The topic of nuclear power always comes up when I talk to people about climate change. It is a very polarizing issue indeed, with two primary camps drawing most of the attention. There are the maximalists who desire to see a great deal of new nuclear infrastructure put in place to do the heavy lift of the energy transition, who are countered by those who would see all reactors taken offline as soon as possible. Though nominally on the same side vis-à-vis taking action on climate change, I have often seen this argument become the source of irreconcilable differences and a breakdown in cooperation. But, ignoring that dilemma, what is the proper role of this energy source? My views haven't changed since publishing my book last spring, so the following excerpt provides a good summary for how I think we should be using our nuclear resources.
Nuclear energy has very similar qualities to fossil fuels. The internals of the power plant are conceptually the same: a heat source boils water to produce steam to turn a turbine and generate electricity. That heat source is also dependent on a finite fuel, currently uranium, mined from within the Earth. Since those reserves will eventually be depleted, the same reasoning precluding fossil fuel use applies to proliferating nuclear power as well.
That is, in many respects, unfortunate. Nuclear energy is carbon neutral since it doesn’t eject carbon dioxide into the atmosphere as it generates electricity. It is also incredibly energy dense, capable of outputting tremendous amounts of power from individual facilities. Those two factors mean nuclear sources will have to be part of our energy mix for the time being, even if we don’t build any new ones. The United States generates about a fifth of its yearly energy from nuclear reactors. Shutting them down would require replacement power sources to compensate for that change instead of decommissioning fossil fuels. Doing so only makes our job more difficult and would unnecessarily delay the transition.
Germany and Japan offer examples of what to avoid. Both countries started mothballing their infrastructure after the reactor meltdowns at the Fukushima nuclear facility in 2011. Japan previously generated about 30 percent of its electricity from nuclear power before that incident, and replacing it required increased gas and coal consumption. Germany took a similar path and has replaced some of its nuclear capacity with coal. Even with government policy favoring renewables, the wake left behind by the nuclear shutdown has largely preserved the old fossil fuel baseload. Thus, our objective is clear: keep our nuclear sources running for as long and efficiently as possible to speed the transition.
The United States’ nuclear fleet is not very efficient from a fuel standpoint. Only a fraction of its potential energy is extracted before it has to be taken out and replaced with fresh uranium. The old material is ultimately consigned to nuclear waste storage, but it could be put to better use through recycling. France is able to get 70 percent of its electricity from nuclear plants because their spent fuel is reprocessed and reused in reactors, drastically cutting down the need to mine and refine additional material. Nothing is preventing us from doing the same thing, only a Carter-era ban on the practice. Reversing that policy and building reprocessing capabilities would be a relatively easy way to keep using nuclear power for the time being while not spending additional resources on mining and extracting raw materials while simultaneously helping keep down the level of nuclear waste we have on hand.
Building new nuclear reactors would mean more nuclear waste. Dealing with it is another global-scale challenge, just not so acute as climate change. The 80,000 tons the United States has produced will continue emitting dangerous levels of radiation for ten thousand years. Fighting climate change by building more traditional reactors would only increase the scale of that problem. Fortunately, some alternatives could solve both problems at once. Breeder reactors, for example, are capable of using a wider variety of fuels, including some existing nuclear waste. They also break down the fuel into products that are dangerous for much shorter periods of time, decades instead of millennia. Unfortunately, none of those options are quite ready, running afoul of our requirement that we only use proven technology.
The conclusion is we won’t be building more nuclear power, at least for the time being. Even though nuclear energy is not fundamentally sustainable, it could be capable of providing a great deal of carbon neutral power that helps us get over the hump of our grid transition. We may need to replace newly developed reactors in a hundred years, but it is a small price for bending our rule to only use permanent solutions. Until those better technologies are fully proven, our existing nuclear facilities will continue operation and provide carbon-free electricity to the grid during our transition, and we’ll reprocess our spent fuel to prolong their operation. Therefore, the rest of our new grid will need to be built using the other carbon neutral options available to us: renewables.
 Depending on the technology, we may have several centuries worth of nuclear fuel reserves.
 USEIA, “What is the Status,” updated April 15, 2020.
 USEIA, “What is U.S. Electricity,” updated February 27,2020.
 World Nuclear Association, “Nuclear Power in Japan,” updated March 2020; Buchholz, “How Fukushima Changed,” March 10, 2020; Rooney, “Eight Years after Fukushima,” December 11, 2019; IEA, “Japan,” accessed August 28, 2020; McCurry, “JapanShould Scrap,” September 12, 2019.
 Oberhaus, “Germany Rejected Nuclear Power,” January 23, 2020.
 Appunn, Haas, and Wettengel, “Germany’s Energy Consumption,” August 21, 2020.
 Planete Energies, “France’s Overall Energy Mix,” August 27, 2018; Krikorian, “France’s Efficiency,” September 4, 2019.
 The stated reason was to prevent the nuclear proliferation. Andrews, “Nuclear Fuel Reprocessing,” March 27, 2008, 3.
 USGAO, “Disposal of High-Level Nuclear Waste,” accessed August 1, 2020.
 For more information, see: Martin, Super Fuel.