The search for solutions to two growing crises--human induced climate change and the loss of cheap oil--places nuclear energy front and center. Many see the expansion of nuclear power in the United States as a way to mitigate concerns over energy as well as national and environmental security brought on by the two global problems. Looking at the U.S. nuclear scene's past, present, and future, and focusing on a 21st-century approach to the underlying technical issues, one can see the potential for an expanded nuclear energy future.