The Korean once-through and fast reactor cycles have been analyzed by using the dynamic analysis method. At first a once-through fuel cycle analysis was performed based on Korea's nuclear power plant construction plan up to 2015 and a postulated nuclear demand growth rate by using a logistic model after 2015. The once-through fuel cycle calculation showed that the nuclear power demand would be 46 GWe and the total amount of accumulated spent fuel by 2100 would be similar to 92,000 ton. Second, the fuel cycle parameters of the sodium-cooled fast reactor (SFR) and accelerator driven system (ADS) scenarios were estimated and compared with those of the once-through fuel cycle. The total spent fuel inventories of the SFR and ADS are similar to 37,000 and similar to 9100 ton, respectively. Also, the SFR and ADS can transmute the transuranic elements by 235 and 570 ton, respectively. From the calculation results, it is shown that the fast reactor cycle can effectively reduce the amount of spent fuel accumulation and the inventory of the transuranic elements. (C) 2007 Elsevier Ltd. All rights reserved.