User:Jeverett1995

Nuclear Fission and Fusion

Nuclear fission is quite simply described as the process by which a large atom (usually Uranium-235 or Plutonium-239) is broken into two smaller atoms. In this process, the mass of one or more neutrons is converted to energy and is expelled in massive amounts in the form of electromagnetic radiation. The equation E = MC^2 represents the energy of any given mass (M) when it is converted to energy. For example, if a neutron weighs 6.5e-27 kg, the energy resulting from it would equal (6.5e-27kg)(3,000,000 m/s)^2 = 5.85e-14 Joules.

Nuclear fusion happens when two particles of much smaller mass (deuterium or tritium, Atomic Numbers 2 and 3, respectively) collide at massive speeds to essentially "knock" a neutron off and convert it to energy. This process is much more powerful per KG of reactive material, largely because Uranium weighs more than 100 times as much as deuterium, but there is a similar amount of mass converted to energy in both reactions.

Contents

1 The Main Idea

1.1 A Mathematical Model

1.2 A Computational Model

2 Examples

2.1 Simple

2.2 Middling

2.3 Difficult

3 Connectedness

4 History

5 See also

5.1 Further reading

5.2 External links

6 References

The Main Idea There are many reasons nuclear power is preferred over conventional fossil fuel burning. With environmental standards becoming more stringent every year, energy companies are forced to begin seeking options greener and more sustainable. The main advantage of nuclear energy is the sheer power per kg of raw material. For instance, 1KG of Uranium contains 2-3 million times more energy than 1KG of coal. Furthermore, the byproducts are radioactive, but come in much less volume and are all usually safely stored underground.

[1]

Nuclear power plants have massive reactors which accelerate neutrons that are to be collided with uranium. These particles must possess enough energy to split the very powerful inter nuclear forces, and when this happens neutrons are then converted from mass to energy.

Fusion is not yet entirely harness able on a large scale, but there are multiple uses. Fusion bombs are significantly more powerful than the fission bombs from WWII. This is, as aforementioned, due to the power per KG being much higher with fusion than for fission.

A Mathematical Model As mentioned, the general equation E=MC^2 can provide significant insight on the energy production from fission. The energy created must have come from mass, and this mass's origin is not always entirely easy to follow and understand.

[1]

As you can see, there is a tiny discrepancy in mass between the reactants and the products. The mass lost is all converted to energy by the equation E=MC^2 (but remember units! u and MeV can't be used with this equation!) Where E is in joules, c is in m/s and M is in KG.

[1]

One thing to note is just how high the energy required is to split up a nucleus. This is one of the reasons why nuclear energy can create so much power from such small masses.

This information all must mean something. Without nuclear fission and fusion, most particles' energy can be measured with just total Kinetic Energy and Potential Energy due to gravity. Using the rest energy, kinetic energy and potential energy, a system's energy can now be be entirely represented in the case of a nuclear reaction taking place. The massive amount of energy can be accurately accounted for, assuming the masses of the particles before and after the reaction are known.

Examples[edit]

0.05AMU was lost as energy. How much energy was produced?

E = MC^2 C= 3,000,000 M = 0.05 * 1.66e-27 = 8.3e-29

E = (8.3e-29)(3,000,000)^2 = 7.47e-16 Joules

Two particles both of which containing 1 proton and 1 neutron collide into an alpha particle. The alpha particle has a mass of 4.00138 AMU. How much energy is produced?

Deutron Mass = 2 * (1 Proton + 1 Neutron) = 2 * (1.00728u + 1.00866u) = 4.03188 AMU.

Mass Difference = Mf - Mi = 4.00138 - 4.03188 = -0.0305 AMU

(-0.035 AMU * 1.66e-27kg) * (3,000,000)^2 = -5.22e-16 Joules

Two particles exist both of which containing 1 proton and 1 neutron. They collide, 1 particle at 5m/s, the other at 10m/s. The particle then becomes an alpha particle, which has mass 4.00153 AMU. Assuming the collision is completely elastic and all energy is converted to kinetic, what is the final speed of the alpha particle?

Total mass = 4.03188 AMU Average Speed = 10+5/2 = 7.5 m/s

KEf + REf = KEi + REi

KEf + 1/2(4.00153*1.66e-27)(3,000,000)^2

= 1/2(4.03188*1.66e-27)*7.5^2 + 1/2(4.03188*1.66e-27)(3,000,000)^2

KEf = 2.267e-16 Vf = 261,269 m/s

Connectedness[edit] Chemical Engineers have an obligation to the world to make energy production more efficient and more clean. Even with fossil fuel burning, the efficiency is drastically lower than 100% and thus millions of dollars are lost every year and the world continues to see increased CO2 emissions.

Nuclear energy is only 8% of the current energy used in the United States today. It is vastly underused, but quickly gaining ground as safety and knowledge of the process increases. It is still a very new field and the application of these powerful concepts is a whole problem in and of itself. When dealing with such radioactive, dangerous chemicals the utmost diligence must be kept. Thousands have been affected already by plant explosions and unsafe removal of the waste products. These are just a few of the main problems society is seeing with nuclear energy.

There is also an obligation for scientists to stray away from using these concepts for destruction and war. The potential energy associated with some of the new fusion bombs is surely enough to lead humanity into extinction. Furthermore, the lingering effects of radioactive decay can affect many more than those just within the blast radius.

History[edit] James Chadwick first discovered the existence of a neutron in 1932. Frederic and Irene Curie then took this concept further and discovered that radioactive materials can be created in a lab, and not just found in nature. At this time, the knowledge of radioactivity and nuclear energy was limited to radium 232. The first ever nuclear reactor became fully operational on December 2nd, 1942. The first nuclear power plant wasn't fully operational until June 27, 1954 and was built in Russia. It is called the Obninsk Nuclear Power Plant. At the time, sustaining a nuclear power plant was much more expensive than maintaining a fossil fuel plant of similar size and output energy. Of course, engineers and scientists promised cheaper costs as further research was conducted. The first commercial power plant was built in Calder Hall, England in 1956. It produced 50 MW initially, but later was upgraded to reach outputs of 200 MW. [2]

See also[edit] For more specifics, look at energy. Also, there are a variety of specific ways radioactive energy is different than most energy experienced on earth. Also, radioactivity helped researchers gain insight toward quantum physics, which is one of the most popular concepts currently being studied.

References[edit]

[1] http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html [2] https://en.wikibooks.org/wiki/Nuclear_Physics

Category: Radioactivity