenetic framework.

대파(Allium fistulosum L.)는 동양에서 옛날부터 중요한 식재료로 재배되어온 중국 원산지의 향신 채소이다. 적어도 통일신라시대부터 재배되어 온 기록이 있으며 현재에도 식재료로 수요가 많아 전국적으로 재배면적이 넓어지고 있고, 종자의 유통량 또한 많다. 대파에는 파굴파리(Liriomyza chinensis), 파좀나방(Acrolepiopsis sapporensis), 파밤나방(Spodoptera exigua) 등이 주요 해충으로 알려져 있다. 전남 진도군은 국내 대파 주산단지로 파밤나방의 발생이 많고 다이아마이드 계통 농약의 저항성이 발현되고 있어 계대사육에 따른 저항성 감소를 실험하고자 한다. 실험은 진도군의 대파밭에서 파밤나방 개체를 채집하여 실내에서 약제처리를 통해 살충률과 섭식률을 검정, 몇세대에 걸쳐 저항성이 감소되는지 알고자 한다.

The superfamily Noctuoidea Latreille, 1809 is the largest group within the order Lepidoptera. This big superfamily have been studied for a long time by numerous authors and literatures. However, these huge number of information make hard to study this important group. In this discussion, we hope to talk a simplified overview of significant literature on Korean noctuid moths, recent trends, and forecast for approaching them more easily.