Uranium how is it used

Glossary Allotropes Some elements exist in several different structural forms, called allotropes. Glossary Group A vertical column in the periodic table.

Fact box. Glossary Image explanation Murray Robertson is the artist behind the images which make up Visual Elements. Appearance The description of the element in its natural form. Biological role The role of the element in humans, animals and plants. Natural abundance Where the element is most commonly found in nature, and how it is sourced commercially.

Uses and properties. Image explanation. The image is based around the common astrological symbol for the planet Uranus. Uranium is a very important element because it provides us with nuclear fuel used to generate electricity in nuclear power stations.

It is also the major material from which other synthetic transuranium elements are made. Uranium is the only naturally occurring fissionable fuel a fuel that can sustain a chain reaction. Uranium fuel used in nuclear reactors is enriched with uranium The chain reaction is carefully controlled using neutron-absorbing materials. The heat generated by the fuel is used to create steam to turn turbines and generate electrical power. In a breeder reactor uranium captures neutrons and undergoes negative beta decay to become plutonium This synthetic, fissionable element can also sustain a chain reaction.

Depleted uranium is uranium that has much less uranium than natural uranium. It is considerably less radioactive than natural uranium. It is a dense metal that can be used as ballast for ships and counterweights for aircraft. It is also used in ammunition and armour. Biological role. Uranium has no known biological role.

It is a toxic metal. Natural abundance. Uranium occurs naturally in several minerals such as uranite pitchblende , brannerite and carnotite. It is also found in phosphate rock and monazite sands.

World production of uranium is about 41, tonnes per year. Extracted uranium is converted to the purified oxide, known as yellow-cake. Uranium metal can be prepared by reducing uranium halides with Group 1 or Group 2 metals, or by reducing uranium oxides with calcium or aluminium. Help text not available for this section currently.

Elements and Periodic Table History. In the Middle Ages, the mineral pitchblende uranium oxide, U 3 O 8 sometimes turned up in silver mines, and in Martin Heinrich Klaproth of Berlin investigated it.

He dissolved it in nitric acid and precipitated a yellow compound when the solution was neutralised. He realised it was the oxide of a new element and tried to produce the metal itself by heating the precipitate with charcoal, but failed. The discovery that uranium was radioactive came only in when Henri Becquerel in Paris left a sample of uranium on top of an unexposed photographic plate.

It caused this to become cloudy and he deduced that uranium was giving off invisible rays. Radioactivity had been discovered. Atomic data. Glossary Common oxidation states The oxidation state of an atom is a measure of the degree of oxidation of an atom.

Oxidation states and isotopes. Glossary Data for this section been provided by the British Geological Survey. Relative supply risk An integrated supply risk index from 1 very low risk to 10 very high risk. Recycling rate The percentage of a commodity which is recycled.

Substitutability The availability of suitable substitutes for a given commodity. Reserve distribution The percentage of the world reserves located in the country with the largest reserves. Political stability of top producer A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators.

Political stability of top reserve holder A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators.

Supply risk. Relative supply risk 5. Young's modulus A measure of the stiffness of a substance. Shear modulus A measure of how difficult it is to deform a material. Bulk modulus A measure of how difficult it is to compress a substance. Vapour pressure A measure of the propensity of a substance to evaporate. Pressure and temperature data — advanced. Listen to Uranium Podcast Transcript :. You're listening to Chemistry in its element brought to you by Chemistry World , the magazine of the Royal Society of Chemistry.

For Chemistry in its element this week, can you guess what connects boat keels, armour piercing weaponry, beautiful coloured glass that you can track down with a geiger counter and more oxidation states than a chemist can shake a glass rod at. If not, here's Polly Arnold with the answer. Uranium is certainly one of the most famous, or perhaps I should say infamous, elements. It is the heaviest naturally occurring element. It is actually more abundant in the earth's crust than silver.

It is one of eight elements named in honour of celestial objects, but you might not think that uranium deserves to be named after the planet Uranus.

The lustrous black powder that the chemist Klaproth isolated from the mineral pitchblende in - just eight years after Uranus was discovered - was in fact an oxide of uranium.

Samples of the metal tarnish rapidly in air, but if the metal is finely divided, it will burst into flames.

Uranium sits amongst the actinides, the second shell of metals to fill their f-orbitals with valence electrons, making them large and weighty. Chemically, uranium is fascinating. Its nucleus is so full of protons and neutrons that it draws its core electron shells in close.

This means relativistic effects come into play that affect the electron orbital energies. The inner core s electrons move faster, and are drawn in to the heavy nucleus, shielding it better. So the outer valence orbitals are more shielded and expanded, and can form hybrid molecular orbitals that generated arguments over the precise ordering of bonding energies in the uranyl ion until as recently as this century.

This means that a variety of orbitals can now be combined to make bonds, and from this, some very interesting compounds. In the absence of air, uranium can display a wide range of oxidation states, unlike the lanthanides just above it, and it forms many deeply coloured complexes in its lower oxidation states. The uranium tetrachloride that Peligot reduced is a beautiful grass-green colour, while the triiodide is midnight-blue. Because of this, some regard it as a 'big transition metal'.

Most of these compounds are hard to make and characterise as they react so quickly with air and water, but there is still scope for big breakthroughs in this area of chemistry.

The ramifications of relativistic effects on the energies of the bonding electrons has generated much excitement for us synthetic chemists, but unfortunately many headaches for experimental and computational chemists who are trying to understand how better to deal with our nuclear waste legacy. In the environment, uranium invariably exists as a dioxide salt called the uranyl ion, in which it is tightly sandwiched between two oxygen atoms, in its highest oxidation state.

