A dimensioning study on electric vehicle batteries as components of a post nuclear detonation radiological environment

Understanding the neutron activation of modern urban materials following a nuclear detonation is important for effective emergency rescue and response planning, yet neutron-activation data for contemporary infrastructure remain limited. This study presents a dimensioning assessment of neutron-induced activation in electric vehicle (EV) battery systems, an increasingly common high-mass, high-metal component of modern cities. Using detailed Monte Carlo simulations, supported by controlled activation experiments with a thermalized neutron field, the activation products and resulting dose rates for three major battery chemistries (NMC-811, NCA, and LFP) arranged in a representative battery pack, were evaluated. Results show that EV batteries can generate substantial short-lived gamma activity immediately after neutron exposure, dominated by 28 Al, 64 Cu and 56 Mn for nickel- and cobalt-bearing chemistries, while long-term activity is driven primarily by 60 Co (NMC/NCA) and 32 P (LFP). Dose rate estimations indicate that elevated fields may be present during the first hours post-detonation but decrease by several orders of magnitude within 24 h. Comparisons with activation of urban road materials reveal that 24 Na generated in asphalt and sand substrates can equal or exceed battery-derived dose contributions. Overall, EV batteries constitute a relevant but transient localized radiological hazard in the immediate aftermath of a nuclear detonation, with significance highly dependent on battery chemistry and the timing of response operations. These findings support improved modelling of post-detonation environments and help contextualize EV batteries within broader urban activation scenarios.