An acceptable long-term solution for used (spent) fuel from nuclear power reactors has evaded all countries engaged in the civilian nuclear fuel cycle. Furthermore, many countries are trying to develop interim storage solutions that address the shortage of storage in the spent fuel cooling pools at reactors. The United States has a particularly acute problem due to its adherence to an open fuel cycle and its large number of reactors. Two main options are available to address the spent fuel problem: dry storage on-site at reactors and centralized storage at a facility away from reactors. Key to deciding which option makes better policy sense is the comparative economics of the two options. This paper provides one of the few comprehensive comparisons of costs for the two alternatives and discusses implications for other schemes and possible alternative solutions to the spent fuel problem for the United States.