Hacker News new | comments | show | ask | jobs | submit login
Why I am not worried about Japan’s nuclear reactors (morgsatlarge.wordpress.com)
415 points by woodpanel on Mar 13, 2011 | hide | past | web | favorite | 182 comments

The article is mostly correct, but a few corrections from a nuclear engineer:

1. What he refers to as "moderator rods" are actually control rods. The term "moderator" refers to a material that is unlikely to absorb neutrons, but likely to scatter them. This helps lower the average neutron speed inside the reactor, which actually increases the fission rate. Since water serves this purpose just fine, most reactors do not have specific "moderator rods", although BWRs actually run pipes of liquid water through the fuel assemblies for additional moderation.

2. BWRs are not run all-rods-out, like he claims. BWRs are generally run with significant control rod insertion, so that the water stays liquid for a greater portion of the height of the core.

3. He doesn't quite explain that the source of the hydrogen is a replacement reaction where zirconium and water react to create zirconium oxide and hydrogen gas.

4. Xenon-135 is a fission product, not produced by neutron activation, and neutron activation of coolant is nothing to sneer at (the half-life of tritium is 12.3 years).

Also, correct me if I'm wrong, but Cs-137 has a half life of 30 years or something. It certainly does not disappear quickly. Most of the Chernobyl contamination in Sweden was from Cesium, and that made berries and reindeer (which eat lichens) unsafe to eat for many years, if not decades.

Yeah, 30 years.

There was a lot of background radiation from Cs-137 from all the old nuclear testing that's disappearing now.

ummm half life means factor 2 in activity reduction. to obtain a factor 1000 in activity reduction you would have to wait 10 times as long. 300 years?

for 4. Tritium is a beta emitter. Wherever it ends up when it decays, the radiation won't get very far.

Still not good when it ends up in your body.

True, although in fairness it's a fairly weak beta emitter. The 100,000 picocuries of Potassium-40 your body has emits betas that are about 120 times more energetic, or sometimes emits gamma rays instead.

Probably better to not get exposed to tritium all other things being equal but you would receive more damage from radioactivity IMO inhaling someone's cigarette smoke. I suppose this depends on exactly how much tritium is present in the steam that was vented.

The original engineer also left out the many other radionuclides that are created that don't break down instantly, but his points about filtering most contaminants out before they are vented, and their destination of the vast Pacific Ocean is right on target.

Range of Betas in air (I believe at 1 MeV) is 12 feet. These aren't alphas here, they'll make it into living tissue.

Tritium betas are about 0.005 MeV, not 1.000, and can penetrate only 6mm of air. The only real threat from tritium is ingestion where you don't have air or dead skin layer to block them, but even then they would have to be present in vast, vast quantities to receive appreciable dose from them.

What is nicer is that your body naturally replaces most of its water every few days, so you arn't stuck like you would be with say sr-90 trying very hard to embed itself in your bones :(

Would you provide more detail on #4? I'm curious but not quite getting what the consequences of this are.

It means there are isotopes, including tritium, whose half-lives are long enough that they pose a risk to the health of anyone who happens to inhale or ingest them. The OP's dismissal of such risks is a bit facile.

But tritium pretty much can't be made in light water reactors, so there isn't going to be any in the released steam.

True, but the reactors aren't full of light water anymore, they are pumping sea water into them.

Where does the tritium come from? As I recall tritium is one proton and two neutrons. So, you are saying that one hydrogen, that is, one proton, from the water captures a neutron and becomes deuturium and then later the deuturium captures another neutron and becomes tritium? Is that correct? Net, to those two reactions have a signficant reaction rate in the context?

There's a significant amount of conversion from hydrogen to deuterium. The likelihood of neutron absorption by deuterium is much smaller (by a about a factor of ten) than the likelihood of neutron absorption by plain hydrogen, but it still happens since there's a lot of neutron flux.

Canadian reactors (the CANDU design) use heavy water as moderator because it doesn't absorb neutrons as readily, and the improvements in neutron economy allow them to avoid enriching their fuel.

Radiation from tritium is definitely something that we worry about as far as worker safety near piping containing irradiated water, but it's not something that concerns us too much as far as being vented into the environment (we try to minimize that, but there's only so much you can do, especially with a BWR).

My high school class in Switzerland was chosen for the yearly measurement of radioactivity in the population. The graphs they showed us as intro were interesting. Basically they start in the mid-60's and were going down. The level then flatlined at zero for many years. Then Chernobyl came and was a small blip something like 5x less than the 60's level.

Turns out a complete meltdown of a civilian reactor a few thousand miles away matters less than open air explosion of multi-megaton bombs on the other side of the world, which was the cause for the 60's levels.

Not that I wish nuclear meltdown on anyone, but the above seems to me to suggest that on a worldwide scale it wouldn't have much of an impact.

Thank you for reminding us of how much of a non-event the Chernobyl accident was for you in Switzerland, a few thousand miles away. While you're at it, don't forget tell those wimps in Belarus to shut up and stop whining about this non-event.

You're right. For them it was an absolute tragedy. I wasn't implying otherwise.

But the premise of the OP was some Australians that were freaking out because of the events in Japan. It's a similar situation.

From the comments looks like the OP lives in Japan, hence his family's concern.

Very true! I hadn't read the comments.

In theory we should be more worried about the ash radiation from our coal plants (which releases a lot more, in an unregulated manner, and makes me wonder sometimes if it's a trigger for the increase in cancer in industrialized nations).


it is estimated that during 1982, US coal burning released 155 times as much uncontrolled radioactivity into the atmosphere as the Three Mile Island incident

That’s because hardly any radioactivity was released into the atmosphere during the Three Mile Island incident. It was mostly harmless.

I think you are missing some documentation


I don't know what the population density is, from your graph, it sure looks like Three Mile Island prevented a bunch of cancer. (Assuming of course you want to infer causality from one picture.) Look at all that dark green - those are areas with 50% less cancer than would be expected.

The wikipedia article suggests the science is very mixed, and there is no conclusive evidence one way or the other.


So whatever the effects of TMI were, they are almost certainly small.

The red areas almost look like where the wind would carry a radioactive plume. Why do you believe it would go towards the green area and disperse in a uniformed way?

There have been several studies of health effects in the aftermath of the Three Mile Island incident, some (like this one) found effects, some didn’t.

But that’s not even that important to the point I was trying to make. The amount of radioactivity released into the atmosphere was very low, in a real disaster (like in Chernobyl) much, much more radioactivity is released – more than any one coal power plant could ever release.

Point is that you are comparing effects of relatively unlikely accident with effects of normal operation.

It looks to me as though one or two Chernobyl sized disasters per century can very much upset that balance.

Deaths obviously still matter but I don't think looking only at radioactivity is good enough. I would very much like to know the deaths per kWh for energy produced from coal and nuclear energy. It is certainly possible that infrequent nuclear disasters are, well, worth it.

(A single airplane crash kills many more people than a single car crash. Airplanes are still much safer than cars since they crash so infrequently compared to cars. Nuclear energy might very well be in a similar position, I honestly don't know.)

