As an engineer, I have worked and studied in the fields of oil & gas and nuclear energies. The topic of energy has always been dear to me, growing up in the oil town of Houston, Texas. It’s the chemical energy in the food we eat that lets us live; it’s the energy in the gasoline that makes our cars move; it’s the energy produced by power plants that keeps the lights on at home and at the factories. Energy gives us the ability to make the world a better place and aid our fellow man, but it also has the potential for disastrous consequences. The major questions I hear about nuclear energy are: “Is nuclear energy safe? Will the radiation hurt me?” or “I’ve heard nuclear energy doesn’t have emissions, but is it actually clean?” or “Uranium isn’t renewable, is nuclear energy a viable long-term option over oil?” I will attempt to answer these three questions at a very high level for you today, so that you can be better informed in what energy policies you support.
An important fact that most people do not know: every moment of every day you are receiving radiation (or “being irradiated”). This everyday radiation is known as “background radiation” and is harmless. Radiation is measured in “rem” or “Sv” and we receive in the US on average about 300 mrem (3 mSv) per year. High levels of radiation are linked with an increased risk of cancer, but the increase in risk of cancer for 10 rem/yr is 1 in 1,000,000, and there are some places in Brazil and France where the background radiation is above 10 rem/yr(1). The point I want you to understand is that not all levels of radiation are dangerous, but getting massive doses of radiation—like the people who responded to the Chernobyl disaster did—is dangerous.
The worst nuclear energy disaster was Chernobyl. The effects of it are still devastating for the immediately surrounding area. But are nuclear reactors any safer now? Yes, they are. The Chernobyl reactor was designed to produce more power the hotter the reactor got—this led to an uncontrolled reaction which the reactor could not handle leading to a major meltdown and release of
The previous table got at one measure of cleanness—the life-ending effect of a bad environment—but that is not the only measure. Most people are used to comparing carbon emissions. When a nuclear plant is running, it does not produce any emissions to the environment at all by the nuclear process. All of the by-products of the nuclear process are contained within the fuel that is in the reactor. But there are environmental costs to building the large nuclear plant. After including construction costs, wind energy and nuclear energy have the smallest carbon footprints with only 15 grams of CO2 emitted per kWh of energy, which is 1.7% of coal’s 900 g/kWh. One of the complaints about nuclear energy is that it has a nuclear waste problem. I ask: what is the problem? Who is having their health hurt by the spent fuel? Who is getting lung cancer from the emissions and dying? No one. People also say “But Uranium and other materials have such a long half-life, they will be around for billions of years before they are gone!” as if that is a bad thing. What they have really said is that the nuclear waste gets less and less toxic over time, whereas other wastes from other industries are stable and do not become less hazardous. Nuclear waste is one of the few wastes that gets less dangerous over time. I’d also like to bring up that the reason nuclear waste is dangerous is because it is so concentrated: instead of spewing the waste into the atmosphere, it is all stored within the fuel rods and kept on site or at a geological repository. The nuclear process produces so much less waste than fossil fuels because uranium has so much more energy within it than any chemical process. To illustrate this I have included a comic from (4):
Currently we mine uranium ore to power our reactors. It is estimated that this should last us over a hundred years, but clearly, that is not sustainable. However, there are two additional major sources of nuclear energy not being utilized: breeder reactors and uranium in seawater. Breeder reactors use a quirk of the nuclear process to make more nuclear fuel than they consume! Breeder reactors “breed” fuel by turning U-235 (the typical fuel) into energy and neutrons (and fission products), which then go on to turn U-238 into Pu-239 which is also a fuel. By the end of the reactor’s life, there is more energy in the Pu-239 than there was at the start in the U-235. However, to get the Pu-239, a complicated reprocessing procedure is required, which was made illegal. Reprocessing would also reduce the radioactive content of the existing spent fuel to lower levels. The other source of uranium is from seawater. Uranium is naturally occurring in seawater, just like it is naturally occurring in soil. Some processes have been developed which would open up a new and larger source of uranium than we have ever had on land(5).
Nuclear energy is safe, clean, and sustainable as long as the appropriate technology is applied. The energy that we get from the nuclear process can be used reliably to power our world and improve the lives of everyone in it without forcing someone else to deal with our emissions. Fear of the unknown has led to major political setbacks for nuclear energy, but we can educate people in order to promote the use of this good fuel.