Nuclear chemistry
An important area is the behavior of objects and materials after being placed into a nuclear waste storage or disposal site.
It includes the study of the chemical effects resulting from the absorption of radiation within living animals, plants, and other materials.
These include radiotherapy in medical applications; the use of radioactive tracers within industry, science and the environment, and the use of radiation to modify materials such as polymers.
Marie Skłodowska-Curie (working in Paris) and her husband Pierre Curie isolated two new radioactive elements from uranium ore.
To Rutherford, the gold foil experiment implied that the positive charge was confined to a very small nucleus leading first to the Rutherford model, and eventually to the Bohr model of the atom, where the positive nucleus is surrounded by the negative electrons.
[4] Hahn and Lise Meitner discovered radioactive isotopes of radium, thorium, protactinium and uranium.
Using a X-ray generator, Hugo Fricke studied the biological effects of radiation as it became a common treatment option and diagnostic method.
President Jimmy Carter issued a Presidential directive which indefinitely suspended the commercial reprocessing and recycling of plutonium in the United States.
This directive was likely an attempt by the United States to lead other countries by example, but many other nations continue to reprocess spent nuclear fuels.
It is normal to dissolve the used fuel in nitric acid, after the removal of the insoluble matter the uranium and plutonium are extracted from the highly active liquor.
It is normal to then back extract the loaded organic phase to create a medium active liquor which contains mostly uranium and plutonium with only small traces of fission products.
The dibutyl hydrogen phosphate can make the system behave in a more complex manner as it tends to extract metals by an ion exchange mechanism (extraction favoured by low acid concentration), to reduce the effect of the dibutyl hydrogen phosphate it is common for the used organic phase to be washed with sodium carbonate solution to remove the acidic degradation products of the tributyl phosphatioloporus.
The DIAMEX (DIAMideEXtraction) process has the advantage of avoiding the formation of organic waste which contains elements other than carbon, hydrogen, nitrogen, and oxygen.
In order to allow the actinides such as americium to be either reused in industrial sources or used as fuel the lanthanides must be removed.
[20] Another important area of nuclear chemistry is the study of how fission products interact with surfaces; this is thought to control the rate of release and migration of fission products both from waste containers under normal conditions and from power reactors under accident conditions.
Like chromate and molybdate, the 99TcO4 anion can react with steel surfaces to form a corrosion resistant layer.
It has also been shown that 99TcO4 anions react to form a layer on the surface of activated carbon (charcoal) or aluminium.
[21][22] A short review of the biochemical properties of a series of key long lived radioisotopes can be read on line.
[24] Similarly, the release of iodine-131 in a serious power reactor accident could be retarded by absorption on metal surfaces within the nuclear plant.
Now, with many experts in these fields approaching retirement age, action is needed to avoid a workforce gap in these critical fields, for example by building student interest in these careers, expanding the educational capacity of universities and colleges, and providing more specific on-the-job training.
In Europe, as substantial effort is being done to harmonize and prepare the NRC education for the industry's and society's future needs.
[31][32] Although NucWik is primarily aimed at teachers, anyone interested in nuclear and radiochemistry is welcome and can find a lot of information and material explaining topics related to NRC.
This can lead to a decrease in the reaction rate if the rate-determining step involves breaking a bond between hydrogen and another atom.
Within living things, isotopic labels (both radioactive and nonradioactive) can be used to probe how the complex web of reactions which makes up the metabolism of an organism converts one substance to another.
For instance a green plant uses light energy to convert water and carbon dioxide into glucose by photosynthesis.
For biochemical and physiological experiments and medical methods, a number of specific isotopes have important applications.
NMR spectroscopy uses the net spin of nuclei in a substance upon energy absorption to identify molecules.
This is widely used for diagnostic purposes in medicine, and can provide detailed images of the inside of a person without inflicting any radiation upon them.
In a medical setting, NMR is often known simply as "magnetic resonance" imaging, as the word 'nuclear' has negative connotations for many people.
