
The Fukushima accident was preventable - Oatseller
http://rsta.royalsocietypublishing.org/content/373/2053/20140379
======
bsder
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
dissociate the hydrogen and oxygen) rather than letting the core melt into the
bottom of the containment area _which was designed to deactivate and contain
the core_ , were also rampant.

This was just like Three Mile Island. If people had _sat on their hands, done
nothing, and let the engineered last-chance safety systems do their job_ ,
things would have turned out better.

Reactors should not be for-profit. Rickover showed us all how to do it right,
but we lack the stomach.

Here is his quote about real reactors: "On the other hand, a practical reactor
plant can be distinguished by the following characteristics: (1) It is being
built now. (2) It is behind schedule. (3) It is requiring an immense amount of
development on apparently trivial items. Corrosion, in particular, is a
problem. (4) It is very expensive. (5) It takes a long time to build because
of the engineering development problems. (6) It is large. (7) It is heavy. (8)
It is complicated."

~~~
dredmorbius
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), recent South Carolina
flooding and dam bursts, the Union Carbide Bhopal, India, disaster.

 _You cannot engineer out human nature._ This isn't a root cause for which
there are technical solutions.

I _hugely_ recommend Charles Perrow's _Normal Accidents_ and _The Next
Catastrophe_. As well as other writings.

Note that Rickover also wished we'd never gone to the nuclear option. He
defended his choice for lack of options, but would have preferred to see all
plants mothballed.

"Paper Reactors", which you quote in part, is _excellent_.

~~~
ars
> 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.

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

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

------
nickff
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 people
suffer from hindsight bias, and believe that this specific case should have
been foreseen. It is not clear what the cost of building everything to sustain
all similar low-probability events would be, and whether doing so would be
statistical murder.

~~~
PaulHoule
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.

~~~
ansible
_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 know how much those sorts of designs were developed at the time
Fukushima was commissioned though.

~~~
guscost
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...](http://web.mit.edu/nse/pdf/news/2011/Fukushima_Lessons_Learned_MIT-
NSP-025.pdf)

------
Johnny555
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".

~~~
WalterBright
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.

~~~
lucozade
Although it's been a very long time since I did engineering that could
actually kill people, this idea that you focus on what can go wrong and how
you mitigate it has stuck with me and has proved useful in lots of things.

Having said that, the next questions are usually: what is the likelihood of it
going wrong and what is the cost of mitigation? I don't envy the people making
those decisions on something like a nuclear reactor, with or without
hindsight.

~~~
WalterBright
At some point, you do assign a probability of systemic failure threshold, as
nothing is perfect.

The idea behind orthogonal backups, however, is that since they are
independent, very high reliability can be achieved with low reliable
components. For example, if you've got a main with 90% reliability, and a
backup with 90% reliability, the combined reliability is 99%. This can be a
lot easier and less expensive to achieve than making one component 99%.

The backup generators could have a cheap extra seawall built around them, or
could have simply raised them up on a 10 foot platform, or built them with
snorkels like a jeep designed to cross streams.

Building a heftier main seawall would have been an order of magnitude or two
more expensive.

------
Oatseller
It's a long read, here's a link to an article that summarizes some of the
study's findings.

[http://news.usc.edu/86362/fukushima-disaster-was-
preventable...](http://news.usc.edu/86362/fukushima-disaster-was-preventable-
new-study-finds/)

------
FussyZeus
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 they fell. Does that mean
they were engineered poorly too? 9/11 would've been prevented if we built
additional structure around the WTC each year to accommodate newer, larger,
heavier aircraft, but at what point do you rule safety cost as too high to be
justified?

On the same note, Fukushima survived a storm massively larger than it was ever
meant to. It still failed, but it did so in a way that prevented any direct
deaths. As nuclear "disasters" go, I honestly don't even think Fukushima
should be among them. Considering what COULD have happened, very little
actually happened.

How about we just agree to say we got lucky this time and do better in the
future?

~~~
mikeyouse
> 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 qualifies as a 'disaster'.

~~~
thaumasiotes
Eh. A traditional disaster kills people.

~~~
dalke
Eh?

I don't think "a traditional disaster" means what you think it means.

The Cerro Grande Fire destroyed about 420 homes and caused ~$1 billion in
damages but no one died. The Bel Air Fire destroyed 484 homes but again left
no fatalities. Tropical Storm Fay hit Texas and nine counties in Texas were
declared disaster areas, but again, no fatalities.

