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
Oct 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
November 2025
Nuclear Technology
October 2025
Fusion Science and Technology
Latest News
NEA report calls for more accurate data on SNF heat decay
The OECD Nuclear Energy Agency has issued a report calling for more-detailed information on tracking the decay heat of spent nuclear fuel from light water reactors. According to the NEA, the report highlights the increasing importance of accurate decay heat estimations due to evolving fuel characteristics, including higher initial fuel enrichment, increased burn-up rates, and extended reactor cycle lengths.
The report, Summary of the NEA Assessment on Spent Nuclear Fuel Decay Heat for Light Water Reactors, summarizes the findings of a subgroup of the NEA’s Working Party on Nuclear Criticality Safety (WPNCS), which ran from January 2022 to January 2024.
N. A. P. Kiran Kumar, K. J. Leonard, G. E. Jellison, L. L. Snead
Fusion Science and Technology | Volume 67 | Number 4 | May 2015 | Pages 771-783
Technical Paper | doi.org/10.13182/FST14-875
Articles are hosted by Taylor and Francis Online.
The study presents the high-dose behavior of dielectric mirrors specifically engineered for radiation tolerance. Alternating layers of Al2O3/SiO2 and HfO2/SiO2 were grown on sapphire substrates and exposed to neutron doses of 1 and 4 displacements per atom (dpa) at 458 ± 10 K in the High Flux Isotope Reactor (HFIR). In comparison to previously reported results, these higher doses of 1 and 4 dpa result in a drastic drop in optical reflectance, caused by a failure of the multilayer coating. HfO2/SiO2 mirrors failed completely when exposed to 1 dpa, whereas the reflectance of Al2O3/SiO2 mirrors reduced to 44%, eventually failing at 4 dpa. Transmission electron microscopy (TEM) observation of the Al2O3/SiO2 specimens showed SiO2 layer defects, which increase in size with irradiation dose. The typical size of each defect was ≈8 nm in 1-dpa specimens and ≈42 nm in 4-dpa specimens. Buckling-type delamination of the interface between the substrate and first layer was typically observed in both 1- and 4-dpa HfO2/SiO2 specimens. Composition changes across the layers were measured in high-resolution-scanning–TEM mode using energy dispersive spectroscopy. A significant interdiffusion between the film layers was observed in the Al2O3/SiO2 mirror, although it was less evident in the HfO2/SiO2 system. The ultimate goal of this work is to provide insight into the radiation-induced failure mechanisms of these mirrors.
