충주 호암동유적은 금강유역과 남한강유역, 낙동강유역을 연결하는 교통의 요지에 자리하고 있는 데, 적석목관묘는 기원전 2세기 초, 목관묘 2기는 기원전 2세기 전·중엽에 조영된 것으로 추정된다. 과학적 분석 결과, 호암동유적의 청동기들은 구리-주석-납의 3원계 합금으로 추정되며,『주례』고 공기의 금유육제와 비슷한 비율로 주조되었다. 이는 호암동유적의 청동기들이 기능과 용도에 따라 적 합한 성분조성비로 주조되었음을 나타낸다. 납동위원소비 분석을 토대로 한 원료산지추정 결과 중국 북부산 4점, 남한3지구산 10점, 남한2지구산 6점으로 추정되어서 청동원료가 넓은 지역에서 수급되 었음을 보여준다. 충주 호암동유적은 세형동검문화의 중심부인 중서부지역과 원료산지인 남한2지구(강원 동남부-경 북 동북부지역) 사이에 자리해서 무덤 피장자들이 청동원료를 수급하는 데 중요한 역할을 담당했을 것으로 생각된다. 그리고 세형동검문화가 일본열도로 파급되는 시기는 호암동유적의 유이식동모보다 늦은 시기로 추정되므로 발전Ⅰ기 말보다는 발전Ⅱ기 초로 생각된다. 호암동 적석목관묘의 무기류는 “원격전용 투사무기+근접전용 단병충격무기(세형동검)+근접전용 장병충격무기(동모·동과)”조합 을 이루고 있어서 충주지역이 군장사회로 접어들었음을 보여준다. 이러한 무기조합이 원삼국시대 토 광묘로 이어지는 것도 이를 뒷받침한다.

PURPOSES : This study aimed to analyze the primary maintenance procedures and safety inspection checklist characteristics for suspension bridges. The study referred to the current suspension bridge safety management manual and conducted an on-site safety inspection. By comparing and analyzing any missing or inadequate inspection and management procedures, the study identified major inspection and management areas requiring improvement, and proposed potential solutions. METHODS : The study referred to the current suspension bridge safety management manual and conducted on-site safety inspections. By comparing and analyzing any missing or inadequate inspection and management procedures, the study identified major inspection and management areas requiring improvement, and proposed potential solutions. RESULTS : The study found that suspension bridges are currently inefficiently managed compared to other facilities subject to more rigorous maintenance and safety inspection. Therefore, maintenance and safety inspection procedures require improvement. CONCLUSIONS : For effective safety management and to reduce potential accident risk factors arising from negligent management, major improvements were suggested. Scientific maintenance and safety management could be achieved by incorporating enhancements into statutory requirements and improving management and inspection procedures. This long-term approach is likely to be more economical than the current methods, which lead to higher maintenance and repair costs and increased social costs from traffic accidents.

Animal bones excavated from historic sites provide valuable data for identifying the lifestyles of people and the distribution of animals at that time. In this study, we investigated the morphological structure, size, and measurements of Cervidae bones excavated from a well at the Gasan-ri archaeological site in Jinju, which are believed to be relics from the Three Kingdoms period. The total number of excavated animal bones was 447, of which 102 (22.82%) were classified as Cervidae bones. The weight of Cervidae bones was 453.79 g, accounting for 46.53% of the total weight of the identified bones (975.30 g). The Cervidae bones were identified as those of two animals with an estimated age of 5–6 months. The Cervidae bones are divided into skull bones, vertebrae, ribs, sternum, hip bones, forelimb bones, and hindlimb bones. The 102 Cervidae bones consisted of 19 skull bones (18.63%), 14 vertebral axial skeletons (13.72%), 28 ribs and sternum (28.43%), 16 forelimb bones (15.69%), and 19 hindlimb bones (18.63%). The remaining six were difficult to distinguish. A fracture of the parietal bone located near the bregma of a skull was observed and was presumed to have been caused by an artificial blow. This study can be used as basic data to estimate the types of animals and human culture at the time through Cervidae bones believed to be relics from the Three Kingdoms period.

