Geologic disposal at deep depth is an acceptable way to dispose of high-level radioactive waste and isolate it from the biosphere. The geological repository system comprises an engineered barrier system (EBS) and the host rock. The system aims to delay radionuclide migration through groundwater flow, and also, the flow affects the saturation of the bentonite in the EBS. The thermal conductivity of bentonite is a function of saturation, so the temperature in the EBS is directly related to the flow system. High-temperature results in the two-phase flow, and the two-phase flow system also affects the flow system. Therefore, comprehending the influencing parameters on the flow system is critical to ensure the safety of the disposal system. Various studies have been performed to figure out the complex two-phase flow characteristics, and numerical simulation is considered an effective way to predict the coupled behavior. DECOVALEX (DEvelopment of COupled models and their VALidation against EXperiments) is one of the most famous international cooperating projects to develop numerical methods for thermo-hydro-mechanicalchemical interaction, and Task C in the DECOVALEX-2023 has the purpose of simulating the Fullscale Emplacement (FE) experiment at the Mont-Terri underground research laboratory. We used OGS-FLAC, a self-developed numerical simulator combining OpenGeoSys and FLAC3D, for the simulation and targeted to analyze the effecting parameters on the two-phase flow system. We focused on the parameters of bentonite, a key component of the disposal system, and analyzed the effect of compressibility and air entry pressure on the flow system. Compressibility is a parameter included in the storage term, defining the fluid storage capacity of the medium. While air entry pressure is a crucial value of the water retention curve, defining the relation between saturation and capillary pressure. From a series of sensitivity analyses, low compressibility resulted in faster flow due to low storage term, while low air entry pressure slowed flow inflow into the bentonite. Low air entry pressure means the air easily enters the medium; hence the flow rate becomes lower based on the relativity permeability definition. Based on the sensitivity analysis, we further investigate the effect of shotcrete around the tunnel and excavation damaged zone. Also, long-term analysis considering heat decay of the radioactive waste will be considered in future studies.

In high-level radioactive waste disposal, a high temperature is generated from the canister containing the waste in the engineered barrier, while groundwater flows into the buffer system from the host rock. The temperature increase and groundwater inflow result in the water phase change and saturation variation. Saturation change is related to the thermal conductivity of buffer material; hence the phase change and saturation strongly interact with the temperature evolution. The complex coupled behavior affects the stability of the whole disposal system, and the security of the repository is critical to human-being life. However, it is difficult to predict the long-term coupled behavior in the disposal system due to the considerable field-test scale, and therefore a numerical simulation is a suitable method having repeatability and cost-effectiveness. DECOVALEX is an international cooperating project for developing numerical methods and models for thermo-hydro-mechanical-chemical (THMC) interaction. DECOVALEX has a four-year cycle with various topics. At the current phase, Task C aims to simulate the full-scale emplacement (FE) experiment performed at Mont Terri underground rock laboratory. Nine research groups are participating in the task, and among them, KAERI simulates the experiment using OGS-FLAC. The simulator combines OpenGeoSys for TH simulation and FLAC3D for M simulation. Through the benchmark simulation, we verified OGS-FLAC for the two-phase flow analysis in the disposal system and finally modeled the FE experiment with a three-dimensional grid. We performed a simple sensitivity analysis to investigate the effect of input parameters on the two-phase flow system and confirmed that the compressibility and permeability affected the flow behavior. We also compared the simulation results to the field data and obtained well-matched results from a series of simulation.

Geologic disposal of high-level radioactive waste is considered the most effective method to isolate high-level radioactive waste from the biosphere. A high-level radioactive waste repository is designed to be placed at a deep depth and generally consists of canisters, buffer material, and host rock. In the disposal system, the heat from the canister occurs for millions of years due to the long half-life of the high-level radioactive waste, and the heat induces vaporization of groundwater in the buffer material. The resaturation process also occurs due to groundwater inflow from the host rock by the hydraulic head and capillarity. The saturation variation leads to the heat transfer and multi-phase flow in the buffer material, and thermal pressurization of groundwater due to the heat affects the effective stress change in the host rock. The stress change can make the porosity and permeability change in the flow system of the host rock, and the flow system affects the nuclide migration to the biosphere. Therefore, it is crucial to understand the complex thermo-hydro-mechanical-chemical (THMC) coupled behavior to secure the repository’s long-term safety. DECOVALEX is an international cooperating project to develop numerical methods and models for predicting the THMC interactions in the disposal systems through validation and comparison with test results. In Task C of DECOVALEX-2023, nine participating groups (BGR, BGE, CAS, ENSI, GRS, KAERI, LBNL, NWMO, Sandia) models the full-scale emplacement (FE) experiments at the Mont Terri underground rock laboratory and focus on understanding pore pressure development, heat transfer, thermal pressurization, vaporization and resaturation process in the disposal system. In the FE experiment, three heaters generated heat with constant power for five years at a 1:1 scale in the emplacement tunnel based on Nagra’s reference repository design. KAERI used OGS-FLAC3D for the numerical simulation, combining OpenGeoSys for TH simulation and FLAC3D for M simulation. We generated a full-scale three-dimensional numerical model with a dimension of 100 by 100 by 60 meters. The pressure and temperature distribution were well simulated with the host rock's anisotropy. Based on the capillarity, we observed vaporization and resaturation in the bentonite under the twophase flow system. We plan to compare the simulation results with the field data and investigate the effect of input parameters, including thermal conductivity and pore compressibility affecting the thermal and flow system.

