[peter_m1]

That would be a quantum Turing Machine as radioactivity is a quantum process.

[RandomLensman]

How would that work as current understanding from quantum theory is that we cannot predict which atom decays next? Is there a quantum algorithm that can do that?

[GoblinSlayer]

The decay process is calculated as

sqrt(1-exp(-t/T))|1> + sqrt(exp(-t/T))|0>

[RandomLensman]

How do you use that to predict which atom decays next?

[GoblinSlayer]

The decayed state exists, it's the second term sqrt(exp(-t/T))|0>

[RandomLensman]

How do you predict which atom decays next from there?

[GoblinSlayer]

Since the decayed state exists, then any. Your question tries to assume sqrt(exp(-t/T))=0, which is false.