The "unlimited" range comes because the thing is powered by a nuclear reactor, which would run out of fuel eventually but not before reaching any point you want

The "unlimited" range comes because the thing is powered by a nuclear reactor, which would run out of fuel eventually but not before reaching any point you want on Earth first. So it doesn't have a limited range in the normal sense of "how far away can I hit something?"- the answer is, as far away as you like.