Basic Process - How Reactors Work - Essay Example

The boiling water reactors were the first to be developed while the pressurized water reactors came much later. In both systems, steam is generated which drives the turbines.

Thereafter, the turbines power the generators to produce electricity. Thus, the entire process leads to the generation of clean and safe electricity energy. Basic Process – How Reactors WorkFuel –thermal fission – fission fragments 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 uranium- 235 nuclei 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 produce heat in the fuel. Moreover, 2 and 3 neutrons are produced in the process. Moderator 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 number of their energy and later cause fission (Virtual Nuclear Tourist 1). Coolant nuclear fission aims 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 around the rods holding the fuel.

The fuel within the reactor exists in the form of pellets made of uranium dioxide or metal dioxide. There exist two or more isotopes of uranium and including 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 comprises 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 cases absorb the neutrons and decay to produce Plutonium 239 (Pu- 239) (Virtual Nuclear Tourist 1). The Pu – 239 may also fission with thermal neutrons. In some countries such as France, reprocessing of spent nuclear fuel occurs. The process entails the chemical separation of the plutonium from spent fuel and utilized with U – 238 in the generation of new fuel installed in the reactor.

The fuel is regarded as Mixed Oxide Fuel (MOX). Radioactive waste management Radioactive waste or radwaste comes from the nuclear fuel cycle. These wastes vary in terms of their toxicity and thus require different handling methods. The various types of radwastes include exempt wastes and very low-level wastes, low-level wastes, intermediate-level wastes, high-level wastes, wastes from mining and milling, and conversion, enrichment, and fuel fabrication wastes. Every year, nuclear power facilities generate around 200000m3 of both low and intermediate-level radioactive wastes, as well as approximately 10000 m3 of high-level wastes including used fuel (Nuclear world Association1).

Consumers of the energy compensate for the cost of managing these radwastes since it is internalized in the whole production expenditure. At every stage of the nuclear fuel process, there are proven technologies to dispose of waste. For instance, low and intermediate–level wastes are currently under implementation while, for high-level wastes, there is the use of geological repositories (Nuclear world Association1). Moreover, some countries like the USA have adopted political delay tactics.

The radioactivity or hazard levels of all nuclear wastes decrease with time, unlike other industrial wastes. After some time, radioactive wastes decay and turn into non-radioactive elements. The major objective of managing as well as disposing of radioactive wastes is to ensure the protection of individuals and the environment (Nuclear world Association1). Therefore, necessary measures are taken to ensure that radwastes remain harmless in the ecosystem as they are properly contained and managed even if it is through deep, as well as permanent burial.