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The Fukushima accident was preventable

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Re: The Fukushima accident was preventable

#61

Post by FussyZeus »

mikeyouse wrote: post #51
FussyZeus wrote: post #44

Here's something about the real world: Things break. Shit happens. We can sit on a chair now and look back and point out all the things that could've been done better, and I honestly don't see the value in it. When the World Trade Center was built, it was designed to withstand the impact of a common airplane at the time and remain structurally sound. The engineers didn't envision a 757 being flown into them, and so t…

> As nuclear "disasters" go, I honestly don't even think Fukushima should be among them. Considering what COULD have happened, very little actually happened. There are hundreds of square miles still in the exclusion zone and some 80,000 people haven't been able to return to their homes.. I'd say a nuclear meltdown that displaces tens of thousands of people and costs several hundred billion dollars to clean up qualifi…

With all respect due, I think the former residents of Pripyat would disagree with you.

Re: The Fukushima accident was preventable

#62

Post by dredmorbius »

maxerickson wrote: post #33
dredmorbius wrote: post #29

Earlier quoted context omitted.

British use of quotes is typically distinguished from American, in that where emphasis using language from the original document is intended, those words are typically quoted. You'll see this extensively in BBC headlines. They're not "scare quotes", to quote you. They're direct quotations, for emphasis .

Those quote marks are in the report to indicate sarcasm.

Useage elsewhere doesn't support your comment. E.g., in the introduction:

Interestingly, while the Onagawa NPP was also hit by a tsunami of approximately the same height as Dai-ichi, it survived the event ‘remarkably undamaged’.

Re: The Fukushima accident was preventable

#63

Post by dredmorbius »

ars wrote: post #56
dredmorbius wrote: post #28

Earlier quoted context omitted.

The point that it's organisational and management issues which so frequently seem to be behind major disasters -- four of the larger nuclear accidents (Fukushima, the earlier Japanese criticality incident at Tokaimura, Chernobyl, Three Mile Island), as well as numerous other large-scale industrial accidents, of which energy systems play a large role: the BP Gulf Oil spill, Exxon Valdez, Banqiao Dam (China, 1975), rec…

> You cannot engineer out human nature. This isn't a root cause for which there are technical solutions. Have you heard the saying: In the future they will be staffed by a man and a dog. The man to feed the dog, and the dog to bark at the man in case he tries to touch anything.

I have. Frequently when making comments similar to those above ;-)

(The dog is doing his job....)

Re: The Fukushima accident was preventable

#65

Post by dredmorbius »

Retric wrote: post #35
dredmorbius wrote: post #28

Earlier quoted context omitted.

The point that it's organisational and management issues which so frequently seem to be behind major disasters -- four of the larger nuclear accidents (Fukushima, the earlier Japanese criticality incident at Tokaimura, Chernobyl, Three Mile Island), as well as numerous other large-scale industrial accidents, of which energy systems play a large role: the BP Gulf Oil spill, Exxon Valdez, Banqiao Dam (China, 1975), rec…

You cannot engineer out human nature. You can do a lot to minimize the effects of human nature or even utilize it. You just need to build systems for humans not some abstract ideal. Case in point, the giant Menu inside a fast food restaurant has a lot of counter intuitive properties designed to alter people’s behavior. It's not pretty, but it works. Note, we are talking about the masses of humanity not just those you…

You can engineer to influence human nature. But often the task is, as you highlight, to take existing tendencies and influence them. Fast food, and consumer marketplaces generally, are highly engineered to prompt desired behaviors. Those generally aren't, though, very high reliability error-correcting behaviors.

Some other examples that come to mind:

1. Public spaces designed to be "riot proof". Generally this works by avoiding single large assembly points, putting entrances and exits such that there's no through transit of a space or building, and otherwise dispersing the energy of crowds.

2. Las Vegas. The manipulation is so grossly apparent to me that the entire place disgusts me. Windowless interiors, no clocks, bright lights and flashing displays, loud music. And, most iconically: moving walkways to take you into casinos, but having to depart under your own power.

3. Much of air safety practices. While it's not possible to design out pilot (or other human) error, you can become highly aware of what leads to accidents. The commercial air travel industry is a fascinating study in risk reduction, starting with the goal of incident studies, which is to ascertain cause, not assign blame.

Perrow goes into this in depth in his books.

