In This Issue
Fall Issue of The Bridge on Nuclear Energy Revisited
September 15, 2020 Volume 50 Issue 3
The desire to reduce the carbon intensity of human activities and strengthen the resilience of infrastructure key to economic prosperity and geopolitical stability shines a new spotlight on the value and challenges of nuclear energy.

Foreword Nuclear Energy: Context and Outlook

Monday, September 21, 2020

Author: Ashley Finan

Humankind faces significant challenges in energy, the environment, and security. Efforts to leave future generations a world that is safer, cleaner, and more prosperous must determine now how to provide energy while reducing contributions to and mitigating the effects of climate change.

Climate Change and Energy

Globally, fossil fuels account for 63 percent of electricity generation and 84 percent of primary energy consumption (BP 2020), negatively impacting human health and safety. In 2016 household and ambient air pollution together accounted for approximately 7 million deaths, or about 13 percent of mortality, around the world (WHO 2020). Yet the use of fossil fuels is growing, even as 13 percent of the global population—nearly 1 billion people—have no access to electricity (World Bank 2020).

Fossil fuels also contribute substantially to climate change (USGCRP 2018), which is likely associated with risks of increasingly intense storms as well as drought, wildfires, and rising sea levels (Emanuel 2007; Hsiang et al. 2014). In addition, a 2018 World Bank report projects that, on the current path of global warming, over 143 million people around the world could be compelled to migrate within their countries by 2050 (Rigaud et al. 2018). And in 2018 the US government’s Fourth National Climate Assessment estimated that climate change could cost this country hundreds of billions of dollars annually by the end of the century (USGCRP 2018).

Fortunately, there is growing interest in a decarbonized energy system, and awareness is expanding to people who make policy and technology decisions in the United States and throughout the world. The International Energy Agency (IEA 2020) reports generally accelerating growth in government investments in energy research and development, particularly in low-carbon energy, over the past several years.

The IEA contends that, by investing deliberately in energy innovation, countries have an opportunity to “stimulate economic recovery and help reshape the energy system to be more sustainable and resilient in the longer term” (Gül et al. 2020). And in its Sustainable Development Scenario,[1] the IEA found that technologies currently at the stage of large prototype or demonstration account for about 35 percent of needed cumulative emission reductions (Gül et al. 2020).

These findings and circumstances underscore the importance of broadly investing in advanced energy R&D, in particular the potential role of nuclear as a cost-effective, reliable component of an integrated low-carbon energy system that includes a diverse set of renewable and clean technologies.

In This Issue

The articles in this issue address advances, opportunities, and needs in nuclear energy as well as its role in current and future decarbonization efforts. They highlight research, development, and demonstration tasks pivotal to ensuring that nuclear technology can contribute meaningfully to addressing global energy challenges. They also highlight safety, resilience, and flexibility attributes of advanced nuclear energy systems, and lay out some of the regulatory and investment challenges that must be overcome.

Bruce Hallbert and Kenneth Thomas set the stage by explaining the value of sustaining and extending the operation of the current nuclear fleet based on carbon avoidance and economic impact. They describe various research activities of the US DOE Light Water ­Reactor Sustainability (LWRS) program in predicting and addressing materials degradation, supporting the implementation of digital instrumentation and controls, and evaluating and demonstrating advanced applications of nuclear energy, such as hydrogen production.

Karen Dawson, Michael Corradini, John Parsons, and David Petti highlight results from modeling efforts showing the roles of firm, fast-burst, and fuel-saving electricity generation technologies in a decarbonized electricity system. In cost-optimized low-carbon model­ing scenarios, ­nuclear energy deployment generally expands, especially as nuclear energy costs fall.

Charles Forsberg and Shannon Bragg-Sitton demonstrate the importance of addressing electricity and heat consumption to reduce greenhouse gas emissions. The high capital and reduced operating costs of key low-carbon ­energy ­technologies favor baseload operation, which the authors suggest could be enabled by the ability to switch production among electricity, heat, and hydrogen. Integrated energy systems would offer this flexibility and optimization.

Eric Ingersoll, Kirsty Gogan, and Giorgio Locatelli contrast capital costs for nuclear power plants built in Asia and those constructed in the United States and Europe, and review cost drivers that explain the differences. They itemize ways that standardized designs, manufacturing approaches, advanced technologies, and project management and execution practices can ­deliver competitive nuclear capital costs.

Jessica Lovering and Jameson McBride illustrate the trade-off between economies of scale and learning effects by calculating hypothetical break-even deployment points for small and very small reactors. They also suggest policy levers that would enable and encourage learning effects.

José Reyes, Finis Southworth, and Brian Woods describe advanced safety characteristics in next-generation reactors, highlighting the value of those features in enhancing resilience, flexibility, and functionality for new applications.

Richard Meserve reviews regulatory challenges that must be addressed to enable efficient licensing of advanced ­reactors—existing regulations do not neatly apply to the new technologies and designs. Training, testing, and licensing changes are needed in areas as diverse as fuels, siting, containment, and safety systems.


Together, these articles present a strong case for the valuable role of nuclear energy in decarbonization and offer proposed solutions to challenges. They catalogue some of the progress that has been made with existing technology while focusing on the promise and possibility of nuclear energy and its advanced applications. The overarching message is that nuclear is a critical and reliable component, complementing other low-emission resources, of the nation’s sustainable energy network.


BP. 2020. BP Statistical Review of World Energy. London.

Emanuel K. 2007. Environmental factors affecting tropical cyclone power dissipation. Journal of Climate 20(22):5497–509.

Gül T, Fernandez Pales A, Bennett S. 2020. IEA Special Report on Clean Energy Innovation highlights the need for countries to work together to accelerate technology progress. Mission Innovation, Jul 8.

Hsiang S, Kopp R, Jina A, Delgado M, Rising J, Mohan S, Muir-Wood R, Rasmussen DJ, Mastrandrea M, Wilson P, and 2 others. 2014. American Climate Prospectus: Economic Risks in the United States. New York: Rhodium Group.

IEA [International Energy Agency]. 2020. World Energy Investment 2020. Paris.

USGCRP [US Global Change Research Program]. 2018. Fourth National Climate Assessment, Vol II: Impacts, Risks, and Adaptation in the United States. Washington.

WHO [World Health Organization] 2020. Global Health Observatory Data. Geneva. Available at .

World Bank. 2020. World Development Indicators. ­Washington.


[1] development-scenario

About the Author:Ashley Finan is director of the National Reactor Innovation Center at Idaho National Laboratory.