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Germany shuts down seven reactors‎ because of Fokushima (reuters.com)
77 points by y0ghur7_xxx on March 15, 2011 | hide | past | favorite | 132 comments



This strikes me more as a political stunt by Merkel to rally the conservative base in Germany than anything else.

Still, it doesn't surprise me that this is such a hot button issue right now. I've long been a supporter of nuclear power, but the events of the past week have made me start to reconsider a lot of my beliefs about its safety.


Which beliefs? That a nuclear power station situated in a major earthquake zone next to the coast could magically survive a 9.0 earthquake and a tsunami?

Right now, we don't know how serious this situation is, it could be that this will end with a small amount of radiation leaked and four reactors that have to be decommissioned. Or it could end with a major environmental disaster. We simply don't know yet.

I'd caution calm and not following in the footsteps of Germany. Let's wait and see. In a few weeks we may be reconsidering nuclear power, or we may be marveling at how well those plants survived what happened to them.


I've done a ridiculous amount of reading the past few days, and I still believe that nuclear power is probably the best source of power that we have available to us.

But I didn't realize that keeping a reactor vessel (and fuel storage pools) cool after the reactor has been scrammed is such a challenge. I also didn't know that hydrogen explosions are a normal byproduct of cooling down a reactor core. Yes, I know that there are third generation reactor technologies available today that don't have all of these issues, and fourth generation technologies in development. I really do believe that we should be investing in these technologies to make nuclear power safer.

Unfortunately now we're stuck with a lot of aging reactors that are operating past their design life, and a public that is unwilling to bear the cost of the upgrades.

Japan is probably about the best prepared place that this incident could happen, and even they are having trouble keeping their scrammed reactors cool. And another earthquake could happen tomorrow, making the situation even more unmanageable.

I have far less confidence in almost any other country being able to handle a crisis like this. Nuclear power is clearly here to stay - Germany may eventually turn it's back on the technology, but there are dozens of third world countries running reactors now (or trying to).

Our focus really should be on making nuclear power as safe as possible, not on preventing it entirely. Perhaps the biggest problem with this current crisis is that it is the first nuclear incident where we can't just explain it away as 'human error'. Everything did work exactly as it was designed to, with the best trained people handling the crisis, and we still can't have complete confidence in the technology to cool itself off without releasing radiation into the environment.


"I really do believe that we should be investing in these technologies to make nuclear power safer."

This is my major beef with nuclear power. We could invest scads of dollars into expensive and fairly mature nuclear technology, or we can put that same amount of money into renewables which have tremendous room for improvement (that and money towards the advanced power grid that would make renewables also more efficient). I think it is a mistake to neglect the opportunity to shift focus.


Nuclear technology has a lot of room for improvement, too. There's some improvement that's relatively straightforward, like bringing capital costs down; China is working on this, with great success, as they can now construct CPR1000 plants cheaper than coal plants of the same size.

Then we have more exotic and longer-range options, like breeder reactors (both uranium and thorium), small modular reactors, Brayton-cycle gas turbines instead of steam turbines, and so on. Nuclear technology seems stagnant, but the reasons for this are political rather than technical, and that's changing now.

Edit: I forgot to mention clever applications that are possible without reactor modifications, like high-temperature hydrogen production, ammonia synthesis, desalination with waste heat, and so on.


You know, even if the opportunities for improvement were equal (and that is far from the case; solar power improvements look to be improving by an order of magnitude in the near term, for example), renewables still enjoy a massive safety advantage. So I say save the money and invest in something less fraught with hidden and/or potentially catastrophic costs.

Fact is, even in this still-not-disastrous scenario, there are people working frantically trying to contain the reactors, risking radiation exposure and harm from explosions. If one hundred windmills had fallen over, or 100 solar panels been cracked, there would be no urgency, and the hardware could be replaced easily when it was safe to do so.


"I've done a ridiculous amount of reading the past few days, and I still believe that nuclear power is probably the best source of power that we have available to us."

The best source of power that we have is to use energy more efficiently.


Efficiency only goes so far. There are billions of people in the world who use very little electricity, and soon they're all going to want huge TVs, electric stoves, washers and dryers, water heaters, air conditioners... for which enough power cannot be provided by simply using less of what we already produce. We will have to increase production.