국내 중·저준위 방사성폐기물은 영구적 격리를 위해 처분장에 매립하고 있으며 그 위치는 경주에 있다. 이러한 방 사성폐기물의 영구적인 격리를 위한 처분시설은 공학적 방벽과 자연 방벽으로 구성되어 있으며 자연 방벽을 특성을 파악 하기 위하여 한국원자력환경공단에서는 2006년부터 부지특성조사를 수행하였고, 이후 부지감시 및 조사계획에 따른 감시 를 수행하여 부지특성의 변화를 지속적으로 확인하고 있다. 중저준위 방폐장의 수리지화학적 환경은 자연 방벽의 평가를 위해 중요한 요소로 손꼽히고 있으나 동해와 가까운 경주의 지역적 특성상 해수의 영향을 반드시 고려해야 한다. 따라서 본 연구에서는 처분 부지의 지하수 관정 7개 및 관정의 심도별 수질 자료를 취합해 지하수 자료 총 30개를 해수 2개소와 비교 분석하여 수리지화학적 환경을 해석하였다. 분석 자료는 수질 10개 항목(온도, EC, HCO3, Na, K, Ca, Mg, Cl, SO4, SiO2)을 2017년 3분기부터 2022년 3분기까지 총 5년간 20회의 자료를 활용하였다. 특히, EC, HCO3, Na, Cl의 농도 변화 를 통해 연구 지역의 배경 농도 및 관정의 구간별 해수의 영향을 파악하였으며, 시계열 군집 분석을 통해 담수, 기수, 해 수의 분류를 시도하였다. 그 결과, 기존의 모니터링 방법으로는 확인하지 못한 부지내 수리지화학적 변화를 제시하였다.

PURPOSES : In this study, the basis for improving the maintenance method of road pavement in Jeju Island, where deterioration is accelerating, was presented through field construction and analysis of various combinations of maintenance methods. METHODS : Construction was performed on Jeju Island's Aejo Road, which has high traffic and frequent early damage, using various asphalt mixtures mainly applied in Jeju Island, with different maintenance cross-sections depending on the level of repair. The quality and performance of the asphalt mixture collected during construction were evaluated, and MEPDG was used to analyze the service life according to the type and maintenance level of the mixture. RESULTS : While the mixture for the surface layer satisfied the quality standards and had excellent rutting and moisture resistance performance, the asphalt mixture for the intermediate and base layer did not satisfy the quality standards such as air voids, so it was judged that quality control was necessary during production. The section repaired to the base layer was found to be advantageous for the integrated behavior of the pavement and had the best structural integrity. As a result of predicting the service life, the estimated life of the section where only the surface layer was repaired was analyzed to be approximately 7 years, the section where the intermediate layer was repaired was 14.5 years, and the section where the entire section up to the base layer was repaired was analyzed to be 18 years. CONCLUSIONS : In Jeju Island, where deterioration is accelerating, it was analyzed that when establishing a maintenance plan, it is necessary to consider repairing the middle and base floors in order to secure the designed life of 10 years.

The effects of La3+ substitution for Sr2+-site on the crystal structure and the dielectric properties of (Ba0.7Sr0.3-3x/2Lax) (Ti0.9Zr0.1)O3 (BSLTZ) (0.005 ≤ x ≤ 0.02) ceramics were investigated. The structural characteristics of the BSLTZ ceramics were quantitatively evaluated using the Rietveld refinement method from X-ray diffraction (XRD) data. For the specimens sintered at 1,550 °C for 6 h, a single phase with a perovskite structure and homogeneous microstructure were observed for the entire range of compositions. With increasing La3+ substitution (x), the unit cell volume decreased because the ionic size of La3+ (1.36 Å) ions is smaller than that of Sr2+ (1.44 Å) ions. With increasing La3+ substitution (x), the tetragonal phase fraction increased due to the A-site cation size mismatch effect. Dielectric constant (εr) increased with the La3+ substitution (x) due to the increase in tetragonality (c/a) and the average B-site bond valence of the ABO3 perovskite. The BSLTZ ceramics showed a higher dielectric loss due to the smaller grain size than that of (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 ceramics. BSLTZ (x = 0.02) ceramics met the X7R specification proposed by the Electronic Industries Association (EIA).

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.

