Nuclear power Essay Example | Topics and Well Written Essays - 500 words

Nuclear power - Essay Example Thermal reactors are common in many nuclear plants in the world since they mainly use thermal fission. Thermal neutrons move within thermal equilibrium at a temperature of about 550F, corresponding to a velocity of 3700 meters per second (Virtual Nuclear Tourist 1). On striking a uranium- 235 nucleus with the fuel, the nucleus sometimes split or fission into two unequally sized nuclei known as fission fragments. The fission products comprise large positively charged particles of elements such as Iodine or Strontium. The fission products slow down immediately and producing heat in the fuel. Moreover, 2 and 3 neutrons are produced in the process. The moderator decelerates the neutrons to the thermal energy. Neutrons do not travel very far within the reactor. They are generated from fission in the fuel, jump around in the moderator, then lose a large amount of their energies and later causes fission (Virtual Nuclear Tourist 1). The aim of nuclear fission is to generate heat. Thus, the coolant removes the heat and maintains the temperature of the fuel within tolerable limits (Virtual Nuclear Tourist 1). It also cools the moderator, which can also be used to cool the fuel. In some cases, it also cools the fuel by moving round the rods holding the fuel. The fuel within the reactor exists in the form of pellets of made of uranium dioxide or metal dioxide. There exists two or more isotopes of uranium and includes U- 235 and U 238 (Virtual Nuclear Tourist 1). U -238 is common in nature and has 146 neutrons and 92 protons. The remaining portion comprise of U – 235 and U 234. In commercial nuclear reactors, the fuel has a higher concentration of U- 235 compared to the level found in nature. It will undergo thermal and fast fission when struck by neutrons. Consequently, U – 238 will also undergo fission when struck by quick moving neutrons of specific energies and can in some case absorb