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The Fukushima accident was preventable

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Re: The Fukushima accident was preventable

#11

Post by joe_the_user »

Johnny555 wrote: post #7

Isn't every accident preventable in hindsight since you know exactly what the failure mode was? If they'd built the generators on a hillside that was washed away in a mudslide the article would read "Critical backup generators were built on unstable hillside despite warnings from scientists".

Indeed, and most accidents can shown to have been preventable "if international best practices and standards had been followed, if there had been international reviews, and had common sense prevailed in the interpretation of pre-existing geological and hydrodynamic findings." [the article]

But claims would seem to be little more than a thin gloss on the unbreakable unobtainium[1] of your hindsight.

[1]https://en.wikipedia.org/wiki/Unobtainium

Re: The Fukushima accident was preventable

#12

Post by WalterBright »

Johnny555 wrote: post #7

Isn't every accident preventable in hindsight since you know exactly what the failure mode was? If they'd built the generators on a hillside that was washed away in a mudslide the article would read "Critical backup generators were built on unstable hillside despite warnings from scientists".

The idea with building safe systems is not to imagine what could cause subsystem X to fail, but to figure out how to cope when subsystem X fails.

The most obvious design failure at Fukushima was not "how big a tsunami we should protect against" but not asking "how will we cope when the seawall fails".

If the critical backup generators had been in a bunker designed to protect them from a seawall breach, the disaster would not have happened.

Re: The Fukushima accident was preventable

#13

Post by maxerickson »

Shivetya wrote: post #10
maxerickson wrote: post #8

Earlier quoted context omitted.

Here's a key phrase from the abstract that suggests more than hindsight bias is involved in the report: The Fukushima accident was preventable, if international best practices and standards had been followed, if there had been international reviews, and had common sense prevailed in the interpretation of pre-existing geological and hydrodynamic findings. Another one: Three, the hazard analysis to calculate the maximu…

When it was built or after? This plant was built in the early eighties. The article doesn't state if it violated the ideals of then or more recent knowledge.

The comparison to Onagawa makes it clear enough that they are talking about when it was built. They wouldn't have had so much more experience in 1968 than when they did the early design work for Fukushima Dai-ichi.

Re: The Fukushima accident was preventable

#14

Post by samstave »

Shivetya wrote: post #10
maxerickson wrote: post #8

Earlier quoted context omitted.

Here's a key phrase from the abstract that suggests more than hindsight bias is involved in the report: The Fukushima accident was preventable, if international best practices and standards had been followed, if there had been international reviews, and had common sense prevailed in the interpretation of pre-existing geological and hydrodynamic findings. Another one: Three, the hazard analysis to calculate the maximu…

When it was built or after? This plant was built in the early eighties. The article doesn't state if it violated the ideals of then or more recent knowledge.

Fukushima was built in 1967... and was based on an even slightly older GE plant design.

Or were you talking about the other plant?

Re: The Fukushima accident was preventable

#15

Post by PaulHoule »

nickff wrote: post #4

As I understand it, the Fukushima plant was never designed or rated to sustain such a large earthquake or tsunami. If this understanding is correct, we should not have expected it to survive the damage, and the problems were not with the design, but perhaps with the specification (depending on whether you think this should have been foreseen). It seems to be a common thread with all tragedies and disasters that peopl…

If you read closely you see that the accident was so bad because of one simple problem.

If a nuclear reactor has a cooling failure, the fuel will eventually heat up and then melt down. To prevent this you have to keep water circulating around the reactor core. It doesn't take a huge amount of energy to do this, but it does take some. If the power goes out at the station and they can't get emergency power, the outcome is very bad.

If they had spent maybe $300k or so they could have moved the emergency generators a little bit higher up. With that investment there still would have been serious damage to the plant but only a very limited release of radioactivity because the fuel integrity and the coarse integrity of the plant would have been protected.

Re: The Fukushima accident was preventable

#16

Post by PaulHoule »

kevan wrote: post #6
jonknee wrote: post #3

In hindsight all accidents are preventable.

