Nuclear Fusion
Fission vs. Fusion
Uses
Current Uses
- Power generation
- Fusion is the energy source for the sun.
- For scientific research
- The main application for fusion is in making electricity
What is it?
Nuclear fusion is the fusing of two or more lighter atoms into a larger one.
It's a process where atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
Potential Uses
- Nuclear fusion will be used as a power source. It is what the sun does to generate energy, and as a species, we are now trying to use a sun-like plasma in a controlled environment.
Fusion occurs in stars, such as the sun.
ITER - The Future of Nuclear Fusion
Pros and Cons
Pros
- There is a lot more energy release in fusion, so it will be more profitable.
- Very low cost since the fuel source is hydrogen.
- Clean energy - no pollution or greenhouse gases
- No chain reaction. Easier to control or stop than fission.
- Little or no nuclear waste.
- Virtually limitless fuel available.
Challenges
- combining of atoms
- produces clean energy
- products are light, stable
- occurs in stars
- high density, high temperatures required
- energy released is 3x greater
- hydrogen bomb
- Fusion will only occur at temperature of 10-15 million kelvin (K), which is currently achieved using nuclear fission.
- Cold fusion is fusion at a low enough temperature to make the output energy greater than the input energy, but it is still under development.
- Once ignition is achieved and the ring plasma is sustainable, it must be held away from the walls of the tokamak using magnetism.
- Our sun's magnetic fields are what makes it sustainable as well. (Our design mimics our sun's, with the exception of the ring-shape.)
History
- Physicist F.W. Aston discovered in highly accurate experiments that four hydrogen atoms are heavier than one helium atom
- By the mid-1950s "fusion machines" were operating in the Soviet Union, the United Kingdom, the United States, France, Germany and Japan
- The design of JET, the largest fusion experiment in the world, started in 1973. Construction commenced in 1979 and the experiment was put into operation in 1983
- JET still holds the world record for the generation of fusion energy: in 1997, 16 megawatts were generated during 1 second.
- Splitting of atoms
- releases large amounts of heat/radiation
- products are heavy and radio-active
- doesn't naturally occur
- critical mass and high-speed neutrons required
- energy released is lower
- atomic bomb
- both nuclei receive action
- produce energy
Other
Nuclear Fusion Used as a Weapon - Oct. 1961
The Tsar Bomb was the biggest bomb ever, and it isn't ours. It was Russian, comrade. It was a weapon of mass destruction.
- Nuclear fusion can also be used as a weapon. Such fusion weapons are generally referred to as thermonuclear weapons or hydrogen bombs
Works Cited
Nuclear Fission
Uses
- http://burnanenergyjournal.com/historical-events-in-nuclear-fission/
- http://www.energyresearch.nl/energieopties/kernsplijting/achtergrond/historie/
- http://www.scienceclarified.com/Mu-Oi/Nuclear-Fission.html
- http://www.diffen.com/difference/Nuclear_Fission_vs_Nuclear_Fusion
- http://nuclear-fission.blogspot.com/2012/04/pros-and-cons-of-nuclear-power-as.html
- http://www.newscientist.com/article/dn17952-iter-a-brief-history-of-fusion.html
- http://www.energyresearch.nl/energieopties/kernfusie/achtergrond/historie/
- http://science.howstuffworks.com/fusion-reactor6.htm
- http://interestingenergyfacts.blogspot.com/2010/04/nuclear-fusion-facts.html
- http://www.triplepundit.com/2012/07/fusion-power-pros-cons/
- https://sites.google.com/site/rhschem2mealexander/pros-and-cons
Current Uses
What is it?
- Nuclear power plants depend on the heat that occurs during nuclear fission to make steam to make electricity
- For scientific research (provide a source of neutron beams)
- Nuclear weaponry
- Radioactive tracers (like magnesium-28) in geology, agriculture & medicine
- Iodine-131 treats Grave's Disease
Nuclear fission is the process of splitting atoms.
It's a process in which the nucleus of a heavy atom is broken apart into two or more smaller nuclei.
Potential Uses
- Proposed as a way to nudge the path of large asteroids and comets that would otherwise impact and kill all humans on Earth
- It makes a lot of energy to use for anything we want, but the radioactive waste can't be disposed off in an environment-friendly manner
- Spacecraft propulsion -- Project Orion
- Proposed as a way to rapidly excavate large amounts of rock and dirt -- Operation Plowshare
- Could potentially displace energy produced by coal, oil, and natural gas electric power plants, reducing the amount of CO2 and other pollutants into the air
Imagine a group of marbles. Then imagine throwing one marble at the group and watching all the marbles fly out in all different directions, away from each other.
Pros and Cons
Pros
- Lower carbon dioxide (and other greenhouse gases) released into the atmosphere in power generation.
- Low operating costs (relatively).
- Known, developed technology “ready” for market.Large power-generating capacity able to meet industrial and city needs.
- Existing and future nuclear waste can be reduced through waste recycling and reprocessing.
Cons
- High construction costs due to complex radiation containment systems and procedures.
- High-known risks in an accident.
- Long construction time.
- Target for terrorism (as are all centralized power generation sources).
- Waste lasts 200 – 500 thousand years.
- Risk of Meltdowns. If there is a loss of coolant water in a fission reactor, the rods would overheat.
History
Fission History (Brief)
- The fission reaction was discovered accidentally in 1938 by two German physicists, Otto Hahn and Fritz Strassmann. (They were doing a series of experiments in where they used neutrons to bombard various elements.) Hitler had this information.
- German physicist Lise Meitner (1878–1968) and her nephew Otto Frisch explained why an atom of uranium (element number 92), when struck by a neutron, broke into two much smaller elements such as krypton (element number 36) and barium.
- A year into World War II (1939–45), a number of scientists had come to the conclusion that the United States would have to try building a fission bomb.
Albert Einstein warned F.D. Roosevelt that his equation (e = mc2) was being used in this way and that the atom bomb was imminent - both in Nazi Germany and in the U.S.
Other
Be Safe!
Facts
- Nuclear power plants produce about 20 percent of America's power.
- There are over 400 nuclear power plants worldwide.
- While nuclear energy produces less waste than fossil fuels, its radioactive waste must be stored in special containers and buried beneath the earth's surface, typically in a mountain, until it is no longer hazardous.
- Almost 3 million Americans live within 10 miles of an operating nuclear power plant.
- Nuclear energy comes from uranium, a nonrenewable resource that must be mined.
- In 2009, America produced 798.7 billion kilowatts of nuclear energy, more than twice that of any other country and over 30% of all the nuclear energy generated worldwide that year.
- Every 18 to 24 months, a power plant must shut down to remove its spent uranium fuel, which has become radioactive waste.
- United States power plants produce 2,000 metric tons of radioactive waste every year.
- In 2008, nuclear power replaced an estimated 690 million metric tons of carbon dioxide from entering the atmosphere.
- Nuclear power plants generate nearly three-fourths of America's clean-air energy.
Your skin protects you from most background radiation (from smoke detectors, the sun & other stars, computers, TVs, etc.), but in the event of a nuclear fallout, Potassium Iodide can help!
Nuclear Fission and Fusion
Venn Diagram Notes