It possesses excellent corrosion resistance against most of the acids and having good strength, good weldability and fatigue resistance. The natural form of zirconium contains 0.5 to 2% halfnium which is a strong absorber of neutrons and must therefore be removed. It is frequently used for production of atomic weapons and it possesses tremendous applications in breeder reactors. It is identified as highly toxic and chemically very reactive material.
It is a concentrated type of fuel used in a fast reactor without a moderator. It is produced through the absorption of neutrons by uranium 238 and subsequent beta decays. Plutonium is not a natural element but synthetic. Thorium like uranium is an emitter of alpha rays and releases considerable quantity of the radioactive products during processing, but this being a cubic metal is less susceptible to irradiation damage. Uranium addition increases the strength of thorium. Small additions of titanium, zirconium, and niobium decrease the strength and hardness of the metal. Its mechanical properties change drastically by small addition of impurities.
In its pure form it is weak and soft, but its mechanical properties are improved by adding small amount of other elements e.g., only 0.2% of carbon addition raises its tensile strength from. It can be converted into uranium by beta decay. It can be converted into uranium by beta decay.
IODINE STARBOUND FREE
It is a nuclear fuel and is free from phase changes below 1480☌. Thorium is another possible fuel and is also a radioactive metal like uranium. But it has a low thermal shock resistance, poor thermal conductivity and a high coefficient of in expansion. Uranium oxide is re highly refractory, shows no phase change in an inert atmosphere, possesses a good strength and a high corrosion resistance. Uranium compounds have been found to give better service. Addition of some alloying elements such as chromium, molybdenum, plutonium and zirconium are added to make great use of this material for generating nuclear power. This metal in the pure condition is weak and is susceptible to severe irradiation damage and growth in the reactor environments. Therefore it is strengthened by a thin film of aluminium or zirconium through a rolling process known as cladding. It has a poor resistance to corrosion and needs to be protected for use as fuel elements by roll cladding a thin aluminium or zirconium jacket. It is used as a nuclear fuel and is radioactive, easily oxidized mat and exists in three allotropic forms. Most important metal found in nature and used for nuclear energy is uranium. Uranium, thorium, plutonium, zirconium, beryllium, niobium and their alloys are primarily used for nuclear engineering applications. The various metals for producing nuclear energy are used as main materials namely moderators, reflectors, fuel elements, fuel canning materials, control elements, and pressure vessel materials.
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