I take an engineering course offered by an academy in my school district. It isn't a terrible course by any means, but some days, there is an excess of time in our weekly schedules that my teacher scrambles to fill. One such attempt was to assign us to research and create an engaging presentation on a clean source of energy. By some unfortunate fate I was placed in a group that already existed and was presenting on hydropower, but many students were like me a few years ago in my English class, and chose to present the "cool" option: nuclear energy.
Among the first to present in nuclear energy were unsurprisingly nitpicked and left to fend for themselves against the many questioning hands raised as soon as the presentation ended. The topic of nuclear waste was brought up, to which the presenter addressed that nuclear waste can be safely stored in containers deep underground. But, that didn't seem to satisfy the masses, and it didn't satisfy me either. Perhaps it was the negligence of the crucial detail that the entirety of the United States' nuclear waste since it first became an industry could fit into a singular football field, but how was anyone supposed to know that? No one makes that obvious when writing Wikipedia entries or Britannica articles about nuclear energy.
As the presentations continued, one irked me in particular. It was a presentation titled "Nuclear Fusion," except all the information in the slideshow was about nuclear fission. If we want to build a world that supports nuclear energy, we need to build a world that understands it first. The first steps to understanding how nuclear energy can help us is by discussing what kinds of nuclear energy there are.
There are two main forms of nuclear energy, and currently, only one is deployed on a grand scale. It is reliable, efficient, and cost effective, but those are often the last things you hear about them when discussed in the media. This form of nuclear energy is called nuclear fission. It earns its name by the energy produced during a reaction called fission. The way fission works can be visualized by the popular mousetrap video that went around a few years back. A man sets up an entire enclosure filled with mousetraps, edge to edge and all loaded with ping pong balls on the trigger. The man dumps a singular ping pong ball onto the mousetrap-ified ground, and what happens next is pure chaos.
A singular mousetrap is triggered by the one ping pong ball, and it as well as its own ping pong ball flies into the air under its own snapping force, triggering another mousetrap, and then another, and then another. We can think of fission in terms of mousetraps and ping pong balls too, as fission is simply a compounded chain reaction. Like mousetraps with ping pong balls, atoms are comprised of a nucleus (mousetrap) and electrons (ping pong ball). When one singular electron is fired towards an atom, it causes the atom to split, firing off its own electrons that then collide and cleave through its neighboring atoms. Before long, you have massive amounts of energy produced by this reaction, but how exactly does harvesting it work?
This is where the genius mechanism of a nuclear fission reactor comes into play. The nuclear fission is contained within a reactor that has rods of Uranium-235 inside. This Uranium isotope in particular is used because of its radioactivity. When things are radioactive, they shed their electrons, and when something sheds its electrons a lot, those electrons can start a fission reaction by splitting apart a nearby atom. This fission then heats the water surrounding the uranium rods, creating a high pressure steam that spins electricity-generating turbines. To control this fission reaction, we use lead rods that intercept the reaction since lead has a high density, and it's atoms can't be broken apart as easy. These are called control rods, and they can be raised or lowered depending on what you need the fission reaction to do. If the reactions needs to be increased, the control rods are raised out of the way so that the uranium can interact with itself. Witnessing this process is truly other-worldly for the fact that the nuclear fission we use for energy produces a bright, mystical blue glow called Cherenkov Radiation.
Once the fuel rods have been depleted and can no longer engage in the necessary amounts of fission, they are replaced, and reserved as waste. Or, alternatively, they can be recycled and replenished to be used again, which many countries already do.
Nuclear currently accounts for only 18.2% of the United States' power source, and only around 10% of the globe's. With the climate becoming increasingly more unpredictable, global warming has taken a forefront in many people's minds. To curb global warming and meet energy demands other clean energy sources like wind and solar cannot feasibly meet, these percentages of nuclear power need to grow. But in some places, it only seems like these numbers are shrinking. As of 2013, six of the United States' reactors have closed, and an additional eight are in the process of being decommissioned. This is at the responsibility of anti-nuclear sentiment that isn't even confined to just the western half of the globe. News of Japan releasing wastewater into the ocean has sparked deep controversy all over the world, and many people's initial reaction is a disdain for nuclear power without knowing the facts. It's difficult to convince the masses that careful examination has proved the waste water to be safe, that even if you swam in the water, you would be entirely unscathed and not irradiated. However, that creates a responsibility for experts and advocates to tear down the stigma of nuclear energy in order to improve policy and public opinion of nuclear power. Despite this responsibility, it also creates an opportunity.
Nuclear fusion has been tossed around and entertained as theory for years, but just recently have we been able to envision it as a reality. Nuclear fusion is like the antithesis to fission. Instead of breaking apart atoms, they're fused together, creating massive amounts of energy. If nuclear fission wasn't already one of the safest sources of power, nuclear fusion eliminates all of the classic risks many people fear when they envision nuclear fusion.
Upon disasters, the reactor is simply shut down. If it's damaged, fusion simply stops working. Depending on the type of failure, the plant might simply be ruined in a way that would require the inner core to be removed and replaced. It would not leak any radiation, and of course, it cannot explode.
Instead of using uranium or plutonium, fusion uses a source called Deuterium, or a stable hydrogen isotope that has an extra neutron. When fired at high temperatures and high speeds at Tritium, a hydrogen atom with two additional neutrons, it fuses with the Deuterium to release massive amounts of energy. This reaction takes place inside the fusion reactor of course, a large, donut shaped vacuum chamber that utilizes magnetic coils to create conditions for the plasma inside the chamber for fusion to happen. Once fusion occurs, a process similar to fission happens where the reaction superheats water to create high velocity steam that generates power by passing through turbines.
So far, we know that fusion is possible, and we have achieved it. However, we haven't found a way to achieve a net energy positive. Running a reactor that is more technically complicated than a fission reactor takes a lot of power and energy. Compared to the amount of energy we're able to extract from the fusion reaction, it isn't sustainable as an energy source quite yet.
That doesn't mean fusion is out of the question though. In fact, quite the opposite. Such a challenge has been undertaken by hundreds of experts and researchers in hopes of making a breakthrough. ITER is the world's largest fusion project, comprised of five different nations to create the tokamak reactor. Many countries, including the U.S., have their own fusion experiments and research dedicated to finding a way to achieve a net energy positive. If viable fusion energy is achieved, it will be the world's cleanest, most efficient power source with no greenhouse gas emissions, and no waste that can contaminate materials. It will be up to four million times more efficient than current fossil fuel sources. With that kind of efficiency, the cost put into production of the reactor will easily be negated by its high energy output.
Currently as it stands, fission is the best step forward in preserving our climate with low-emission and efficient energy while still meeting power demands. The only reason it hasn't been implemented yet is because people simply don't know enough about it, or buy into the negative stigma created by sensationalized disasters.
You can help fight this stigma through many ways, one of which by becoming a member of ANS, which is free of charge to students, and help connect you to others interested in nuclear energy. Additionally, you can write a letter to your State Representative and ask them to review nuclear energy policy in the state, and perhaps to even expand it. Ask friends and coworkers their thoughts on nuclear energy, and use it as an opportunity to share its potential. No matter how small the efforts are, every bit of it counts towards changing the world for the better.