During the time when Sweden built the current nuclear reactors, some where built in just a few years. Sweden had experienced people back then that knew how to build them. We don’t have that anymore. Pretty much no one has.
We also had less examples of issues we need to be prepared for.
One thing people always get wrong is that they assume Fukushima wasn’t build to withstand tsunamis and how stupid that supposedly was. But it was built to withstand tsunamis. Up to 9 meters of height, which was 50% more than the largest one they had on record. And it’s not like they had other projects to look for to figure out that a 50% margin of safety was too little for this. Turns out, it was. So now, you want to build at least 100% margin of error in tsunami areas, something you couldn’t have known before.
And that’s just one example from one rather specific type of engineering during a construction process that isn’t even specific to nuclear power. And as accidents happen (see for example Admiral Cloudberg’s excellent air crash investigation series!) we figure out more and more things we need to engineer against to prevent this in the future. As a result, what we build nowadays is orders of magnitude safer than what we did in the past. But it also means that building it has become a huge obstacle, if for no other reason than the sheer number of things you need to be aware of, abide by and track during construction and planning.
Fukushima was not a failure of engineering or proper safety measures with construction. It failed because they were old plants that hadn’t been maintained properly and were in disrepair.
So no, the margin of safety was not too little. The “lesson” learned from the Fukushima Daichi reactor flooding was about proper maintenance and funding.
That’s the fundamental problem with nuclear energy. Where there are corners, they will be cut.
Turns out, it was.
It’s actually a bit worse than that.
The diesel generators flooded and that’s why the plant failed. The generators were asininely low; one was even in the basement. And yet it was built to code - the code simply had an oversight, as they often do. They could have built for 100 meter waves but if the design didn’t require sufficiently elevated generators, this was still going to happen.
The generator failure was known pretty immediately iirc but here is a source from USC (2015).
I knew a guy who worked at a hydro plant in a relatively remote area who gave up his car and walked a narrow, winding, mountainous road to work every day after the accident. He did so for years and may still do so. One man making what protest he can against our reckless growth. The accident rejuvenated the anti-nuclear sentiment all around. But the right-wing government has been working for years to counter them and is now planning new reactors. I don’t consider myself anti-nuclear but I think they are the wrong tool for the job. I’ve been ranting for years and now we are out of time. Plus regulation upheld by complex governments will suffer when society goes through a major simplification event (due to climate change). I already find building them in the Ring of Fire to be questionable, even with strong regulations.
