Nuclear Power | Nuclear Power in the US | East Coast Nuclear
Whether you think it’s the greatest thing since sliced bread or a major threat to our country, the fact is that the United States relies on nuclear power. The US is home to 104 operational nuclear power plants that are managed by 30 different power companies. In 2009 these plants generated 799 billion kilowatt hours of power which translates into approximately 20% of the total electrical output of the United States, a hefty contribution. In addition to operating plants, there are also 36 research and test reactors housed across the country at universities where they are used for research, testing, and training.
Nuclear Power Plants | Nuclear Reaction Basics
Obviously, a nuclear power plant is used to generate electricity but how is the process different from a coal burning power plant? Actually, in essence a nuclear power plant creates energy in an identical manner to a typical fossil fuel burning power plant, the difference is the energy source. Both types heat water into pressurized steam that is used to drive a turbine generator that converts mechanical energy into electricity by electromagnetic induction. A standard coal burning power plant generates heat by burning fossils fuels, which provides the energy to the turbine. Conversely, a nuclear power plant gets this energy from a process called induced nuclear fission.
Nuclear fission is essentially the splitting of an atom. It is a process where an atomic nucleus absorbs a neutron and splits into two or more lighter elements, releasing free neutrons and radiation. Uranium undergoes spontaneous fission very slowly, but scientists have discovered that fission using Uranium-235 can be induced. U-235 is concentrated in a nuclear reactor to around 2 to 3% (this is called enriched uranium) so that the free neutrons generated by fission have a high probability of coming into contact with more U-235 nuclei which will then also undergo fission setting off a nuclear chain reaction. The splitting of these atoms generates an incredible amount of heat which is then used to heat water into steam and drive a turbine to create electrical energy. The process is very thermogenic, in fact, 1 kilogram of U-235 contains approximately 3 million times the energy of 1 kilogram of coal. With so much energy and heat released, it is vital to control the rate of the reaction to prevent overheating. The rate of the nuclear reaction is controlled by inserting graphite control rods that absorb free neutrons and halt the reaction.
Now that you have a basic understanding of how nuclear reactors generate power let’s take a look at the type of power plants currently in use in the United States. There are 2 types of nuclear power plants currently operating in the US:
- Pressurized Water Reactors (PWRs)
- Boiling Water Reactors (BWRs)
Pressurized Water Reactor
Nuclear Power | Pressurized Water Reactors | PWRs
PWRs typically operate by allowing the fission reaction to occur in the reactors core (1) which is kept at under high pressure and creates heat but not steam. Pressurized water (2) carries the heated water to a steam generator (3) where a lower pressure allows the heated water to form steam that is directed to a turbine generator (4) and used to generate electricity. The unused steam is condensed back into water in a condenser and pumped back into the reactor core.
Boiling Water Reactor
Nuclear Power Plants | Boiling Water Reactors
BWRs, such as the one involved in the Japanese Fukushima incident, are similar to a pressure cooker. The nuclear material is contained in the reactor core (1) which generates heat and steam (2) which moves upward where the steam and water are separated by a steam separator (3) before the steam is allowed into the steam line (4) which directs the steam to a turbine generator and generates electricity. Unused steam is condensed back into water and back into the reactor core.
Therefore, the main difference between PWR and BWR system is that the steam in a PWR is produced in a steam generator, not the reactor core. In constrast, the steam is created directly in the reactor core with a BWR system.
Nuclear power offers some potentially rewarding benefits as well as some unique risks. Some people are strongly if favor of nuclear power while others are vehemently opposed. You can decide for yourself on which side you fall. Here is list of a view points from each side.
Advantages and Disadvantages of Nuclear Power
- Nuclear power emits very lower levels of carbon dioxide and therefore does not contribute to Global Warming or environmental contamination.
- One plant can generate a large amount of electricity.
- Nuclear energy is thought to be the cheapest form of energy and therefore has vast economic implications.
- Reduced reliance on fossil fuels and their increasing costs.
- Nuclear power plants generate dangerous radioactive waste that must be stored for many years. If obtained by a terrorist group this material could be used in the construction of a nuclear weapon.
- Uranium supply is limited and expected to last only 30 to 60 years.
- Plant construction can take decades to get up and running.
- Plant failure. Under unusual circumstances nuclear plower plants can fail, as it is impossible to build a plant that is immune to every conceivable natural or man-made disaster. The biggest threat is an explosion or leak that allows harmful radioactive material to escape into the environment. See Chernoby disaster for more information.
Nuclear Power Plants in the United States
With 104 nuclear power plants in the United States (69 PWRs and 35 BWR) and at least 10 more units planned or currently under construction, it’s likely that you live a lot closer to one that you realize, especially if you live on the East Coast. Below is a map of the locations of the 104 currently operable nuclear power reactors. Note the high concentration on the East Coast.
Operational US Nuclear Power Plants
With so many reactors in operation in the US what areas would be at risk if one, or all, of these plants were to undergo a catastrophic failure? It's difficult to know for certain, as many factors such as wind speed and direction are unpredictable, but nukepills.com has estimated the radiation zones in the table below.
As you can see much of the area of the United States, in particular the East Coast, is at a high risk of exposure to radiation if there were to be a natural disaster similar to the 2011 earthquake and tsunami in Japan. In particular, if the East Coast were to undergo a dramatic continental shift or tsunami and damage many of these plants it it likely that almost 50% of the US could be at risk of potential radiation exposure.
In terms of nuclear power, whether you see reward or risk, the fact is that the US currently relies heavily on nuclear power to provide energy to millions of homes throughout the country. As it is already here to stay, it would be wise to embrace it and work together to develop strategic plans to prevent any sort of major catastrophe if one of the plants ever has a major failure.
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