Uranyl salts are notoriously unreactive at the oxygen atoms, and about half of all known uranium compounds contain this dioxo motif. One of the most interesting facets of this area of uranium chemistry has emerged in the last couple of years: A few research groups have found ways to stabilise the singly reduced uranyl ion, a fragment which was traditionally regarded as too unstable to isolate. This ion is now beginning to show reactivity at its oxygen atoms, and may be able to teach us much about uranium's more radioactive and more reactive man-made sisters, neptunium and plutonium - these are also present in nuclear waste, but difficult to work with in greater than milligram quantities.

Outside the chemistry lab, uranium is best known for its role as a nuclear fuel. It has been at the forefront of many chemists' consciousness over recent months due to the international debate on the role that nuclear power can play in a future as a low-carbon energy source, and whether our new generations of safer and efficient power stations are human-proof. To make the fuel that is used to power reactors to generate electricity, naturally occurring uranium, which is almost all U, is enriched with the isotope U which is normally only present in about 0.

On a scale arranged according to the increasing mass of their nuclei, uranium is one of the heaviest of all the naturally-occurring elements hydrogen is the lightest. Uranium is Like other elements, uranium occurs in several slightly differing forms known as 'isotopes'.

These isotopes differ from each other in the number of uncharged particles neutrons in the nucleus. Natural uranium as found in the Earth's crust is a mixture largely of two isotopes: uranium U , accounting for The isotope U is important because under certain conditions it can readily be split, yielding a lot of energy.

It is therefore said to be 'fissile' and we use the expression 'nuclear fission'. Meanwhile, like all radioactive isotopes, they decay. U decays very slowly, its half-life being about the same as the age of the Earth million years. This means that it is barely radioactive, less so than many other isotopes in rocks and sand. Nevertheless it generates 0. U decays slightly faster. When the nucleus of a U atom captures a moving neutron it splits in two fissions and releases some energy in the form of heat, also two or three additional neutrons are thrown off.

If enough of these expelled neutrons cause the nuclei of other U atoms to split, releasing further neutrons, a fission 'chain reaction' can be achieved. When this happens over and over again, many millions of times, a very large amount of heat is produced from a relatively small amount of uranium.

It is this process , in effect 'burning' uranium, which occurs in a nuclear reactor. The heat is used to make steam to produce electricity. Nuclear power stations and fossil-fuelled power stations of similar capacity have many features in common.

Both require heat to produce steam to drive turbines and generators. In a nuclear power station, however, the fissioning of uranium atoms replaces the burning of coal or gas.

In a nuclear reactor the uranium fuel is assembled in such a way that a controlled fission chain reaction can be achieved.

The heat created by splitting the U atoms is then used to make steam which spins a turbine to drive a generator, producing electricity. The chain reaction that takes place in the core of a nuclear reactor is controlled by rods which absorb neutrons and which can be inserted or withdrawn to set the reactor at the required power level. The fuel elements are surrounded by a substance called a moderator to slow the speed of the emitted neutrons and thus enable the chain reaction to continue.

Water, graphite and heavy water are used as moderators in different types of reactor. Because of the kind of fuel used i. A typical megawatt MWe reactor can provide enough electricity for a modern city of up to one million people. Whereas the U nucleus is 'fissile', that of U is said to be 'fertile'. This means that it can capture one of the neutrons which are flying about in the core of the reactor and become indirectly plutonium, which is fissile.

Pu is very much like U, in that it fissions when hit by a neutron and this yields a similar amount of energy. Because there is so much U in a reactor core most of the fuel , these reactions occur frequently, and in fact about one-third of the fuel's energy yield comes from 'burning' Pu But sometimes a Pu atom simply captures a neutron without splitting, and it becomes Pu Because the Pu is either progressively 'burned' or becomes Pu, the longer the fuel stays in the reactor the more Pu is in it.

The significance of this is that when the spent fuel is removed after about three years, the plutonium in it is not suitable for making weapons but can be recycled as fuel. Uranium ore can be mined by underground or open-cut methods, depending on its depth. After mining, the ore is crushed and ground up. Then it is treated with acid to dissolve the uranium, which is recovered from solution.

Uranium may also be mined by in situ leaching ISL , where it is dissolved from a porous underground ore body in situ and pumped to the surface.

This is the form in which uranium is sold. Before it can be used in a reactor for electricity generation, however, it must undergo a series of processes to produce a useable fuel. Available technology and total cost must be considered when developing a mining project, and the grade of the ore must also make the project cost-effective. However most reactors require the uranium to be enriched, which means that the concentration of Uranium is increased from 0.

Enrichment of uranium allows power plants to use light water ordinary water as its coolant and moderator, since the enrichment increases the number of nuclear reactions in the reactor. After enrichment, the uranium is formed into small fuel pellets, and loaded into a fuel rod. These are assembled into fuel bundles, as seen in Figure 2. These fuel bundles are placed directly into a reactor's core, ready for fission.

Once the uranium is assembled, it can be used in a reactor to produce heat. A common misconception is that nuclear power plants magically convert their fuel directly into electricity, however their operation once the heat is generated is nearly identical to an ordinary coal-fired power plant.

Depending on the type of reactor, the heat is transferred to circulating water which boils to steam either directly i. This pressurized steam can then be used to spin a large turbine and generator , supplying electricity for the world's needs. As mentioned, the isotope Uranium is fissile. This means that it undergoes nuclear fission upon absorption of a neutron , which gives off lots of energy in the form of heat.

However, Uranium isn't the only isotope that can provide heat in a reactor. By the process of transmutation , Uranium can be converted to Plutonium through a series of beta decays. Plutonium is fissile just like Uranium, and the fissioning of it supplies additional power. Uranium has many other uses outside of its primary use in the generation of electricity.