Thermal analysis and safety assessment of spent fuel transport cask are mainly conducted using commercial Computational Fluid Dynamics (CFD) codes based on Finite Volume Method (FVM). The reliability and predictability of CFD codes have greatly been improved by the development in the computer systems, and are widely used to calculate heat flow in complex structures that cannot be analyzed theoretically. In the field of thermal analysis using the CFD code, it is important to clearly reflect the physical model of the transport cask, and a grid configuration suitable for the physical model is essential for accurate analysis. However, since there are no clear standard and guidelines for grid configuration and size, it is highly dependent on the user’s insight. Spatial discretization errors result from the use of finite-width grids and the approximation of the differential terms in the model equations by difference operators. Since the user usually cannot change the truncation error order of a given discretization scheme, spatial discretization errors can only be influenced by the provision of optimal grids. Therefore, it is necessary to quantify the spatial discretization errors caused by the grid. In the case of Orano TN’s NUHOMS® MP197 transport cask, considering four grids for two sets, the temperature uncertainty of the neutron shield, which has the lowest margin at the limit temperature among transport cask components, was quantified by applying 5-step procedure of the Grid Convergence Index (GCI) method for the uncertainty estimation presented in ASME V&V 20-2009. In the case of domestic spent nuclear fuel transport cask (KORAD21), neutron shield among the transport cask components has the lowest margin at the limited temperature. Accordingly, in this study, the temperature uncertainty of the neutron shield was quantified by applying GCI to three sets considering seven grids. As a result of the calculation, the uncertainty was less than ± 1°C, and the temperature of the neutron shield including the uncertainty was evaluated to be maintained below the limit temperature of 148°C.

We determined the effects of different water temperatures (15, 20, and 25℃) and photoperiod cycles (24L:0D, 12L:12D, and 0L:24D) on the oxygen consumption of the offspring of a cultured Japanese strain (JJ), a selected Korean strain (KK), and intraspecific hybrid strains (JK and KJ) of red seabream, Pagrus major, under starvation conditions. The different fish strains, water temperatures, and photoperiod cycles had effects on the mean oxygen consumption of fish. Oxygen consumption increased with increasing water temperatures for all photoperiod treatments (p <0.001). Fish held in continuous darkness (0L:24D) used consistently less oxygen than fish exposed to continuous light (p <0.05). The oxygen consumption of fish exposed to the light phase in a 12L:12D photoperiod was higher than that of fish in the dark phase of the 12L:12D cycle, and differences were significant in three of the strains: JJ (15℃), KK (15 and 20℃), and KJ (25℃). The oxygen consumption of the inbred (JJ and KK) and intraspecific hybrid (JK and KJ) strains varied with differing water temperatures and photoperiod cycles. The JK strain displayed significantly higher oxygen consumption than the other strains under all experimental conditions except 15℃ with a 0L:24D photoperiod. The JK and KJ strains usually showed the highest and lowest oxygen consumption values, respectively, whereas the inbred strains exhibited intermediate values. Oxygen consumption in the JJ and JK strains was usually higher than that of the KK and KJ strains. We propose that differences in the thermal sensitivity and photosensitization properties of the strains contribute to differences in their ability to adapt to changes in water temperature and photoperiod, thus resulting in differences in the amplitude of their metabolic rates.

The maritime education and training is executed in Asian countries according to The International Convention on Standards of Training, Certification and Watch keeping for Seafarers(STCW). However, mainly basic training and education takes in maritime universities, because this convention is minimum requirements to become junior mariner. So, until now researches have not developed to the stage of discussing how maritime universities of advanced shipping countries should pursue the direction of education in the new eras. Korea and Japan as the leading shipping countries in Asia, need to take initiatives in building a new education system in order to foster the next generation maritime expert. To enhance the professional abilities of maritime technologists in the new era, element design of science and technology relating to maritime issues and a new education system based on an amalgamation of maritime education and scientific and technological education were discussed.