Lubricant oil waste contaminated with radioactive materials generated at nuclear facilities can be disposed of as industrial waste in accordance with self-disposal standards if only radioactive materials are removed. Lubricant oil used in nuclear facilities consists of oil of 75-85% and additives of 15-25%, and lubricant oil waste contains heavy metals, carbon, glycol, etc. In addition, lubricant oil waste from nuclear facilities contains metallic gamma-ray emission radionuclides including Co-60, Cs-137 and volatile beta-ray emission radionuclides such as C-14 and H-3, which are not present in lubricant oil waste from general industries and these radionuclides must be eliminated according to the Atomic Energy Act. In general industries, the wet treatment technologies such as acid-white soil treatment, ion purification, thin film distillation, high temperature pyrolysis, etc. are used as the refining technology of lubricant oil waste, but it is difficult to apply these technologies to nuclear industrial sites due to restrictions related with controlling the generation of secondary radioactive waste in sludge condition containing radionuclides of metal components, and limiting the concentration of volatile radioactive elements contained in refined oil to be below the legal threshold. In view of these characteristics, the refinement system capable of efficiently refining and treating lubricant oil waste contaminated with radioactive materials generated in nuclear facilities has been developed. The treatment process of this R&D system is as follows. First, the moisture in the radioactive lubricant oil waste pretreated through the preprocessing system is removed by the heated evaporating system, and the beta-emission radionuclides of H-3 and C-14 can be easily removed in this process. Second, the heated lubricant oil waste by the heated evaporating system is cooled through the heat exchanging system. Third, the particulate matters with gamma-ray emission radionuclides are removed through the electrostatic ionizing system. Forth, the lubricant oil waste is stored in the storage tank and the purified lubricant oil waste is discharged to the outside after sampling and checking from the upper, middle and lower positions of the lubricant oil waste stored in the storage tank. Using this R&D system, it is expected that the amount of radioactive waste can be reduced by efficiently refining and treating lubricant oil waste in the form of organic compounds contaminated with radioactive materials generated in nuclear facilities.

Encapsulation using cement as a solidification method for disposal of radioactive waste is most commonly used in most advanced countries in the nuclear technology to date due to its advantages such as low material cost and accumulated technology. However, in case of cement solidification, since moisture or hydroxyl group in cement is decomposed by radioactivity, it may happen that gas is generated, structural stability is weakened, and leachability is increased due to low chemical durability. Therefore, the various new solidification methods are being developed to replace it. As one of these alternative technologies, for dispersible metal compounds generated through the incineration replacement process, the study on engineering element technology for powder metallurgy is under way, which overcomes the interference problem between mechanical elements and media that may occur during the process such as the homogeneous mixing process of the target powder substance and additives used in the powder metallurgy concept-based sintering process for the solidification of the final glass composite material (GCM), the process of creating a compressed molded body using a specific mold, the process of final sintering treatment. The solidification process of dispersible radioactive waste can be largely divided into pre-treatment stage, molding stage, and sintering stage, and the characteristics of the final radioactive waste solidification material can vary depending on the solidification treatment characteristics of each stage. In relation with these characteristics, the matters to be considered when designing device for each stage to solidify dispersible radioactive waste (property of super-mixing device for homogenized powder formation, structural geometry and pressure condition of molding device for production of compressed molded body, temperature and operation characteristics of sintering device for final glass composite material (GCM), etc.) are drawn out. It is expected that the solidification device design reflecting these considerations will meet all disposal conditions of radioactive waste material, such as compressive strength and leaching characteristics of solidified radioactive waste material, and create a uniformized solidification of radioactive waste material.

Arabidopsis nucleoside diphosphate kinase 2 (AtNDPK2) is an upstream signaling molecule that has been shown to induce stress tolerance in plants. In this study, the AtNDPK2 gene, under the control of a stress-inducible SWPA2 promoter, was introduced into the genome of tall fescue (Festuca arundinacea Schreb.) plants. The induction of the transgene expression mediated by methyl viologen (MV) and NaCl treatments were confirmed by RT-PCR and northern blot analysis, respectively. Under salt stress treatment, the transgenic tall fescue plants (SN) exhibited lower level of H2O2 and lipid peroxidation accumulations than the non-transgenic (NT) plants. The transgenic tall fescue plants also showed higher level of NDPK enzyme activity compared to NT plants. The SN plants were survived at 300 mM NaCl treatment, whereas the NT plants were severely affected. These results indicate that stress-inducible overexpression of AtNDPK2 might efficiently confer the salt stress tolerance in tall fescue plants.

