Depleted uranium, in these designs, is used for the ballast in the middle of the missile, for flight stability. Uranium, however, is used for the reactive material. Reactive materials are a way to increase lethality of the missile by « up to a factor of five » according to weapons makers. Indeed they introduce oxydation at the explosion of the missile. This means pyrophoricity. It has been acknowledged that combustion of uranium weapons produces temperatures of up to 5000°C, which seems to be the highest temperature produced by a non-nuclear explosion recorded on Earth.
To quote both patents, from the US Navy,
As is known in the art, reactive composite materials generally include particles or powdered forms of one or more reactive metals, one or more oxidizers, and typically some binder materials. The reactive metals can include aluminum, beryllium, hafnium, lithium, magnesium, thorium, titanium, uranium, zirconium, as well as combinations, alloys and hydrides thereof
As you can see, nowhere it is mentioned « depleted » uranium, but only « uranium », demonstrating thus that this uranium is not intended to be depleted.
Indeed this actually makes sense, because pyrophoricity of uranium is dependent on its radioactivity : the more radioactive, the more pyrophoric, because alpha radioactivity means internal heat for the metal, and thus ability to oxidise easily. The presence of isotopes such as 234U, and probably of plutonium too, increases radioactivity and thus ability to burn.
But it is interesting to have here, clearly, confirmation that uranium for reactive materials is not depleted. See links above and research by Dr. Asaf Durakovic who demonstrated that the uranium found in Iraq is more radioactive than depleted uranium. Hence, there are non-depleted uranium weapons (call them simply uranium weapons !) that work with non-depleted uranium, everytime there is a need for pyrophoricity (and as I said pyrophoricity increases lethality by « up to a factor of five »). This is especially required for shaped charge weapons and similar designs – e.g. squash head.
Another older patent for an armor-piercing incendiary projectile mentions the use of uranium without calling it « depleted « uranium », it seems the same conclusions can be drawn from it. This munition would burn unto impact, it needs no explosive charge to trigger the flame, demonstrating that non-depleted uranium also increases the effet of kinetic energy penetrators.
It perfectly makes sense in this context that some weapons have actually been designed with plutonium for the same incendiary effect as described above. Plutonium is just another « reactive material » with high density and pyrophoricity, but it’s even more toxic than uranium – the most toxic element on Earth actually. Its use not only is criminal, but is a door opened to nuclear proliferation…