Summary: When nuclear facilities are shut down, cleaning up the remains presents special problems because of radioactivity. Responsibility in this area rests primarily with the Energy Research and Development Administration (ERDA) and the Nuclear Regulatory Commission (NRC). ERDA has not given enough attention to its obsolete facilities which have been accumulating. ERDA estimated the cost for decommissioning (disposing of) present excess facilities at $25 to $30 million a year for the next 100 years, but there are not sufficient data to support this estimate. NRC has done little to provide guidance for decommissioning commercial nuclear facilities. It does not require owners to cover costs of future decommissioning; costs could have to be assumed by Federal or State governments. Questions that have not been answered by Federal agencies involve: how much it will cost to decommission facilities, who will pay costs, and how many facilities are involved. Other questions which must be answered relate to methods for decommissioning, possible changes in radiation standards, and the future role of nuclear power. Congress should designate one lead Federal agency to approve and monitor overall decommissioning strategy. ERDA should continue research and development efforts, but NRC is uniquely suited for the lead role.