Comment: I am assuming that the readers of this website are busy doctors with minimal time for reading that is not work-related. After all, our breast cancer world is changing not every year but almost every week or month. Most of us are breast surgeons required to know how to apply our craft and learn about the advances in other specialists diagnosing and treating breast cancer. I find myself in a unique position of still working but consider myself semi-retired. Not being involved daily in the intensity of clinical practice gives me time to explore other interests, possibly more time than you have because of your busy practice life. I recently read a book published in February 2021 by Bill Gates called “How To Avoid A Climate Disaster.” I can tell you now that this book was not a feel-good read. Like virtually all scientists in the field, Bill Gates believes that we need to get to zero carbon emissions by the year 2050. Bill Gates is confident that we can get there, but after reading his book, I am not as sure.
Nonetheless, virtually all scientists agree that nuclear energy needs to be a part of the equation to approach zero carbon emissions. Fortunately, several advances are occurring in atomic energy generation. I hope in this short blog to outline these advances so that we may all remain relevant in this world of rapid advances in science and technology.
The heart of any nuclear reactor contains a nuclear chain reaction that produces heat through fission. The heat makes steam that spins a turbine which creates electricity. These reactors use uranium for fuel. The uranium processed as small pellets are stacked together and sealed into metal tubes which we have all heard of, called fuel rods. The fuel rods, immersed in water, acts both as a coolant and a moderator to slow down the chain reactions. All commercially online nuclear reactors in the United States are light-water reactors. Light-water reactors use ordinary water instead of heavy water, which substitutes all or part of the hydrogen atom with deuterium.
However, there are now new generation reactors that may debut by 2030. Generation IV reactors are being developed through an international consortium of 14 countries, including the USA. The expectation is that these new generation reactors are cleaner, safer, and more efficient than previous generations. Below is a very brief explanation of what new types of reactors we may see in the future.
Sodium-Cooled Fast Reactors
These reactors use liquid metal (sodium) as a coolant instead of water. These reactors operate at higher temperatures and lower pressures than current generation reactors. These features improve reactor efficiency and safety. Sodium-cooled fast reactors use a fast neutron spectrum, meaning that the neutron can cause fission without being slowed down by the water as they are in current reactors. Also extremely important is that sodium-cooled reactors can use fissile material and fuel from current reactors to produce electricity. One company involved in the sodium-cooled reactors is Terra Power, funded in part by Bill Gates. Home - TerraPower
Very High-Temperature Reactor
These reactors, designed to operate at very high temperatures, produce electricity in a highly efficient manner. In addition, the energy-intensive processes that currently rely on fossil fuels, such as hydrogen production, desalination, ammonium, and ammonia production, could also use this high-temperature gas instead of petroleum products.
Molten Salt Reactor
These reactors use molten fluoride or chloride salt as a coolant. In this case, the salt is dissolved directly into the primary coolant of a standard reactor. The fission that occurs now heats the salt and turns it into a molten state. These reactors are designed to use less fuel and produce shorter-lived radioactive waste. Significantly, molten salt reactors can potentially consume waste, such as plutonium from other reactors.
The move to petroleum-free energy will be difficult. It will not be as simple as a Tesla in every garage. It will require a multi-pronged approach utilizing renewable energy sources as well as nuclear power. However, one proposition that most would agree upon is that prevention of global warming will be substantially easier than mitigation.