Hi there RAZD, I would like you to address these issues please...
Uranium halos are not evidence for an old Earth because they are based on two assumptions you don't know anything about. So let's take it step by step...
1.) Half life of U238.
2.) Halo itself.
1.) The claim that U238 half-life is 4.5 billion years. How do you know that? Where has this been shown to be true? You don't know that. You assume that. And since you don't know it, you don't know that it took 4.5 billion years to make ANY U238 halo. Even if, I repeat, even if, there was no accelerated alpha decay. You still wouldn't have any evidence for an old Earth. Why? Well because you don't know the half-life of the U238 to begin with. You never saw it form. You didn't, nor did anyone else I presume, stand there for 4.5 billion years and observe the U238 halo form. Since you never observed it form, you don't know it's half-life.
2.) And the second assumption, which is even worse. Is the assumption that the U238 halo was produced by a constand decay rate. And then you turn and say that since it was constant decy, it had constant energy, thus a specific halo was formed that can only be produced by constant energy. That's circular logic. Since you don't know by what energy strength was that halo formed, you don't know if it was formed by constant decay, and of course constant energy. And you don't know that, because you never saw a U238 halo form, and what energy it took to form the said halo, that you never saw form in the first place.
In conclusion...
a.) You don't know the half-life of Uranium 238.
b.) You don't know what energy and decay rates it takes to form a Uranium 238 halo.
c.) For any Uranium 238 halo you see, you don't know if it was formed by a constant rate of decay and energy, because you never observed them form in the first place.
d.) Therefore Uranium 238 halos do not have to be 4.5 billion years old.
e.) Therefore Uranium 238 halos do not have to be produced by constant decay rate and energy strength.
f.) Therefore Uranium 238 halos are not evidence for an old Earth.