Which is NOT a way CBRN reconnaissance teams can be exposed to depleted uranium?

Working on standard military vehicles is not a way CBRN reconnaissance teams can be exposed to depleted uranium. This is because standard military vehicles typically do not contain depleted uranium unless they are specifically designed or modified for that purpose, such as certain armored vehicles which may use depleted uranium as part of their construction for its density and effectiveness in armor-piercing capabilities.

In contrast, patrols discovering DU contamination, handling DU munitions, and vehicle operators in armored vehicles are all scenarios that present a risk of exposure. Patrols might encounter areas contaminated with depleted uranium during reconnaissance missions, while handling DU munitions directly exposes personnel to the material. Similarly, vehicle operators in armored vehicles may be at risk if those vehicles incorporate depleted uranium in their design. Therefore, the option concerning standard military vehicles correctly identifies a scenario where there is no risk of exposure to depleted uranium.