Chernobyl killed 50 people immediately, and is estimated to have killed 4000 people worldwide from excess cancers. That's worst case, assuming there's no minimum threshold for radiation causing cancer. Some scientists think there is a threshold, which would drop the number quite a bit. There's too much statistical uncertainty to know for sure either way.

TMI is estimated to have caused only one excess cancer. So we're looking at 4000 people killed over the lifetime of nuclear power world-wide, compared to 24,000 people per year killed by pollution from coal, in the U.S. alone.

Coal accounts for 50% of the U.S. energy supply, compared to 8% for nuclear.

Chernobyl had much higher number of deaths.



The range mentioned is 14000-17000.

Can't read German. My source is Physics for Future Presidents by Richard Muller, a physics professor at Berkeley. He says that's the United Nations estimate.

Wikipedia also says the estimate is 4000, and references a report by the United Nations Scientific Committee of the Effects of Atomic Radiation. It goes on to say that UNSCEAR later decided that was an over-estimate, and that IAEA data corroborates that. It has citations for everything.


Even if the death toll was 17,000, that's still less than the number of U.S. deaths from coal each year.

Nuclear energy is actually the safest form of energy generation we have (in terms of "deaths per gigawatt-hour"), although wind and hydro energy is approximately the same. This is as presented by the ExternE project financed by the "EU Commission". "http://manhaz.cyf.gov.pl/manhaz/strona_konferencja_EAE-2001/... - Polenp~1.pdf"


Looks like nuclear is a huge win, even counting Chernobyl. Solar and Wind are also good power sources.

Nitrogen Dioxide is another harmful coal emission.

The writer is not an expert on earth quakes. Making such a bold claim that nothing can go wrong is plainly false. Just because they are an expert in one area, does not mean they are an expert in all areas.

There are already a number of people being treated for radiation poisoning. They have already admitted that there have been radiation releases above safe levels.

I feel sorry for the engineers working so hard to fix this, as they face the largest dangers. They are sacrificing a lot to save other people. As history tells us, in other nuclear disasters these are the first people to die from the affects. Some have already died.

A previous earthquake a few years ago caused an explosion in one of the reactors in Japan. I guess the costs and risks were weighed up - and the risks ignored. Previously the company CEO resigned because of falsified safety reports.

The costs of nuclear reactors - even if you don't factor in the costs of these disasters are higher now than other forms of cleaner energy generation. Let's use the smarter, more innovative, and safer energy solutions available today. Let's leave these 50's and 60's era shitty technology behind.

Let's use the smarter, more innovative, and safer energy solutions available today. Let's leave these 50's and 60's era shitty technology behind.

Oh, and what do you suggest? In the US, for example, we've just about dammed every river that can be dammed, and solar and wind are too expensive for wide scale deployments.

The only real alternative we have to the 20% of our energy which comes from nuclear would be to add to the 45% which comes from coal (or to the 23% from natural gas.) That would be a disaster, coal plants are far more damaging than nuclear plants are.

We should be doing the opposite. Replacing our alarmingly high coal energy usage with nuclear plants, instead. Too bad there's so much propaganda (and big-coal lobbying) against this. Nuclear is the only practical source of zero-emission energy for wide scale use.

Personally, I'd much rather live with a couple nuclear incidents than with the horrors of today's fossile fuel industries.

solar and wind are too expensive for wide scale deployments.

No, they aren't. And the only reason nuclear is considered "cheap" is that the costs of accidents and waste disposal are methodically underestimated.

Oh, and another thing: Uranium fuel is a quite limited resource as well...

We have 50 years of petroleum left and maybe 100-200 of coal. Compare that to centuries of Uranium, Plutonium and other radioactive minerals. Also, emissions are a big deal, too. Nuclear waste is contained and far less dangerous (when kept properly) than fossile fuel emissions.

I'm a long way from an opponent of nuclear power, but when you say

Nuclear waste is contained and far less dangerous (when kept properly) than fossile fuel emissions.

I think you might be making the opposite point to what you intend.

You compare the worst case of safety & long term consequences for oil/coal (ie, the current situation), with the best case ("when kept properly") for nuclear power.

A better comparison would be to compare the safety coal/oil power after spending the money required to keep nuclear waste safe on cleaning coal/oil emissions and improving mining safety, or else to compare the worst case in each scenario.

The worst case for coal/oil is a few thousand dead (from mining) a year, and bad climate damage. The worst case for nuclear is a few million dead and regional environmental catastrophe. It's fair to have a discussion about the probability any disaster happening, but to preclude the possibility undermines your argument.

To me, nuclear proponents making the case the nuclear is safe if everything goes well sound a lot like the NASA administrators who Feynman criticized in the challenger disaster report for not understanding risk.

Thorium isn't.

Yes, but major development is still needed to make such reactors safe and viable.

Sure. Major investment and infrastructure improvements are needed to make its alternatives viable too.

EDIT: I should note that even the above is somewhat irrelevant to my original point, which was simply that one cannot dismiss nuclear power as a whole simply because one type of fuel supply is "limited".

The problem with solar is that they require large amounts of resources to produce but also that they also produce the wrong type of power.

To give you an example, think of a way to run a large aluminium smelter overnight using just solar cells. There isn't any sun shining, so you arn't getting any power in. You need to somehow store enough energy to run the plant overnight, and do it in a form that can actually be produced, isn't absurdly expensive and isn't utterly dangerous.

And at the end of that, you need enough solar cells to produce enough power so that your countries economy doesn't stop in the first spat of bad weather.

I do agree with your point, however. Fossil fuels cause too much damage to the environment for them to be viable long term.

The only question is how do we go about replacing them, with the current political state of the issue?

Photovoltaics are indeed not very cost efficient right now, but solar thermal[1] is a much more mature, cheaper technology. It's also easier to store large amounts of heat than to store electricity.

[1] http://en.wikipedia.org/wiki/Solar_thermal

Solar thermal is in fact a very interesting technology. I've looked into the pilot plants over in the desert in california and it seems like a real step forward.

Its also interesting that they seem to solve parts of the "baseload power" problem, ie. some plants store molten salt and can thus generate power for extended periods, but they would still have issues. For example, in non-equitorial climates I would assume it would have diminished capacity in winter, which could be a problem if a large portion of the grid was composed of solar thermal plants. Similarly you have efficiency losses/etc. associated.

Considering that the only alternative in terms of storing power involves pumping water up hydroelectric dams, though, it's certainly a step in the right direction.

> Wrong type of power.

I don't think you explained this. It seems as though you're just arguing about the cost of batteries, not a certain "type" of power. (what types of power are there, anyways? I only know of one: electricity. There are many different ways to generate it though..)

The power for a particular grid generally has two components, that which is always on and that which fluctuates through the day. To give you an example, an aluminum smelter will always use a fixed (and very large) quantity of electricity, day or night, rain or shine. As it is impractical to store electricity anywhere near the scale required to power these types of buildings, you need a power plant that can provide cheaply a continuous supply of power. These are known as your base load power plants.