Thats untrue. In his 2009 Ted Speech Bill Gates shows pretty easy why that idea is not realistic: http://www.ted.com/talks/bill_gates.html


Energy efficiency only goes so far when we're pushing to power more transportation off of the electrical grid as well.


Magically? We're made to believe that nuclear power plants are built for all sorts of compounding contingencies. Take a look at the list of significant earthquakes in Japan:

http://en.wikipedia.org/wiki/List_of_earthquakes_in_Japan

8,3, 8.5 and 8.4 are three major earthquakes I see before mid-20th century. If you're building a power plant, it should survive a large safety factor above the largest earthquake you have ever seen, especially since the cost of failure is pretty darn high. I don't think it's unreasonable to expect to survive an 8.9 in a major earthquake zone, especially since the largest earthquake the world saw after the 1900s was around 9.5.

I think the fact that the diesels in Daiichi failed because of seawater flooding is yet another gigantic contingency failure. The Japanese know that earthquakes are followed by Tsunamis. What happened?

I used to be pro-nuclear but I'm reconsidering my decisions too. I don't think that humans can be trusted with doing things right, such as decommissioning old plants in time or building in extra safety factors even though it costs way more money to do so. Furthermore, I shudder to think what a deliberate attack attempt at a nuclear plant (or several ones simultaneously) could do. If there are people who drive planes into buildings with no regard to their own life, there will be those who attack nuclear plants also.

Edit: reasons for downvotes would be appreciated to further the discussion.


Looking up in http://en.wikipedia.org/wiki/Richter_magnitude_scale the Richter Scale "is a base-10 logarithmic scale obtained by calculating the logarithm of the combined horizontal amplitude (shaking amplitude) ...". This means that a Richter magnitude of 9 has a 10 time bigger shaking amplitude than Richter magnitude 8. I do not know for which earthquake magnitude the power plants in Japan were planned but apparently the risk assessment was not good enough.

This said, I am opposed to nuclear power - I think that apart the natural catastrophe risks, as you said there is human error that cannot be calculated, there is no "clean" solution for the nuclear waste and again we are relying on radioactive materials that are limited so anyway mankind will have to look for other solutions. I think it is high time to make an effort and look for other solutions.


Note that the richter scale is outdated, the current scale (while sometimes mis-named Richter) is the Moment Magnitude Scale.

It is also a logarithmic scale.

Furthermore, as with Richter,

> This means that a Richter magnitude of 9 has a 10 time bigger shaking amplitude than Richter magnitude 8

Yes, and a bit above 30 times the energy released (2 magnitudes indicate a thousandfold increase in energy)


Yes, but I think makmanalp point was that earthquakes of up to 8.9 are not unknown in Japan, and there's also been a 9.5 in the world. Thus it would be reasonable to expect 9+ earthquakes and tsunamis in Japan.

Now, can you make anything withstand that? I am not sure, but I think it is possible. It would make electrical power more expensive but how much would more expensive electricity shave of Japan's GDP? Enough to justify not doing it?


I think saying "magically survive" is being uncharitable to bhousel. What it has made me reconsider is the notion that even if we're able to design a system to withstand the problems we do foresee, it still may fail because of the problems we don't foresee or considered too unlikely.

I know this is almost a tautology, but when the stakes are as high as a nuclear powerplant, it's important to consider. Nuclear powerplants are the poster-child of massively redundant fail-safes. If we (as a species) are not able to design a system to withstand natural disasters when we know the stakes are as high as possible, then maybe we shouldn't play that game. While a massive tsunami is rare, it's not necessarily rare on the time scale that we expect nuclear plants to be operational. Given our track record, perhaps we can expect a serious problem once every 50 years. That's really infrequent - but it still might be too frequent considering the consequences.

I haven't come to any conclusions, and I don't think bhousel has, either. But the past few days have given us more data to churn on.


And if we discover that, short of an asteroid impact, the worst case scenario is that we end up with a sealed containment vessel which has to sit on site for 10 years to cool off and then cleaned up and disposed of. What does that say?

I think in the context of 'major disaster' if the nuclear plant's core stops being usable as a power plant but otherwise has contributes little to the final cleanup, that would suggest to me that its a good strategy.


