People talk about failures of the market all the time, and there are many. This was one of the failures of regulation.

I think we're starting to see a small revival here finally, but is it too late? Renewables are driving down the cost of electricity so any nuclear companies not only have to find a way to be profitable today, but 1, 2, 3 decades from now.

The problem with nuclear fission will always be the moments when somebody “should” have done a safety test or should have thought about it.

I often think about the reaction Angela Merkel had to the Fukushima incident. Before the Tsunami she had just scrapped the plan to end nuclear in Germany. She is a trained research physicists so that is the position you would expect from her. After Fukushima she immediately started to work on the complete shutdown.

Of course there might a lot of political calculation and the general mood shifted, but in Interviews she said that there was one thing that really got her. Fukushima was in Japan, and after Tschernobyl she always thought that this was an expected problem in a country like the Soviet Union, but in general nuclear should be safe. But after Fukushima, after the obviously bad planning and the mistakes that were done again and again, how can we expect that any country can manage the safety processes better, when Japan can’t do it. It’s not so much a technological question it’s a human and process question.

If nuclear is really needed, I would rather see it be the last resort option only in cases where renewables are not sufficient... but this conclusion about whether renewables are sufficient or not should be reached only after best efforts at renewables have been made, which is certainly not the case today.

Point is, the problem is financial, not technical. Nuclear, any nuclear design, is just expensive. As opposed to the bunches of a thousand windmills that T Boone Pickens wanted to slap up on whim in place after place. Those windmills start generating revenue a month later. It's just hard to compete with that. Which would you put your money into if you were the greedy energy investor?

Why would you think that? The problem with nuclear is that we are playing with significant tail risks, which are the hardest to engineer around. Catastrophic failures can have tremendous consequences, and in a sufficiently complex design there will be possibilities of catastrophic failures. While there are dead-simple reactor designs (like radiothermal), the vast majority of approaches work by layering complexity.

After Fukushima I became much more lukewarm on the subject of nuclear power, not so much because it was a huge Chernobyl-like disaster, but because I had repeatedly been told that a modern (post-Chernobyl) reactor was simply incapable of these failures modes. I had even, ignorantly, parroted back almost those exact words when discussing nuclear with people.

To me it's even more mind boggling that the club of rome 72 report was a Million-scale best seller printed book and nothing happened regarding energy and resource waste. And that's far less sensitive than nuclear physics.

Renewable means an energy source that literally renews itself. To avoid breaking the second law of thermos that implies there is an energy source (Sun) that recharges the renewable energy source with energy that would otherwise be wasted, therefore, you cannot net consume the resource.

In the case of wind and sunlight there is no net consumption of the resource because they'd otherwise be wasted (assuming you put solar over a parking lot and not over fertile land).

Nuclear cannot be renewable because fissile elements don't renew themselves (well, not without a supernova). We can extend the usefulness of the fuel with advanced reactors, but eventually all nuclear fuels, be they fast, thermal, fission or fusion end up with the most stable isotope of Fe - the most stable isotope.

In fact, fossil fuels are infinitely more renewable than nuclear fuels since eventually the biosphere dies, decays and some of material gets geologically captured to become fossil fuels (in geological timeframes).

There are (at least) two energy sources that are definitely not renewable: - Nuclear - Tidal (when we extract energy from a tide, the moon looses potential energy)

Renewable is a soft definition, however all things considered “renewable” are based off of solar, geothermal, or tidal power. Fission fuels are only generated as endothermic nuclear reactions in violent cosmic events, of which there are none on our schedule. How would we go about finding more fission material once we’ve burned it all up into stable isotopes? “Renewable” is best defined as “useable power that is isn’t non-renewable”. “Non-renewable” is easier to define, since it involves a very clear, short term, one way reaction. Also on fossil fuels: they stopped being generated millions of years ago, so, no, they are not renewable currently.