Depleted uranium is used in armor piercing tank shells, armor piercing autocannon rounds, and bunker buster bombs. The high density of Uranium helps with penetration. Depleted uranium is commonly used for that purpose. Tungsten is a more expensive and slightly worse alternative used by other countries.

We know the Israeli Air Force used bunker buster bombs to kill Nasrallah in his bunker, possibly BLU-109.

So this whole story is certainly plausible.