Global energy sources are under scrutiny like never before. Climate change and global warming have focused both public and government attention on low-carbon and clean energy.
Renewable energy sources are leading the battle to reduce greenhouse gas emissions. Fossil fuels like oil, coal, and natural gas are singled out as the primary sources of carbon dioxide emissions.
The nuclear industry has been involved in domestic electricity generation since the late 1950s. Nuclear energy’s role has been controversial, yet it endures. In fact, it generates around 20% of the United States’ electricity, according to the U.S. Department of Energy.
Despite nuclear energy’s sometimes polarizing reputation, people love how it transforms our lives. Let’s look at nuclear technology — past, present, and future — and its role on the road to net-zero emissions. And if you’re short on time, check out our introduction to nuclear energy.
What Is the Definition of Nuclear Energy?
There are many types of energy, and nuclear energy is one. We need to get to the building blocks of the universe to begin understanding nuclear energy.
The universe is made of countless atoms. Atoms are made of three particles: protons, neutrons, and electrons. Neutrons have no charge and reside alongside positively charged protons in the nucleus of an atom. Electrons are negatively charged and orbit the nucleus. These three parts are held together in the atom by strong forces; there is a lot of energy stored in an atom’s nucleaus.
The nuclear energy we exploit comes from these atoms. The energy can be released in two ways:
Nuclear fusion: Atoms are fused or combined and form a larger atom. The sun’s core uses nuclear fusion to convert hydrogen into helium, producing energy that, among other things, warms our Earth.
Nuclear fission: Atoms are split to create smaller atoms. This action releases the energy from the atom’s bonds. Humans have built nuclear power plants that harness nuclear fission techniques to produce electricity.
What Does Nuclear Energy Mean?
The word “nuclear” has its origins in the word nucleus.
We use the term “nuclear energy” to describe the energy from nuclear fission or nuclear fusion. We harness nuclear fission by splitting atoms in a controlled chain reaction. Let’s look a little further into chain reactions.
What Is Nuclear Energy and How Is It Produced?
We know nuclear fission splits atoms into smaller atoms. When a neutron strikes an atom’s nucleus, the nucleus is split and it results in new, different atoms and neutrons. A chain reaction is a process where the neutron from a previously split nucleus strikes another nearby nucleus. The chain reaction is sustained when neutrons released in a fission procedure produce at least one more nuclear fission in at least one more nucleus. This newly-split nucleus releases its neutrons, and the process repeats.
There are two crucial distinctions in chain reactions. A controlled chain reaction takes place in nuclear reactors; scientists control the number of reactions. An uncontrolled chain reaction process is used in atomic weapons.
Nuclear reactors perform controlled nuclear fission with uranium atoms; operators can start, stop, or sustain the nuclear reactions. Uranium is the most common nuclear fuel. The nuclear fission process creates a lot of heat.
We use this heat to create electricity. Nuclear energy created around 11% of the world’s electricity in 2019 and 4.3% of all the world’s energy demands that year.
How Does a Nuclear Reactor Create Electricity?
A nuclear reactor is the engine room of a nuclear power plant. It is here that uranium atoms undergo chain reactions, releasing the uranium’s energy as heat.
The remaining part of power generation is similar to that of coal or natural gas power stations. All of these power plants generate heat, or thermal energy, either by burning fossil fuels or nuclear fissions.
A nuclear power plant’s thermal energy then heats large amounts of water to very high temperatures. The two most common types of reactor designs are pressurized water reactors (PWR) or boiling water reactors (BWR).
In a pressurized water reactor, water is heated but not boiled. The hot water is then converted into steam via a lower pressure water system, and the steam then drives turbines to create electricity. A boiling water reactor uses its reactor core to boil water and convert it directly into steam to drive the electricity-generating turbines.
Who Discovered Nuclear Energy?
The discovery of nuclear energy involved a succession of steps from various people.
It started with German physician Wilhelm Roentgen’s discovery of the X-ray in 1895. The following year, French physicist Antoine Henri Becquerel observed spontaneous energy emitting from uranium salts. Marie Curie and her husband Pierre studied his work, and they defined radioactivity in 1898.
In 1920, Englishman Ernest Rutherford — regarded as the father of nuclear physics — wrote a theory about neutrons, albeit without identifying them. British physicist James Chadwick then identified neutrons in 1932.