To show you that the storage of large quantities of is impractical by example, think of the last time you visited a data center, and remember the rows upon rows of of UPS batteries required to run one datacenter for a few minutes. It stands to reason that enough batteries to power the datacenter for an extended period of time (ie. days), would be utterly impractical. This is why datacenters have generators, ie. the batteries can't power the datanceter indefinitely and when the batteries run out, it needs to produce the power to power the datacenter.

[1] http://en.wikipedia.org/wiki/Base_load_power_plant

Aluminium smelters might be better placed somewhere with abundant power from sources like Hydro or Geothermal sources.

Or you could mine New York garbage and make diesel out of that.

Batteries don't actually store electricity. They convert electrical energy into chemical energy (and vice versa). I believe the "wrong type of power" referred to above was electrical vs. thermal energy, as well as delivery at the wrong time.

The Boston Globe this morning talked about people with acute radiation sickness, too. I don't know how much faith to put in that statement, but if it's true certainly the amount of radiation release is far, far greater than anything that this post envisions. In that case, he clearly can't be correct.

Let's use the smarter, more innovative, and safer energy solutions available today.

I agree. Let's replace all ~40-year-old reactors (like the ones breaking down in Japan) with modern, fail-safe nuclear designs.

Let's direct the money necessary for those into renewable energy instead.

Wow, such a denial of reality. 'in control'? If anything I saw in the last hours, the thing is not in control. Diesel generators failed, a building exploded, core meltdowns going on, restoring of electricity failed, seawater used for cooling (how were they pumping it and are the pumps powerful enough to provide cooling over a longer period of time like days). Valves are not working, measurement of pressure is not possible, there are fears of another explosion.

Two reactors are still OUT OF CONTROL.

One of them is even using Plutonium in its fuel. German news about that: http://www.spiegel.de/wissenschaft/technik/0,1518,750668,00....

Whether the containment will work as designed is unknown.

Fukushima II, the other plant has cooling problems, too.

Now there has been an alarm of higher radiation at the Onagawa plant.

German source: http://www.spiegel.de/panorama/0,1518,750637,00.html

The PhD from MIT failed to mention in his article, when he talks about the 3rd containment being concrete poured around the steel casing, that the reactor which caused an explosion was built prior to this 3rd containment layer being mandatory in BWR design. So, it would seem that his confidence in the 3rd containment layer preventing any melted radioactive materials from getting out should be taken with a huge grain of salt.

Updating with more information: Please see this list of BWR reactors throughout the world: http://en.wikipedia.org/wiki/List_of_boiling_water_reactors

You will notice that Fukushima Daiichi No. 1 (which caused the hydrogen explosion to the building walls) is a BWR/3, MK-1 model reactor. From this page, http://en.wikipedia.org/wiki/BWR#Evolution_of_the_BWR, you will see the following:

The first [General Electric] series of production BWRs evolved through 6 iterative design phases, each termed BWR/1 through BWR/6. (BWR/4s, BWR/5s, and BWR/6s are the most common types in service today.) The vast majority of BWRs in service throughout the world belong to one of these design phases.

1st generation BWR : BWR/1 with Mark-1 containment.

2nd generation BWRs : BWR/2, BWR/3 and some BWR/4 with Mark-I containment. Other BWR/4, and BWR/5 with Mark-II containment.

3rd generation BWRs : BWR/6 with Mark-III containment.

So, it would seem to me, that this confirms, it was not until at least BWR/4 or above that Mark-II containment was used. I'm pretty sure this confirms there is no 3rd containment layer.

This is the same impression I got from what I read so far. Unfortunately, it's pretty much impossible to get reliable information on that.

An announcement in Germany regarding the safety of our nuclear power plants stated that ours are supposed to be safer, because they would have at three to four safety layers instead of two used in Japan, which probably referred to the containment layers.

> Two reactors are still OUT OF CONTROL.

You may have noticed that they use defense-in-depth. Even though they were just hit by one of the biggest earthquakes ever and had several unthinkable things happen, there are still people inside the control room fixing it. If it were that "OUT OF CONTROL" that panic was required, they would have fled too.

Sure, the reactor may be expensive to clean up and it may be damaged enough that they'll retire it (it's a 40-year-old BWR design, after all), but years from now, we'll probably still be debating over exactly how much radiation was released, what sort, and whether it did anything. Just so you know, educated people will completely ignore alarming reports about radiation leakage that don't contain words like "Sievert." My professors would be remiss if I didn't.

But that's the problem with radiation. It's too invisible. Most causes of death can be seen and avoided. But radiation is invisible (except in a few weird circumstances) and it can linger in some cases, so people fear it as some kind of unavoidable, invisible poison.

Never mind the fact that it's all around us. Cosmic rays. Bananas. Background radiation is everywhere. It has been for your entire life and it's not going away.

I wonder if owning a Geiger counter would calm people down or just drive them away from Brazil nuts and potatoes? [1]

[1] https://secure.wikimedia.org/wikipedia/en/w/index.php?title=...

A few hours later we see that the reactor 2 of Fukushima 1 is severely damaged, radiation is leaking, most of the staff has been evacuated.

Yes, and you should expect more hydrogen explosions as long as they're forced to do venting. The measured radiation levels are approximately 4μSv/h.

"As of 0:30 pm, the measured value of radiation dose near MP6 was 4μSv/h. The increase of the radiation dose cannot be confirmed at this time.

As of 0:30 pm, the measured value of radiation dose at the monitoring post in Fukushima Daini Power Station located approximately 10 km south of Fukushima Daiichi Power Station remains at the same level.

In light of the incidents that have occurred at Units 1 and 3, we are considering applying prevention measures to the wall of the reactor building to ventilate the hydrogen gas contained in Unit 2."




The reactor 3 at the first Fukushima plant is not just using Uranium. It uses MOX fuel. So what the author ('expert???') wrote is already useless, he does not even know what the reactors are using as fuel.

Japan Today:


From August last year:

MOX fuel loaded into Tokyo Electric's old Fukushima reactor Sunday 22nd August, 05:36 AM JST

FUKUSHIMA — Tokyo Electric Power Co loaded plutonium-uranium mixed oxide fuel Saturday into a reactor at its nuclear power plant in Fukushima Prefecture in preparation for the largest Japanese utility’s first plutonium-thermal power generation.

The No. 3 reactor at the Fukushima No. 1 plant would be the third in Japan to be used for the so-called pluthermal generation, but the only one among the three to have been subjected to antiaging treatment with 34 years since its launch. Pluthermal output has already begun at the No. 3 reactor of Kyushu Electric Power Co’s Genkai plant in Saga Prefecture and the No. 3 reactor of Shikoku Electric Power Co’s Ikata plant in Ehime Prefecture.

Honestly, whether the fuel is UOX or MOX is not particularly relevant at this point, since the primary differences between those fuels are neutronic, not thermal, and even there they are qualitatively very similar.

I'm pretty sure the author is not an 'expert', exactly, because he seems unfamiliar with some of the nuances of BWR operation, but his summary is generally correct.

