There are currently 104 nuclear reactors operating in the U.S. That may sound like a lot, but combined they contribute to barely 10 percent of our total energy output, which is largely dominated by coal and other fossil fuels. Furthermore, no new reactors have been built during the last decade and many of our current reactors are reaching the end of their lifespan. Consequently, if no new reactors are built, our nation will become even more reliant on the increasingly inviable option of fossil fuel-burning plants to meet its energy needs. Most "clean" energy sources, such as solar and wind power, are too inefficient to be a practical replacement for fossil fuel burning plants, although they can help ease the nation's power strains. Other alternative energy sources, such as hydrogen power, are too underdeveloped to be a practical solution to our nations imminent, wide scale energy needs. Nuclear power, however, does offer a potential solution.
Nuclear power has enormous potential. It can efficiently produce large amounts of energy. It produces no environmentally damaging emissions as a by-product. However, nuclear power does have three major drawbacks: The nuclear materials themselves are inherently dangerous and can be used in weapons, the leftover waste products of nuclear reactions are dangerously radioactive and must be isolated for thousands of years and there is not enough cheap fissionable uranium in the world to power a large number of thermal reactors for an extended period of time. Despite these three main problems, the re-emergence of an old technology could make nuclear power an effective, safe and clean power source for the U.S. as it shifts from fossil fuels to cleaner alternatives.
This technology is called a fast-neutron reactor. All of the current nuclear power plants in the U.S. are thermal reactors that use a chain reaction involving uranium to produce heat, which creates steam to drive a turbine, producing power. These reactors only harness about five percent of the energy originally present in the uranium, while the other 95 percent is left wasted and unused in the form of nuclear waste, which then must be isolated. However, if the waste uranium and plutonium products are refined using pyrometallurgical recycling, a process that recovers 99 percent of the fissionable products from thermal reactor waste, a fast-neutron reactor can then completely convert the remaining uranium and plutonium into energy. Instead of only harnessing five percent of the energy originally present in the uranium, over 99 percent of the energy is harnessed. By combining thermal reactors with on-site pyrometallurgical recycling and fast-neutron reactors, many of the drawbacks of traditional thermal reactors can be avoided.
The first major drawback of nuclear power is safety. Traditional thermal reactors produce a mixture of plutonium and uranium as a waste. These waste products must then be transported to either be refined for use in other thermal reactors or to a site such as the Yucca Mountain to be isolated until they become safe. A common fear is that while in transit, the plutonium will be stolen to be used in nuclear weapons. However, since fast reactors use this plutonium up, they eliminate the risk of plutonium leftovers being used in weapons. Furthermore, technological advances such as pebble bed reactors have made nuclear reactors, for all intents and purposes, completely safe. Consequently, thermal reactors coupled with fast-neutron reactors pose no realistic safety issues.
The second major drawback of nuclear power is waste. Traditional thermal reactors produce radioactive wastes that must be isolated for tens of thousands of years. However, if thermal reactors were to be coupled with fast-neutron reactors, their waste products would only need to be isolated for a few hundred years, rather than a few thousand. Moreover, since 99 percent, as opposed to five percent, of the energy present in the fissionable uranium is used, there would be even less waste present in the first place, because most of the material is consumed in the reaction.
The third potential drawback of nuclear power is the lack of enough cheap fissionable uranium to power a large number of thermal reactors for an extended period of time. Despite this potential problem, thermal reactors coupled with fast-neutron reactors are 20 times more efficient than thermal reactors alone. Consequently, the Earth's supplies of cheap fissionable uranium should be more than enough to power a large number of reactors for an extended period of time. And I'm not proposing nuclear power as a permanent solution to our energy needs, but instead as an effective, for the most part clean, and feasible energy source for our nation as it transitions from fossil fuels to alternative energy sources such as fusion (if anyone ever gets it to work) and hydrogen power. Through the combination of thermal reactors and fast-neutron reactors, all of the major drawbacks of thermal reactors alone can be avoided or minimized to a point where they become negligible.
Fossil fuels currently provide around 85 percent of our energy needs; the U.S. needs to begin looking for a power source that can help shoulder the burden. Nuclear power is an extremely viable alternative that should be further developed: the U.S. needs to begin to diversify its energy infrastructure, and right now, thermal reactors coupled with fast-neutron reactors are a very strong option to accomplish such diversification.
Barbieri can be reached at jbarbieri09@amherst.edu