Modeling the Fission Landscape of Uranium Isotopes via Constrained Nuclear DFT: Toward Multiscale Fuel Behavior Prediction

We are developing a computational framework to model the fission pathways of ²³⁶U and ²³⁹U—formed via thermal and fast neutron capture, respectively—using the nuclear Density Functional Theory code HFODD, which solves the Hartree-Fock-Bogoliubov equations in a fully three-dimensional Cartesian deformed basis. By systematically applying constraints on quadrupole (Q20) and octupole (Q30) moments, we are generating potential energy surfaces (PES) that span both axial and reflection-asymmetric deformations. For ²³⁶U, we expect to observe features of multimodal fission and distinct scission pathways, consistent with prior studies, that may help explain observed asymmetries in fragment mass yields. These calculations are ongoing and will be extended to ²³⁹U to probe the impact of higher excitation energy on fission dynamics and to develop approaches for handling odd-A nuclear systems. In parallel, we are exploring whether NDFT-derived nuclear densities and deformation-dependent mean fields could inform improved pseudopotential formulations for parent and fragment ions (e.g., U, Xe, Zr). This work aims to bridge nuclear structure and fission dynamics with emergent materials behavior relevant to fuel performance.