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Comment by btmorex | Hacker News Reader

This is a bad article.

1.) He argues that the three mile island accident means that the containment vessel will hold now. Even if they were the exact same reactor design, that doesn't logically follow, but they aren't the same design which gives even less credence to this argument.

2.) He says that once the reactor is flooded with water they won't have to do any more pressure releases. Again, I don't see how that follows. As long as there is enough residual heat to boil water, there's certainly a possibility that they will have to do more pressure releases.

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1.) Reactors aren't magic. They have very well defined properties. It's pretty easy to calculate if a containment vessel will hold. This type of engineering happens every day in every building you go in and every car you ride.

2.) The containment structure is quite large, and the residual heat is relatively low. There is a lot of water there, presumably too much for the residual heat to boil. (The water normally flows only in the much smaller reactor vessel.)

I'm not trying to convince anyone that the containment vessel will fail or that they will have to do more steam releases. I'm simply saying that the arguments presented in the article are illogical.

This isn't logic, this is science. Have you done experiments with large amounts of radioactive material that verify your hypothesis?

That criticism could be directed just as well at the original article, which is attempting to logically deduce why failure is unlikely (using questionable logic and analogies). It'd be much more convincing if the article instead presented something more like evidence, which likely also exists (since of course these designs are extensively tested).

Unsurprisingly, the article isn't written by a scientist; William Tucker is a pundit and journalist who writes about energy from a popular and political perspective. In his multiple books and hundreds of articles, he has done no experiments to verify any of his hypotheses.

" ... he has done no experiments to verify any of his hypotheses."

Personal experience or experimentation are not the only means of acquiring knowledge. In fact, most of our knowledge is gained by other methods (e.g. trusted sources).

Is he getting published in the Wall St Journal?

Look, I agree with the general viewpoint that we should build more nuclear power. But his points about the article are valid, and I don't see why he should be held to a higher standard than the PR flack getting free op-ed space.

Three reactors are affected, and two plants, Fukushima and Onagawa. I would say that an earth quake and tsunami is outside the well defined.

So earthquakes and tsunamis can alter physics making the impossible possible? If it's impossible for the rods to get hot enough to melt steel, then how does an earthquake followed by a tsunami change that? Somehow I think that you're latching on to the wrong part of the argument there.

http://www.reuters.com/article/2011/03/14/us-japan-quake-idU...

"Nuclear fuel rods at one of the reactors may have become became fully exposed raising the risk they could melt down and cause a radioactive leak, Japanese news agency Jiji said."

The properties of the fuel rods didn't change due to the tsunami+earthquake. If the article it wrong, it's wrong. But it's not wrong because things are 'different this time.'

> I would say that an earth quake and tsunami is outside the well defined.

But at the same time they are not completely independent events. Quite the opposite. It is likely that an earthquake will be followed by a tsunami.

If they engineered it so that 2 events: quake and flood are independent, then they made a mistake. Possibly there is nothing they could do but I doubt that.

This is somewhat similar to the birds and airplane engines. It is assumed that once in a while a bird will hit an engine and possibly take it out. No big deal, there are 1,2 or 3 more engines. But the problem is that birds fly in flocks. So chances are that the plane will fly into a flock of birds and all engines will go out. Which is what happened a year or two ago. Now there is probably not much they could do but hopefully at least they didn't assume that invidual engine failure due to bird hits would be completely independent failure events.

Completely agree with this. On the other hand, all their safety mechanisms so far have failed. Electric, diesel based and the automatic steam based. Which is why they now manually try to pump in sea water (according to what I have understood from the news). I'm not against science, but still, it seems that the situation is surrounded by a fair amount of uncertainty. So, to my way of thinking the most wise is to treat it as an uncertainty, until we know more from official sources.

>On the other hand, all their safety mechanisms so far have failed. Electric, diesel based and the automatic steam based.

Wrong and wrong. Some backup cooling mechanisms have failed, not all safety mechanisms.

The electric backup worked as designed. The diesel backup did not, as I understand it, because it was affected by the tsunami (which is inexcusable in my opinion). And the backup diesel generators brought in from off-site, from what I've read, could not be attached due to incompatible connectors (which if true, is also inexcusable).

>The electric backup worked as designed.

No, that is the reason they where suppose to fall back on diesel based pumps. The electrical outage after the quake made the electric pumps fail. The diesel based pumps also failed as we agree upon. After that there was a mechanism simply based on preasure which supposed to push out hot steam, cool it off and feed it back as water. However this mechanism led a decreased level of water (from what I have heard). Which is why they now resort to pumping it in manually. I think it's safe to say that two major explosions at the plant (even though it wasn't the reactor it self apparently) is a sign of failed safety mechanisms.

There are batteries, they ran the pumps for almost 8 hours. That was one of the backups.

Yeah you are right, but that wasn't sufficient enough to solve this on the other hand.

Well the batteries are exactly the "electric backup" that was mentioned, although you're also right in that it was never designed to solve the entire casualty, only to last long enough to get other sources of power online.

Actually, two plants in Fukushima. Onagawa is in Miyagi and is not affected, though they did detect heightened radiation readings probably from Fukushima.

I guess your right.

http://www.reuters.com/article/2011/03/11/quake-japan-nuclea...

And then later.

http://www.reuters.com/article/2011/03/13/japan-quake-onagaw...

Which at least points to the uncertainty and conflicting messages. But it's good to know that the situation has stabilized and it now is clear that it does not face the same difficulties.

On #1, it's specifically the TMI comparison in the article that isn't very convincing, because many of the postmortems (though there is some disagreement) conclude that it was somewhat luck that the corium didn't melt through the containment at TMI, due to the specific pattern of melting and cooling. So the fact that it held doesn't tell you what would happen in another incident with much confidence (even if the two designs were the same, which they aren't). There may be other reasons to conclude that breaching containment is unlikely, but the particular argument the article presents isn't a great one.

> He says that once the reactor is flooded with water they won't have to do any more pressure releases. Again, I don't see how that follows.

He's just not stating the (true) premise that the seawater will be able to absorb the heat; he's implying it and relying on it. That doesn't make the article illogical, it makes it mildly enthymematic.

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