The real tragedy here is that while it's almost certain no civilians will die from radiation poisoning in this case, there quite likely will be or have already been deaths stemming from lack of electrical power.

But people dying from illness from lack of clean water because their water treatment plant is offline and their hospital is out of emergency power doesn't get TV ratings, pageviews, and political attention like apocalyptic visions of radioactive fallout.


No, the real tragedy is the now estimated >10,000 people dead from the tsunami and earthquake itself.

That said, I don't get your point. It's not like they could run the reactors if they wanted to. Those people you are talking about are dying because a natural disaster took out the entire infrastructure. That's totally independent of what's going on at the nuclear plants.

Besides, by what knowledge are you claiming that it's "almost certain" noone will die?


Yes, certainly the initial loss of life is the worst part of this. But there are still many more lives at risk, and not from radiation.

The radiation most civilians see from a BWR steam release will be measured in microsieverts -- one CT scan equals thousands of those. The cleanup workers are going to be at higher risk, but I think it's safe to say none of them will die from the doses they are receiving. Ultimately, the danger from radiation in this case is vastly outweighed by the other dangers associated with a flooded area with no power, and that's what is so unfortunate about the media coverage about Fukushima; it's overshadowing the real ongoing danger to human lives.


As we can see in this discussion, what happens at Fukushima may impact nuclear policy throughout the globe.


The loss of power is actually one of the aspects of the situation that I find especially tragic.

The USS Ronald Reagan is only 100 miles offshore and has its own nuclear power plant that could be tied into the local grid to provide emergency power to things like the water treatment plants, hospitals, and even the cooling system at the Fukushima Dai-ichi facility.

I know the details of parking an aircraft carrier outside a devastated port city and plugging it into the grid aren't trivial, but I wonder if it's something that's been considered?

FWIW: some great discussion here: http://message.snopes.com/showthread.php?t=52136


The problem would be that of matching frequency and phase with the mainland grid. The Kantou, Touhoku, and Hokkaidou area grids run at 50hz, unlike the North American standard of 60hz - so if the ship is using 60hz they'd have to convert to DC and back to AC; this conversion equipment may not be easily available immediately. Even if the frequency matches, you'd need to match phase with the grid as a whole (or intentionally isolate the segment of the grid you're powering). It's safe to say the reactors in an aircraft carrier aren't designed with phase adjustment in mind.

You'd also need some very heavy duty cables to link to the ship's internal grid. And there's no guarantee that the ship would have enough sheer power to do something like that. Moreover, if the local grid itself is devastated, you have nothing to plug into in the first place...


Yeah, it's no small task, but definitely possible. Japan's electrical grid actually operates at both 50hz some places and 60hz in other places, so it's likely that they have the equipment somewhere that could be flown in by helicopter to make it happen.

The electrical engineer in me is fascinated by this stuff, so I submitted a new topic. Maybe people more knowledgeable will comment: http://news.ycombinator.com/item?id=2327908


They do indeed have some conversion stations, but these stations are already working at full capacity trying to support the kantou area grid (which is having rolling blackouts due to power plant shutdowns). They're also probably not very portable.


This sounds good in theory, but I doubt there's even a functioning grid to plug into. If the grid was ok, they surely would have been able to bring in at least some amount of power from unharmed areas.


...there quite likely will be or have already been deaths stemming from lack of electrical power.

Last I heard the rolling blackouts were not needed because everyone voluntarily reduced power use. Also planed rolling blackout are designed to be as safe as possible.

But people dying from illness from lack of clean water because their water treatment plant is offline and their hospital is out of emergency power..

This is Japan we're talking about, not Haiti.

The tsunami hit, it was a huge tragedy, but it is over and people are recovering. The nuclear disaster on the other hand is happening as we speak. Naturally people are more interested in the ongoing danger with a great range of possible outcomes.


The nuclear power plants in Germany are a mess. Negative findings of investigations magically disappear, threats like earth quakes are simply ignored. The pre-defined runtimes are exceeded and still most of them are running. Turning these off is reasonable. It was without the Japan Desaster and still is.


Nuclear disasters are so rare that a single data point of the magnitude of damage provides so much information on our risk assessment of nuclear power that it seems reasonable to idle plants while we wait and see how this one plays out. This is only the third major issue to ever happen.