Environmental stress is a growing problem for the productivity of forage crops. Reactive oxygen species (ROS) formation due to several abiotic stresses is a fundamental process that interrupts several physiological processes and causes a significant reduction on growth and yield of many forage crops. Molecular breeding such as genetic transformation has become a popular biotechnological tool for improving forage quality as well as improves tolerance to various abiotic stresses. As a first step of genetic transformation in tall fescue, we established an efficient Agrobacterium-mediated genetic transformation protocol using mature seed-derived embryogenic callus. After optimization of the transformation system, several genes of interest have been used to generate abiotic stress tolerant forage grasses. We generated transgenic tall fescue plants expressing NDPK genes under the control of the oxidative stress-inducible SWPA2 promoter. Transgenic plants showed enhanced tolerance to several abiotic stresses. Results in the current study, suggest that NDPK mediated multiple stress tolerance by increasing the expression of genes involved in antioxidant and protective functions, possibly through activation of an MAPK cascade.

The molecular responses to various abiotic stresses were investigated by the approaches with transcriptomic analysis based on an ACP system. Here we identified differentially expressed genes under abiotic stresses in alfalfa seedlings and they were mostly unknown genes and a few common stress-related genes. Among them, mitochondrial small HSP23 was responded by the diverse stress treatment such as heat, salt, As stresses and thus it could be a strong candidate that may confer the abiotic stress tolerance to plants. When expressed in bacteria, recombinant MsHSP23 conferred tolerance to salinity and arsenic stress. Furthermore, MsHSP23 was cloned in a plant expressing vector and transformed into tobacco, a eukaryotic model organism. The transgenic plants exhibited enhanced tolerance to salinity and arsenic stress under ex vitro conditions. In comparison to wild type plants, the transgenic plants exhibited significantly lower electrolyte leakage. Moreover, the transgenic plants had superior germination rates when placed on medium containing arsenic. Taken together, these overexpression results imply that MsHSP23 plays an important role in salinity and arsenic stress tolerance in transgenic tobacco. The results of the present study show that overexpression of alfalfa mitochondrial MsHSP23 in both eukaryotic and prokaryotic model systems confers enhanced tolerance to salt and arsenic stress. This indicates that MsHSP23 could be used potentially for the development of stress tolerant transgenic crops, such as forages.

The dramatic increase in population accompanied by rapid industrialization in developing countries including China has caused imbalances in the supply of food and energy. To cope with these global crises over food and energy supplies as well as environmental problems, it is urgently required to develop industrial GM crops to be grown in marginal lands including desertification and polluted lands for sustainable agriculture. Recently we developed several tansgenic crops such as sweetpotato (Ipomoea batatas L. Lam), potato (Solanum tuberosum L.), tall fescue (Festuca arundinacea Schreb.) expressing genes of both Cu/Zn superoxide dismutase and ascorbate peroxidase in the chloroplasts under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter (referred to SSA plants). SSA plants showed a strong tolerance to oxidative stress caused bythe application of methyl viologen (MV, paraquat), a ROS-generating non-selective herbicide. SSA sweetpotato plants showed higher tolerance to chilling stress than non-transgenic (NT) plants, whereas SSA potato plants showed higher tolerance to high temperature. SSA sweetpotato plants showed a strong tolerance to the application of sulfur dioxide (500 ppb) compared to NT plants. Enhanced tolerance of transgenic crops expressing NDP kinase 2 in cytosols under SWPA2 promoter (SN plants) to environmental stress will be introduced. In addition, the strategies for sustainable agriculture in marginal areas will be discussed

Plant peroxidases (PODs) have been shown to reduce hydrogen peroxide (H2O2) in the presence of an electron donor. Extracellular POD also induce H2O2 production, and can perform a significant function in responses to environmental stresses. We previously described the isolation of 10 POD cDNA clones from cell cultures of sweetpotato (Ipomoea batatas). Among them, the expression of the swpa4 gene was profoundly induced by a variety of stresses. In this study, transgenic tobacco (Nicotiana tabacum) plants overexpressing the swpa4 gene under the control of the CaMV 35S promoter were generated in order to assess the function of swpa4. Both transient expression analysis with the swpa4-GFP fusion protein and POD activity assays in the apoplastic washing fluid revealed that the swpa4 protein is secreted into the apoplastic space. The transgenic plants also evidenced a significantly enhanced tolerance to a variety of abiotic and biotic stresses. These plants harbored increased lignin and phenolic content, and H2O2 was also generated under normal conditions. Furthermore, they manifested increased expression levels of a variety of apoplastic acidic pathogenesis-related (PR) genes following enhanced H2O2 production. These results suggest that the expression of swpa4 in the apoplastic space functions as a positive defense signal in the H2O2-regulated stress response signaling pathway.

Four urushiol components isolated from the sap of Korean lacquer tree(Rhus vernicifera Stokes) showed a strong antifungal activity, but they have no or low activity the bacteria and yeasts. Among them, 3-pentadecylcatechol marked the highest activity on the spore germination of Cladosporium herbarum (MIC:4μg/ml).