Zircaloy, also incorrectly called zircalloy, is a group of of high-zirconium alloys. One of the main uses of zircalloys is in nuclear technology, as zirconium has very low absorption cross-section of thermal neutrons and therefore it is frequently used as cladding of fuel rods in nuclear reactors. Zircalloy-2 and Zircalloy-4 contain about 1.5% of tin. Other alloying elements can be niobium, chromium, iron and nickel. General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Atomic mass 91. ... An alloy is a combination, either in solution or compound, of two or more elements, which has a combination of at least two metals, and where the resultant material has metallic properties. ... NUCLEAR TECHNOLOGI ------------------ Nuclear technology is technology that involves the reactions of atomic nuclei. ... In scattering, a differential cross section is defined by the probability to observe a scattered particle in a given quantum state per solid angle unit (i. ... A thermal neutron is a free neutron with a kinetic energy level of ca. ... The term cladding has the following meanings: Regarding optical fiber in telecommunication, cladding is one or more layers of material of lower refractive index, in intimate contact with a core material of higher refractive index. ... Nuclear power station at Leibstadt, Switzerland. ... Core of a nuclear reactor A nuclear reactor is a device in which nuclear chain reactions are initiated, controlled, and sustained at a steady rate (as opposed to a nuclear explosion, where the chain reaction occurs in a split second). ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... General Name, Symbol, Number niobium, Nb, 41 Chemical series transition metals Group, Period, Block 5, 5, d Appearance gray metallic Atomic mass 92. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ...

• Zircaloy-1 consists of zirconium with 2.5% tin. However its corrosion rate was increasing over time, and to counter this effect other elements had to be added.
• Zircaloy-2 (Zry-2) consist of 98.25 weight % zirconium with 1.45% tin, 0.10% chromium, 0.135% iron, 0.055% nickel and 0.01% hafnium. [1] Other sources specify Zircaloy-2 as zirconium with 1.20-1.70% tin, 0.07-0.20% iron, 0.05-0.15% chromium, and 0.03-0.08% nickel, with tin content at lower and the iron/chromium/nickel content at the higher end of the specification. [2]

• Zircaloy-4 (Zry-4) consists of 98.23 weight % zirconium with 1.45% tin, 0.21% iron, 0.1% chromium, and 0.01% hafnium. [3]

The corrosion properties of Zircaloy-4 can be improved by adding small amount of nickel, resulting in nickel-doped Zircaloy-4, with significantly better resistance to nodular corrosion without worsening the uniform corrosion resistance and hydrogen absorption rate. [4] General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ... General Name, Symbol, Number hafnium, Hf, 72 Chemical series transition metals Group, Period, Block 4, 6, d Appearance gray steel Atomic mass 178. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... General Name, Symbol, Number hafnium, Hf, 72 Chemical series transition metals Group, Period, Block 4, 6, d Appearance gray steel Atomic mass 178. ...

Reactor-grade zirconium alloys must be made of purified zirconium free of hafnium contamination, as hafnium has very high neutron absorption cross-section, 600 times higher than zirconium. Commercial zirconium naturally contains 1-5% of hafnium which has to be removed. This removal process is difficult (zirconium and hafnium are two of the most difficult elements to separate). Two main process are in use: liquid-liquid extraction, exploiting the difference of solubility of metal thiocyanates in methyl isobutyl ketone, used mainly in United States, and extractive distillation, used primarily in Europe. The resulting reactor-grade zirconium is about 10 times as expensive as the hafnium-contaminated commercial grade. The separated hafnium is used for control rods. General Name, Symbol, Number hafnium, Hf, 72 Chemical series transition metals Group, Period, Block 4, 6, d Appearance gray steel Atomic mass 178. ... In chemistry, liquid-liquid extraction is a useful method to separate components (compounds) of a mixture. ... Thiocyanate (also known as sulphocyanate or thiocyanide) is a functional group consisting of sulfur, carbon, and nitrogen: N-(triple bond)-C-S- It has a charge of 1-. It is analogous to the cyanate ion, with oxygen replaced by sulfur. ... A pollutant that the government wants added to ethanol alcohol to prevent it from being used as a beverage, but only as a vehicle fuel instead. ... Extractive Distillation is defined as distillation in the presence of a miscible, high boiling, relatively non-volatile component, the solvent, that forms no azeotrope with the other components in the mixture. ... A control rod is a rod made of a chemical element capable of absorbing many neutrons without decaying themselves. ...

Zircaloy has a high affinity to hydrogen; absorption of hydrogen leads to hydrogen embrittlement and may lead to local or total fuel element failure and release of hot particles. General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Exposure to hydrogen causes various metals, most importantly steel, to become brittle and crack. ... A fuel element failure is a rupture in a nuclear reactor that allows the nuclear fuel or fission products to enter the reactor coolant or storage water. ... A hot particle is a small, highly radioactive object, with significant content of radionuclides. ...

Zircaloy readily reacts with oxygen, forming a passivation layer. It is more corrosion-resistant and has better neutron transparency than austenitic steel. However the corrosion resistance may degrade significantly when some impurities (eg. more than 300 ppm of carbon or more than 40 ppm of nitrogen) are present. Corrosiion resistance of zircalloys is enhanced by intentional development of thicker passivation layer of black lustrous zirconium oxide. Titanium nitride coating is sometimes used as well. General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Passivation is the process of making a material passive in relation to another material prior to using the materials together. ... Corrosion, atmospheric and biologic (Barnacles) Corrosion is deterioration of useful properties in a material due to reactions with its environment. ... The old steel cable of a colliery winding tower Steel is a metal alloy whose major component is iron, with carbon being the primary alloying material. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... Zirconia (ZrO2) is a white crystalline oxide of zirconium that is used as a refractory, in insulation, abrasives, enamels and glazes. ... TiN coated drill Titanium nitride (TiN) is an extremely hard (~85 Rockwell C Hardness or ~2500 Vickers Hardness), ceramic material, often used as a coating on titanium alloy, steel, carbide, and aluminum components to improve the substrates surface properties. ...

Other zirconium alloys are Zr705 with 5% of niobium, or reactor-grade Zr-5Nb with similar composition but hafnium-free, or 3Zi (97% Zr, 1% Al, 1% Sn, and 1% Mo, or zr97al1sn1mo1). General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Atomic mass 91. ... Aluminum is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... General Name, Symbol, Number molybdenum, Mo, 42 Chemical series transition metals Group, Period, Block 6, 5, d Appearance gray metallic Atomic mass 95. ...

There were few differences between Western and Soviet nuclear technology; one of them was the zirconium alloy composition. Reactors built with assistance of Western corporations used the zirconium-tin alloys, while reactors built with Soviet, Eastern Europe, or Chinese help used the zirconium-niobium ones.

Some zirconium alloys are biocompatible, and are used for implants. Biocompatibility is the ability of a material to perform with an appropriate host response in a specific application. ... Implants (from Latin in-, in ; and Latin plantre, to plant) are artificial devices which made to replace and act as a missing biological structure. ...