Otto Hahn and Fritz Strassmann successfully split a uranium atom in 1938, the birth of nuclear fission. Leo Szilard was a Hungarian-American physicist who had theorized about chain reactions. In 1939, Albert Einstein, Szilard, Edward Teller, and Eugene Wigner wrote to U.S. President Franklin Roosevelt, warning him of the dangers posed by nuclear energy if they were to be used in bombs. By 1942, Italian-born Enrico Fermi performed the world’s first chain reaction at the University of Chicago.
It took just three years and a World War for humans to use the first nuclear bomb against fellow humans. The United States dropped an atomic bomb on Hiroshima, Japan, on August 6, 1945, and followed it up three days later by bombing Nagasaki, heralding the end of World War II.
The world’s first nuclear reactor, Chicago Pile-1 (CP-1 for short), achieved a chain reaction on December 2, 1942. It took another nine years for the next step. On December 20, 1951, a reactor built at Argonne National Laboratory lit four light bulbs.
The Soviets built the first nuclear power plant to supply electricity to a grid; Obninskoye in the Kaluga region of Russia became operational on June 27, 1954. The first full-scale reactor came online in 1956 at Calder Hall in the United Kingdom.
How Do We Use Nuclear Energy in Our Daily Lives?
Nuclear energy is a potent force and can be used both for good and nefarious means. It has had a controversial past, yet many people may have spent a large part of their lives using nuclear energy, possibly without knowing.
What Are Some Examples of Nuclear Principles in Everyday Life?
We’ve seen how nuclear energy generates electricity to power our homes and businesses and how it has been harnessed to create devastating atomic bombs. Nuclear energy has many more uses, too.
Medicine: Remember Roentgen’s X-ray? We still use his discovery in hospitals worldwide, using X-rays to look for fractures, breaks, cancer, and more. Isotopes also sterilize equipment.
Art and archaeology: X-ray technology can help us delve deep into an artist’s technique, helping with restorations and verification of works, as well as explore archaeological ruins and dig sites.
Space: Nuclear batteries power unstaffed satellites to further their travel range.
Smoke detectors: These alarms use a minute amount of radioactive material to help with smoke detection.
Water quality: Many hydrogeological studies use isotopes to research water quality, sources, and chemicals present.
How Many Nuclear Power Plants Are There in the United States?
According to the U.S. Energy Information Administration, at the end of December 2020, the United States had 94 operational commercial nuclear reactors. These are based at 56 sites, and 28 states have a nuclear power plant, pumping thousands of megawatts of electricity into the grid every year.
The U.S. has used nuclear-generated electricity since 1958, and its nuclear power plant fleet has an average age of 39 years. In 2016, the last new reactor came online in the country, the Watts Bar Unit 2 in 2016 in Tennessee.
Are There Any Dangers With Using Nuclear Energy?
Nuclear energy is a potent energy source. We’ve seen that it comes with both controlled and uncontrolled chain reactions. There are 核能的优点和缺点.
But what about when things go wrong? Nuclear energy’s history is littered with world-famous examples of the dangers of nuclear power and people protesting against nuclear power.
What Are the Downsides of Nuclear Energy?
Nuclear energy relies on uranium fuel. Uranium mining, nuclear power plant processes, and nuclear waste all bring workers into contact with increased radioactivity levels.
Exposure to excessive radiation can affect people, wildlife, and the environment in many ways. Being close to a blast can cause burns, radiation sickness, cancer, and cardiovascular problems. Minor radiation exposure can increase cancer risks.
On the environmental side, nuclear power plants may discharge cooling water into rivers and oceans, warming watercourses and affecting local fish and marine life. There is also the inherent ecological cost to the materials and building involved in constructing a power plant.
For more details, be sure to view our informative guide on the 核能的优点和缺点.
Why Are Nuclear Reactors Potentially Dangerous?
Uranium is a radioactive substance used in solid pellet form in nuclear power plants. Spent uranium will continue to emit radiation for a long time after being part of a nuclear power plant’s fuel cycle.
The nuclear process creates nuclear waste; the depleted uranium, clothes worn by workers, and water are some examples. The Nuclear Regulatory Commission (NRC) regulates all aspects of the United States’ nuclear industry, from materials to power plants.
