Clandestine means secrete and illegal. If it was secret, how do you know about it and if it was illegal, what was illegal about it?

Bill Gates famously funded a "mini-nukes" company to make smaller footprint nuclear power plants, and portable nuclear generators.

So what? Where is the connection to a smaller nuclear reactor coming from?

"so what" is up to you.. maybe it means nothing to you, "so what"

It means nothing to me, what was the point you were trying to make?