They're working on policy for extending life while simultaneously creating rules for next-gen plants (e.g. NuScale, TerraPower).
It's weird to me that more energy companies haven't gone Bitcoin first, like simultaneously deploying Bitcoin at a new energy site as backup for over supply situations. There's no reasonable explanation for it happening soon or ever, but imagine if the policies that Japan was working on forced contingencies for oversupplied situations for new power generation projects. This sort of policy would be especially applicable for Japan considering how much the population is supposed to decline in the next 20-30 years.