The purpose of this study was to evaluate the effect of addition of ethylene glycol, glycerol and sucrose to TCG (Tris, Citric Acid, Glucose, Egg Yolk) and DMSO Frozen. The extender containing Egg yolk concentration (10%, 20%) affects viability and acrosome morphology of rabbit sperm. Sperm viability was then assessed for the freezing extenders TCGD (Tris + Citricacid + Glucose + DMSO), TCGED (Tris + Citricacid + Glucose + Egg yolk + DMSO), TCGGD (Tris + Citricacid + Glucose + Glycerol + DMSO) and TCGSD Tris + Citricacid + Glucose + Sucrose + DMSO) during thawing at 38oC. for 20 seconds, respectively. TCG + 10% egg yolk (viability: 77.0 ± 0.8, NAI: 73.3 ± 0.9) was significantly (sperm viability and normal acrosome interaction (NAI)) higher than TCG + 20% egg yolk (70.7 ± 1.1, 70.0 ± 0.9) in the sperm normalcy analysis according to the yolk concentration. TCGGD (53.4 ± 0.1, 62.3 ± 0.4), TCGSD (61.3 ± 0.0, 67.1 ± 0.1) sperm viability and normal acrosome interaction (NAI) in frozen spermatozoa are TCGD (46.4 ± 2.8 and 56.3 ± 1. 4) and TCGED (23.0 ± 1.1 and 54.6 ± 1.4) extenders was thawed at 38oC for 20 seconds. According to the results from each frozen bulking agent, sperm membrane integrity by hypotonic swelling test (HOST) analysis in TCGGD (59.8 ± 0.7), TCGSD (59.3 ± 0.5) was significantly high compared to other experimental groups (p < 0.05). In conclusion, these results suggested that TCGGD and TCGSD extenders enhance survivability of rabbit sperm after frozen-thawing.

Our study has analyzed whether inappropriate gonadotropin secretion affects the morphological changes due to the activation of intrauterine MMP. Methods A total of each 6 mice were injected with PMSG, Progesterone, and Androgen in 5 IU of intraperitoneal injection every 2 days after estrus synchronization, and morphological and MMPs expression patterns were compared after inducing hormone secretion. Also, cell survival and death related genes were compared and analyzed. The endometrium was highly developed in the PMSG, and the androgen was not developed at all. In particular, the diameter of the uterus of the Androgen group was also very narrow. MMPs activity assay in the case of PMSG was confirmed that showed low activity, whereas, progesterone and androgen In showed high activity and, in particular, very high activity of MMPs in the case of androgen in glandular cell. The expression of VEGF in the tissues of each group was different from that of MMPs. In the PMSG group, the activity of VEGF was increased in both the Myo-metrium and the endo-metrium, whereas the progesterone group showed low overall expression in the endo-metrium. Therefore, the present study showed that the activities of the endo-metrial cells and the restructuring of the endometrial cells differed according to the type of the abnormal secretory hormone. In particular, the secretion of androgen increased the activity of MMPs throughout the uterus, The endo-metrial epithelial cells are affected by the progesterone group. In conclusion, this study suggests that inappropriate gonadotropin secretion increases the functional changes of the uterus and this reconstruction may be caused by increased activity of MMPs

The walls of guard cells have many specialized features. Guard cells are present in the leaves of bryophytes, ferns, and almost all vascular plants. However, they exhibit considerable morphological diversities. There are two types of guard cells: the first type is found in a few monocots, such as palms and corn, and the other is found in most dicots, many monocots, mosses, ferns, and gymnosperms. In corns, guard cells have a characteristic dumbbell shape with bulbous ends. Most dicot and monocot species have kidney-shaped guard cells that have an elliptical contour with a pore at its center. Although subsidiary cells are common in species with kidney-shaped stomata, they are almost always absent in most of the other plants. In this study, there were many different stomatal features that were associated with kidney-shaped guard cells, but not dumbbell shaped guard cells, which are present in most grasses, such as cereals. Each plant investigated exhibited different characteristic features and most of these plants had kidney-shaped guard cells. However, the guard cells of Chamaesyce supina Mold, were often more rectangular than kidney-shaped. In contrast, Sedum sarmentosum guard cells were of the sink ensiform type and in Trifolium repens, the guard cells exhibited a more rhombic shape. Therefore, kidney-shaped guard cells could be divided into a number of subtypes that need to be investigated further.

This study is designed to assess the priority order of the chemicals to cause to generate occupational diseases in order to understand the fundamental data required for the preparation of health protective measure for the workers dealing with chemicals. The 41 types of 51 ones of chemicals to cause to generate the national occupational diseases were selected as the study objects by understanding their domestic use or not, and their occupational diseases' occurrence or not among 110,608 types of domestic and overseas chemicals. To assess their priority order the sum of scores was acquired by understanding the actually classified condition based on a perfect score of physical riskiness(90points) and health toxicity(92points) as a classification standard by GHS, the priority order on GHS riskiness assessment, GHS toxicity assessment, GHS toxic․riskiness assessment(sum of riskiness plus toxicity) was assessed by multiplying each result by each weight of occupational disease's occurrence. The high ranking 5 items of chemicals for GHS riskiness assessment were turned out to be urethane, copper, chlorine, manganese, and thiomersal by order. Besides as a result of GHS toxicity assessment the top fives were assessed to be aluminum, iron oxide, manganese, copper, and cadium(Metal) by order. On the other hand, GHS toxicity․riskiness assessment showed that the top fives were assessed to be copper, urethane, iron oxide, chlorine and phenanthrene by order. As there is no material or many uncertain details for physical riskiness or health toxicity by GHS classification though such materials caused to generate the national occupational diseases, it is very urgent to prepare its countermeasure based on the forementioned in order to protect the workers handling or being exposed to chemicals from health.