My belief is that Alligator River is about a future for VMY AFTER Mulga Rock, Mulga Rock has ~15 year mine life, so the (theoretical) ten plus years to have Alligator River production ready, fits fine.
However, and something I've never fully understood, Cameco has a buy back right if VMY makes a large discovery (>100mlbs?), but buy back on what terms we (I) don't know.
So I don't think it's essential for VMY to be able to prove that it has production capacity to supply after Mulga Rock, it should be enough that it is out there with highly prospective ground, working towards continuing supply capability.
B22.