There are other sources of energy production that provide our power grids with a baseline, one of which has great electric potential — nuclear energy.

“There’s two types of nuclear energy: nuclear fission and nuclear fusion,” said Gregory Maxwell, associate professor of mechanical engineering and adviser of Iowa State’s American Nuclear Society. “Fission is taking heavy atoms and splitting them, and in that process energy is released. Fusion is taking two lighter atoms and putting them together, and that also releases energy.”

The difference between nuclear and coal-fired energy would be the fuel, said Brendan Ward, senior in mechanical engineering and president of the ISU American Nuclear Society.

“The difference between wind or solar would be that, like coal, you can base-load the grid with power, whereas wind and solar, they can’t provide the grid with a stable source of power,” Ward said.

Similar to a coal-fired power plant, which uses a boiler to generate electricity, nuclear power plants use a nuclear reactor.

The fission process produces heat, and ultimately you want to transfer that heat to make electricity out of it, Maxwell said.

“The most common way to [generate electricity] is to transfer heat out of water and then boil the water to make steam,” Maxwell said. “The steam is then used in a steam turbine, which produces mechanical work, which drives an electric generator to make electricity.”

Uranium, the mineral used to fuel nuclear reactors, is extracted the same way oil and coal are extracted.

“Uranium is a mineral; it’s like iron-ore. You dig it up and then you need to separate the material that you’re interested in, the uranium, from the dirt and from other elements that are in the dirt,” Maxwell said.

“In the United States, they’re doing an in-situ uranium-mining process, where you drill a hole and inject high-pressure water into the hole, and the water then leeches out the uranium from the well, so you don’t have the scarring of the land or the moving of topsoil to get at the uranium.”

Like oil, uranium has to be refined. From there, the element is converted into what’s known as yellow-cake uranium, otherwise known as uranium oxide.

Once the uranium is refined, it’s converted from a gas back into another compound — uranium dioxide — which is the ceramic or powder. They take it and compress it into pellets, Maxwell said.

These pellets are then stacked on top of other pellets inside 12-foot-long rods made of zirconium, which is called a fuel assembly. The fuel assembly would load the pellets into the nuclear reactor, where a nuclear reaction would take place.

“That fuel stays in the reactor for about three to five years, but every 15 to 18 months, a nuclear power plant will shut down for a fuel outage; and in a fuel outage, what they do is replace about one-third of the fuel with fresh fuel, and they reshuffle the fuel that’s in the reactor core to better optimize the utilization of the fuel,” Maxwell said.

The direct waste product from a nuclear reactor is highly radioactive, so it is immediately submerged under water because of the significant amount of heat it generates.

Spent nuclear fuel generates a lot of heat, enough that if you don’t keep it cool, it will melt, Maxwell said.

“Spent fuel comes out of the reactor underwater and then it goes to another building to the reactor site where it’s kept in a big swimming pool, a spent fuel pool,” he said. “There it just sits; it glows blue because of the radiation it gets off.”

Nuclear plants store their spent fuel into large concrete casks. Located somewhere secure within the plant, the waste sits until the plant decides what to do to further dispose of the waste.

The radioactive elements that come out of the reactor have a property called “half life,” said Alex Koth, senior in mechanical engineering and chairman of programming for the ISU American Nuclear Society.

“Half life relates to how much of that element is radioactive, and the half life pertains to how long it will take for that particular element to be half as radioactive as it is right now,” Koth said.

But one attribute that ISU’s American Nuclear Society stresses is the potential to reuse the spent fuel produced from nuclear reactors.

“What comes out of the reactor is mostly unburned fuel,” Ward said. “You have about 5 percent of that which is fissioned; 90 to 95 percent of that is still usable in some shape or form.”

The United States currently does not reprocess the waste material produced from nuclear reactors.

Reprocessing spent fuels does multiple things — it means less uranium that needs to be dug out of the earth, and it means a reduced volume of waste material.

“The material that you’re left with after you reprocess has a much shorter half life than the stuff you were just going to bury,” Maxwell said. “You’ve reduced the volume, you’ve reduced the toxicity, you’ve reduced the need for the raw material for the mining in the first place.”

There are currently 104 nuclear power plants operating in the United States, with plans to build new plants and phase out old plants. About 20 percent of the electricity generated in the U.S. is from nuclear energy.

Iowa State’s American Nuclear Society strives to advocate the potential of nuclear energy, bringing in various guest speakers to their meetings and taking trips to nuclear power plants.

“Mostly we get professional speakers to come in and speak about what nuclear science means in the real professional atmosphere,” Koth said. “Students have this hunger for knowledge of the subject, and getting the professional speakers to come and talk about topics that pertain to the professional atmosphere is really the most exciting part.”

The ISU American Nuclear Society was recognized last semester as an active student organization, introducing the nuclear engineering minor into the ISU curriculum.

One focus the organization stresses to emphasize is the immense amount of safety involved in nuclear power plants.

“At a nuclear power plant, there’s so many safety things in place — nuclear regulatory permission has regulations after regulations on what can happen in a power plant, everything goes by a code, everything is safe,” Ward said.

With the group becoming recently active, the ISU American Nuclear Society hopes to reach students outside its department, to further advocate the potentials of nuclear energy.

“The idea is, the more you know about nuclear engineering, the less you’re going to fear about it,” Ward said.