Waiting this one out doesn't tell us more about the frequency of occurrence (it already occurred), but it does tell us about the magnitude of damage, which is one of the biggest unknowns and arguably why the US caps nuclear plant liability at ~12 billion via http://en.wikipedia.org/wiki/Price%E2%80%93Anderson_Nuclear_... .

The overt reason was that it was such an unknown that no one could insure it; a cynic might say that the cap was known to be incredibly low from the outset, and it was really just a hidden subsidy towards the creation of fuel for more and more nuclear weapons (this was the late 50s).


One nuclear disasters is one too many. If we can't engineer and operate a zero fail nuclear power-plant including various natural desaster scenarios maybe we should not use such technology.


Why would this standard be applied only to nuclear power? Would you say the same about aviation, oil production, dams, or any other highly useful but occasionally dangerous technology?


Nuclear Plant vs. 9.0 Earthquake & Tsunami.

I honestly wouldn't have bet on the Nuclear Plant only a week ago.

I'll add that besides the headlines, Thailand is considering to cancel its 5 plants project. Fortunately, this simply means lobbying will be a bit more expensive.


Considering hindsight bias, it's difficult to really know what we would have considered likely.


> That a nuclear power station situation in a major earthquake zone next to the coast could magically survive a 9.0 earthquake and a tsunami?

The un-posed question is "what happens if a group of terrorists fly an A380 directly into one of these plants"? Someone on reddit was mentioning that a nuclear plant in Texas was built to "withstand a direct hit from an F-16 traveling at supersonic speeds", but I guess an A380 is so much heavier and larger than a F-16. Because right now terrorists don't even need to get access to the US aerial space, they can hit a nuclear plant in Mexic (let's say this one http://en.wikipedia.org/wiki/Laguna_Verde_Nuclear_Power_Stat...) and still be able to cause important damage to the US population.

Here's the reddit comment I was talking about: http://www.reddit.com/r/pics/comments/g3tfr/and_you_are_tell...


K=1/2*mv^2?

My intuition (as a mechanical engineer, desinging military systems as my day job) is that the F16 going supersonic is far worse. Either way, there is no possible way you have enough information to make any of the claims you just made.

A better question to ask yourself how safe your highway transportation is, because within an hour of my house we've had 15 people killed in bus accidents in the last 72 hours. And that doesn't even begin to count car accidents. I live within 5 miles of over 10 nuclear reactors and they have never and will never scare me because I actually understand the engineering behind them. Nuclear power is not magic. Small doses of radiation scare me far less than the concussions I get from sports I play.


> Either way, there is no possible way you have enough information to make any of the claims you just made.

I took out this from this report (http://www.euronuclear.org/reflections/nuclear-facilities.ht...), which I think was also mentioned by jgrahamc:

> The studies showed that even if knowledgeable insiders could disable key safety equipment, redundant systems would provide backup protection. In scenarios where all engineered safety systems were ruined, there was still a period of hours to take corrective actions before onset of core damage.

Now, you may argue that what indeed went wrong in the case of the Fukushima plant was that the "redundant systems" didn't provide the "backup protection" the experts relied on. I see this report is confident this would not be the case were the terrorists to hit a nuclear plant, but based on what happened in the last few days I'd say the confidence level for that scenario is bellow 100%.

Anyway, thx for those downvotting me, and I hope I'll never be proven right.


The backup generators that they bought on site had the wrong types of plugs on them.

When this is all done, I am sure that most of the problems at Fukishima will be found to be administrative rather than design.

As an aside, that plant was designed to withstand an 8.4 earthquake. Design requirements and actual strength are two different issues. Even a complete meltdown, such as at Three Mile Island, should be contained.


'had the wrong types of plugs on them'

I have seen this as one of the biggest failures so far.


Huh? The mass of the A380 is at least 100 (and perhaps 1000) times the mass of the F16 (just picture them flying side-by-side and note the area of sky obscured by the A380 versus the F16 and note that although the mass density of the F16 might be higher than the A380 because much more of the mass is engine, it is not twice as dense as the A380).

And no way can the F16 go 10 times as fast as the A380.