Each element is graded as high-level or low-level radioactive waste; spent fuel is high-level, for example. This spent fuel is stored at sites, usually buried deep underground. Low-level wastes are typically buried in shallow, secure repositories, often onsite. Once the low-level waste is no longer considered dangerous, it heads to commercial processing facilities. There are eight in the United States, including one in New York.
What Are Some Examples of Nuclear Power Plant Disasters?
There are many famous examples of nuclear power plant disasters.
Chernobyl
The world’s worst incident was at Chernobyl in Ukraine on April 26, 1986. An explosion exposed the core, and clouds of radioactive waste spread around the area. There were fewer than 100 immediate deaths, but various agencies estimate deaths from radiation sickness to total 4,000 to 90,000 people. The environmental damage caused was also enormous.
Fukushima
In March 2011, a massive earthquake off the east coast of Japan triggered a tsunami that killed 18,000 people. The waves flooded the Fukushima Daiichi nuclear power plant defenses, knocking out emergency generators cooling the cores.
Nuclear fuel in three reactors partially melted, and explosions damaged buildings and sent radioactive waste to the Pacific Ocean. No one died immediately, although many dozens of people were treated for radiation sickness. More than 500,000 people were evacuated.
Three Mile Island
This location in Pennsylvania was the United States’ most serious nuclear disaster — and it was 60 minutes away from being far worse. On March 28, 1979, in the early morning hours, a pressure valve in a reactor failed to close. Workers failed to respond adequately and a series of decisions meant the plant was just one hour away from a complete meltdown.
In all cases, the clean-up operations took years and cost many millions or billions of dollars, with long-term health and environmental costs still not known.
What Are the Benefits of Nuclear Energy?
Nuclear energy has supplied power to homes and industry for many years. It’s classified as carbon-free because it does not produce carbon dioxide emissions that are pushing global warming and climate change. It’s a very reliable energy source that can be controlled, increasing or decreasing production as needed.
Is Nuclear Energy Clean Energy?
From a greenhouse gas emissions perspective, nuclear energy is considered clean energy because it doesn’t produce any CO2 emissions.
Environmental groups cite radiation seeping into the environment and the potential for more disasters as a reason to abandon nuclear power or stop labeling it as clean energy.
Advanced reactors may push nuclear into a more efficient and less polluting era. There are few in existence, but advanced reactors are expected to be smaller than current reactors. The industry is also looking at using molten salt as a coolant in its processes.
A final development is maybe switching to nuclear fusion, joining atoms like the sun, rather than the current nuclear fission process. Nuclear is definitely seen as part of the globe’s clean energy future.
Is Nuclear Energy Renewable or Nonrenewable?
Uranium, like any material found on Earth, is finite. In that sense, nuclear energy is a non-renewable energy source because it is not replenishable, and the resource (uranium) will eventually run out.
Nuclear doesn’t feel as renewable as geothermal, solar power, hydropower, or wind power. We know that the sun will shine, the Earth’s core will remain warm, water will flow, and the wind will blow for many thousands of centuries.
However, studies suggest there may be more than 200 years of uranium available to mine. The hopes for nuclear fusion and technology advances, give the industry great hopes of maintaining nuclear as part of the energy mix for a long time yet. Using those metrics, nuclear is considered renewable energy.
Is Nuclear Energy Potential Energy or Kinetic Energy?
Potential energy is stored energy, while kinetic energy is the energy of movement. Nuclear energy comes from the potential energy stored in atoms. We release that potential stored energy when we split the atom.
What Is the Future of Global Nuclear Energy?
Nuclear energy is a survivor. It came through its horrific deployment as a weapon of mass destruction to become a helpful electricity generator. Despite nuclear power plant safety incidents — including some catastrophic disasters — nuclear energy remains an integral part of the world’s energy mix.
Protests about the harm caused by radioactive materials, from storage to transportation, still haven’t eradicated nuclear energy. As the world focuses on carbon dioxide emissions, the nuclear industry has repackaged itself as a low-carbon energy source.
Splitting the atom was an incredible feat, and the repercussions of unleashing that energy are still being felt. Nuclear energy is here to stay, for now. Its future in the sustainable energy mix may depend on its ability to market itself for what it already is — a reliable source of energy.
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