Arbitrary yes. Pick another number that is substantially larger than current share.

I am not going to be able to give statistics, but to me it's obvious. After all these decades, what's been holding nuclear down to its present market share is its economics of safety. Cost overruns all but bankrupted Toshiba, just to give one recent example.

If you want an order of magnitude more installations, you will have to relax those constraints.

So we cannot use today's safety record as proof of tomorrow's safety if we also expect massive increase in deployment.