Sure it is relevant. It means that the level of Plutonium could be higher in reactor 3 of plant Fukushima 1. This could have relevance in case of a full meltdown. It is said that then there is a possibility that there is a different reaction.

You're rattling around various fora, throwing out really bad red herrings (e.g., on reddit you tried to link Niger's average life expectancy to uranium mining when that likely isn't even a blip on the radar compared to poverty, malnutrition and lack of health infrastructure). So the onus is on you to provide strong citations for the claims you're making, rather than just tossing out BIG SCARY CAPS in a comment and then hand-waving "could have relevance" and "it is said" when people engage with you.

Yeah, it seems to be surprising to you that there are people who did not drink the nuclear Kool-Aid. Why is that? Has your 2-party system, the influence of corporations and your declining media made you unable of critical thinking?

I can't speak for the previous poster, but I started 'sipping the nuclear kool-aid' once I took a nuclear physics class.

Of course, the class was taught over cable TV by fox news anchors funded by both GE, the DNC and the RNC. That's pretty much how the US got to be a superpower and stuff.

> I can't speak for the previous poster, but I started 'sipping the nuclear kool-aid' once I took a nuclear physics class.

Same here. And I think I know why: understanding the risks puts you in control, to some degree. People are highly averse to risks they cannot control.

I mean, the news is a joke. They talk about "radiation" but appear to have no idea how it's even measured. The news anchors don't seem to know what a Sievert is, nor why knowing that kind of stuff is important.

Superficial understanding of subject is worse than no understanding at all. People who blew up Chernobyl knew what Sievert is, and in fact possessed nuclear engineering degrees.

We've learned a lot since then. Reactors have proper containment vessels and negative (instead of positive) void coefficients these days.

And heck, as bad as Chernobyl was, they managed to operate the rest of the reactors for years after the accident.

Did not work out too well, given the history of nuclear power plants in the US. When was the last one built?

The list of cancelled nuclear power plants is impressive:


Cancelled nuclear plants probably have more to do with public relations then actual danger.

As an example, 4,000 people died in 2007 collecting coal for power plants, oil pipelines have a habit of https://secure.wikimedia.org/wikipedia/en/wiki/List_of_pipel... exploding, and tankers run aground, hydroelectric dams routinely kill off migrating fish and do damage to ecosystems. Solar cells require large amounts of toxic chemicals in their production and neither solar nor wind turbines can provide baseload energy reserves simply because the sun doesn't shine at night and the wind rarely blows the amount you need it to.

At the end of the day, we only really have three options for baseload energy: You have fossil fuels, hydroelectric or nuclear power. From what I can see, we are starting to run out of viable hydroelectric plants, fossil fuels are apparently causing widespread short term and long term damage to the environment, and nuclear power has gotten a lot better over the past few decades.

It is my opinion therefore that the view that nuclear power is horribly unsafe comes from the same sort of thinking that leads to the belief that planes are unsafe vs. cars, ie. that a small number of accidents make it to the news, simply because they are uncommon as opposed to lack of news coverage on the more dangerous subject simply because people dying of it is not news.

Case in point: How many news stories do you hear about "X died from terrorism" as opposed to "X died from a heart attack?". The latter is more likely to kill you, the former is the one people are more afraid of.

Meanwhile, hundreds of coal-fired plants were built in their stead, and those are currently spewing radioactive waste into the air in normal operation.

We hear nothing about the coal power plants currently.

The nuclear reactors seem to make much more trouble right now.

Coal-fired plants were not mentioned by me as an alternative or as desirable.

Please stop that.

I see that you are confused when somebody has not the view of the nuclear industry. You are brainwashed by the corporations. Even thinking that there are alternatives that are not coal seems to be not possible.

It does not matter what you happen to think are good alternatives or are desirable, because those of us who live in the real world have to deal with "what is", not "what could/should be." For base electric load in the US you really have three options: nuclear, coal, gas. One produces a lot of radioactive toxic waste over the course of normal operations, one produces lots of CO2, and the other is nuclear.

When will the US start with alternatives then? Never? How about some energy saving???

Slightly off topic but not really question;

Is there a defined term for the observation of continuous streams of information tailored to fit a particular popular ideology thus contributing to increased skepticism of said information?

I would say propaganda, but it does not always lead to increased scepticism unfortunately.

That's a good one actually, wrapped in another layer it works perfectly.

As there are code smells, so there are propaganda smells, but not everyone has a nose for either of them.


the lack of communication between TEPCO, Japanese govt and IAEA is a cause of serious concern as well, IMHO.

Great article. This seems to be a great story in the media because "normal people" are not as pessimistic as engineers, and see an explosion at a nuclear reactor to be something that is extremely bad and that could be ending the world soon. After all, atomic bombs are nuclear, and those are bad, right? But in reality, while not great, failures are accounted for in the design of the reactor, and can be managed.

It's sort of like driving your car into a concrete wall on the freeway. There are buckets of sand there that dissipate the energy; they get destroyed, but you and the freeway survive. This is the purpose of those sand buckets, to blow up to prevent other things from blowing up. The outer containment building is similar; it blows up, but the environment and the reactor core are still both fine. It would be better if it didn't blow up, but it is manageable because the engineers designed for that contingency.

Good for selling newspapers, but won't be ending the world just yet.

" but the environment and the reactor core are still both fine."

How confident are you in that statement?

As a fellow Tokyo resident, newly-minted quake survivor, and even fellow UFC aficionado, I found this guy's reprinted letter of explanation quite comforting. We've been kind of worrying about the nuke meltdown scenarios, and wondering if maybe we should find some pretext for a quick trip abroad in the next couple days.

And so I read this post, and nodded, and though 'Hmm, ok, good... OK, sounds reasonable. Oh, I see, great!'

And then I got to the end, and some little circuit in my brain switched on, and I realized I felt just a little bit too comforted.

As if this post, from a first-time blogger, might actually be the work product of some agent of the US pro-nuke consortium that's trying to get clearance (not to mention indemnification from liability) to build many billions of dollars worth of new plants in the US. Or, perhaps more plausibly, merely the comforting words of a family friend trying to reassure people who weren't really in a position to do much about things in any case. And whose dad works in the nuke industry, with whatever subconscious bias that might convey.

But hey, fuck it: taking that article at face value will make it easier to sleep tonight, so until morning at least I think I'll try to do that. So thanks for posting it!

There is a reason I feel much relieved after reading this. Pretty much everything I've read so far implied that once there is a meltdown, all bets are off. We'll have radioactive material boiling in open air, and all the "good" things that come with it. Which sounded very suspicious to me... I mean, isn't containment designed to prevent exactly that? Once the fuel melts, it just makes a hole on the bottom of the containment and pools on the floor? So for me, the money shot was here:

> For that purpose, a large and thick concrete basin is cast under the pressure vessel (the second containment), which is filled with graphite, all inside the third containment. This is the so-called “core catcher”. If the core melts and the pressure vessel bursts (and eventually melts), it will catch the molten fuel and everything else. It is built in such a way that the nuclear fuel will be spread out, so it can cool down.

edit: Plus reading about INES, there was a British plant that had 5 (five) level 4 incidents in 25 years, and a partial core meltdown at a French plant. And many more.

