First "Wind and Solar" doesn't have a single failure mode. You're now looking for failures of multiple days with minimal wind and high cloud cover if you want to invoke a "catastrophe" per the upthread phrasing. And that's much harder to do, statistically.

It also discounts that "majority of the grid" doesn't mean "without backup/storage solutions". Those gas plants aren't going away, they're just going to end up mothballed as (to be fair, very expensive) peaker plants. People are working hard on storage solutions like batteries and pumped hydro, wider grid connectivity for cross-continent buffering, etc...

It's totally a solvable problem (quite frankly it's significantly more solvable than "nuclear is an order of magnitude too expensive", which is the real thing holding reactors back). There will be no "catastrophes" in a renewable-driven grid, there just won't.

So please stop with the FUD, and stop reading sources that are feeding it to you. Nuclear has a place in the world, but it has to get its act together and compete in the market. You can't just argue that its competitors won't work, because it's wrong.