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.
Explore membership for yourself or for your organization.
Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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
Sep 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
October 2025
Latest News
Empowering the next generation: ANS’s newest book focuses on careers in nuclear energy
A new career guide for the nuclear energy industry is now available: The Nuclear Empowered Workforce by Earnestine Johnson. Drawing on more than 30 years of experience across 16 nuclear facilities, Johnson offers a practical, insightful look into some of the many career paths available in commercial nuclear power. To mark the release, Johnson sat down with Nuclear News for a wide-ranging conversation about her career, her motivation for writing the book, and her advice for the next generation of nuclear professionals.
When Johnson began her career at engineering services company Stone & Webster, she entered a field still reeling from the effects of the Three Mile Island incident in 1979, nearly 15 years earlier. Her hiring cohort was the first group of new engineering graduates the company had brought on since TMI, a reflection of the industry-wide pause in nuclear construction. Her first long-term assignment—at the Millstone site in Waterford, Conn., helping resolve design issues stemming from TMI—marked the beginning of a long and varied career that spanned positions across the country.
N. Bekris, M. Sirch
Fusion Science and Technology | Volume 62 | Number 1 | July-August 2012 | Pages 50-55
Hydrogen/Tritium Behavior | Proceedings of the Fifteenth International Conference on Fusion Reactor Materials, Part A: Fusion Technology | doi.org/10.13182/FST12-A14111
Articles are hosted by Taylor and Francis Online.
Among the various getter materials the interalloy ZrCo has been selected by the ITER team as the reference material for the storage of hydrogen isotopes at the tritium plant because of its excellent getter properties, which are comparable to those of uranium. Only certain conditions, such as the presence of high partial pressure of H2 at relatively low temperatures (350°C to 400°C), or during repeated hydrogen absorption-desorption heat cycles, have been a matter of concern, because under these conditions ZrCo can lose its gettering properties. Indeed, under repetitive loading/deloading cycling, the getter hydride (ZrCoH3) tends to disproportionate, i.e., to convert into ZrH2 and ZrCo2 and thus show a significant performance degradation of its gettering properties. Disproportionation is a major drawback as it fixes almost irreversibly part of the hydrogen (hence, tritium) into a ZrH2 form.To understand the underlying mechanism leading to the disproportionation, a detailed investigation has been undertaken. Using thermal analytical methods and based on crystallographic considerations, we came to the conclusion that the driving force for such disproportionation has to be attributed to the hydrogen occupation (taking place during the hydridation) of the various crystallographic sites available to it. During the hydridation process [approximately]4% of hydrogen goes into the less-stable 8f2 and 8e sites, where the Zr-H distance is shorter than the ZrH2 distance. Therefore, during the dehydridation process these sites are not releasing the hydrogen, but rather they are generating the very stable ZrH2, thus leading to the partial disproportionation of the material.Therefore, we may conclude that ZrCo it is not adequate for the storage of tritium and other hydrogen isotopes within the tritium plant of ITER, and consequently, we would not recommend it for such use.