The U.S. Nuclear Regulatory Commission expects to receive 25 licensing applications in the next five years for a new generation of advanced reactors. But getting any of these designs from the drawing board to reality is going to require overcoming a lot of hurdles and uncertainties. Getting any new technology to market is challenging, but that challenge is even more acute for nuclear because of the complexities and costs that it entails.

In this episode we'll look at how two U.S. nuclear projects are navigating a complicated government licensing process to develop a first-of-its-kind technology that could make a pretty big difference in our ability to decarbonize our global energy supply.

People: Dayne Broderson, Alaska Center for Energy and Power; Eric Gerrard and Don Dry, Eielson Power Plant; Tara Neider, SVP and Project Director, TerraPower

Places: Eielson Airforce Base, Fairbanks, Alaska; Kemmerer, Wyoming

Technology/Concepts: Arctic resilience, nuclear navy, nuclear rennaisance, natrium reactor

Closing the Gap is hosted by Gwen Holdmann and produced by Jennifer Pemberton. Music is from Blue Dot Sessions.

Nuclear power is different from other energy sources. When we talk about new nuclear projects, it can still bring up strong and sometimes emotional reactions for people -- more so than with other sources of energy, and those opinions are much more divided across the political spectrum than any other technology. How did public perception change as nuclear moved from a technology of war to the energy solution of the future? And when it comes to energy technologies, or really any technology, how safe is safe enough?

People: Baruch Fischhoff, Professor of Engineering and Public Policy at Carnegie Mellon University; Diane Hirschberg, Director, Institute of Social and Economic Research at the University of Alaska Anchorage

Places: Trojan Nuclear Power Plant

Technology/Concepts: Nuclear energy, atoms for peace, acceptable risk, Atomic Energy Commission, Nuclear Regulatory Commission, Project Chariot

If you want to learn more about Project chariot, Alaska author Dan O'Neill tells the whole story in his book The Firecracker Boys. We leaned on Dan's knowledge of this history in this episode, so thank you, Dan.

Closing the Gap is hosted by Gwen Holdmann and produced by Jennifer Pemberton. Music is from Blue Dot Sessions.

Iceland is a powerhouse when it comes to harnessing the heat and the energy that's pouring up through the tectonic crack that runs diagonally across the island. Icelanders originally got the idea for geothermal district heating from turn-of-the-century Idaho. But since then, the small nation managed to gather best practices from places like Boise, and then improve on them. And now they have the most concentrated know-how of geothermal energy in the world, and they market and export that expertise globally.

People: Erlingur "Eli" Gudleifsson, Alaska Center for Energy and Power; Halla Hrund Logadóttir, Director-General of Iceland's National Energy Authority (Orkustofnun)

Places: Boise, Idaho; Reykjavik, Iceland

Technology/Concepts: district heating; geothermal; technology adoption life cycle Closing the Gap is hosted by Gwen Holdmann and produced by Jennifer Pemberton. Music is from Blue Dot Sessions.

Iceland is widely regarded as a global leader in clean energy. Not only is their energy sustainable, it's cheap, too. They have some of the most affordable heat and power in the world. But it was literally one of the poorest countries in Europe two generations ago. So, how did Iceland get here? What would they say are the most important choices and investments they made along the way? They share their secret recipe with us on this episode of Closing the Gap.

People: Halla Hrund Logadóttir, Director-General of Iceland's National Energy Authority (Orkustofnun); Erlingur "Eli" Gudleifsson, Alaska Center for Energy and Power; Alec Mesdag, CEO Alaska Electric Light & Power

Places: Grindavik, Iceland; Reykjavik, Iceland; Juneau, Alaska

Technology/Concepts: Electrification, affordable energy, oil crisis, economies of scale, hydropower Closing the Gap is hosted by Gwen Holdmann and produced by Jennifer Pemberton. Music is from Blue Dot Sessions.

We can start exploring the current energy transition by first stepping back in time to look at the last big one – the one that gave millions of people around the world widespread access to electric power. Rural electrification remains an ongoing process today, particularly in rural and remote areas of the developing world. Getting electricity monumentally changed people's lives. We'll go back to experience that transformation through the words and voices of those that were part of that struggle in rural Alaska.

People: Halla Hrund Logadóttir, Director-General of Iceland's National Energy Authority (Orkustofnun); Willie Iġġiaġruk Hensley, former Alaska lawmaker, architect of the Alaska Native Claims Settlement Act, and original board member of the Alaska Village Electric Cooperative

Places: Reykjavik, Iceland; New Stuyahok, Alaska

Technology/Concepts: Rural electrification Closing the Gap is hosted by Gwen Holdmann and produced by Jennifer Pemberton. Music is from Blue Dot Sessions.

I'm Gwen Holdmann, an energy researcher in Alaska. This podcast is where I share stories from the people I've met and the places I've visited around the world that are at the leading edge of the global energy transition: Geothermal beaches in Iceland, hydrogen-fueled tiki torches in Hawaii, solar-powered villages above the Arctic Circle, and power plants that are capturing their own greenhouse gas emissions and turning them into stone underground.