So the kinetic energy of the A380 is definitely higher, probably by a considerable amount.


Weight (Maximum take off)

  A380 = 569000 kg [1]

  F-16 = 19200 kg [2]
Top Speed

  A380 = 945 km/h = 262.5 m / s

  F-16 =  2410 km/h = 669.444444 m / s

Kinetic Energy

  E = 0.5 * m * (v^2)

  E380 = 0.5 * 569000* (262.5^2) = 19 603 828 125

  EF16 = 0.5 * 19200 * (669.444444^2) = 4.30229629 × 10^9

[1] http://en.wikipedia.org/wiki/A380

[2] http://en.wikipedia.org/wiki/F-16_Fighting_Falcon

That said I think it probably doesn't matter. On impact the plane would breakup and you probably wouldn't get full force from either and also I bet it was built with more then a factor of 10 safety factor.


My intuition says you are wrong. But I am just a person who liked his high school physics class 10 years ago.

http://en.wikipedia.org/wiki/Airbus_A380

http://en.wikipedia.org/wiki/General_Dynamics_F-16_Fighting_...

A380 typical operating weight: 600,000 lb

F16 Loaded weight: 26,500 lb

A380 Max Speed: 580 MPH

F 16 Max Speed: 1500 MPH

Airbus weight advantage ~= factor of 30

F 16 speed advantage ~= factor of 3

3 ^ 2 < 30

Maybe there is some destructive value in having the kinetic energy more concentrated in the F16, but a full speed A380 has a lot more kinetic energy than a full speed F16.


Say you were to use a pebble bed reactor (Modern aircraft, modern reactor).

The reactor is designed in such a way that in case of coolant failure/containment failure/etc. the pebbles equilibrate at a stable containable temperature, and as such even if you could obliterate the reactor itself, the pebbles wouldn't melt down and as such wouldn't contaminate the environment with radioactive waste. Similarly as the coolant is helium, it is less radioactive in normal use and as such the coolant leak wouldn't be a critical disaster.

The pebbles themselves are coated in silicon carbide and as such are probably hard enough that you could use them as impactors against softer targets like, say, tanks. Due to this hardness it is thus unlikely that you would damage a large number of pebbles and hence release a large amount of core material.

Disclaimer: I'm not a nuclear scientist, I just think it's freaking cool.


You might enjoy reading "Deterring Terrorism: Aircraft Crash Impact Analyses Demonstrate Nuclear Power Plant’s Structural Strength"

http://www.nei.org/filefolder/EPRI_Nuclear_Plant_Structural_...


KE = 1/2mv^2, so depending on how supersonic they're talking about, it could very well withstand an A380 impact as well as a supersonic F16.


Supposedly an A380 carries much more fuel, whose explosive power might make up for the difference in impact speed.


The fuel is a fire risk, not an explosion risk. To get a decent explosion you would need to mix the fuel with a lot of air in the right ratio. Real life is not like the movies/TV; sealed tanks of gas are unlikely to explode if punctured by flaming debris. As an example, the fuel in the planes is what eventually killed the WTC buildings, but this was because the fuel burned, not because it exploded.


One thing that is moderately interesting is that tsunamis can happen without earthquakes - Scotland was stuck by a 20m tsunami about 6000BC due to an underwater landslide off Norway.

I did find myself wondering if the impressively engineered AGR site at Torness would survive a 20m tsunami - almost certainly not as I suspect this wasn't part of the requirements.


Why? I actually think the events of the past week prove it's safety. Let put it in perspective: a 40 year old nuclear reactor gets hit by a 9 magnitude earthquake, then slammed with 20 ft. tall swell of water, followed by an explosion due to the buildup of hydrogen gas that blows off the roof of the building, and after all that the core was still mostly intact and contained. That seems like an amazingly positive result to me.


What potentially devastating consequences would there be if instead of a nuclear plant a windmill had been hit by an earthquake, tsunami and explosion? I honestly fail to be impressed by this kind of reasoning about nuclear energy's safety.

Disclaimer: I still think fission power might be better in the long run than coal power (catastrophic global warming is worse than any nuclear disaster), but I'd rather do without either and strive for 100% renewable energies. It can be done, just needs the willingness to do it.


