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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
Latest News
Remembering ANS member Gil Brown
Brown
The nuclear community is mourning the loss of Gilbert Brown, who passed away on July 11 at the age of 77 following a battle with cancer.
Brown, an American Nuclear Society Fellow and an ANS member for nearly 50 years, joined the faculty at Lowell Technological Institute—now the University of Massachusetts–Lowell—in 1973 and remained there for the rest of his career. He eventually became director of the UMass Lowell nuclear engineering program. After his retirement, he remained an emeritus professor at the university.
Sukesh Aghara, chair of the Nuclear Engineering Department Heads Organization, noted in an email to NEDHO members and others that “Gil was a relentless advocate for nuclear energy and a deeply respected member of our professional community. He was also a kind and generous friend—and one of the reasons I ended up at UMass Lowell. He served the university with great dedication. . . . Within NEDHO, Gil was a steady presence and served for many years as our treasurer. His contributions to nuclear engineering education and to this community will be dearly missed.”
Hee Su Choe, Geon-Woo Kim, Hyoung Kyu Cho, Goon-Cheryl Park, Kihak Im (Seoul Natl Univ)
Proceedings | 2018 International Congress on Advances in Nuclear Power Plants (ICAPP 2018) | Charlotte, NC, April 8-11, 2018 | Pages 965-971
Under high heat flux, upset or high power conditions due to several reasons, the components in various engineering applications can be damaged and its structural materials may undergo phase change such as melting and evaporation, making it difficult to maintain the integrity. Plasma transients such as vertical displace events, plasma disruption, runaway electron, etc. that may occur in a tokamak fusion reactor can be a relevant example. Plasma facing components (PFCs) can be exposed to high heat flux conditions and damaged if it occurs and therefore, thermal-hydraulic safety analysis to predict the behavior of reactor elements and structural components under high heat flux conditions is required. In this study, one-dimensional thermal-hydraulic analysis under material phase change conditions was conducted in the blanket first wall module of the Korean fusion demonstration reactor (K-DEMO). In order to simulate the melting and evaporating phenomenon, effective heat capacity method (EHCM) and Hertz-Knudsen-Langmuir theory of evaporation and condensation are used, respectively. At first, the flux of atoms leaving the surface of evaporating phase and the velocity of the receding surface were derived from the evaporation theory. Afterwards, EHCM modifies the effective heat capacity using the latent heat of fusion of the target material. However, this method has a distinctive disadvantage in convergence on mesh sizes and mushy zone sizes leading to distortion of the prediction results and lower numerical efficiency under rapid transient events. For this reason, a mesh adaptation technique using tracking the material phase change temperature (melting point) and the damaged depth (melting and evaporation depth) was implemented to the phase change calculation module to improve the calculation capability under diverse high heat flux conditions. An appropriate monitoring function for tracking the phase change temperature was selected and the re-meshing procedure was proceeded resulting in smaller meshes concentrated at the melting interface. As the mesh adaptation technique was applied to the EHCM, its numerical efficiency was improved and dependency on mesh size and required mushy zone size was decreased. For the validation of the melting model, Stefan’s problem was selected as a conceptual problem and the calculation results were compared with analytic solution for the code to code comparison. Then, the phase change calculation module involving both melting and evaporating simulations was coupled with the nuclear reactor safety analysis code, MARS to analyze the thermal-hydraulic behavior of the water cooled breeding blanket in KDEMO under several high heat flux conditions.
