11/1/2004 Nicholas Sharp
The subfield of chemistry known as nuclear chemistry deals with phenomena associated with the atomic nucleus. This includes radioactivity, radiation, and other nuclear processes and properties1, 2. Types of nuclear chemists include isotopic chemists, radiochemists, NMR (nuclear magnetic resonance) chemists, and different types of nuclear technologist3, 4.
Isotopic chemists study the effects of different nuclear masses on atoms or compounds and their reactions5, 6. For example, ordinary water (diprotium monoxide) has a melting point of 0°C and a boiling point of 100°C, while heavy water (dideuterium monoxide) has a melting point of 3.82°C, and a boiling point of 101.42°C7. As one can see, heavier isotopes of hydrogen in water (dihydrogen monoxide) have elevated melting and boiling points. One of an isotopic chemist’s jobs is to separate isotopes. This is very important when one is separating uranium-235 from uranium-238 for use in nuclear explosives and reactors.
Radiochemists study radiation and different types of radioisotopes. Radiation is used for medical purposes by radiologists. PET (positron emission tomography) scans use glucose molecules tipped with positron-emitting radioactive tracers to identify, for example, what parts of the brain metabolize the glucose the most8. It is also used heavily in oncology9. Radiochemists work closely with health physicists and radiologists. They also study the chemical effects of high-energy radiation on atoms and compounds.
NMR spectrometers are used by analytic chemists and biochemists to determine the physical, chemical, and electronic properties of molecules10. NMR is also used in MRI (magnetic resonance imaging)11. Magnetic resonance imaging has the advantage of being completely harmless to the patient as compared to other, more harmful, imaging techniques (such as CAT scans or x-rays)12.
Nuclear chemists are also found working with a number of nuclear-related technologies. Fission, the phenomenon of splitting heavy nuclei such as of uranium or plutonium with neutrons, is used in many different ways, from nuclear explosives to nuclear reactors. In a nuclear explosion, uranium or plutonium is fissioned to the point of a chain reaction. If one has a critical mass of uranium or plutonium, the exponential releasing of energy leads to a nuclear explosion. In a nuclear reactor, a similar principle is used, except that one tries to avoid obtaining a critical mass and a runaway chain reaction. Nuclear chemists must know the dangers of radiation from nuclear reactors and fallout from nuclear explosions. One of the products of radioactive fallout is strontium-90, which replaces the calcium in bones. Another area in which nuclear chemists are used is in nuclear fusion. Nuclear fusion occurs in the hearts of stars, supernovae, thermonuclear explosions, and in man-made fusion reactors. One of today's quests includes a search for a stable, self-sustaining fusion reaction. Fusion has been maintained for a few brief moments (producing sixteen megawatts) at the JET (Joint European Torus) tokamak in 199713. The proposed ITER (International Thermonuclear Experimental Reactor) would cost about ten billion US dollars and would produce a continuous power of approximately five hundred megawatts14.
Another area where nuclear chemists actually perform the "chemistry of the nucleus" is in the production of new elements. Over the years, many superheavy transuranic elements have been constructed and discovered. These are from neptunium (1940)15 to ununtrium and ununpentium (2004)16. These elements are constructed by colliding different elements to form the new elements.
As of 2002, there were 16,000 nuclear engineers in the United States17. There is little or no growth expected of this occupation in the United States till 2012, for the number of people entering the profession equals the number of people leaving it18. In 2002, median annual income for a nuclear engineer was $81,35019.
Nuclear chemists often work in teams in laboratories20. They use computers and simulation programs21. It is extremely important that they apply nuclear safety regulations at all times22. They often wear thermoluminescent dosimeters and sometimes protective clothing when working in possibly radioactive areas23. Nuclear chemists and engineers need to have good physical mobility, eyesight, and hearing to do their job24. Sometimes their job is stressful due to all of the safety concerns they have to deal with25.