Except that "Fukushima Dai-ichi No.1 Reactor does not have a concrete containment dome. This reactor was built before the now familiar reinforced concrete dome became mandatory for most reactors. Instead, the reactor has a much smaller steel containment vessel around the reactor vessel."

This was from a Slashdot comment, so I trust it about equally to a newly minted blog with only a single post: http://slashdot.org/comments.pl?sid=2033910&cid=35463272

Someone with more knowledge of nuclear power history could surely cross reference the dates here for us and confirm/deny the existence of the 3rd containment layer:

Fukushima Daiichi Unit 1

- 439 MWe BWR, 1971

- Automatically shut down

- Water level decreasing

- Pressure release implemented

- Explosion observed

- Containment believed intact

- Seawater injection has started

- Radiation levels did not rise after explosion

Unit 2

- 760 MWe BWR, 1974

- Automatically shut down

- Water level lower but steady

- Preparations for pressure release

Unit 3

- 760 MWe BWR, 1976

- Automatically shut down

- Preparations for pressure release

Unit 4

- 760 MWe BWR, 1978

- Shut for periodic inspection

Unit 5

- 760 MWe BWR, 1978

- Shut for periodic inspection

Unit 6

- 1067 MWe BWR, 1979

- Shut for periodic inspection

Grateful for the explanation, but the author's bias is questionable at best. He suggests,

"If you want to stay informed, please forget the usual media outlets and consult the following websites"

and goes on to list 3 nuclear lobbying websites.

So, ignore the independent media and get all of your information from pro-nuclear lobbies?

More: https://morgsatlarge.wordpress.com/2011/03/13/why-i-am-not-w...

>So, ignore the independent media and get all of your information from pro-nuclear lobbies?

The msm usually doesn't have any idea what they're talking about when they report on computer related issues, why do you expect them to be any better when it comes to nuclear power?

He is not talking about msm but independent media. Mentioning Lobby groups as good information source discredits in my opinion the complete write-up. Also does the mentioning of "phd. scientist" ...

So according to your analogy: Don't listen to independent tech news, just listen to what Gruber tells you about Apple ;)

You wouldn't trust Greenpeace, you shouldn't trust the nuclear lobby. There are other independent sources available.

BraveNewClimate is definitely an advocacy site, but I think it's unfair to call the guy a lobbyist. Your own link says he's a climate scientist, and doesn't make any claims that he has financial ties to the nuclear industry.

The more I read about climate change and nuclear energy, the more pro-nuke I am. If I start writing up what I've learned on my blog, would you call me a lobbyist too?

I'm shocked, how can such a lobbyist piece be high-rated at Hacker News. I though the community would be more critical towards news in general.

There are several factual errors (so much I don't know where to start), just check the press releases from TEPCO, the public statements of the Japanese Government and other public available information (e.g. http://www2.jnes.go.jp/atom-db/en/trouble/individ/power/j/j2... )

The author does not know what he is talking about, his phD. won't help him there. (Everybody clear in their mind should wonder why smb. would start a piece with "phD. Scientist" I'm working in academia and I never mentioned my degree in any post here or elsewhere, because I want that my arguments convince and not my degree) It's the first blog-post of smb. who's linking just to nuclear energy lobbyist pages (telling you to prefer them over "standard media") and everybody starts up-voting the piece and down-voting negative and critical comments?

I thought hacker news was better.

"lobbyist" doesn't mean 'I disagree with this'. Using it as such is just low-grade conspiracy-theorising.

As I said, most information in the article is plain wrong. Starting with the 3rd compartment, over the type of nuclear material used to the safety measures of the company that owns the plant, etc.

Would you believe me, when I told you, "Disregard regular tech news, just listen to what Steve Jobs and Gruber tell you about Apple?"

I suppose that my fears for this particular situation are mostly allayed. But I think that's only the tip of the iceberg.

In the face of the world's need for energy, nuclear power is the only viable option that is available today. I wonder how much this incident is going to weigh against using that option?

The power plants in operation today use technology that's quite obsolete. The design of the older plants is an historical accident. Because of the war-driven necessity of developing nuclear technology for weapons, the understanding of the technology that informed the currently-operational reactors was largely bomb-centric. But we know better today, there exists designs for reactors that are orders of magnitude safer, both in terms of operational dangers as well as its waste byproducts.

I'm afraid that sound-byte driven media and activists who aren't willing to evaluate newer ideas will cause such prejudice that newer, better technology will never see the light of day, and thus we'll see worse environmental problems (or economic problems) because our current energy problems can't be fixed otherwise.

> ...nuclear power is the only viable option that is available today...

Nuclear power in itself is unlikely to solve our energy problems. It is only a part of the solution. We will not be able to supply the world with enough energy using nuclear power alone given the length of time it takes to design, approve, build, and certify a nuclear power station.

The Sun is by far our greatest source of energy.

Have a look at http://en.wikipedia.org/wiki/World_energy_resources_and_cons...

You'd be surprised at how quickly people can get things done if their lives are on the line.

We have more then enough thorium in the world to deal with the world's power demands (It's about as common as lead), we have much safer reactor designs created and tested, and we have thorium designs created and tested. It's just that there is a lot of politics and public opinion is not for nuclear power, it is very much for "green" power, which makes it not politically viable to create the number of nuclear plants needed supplant say coal/oil/gas fired power stations as our main supplier of baseload power.

The major problem with solar is that the sun goes down half of the day, there isn't any viable means to move power halfway across the world and there isn't any viable means to store anywhere near the amount of energy that is required to power a civilised country overnight.

Although academic, and with the possible exception of geothermal, astral energy is actually our only source of energy, albeit with differing latencies.

Fossil fuels contain energy from ancient biomass supported by the Sun, and heavy radioactive isotopes (like all heavy elements) are formed in supernovae.

What nuclear power needs is rebranding: call it Nuclear 2.0 or Green Thorium Power.

Strange... I didn't see this story on the new page and submitted after you and it posted a new version instead of auto-voting for yours. I didn't think HN would do that. Going to go delete that version now…

This is the most coherent description of the issues and events that I've read (and I've read a few). I learned a lot about BWR nuclear plants.

Some people here in Tokyo are starting to get very nervous and mostly that comes because nuclear power is so damn confusing. Understanding it can help you keep your wits. They are showing documentaries on Japanese TV about the cause of the tsunami right now but I think they should be showing "Nuclear Power 101" instead.

Edit: Another thing that is causing a lot of confusion is that there are two power plants that were affected (daiichi and daini) and each plant has multiple reactors. They were both operated by TEPCO as well so the press releases are coming from the same place. Keeping track of all of them is a bit confusing. This article is mostly about the most serious problem which is reactor one at daiichi.

Staying cool on the other side of the globe is far easier than living right next to it. So kudos!

It is hard to understand the technology behind it. Harder than just burst into cunfusion and condemning things. Every time I tried to get to know more about how nuclear reactors work, the more I found out, the more it calmed me down.

