How the Manipulation of Energy Propels Civilization Forward
The year is 2075 and I’m walking along the 20-mile stretch of California beach that connects Monterrey and Santa Cruz. I love spotting the numerous dolphins and occasional whale. I stop to speak with a man who is filling two large tanks with seawater. I ask him how he’s going to use it.
He says “We extract the deuterium for our personal fusion reactor in our garage. This much seawater contains only a tiny percent of hydrogen isotopes like deuterium, but it’s enough to keep our lights on for a week.” I gaze out at the Pacific Ocean and the endless waves rolling in. He sees me looking at the expanse of ocean and continues, “Each beautiful wave that arrives at this beach holds enough hydrogen isotopes to run a small city for a year.”
I was unaware that you can buy a nuclear fusion reactor for home use in California. I ask how much it costs. “It’s free,” he replies. “California offers its citizens reactors at no cost, just as they did decades ago with solar panels. As a result, electricity is abundant here. The reactor is about the size of a refrigerator. It’s in a wire cage so the kids can’t fiddle with it. With the constant threat of earthquakes here, the government decided a year ago that it was better to decentralize power production and make home nuclear fusion reactors available to everyone.”
I’m impressed. Since the dawn of humanity, our ability to capture and manipulate energy has been the driving force that has propelled civilization forward. First came fire, then steam, electricity, and finally nuclear power. But with each advancement there were also challenges, the most recent being our inability to fully control atomic fission in our generating facilities. But now, in the year 2075, the commercialization of fusion reactors has at last made nuclear power not only safe but readily available to everyone.
Today’s World Runs on Electricity
Electromagnetism was developed in the 19th century and was quickly put to industrial and residential use. It gave us the technological world we inhabit. Energy sources such as wind, tidal and solar are renewable and clean but supply only a fraction of the electric power we need.
We produce most of the electricity we require by turning a coil of copper wire in a magnetic field. As the coil turns, the magnetic field accelerates the electrons in the wire, causing an electric current to flow. Over decades, engineers and scientists have figured out ways to turn the coil and produce most of the electric power we need to run our society. Here are ways that we produce electric power.
Hydroelectricity
Dams produce electricity by harnessing the energy of falling water to turn large coils mounted around strong magnets. This process is called “hydroelectricity” or “hydropower.” It provides 16% of the world’s electricity. Hydropower is considered a clean source of energy because does not pollute the atmosphere. However, it has certain limitations. Dams can impact fish populations preventing them from migrating to spawning grounds or to the ocean. Hydropower can impact water quality and flow and can be shut down by droughts. Hydropower facilities frequently compete with other uses for land.
Fossil-Fuel Driven Power Plants
In a steam-electric power plant, fossil fuels such as coal, natural gas and oil are burned to boil water and create steam. The steam turns large coils, called turbines, to generate electricity. Unfortunately, the process causes heat-trapping gases to enter the atmosphere and raises the global temperature.
We are depleting the world’s fossil fuel deposits with an estimated 50–100 years remaining. When burned, fossil fuels produce greenhouse gases that cause climate change. Carbon dioxide emissions remain in the atmosphere for long periods, causing atmospheric and ocean temperatures to rise. A 2-degree Celsius rise in atmospheric temperature will have severe impacts on every species, including humanity. If global warming is unchecked, this rise will occur in the next decade.
Nuclear Fission Reactors
When a uranium-235 atom absorbs a neutron, it breaks or “fissions” into two fragments, releasing three new neutrons and a large amount of energy. One of those neutrons is absorbed by an atom of uranium-238. The other two neutrons can cause nearby uranium atoms to also split and release three neutrons. Scientists call this a chain reaction, and if unchecked, can cause a nuclear explosion. This is how the atom bomb works.
Heat from a self- sustaining controlled chain reaction boils the water in a nuclear power plant and generates electricity. The rate of fission is controlled by housing the rods of uranium fuel in a water bath. The water absorbs the neutrons and control the amount of heat generated.
The particles that result from nuclear fission weigh less than the original uranium atom. Some of the original atom’s mass has been turned into energy. Einstein realized that every piece of matter in the universe contains a “self-energy.” From his viewpoint, matter is just condensed energy. Einstein’s famous equation, E=MC2 quantified how much energy is locked into every atom in the universe. In this equation, E is energy, M is the mass and C is the speed of light, 300,000,000 meters per second. This equation tells us that even a small piece of any substance contains enormous hidden energy. The self-energy locked into one kilogram (2.2 pounds) of any substance is 9 million trillion joules, the equivalent of 21 million tons of the explosive TNT.
Nuclear Power Plant Accidents
In a nuclear reactor, the fuel rods are kept submerged underwater to keep them cool. Fission releases immense quantities of heat. If the heat causes enough water to boil off, the fuel rods become exposed to air. The uranium quickly melts. If the molten fuel encounters ground water, it blasts into the atmosphere and sends out clouds of radioactivity. The China Syndrome movie portrays this hypothetical disaster. It depicts the possibility that the nuclear core could melt through the planet’s mantle and core until it reached China.
Although the movie depicts a hypothetical and fictional event, nuclear fission power plants have failed, occasionally with catastrophic results. From time to time these plants leak and release radioactive liquids or gases, poisoning their surroundings. The effects of a meltdown can last for hundreds of years as the radiation slowly decays.
Since 1952 there have been fourteen meltdowns of commercial, military, and experimental reactors. Three Mile Island in 1979, Chernobyl in 1986, and Fukushima Daiichi in 2011 are the three most disastrous meltdowns to date’
On March 28, 1979, the Three Mile Island Unit 2 reactor, near Middletown, Pa., partially melted down. This was the most serious accident in U.S. commercial nuclear power plant operating history. A cooling malfunction caused part of the core to melt in the #2 reactor, which destroyed the reactor. Some radioactive gas was released a couple of days after the accident, but there were no injuries or adverse health effects to both the plant workers and the public.
The Chernobyl disaster began on April 26, 1986, with an explosion in a reactor at the Chernobyl Nuclear Power Plant, which housed four nuclear reactors. It was located about 130 km north of Kiev, Ukraine, and about 20 km south of the border with Belarus. The ensuing fire burned for ten days and released into the air radioactive elements including plutonium, strontium, iodine and cesium. Nearly 150,000 square kilometers in Belarus, Russia, and Ukraine were contaminated and was designated as the Chernobyl Exclusion Zone. The residents were evacuated and were told the Zone would be uninhabitable for thousands of years.
On March 11, 2011, the Great East Japan Earthquake of magnitude 9.0 caused a 50-foot- high tsunami that disabled the power supply and cooling tanks of three Fukushima Daiichi reactors. Three cores melted in the first three days. It took several weeks to stabilize the reactors using cool water. There were highly radioactive leaks in contaminated water in the first several days, but no deaths or radiation sickness cases were reported. Several months later, officials announced that the plants were in “cold shutdown condition.” All four reactors were deemed unusable.
Nuclear Fusion
Recall that in 1905 Albert Einstein realized that every piece of matter in the universe contains a “self-energy.” Fusion means “coming together.” When light nuclei fuse to form a heavier nucleus, they release bursts of energy. Nuclear fusion takes place in stars and the energy released makes them shine.
In a star, energy is released when four atomic nuclei fuse together. Some of the mass of the parent atoms is converted to energy when they join. The new atoms formed have a total mass slightly less than that of the parent atoms. Each second, our sun converts 4.26 million tons of hydrogen into energy. And each second it produces the equivalent of 400 million, million, million, million watts, an unimaginable amount of power. This has been going on for billions of years. The Earth receives a tiny portion of this energy, but it is sufficient to run our planet’s various systems.
How Can We Harness This Process?
If we can tame nuclear fusion- and that is a big “if”- it could supply safe, clean, and nearly limitless power. Using sea water as fuel, all of humanity can share unlimited and environmentally safe energy. But first we have to learn how to contain a plasma the size of a football and a temperature of the sun-100 million degrees Celsius- so that we can use it to heat water, run turbines and produce electricity.
The Containment Problem
To create a fusion reactor, physicists use two hydrogen gases — deuterium and tritium — heated to over 100 million degrees Celsius. The gas becomes a plasma, a superheated gas so hot that the electrons are ripped away from the atoms, forming an ionized gas.
One way to control and contain this hot plasma is to trap it in a powerful magnetic field. The ‘tokamak’, a ring-shaped magnetic chamber, is the most advanced magnetic device to date for containing plasma. Its superconducting magnets, the strongest ever produced, create a magnetic field, like rubber bands, that surrounds the plasma, a hot ball of Jell-O. As the plasma is as hot as the sun, about a million degrees Celsius, anything it touches would instantly vaporize.
The Payoff
Fusion power plants would convert energy released from fusion reactions into electricity at no cost for fuel and no adverse impact on our environment. It might also enable us to create propulsion drives to explore our solar system and interstellar space. It might eventually enable us to interact with other civilizations.
