Nuclear energy has long been touted as the ultimate fuel source, limitless and emission-free. However, the term nuclear energy conflates two very different processes and technologies: fission and fusion. For anyone interested in or concerned about the climate, getting acquainted with the facts, pros, cons, and issues surrounding both varieties of nuclear energy is a good idea.
Nuclear energy, the once-promising alternative, emits no greenhouse gases, but it presents a challenge because fission’s fuel is not renewable. Fusion nuclear power may someday have a role in a post-fossil fuel world, but that day remains decades away. Both nuclear fission and nuclear fusion emit no greenhouse gases, but fission’s fuel is not renewable. In fact, its spent fuel takes thousands of years to lose its lethal radioactivity. Fusion nuclear may someday have a role in a post-fossil fuel world, but that day is also in the distant future.
Nuclear fission is the splitting or breaking apart of the radioactive atomic nuclei of the heavy metal elements Uranium or Plutonium. Allied scientists learned how to split atoms in the secretive Manhattan Project during World War II. Their work culminated in the explosion of nuclear bombs at Hiroshima and Nagasaki in 1945.
Nuclear fission is problematic for several reasons. Although a fission reactor produces no carbon emissions, it produces spent fuel that is radioactive for tens of thousands of years with radiation that is deadly to humans. While the engineering problem isn’t quite of the same order of difficulty as creating a sun on Earth, ensuring the safe storage of the radioactive waste for millennia is not a trivial problem. It has yet to be solved. Nobody wants it anywhere near them, for understandable reasons. The problem has its own acronym, NIMBY, which stands for ‘Not In My Back Yard.’
The nuclear fission plants built in the 1950s and 1960s produced quite a bit of waste. Some is stored in caves, some deep underground. Some has been lost — nobody knows for sure where or how it’s stored. And we are 100 years into a multi-millennial disposal cycle. Germany wants to close all its fission realtors from the 1960s, but it has nowhere to stash the spent but still radioactive fuel rods. Nobody wants them, including Germans.
Nuclear diehards have designed new, small, fail-safe reactors that generate far less waste than old designs. However, fans of fission haven’t been able to solve the problems of how and where to store fission’s radioactive wastes for thousands of years. Nor have they resolved how to avoid the regulatory hurdles fission must pass to be licensed and the insurance costs for protecting against a Chernobyl-like disaster. While energy produced by nuclear fission is quite cheap, the design, licensing, insurance, construction, and operating costs simply make it uneconomical given current alternatives.
Furthermore, everyone is aware of the nuclear accidents that have befallen supposedly fail-safe plants: Three Mile Island, Chernobyl, Daiichi Fujiyama. Lessons have been learned, and today’s designers assure us that the new designs cooled by liquid sodium won’t evaporate causing a meltdown if power to the cooling system were to be interrupted. Still, would you want one located near your home?
Design of nuclear fission reactors has improved a great deal since the last generation of reactors, both in terms of fuel efficiency and safety. Today’s designs produce much less spent fuel than those built decades ago, although the waste disposal problem has not been eliminated.
Bill Gates, the multi-billionaire founder of Microsoft, has invested heavily in the start-up nuclear fission company Terra Power. He sees his company providing significant quantities of the carbon emission-free energy the world will need in 2050. Gates sees reaching zero emissions as the way to overcome the climate crisis, and he presumes that technology will take us there. Technology can generate energy that doesn’t heat and befoul the climate, and there’s a reasonable expectation that technology can and will be developed to capture carbon dioxide directly from the air and perhaps even from the oceans.
However, Bill Gates is only partially right. Other essential components of a climate solution depend on changes that humans make in the way we live, eat, work, play, and relate to other humans and the environment. None of these changes is especially difficult in and of itself, but collectively, they may be beyond humans’ vaunted adaptability.
The second process for creating energy from nuclear reactions is fusion, the merging of two hydrogen atoms into one helium atom. This is the same process that occurs within our sun and all other stars. Both splitting and fusing atoms require — and release — great quantities of energy. Nuclear scientists from several countries are working hard to achieve a fusion reaction that produces more energy than it takes to make it happen, the equivalent of creating a mini-sun on Earth.
Nuclear fusion doesn’t have fission’s waste disposal problems, but it does share all its other negatives. Operational nuclear fusion, despite recent design advances, is still a decade or two away. By then the world will run on wind, solar, and hydrogen. Fusion will always be an expensive niche energy provider.
However, despite decades of work and billions of dollars invested in the goal, no viable fusion reactor yet exists. Given enough time, money, and human ingenuity, one day nuclear fusion will power a significant percentage of the world’s energy. But that day is distant. One crystal-baller saw fusion playing an important role in 2100 if the human race met the challenge of preserving a livable Earth past 2050.
So ClimateYou believes that neither nuclear fission nor fusion will become our civilization’s dominant form of energy. Abundant nuclear energy may facilitate the long-term survival of the human race, but it will be far from the only, or even the most important, determinant of our future.