Just because something has been “tried before” in the past for something as critical as energy sustainability, particularly with the backdrop of climate change, doesn’t mean we shouldn’t try it again. If anything it puts us in a better position, with grater knowledge, in order to improve are chances of making it work.
As Edison put it about trying to invent the lightbulb: “I haven't failed - I've just found 10,000 that won't work”.
Interestingly, this whole technology might come to market more quickly than a nuclear reactor in an industrialized country could be build from decision to commercial operation.
At best, nuclear power is unwieldy, hard to calculate, needs a vast, highly specialized infrastructure and workforce and leaves you with radioactive waste with no solution realized as of yet. At worst, "impossible" accidents happen, people shoot at your reactor, nation states devolve and use the fuel for dirty bombs, somebody tries to blow the reactor up on purpose...
Just like we already had the “lightbulb” in the form of candles. There are significant downsides to nuclear reactors that other kinds of sustainable power might be able to address
As Edison put it about trying to invent the lightbulb: “I haven't failed - I've just found 10,000 that won't work”.