The United States is facing unprecedented challenges in climate change and energy security. President-elect Obama has called for a reduction of CO2 emissions to 1990 levels by 2020, with a further 80% reduction by 2050. Meeting these aggressive goals while gradually increasing the overall energy supply requires that all non-emitting technologies must be advanced. The development and deployment of nuclear energy can, in fact, help the United States meet several key challenges: (1) Increase the electricity generated by non-emitting sources to mitigate climate change, (2) Foster the safe and proliferation-resistant use of nuclear energy throughout the world, (3) Reduce the transportation sectors dependence on imported fossil fuels, and (4) Reduce the demand on natural gas for process heat and hydrogen production. However, because of the scale, cost, and time horizons involved, increasing nuclear energys share will require a coordinated research effortcombining the efforts of industry and government, supported by innovation from the research community. This report outlines the significant nuclear energy research and development (R&D) necessary to create options that will allow government and industrial decision-makers to set policies and create nuclear energy initiatives that are decisive and sustainable.