~~~
FussyZeus
But that's just stuff, the majority of which was probably insured and even if
it wasn't, all of it can (theoretically) be replaced. People can't.

~~~
dalke
I don't understand your response.

When was there ever a tradition where something had to have deaths in order
for it to be called a "disaster"? I gave three counter-examples of events
which were labeled disasters but which had no fatalities.

While what you said is (theoretically) true, all evidence is that it's
appropriate to use the term "disaster" for something which 'displaces tens of
thousands of people and costs several hundred billion dollars', and there's no
need to distinguish between 'traditional' and 'modern' definitions.

How does your comment fit into that context?

------
jonknee
In hindsight all accidents are preventable.

~~~
kevan
> 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 have made with the knowledge we had at the time.

~~~
PaulHoule
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.

------
craigching

      > causing the third most severe accident in an NPP ever.
    

I thought this was the second most severe nuclear power plant accident.
Obviously Chernobyl is the first, so what is the second according to this
article?

~~~
keypusher
Hmm. According to the International Nuclear Event Scale, there have only been
2 events at the most severe level (7): Chernobyl and Fukushima. There was 1
event at a rating of 6, which was a Soviet explosion in 1957. There was also
the Three Mile Island accident, which cost a lot of money to clean up (~$1
billion) but I don't think the severity was anywhere near Fukushima.

[https://en.wikipedia.org/wiki/International_Nuclear_Event_Sc...](https://en.wikipedia.org/wiki/International_Nuclear_Event_Scale#Details)

------
Animats
With that Mk 1 reactor design, lose cooling water for 4-6 hours and you get a
meltdown. The containment vessel is too small for the pressures in a worst-
case accident. It's just not a good design.

Peach Bottom station in Pennsylvania has the same Mk 1 design, and that's been
a worry for years. They now have extra backup power systems of different types
and multiple cooling water sources for that reason.

------
lurkinggrue
Aren't all accidents preventable?

------
NumberCruncher
>> The 11 March 2011 tsunami was probably the fourth largest in the past 100
years and killed over 15 000 people.

For me it still sounds to be a moronic idea to buid a nuclear power plant in
Fukushima. Or even to live there.

------
jrjr
Could have all been avoided. Japan's power consists of Fiefdoms and no
cooperation from adjacent working power sources at that time.

They could have run an "extension cord" and saved themselves from the entire
mess.

------
jessaustin
Of course they _have_ to say that. If they admitted how dangerous nuclear
power is, the bribes required to force the taxpayer to build new plants would
be simply _enormous_.

~~~
Avshalom
Literally no one died of radiation due to Fukushima.

~~~
Karunamon
As much as the parent comment is content-free, direct deaths aren't the only
thing to consider. There's also cancer and other diseases that can be caused
because of the increased radiation in the area, including that which got into
the food chain.

~~~
Avshalom
Yeah... the number of those deaths is estimated at somewhere between 0 and
100. Which is to say such a tiny number that it won't be empirically
distinguishable from normal fluctuations.

~~~
Karunamon
I said _diseases_ , not deaths. Cancer isn't always fatal, but they impact the
quality of life for the sufferers as well as putting an economic burden on the
healthcare system.

~~~
pdkl95
Ok. That's still only a handful of people in the worst cases.

Now what is the cost to the healthcare system of the coal power generation
that replaced the nuclear power stations that were shutdown after the tsunami?

------
worik
Really this is silly. People who advocate nuclear power do not understand the
difference between "risk" and "uncertainty".

"Risk" is where the probabilities of occurrence can be estimated and the
consequences predicted.

"Uncertainty" is the set of other things going wrong.

Nuclear risk can be managed: We can contain a nuclear pile, we can design
piping to withstand wear and sopply redundancy.

But with a nuclear power station if some thing unforeseen happens to the
containment vessel the consequences are ruin and effectively unbounded
catastrophe.

A coal burning stations are dirty polluting monstrosities (at their best) but
it is all risk.

Not that I am advocating coal, I am not! But nuclear is no replacement. We are
much better to do without energy than build nuclear power plants.

But the main incentive for nuclear power is making materials for bombs, IMO

