Physics ATAR: units 1 & 2 Electrical Power Plants
FEATUREIMAGE
Risks
Fukashima nuclear accident
Lerner, K. L. (2014). Fukushima Nuclear Accident. In K. L. Lerner & B. W. Lerner (Eds.), The Gale Encyclopedia of Science (5th ed., Vol. 3, pp. 1865-1872). Farmington Hills, MI: Gale.
- Nuclear accidents A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility." Examples include lethal effects to individuals, large radioactivity release to the environment, or reactor core melt."[4] The prime example of a "major nuclear accident" is one in which a reactor core is damaged and significant amounts of radioactivity are released, such as in the Chernobyl disaster in 1986.
Nuclear cooling systems
Heat removal
A significant portion of the energy of fission is converted to heat the instant that the fission reaction breaks the initial target nucleus into fission fragments. The bulk of this energy is deposited in the fuel, and a coolant is required to remove the heat in order to maintain a balanced system (and also to transfer the heat energy to the power-generating plant). The most common coolant is water, though any fluid can be used. Heavy water (deuterium oxide), air, carbon dioxide, helium, liquid sodium, sodium-potassium alloy (called NaK), molten salts, and hydrocarbons have all been used in reactors or reactor experiments.
Some research reactors are operated at very low power and have no need for a dedicated cooling system; in such units the small amount of generated heat is removed by conduction andconvection to the environment. Very high power reactors, on the other hand, must have extremely sophisticated cooling systems to remove heat quickly and reliably; otherwise, the heat will build up in the reactor fuel and melt it. Indeed, most reactors operate on the principle that their fuel cannot be allowed to melt; therefore, the systems designed to cool the fuel must operate sufficiently under both normal and abnormal conditions. Systems that enable sufficient cooling during all credible abnormal conditions in nuclear power plants are referred to as emergency core-cooling systems.
- Nuclear reactor. (2016). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.corpus.wa.edu.au/levels/high/article/106041
Links
- Cooling Tower A structure designed to dissipate waste heat from industrial processes or thermal power generating plants. Cooling towers are most familiar to the public in connection with nuclear plants, but are utilized as well in coal, natural gas, or petroleum-powered electricity-generation plants and in some manufacturing processes. Nearly all use water as a coolant, although a few closed-system, dry process towers utilize other fluids
- Nuclear energy. (2016). In Encyclopædia Britannica. Energy is produced when the nuclei of atoms are either split (fission) or united (fusion). Fission occurs when a heavy nucleus splits into two or more lighter segments. Fusion is the combining of two light nuclei to form a single, heavier nucleus. The energy released by the fission or the fusion of nuclei, in the form of heat, light, or other radiation, is called nuclear energy. Like energy from any other source, nuclear energy can be used to do work.
- How it works - water for Nuclear Nuclear power plants generate almost one fifth of the electricity produced in the United States. The nuclear power cycle uses water in three major ways: extracting and processing uranium fuel, producing electricity, and controlling wastes and risks.
Glossary
Critical mass:
An amount of fissile material needed to produce an ongoing nuclear chain reaction.
Decay:
The breakdown of a radioactive substance over time as its atoms spontaneously give off neutrons.
Enrichment:
The process of increasing the purity of a radioactive element such as uranium to make it suitable as nuclear fuel.
Fallout:
The radioactive particles that fall back to Earth after being sent into the atmosphere by a nuclear event, such as the explosion of a nuclear bomb or the meltdown of a nuclear reactor.
Fission:
Splitting of an atom.
Fusion:
The joining of atoms to produce energy.
Meltdown:
Term used to refer to the possibility that a nuclear reactor could become so overheated that it would melt into the earth below.
Pile:
A mass of radioactive material in a nuclear reactor