IMO you could afford to build high tech self sustaining enviroment for <50k people easily, a few micro nuclear reactors [1] would provide enough electricity, hydroponics, seafood farming, or advanced things like protein from bacteria/algae protein for food production, import the luxuries. They seem to have drinkable fresh water source, and with enough power and cash desalination is viable.
The fantasy business model would be to be rich enough to be able to personally cover these costs and establish a high tech R&D environment :) I'm not suggesting that this is actually possible, it's one of those things - what would I do if I had Bill Gates kind of money.
This sounds like an extremely high-cost environment. How would you compete with high tech R&D centers around the world that may have 1/10th or 1/100th the costs? I'm not saying you can't compete, but I think you'd have to offer something (1) that you couldn't get anywhere else but Nauru and (2) is in very high demand.
(And by the way, not trying to rain on your parade; on the contrary, I find this discussion fascinating, so thanks for starting it.)
You'd be fine. Just let the inspectors in and be super-transparent. Plenty of people have research reactors, and if you aren't a belligerent theocracy, you shouldn't have much of a problem. Just play nice.
Micro nuclear reactors don't have weapons grade uranium/plutonium in large quantities, AFAIK at best they could be used to build a dirty bomb. And what would be the point of that ? I'm not proposing building a religious sect, just a society of hand picked individuals from different fields, like engineering, natural sciences, architecture, arts etc.
My undergraduate institution (Reed College) has a student operated nuclear reactor on campus. No weapons grade nuclear material, and it wouldn't make a very good dirty bomb either. However, it's useful for bombarding things with neutrons and it does give off a pretty blue light because of Cherenkov radiation: http://en.wikipedia.org/wiki/Reed_Research_Reactor.
Given Nauru's isolation and exposure to the elements, I'd
rather install a couple 7.5MW Enercom wind turbines, a few
MW worth of solar panels and maybe a tidal generator instead
of a nuclear reactor.
The fantasy business model would be to be rich enough to be able to personally cover these costs and establish a high tech R&D environment :) I'm not suggesting that this is actually possible, it's one of those things - what would I do if I had Bill Gates kind of money.
[1] http://en.wikipedia.org/wiki/Toshiba_4S