For the nuclear non-proliferation strategy as well as the energy production in the spent nuclear fuels, it is proposed to justify the analysis of the Pu/U non-separation characteristics in pyroprocessing. The model of the pyroprocessing development in Korea for nuclear proliferation is constructed successfully. Pyroprocessing is a promising option following the Global Nuclear Energy Partnership as well as the Non-nuclear Proliferation Treaty. In spite of the skeptical review about the Global Nuclear Energy Partnership, it is reasonable for Korea to develop pyroprocessing technology, due to the request for high-level waste repository and the strong necessity of the stable nuclear fuel supply. The possibility of license should be considered, which is the earlier stage comparing to economics, safety, environmental aspect, plant technology, and social acceptance. The volume reduction of spent nuclear fuels is another issue due to the time limitation of the site storage by the year 2016. Recycling of a sodium fast reactor is supposed to develop with pyroprocessing by the year 2040.