Re: The Fukushima accident was preventable

#66

Post by api »

bsder wrote: post #22

Of course it was, as were things like the explosions afterward. However, management always gets in the way--either up front, because there is profit pressure, or on the backend, because there is profit and/or political pressure. This paper covers the up front failures. However, backend failures, like spraying water on the core ( NOT one of the established procedures because calm engineers knew that the reactor could…

(9) solar+wind+storage is orders of magnitude simpler, can be incrementally financed, and is nearly on parity in many markets.

The middle point -- ability to be incrementally financed -- cannot be overstated.

Re: The Fukushima accident was preventable

#67

Post by ori_b »

jakeogh wrote: post #46
bsder wrote: post #22

Of course it was, as were things like the explosions afterward. However, management always gets in the way--either up front, because there is profit pressure, or on the backend, because there is profit and/or political pressure. This paper covers the up front failures. However, backend failures, like spraying water on the core ( NOT one of the established procedures because calm engineers knew that the reactor could…

"sat on their hands, done nothing" That's how it should be, but in this case not doing anything was not an option. The passive (gravity fed) cooling system on the first reactor to melt had it's valve's almost closed when they lost power. Seems like a bad design to even have valves on it but I'm not a Nuclear Engineer. And people at Daini were able to prevent meltdowns by hand-laying miles of high current cable. Reaso…

> The passive (gravity fed) cooling system on the first reactor to melt had it's valve's almost closed when they lost power. Seems like a bad design to even have valves on it but I'm not a Nuclear Engineer.

It wasn't a great design. But that's what happens when you take reactors that were built before Chernobyl, were optimized for producing material suitable for nuclear bombs instead of safety, and then run them long past their designed lifespan.

More or less, these reactors should have been retired long ago, and replaced with more modern designs.

Re: The Fukushima accident was preventable

#68

Post by PaulHoule »

nickff wrote: post #21
PaulHoule wrote: post #15

Earlier quoted context omitted.

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…

I have read that many times, and it makes some sense. The issue with this line of reasoning is that the move would be a design change which is not required by the specification (as I have read and understood it), which would have been seen as unnecessary waste at the time. A study which I would find more important and useful than the one here would be a cost/benefit analysis of increasing all specifications relating…

When you consider that a nuclear plant costs billions of USD and that billions of USD of damage has been done, the $500,000 upgrade to the generators is a slam dunk. Also based on recent projections, the probability of a tsunami event of that severity was 80% for the next few decades, so it is a no brainer -- particularly when you consider that the nuclear industry worldwide has been set back 20 or 40 years at least by this incident.

The NRC has had modernization plans at U.S. reactors that have spent much more than this. For instance the hydrogen bubble formation in that kind of BWR was well known here and reactors in the U.S. have had features added (dependent on a power source) that would get rid of it.

Re: The Fukushima accident was preventable

#69

Post by abduhl »

seanflyon wrote: post #53
maxerickson wrote: post #20

Earlier quoted context omitted.

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 Chi…

> the tsunami it experienced was accepted by the best engineering data at the time to be impossible. I find that hard to believe. It was the 4th largest earthquake in the last century and doesn't make the Wikipedia list of "Megatsunamis". It was more a question of how long between such extreme events than if such an extreme event could occur.

Megatsunamis are caused by large volumetric displacements of water resulting from massive amounts of earth entering the water. The tsunami that caused the Fukushima disaster was not a megatsunami - it was caused by thrust faulting resulting in underwater displacement rather than the megatsunami mechanism discussed above.

The analogy here is splashing your hand into water (megatsunami) versus moving your hand underwater.

Re: The Fukushima accident was preventable

#70

Post by guscost »

ansible wrote: post #24
PaulHoule wrote: post #15

Earlier quoted context omitted.

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…

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. This is the one simple problem. There are now reactor designs that are passively fail-safe. So that even if all the pumps and everything stop, it will still not result in an explosion or otherwise serious release of radioactive material. I don't k…

BWR reactors like Fukushima are all passive-safe in at least one way, since water moderates the neurons coming off the critical materials, slowing them enough to continue the reaction. If the water boils away, sure the thing will almost certainly melt but there won't be a runaway prompt-critical event like Chernobyl, and if the concrete "bathtub" around the core holds, there won't be much radioactive material released into the groundwater either.

From what I heard the concern at Fukushima was that the earthquake had compromised the integrity of the containment structure, so allowing the core to melt down was judged as too risky (I'm not sure if I agree with that decision, but of course my opinion in hindsight is not relevant). In fact the majority of radioactive material that was released in the incident might have leaked from the spent fuel storage, which was also damaged in the earthquake:

http://web.mit.edu/nse/pdf/news/2011/Fukushima_Lessons_Learn...

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