And the way for this to happen is for people who want it to happen to start their own companies to do it. That's how free market competition works: if there is a genuine market need that is not being filled, someone starts a new company to fill it. You don't sue existing companies.

In the case of fossil fuels, this already is happening; there are plenty of companies working on alternative sources of energy. (And the "Big Oil" companies are among them.) As far as using government and the law to help, the single biggest impact ordinary people can have is to make it clear to our elected representatives that nuclear energy is a thing and we need more of it.