Nuclear fusion is the process where the nuclei of two light atoms combine to form a new nucleus. This is another way of producing nuclear energy, like nuclear fission
, although in nuclear fission the nucleus of a heavier atom splits. Now let us learn how the energy is produced by nuclear fusion.
When two light nuclei combine in a fusion reaction, the combination has a mass that is less than the mass of the initial individual nuclei. This means that the reaction gives out energy according to Einstein’s mass-energy equivalence.
An example of a fusion reaction is that of the combination of Deuterium and Tritium, which are isotopes of Hydrogen to give Helium and releasing a neutron and giving out around 17 MeV of energy.
If you have seen Spiderman 2, the movie which was released in 2004, you would’ve seen that Dr. Octavius was trying to harness the power of a fusion reaction all through the movie. He claimed that this can generate a lot of energy, which means we can obtain cheap electricity, without creating any pollutants or waste material, in a safe way. Of course, as the movie progressed he turned into a neurotic villain but he wasn’t wrong… fusion reactions are capable of doing what he claimed.
The movie shows the reaction going out of control and trying to absorb everything that is metal around it. He is shown to have created a perpetual sun! This is completely for entertainment purposes and won’t actually happen. Even if an uncontrolled nuclear fusion reaction is capable of exploding, this won’t happen. And why not? Before we get to that let me tell you about the types of fusion reactors.
Types of Fusion Reactors:
Based on confinement we can separate these reactors into two types.
Here, the hot plasma is checked from touching the walls of the confining material by use of magnetic fields. The temperatures achieved are extremely high and therefore they are kept from touching material
Here, the high energy density is put into a small pellet of reactors fusing them in such a short span that they don’t have the time to touch the confining material
Why the Fusion Reaction in Spiderman couldn’t have happened that way!
Nuclear fusion is actually very safe. The reason why it isn’t being used as widely as it can be because these type of reactions require PRECISE conditions in terms of temperature, pressure, raw material and even confinement. If, even one of the conditions isn’t satisfied the reaction actually stops.
The energy spent to achieve these specific conditions surpasses the amount actually produced by the reaction. This is not feasible on a large scale.
And this is also why that scene in Spiderman is incorrect. If the reactor were damaged or any of the parameters changed (quite drastically as shown in the movie) the reaction would immediately stop and cool down! And was it confined?
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