> The Fukushima accident was preventable, if international best practices and standards had been followed, if there had been international reviews, and had common sense prevailed in the interpretation of pre-existing geological and hydrodynamic findings. I think the main point is that the damage wasn't caused by a freak storm that no one could have predicted. It was caused by a series of mistakes that we shouldn't ha…

The report says that for less than $1M they could have raised the emergency generators up higher in which case they could have maintained reactor cooling and had reactor damage but no major harm. Also there was evidence of similar events in the inhabited past.

Re: The Fukushima accident was preventable

#18

Post by [deleted] »

PaulHoule wrote: post #15
nickff wrote: post #4

As I understand it, the Fukushima plant was never designed or rated to sustain such a large earthquake or tsunami. If this understanding is correct, we should not have expected it to survive the damage, and the problems were not with the design, but perhaps with the specification (depending on whether you think this should have been foreseen). It seems to be a common thread with all tragedies and disasters that peopl…

If you read closely you see that the accident was so bad because of one simple problem. If a nuclear reactor has a cooling failure, the fuel will eventually heat up and then melt down. To prevent this you have to keep water circulating around the reactor core. It doesn't take a huge amount of energy to do this, but it does take some. If the power goes out at the station and they can't get emergency power, the outcome…

[deleted]

Re: The Fukushima accident was preventable

#19

Post by ChuckMcM »

maxerickson wrote: post #8
nickff wrote: post #4

As I understand it, the Fukushima plant was never designed or rated to sustain such a large earthquake or tsunami. If this understanding is correct, we should not have expected it to survive the damage, and the problems were not with the design, but perhaps with the specification (depending on whether you think this should have been foreseen). It seems to be a common thread with all tragedies and disasters that peopl…

Here's a key phrase from the abstract that suggests more than hindsight bias is involved in the report: The Fukushima accident was preventable, if international best practices and standards had been followed, if there had been international reviews, and had common sense prevailed in the interpretation of pre-existing geological and hydrodynamic findings. Another one: Three, the hazard analysis to calculate the maximu…

I'm not sure if you agree that the findings are unsustainable or not. Two things that the IAEA had established were that

1) Fukishima survived the earthquake as designed, and was in the process of shutting down when the tsunami hit.

2) The tsunami disabled primary and backup power to the cooling systems which was the proximate cause of the failure.

Further, at the time of its commissioning, the tsunami it experienced was accepted by the best engineering data at the time to be impossible.

You can make the argument that over time as more data became available the regulatory agency should have required additional upgrades to cover the larger tsunami risk. There have been plenty of stories about regulatory capture between TEPCO and the regulators which prevented best practices from being followed.

A lot of retrofits had been installed over time and that no doubt contributed to its survival of the earthquake.

Re: The Fukushima accident was preventable

#20

Post by maxerickson »

ChuckMcM wrote: post #19
maxerickson wrote: post #8

Earlier quoted context omitted.

Here's a key phrase from the abstract that suggests more than hindsight bias is involved in the report: The Fukushima accident was preventable, if international best practices and standards had been followed, if there had been international reviews, and had common sense prevailed in the interpretation of pre-existing geological and hydrodynamic findings. Another one: Three, the hazard analysis to calculate the maximu…

I'm not sure if you agree that the findings are unsustainable or not. Two things that the IAEA had established were that 1) Fukishima survived the earthquake as designed, and was in the process of shutting down when the tsunami hit. 2) The tsunami disabled primary and backup power to the cooling systems which was the proximate cause of the failure. Further, at the time of its commissioning, the tsunami it experienced…

This report directly disagrees with Further, at the time of its commissioning, the tsunami it experienced was accepted by the best engineering data at the time to be impossible. Directly.

This part uses scare quotes to describe the 'quality' of the work:

Its initial application was based on the 3.122 m measurement local tsunami height (above Onahama Peil (O.P.) reference sea level), observed during the 1960 Great Chilean tsunami at or close to Fukushima [32]. The flooding estimate was provided to the nearest millimetre, underscoring a false sense of accuracy in the safety assessment that is impossible even today. With hindsight, it also underscores the ‘quality’ of the engineering work and of its review.

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