He says that even in the case of a total meltdown (which hopefully will not happen in Fukushima) we will be save because everything will be contained in the third containment.

What I don't get is how cooling is supposed to happen in this case. I think they still would have to pump sea water into the containment which would then get contaminated not only by neutron activation but also with Uranium, Cesium, Iodine etc.

What happens to the seawater then: Will it be released into the environment? Is it in liquid form or will it be released as steam?

You filter out the other elements, and release the water.

Water pretty much can't get radioactive. (For more than a few minutes.)

The longest radioactive oxygen you can make in a reactor has a half life of 26 seconds.

For hydrogen, deuterium is not radioactive, and tritium can't be made in a light water reactor.

So water effectively can't get radioactive.

That's why I wrote "get contaminated not only by neutron activation but also with Uranium, Cesium, Iodine". I doubt that in the current situation there would be the necessary facilities to filter out those elements, but I would be interested in having more information on this.

Well, the OP says there are such facilities. (The contaminated water can be kept in the containment till the facilities have recovered from the earthquake if they are currently down.)

As far as the steam is concerned this puts my mind at a rest. Quote from http://allthingsnuclear.org/post/3792741638/containment-at-f... "In this situation, the vented air would be routed through a high-efficiency particulate air (HEPA) filter, charcoal beds, and another HEPA filter to remove as much radioactivity as possible before being released from a very tall stack to dilute the flow as much as possible."

When you say the contaminated water can be kept in the containment, does that mean that they are basically flooding the containment with seawater? My impression was that the there is still a need for cooling (i.e. cool water in, hot water out) in case of a total melt down.

They are just flooding it and letting the water boil off.

If they could actually circulate water they wouldn't be in this situation.

Remember, they pump in salt water, without prior desalination. It will get radioactive, although to which extent I have no idea.

Not very.

The worst sodium has a half life of 15 hours.

The longest chlorine has a half life of 360,000 years, but is barely radioactive. The rest are all under an hour.

There's other stuff in sea water though. But not in large quantities.

And they have these filters right there, handy and ready to use just in case they started pumping in sea water?

Since they asked the prime minister for permission to pump sea water, I'm guessing that it was an option all along i.e. they have the facilities to do just a thing. The whole defence in depth concept relies on having a bazilion emergency options.

They could probably hack up a particle filter together pretty quick, but unlikely do any desalination. Any reactor which got salt water in it is very much totaled.

They don't have to use them till it's over.

The water is being boiled away, not circulated with pumps.

Excellent writeup.

I've been telling people this all day, but it's great to have a PhD confirm it.

BTW, with Chernobyl the control rods were not able to be inserted all the way, which is one of the main reasons it was so bad - the chain reaction never stopped, and the heat just kept building up.

While the article was a decent read, he is not an expert in this field. His work is in Supply Chain/Management


Where does he get his expertise in nuclear reactors? According to the article, his father.

"He is a PhD Scientist, whose father has extensive experience in Germany’s nuclear industry"

I agree, his expertise is not fully covering this field. But I think he's still far better informed than most voices we get to hear these days.

In Germany it took green-activists a couple of hours to organize nationwide protests. Politicians with no knowledge about physics beyond spelling "meltdown" are immediatly taking advantage of this situation.

On the one hand, our fear responses undoubtedly helped us survive when we had to worry about running away from big things with teeth. On the other hand, it also means that uninformed, power-hungry idiots like to boost their career by destroying things that would make life better for everybody.

It's true. This fear is what created the "Defense of Depth" in the first place (It may have been the absence of it, or the none-allowance of it, that enabled tchernobyl).

The ability to run when alerted by others seems to be a evolutionary proven advantage.

The ability to condemn those false intended alerters I think will pay back as an advantage too.

Actually that protest was planned some months ago. It just became so popular because of the recent events.

His work is in Supply Chain/Management

Well, his research and work have been in the area of risk management -- so I find it quite plausible he has access to detailed assessments of nuclear power plant liabilities.

It would be better if his PhD or his research were in a domain anywhere close to what he is talking about. Also, it would be better if the information he has where not only what is said in the news... People knowing what they talk about are really, really scared about the nuclear situation in Japan right now.

His PhD is in risk management and one or two of his publications are in waste disposal. I would rate his ability to accurately assess the risks inherent in the situation far higher than I would those of the news agencies.

As for the people that know what they're talking about, remember that you and the news organizations you're listening through are biased to make radioactivity scary stuff. For all we we know, our reflexes are giving their calm, everything-is-completely-under-control statements a disproportionately alarming cast.

The description he makes of how a plant works is nice, but being "a PhD" in an unrelated field doesn't mean much to me... if he had been a nuclear physicist with nice publications or nuclear engineer working at the xxx plant AND if he had access to additional information on what it's really happening/ed i would have cared more for his conclusions... Looking at the comments [1] (guy from Japanese Atomic Energy Agency) it even seems that he is describing a different configuration of nuclear plant (newer,safer).

[1] https://morgsatlarge.wordpress.com/2011/03/13/why-i-am-not-w...

Check out the other comments from Daniel on that post for additional info on procedures being put in action by the jp government.

Frankly I don't entirely credit the conclusions of any "authority" right now -- everyone outside the plant management loop is making educated guesses, and many of them have powerful institutional biases shaping their thinking.

And if we set aside conclusions, this is the best orientation to the problem that I've seen so far. I'm not worried about his credentials, as this is internally consistent, and externally consistent with what I know of physics. Maybe the plant lacks a third containment, or is using a different fuel, but I can adjust my understanding of the system for those facts as they come along.

Also Chernobyl uses graphite as a moderator instead of water. I.e. the chain reaction continued even after the water boiled away.

Also, from what I remember from the coverage at the time and right after, the graphite caught fire and the plume of smoke helped to carry even more fallout into the air and to spread it even farther.

Ive asked my Nuclear Fusion expert mate on this article and others, waiting to hear back and Ill post his response. He is currently working at the Department of Nuclear, Plasma and Radiological engineering at a US University, so I figure he'll know a thing or two.

Here's TLDR version: (1) the steam released has radioactivity lasting on the order of seconds, (2) if/when meltdown occurs, cesium/iodine radionuclides can exist in the steam but are apparently blown out to sea away from Japan, and (3) with the exception of controlled steam releases, a steel containment surrounding the core & related components will absolutely contain 100% of worst-case scenarios, meltdowns, etc.

At least that's how I understood it. Not an expert so I have no idea how much of it is true or not.

I am thinking about California's nuclear power plants. I figure that we will learn reasonable and effective ways to make them safer, perhaps ensure the diesel back generators are safe from a Tsunami. And this will cost money that we should spend. It is not like the California budget is swimming with money.

People talked about how strong this earthquake was, and it was strong, but the epicenter missed the power plants by quite a distance. Then we will get a surprise when a much smaller quake his one much worse.

