To provide funding for the Portsmouth and Paducah, Tennessee, gaseous diffusion plants.

Authorizes the Secretary of Energy to expend specified funds from the Uranium Enrichment Decontamination and Decommissioning Fund without further appropriation and without fiscal year limitation for payment of decontamination and decommissioning costs, and for remedial action costs.

(Sec. 2) Mandates allocation of such funds to each decontamination and decommissioning program of the gaseous diffusion plants in Portsmouth, Ohio, Paducah, Kentucky, and Oak Ridge, Tennessee, proportional to the total number of Separative Work Units processed at each site.

Sets forth procedural guidelines for possible termination by the United States Enrichment Corporation of its lease with the Department of Energy (DOE).

Instructs the Secretary to transmit a decontamination and decommissioning program for the Portsmouth, Ohio, and Paducah, Kentucky, gaseous diffusion plants after the date a decision has been made to close all or part of one of the gaseous diffusion plants.

(Sec. 3) Directs DOE to establish a Portsmouth and Paducah Operations Office to manage environmental restoration, nuclear energy, and uranium enrichment program activities.

Mandates that the President's Budget request for FY2001 and for each fiscal year thereafter include funding for such Office as a separate line item from the Oak Ridge Operations Office budget.

(Sec. 4) Sets forth closure requirements to minimize social and economic impacts relating to partial or total closures of the Portsmouth, Ohio, and Paducah, Kentucky, gaseous diffusion plants.