Noob questions regarding fusion and fission

In summary, Thorium has a short half-life and is not abundant enough to be practical as a nuclear fuel source, while Deuterium is a stable isotope of hydrogen and is plentiful.
  • #1
RADboy
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fission typically uses U-235 and fusion titrium- deuterium for their reactions. which is more easily obtained and more plentiful? also I've heard of a new fission fuel called thorium which has a radioactive half-life under a 10 years and is plentiful so, any info on this stuff will be appreciated.

regarding fusion... i know fission reactions release more energy per reaction because they're "stacked" with U-235 fuel. why isn't it possible to "stack" tritium-deuterium to achieve more output energy for a fusion reaction?
 
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  • #2
RADboy said:
fission typically uses U-235 and fusion titrium- deuterium for their reactions. which is more easily obtained and more plentiful? also I've heard of a new fission fuel called thorium which has a radioactive half-life under a 10 years and is plentiful so, any info on this stuff will be appreciated.

regarding fusion... i know fission reactions release more energy per reaction because they're "stacked" with U-235 fuel. why isn't it possible to "stack" tritium-deuterium to achieve more output energy for a fusion reaction?
I'm not sure what one means by 'stacked'. Nuclear fission, which typically occurs in certain heavy nuclei, e.g., U234* (= U233+n), U236*(= U235+n), or Pu240* (= Pu239 + n), releases about 200 MeV of energy in the form of kinetic energy of two lighter nuclei, the fission products, gamma-rays, and subsequent decays of the fission products, which includes beta and gamma emission.

d+t => He4 + n + 17.6 MeV.

One cannot change d or t, otherwise they'd be different elements/isotopes.

d = deuteron, or nucleus of a deuterium atom, and t = triton or nucleus of tritium atoms, both isotopes of hydrogen. Deuterum occurs in small quantities naturally, and tritum less so. Otherwise, deuterium and tritium are produced by artifical (manmade) nuclear reactions.

Thorium and uranium are naturally found and relatively abundant, but they are not infinite.

Thorium 232 has a half-live in the billions of years, but to useful as a fuel source, it is generally necessary to convert it to U-233, the fissile U-isotope. This is done in a thermal or epithermal breeder reactor, as opposed to a fast reactor, which is used to convert U-238 to Pu-239/240/241.

Look here for some basic notes on fission and fusion.
http://hyperphysics.phy-astr.gsu.edu/Hbase/nucene/nucbin.html#c5
 
  • #3
thankyou 'll try reading up more before i ask questions

i remember reading somewhere that thorium had a much shorter radioactive length.
what i mean is it does not take as long for thorium to stop emitting dangerous levels of radiation. or maybe it was toxicity? i just remember everybody was really psyched about this stuff... i also thought it was much more plentiful than U-235 even if it isn't infinite
 
  • #4
fission typically uses U-235 and fusion titrium- deuterium for their reactions. which is more easily obtained and more plentiful?

Tritium is effectively NOT found in nature in quantities sufficient enough to use as a fuel source. The reason is that tritium has a very short halflife of about 15 years I believe. It just doesn't build up on Earth because of this.

Deuterium however is a stable isotope of hydrogen and while it only makes up 0.0156% of all hydrogen in the Earth's oceans, there are sufficient quantaties available to theoretically power Earth via fusion for a long, long time. (Long long time.) <---That's a real scientific number, I assure you.:wink:

regarding fusion... i know fission reactions release more energy per reaction because they're "stacked" with U-235 fuel. why isn't it possible to "stack" tritium-deuterium to achieve more output energy for a fusion reaction?

As Astronuc pointed out, this is incorrect. Fission produces more energy per reaction because the necleus of those atoms are bulging with positively charged protons. When it fission and the nucleus splits, the combined repulsive force between the pieces generates much more energy than a single reaction of Fusion. HOWEVER, a fission reaction with Uranium involves 1 atom with an atomic mass of about 235-238. The combined mass of Dueterium and Tritium in one fusion reaction has an atomic mass of only 5. That's 47 times less mass involved per fusion reaction. (Even less if you use Deuterium-Deuterium fuel) So per nucleon, or mass, fusion releases much more energy than fission does.
 
  • #5


Thank you for your questions about fusion and fission. To answer your first question, U-235 and tritium-deuterium are both readily available in nature, but in different quantities. U-235 is naturally occurring in small amounts in uranium ore, while tritium and deuterium can be extracted from water. However, the process of obtaining and enriching U-235 for fission reactions is more complicated and expensive compared to extracting tritium and deuterium for fusion reactions. In terms of abundance, tritium and deuterium are much more plentiful than U-235.

As for thorium, it is a potential alternative fuel for fission reactions that has gained attention due to its abundance and potential for reduced nuclear waste. While it does have a shorter half-life compared to other fission fuels, it still produces radioactive waste that needs to be properly managed. Additionally, more research and development is needed to fully utilize thorium as a fuel source.

Regarding your question about stacking tritium and deuterium for fusion reactions, it is not possible to simply increase the amount of fuel to achieve more energy output. Fusion reactions require extremely high temperatures and pressures to initiate the fusion process, and increasing the amount of fuel would not necessarily increase the energy output. It is a delicate balance of fuel and conditions that is still being researched and developed for practical use.

I hope this helps to answer your questions and provide some information on fusion and fission reactions. As with any scientific topic, there is always ongoing research and advancements, so it is important to stay informed and continue to learn about these processes.
 

Related to Noob questions regarding fusion and fission

1. What is the difference between fusion and fission?

Fusion is the process of combining two or more atomic nuclei to form a heavier nucleus, while fission is the process of splitting a heavy nucleus into two or more lighter nuclei.

2. How is energy released in fusion and fission reactions?

In fusion, energy is released when the combined nucleus has a lower mass than the original nuclei, according to Einstein's famous equation, E=mc^2. In fission, energy is released when the split nucleus has a lower mass than the original nucleus.

3. What elements are involved in fusion and fission reactions?

Fusion reactions typically involve light elements such as hydrogen and helium, while fission reactions typically involve heavy elements such as uranium and plutonium.

4. Can fusion and fission reactions occur naturally?

Fusion reactions occur naturally in stars, where the extreme temperatures and pressures allow for the fusion of hydrogen atoms. Fission reactions can occur naturally in certain radioactive elements, but are typically induced in power plants for energy production.

5. What are the potential benefits and risks of fusion and fission reactions?

The main benefit of fusion reactions is the potential for clean, limitless energy production. However, it is currently very difficult to achieve and control fusion reactions. Fission reactions have been used for energy production for decades, but come with the risks of nuclear accidents and the production of radioactive waste.

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