[en] Study groups have recently attempted to analyze the issues offered by proponents of halting nuclear power plant construction and those offered by groups in favor of nuclear energy. This paper also analyzes trade-offs, two alternative futures or scenarios for the U.S. being examined: one in which nuclear energy continues to grow at fairly rapid rates vs. one in which nuclear power plants currently operating and those actually under construction are allowed to operate for a normal lifetime but construction of any additional plants is halted. When it is possible and whenever it seems reasonable, the approach taken in this paper is to quantify the relevant trade-offs over the next 50-year period. While this time period is too short to observe the full, ultimate consequences of a nuclear energy phaseout, anything longer would reduce confidence in results to a level too low to make the effort worthwhile. The approach involves consideration of likely developments in each of the major factors that can influence the future in order to determine which assumptions are most reasonable to include in the projection exercise. These assumptions are then incorporated into a model of the U.S. economy that is run for each of the two alternative scenarios in order to estimate the relevant trade-offs. The model and key assumptions used in running both scenarios are described. Results are then compared first in terms of economic and resource impacts and then in terms of environmental impacts. Finally, trade-offs between the two scenarios are reviewed and conclusions given