This is a nice article, however: Breaking News: "U.S. Seventh Fleet moves ships, planes away from quake-hit Japanese nuclear plant after discovering low-level radioactive contamination"

I suggest you start worrying. More info here: http://www.nytimes.com/2011/03/14/world/asia/14plume.html

It was very interesting to read the wikipedia page for INES. Turns out we never heard about the most serious incidents except Cernobyl http://en.wikipedia.org/wiki/International_Nuclear_Event_Sca...

Interesting also that in the INES pdf on that site, the requirement for INES4 is at least one death from radiation. Perhaps the declaration of INES level four was in error, or the requirement is not strict. Another interesting link just found: http://en.wikipedia.org/wiki/List_of_civilian_nuclear_accide...

It looks to me like, on the wikipedia article at least, it's an "or" condition - probably the "Minor release of radioactive material unlikely to result in implementation of planned countermeasures other than local food controls." is what's triggering a level 4 event.

There is one confirmed death (a crane operator, but I didn't find any clear cause of death) and several injuries.

As he is already dead, it won't be radiation that killed him. Radiation poisoning needs days to do its ugly work. For the person to die within hours, the containment must have failed to allow sufficient radiation out. Since this has not happened, the person in question hasn't died from radiation.

The light from the Sun that strikes this planet, (the largest fusion based nuclear reactor in the Solar System) produces more energy in one day than all the nuclear, oil, or coal based power plants on the planet.

One has to wonder why governments insist on building poisonous, fragile, radioactive generators on earth, when we can safely harness solar, wind, and wave energies without such horrifying risk.

Will it be the lack of common sense that is cited as the primary downfall of civilization when we are long gone, due to our less than intelligent decisions about energy? Who among us wishes to have children play along the Gulf coast of the United States this summer? Oil illness anyone? Or along the coast of Northern Japan for the next 25,000 years or so...

Does anyone seriously believe that a "shoot for the moon" style campaign like the one we held to create nuclear power plants, would not result in workable alternative energy programs?

One point is certain. Earthquakes WILL continue to happen.

One other point is certain. Nuclear energy is inherently dangerous. You can only minimize the chance of catastrophic failure. Not eliminate it. And once the genie is out of the containment vessel, the penalty last 25,000+ years.

No amount of carefully considered analysis changes the science of this issue. It's time to give alternative energy solutions the same level of serious treatment we have lent to coal and nuclear systems or prepare for a future where meltdowns and frantic efforts to prevent them are more common place.

A future where more than a few locations become permanent exclusion zones for thousands of years. A future for your children where the increased incidence of cancer and mutation is part of every day living.

Or not if we come to our senses and throw every effort into fully developing alternate energy systems. We have a fusion reactor handy just 93 million miles away with billions of years of energy to come. Lets use it.

The reason people build power stations is that density of energy matters, not just quantity.

Sure, we can replace our current energy sources with solar + wind + wave.

What fraction of coastline needs to be covered with wave-driven generators, and what fraction of Earth's land area needs to be covered with solar or wind farms to get to our current energy generation levels? Last I saw the numbers for the US they weren't pretty.

Just to run the numbers for the US, average insolation for the Earth is 250W/m^2 according to <http://en.wikipedia.org/wiki/Insolation>. That's for the whole spectrum, not just whatever solar cells can actually use.

The land area of the US according to <http://en.wikipedia.org/wiki/United_States>; is a shade under 1e13m^2. That gives us a total of about 2.5e15W for solar power for the continental US, assuming your solar cells are amazing and have 100% efficiency across the full electromagnetic spectrum (as in, you've done an "Apollo Program" for solar cells and had amazing results).

Energy consumption in the US 5 years ago was about 29e15PWh/year, so about 3.3e12W.

So we'd need to entirely cover about .13% of the land area of the US in solar cells to get the amount of power we were using 5 years ago. We're using more now, of course.

That's about the area of Connecticut.

Now what's the useful life of solar cells? How high can we sensible expect to get it? How do we plan to handle the fact that the generation is ... very variable? How close to 100% efficiency do we think we can actually get solar cells? How noxious is the production process for these solar cells you'll have to be cranking out continuously to replace the failing ones, and where do you plan to locate it?

> Does anyone seriously believe that a "shoot for the moon" > style campaign like the one we held to create nuclear > power plants, would not result in workable alternative > energy programs?

Yes. I don't think such a campaign would get us to the point where we could use any combination of wind, solar, wave for baseline power.

> Nuclear energy is inherently dangerous.

So are solar cell production facilities. So is swimming, for that matter; the question is one of probabilities.

> the penalty last 25,000+ years.

How long does the "penalty" for a serious chemical spill last?

> No amount of carefully considered analysis changes the > science of this issue.

This much we agree on. ;)

2/3rds of the earth is covered with water, Nothing would prevent putting solar on the oceans surface. And why would we cover land with panels, when we have rooftops that cover triple the area required to generate the base line you cite? Already, flexible rooftop material exist that serves a dual purpose of protecting the home, and producing power.

Every problem you cite can be solved readily. Put even a 100th of the resources expended to develop nuclear energy into alternate energies and we can be rid of the suicidal methodology of nuclear energy on the planets surface. Why anyone would defend something as poisonous as nuclear energy is beyond understanding. It is a continuous threat to the future of the species and supported only by those who stand to profit greatly from its deployment.

I don't think you actually understand the science at all.

"Every problem you cite can be solved readily."

... by the simple technique of ignoring our limited resources and engineering skill, yes, sure. Solving them for real is somewhat more challenging. Your ideas are so far-out (a polite way of saying "stupid") that based on experience an explanation of why they won't work will simply be ignored by you. You are off by orders of magnitude, plural.

How much has been spent on nuclear energy in the way of resources, exactly? I'd like to see a citation here. And a comparison to spending on solar.

I note that you carefully ignored the issues of baseline power generation needs (e.g. the sun does not shine all the time) issues of power transmission from the middle of the ocean in your ocean proposal, the fact that putting solar in the ocean will significantly reduce the panel's useful life, and a host of other issues.

I'm quite prepared to believe I don't understand the science, but please don't pretend like you do. Handwaving serious problems away with "oh, if we just throw lots of money at them they'll disappear" is not "science".

Suppose you could engineer structures large enough to float enough solar panels on the ocean. How do you transport the energy to where it's needed? How do you clean the panels from bird shit?

> The light from the Sun that strikes this planet, (the largest fusion based nuclear reactor in the Solar System) produces more energy in one day than all the nuclear, oil, or coal based power plants on the planet.

I live in Seattle, you insensitive clod.

Unfortunately good will isn't the strongest driving factor in all this, it's a whole lot of paychecks, and solar energy is still behind.

25 years after chernobyl, we still find contaminated material in germany. e.g. mushrooms and wild boar. so i would be VERY carful with such a bold statement as in the linked article.


"And the willingness to eat contaminated venison has dropped obviously, more and more hunters and forest owners can check the meat of wild boars - and compensation from the Federal Ministry of Environment, if they can not eat the contaminated venison because of the large cesium-137 content or sell.

€ 424 650 paid by the Federal Ministry of Environment last year for it. In the first half of 2010, the amount of compensation was 130,000 euros. 2008 there were 380,000 euros and 104,000 euros in 2007."

