Actinoid or actinide chemistry is a branch of nuclear chemistry. It explores pathways and molecular structures of the actinides. The chemical symbol An has been used to mention any actinides in the actinide chemistry.
Actinides are the 15 elements from 89 to 103 having atomic numbers. They are labelled for actinium, the very first element in the sequence. The class of actinides generally contains human-made elements, only with a few exceptions, such as thorium & uranium. The actinides are best known for the plutonium & uranium components that are used in nuclear bombs and reactors.
Important information about actinides
- Actinides are mostly located within the periodic table f-block
- The americium actinide is found in smoke detectors.
- Elements which have an atomic number higher than uranium (92) are sometimes referred to as transuranium, all of which are human-made under nuclear reactor circumstances.
- The first discovered actinides were uranium & thorium.
- All actinides are radioactive and none of the actinides has stable isotope.
Main Branches Of Actinide Chemistry
● Environmental and biological chemistry of actinides
In particular, consumed insoluble actinide compounds including high fired uranium dioxide & mixed oxide fuel can move with little impact into the digestive tract because they can not be dissolved and processed by the body. However, inhaled actinide substances would be more dangerous because they stay in the lungs and irradiate the tissues of the lung.
● Thermodynamic properties of Actinides
The need for accurate thermodynamic quantities for the actinide elements and compounds was recognized at the start of the Manhattan Project when a committed team of engineers and scientists began the effort to develop nuclear energy for military purposes. After the end of the 2nd World War, both fundamental and practical aims have inspired much further research of the thermodynamics of actinide.
Applications of actinides element
- Actinide is mostly used in nuclear weapons and at nuclear reactors as a fuel. The primary nuclear power isotope is uranium-235, t his isotope extensively absorbs thermal neutrons which release a lot of energy.
- Roughly half of the thorium created is used as the light-emitting component of gas mantles.
Plutonium uranium reduction extraction (PUREX)
PUREX is a chemical process used in a nuclear reactor or nuclear weapon fuel purification. The method for extracting uranium and plutonium from spent nuclear fuel dependent on liquid-liquid extraction ion-exchange. PUREX is implemented to spend nuclear fuel, which mainly consists of really high atomic-weight elements such as uranium, plutonium, americium along with smaller quantities of material consisting of smaller elements, particularly called fission products.
The chemical procedure involved in PUREX
The fuel is diluted in HNO3 (nitric acid) at a concentration of ca. 7 M. Solids are extracted by filtration method and they develop emulsions, related to in the solvent extraction group as the third phase. The organic solvent comprises 30 percent TBP (tributyl phosphate) in kerosene which is a hydrocarbon. Uranium ions are released as complexes of [UO2(NO3)2·2TBP] and plutonium as complexes of similar type.
Plutonium is isolated from uranium by using reducing agents to treat the kerosene solution to convert the plutonium to +3 oxidation state and Plutonium +3 goes to the phase of aqueous. The uranium is extracted from the kerosene by the method of back extraction into HNO3 at a concentration of ca. 0.2M.