Advanced nuclear R&D efforts and programs in the Republic of Korea have generally focused on sodium-cooled fast reactors (SFRs), although there has also been some work on very-high-temperature reactors (VHTRs). Although a wide range of advanced reactor and Generation-IV designs were originally considered, the SFR was selected for its technological maturity, actinide burning capabilities, and enhanced safety characteristics. While the SFR was initially planned as a support reactor for the conventional LWR fleet, policy changes have led to a greater emphasis on the SFR’s spent fuel management mission and transuranic (TRU) burning role. Key decisions on the SFR program in Korea will be made once the national policy on spent nuclear fuel (SNF) management has been determined. Further work is currently being conducted on further enhancing the SFR’s passive safety profile and transmutation capabilities, and studies are being done on the Pyroprocessing-SFR fuel cycle’s economics and proliferation resistance. The ultimate goal of these R&D efforts as a whole is the elimination of the need of emergency offsite response and limiting the consequences of any incidents to within site boundaries—extremely important considering issues related to social acceptance. In the future, R&D will focus on non-electricity applications, including hydrogen production, and other Generation-IV types.