About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
Understanding the Chemical Evolution of the ZrB2 Fuel Coating of the Integral Fuel Burnable Absorber During Irradiation |
| Author(s) |
Ronald Booth, Juliano Schorne-Pinto, Jorge Paz Soldan Palma, Kyle Johnson, Antoine Claisse, Ed Lahoda, Theodore Besmann |
| On-Site Speaker (Planned) |
Ronald Booth |
| Abstract Scope |
An alternative to solid-solution "Integral Burnable Absorbers" such as (U, Gd)O2 has been in commercial use since the mid-1980's, namely Integral Fuel Burnable Absorber (IFBA) fuel. This fuel consists of a standard UO2 pellet upon which a thin coating of ZrB2, often enriched in 10B, is applied. 10B is favored as the absorber isotope owing to its’ large (n, α) cross section. As the 10B is consumed via n + 10B = 7Li + α, the fuel undergoes burn-up and both Li and helium are generated. By approximately 15-20 MWd/kgU burnup, essentially all the 10B will be transmuted to 7Li leading to an interfacial region between the UO2 pellet and Zircaloy cladding that contains elemental Zr, liberated by the transmuting 10B, and generated Li together with residual 11ZrB2. This compares to typical high burnup fuel where the periphery is composed of a chemically and mechanically bonded rim composed of interdiffused uranium, plutonium, and zirconium oxide. Perhaps reflecting this different fuel surface composition of IFBA, post-irradiation examination of IFBA fuel revealed a major difference in fuel-cladding bonding as compared to that of conventional fuel. To help gain an understanding of the bonding behavior, a thermochemical analysis was performed in this work to determine phase formation on the fuel pellet surface of irradiated IFBA fuel. An evaluated thermodynamic database of pertinent systems in the U-Zr-B-Li-O system has been generated from available sources and used to computationally explore phase formation as a function of burn-up and composition. |
| Proceedings Inclusion? |
Undecided |