News Article: Harnessing the Power of Man-Made Elements: Transuranium Elements
The pursuit of new chemical entities
In the realm of scientific discovery, the creation of elements beyond uranium (atomic number 92) – known as transuranium elements – has opened up a world of possibilities. These elements, artificially produced through nuclear reactions, have found their way into various applications, particularly in the generation of electricity and space exploration.
Methods of Production
Scientists employ a variety of methods to create transuranium elements. Neutron bombardment, where elements are exposed to a high flux of neutrons in a nuclear reactor, is one such method. Neutrons induce nuclear reactions that can lead to the formation of heavier elements when absorbed by atomic nuclei. For example, plutonium is produced by bombarding uranium-238 with neutrons, followed by radioactive decay [4][5].
Another method involves the use of particle accelerators. These machines can accelerate charged particles like alpha particles or protons to high speeds, allowing them to collide with target nuclei. These collisions can result in the formation of new elements by adding protons or neutrons to the target nuclei. For instance, berkelium is produced by bombarding americium with alpha particles [3][5].
Radioactive decay processes also play a role in the creation of some transuranium elements. After the initial formation of a new element through neutron bombardment or particle collisions, it may undergo radioactive decay to form another element [5].
Step-by-Step Synthesis Example: Curium
The production of curium, for instance, begins with plutonium or americium. After irradiation in a high-flux reactor, complex chemical separation processes are used to isolate curium from other reaction products [2].
Challenges and Applications
The production of transuranium elements is fraught with challenges due to the complexity of the processes involved and the extreme radioactivity of these elements. However, their unique properties have found uses in niche areas.
In the realm of power generation, suitable radionuclides for radionuclide power sources need to be easily shielded, emit weakly penetrating radiation, have reasonably long half-lives, be corrosion-resistant, insoluble in water, cheap, and readily available. These sources are used in space applications such as remote sensing, communication satellites, and deep space missions, where their high power density is beneficial [2].
Nuclear fuel assemblies contain enriched uranium dioxide pellets packed into corrosion-resistant metal alloy tubes. Despite the challenges, the importance of these elements, particularly uranium and the transuranium elements, in the generation of electricity in nuclear power plants cannot be overstated.
Plutonium, a radioactive poison, requires careful handling. It tarnishes in air to form a yellow oxide. However, its unique properties make it a valuable resource in the field of nuclear energy.
The discovery of new elements continues at many research labs around the world, further expanding our understanding of the universe and opening up new possibilities for practical applications. Science, with its social and cultural embeddedness, is affected by various cultural elements such as political and economic factors, shaping the direction of research and development in this field.
[1] Glenn Seaborg, a prominent chemist, had an element named after him – seaborgium (Sg). Seaborg, a scientist at the Lawrence Berkley Laboratory, discovered 9 additional transuranium elements (americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and seaborgium) between 1944 and 1974.
[2] Syntheses reactions for seaborgium and mendelevium are Sg Cf O → Sg + 4n and Md Es He → Md + n, respectively.
[3] Plutonium-238 and curium-245 are radioactive and emit decay energy that can be absorbed in a suitable material, giving rise to heat.
[4] These elements, known as transuranium elements, only last for a short time before decomposing.
[5] Radiation levels from the fuel rods prior to their use are negligible, so no shielding is required.
1. The production of transuranium elements, such as plutonium and curium, often involves neutron bombardment or particle collisions in a high-flux reactor, a method that has proven effective in generating electricity and aiding in space exploration.
2. In the realms of power generation and space exploration, the unique properties of transuranium elements, particularly their ability to emit weakly penetrating radiation and their high power density, make them essential for niche applications such as remote sensing and deep space missions.
