Nuclear generators - Term Paper Example

According to the Nuclear Science Division of Lawrence Berkeley National Laboratory: “Fusion is a nuclear process in which two light nuclei combine to form a single heavier nucleus. An example of a fusion reaction important in thermonuclear weapons and in future nuclear reactors is the reaction between two different hydrogen isotopes to form an isotope of helium: Fission is a nuclear process in which a heavy nucleus splits into two smaller nuclei. An example of a fission reaction that was used in the first atomic bomb and is still used in nuclear reactors is: The products shown in the above equation are only one set of many possible product nuclei.

Fission reactions can produce any combination of lighter nuclei so long as the number of protons and neutrons in the products sum up to those in the initial fissioning nucleus.” (LBNL, 2011) Because of the nature of the source materials involved in the fusion reaction, mainly Helium and Hydrogen, the danger of radioactivity is non-existent compared to the fission processes involving Uranium and Plutonium, elements with long half-lives and radiation emissions. Fission reactions run on fuel rods of Uranium, yet the “spent” fuel rods which are no longer concentrated enough to maintain reactions at critical mass will have to be maintained and stored for thousands of years despite emitting radioactivity as part of the decay cycle.

Because of this, nuclear fusion is still viewed as a possibility to provide unlimited, “clean” energy based on nuclear reactions similar to those occurring in the sun, while nuclear fission reactions based on Uranium and Plutonium fuel power plants across the world in practical application, but long term concerns exist about the safety of the radioactive waste materials over time as the elements continue to decay and emit harmful radiation into the environment. “Plutonium-239 is one of the two fissile materials used for the production of nuclear weapons and in some nuclear reactors as a source of energy.

The other fissile material is uranium-235. Plutonium-239 is virtually nonexistent in nature. It is made by bombarding uranium-238 with neutrons in a nuclear reactor. Uranium-238 is present in quantity in most reactor fuel; hence plutonium-239 is continuously made in these reactors. Since plutonium-239 can itself be split by neutrons to release energy, plutonium-239 provides a portion of the energy generation in a nuclear reactor. Plutonium belongs to the class of elements called transuranic elements whose atomic number is higher than 92, the atomic number of uranium.

Essentially all transuranic materials in existence are manmade. The atomic number of plutonium is 94. Plutonium has 15 isotopes with mass numbers ranging from 232 to 246. Isotopes of the same element have the same number of protons in their nuclei but differ by the number of neutrons. Since the chemical characteristics of an element are governed by the number of protons in the nucleus, which equals the number of electrons when the atom is electrically neutral (the usual elemental form at room temperature), all isotopes have nearly the same chemical characteristics.

This means that in most cases it is very difficult to separate isotopes from each other by chemical techniques. Only two plutonium isotopes have commercial and military applications. Plutonium-238, which is made in nuclear reactors from neptunium-237, is used to make compact