To ensure the maintenance of the nuclear emergency response system, it is important to periodicaly conduct hazard assessments using up-to-date input variables. The results of this review are apllied to drills and exercises, enabling the inspection of emergency plan and response procedures. Therefore, this study aims to analyze off-site consequences according to the occurrence time of the Design Basis Accident (DBA) for the Hanaro Fuel Fabrication Facility (HFFF) by using the recent site-specific meteorological data and to review the appropriateness of urgent protective measures. MELCOR and SafeHanaro computer codes were used for radiation source-term estimation and environmental impact assessment, respectively. It was assumed that radioactive materials are released into environment for 2 hours due to the fire during the nuclear fuel sieving process. The following 12 scenarios for each occurrence time period was selected (0 am, 2 am, 4 am, 6 am, 8 am, 10 am, 12 pm, 2 pm, 4 pm, 6 pm, 8 pm, 10 pm) and the effective dose and thyroid dose in earlyand intermediate-phase were assessed. As a result, the most severe exposure-induced accident scenario is found to be as occurring at 0 am on July 15th, with the Most Exposed Individual (MEI) positioned 200 meters downwind from the facility. The committed effective dose for MEI is identified as to be 2.97E-02 mSv which has a significant margin against the IAEA's (Generic Intervention Level) GIL and (Generic Criteria) GC. During the passage of the radio-active plume, the estimated effective dose and thyroid dose due to inhalation were 2.97E-02 mSV (99.99%) and 5.06E-05 mSv (99.77%), respectively. External exposure appeared to be negligible. Meanwhile, the thyroid dose is noticeably below the criteria for decision-making for distribution of Potassium Iodide (KI). Accordingly, in order for local residents to participate in the exercise and drills, it is essential to develop scenarios considering simultaneous emergencies at multi-facilities and latenight accidents. In conclusion, this results will be used to improve the exercise plans for enhancing the nuclear or radiological emergency competencies of the KAERI.

A new annual dose evaluation system called E-DOSE has been developed. The system is based on the methodology of the previous version, K-DOSE60, which uses the dose evaluation methods of the International Commission on Radiological Protection (ICRP-60). However, E-DOSE is coded in ABAP to be compatible with the KHNP’s enterprise resource planning (ERP) system, SAP. This allows E-DOSE to use the real-time data from SAP, which minimizes the need for user intervention. The socio-environmental data, which was previously managed by the staff of each plant sites, can now managed in the system in a centralized manner. This is a significant improvement over the previous system, as it reduces the risk of errors and makes it easier to track and manage data. The system also automatically generates the reports required by regulations. EDOSE is expected to minimize the occurrence of human errors in preparing and managing the input data. This is because the system uses the data from SAP, which is less prone to errors than manually entered data. Additionally, the automatic generation of reports reduces the risk of errors in report preparation. E-DOSE is also expected to improve work efficiency. This is because the system automates many of the tasks involved in annual dose evaluation, such as data entry, calculation, and report generation. Overall, E-DOSE is a significant improvement over the previous annual dose evaluation system. It is more efficient, accurate, and user-friendly.

To secure approval for a decommissioning plan in Korea, it is essential to evaluate contamination dispersion through groundwater during the decommissioning process. To achieve this, licensees must assess the groundwater characteristics of the facility’s site and subsequently develop a groundwater flow model. It is worth noting that Combustible Radioactive Waste Treatment Facility (CRWTF) is characterized by their simplicity and absence of liquid radioactive waste generation. Given these facility characteristics, the groundwater flow model for CRWTF utilizes data from neighboring facilities, with the feasibility of using reference data substantiated through comparative analysis involving groundwater characteristic testing and on-site modeling. To enable a comparison between the actual site’s groundwater characteristics and the referenced modeling, two types of hydraulic constant characterization tests were conducted. First, hydraulic conductivity was determined through long-term pumping and recovery tests. The ‘Theis’ and ‘Cooper-Jacob’ equations, along with the ‘Theis recovery’ equation, were applied to calculate hydraulic conductivity, and the final result adopted the average of the calculated values. Secondly, a groundwater flow test was conducted to confirm the alignment between the main flow direction of the referenced model and the groundwater flow in the CRWTF, utilizing the particle tracking technique. The evaluation of hydraulic conductivity from the hydraulic constant test revealed that the measured value at the actual site was approximately 1.84 times higher than the modeled value. This variance is considered valid, taking into consideration the modeling’s calibration range and the fact that measurements were taken during a period characterized by wet conditions. Furthermore, a close correspondence was observed between the groundwater flow direction in the reference model (ranging from 90° to 170°) and the facility’s actual flow direction (ranging from 78° to 95°). The results of reference data for the CRWTF, based on the nearby facility’s model, were validated through the hydraulic properties test. Consequently, the modeling data can be employed for the demolition plan of CRWTF. It is also anticipated that these comparative analysis methods will be instrumental in shaping the groundwater investigation plans for facilities with characteristics similar to CRWTF.

