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Why Fukushima Was Preventable

carnegieendowment.org

1–10 of 28 posts

Re: Why Fukushima Was Preventable

#2
Long article, but the best one I've run across explaining the inputs used to choose design tolerances, the advances in those methods over the years, and where the Fukushima design and later maintenance was and wasn't in accordance with best practices.

The overall conclusion is that it was known by the early 2000s that the plant's worst-case tsunami estimate, used as its design basis, was no longer sufficient, given improved understanding of tsunamis. At that time, a significant upgrade should have been initiated, since the original design-basis tsunami of 3.1 meters was no longer believed to be a good estimate of the worst case. But those reports basically got buried and nothing was acted on.

Side note: I was wary of submitting, because we've just had a big round of Fukushima and nuclear discussion/debate, and rehashing the same debate in another thread doesn't seem productive. But imo this article is quite informative and worth a read.

Re: Why Fukushima Was Preventable

#3
I don't think it's really relevant. The point is not that there is a way to have safe nuclear energy, the point is that the worst case scenario is catastrophic, and that I don't trust any company or government to do what's necessary, especially if they're strapped for cash.

Re: Why Fukushima Was Preventable

#4
post #3

I don't think it's really relevant. The point is not that there is a way to have safe nuclear energy, the point is that the worst case scenario is catastrophic, and that I don't trust any company or government to do what's necessary, especially if they're strapped for cash.

That's not entirely true. There are a lot of new designs (i.e.: not BWR) that passively cool and shutdown without the input of any external energy.

Also, molten salt reactors and fusion reactors won't be able to have catastrophic failure modes either.

Re: Why Fukushima Was Preventable

#5
post #3

I don't think it's really relevant. The point is not that there is a way to have safe nuclear energy, the point is that the worst case scenario is catastrophic, and that I don't trust any company or government to do what's necessary, especially if they're strapped for cash.

That's not entirely true. There are a lot of new designs (i.e.: not BWR) that passively cool and shutdown without the input of any external energy. Also, molten salt reactors and fusion reactors won't be able to have catastrophic failure modes either.

You can dramatically slow reactors down, but you can't actually 'shut down' because simply decay produces significant amounts of heat. So the real problem at Fukushima was the need to be able to passively cool a reactor indefinitely in that 'slow' state without human interaction and that's where they failed. Sure, if they had power and none of the connectors had failed it would have also been ok, but without long term passive safety nuclear power is not safe.

Re: Why Fukushima Was Preventable

#8
post #3

I don't think it's really relevant. The point is not that there is a way to have safe nuclear energy, the point is that the worst case scenario is catastrophic, and that I don't trust any company or government to do what's necessary, especially if they're strapped for cash.

The worst case scenario of a natural disaster is also catastrophic, and they don't even have significant benefits. Nuclear power does, as it doesn't produce greenhouse gasses, and reduces dependence on fossil fuels. And like the other comment said, new types of reactors are completely different and we shouldn't have an irrational fear of nuclear power in general because of accidents like this.

Re: Why Fukushima Was Preventable

#9
post #5

Earlier quoted context omitted.

That's not entirely true. There are a lot of new designs (i.e.: not BWR) that passively cool and shutdown without the input of any external energy. Also, molten salt reactors and fusion reactors won't be able to have catastrophic failure modes either.

You can dramatically slow reactors down, but you can't actually 'shut down' because simply decay produces significant amounts of heat. So the real problem at Fukushima was the need to be able to passively cool a reactor indefinitely in that 'slow' state without human interaction and that's where they failed. Sure, if they had power and none of the connectors had failed it would have also been ok, but without long ter…

Yes, I understand that you can't just turn them "off." It's easiest just to say that it's shut off if it's unable to do anything really.

I think you missed everything in my previous post. All new designs passively cool. You can have safe (comparative to coal and gas) nuclear power.

Re: Why Fukushima Was Preventable

#10
post #6

Isn't everything preventable with the benefit of hindsight?

I think the key is that they already had the hindsight years before the accident occurred. They knew, from incidents at other plants and from tsunamis in other areas that the assumtions made when the plant was designed were wrong and the plant was vulnerable. They chose not to act on that knowledge.
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