If radioactive plumes are released outside due to loss of containment building integrity during a nuclear power plant accident, these materials might travel with the wind, affecting both the surrounding environment and neighboring countries. In China, most nuclear power plants are located on the eastern coast. Consequently, a radioactive plume generated during an accident could negatively impact even the western part of the Korean Peninsula due to westerly winds. To detect such problems early, respond quickly, and protect residents, a system that can monitor aerial radiation under normal conditions is needed. Additionally, a detection system that can operate in real-time in an emergencies conditions is required. The current method for aerial radiation measurement takes environmental radiation data from a monitoring post 1.5 m above the ground and converts it to altitude. To measure actual aerial radiation, an expansive area is surveyed by aircraft. However, this approach is both time-consuming and expensive. Thus, to monitor radioactive plumes influenced by environmental factors like wind, we need a radiation detector that can gauge both radioactivity and directionality. In this study, we developed a radiation detector capable of assessing both the radioactivity and directionality of a radioactive plume and conducted its performance evaluation. We miniaturized the radiation detector using a CZT (Cadmium Zinc Telluride) sensor, enabling its mounting on unmanned aerial vehicles like drones. It is configured with multi-channels to measure directionality of a radioactive plumes. For performance evaluation, we positioned two-channel CZT sensors at 90 degrees and measured the energy spectrum for angle and distance using a disk-type radioactive isotope. Using this method, we compared and analyzed the directionality performance of the multi-channel radiation detector. We also confirmed its capability to discern specific radioactivity information and nuclide types in actual radioactive plumes. Our future research direction involves mounting the multi-channel radiation detector on a drone. We aim to gather actual aerial radiation data from sensors positioned in various directions.
Decommissioning waste is generated with various types and large quantities within a short period. Concrete, a significant building material for nuclear facilities, is one of the largest decommissioning wastes, which is mixed with aggregate, sand, and cement with water by the relevant mixing ratio. Recently, the proposed treatment method for volume reduction of radioactive concrete waste was proven up to scale-up testing using unit equipment, which involved sequentially thermomechanical and chemical treatment. According to studies, the aggregate as non-radioactive material is separated from cement components with contaminated radionuclides as less than clearance criteria, so the volume of radioactive concrete waste is decreased effectively. However, some supplementation points were presented to commercialize the process. Hence, the process requires efficiency as possible to minimize the interface parts, either by integration or rearranging the equipment. In this study, feasibility testing was performed using integrated heating and grinding equipment, to supplement the possible issue of generated powder and dust during the process. Previously, heat treatment and grinding devices were configured separately for pilot-scale testing. But some problems such as leakage and pipe blockage occurred during the transportation of generated fine powder, which caused difficulties in maintaining the equipment. For that reason, we studied to reduce the interface between the equipment by integrating and rearranging the equipment. To evaluate the thermal grinding performance, the fraction of coarse and concrete fines based on 1mm particle size was measured, and the amount of residual cement in each part was analyzed by wet analysis using 4M hydrochloric acid. The result was compared with previous studies and the thermomechanical equipment could be selected to enhance the process. Therefore, it is expected that the equipment for commercialization could be optimized and composed the process compactly by this study.
Entomopathogenic fungi are used to produce raw materials by applying solid culture technology using grains. But there are various problems such as low production efficiency and cross-contamination. Solvum Co., Ltd. conducted research on liquid culture technology to develop a method that can overcome these shortcomings of solid culture technology. We conducted research and development on using Beauveria bassiana 331R to observe the culture according to the seed inoculation amount in a 30 L fermenter, it was carried out at 1.0 % (v/v) and 10.0 % (v/v). Although there was a difference of 1 day, 1.0 %(v/v) seed inoculation was observed to be more than twice that, and active blastospores and yield were observed at over 95.0 %. As a results, it was determined that cost and efficient production would be possible during the culture process in mass production. Based on these experiments, a 300 L fermenter was cultured with 1.0 % (v/v) seed inoculation, resulting in a yield of 1.24E+09 CFU/mL on the 6th day of cultivation. As a result of freeze-drying using the final culture medium, it was confirmed that the production yield was improved by 113.0 % compared to the control.
This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.0104 cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 105 cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.
Mucosa-associated lymphoid tissue (MALT) lymphoma (ML) is a type of non-Hodgkin’s lymphoma involving MALT, commonly the stomach or salivary glands, although virtually any mucosal site can be affected. ML originates from B cells in the marginal zone of MALT, and is also called extranodal marginal zone B cell lymphoma. It is a slow-growing cancer that usually responds well to treatment. A 59-year-old female presented with a 1-day history of quadriparesis and dysarthria. Up arrival at the hospital, motor power in the right upper and lower extremities was grade 3/5 according to the Medical Research Council scale, while that in the left leg was 4/5. The patient had been diagnosed with gastric ML 1 year prior, and had received antibiotics during the previous 2 weeks. The emergency magnetic resonance imaging of the brain performed at the time of presentation showed multifocal embolic infarction in the cerebral hemisphere bilaterally, which did not have a cardiac origin. Magnetic resonance angiography revealed no stenotic or occlusive lesions. Secondary prophylaxis with daily administration of 300 mg aspirin was prescribed. The patient was discharged with residual right hemiparesis 2 weeks after the onset of symptoms. Herein, we present a rare case of multifocal cerebral infarction in a gastric ML patient.