As nuclear decommissioning ventures become increasingly complex, the role of digitalization in facilitating and enhancing these operations is becoming indispensable. This transition to a more digitized approach presents a myriad of advantages, including: augmented avenues for data acquisition, analysis, and visualization to bolster dismantling strategies; simulations in virtual environments for operator training; precise forecasting of future waste emergence, culminating in refined cost estimations; and more immersive decommissioning visualizations for both operators and external stakeholders. Salient benefits conferred by the integration of digital technologies in decommissioning encompass improved collaboration, enriched knowledge transfer, clarity regarding present technological constraints, insights into key influencing factors, clearer criteria for technology selection, and a profound understanding of the potential challenges and merits of a broader incorporation of digital tools in decommissioning endeavors. Of paramount importance is the opportunity presented for superior workforce training and safety measures, exemplified by ALARAbased planning. Amidst the myriad facets of digital adoption, 3D modeling of nuclear facilities derived from laser-scanned point clouds stands out as a pivotal domain in the digitalization. The transformation of intricate point cloud data into a comprehensible 3D mesh remains the crux of this paper. The process of mesh generation, despite being simpler than its counterpart of converting to a 3D solid model, is crucial for multiple reasons. The resultant 3D mesh offers an enhanced visual representation compared to a sparse point cloud, paving the way for improved spatial perception. Furthermore, it serves as a rudimentary tool for approximating component volumes and the ensuing waste, thereby playing an instrumental role in waste manipulation strategies, notably in collision detection. This paper delves deep into the nuances of mesh generation, conducting an parametric study of mesh conversion algorithms, including down-sampling rates. Through this rigorous examination, we endeavor to shed light on optimal methodologies, hoping to catalyze advancements in the digitalization of nuclear decommissioning processes.

The operation of nuclear facilities involves the potential for on-site contamination of soil, primarily resulting from pipe leaks and other operational incidents. Globally, decommissioning process for commercial nuclear power plants have revealed huge-amounts of soil waste contaminated with Cs-137, Sr-90, Co-60, and H-3. For example, Connecticut Yankee in the United States produced approximately 52,800 ton of contaminated soil waste, constituting 10% of the total waste generated during its decommissioning. Environmental remediation costs associated with nuclear decommissioning in the US averaged $60 million per unit, representing a significant 10% of the whole decommissioning expenses. Consequently, this study undertook a preliminary investigation to identify important factors for establishing a site remediation strategy based on radionuclide- and site-specific media- characteristics, focusing the efficiency enhancement for the environmental remediation. The factors considered for this investigation were categorized into physical/environmental, socioeconomic, technical, and management aspects. Physical/environmental factors contained the site characteristics, contamination levels, and environmental sensitivity, while socio-economic factors included the social concerns and economic costs. Technical and management factors included subcategories such as technical considerations, policy aspects, and management factors. Especially, technical factors were further subdivided to consider the site reuse potential, secondary waste generation by site remediation, remediation efficiency, and remediation time. Additionally, our study focused the key factors that facilitate the systematic planning for the site remediation, considering the distribution coefficient (Kd) and hydrogeological characteristics associated with each radionuclide in specific site conditions. Therefore, key factors in this study focus the geochemical characteristics of site media including the particle size distribution, chemical composition, organic and inorganic constituents, and soil moisture content. Moreover, the adsorption properties of site media were examined concerning the distribution coefficient (Kd) of radionuclides and their migration characteristics. Furthermore, this study supported the development of a conceptual framework, containing the remediation strategies that incorporate the mobility of radionuclides, according to the site-specific media. This conceptual framework would necessitate the spatial analysis techniques involving the whole contamination surveys and radionuclide mobility modeling data. By integrating these key factors, the study provides the selection and simulation of optimal remediation methods, ultimately offering the estimated amounts of radioactive waste and its disposal costs. Therefore, these key factors offer foundational insights for designing the site remediation strategies according the sitespecific information such as the distribution coefficient (Kd) and hydrogeological characteristics.

For safe and successful decommissioning, it is one of the most important procedures that establishing the goal and complying with regulations of which final status of decommissioned site and building. The dose criteria for cyclotron facilities should be established and applied to reuse the site and building, since building and component of a cyclotron facility have been activated by incident secondary neutrons from radioactive isotope processes (e.g. 18O(p,n)18F, etc.). Furthermore, appropriate approaches should be applied to demonstrate compliance with the dose criteria for reliability of reuse. It is of noted that U.S. NRC (Nuclear Regulatory Commission) has confirmed that the residual radioactivity which distinguishable from background radiation results in a TEDE (Total Effective Dose Equivalent) does not exceed 25 mrem (0.25 mSv) per year as radiological criteria for unrestricted use of not only nuclear power plants but also cyclotron facilities referred to 10 CFR Part 20.1402. In addition, U.S. NRC noted the two approaches (i.e. dose assessment methods and, DCGL and final status surveys) which can be applied for demonstrating compliance with the dose criteria of 10 CFR Part 20 and recommended DCGL and FSS approach based on advantages and disadvantages of the two approaches. In order to using DCGL and FSS approach, U.S. NRC suggested screening approach; using DandD Version 2 which assesses TEDE under ICRP 28 and site-specific approach; using all models or computational codes which approved by NRC staff. There are several foreign cases that release of cyclotron facilities after decommissioning (i.e. U.S. and Japan). U.S., for examples, there are two DCGL approach cases and one dose modeling case based on 25 mrem per year same as reactor facilities. The dose modeling case, however, which may not be really used in Korea because of its low applicability. On the other hand, Japan case did not establish any radiological criteria for site and building reuse such as DCGL and just confirm “no more contamination” which is all residual radioactivity is lower than MDC based on real survey. Japan case also may not be used in Korea since criteria of “no more contamination” is not clear and hard to apply for all sites. Considering regulations and criteria for site release and reuse in Korea, this study aims to suggest radiological criteria and the demonstration approach of compliance for decommissioning of cyclotron facilities based on Nuclear Safety Acts and NSSC notices.

