Type: Process Essays
Sample donated: Christian Cohen
Last updated: September 20, 2019
Nuclear fusion is the process of combining two smaller nuclei together to produce one larger nucleus.
During this process, huge amounts of energy are produced and can be captured similarly to nuclear fission. This source of power generation could be very beneficial in future, but due to the technology available, controlled nuclear fusion for a prolonged period of time is not possible yet. To produce controlled nuclear fusion in the most energy efficient way, a type of fusion called D-T fusion is used. To do this, it must be in a contained region to cause and capture the energy. This requires a hermetically sealed stainless steel container as one of the layers of containment. Since no material can withstand the intense temperatures given off by the process (between 100 and 200 million degrees celsius) the steel is not meant to contain the reaction on its own, very strong magnetic fields caused by the hydrogen plasma to contain the reaction. A magnetic field is a force field created by the magnetic forces of different objects, and can be extremely powerful.
Plasma is the state of matter where normal ionized gases are very electrically charged. The plasma is placed in the steel container and is intensely heated by an electrical current. Then atoms of isotopes of hydrogen called deuterium, a normal atom of hydrogen with an extra neutron in the nucleus, and tritium, a normal atom of hydrogen with two extra neutrons in the nucleus, are shot around the container and in the plasma. Due to the intense heat, the atoms are able to overcome their strong nuclear forces and fuse together instead of repelling from each other. When the two isotopes fuse together, there are two main products, one helium atom, and one stray neutron, as well as huge amounts of energy. Due to the power of the magnetic field of the plasma and the fact that helium atoms have an electrical charge, the helium isn’t able to escape the magnetic field, however, the stray neutron (that carries about 80% of the energy from the fusion as kinetic energy) has no charge, and can therefore bypass the magnetic field of the plasma and escape to the outer walls of the container.
These walls are made with special neutron-absorbing materials that allow the energy from the neutron to be absorbed. These large amounts of energy are then transformed into heat, and this heat is used to boil water into steam. This steam is then used to drive a turbine that generates electrical energy, and the generated electrical energy can be sent out to the areas in demand. The energy pathway of man made nuclear fusion is as follows; electrical energy is transformed from a power source into thermal energy that heats the plasma. Some of the thermal energy from the heated plasma is then transferred into the atoms of deuterium and tritium as kinetic energy in the atoms.
With the heightened kinetic energy of the atoms, there is enough kinetic energy to overcome the strong nuclear force binding the atoms together and repelling other atoms. During the process of the fusion, the total kinetic force of both atoms is collectively absorbed by the two atoms, but now as a single atoms of helium and a neutron. The absorbed energy during the fusion causes a small portion of the mass of the atoms of hydrogen isotopes to be transformed into pure energy, which is mostly shown the form of kinetic energy on the expelled neutron, while some of the energy stays within the helium atom. This kinetic energy on the lone neutron is transformed into thermal energy when the single neutron hits the neutron absorbing materials of the wall. The thermal energy captured by the wall is transferred to the water nearby, where the water gains this thermal energy.
When the water turns into steam due to the gained thermal energy, the steam builds a high pressure. This high pressured steam is used to push a turbine that transforms the kinetic energy from the turbine being turned into electrical energy which can be stored. If contained man made nuclear fusion could be controlled for a longer period of time than possible as of now, nuclear fusion would be an extremely effective source of power. Although it takes an immensely large amount of energy to create enough heat to start the nuclear reactions, there is an equally immense amount of energy given off by these reactions.
If the reaction could be sustained and controlled for long enough that the amount of energy gained from the continuous nuclear reactions would overcome the initial amount of energy required to start the reactions, there would be a huge margin of gain from this method of power generation. Other than the initial energy to heat the plasma, the process would be autonomous to run in terms of energy, providing there would be sufficient amounts of fuel, and considering that the fuels are reasonably common in either the environment or can be man made, the amount of fuel would no longer be an issue. Nuclear fusion reactors would also be non-harmful to the environment. The only waste produced from the reaction would be helium, which is already a common element in the atmosphere and is not harmful.
These power plants would need to be large to be effective, and therefore be space consuming, but there would not be need for many power plants. In the case of a plant failure or meltdown, the consequences would be very harmful, the effects would be the equivalent of setting off a hydrogen bomb on the surrounding environment, but if proper safety measurements are taken to prevent these errors, there shouldn’t be any environmental or safety issues.