If those people that setup the tsunami stones are still alive during the incident they will have a kahuna of "I told you" moment.
>Before beginning construction, Tohoku Electric conducted surveys and simulations aimed at predicting tsunami levels. The initial predictions showed that tsunamis in the region historically had an average height of about 3 meters. Based on that, the company constructed its plant at 14.7 meters above sea level, almost five times that height.
>Tepco, on the other hand, to make it easier to transport equipment and to save construction costs, in 1967 removed 25 meters from the 35-meter natural seawall of the Daiichi plant site and built the reactor buildings at a much lower elevation of 10 meters.
https://thebulletin.org/2014/03/onagawa-the-japanese-nuclear...
Fukushima 1F was a failure of governmental regulation.
It's really important to understand that, because otherwise you inescapably frame the argument wrongly. Capitalism isn't the problem, regulatory weakness is the problem. No capitalist society can survive lack of effective regulation.
(Fukushima was bad, and an example of regulatory failure, but Japan's overall effective regulatory influence over its corporations — and similarly, its mafia — is the secret sauce that has made it an economic overperformer. China can also do that — because it is a brutal dictatorship. America can't do that — and things aren't looking good. UK retains the power to do it, but it's Keystone Kops. EU can't do it, either, for reasons I can't understand at distance.
But creating safe nuclear power plants is fundamentally the same problem as creating safe elevators. In a capitalist society, it's 100% about regulatory power and competence, and nothing else.
So if anything this weakens the Fukushima argument: in a country with excellent regulatory tradition and little evidence of regulatory capture, this is less likely to be about bad or lacking government regulations.
If A, then B does not imply "B, therefore A". This is called "affirming the consequent".
Similar to mitigating climate change effects 30 years ago. Now it's way too late.
Given the latter happens constantly, and the former is once in generations upon generations, I think it's safe to assume the problem is human and the tsunami was within historical ranges.
Especially since other reactors were hit by the same tsunami and were fine.
The issue is the height of the seawalls that was not sufficient (and perhaps historical warnings, if any, were ignored):
"The subsequent destructive tsunami with waves of up to 14 metres (46 ft) that over-topped the station, which had seawalls" [1]
Edit: Regarding historical warnings:
"The 2011 Tōhoku earthquake occurred in exactly the same area as the 869 earthquake, fulfilling the earlier prediction and causing major flooding in the Sendai area." [2]
[1] https://en.wikipedia.org/wiki/Fukushima_Daiichi_Nuclear_Powe...
Various construction changes could have prevented this from happening:
- the whole power plan being built higher up or further inland
-> this would likely be quite a bit more expensive due to land availability & cooling water management when not on sea level & next to the sea
- the emergency generators being built higher up or protected from a tsunami by other means (watertight bunker ?)
-> of course this requires the plan cooling systems & the necessary wiring itself working after surviving a massive earthquake & being flooded
An inland power plant - while quite wasteful in an island country - would be protected from tsunamis & certainly doable. On the other hand, I do wonder how would high concrete cooling towers handle strong earthquakes ? A lot of small cooling towers might have ti be used, like in Palo Verde nuclear generating station in Arizona.
Otherwise a bizzare case could still happen, with a meltdown possibly happening due to your cooling towers falling over & their cooling capacity being lost.
For light water reactors this basically just amounts to a large pool up a nearby hill or in a water tower.
Even when you correctly shut down the chain reaction in the reactor (which correctly happened in the affected Fukushima powerplant) a significant amount of heat will still be generated in the reactor core for days or even weeks - even if it was just 1% of the 3 GW thermal load, that is still 30 MW. It will be the most intense immediately after shutdown and will then trail off slowly.
The mechanism for this is inherent to the fission reactors - you split heavier elements into lighter ones, releasing energy. But some of the new lighter elements are unstable and eventually split to something else, before finally splitting into a stable element. These decay chains can take quite some time to reach stable state for a lot of the core & will still release radiation (and a lot of heat) for the time being.
(There are IIRC also some processes where neutrons get captured by elements in the core & those get transmutated to other, possibly unstable elements, that then decay. That could also result add up the the decay heat in the core.)
And if you are not able to remove the heat quickly enough - the fuel elements do not care, they will just continue to heat up until they melt. :P
I am a bit skeptical you could have a big enough reservoir on hand to handle this in a passive manner. What on the other hand I could image could work (and what some more modern designs include IIRC) is a passive system with natural circulation. Eq. you basically have a special dry cooling tower through which you pass water from the core, it heats up air which caries the heat up, sucking in more air (chimney effect). The colder water is more dense, so it sinks down, sucking in more warm water. Old hot water heating worked like this in houses, without pumps.
If you build it just right, it should be able to handle the decay heat load without any moving parts or electricity until the core is safe.
Some napkin math based upon heat capacity of water and assuming a 20 degree celsius input and 80 degree celsius output and 30MW heat results in about 120 liters per second of water flow needed. That is about 10 million liters of water per day, or about 4 olympic sized swimming pools. I don’t know how long you need to keep cooling for, but 10 million liters of water per day seems not insane and within the realm of possibility.
If you allow the water to turn into superheated steam you can extract much larger amounts of heat off the reactor as well.
Would work for volcanoes and earthquakes as well.
This probably works for a variety of things and in many places.
Well it depends. Very important shrines are dismantled and rebuilt every 20 years, eg https://japanwoodcraftassociation.com/2020/02/13/traditions-...
There are lots of old houses in use and for sale in Japan, but many people prefer building a new house to renovating or maintaining an old one - partly for practical reasons, partly because newer structures are more likely to be earthquake-resilient, partly due to haunting.
Century-old stone "tsunami stones" dot Japan's coastline (2015) - https://news.ycombinator.com/item?id=39892533 - April 2024 (142 comments)
Tsunami Warnings, Written in Stone (2011) - https://news.ycombinator.com/item?id=10122825 - Aug 2015 (10 comments)
Arguably books could be considered warning waystones, but that's a stretch in this context.
Physical monuments though, we have loads, lots of war memorials are/were intended as warning about the cost of war.
Auschwitz-Birkenau being left as as it is could be considered another.
If you want to get really close to similar intentions there are the long term nuclear waste warnings:
https://en.wikipedia.org/wiki/Long-term_nuclear_waste_warnin...
A bit more esoteric (and less warningy) and you get the signals we send in to space intentionally as a time-capsule/marker for potential alien contact.
Without clear warnings and boundaries humanity is just waiting for a catastrophe.
A tiny sign and words don’t count.
https://www.ans.org/news/article-416/the-art-of-the-10000yea...
"The 2011 Tōhoku earthquake occurred in exactly the same area as the 869 earthquake, fulfilling the earlier prediction and causing major flooding in the Sendai area. [1]
Modern society is not good at this sort of very long term consideration and planning.
https://archive.is/20161221102801/http://www.nytimes.com/201...