Thats when different radioactive material than in this case in much higher amounts was lifted to high altitudes, which also didn't happen here.

I'd be very careful to compare this incident with Chernobyl

FTA: "Some radiation was released when the pressure vessel was vented. All radioactive isotopes from the activated steam have gone (decayed). A very small amount of Cesium was released, as well as Iodine. If you were sitting on top of the plants’ chimney when they were venting, you should probably give up smoking to return to your former life expectancy. The Cesium and Iodine isotopes were carried out to the sea and will never be seen again."

And my main point is not that i want to set the japanese accident on the same level as chernobyl, but more to make clear that nobody expected such a strong contamination after 25 years thousands of miles away from the center of explosion. World is not behaving linearly, even though some people want us to believe it does.

This is a very well-written article. In the end, the author provides a nice collection of links to usable resources.

If you want to stay informed, please forget the usual media outlets and consult the following websites:




Ouch, I should have checked those resources more carefully.

I'll add this here as well: a diagram of how these reactors are built is in this book: http://books.google.com/books?id=y20F8Yt6UcMC&pg=PA34...

Data folks, data.

If anyone wants to read a much more thorough technical analysis of all the reactors at Fukushima Daiichi and Fukushima Daini, as well as a great analysis of what has happened, I found this page has some great info:


Since the author seems so certain that the third containment shell would hold the meltdown safely, and explosions keep happening: Can someone answer me why won't they just allow it to melt down, so they can clean up the rest and get the whole nuclear plant back online? Is it just an economical reason? Or is there any other risk?

This is not completely relevant to the current topic, but I was wondering if any video exists of the inside of a nuclear reactor. What does it look like when it's running? A brief search on Youtube could not locate anything.

dunno about actual run-of-the-mill daily cycle but I've seen the reactor at K-State run a couple-dollar pulse. It looked about like this: http://www.youtube.com/watch?v=mgNwtepP-6M

For the day to day operation it just looked like a big pool of distilled water with a ton of pipes running around in it.

The Cherenkov radiation in that video is worth a watch if you haven't seen it before. Apparently the water contains the radiation. The effect is from the electrons passing through the water faster than the speed of light could be in the water.

I don't think any cameras would survive in there. They're inferring what's going on based on sensor readings.

interesting: the site moved, now the commentary section is turned off (wondering why). "The article is mostly correct ..." and "In theory we should be more worried about the ash radiation from our coal plants ..." are still the highest rated comments :(

Hoping for the best for my friends in Tokyo and the rest of Japan.

good comment from there:

I wonder how the news that two reactors are in partial meltdown, six out of ten are without any cooling and in the japanese prefecture of Miyagi Sunday radiation levels 400 times above normal have been measured fit in your “analysis” that the situation is now under control.

do people really need to jump to conclusions as the situation is still in development?

Logarithmic scales tho', innit. Is 400x actually significant?

Remember at Three Mile Island everyone got a dose of radiation that you'd get going to the dentist, and that's considered to be a "disaster".

my guess: 400 times the daily dose is what you would get from natural radiation in a year. This amounts to about 2 milli Sievert depending on where you live. Articifial radiation of which 95% comes from medical scans is also about 2 mSv.

So the dose recieved is the same as the average person gets a year in medical scans. So those people in the area shouldn't have a scan next year.

The negative effects on health from these levels of radiation are in increased risk of cancer.

To suffer from direct radiation poisoning, the those would have to be many orders stronger. In Chernobyl, this happened to the firefighters on site without protective clothing and an exposed and active core.

All in all, the risks for the population so far a very minimal apart from the increased risk of cancer.

i like it when scientists say "the situation is under control" after the roof was bombed off.

You should have read the article which explains why this explosion wasn't nearly as dangerous as it seemed to be.

And you should read this: http://www.nytimes.com/2011/03/14/world/asia/14plume.html

If the US Navy is fleeing for cover 60 miles away from the reactors, the situation is SERIOUS.

While I'm not really calmed by the original article ("my father has nuclear experience"), I'd suggest that it may be just a case of them not being really needed in the area, and moving just in case.

No, it doesn't have to be. The natural reaction to any nuclear threat is to over-react :)

it's the first post on his blog and we are certain he is no lobbyist. citing foreign experts you happen to know personally somehow is commonly used in popular science literature.

a catastrophe not as bad as chernobyl can still be pretty bad.

> and we are certain he is no lobbyist

Are we?


There are many really dangerous things going on there, but the explosion was relatively harmless.

With all that coastline Japan should be investing more in tidal power generation and forget once and for all about nuclear power, too high the risk for earthquakes and tsunamis happening again even at worse scale.

Can tidal power equipment survive a tsunami, though? Japan needs a stable energy supply – if only because they can’t just import power from one of their neighbors in a pinch (like, for example, most European countries can). I heard today that even wind turbines are not ideal for Japan because typhoons are common.

Japan is in a pretty unique position – it’s certainly understandable why nuclear power is very popular there.

I hope it remains popular. I know, this is a disaster, but the reactors at risk are old steam-engine types. Comparing this to modern reactors is similar to comparing an old steam-locomotive boiler explosion to a modern formula racecar.

e.g. http://www.nuscalepower.com

How, exactly, is this a disaster compared to the greater surroundings? Preliminary results are one death, some injured people and perhaps 10 people who'll die from cancer in 20 years time who otherwise wouldn't. Compare to the thousands deaths, millions homeless and unimaginable damage from the earthquake and the nuclear 'disaster' is but a drop in the ocean.

One way its a disaster is, if it warps public policy for decades to come, armtwists power providers into dirty, ecologically disastrous choices and impoverishes a nation thru expensive energy.

Earthquake destroys nuclear plant: thousands killed.

Tsunami destroys tidal power plant: none killed.

You are the PM of Japan, you make the call.

Actually, hydroelectric plant failures can cause 100+ kilodeaths. In terms of prompt fatalities, hydroelectricity is by far the deadliest power source.

Am I right in thinking that your figure is for inland hydroelectric power plants, not Tidal power generators?

I would be interested in how tidal generators can cause >100.000 deaths.

As of yet, no one was killed during the nuclear incident.

Weren't some engineers already killed during the explosion?

The one death reported so far was when the earthquake hit and he got crushed by a crane.

did the earthquake kill thousands, or did the total failure of a nuclear power plant kill them?

a tsunami can kill just as many people as an earth quake.

the subsequent deaths due to a destroyed power plant are another matter. from the article I get the impression that nuclear plants are built to withstand a lot of abuse and fuckups.

i see no reason to shy away from nuclear power. their power producing companies will know what kind of plants to run. we don't.

This is a company that has been caught falsifying safety reports, and had resignations because of it. I would not trust them to choose in the interest of everyone - but instead in the interest of the company.

> This is a company that has been caught falsifying safety reports, and had resignations because of it.

That's highly encouraging. That means that caught the people falsifying the reports and that they fired them.

If they had a "perfect" record, I would be incredibly worried.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact