Understand The Truth Behind Nuclear Energy And A Nuclear Power Plant

Understand The Truth Behind Nuclear Energy And A Nuclear Power Plant

Posted 08.09.2012 in Articles by Jess

With the growing number of worldwide nuclear weapons, horrific past events and negative press, people have naturally associated the word “nuclear” with violence and destruction. And since the disasters at Fukushima and Chernobyl, many people are critical of the use of nuclear power plants as a safe source for energy.While nuclear energy can be dangerous if misused or mismanaged, it is a valuable and resilient energy resource. Once properly understood, it's easy to see that nuclear energy is a viable asset to our electricity needs now and for the future. But the question remains: If it isn't being used as a weapon, how is nuclear power harnessed as a source for energy?

Nuclear energy isn't some crazy radioactive kryptonite that scientists made for a killing weapon. It actually comes from an atom, which are tiny particles that make up every object in the universe. Nuclear energy comes from the energy in the nucleus, or core of an atom. There's a huge amount of energy in the bonds that hold the nucleus together. Breaking the bonds is what releases this enormous amount of energy. 

This energy in turn can be used to make electricity but before it can do that, the energy must be released. Energy from the atoms can be released in two ways: nuclear fusion and nuclear fission. The latter means that atoms are split apart to form smaller atoms, thus releasing energy. Nuclear power plants use this energy to produce electricity. Nuclear fusion means that energy is released when atoms are combined, or fused, together to form a larger atom. This is how the sun produces its energy. Fusion is a subject of extensive ongoing research, but it is not yet clear that it will ever be commercially feasible technology for producing electricity. 

So how do we get nuclear fuel? The most widely used substance by nuclear plants for nuclear fission is uranium. It's nonrenewable though it is a common metal found in rocks all over the world. Nuclear power plants use a certain kind of uranium known as U-235 because its atoms can be easily split apart. Most U.S. uranium is mined here in the Western United States and from there the U-235 must be extracted and processed. During nuclear fission, a small particle called a neutron hits the uranium atom and splits it releasing a great amount of energy as heat and radiation. More neutrons are released and go on to bombard other uranium atoms and the process repeats itself over and over again – or a chain reaction.

Nuclear power plants generate about one-fifth of U.S. electricity and provides about as much electricity as they use in California, Texas and New York, the three states with the most people. Not many people know this but the U.S. has 65 nuclear power plants with 104 nuclear reactors. 36 of these plants have two or more reactors. These plants are located in 31 different states but are mostly located east of the Mississippi. Most of these plants use heat to produce electricity and rely on steam from heated water to spin large turbines, which generate electricity. Instead of burning fossil fuels to produce the steam, nuclear plants use heat given off during fission. The uranium fuel is then formed into ceramic pellets which are about the size of your fingertip. While these may be small, each one produces roughly the same amount of energy as 150 gallons of oil.

These pellets are stacked end-to-end in 12-foot metal fuel rods. These bundles of fuel rods, sometimes hundreds, are called a fuel assembly and each reactor core contains many fuel assemblies. The heat that's given off during fission in the reactor core is used to boil into steam, which turns the turbine blades. As the turbines turn, they drive generators that make electricity. The steam is then cooled back into water in a separate structure at the power plant called a cooling tower. The leftover water can be used again and again.  

In terms of how good or bad nuclear power plants are for the environment, they do not produce any air pollution or carbon dioxide while operating. However, the process for mining and refining uranium ore and making reactor fuel require large amounts of energy. They have large amounts of metal and concrete, which also require large amounts of energy to manufacture. The main environmental concerns are radioactive wastes such as uranium mill tailings, spent (used) reactor fueled, and other radioactive wastes. They can remain radioactive and dangerous to human health for thousands of years. Regulated by the U.S. nuclear Regulatory Commission. There are two different types of radiation waste: lo level radioactive wastes and high level. Low level radioactive wastes are the tools, protective clothing, wiping cloths, and other disposable items that get contaminated with small amounts of radioactive dust or particles at nuclear fuel processing facilities and power plants. High level radioactive waste consists of “irradiated” or used nuclear reactor fuel (i.e., fuel that has been used in a reactor to produce electricity). The used reactor fuel is in a solid form consisting of small fuel pellets in long metal tubes. 

Once they're done with the fuel, they don't just dump it in the river or outside wherever they are. Spent reactor fuel assemblies are highly radioactive and must initially be stored in specially designed pools resembling large swimming pools where water cools the fuel and acts as a radiation shield, or in specially designed dry storage containers. There is currently no permanent disposal facility in the U.S. for high-level nuclear waste. High level waste is being stored at nuclear plants.

Because it can be dangerous, nuclear reactors and power plants have complex safety and security features. The risk of a widespread contamination of air and water with radioactivity for hundreds of miles around a reactor is very small due to the diverse and redundant barriers and numerous safety systems at nuclear power plants, the training and skills of the reactor operators, testing and maintenance activities, and the regulatory requirements and oversight of the Nuclear Regulatory Commission. A large area surrounding nuclear power plants is restricted and guarded by armed security teams. U.S. reactors have containment vessels that are designed to withstand extreme weather events and earthquakes. 

Once the idea of nuclear power is out of the way, nuclear energy is just as harnessable as wind or solar power. Advances in technology and infrastricture have allowed for nuclear power plants to become safer, 

Image (CC) Idaho National Laboratory  

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