For the release of the nuclear power plant site after the decommissioning, a reliable exposure dose assessment considering the environmental impact of residual radionuclides is essentially required. In this study, the Derived Concentration Guideline Level (DCGL) for the hypothetically contaminated surface soil at the Wolsong nuclear power plant (NPP) unit 1 site was preliminarily calculated by using the RESRAD-OFFSITE computational code and compared with the other case studies. Moreover, radiation exposure dose for local residents and relevant exposure pathways were quantitatively analyzed based on the calculation model established through this work. For the target site modeling, the source term was determined by referring to the previous case studies regarding the nuclear power plant decommissioning, quantification analysis data of pressure tubes of Wolsong NPP unit 1, and radionuclide data estimated by using the MCNP/ORIGEN-2 code. In total, 14 different radioisotopes such as Ag-108m, C-14, Co-60, Cs-134/137, Fe-55, H-3, Nb-93m/94, Ni-63, Sb-125, Sn-121m, Sr-90, and Zr-93 were considered as target radionuclides. In addition, the geological structure model of the Wolsong NPP site was established based on the final safety analysis report of Wolsong NPP unit 1. The distribution coefficients (Kd) were taken from the JAEA-SDB to estimate the migration/retardation behavior of various radionuclides under the groundwater condition of the Wolsong NPP site. In the present work, the DCGL values were calculated according to the site release criterion of 0.1 mSv/yr, which indicates the radiation protection standard for the site release. Moreover, the exposure pathway and sensitivity analyses were conducted to assess the sensitive input parameters remarkably influencing the calculation result. For the evaluation of exposure dose for local residents, a site layout centered around Wolsong NPP unit 4, located in the closest proximity to the residents’ habitation area, was alternatively established and all potential exposure pathways were considered as a comprehensive resident farmer scenario. The results obtained from this study are expected to serve as a preliminary case study for the DCGL values regarding the surface soil at the Wolsong NPP unit 1 site and for evaluating the radiation exposure dose to local residents resulting from the residual radioactivity at the site after the decommissioning.

In light of recent significant seismic events in Korea and worldwide, there is an urgent need to reevaluate the adequacy of seismic assessments conducted during facility construction. This study reexamines the ongoing viability of the Safety Shutdown Earthquake (SSE) criteria assessment for the Combustible Radioactive Waste Treatment Facility (CRWTF) site at the Korea Atomic Energy Research Institute (KAERI), originally established in 1994. To validate the SSE assessment, we delineated 13 seismic structure zones within the Korean Peninsula and employed two distinct methodologies. Initially, we updated earthquake occurrence data from 1994 to the present year (2023) to assess changes in the site’s horizontal maximum earthquake acceleration (g). Subsequently, we conducted a comparative analysis using the same dataset, contrasting the outcomes derived from the existing distance attenuation equation with those from the most recent attenuation equations to evaluate the reliability of the applied attenuation model. The Safety Shutdown Earthquake (SSE) criterion of 0.2 g remains unexceeded, even when considering recent earthquake events since the original evaluation in 1994. Furthermore, when applying various assessment equations developed subsequently, the maximum value obtained from the previously utilized ‘Donvan and Bornstein’ attenuation equation is 0.1496 g, closely resembling the outcome derived from the recently employed ‘Lee’ reduction equation of 0.1451 g. The SSE criteria for CRWTF remain valid in the current context, even in light of recent seismic occurrences such as the 2016 Gyeongju earthquake. Additionally, the attenuation equation employed in the evaluation consistently yields conservative results when compared to methodologies used in recent assessments. Consequently, the existing SSE criteria remain valid at present. This study is expected to serve as a valuable reference for confirming the SSE criterion assessment of similarly constructed facilities within KAERI.