Nuclear Reactors
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By: Kalindu Gamalathge
Nuclear Reactors
They are many types of Nuclear Reactors they vary from experimental fusion reactors to the more common Pressurized Water Reactor. Nuclear Energy is the energy released during nuclear fission or fusion, especially when used to generate electricity. Nuclear Energy provides 10.9% of all electricity produced and it is still the most efficient way to produce power without emitting greenhouse gasses into the atmosphere. Nuclear energy has been around for 75 years now and has had its upbringing and decent. Nuclear Energy is a proven technology but it’s also uses some old outdated technology and still uses the same concept because we still haven’t had enough funding to get a up and running fusion reactor which is pretty much free power if we can find a way to make it work.
Fission:[pic 2]
Nuclear Fission can be obtain by the energy manipulating one or several nucleus of atoms through splitting of a given atom nucleus. Fission Reaction originates from the splitting of Uranium 235 atom. It does it by absorbing a neutron and fissions into two new atoms. This generates heat to produce steam, which is used by a turbine generator to generate electricity.
Fission reactors is the most common type of Nuclear Reactor because the technology is proven to work effectively, because nuclear power plants generate electricity 24/7 at a 91 percent capacity factor which makes it the most effective form of making electricity. Nuclear energy has the least effect on nature since it doesn’t discharge any gasses like methane and carbon dioxide. Nuclear Reactors are also one of the cleanest forms of creating energy because it does not burn any fuels it has one of the lowest CO2 per kWh at a 16g per every kWh compared to the 1001g of CO2 from 1kWh of coal, 848g of CO2 for every kWh produced from oil, 469g CO2 for every kWh produced from forms of gas and 46g of CO2 for every kWh of solar energy produced. Nuclear Power produces a large amount of energy from the smallest amount of Uranium. The normal life of nuclear reactor is anywhere from 40 to 60 years. This small amount of uranium required means they will be saving resources and it will be cheap to import and export because you don’t need a huge amount of uranium to produce energy. [pic 3][pic 4]
Nuclear Energy also has a bad side the actual process of nuclear fission emits radiation that is harmful to human being that can cause anemia and many different types of cancers. This is why they wear protective gear because it is required for people working in nuclear plants. The biggest problem with nuclear fission despite the importance of nuclear fission to produce energy for electricity is the same process that results to the production of waste materials that are extremely harmful to both the people and the environment. And with the buildup of nuclear waste without proper disposal sites, government organizations will have to look for locations to dump these product wastes. There have been recorded accidents that occurred in nuclear power plants resulted to deaths. Although when it comes to the amount of fatalities, accidents resulting from other sources are higher. In terms of the drain to economy, disasters in nuclear plants are far more expensive to address because it involves closing the plant and relocating the people who might be affected. Nuclear has always been looked down at because of incidents like Chernobyl and Fukushima which cause mass havoc and mayhem this also caused massive loss of life and a huge relocation of people
Pressurized Water Reactors
Pressurized Water Reactors make up a large majority of the worlds nuclear power plants. Ordinary water is used as both neutron moderators and coolant. In a Pressurized Water Reactors the water used as moderator and primary coolant is separate to the water used to generate steam and to drive a turbine. In order to efficiently convert the heat produced by the Nuclear Reaction into electricity, the water that moderates the neutron and cools the fuel elements is contained at pressures 150 times greater than atmospheric pressure.[pic 5]
Boiling Water Reactors
This design has many similarities to the Pressurized Water Reactors except that there is only a single circuit in which the water is at lower pressure so that it boils in the core at about 285°C. The reactor is designed to operate with 15% of the water in the top part of the core as steam, with less moderating effect and therefore efficiency there. Boiling Water Reactor units can operate in load following mode more readily then Pressurized Water Reactor .The steam passes through drier plates called the steam separators above the core and then directly to the turbines, which are thus part of the reactor circuit. Since the water around the core of a reactor is always contaminated with traces of radionuclides, it means that the turbine must be shielded and radiological protection provided during maintenance. The cost of this tends to balance the savings due to the simpler design. Most of the radioactivity in the water is very short-lived, so the turbine hall can be entered soon after the reactor is shut down. [pic 6]