• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.5
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• pp.587-609
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• 2019

Short-and long-term stabilities of bentonite, favored material as buffer in geological repositories for high-level waste were reviewed in this paper in addition to alternative design concepts of buffer to mitigate the thermal load from decay heat of SF (Spent Fuel) and further increase the disposal efficiency. It is generally reported that the irreversible changes in structure, hydraulic behavior, and swelling capacity are produced due to temperature increase and vapor flow between $150{\sim}250^{\circ}C$. Provided that the maximum temperature of bentonite is less than $150^{\circ}C$, however, the effects of temperature on the material, structural, and mineralogical stability seems to be minor. The maximum temperature in disposal system will constrain and determine the amount of waste to be disposed per unit area and be regarded as an important design parameter influencing the availability of disposal site. Thus, it is necessary to identify the effects of high temperature on the performance of buffer and allow for the thermal constraint greater than $100^{\circ}C$. In addition, the development of high-performance EBS (Engineered Barrier System) such as composite bentonite buffer mixed with graphite or silica and multi-layered buffer (i.e., highly thermal-conductive layer or insulating layer) should be taken into account to enhance the disposal efficiency in parallel with the development of multilayer repository. This will contribute to increase of reliability and securing the acceptance of the people with regard to a high-level waste disposal.

• Journal of the Daesoon Academy of Sciences
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• v.27
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• pp.283-317
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• 2016

This research is an attempt to detail the multi-layered ethical characteristics of 'mutual beneficence', shown in the principle of 'guarding against self-deception' in Daesoon Thought while focusing on its major differences as well as the similarities with Kantian and Utilitarian ethical views. In these Western ethical perspectives, the concept of self-deception has received a considerable amount of attention, centering on the context of natural rights and contract theory. Meanwhile, in Daesoon Thought, 'guarding against self-deception' is presented as one of the principal objectives as well as the method or deontological ground for practice. It further encompasses the features of virtue ethics oriented toward the perfection of Dao. Here, the deontological aspect is interlinked with the concept of cultivation and the pursuit of ethics and morals. Hence this makes it a necessary condition for achieving the perfection of Dao, and likewise renders the practice of 'guarding against self-deception' more active through facilitating mutual relations based on the expansion model wherein human nature is characterized as possessing innate goodness. With regard to the tenet of 'resolution of grievances for mutual beneficence,' this concept is presented as a positive ground for practicing virtues toward others without forming grudges. Furthermore, as long as it reveals the great principle of humanity built on conscience, it will come to harmonize practitioners with others and spirits in an expression of beneficence. Moreover, originating in the Dao of Deities, guarding against self-deception is expressed as a form of life ethics and can be suggested as a new alternative for the model of virtue ethics proposed by Nussbaum. All in all, there is a natural causal relationship by which 'guarding against self-deception' in accord one's own conscience and the principle of humanity as a pursuit of perfect virtues in Dao result in the fulfillment of mutual beneficence. This readily akin to how gravity causes water to flow from high ground to low ground. Consequently, these relational features of mutual beneficence can serve an effective alternative to the Western ethical views which also address the need to overcome the egoistic mind which is liable to self-interest and alienation.