Two sets of analyses for the cases of groundwater release to well and sea ecosystems were conducted for the environmental impact assessment of high-level radioactive waste disposal facilities. After obtaining the respective BDCF (Biosphere Dose Conversion Factor) results for the scenarios of well-farming and marine water fishing using different biosphere assessment conceptual models implemented in ECOLEGO, they were compared each other. The purposes of these analyses are to identify reference generic biosphere conceptual models and to get insight on model uncertainty. In this study, the endpoint used for the comparison of the ECOLEGO biosphere models was the socalled Biosphere Dose Conversion Factor (BDCF), which is defined as the maximum value of the total dose to the exposed group, in Sv/yr, resulting from a continuous unit release of 1 Bq/yr during the whole simulation time either to the well compartment (BDCF_Well) or to the marine water compartment (BDCF_Sea). The radionuclides considered in the comparison were Cs-137, I-129, Nb-94, Ni-59, Ni- 63, Sr-90 and Tc-99. The conceptual models used in the biosphere assessment of the releases to a well are based on models that have been used by the DOE (simple-soil model) and SKB (complex-soil model) in safety assessments of radioactive waste repositories, respectively. Difference between two conceptual models used in the assessment of the releases to a sea is the number of compartments representing the sea; i.e., one model represents the sea with one compartment for the water and one for the sediment (singlecompartment model), whereas the alternative model uses two compartments for the water and the sediments: one for the inner coast and one for the outer coast (double-compartment model). The results of the BDCF_Well to a farmer obtained with the DOE and SKB models are shown to be very close to each other. Despite the differences in conceptual models and parameters, the results are within a maximum difference of a factor of 4. The results from the SKB model were higher for all radionuclides. The values of the BDCF_Sea obtained with the single- and double-compartment models are shown to be larger differences with a maximum order of 2. For all studied radionuclides, the double-compartment model produces higher BDCFs than does the single-compartment model. The differences would be due to activity concentrations in both water and sediments. Since the hydrodynamic behavior assumed for flow in the sea could significantly influence the dilution volumes and hence the concentrations, it is found that site-specific investigations are necessary to establish an appropriate marine biosphere conceptual model.

IAEA safety standards document and international programs (such as BIOMASS) related to the assessment of the biosphere around High Level Radioactive Waste (including Spent Nuclear Fuel) repositories require the assessment of the biosphere to use the assumption that the current natural environment and human society will be maintained, and at the same time, the evolution of the distant future changes also need to be taken into account. In Korea, which has not designated candidate disposal sites, it is necessary to investigate and predict the current state and future changes of the natural environment throughout Korea and apply it practically to Biosphere assessment (for BDCF derivation) for candidate disposal sites suitability assessment and Safety Case (for performance assessment) preparation for design, construction, operation, and post-closure management. To this end, the natural environment in the fields of Topography, Geology, Soil, Ecology, Weather and Climate, Animals and Plants, Hydrology, Ocean, Land-use, etc. and human society in the fields of Population Distribution, Spatial-Planning, Urban Form, Industrial-Structure, Lifestyle etc. are being investigated in the context of current status, past change records, and future change potential in the Korean Peninsula. This paper summarizes those investigations to date. This study referred Biomass-6 [IAEA] and National Atlas I (2019)/II (2020)/III (2021) [National Geographic Information Institute of the Korea Ministry of Land, Infrastructure and Transport].

As part of the safety case development for generic disposal sites in Korea, it is necessary to develop generic assessment models using various geosphere–biosphere interfaces (GBIs) and potentially exposed groups (PEGs) that reflect the natural environmental characteristics and the lifestyles of people in Korea. In this study, a unique modeling strategy was developed to systematically construct and select Korean generic biosphere assessment models. The strategy includes three process steps (combination, screening, and experts’ scoring) for the biosphere system conditions. First, various conditions, such as climate, topography, GBIs, and PEGs, were combined in the biosphere system. Second, the combined calculation cases were configured into interrelation matrices to screen out some calculation cases that were highly unlikely or less significant in terms of the exposure dose. Finally, the selected calculation cases were prioritized based on expert judgment by scoring the knowledge, probability, and importance. The results of this study can be implemented in the development of biosphere assessment models for Korean generic sites. It is believed that this systematic methodology for selecting the candidate calculation cases can contribute to increasing the confidence of future site-specific biosphere assessment models.

최근 건축물의 노후화에 따라 리모델링이 증가하고 있다. 이에 구조물의 품질관리 중요성이 대두되어 구조물의 안전진단 및 상태평가에 대한 관심이 증가되고 있다. 노후건축물의 정확한 진단을 위해서 구조물의 결함을 사전에 평가할 수 있는 진단평가기법이 필요하다. 이와 더불어 재건축을 위한 안전진단 기준이 개선되어 구조안전성의 가중치가 증가함에 따라 보다 신속하고 신뢰성 높은 구조물의 안전진단기법에 대한 연구가 필요한 실정이다. 초음파속도법을 이용하여 압축강도를 추정하는 연구는 공시체를 기반으로 한 연구들이 주로 이루어져 왔으며 실제 건축물이나 콘크리트 구조부재를 대상으로 한 연구는 부족한 실정이다. 본 연구에서는 비파괴검사법 중 하나인 초음파속도법을 이용하여 철근콘크리트 수직 및 수평부재로 구성된 단층 규모의 구조물을 대상으로 초음파속도와 압축강도의 상관관계를 검증하여 압축강도를 추정하고자 하며, 또한 이를 바탕으로 현장 적용성을 검토하고자 하였다. 그 결과, 초음파속도법을 이용한 구조체의 압축강도 추정 평균 오차율은 28.7%로 현장 적용성을 확인하였다. 그러나 추정의 정확도를 높이기 위하여 복합 비파괴검사법을 이용한 신뢰도 높은 진단기법의 필요성을 확인하였다.

Estrogens are ubiquitous signaling molecules that influence nearly every cell type, and exert profound effects on embryonic development, and differentiation. Wnt pathway, which recruits β-catenin into nuclei, and activates The Wnt-dependent transcription factors, also plays an important role in embryonic development and stem cell maintenance, and differentiation. Accumulating evidences indicate that potential convergence between these two pathways in carcinoma cells. However, physiological roles of estrogens in development and differentiation of human embryonic stem cells (hESCs) are relatively unknown. Here, we demonstrated that estrogenic compounds 17α-ethinylestradiol (EE2) and genistein (GEN) significantly increased β-catenin expression in undifferentiated hESCs cultured in feeder-free media. Interestingly, GEN treatement induced an increased trend of mesendodermal gene expressions, and significantly inhibited ectodermal gene expressions (Nestin and Pax6) in embrioid body (EB). Expectantly, GEN increased epithelial-mesenchymal transition (EMT) related gene expression (Snail2, and Twist), whereas decreased E-cadherin on day 6 of EB development. Taken together, these suggest that estrogens may in part the powerful effects on normal hESC differentiation. Mechanistic studies of estrogen signaling continue to suggest novel drug targets for stem cells and will also improve screening methods of developmental toxicity.