>Onagawa was… 60 kilometers closer than Fukushima Daiichi [to the epicenter] and the difference in seismic intensity at the two plants was negligible. Furthermore, the tsunami was bigger at Onagawa, reaching a height of 14.3 meters, compared with 13.1 meters at Fukushima Daiichi. The difference in outcomes at the two plants reveals the root cause of Fukushima Daiichi’s failures: the utility’s corporate “safety culture.”
>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.
This is why so many people are against nuclear. It may be theoretically possible to create safe nuclear plants, but capitalism is badly equipped to create them.
Maybe you mean democratic societies are badly equipped to regulate capitalist economies? There are zero successful capitalist economies that lack powerful governmental regulatory control.
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.
Partlially agree, but one needs to try really, really hard to intentionally overlook the whole "influence of corporate giants on government" issue before the government regulation argument carries any practical weight.
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.
I can't tell if this is a tongue in cheek joke or just blatant ignorance. The biggest in size and death nuclear powerplant disaster was Chernobyl under communism and it wasn't there first or last.
The reactors were also largely fine except for grid connections and the hurricane-resistant backup generator in the basement. It was told ad nauseum at the time that there could have been couples of those on the roofs and the reactor could have just survived.
What's more likely, worst tsunami ever, beyond previous safety stones? Or company shortcuts safety and falls over because they failed to account for predictable circumstances?
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.
Do you have a citation for this? The most Gemini could say is: "While research has not identified a specific tsunami stone located at the Fukushima Daiichi site that was directly violated, the spirit of these ancient warnings was undeniably ignored." (https://aistudio.google.com/app/prompts?state=%7B%22ids%22:%...)
I don't know if there are "Tsunami stones" in the area but the nuclear power plant is built at sea level [1] so would most probably be below them.
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]
IIRC the issue was the emergency diesel generators being flooded, preventing them from powering the emergency cooling pumps, resulting in the meltdowns from residual heat in the reactor cores and spent fuel pools.
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.
Another option is designing fail safe reactors. CANDU reactors designs are over 60 years old now and were built fail safe so that if outside power to the core is cut off the system would safe itself by dropping control rods which are held up by electromagnets into the core.
A reactor scram isn't necessarily enough -- you still have decay heat to worry about. In the case of Fukushima, the fission chain reaction was stopped but without cooling pumps the decay heat was still too much.
It seems like you should build a water reservoir at a higher elevation than the core and then apply a similar principle where valves regulate the water stream, but if the valves lose power they fail open. The reservoir can be built so that there is always enough water to cool the core.
For light water reactors this basically just amounts to a large pool up a nearby hill or in a water tower.
That is easier said than done - modern reactors are in the 1000 MW+ electrical power range, which means about 3x as much heat needs to be generated to get this much electricity - say 3000 MW.
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.
Yea, it seems like you could design a cooling loop that runs just off the latent heat. Im sure somebody in reactor design has sketched it out.
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.
there are reactor designs that work that way, but most civilian power plants are pressurized water reactors. it is important that the water stays pressurized or you get a chernobyl
Fukushima was based on a Westinghouse BWR (Boiling Water Reactor) design, so pressurization was not that much of an issue - if enough of sufficiently cold water was provided, there would be no meltdown.
If those people that setup the tsunami stones are still alive during the incident they will have a kahuna of "I told you" moment.