ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Apr 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
May 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Glass strategy: Hanford’s enhanced waste glass program
The mission of the Department of Energy’s Office of River Protection (ORP) is to complete the safe cleanup of waste resulting from decades of nuclear weapons development. One of the most technologically challenging responsibilities is the safe disposition of approximately 56 million gallons of radioactive waste historically stored in 177 tanks at the Hanford Site in Washington state.
ORP has a clear incentive to reduce the overall mission duration and cost. One pathway is to develop and deploy innovative technical solutions that can advance baseline flow sheets toward higher efficiency operations while reducing identified risks without compromising safety. Vitrification is the baseline process that will convert both high-level and low-level radioactive waste at Hanford into a stable glass waste form for long-term storage and disposal.
Although vitrification is a mature technology, there are key areas where technology can further reduce operational risks, advance baseline processes to maximize waste throughput, and provide the underpinning to enhance operational flexibility; all steps in reducing mission duration and cost.
Egon Vietzke, Volker Philipps
Fusion Science and Technology | Volume 15 | Number 1 | January 1989 | Pages 108-117
Technical Paper | doi.org/10.13182/FST89-A25333
Articles are hosted by Taylor and Francis Online.
The hydrocarbon formation of carbon materials exposed to hydrogen atoms and ions is reviewed. It turns out that surface conditions and modification play a major role in hydrocarbon formation. Graphite exposed to hydrogen plasma exhibits surface properties similar to those of amorphous hydrogenated carbon films and redeposited carbon films. The total chemical erosion yield of these carbon materials is similar for thermal atomic hydrogen and for energetic hydrogen ions, reaching maximum values of ∼0.1 eroded carbon per incoming hydrogen. However, the spectrum of formed hydrocarbons is determined by the energy of the impinging hydrogen. By a thermal H0 exposure, CH3 is formed together with equal amounts of C2Hx and C3Hx. With an energetic H+ bombardment, the main reaction product is CH4 with minor contributions of C2Hx and C3Hx. The amount of C2Hx and C3Hx formation decreases with increasing H+ energy. Hydrocarbon formation at low energies and high flux densities, as in the scrape-off layer (SOL) of fusion devices, is characterized by a broadening of the temperature dependence together with a slight decrease of the absolute erosion yield. Similar results have been obtained by an in situ study of the hydrocarbon formation in the SOL of the Tokamak Experiment for Technology Oriented Research (TEXTOR) plasma using a sniffer probe system.