Topics to be covered:-1. Nuclear fission2. Nuclear fusion3. Nuclear Fuel4. Atom bombs5. Nuclear Power stations6. Nuclear waste7. Controlling rate of reaction8. Benefits of fission9. The fusion Bomb
Nuclear fissionIn one of the most remarkable process in nature, aslow neutron can be captured by a uranium-235nucleus, rendering it unstable toward nuclear fission.A fast neutron will not be captured, so neutrons mustbe slowed down by moderation to increase theircapture probability in fission reaction.A single fissionevent can yeild over 200 million times the energy ofthe neutron which triggered it!!!!!!
Nuclear fusionNuclear fusion is the energy source of the future. It iswhat provides the sun and the stars with the energyto shine continously for billions of years. Fusion hasbeen used here on earth to produce nuclearbombs,but has not yet been controlled yet so that wecan obtain useful energy.We will try to show howfusion works, and describe current efforts to tamethis limitless energy source.
The first generation fusion reactors will usedeuterium and tritium for fuel because they will fuseat a lower temperature. Deuterium can be easilyextracted from seawater, where 1 in 6500 hydrogenatoms is deuterium. Tritium can be bred fromlithium, which is abundant in the earths crust. In thefusion reaction a deuterium and tritium atomcombine together, or fuse, to form an atom of heliumand an energetic neutron.It only takes a small amount of these isotopes toproduce a lot of energy! The deuterium-tritium fusionreaction results in an energy gain of about 450:1!! Noother energy source we can tap releases so muchenergy for the amount that is input.
Nuclear fuelSome of the most commonly used elements are:-1. uranium-2352. Plutonium-2383. Lithium (tritium source)4. And some other elements
When uranium-238 absorbs a neutron it turns intouranium-239 and this decays by giving out beta radiationsto form neptunium-239, which in turn decays again bybeta radiations to form plutonium-239. Plutonium alsoundergoes fission and can be used as a fuel and also in themanufacturing if nuclear weapons. In this way, as theuranium-235 is used up, it actually makes plutonium-239.This can be extracted and used for subsequent energyproduction or bombs.The fissioning of uranium-235 in the reactor of a nuclearpower plant produces two to three neutrons, and theseneutrons can be absorbed by uranium-238 to produceplutonium-239 and other isotopes. Plutonium-239 can alsoabsorb neutrons and fission along with the uranium-235.Plutonium fissions provide about one-third of the totalenergy produced in a typical commercial nuclear powerplant. The use of plutonium in power plants occurswithout it ever being removed from the nuclear reactorfuel, i.e., it is fissioned in the same fuel rods in which it isproduced.
Atom BombsAn atomic bomb is an explosive device in which alarge amount of energy is released through nuclearreactions. This makes an atomic bomb, moreproperly called a nuclear weapon, a much morepowerful device than any conventional bombcontaining chemical explosives.There are two types of nuclear weapons1. Fission weapons2. Fusion weapons
Nuclear Power StationsThere are many different designs of nuclear reactor butthey all have a nuclear reaction at the core.The energy isreleased when the nuclei splits is given to the fissionfragments.There are 400 nuclear power plants worldwide in2009, and those plants supply 16 percent of the worldselectricity. France is far and away the leader in thisregard, as nuclear plants produce 80 percent of thatcountrys power. In the United States, 104 nuclear powerplants produce 20 percent of all electricity. Thirteen ofthose plants are in Illinois, the most of any state.
Its EnvinronmentalImpactNuclear energy accounts for 73% of total electric powergeneration in United States. Even its envinronmentalimpact is not so long lasting as most of its wastebyproducts are buried underground.How is power createdThe fission of an atom of one atom of uranium can createas much energy as 10 million times one atom of coal canproduce. One ton of uranium can produce more energythan several million tons of coal or several million barrelsof oil.
Nuclear WasteNuclear waste are those that contain radioactive materials.These byproducts which are released are hazardous to humanhealth and enviornment.Radioactivity diminishes over time. So some of the waste can bestored until no longer it poses a problem.Low level waste withlow level of radioactivity can be stored only for days or weeksbut on the other hand high level waste with high level ofradioactivity have to be store for month or thousands of years.There are numerous sites that contain or are contaminated withradioactivity. Despite copious quantities of waste, theDepartment of energy has stated a goal of cleaning all presentlycontaminated sites successfully by 2025.
Benefits of fissionThe biggest advantage is that it is an established way to generate electricity withoutemitting carbon dioxide. This is more and more important as global warming becomes areal threat to the environment.It also does not emit other pollutants into the air, such as smog or particulates.nuclear power production does not contribute any harmful gases to the atmosphere. nocarbon, no acid, no sulfur. It is safe, contained, and can produce as much as 5 lbs. of coalwith a fuel pellet weighing 6 grams!The advantages are that nuclear power plants make 33% of the United States electricity.They also make 15% of the worlds electricity. The good thing is that to make all thiselectricity they dont burn anything like coal or wood. This means they dont pollute the airso it keeps the environment clean near the plants. In fact they have discovered that manyendangered species of animals live very near to the power plants. Nuclear energy is themost concentrated energy on the earth so we can control it very well. This is good becauserarely an explosion will occur. A nuclear power doesnt take up a lot of room so people canmake a lot of these machines all over the earth to make electricity.
Fusion BombA fusion bomb is a nuclear explosive that is powered by a hydrogen fusionreaction. The force is much greater than that of a conventional nuclearfission bomb. The main material used for fusion bombs is the tritiumisotope of hydrogen. This is because hydrogen is the atomic element withthe lightest weight. This makes it an ideal fusible material for a bomb.It is actual a fission assisted fusion bomb. That is because most hydrogenbombs are of the Teller Ulam design. This is a design where a bomb isdetonated in stages. The first stage or primary explosive is a conventionalnuclear fission bomb. This is triggered and the fission of the uraniumreleases neutrons and heat.The first fusion bomb ever detonated was “Ivy Mike” in 1952 at theEnewetak Atoll in the Pacific Ocean. The bomb though it only a firstattempt produced a yield 450 times more powerful than the nuclear bombthat was dropped on Nagasaki. The largest hydrogen fusion bomb everdetonated was Tsar Bomba a Russian bomb that was detonated in 1964.