Everyone who has played video games – or perhaps lived with someone who plays – is familiar with cheat codes. With cheat codes, a player can get disproportionate advantage over the other players, or perhaps finishing the game becomes much easier.
In our own ”Civilization” game, humanity has learned to utilize ever higher quality and more energy dense energy sources. These have increased our productivity and standard of living at an unprecedented rate. In Europe, coal started replacing firewood in the 17th and 18th centuries. And while coal is still widely used in many countries, we have also shifted to oil, LPG (liquefied petroleum gas), and natural gas. All of these are cleaner, denser fuels that have more potential use cases than coal or firewood.
Small steps in the big picture
The steps we have taken have been somewhat small. Coal is perhaps twice as energy dense as firewood, and oil is only slightly more so than good quality coal. But taking small steps can add up to large differences in the big picture over time. Just like upgrading from a wooden sword to a stone sword, then to an iron sword and then to a diamond sword in the popular game Minecraft. Each step brings a small advantage, but they add up.
In the centuries of industrialization, we have gained perhaps a ten-fold increase in the energy density and overall quality of our fuels. Energy density can be volumetric or gravimetric, and the measured density can vary greatly. Gaseous fuels are energy dense gravimetrically, but not volumetrically, as gases take a lot of space for their weight. Fuelwood, coal or peat quality is greatly affected by their moisture, as moist wood is much heavier and releases less energy than dry fuelwood when burned.
These fuels are based on chemical energy released through combustion. This also releases both carbon dioxide, a greenhouse gas, and hazardous particulate pollution. The higher quality the fuel, the less CO2 and pollution is released per energy produced.
Uranium fuel – energy density on another Level
In the case of uranium fuel, it is not a chemical reaction that produces the energy. Rather, the energy is released when the nuclear forces holding the large atom together are broken. This is called fission. When this happens, a small portion of the mass of the atom is turned into energy, mostly heat. In the sun, the opposite happens as two small hydrogen atoms are merged under immense pressure and heat in a fusion reaction, which also releases energy. No greenhouse gases or air pollution is released in nuclear reactions.
The cheat code embedded in nuclear fuel would allow us to live good, high-energy lives with minimal environmental impact.
What makes uranium a cheat code of the universe is its unparalleled energy density. Uranium contains in the order of two million times more energy that can be released than the best chemical fuels do. And there is nothing in between. Looked through the lenses of historical development, we first take small, incremental steps by moving from one chemical fuel to the next and then, suddenly BAM! We leap to a fuel million times denser than the previous one, which produces no greenhouse gases.
Drive further, cheaper and greener with nuclear powered cars
Even though the current fleet of nuclear reactors use only about one percent of the energy contained in the uranium, the result is still spectacular. Let us take electric vehicles (EVs) as an example. It takes roughly 20 kilowatt hours (kWh) to drive 100 km with an electric car, depending on car, climate and driving habits. Same amount of electricity is consumed in a family sauna evening, where the stove (10 kW) can be on for 2 hours. The total cost of this might be around 3 euros/USD, if electricity, taxes, and grid fees are roughly 15 cents per kWh. In Europe, where gasoline is relatively expensive, one might drive for 30 km (approximately 20 miles) for that money.
If one drives around 20,000 km (12,500 miles) per year, an electric vehicle will consume 4,000 kWh of electricity. This can be produced with one tiny uranium fuel pellet in a modern reactor. Depending on the reactor and the size of the fuel pellets it uses, the electricity one gets from a pellet varies between 2,000 and 5,000 kWh. So one uses one pellet, the size of a small candy, for one year of EV driving. Alternatively, one can use roughly 1.5 cubic meters (53 cubic feet) of gasoline with a gasoline powered car to drive the distance. Similarly, one fuel pellet can heat a family home for a year, either with district heating or by using a heat pump.
There has recently been a lot of discussion about the Tesla “million-mile battery” (million miles is about 1.6 million km). This means that the battery could last for a million miles without too much degradation in the cells. If one full charge would power the car for roughly 500 km (approximately 300 miles), the million-mile battery would last for around 3,200 full charging cycles. Such a battery would last 50 years of driving at 32,000 km (20,000 miles) per year, with the bold assumption that the rest of the car around the battery would also last that long.
How much energy would it take to drive the million miles the battery lasts? It would take roughly 320 megawatt hours (320 000 kWh), or almost four years of non-stop sauna. In a modern nuclear reactor, producing this would take around 80 fuel pellets. Not many of us drive that much in a year, so we might use perhaps half of that, a handful of fuel pellets, for a lifetime of EV driving.
A single fuel pellet might be enough
In the future, we will move gradually to next generation technology called breeder reactors. They can utilize the nuclear energy in uranium (or thorium) much more fully than the current generation of reactors. This will allow us to make another giant leap in our energy density journey. A single fuel pellet can then produce a lifetime of EV driving. Other energy use, from electricity to heating and other services, would use a couple more pellets. The spent fuel from these pellets would be only a handful, fitting into one’s pocket. These breeder reactors can also use the spent fuel from current generation of reactors as their fuel source, so uranium is not used wastefully even in current reactors.
The implications of this cheat code that using uranium and nuclear energy gives us are immense. Energy is behind most of the products and services that enable our high living standards. The cheat code embedded in nuclear fuel would allow us to live good, high-energy lives with minimal environmental impact from energy production, and enable high rates of energy intensive recycling for our material needs. Instead of releasing hundreds of tons of CO2 emissions and small particulate pollution through our lifetimes, the waste from producing our energy with nuclear reactors could fit in our coffin with us when it is all over.
Of course, it would be prudent to store the waste products in a suitable pool of water to cool down safely, maybe in a dry cask canister after that and perhaps eventually put the waste into a final repository for long term storage. Even this is relatively easy to do, as there is so little of the waste product thanks to the cheat code.