James Cricchio 5/28/07
Fusion power
As technology over time progresses and makes life much easier for humanity, man exploits this technology without considering the consequences that could occur in a much broader scheme for the future. Man has pushed its limits to the point where no longer can we thrive on the very source of energy that we so carelessly abused for our own personal economical gain. For years, the United States has been dependent on the oil provided by the middle east. Well at a time of war, increasing gas prices, and dependency on such limited amounts of available energy, we all must find new sources that are friendly to the environment. Scientists have used environmental methods such as solar, wind and water as sources of power, but one of the additions that is hot debate is nuclear power. To be more specific, fusion power is being considered as a new source of renewable energy for the whole world. However, although the safety of fusion power is quite secure and its highly effective in producing heated energy, the practicality of economically viable power plants are still in the works.
Like the character of Doctor Otto Octavius (aka Doctor Octopus) of the Spider-man comic books, he was a brilliant nuclear physicist who researched atomic physics. To perform a sustained fusion experiment, Octavius developed a set of artificial mechanical arms, which are impervious to heat and magnetism. This would allow the doctor to handle the experiment from a safe distance. Yet when the fusion reaction becomes unstable it explodes on Octavius bonding the mechanical harness to his skin. In the movie for Doctor Octopus however, filmmakers took a more realistic take. Instead of the fusion reaction exploding on Octavius, instead the fusion reaction is fueled by tritium, overloads and becomes unstable. This second sun is now growing and gaining a gravitational pull on its own acord. In order to stop it from gaining momentum, the fusion reactor had to be drowned in the Hudson River. Mind you, this is all works of fiction with hints of scientific knowledge woven in. This shows how although we are skeptical on the safety of nuclear fusion power, we know some of the possible consequences that could occur. Whether it is accurate or not, these science fiction writers are explaining sources of power beyond our comprehension and for a time like the early 1960s, nuclear power was cutting edge and never thoroughly used before.
Fusion power refers to power generated by nuclear fusion reactions. In this kind of reaction, two light atomic nuclei fuse together to form a heavier nucleus and release energy. In a more general sense, the term can also refer to the production of net usable power from a fusion source, similar to the usage of the term "steam power." Most design studies for fusion power plants involve using the fusion reactions to create heat, which is then used to operate a steam turbine, similar to most coal-fired power stations as well as fission-driven nuclear power stations. Unfortunately, despite optimism dating back to the 1950s about the wide-scale harnessing of fusion power, there are still significant barriers standing between current scientific understanding and technological capabilities and the practical realization of fusion as an energy source. Research, while making steady progress, has also continually thrown up new difficulties. So it remains unclear that an economically viable fusion plant is possible. The basic concept behind any fusion reaction is to bring two or more atoms very close together, close enough that the strong nuclear force in their nuclei will pull them together into one larger atom. If two light nuclei fuse, they will generally form a single nucleus with a slightly smaller mass than the sum of their original masses. The difference in mass is released as energy according to Einstein's mass-energy equivalence formula E = mc². If the input atoms are sufficiently massive, the resulting fusion product will be heavier than the reactants, in which case the reaction requires an external source of energy. The easiest way to do this is to heat the atoms, which has the side effect of stripping the electrons from the atoms and leaving them as bare nuclei. In most experiments the nuclei and electrons are left in a fluid known as a plasma. Because hydrogen works at the lowest temperature and because helium has generally a low mass, most fusion reactions combine isotopes of hydrogen ("protium", deuterium, or tritium) to form isotopes of helium (3He or 4He). This makes it easy to fuel fusion reactions, but the negative side-effect for the environment is the exploitation of natural gases.
The natural product of a fusion reaction is a small amount of helium, which is completely harmless to life and does not contribute to global warming. Tritium is of more concern because like other isotopes of hydrogen, it is difficult to retain completely. During normal operation, some amount of tritium will be continually released. There would be no acute danger, but the cumulative effect on the world's population from a fusion economy could be a matter of concern. The 12 year half-life of tritium would at least prevent unlimited build-up and long-term contamination. The likelihood of a catastrophic accident in a fusion reactor in which injury or loss of life occurs is much smaller than that of a fission reactor. The primary reason is that the fuel contained in the reaction chamber is only enough to sustain the reaction for about a minute, whereas a fission reactor contains about a year's supply of fuel. Furthermore, fusion requires very extreme and precisely controlled conditions of temperature, pressure and magnetic field parameters. If the reactor were damaged, these would be disrupted and the reaction would rapidly extinguish. Fusion is not a chain reaction and therefore cannot run out of hand. Under normal conditions, the fusion process runs at the fastest possible rate, and any alteration from this leads to a decrease in energy production. Large-scale reactors using neutronic fuels and thermal power production (turbine based) are most comparable to fission power from an engineering and economics viewpoint. Both fission and fusion power plants involve a relatively compact heat source powering a common steam turbine-based power plant, while producing enough neutron radiation to make activation of the plant materials problematic. The main difference is that fusion power produces no high-level radioactive waste, though activated plant materials still need to be disposed of. There are some power plant ideas which may significantly lower the cost or size of such plants.
It is far from clear whether nuclear fusion will be economically competitive with other forms of power. The many estimates that have been made of the cost of fusion power cover a wide range, and indirect costs of and subsidies for fusion power and its alternatives make any cost comparison difficult. The low estimates for fusion appear to be competitive with but not drastically lower than other alternatives. The high estimates are several times higher than alternatives. Fusion power has many of the benefits of long-term renewable energy sources, such as sustainable energy supply and no greenhouse gas emissions, as well as some of the benefits of such relatively finite energy sources as hydrocarbons and nuclear fission without reprocessing. Like these currently dominant energy sources, fusion could provide very high power-generation density and uninterrupted power delivery. They work independent of the weather, unlike wind and solar power.
In conclusion, scientists have proved that fusion power is an effective energy source, yet the chances of it becoming a main energy source economically is highly unlikely in our time. There are still difficulties scientists have yet to overcome and there are negative side effects to the fact that fusion reactions need another source of energy in order to activate. Which may cause reprecussions on the world's economy.