The problem is that you can't (currently) replace that nuclear plant with a Windmill (or even a few Windmills) because the power production is still not high enough.

So I don't feel that is an entirely fair comparison.

What if such an event had hit, say, an Oil fired power station - you'd likely be looking at a reasonable level local oil contamination, and probably a large fire. I don't know how much more likely that such an event would be to happen but I am going to guess that safety and fail safes at fossil fuel stations are not quite the same as at a nuclear plant :)

(in terms of your last point; it totally can. But practically speaking it is something that has to start at home. Millions of people can afford solar panels on their home; but they mostly don't bother (and some moan about the lack of action...!). And we could be pressuring local government to introduce housing regs requiring new builds to have solar panels.)


I never said it'd easy, or that it wouldn't cost money. Everything costs money. Nuclear power plants are expensive, and they have vast hidden costs that are offset to society (how much will it cost to Japan to clean up this mess? is this added to the cost?). Many countries are already getting a very significant percentage of their energy from renewable sources, things like solar power or wind power are getting more efficient by the day, and if a real, massive and sustained investment was done in this area I think we wouldn't be having debates like this one in 10 years. And I won't even enter to discuss topics like energy independence, which are huge.

Anyway, clearly a complicated issue, not trying to convince anyone here of anything.


I disagree as it happens, I think it is actually not all that hard to make a major impact without getting serious govt. funding (which sadly is like squeezing blood from a stone). All it requires is for those people with enough funds to go out and buy solar panels for their roofs.

Even my parents, who are not exactly the most well off people, can afford (and have bought) solar panels. It doesn't make them self sufficient - but if everyone in the town (that could) did it that is a massive impact!

We had a survey here recently - in the town of about 15,000 people only 48 had solar panels. The statistics from ONS for the area suggest that at least 20% of the residents could afford solar panels.

Just saying :P


"but if everyone in the town (that could) did it that is a massive impact!"

No, it is not: http://www.inference.phy.cam.ac.uk/withouthotair/c6/page_39....


I'm not entirely sure that is as negative as it sounds. My average consumption is about 4KW/h per day. I just checked with my parents and they, with a multi-computer a home office, use about 6KW/h per day. So lets take that as an average.

Our systems account for about 2KW/h per person, per day. So that is about 30% of our own energy consumption.

15,000 ppl @ 6KW/h = 90,000 KW/h

3,000 ppl (20%) generating 2KW/h = 6,000 KW/h

That's 6% of the towns energy generation.

Which might not sound a lot, true. But on the other hand commercial renewable energy production in the UK accounts for about the same amount (8 ish percent I believe). So if everyone did it that would double renewable energy production.

I find that significant :)

I admit to "over egging" the ease, and being extremely optimistic in terms of the coverage and uptake of such a mass social movement :) but I still think it is something we all should try.


Anything can be done but at what cost? Along with that willingness must also come the understanding that the standard of living for the majority of the planet's population will be lowered, probably dramatically in some places. Renewable energy, to this point, has been much more expensive than non-renewable energy and this has allowed the human species to enjoy a reasonably high standard of living, especially in the developed world. Now, the developing world wants part of that and telling them they have to use renewable energy seems rather disingenuous to me.

Renewable energy is entirely possible but it's a truly difficult problem, not just technologically but from a cost-benefit side as well.


What potentially devastating consequences would there be if an oil rig had been hit by an earthquake, tsunami and explosion? Also consider the size of an oil rig(s) that would need to provide the same amount of energy.

Similarly, what would the consequences be if a chemical plant producing say pesticides were to undergo the same fate? Simply because a process may be dangerous doesn't mean that it can't be safely harnessed into the service of man.


That one windmill won't provide near the power output of one nuclear reactor. It would be more like an entire windmill farm getting hit. Also, look at what happened to the coal plants; fires everywhere and explosions at the oil refineries. The nuclear plants look far safer to me. Don't try and use hydro as an example of safe power lest we forget what happened in China recently.


How much land needs to be paved over with windmills to equal the power output of one nuclear plant?


A handful of square meters per windmill, unless it's off shore and then it's none (as in no land). You realize windmills for energy production dots the Danish landscape, placed in handfuls in the middle of farms, right?


Yeah, but Denmark has a population of 5.5 million people and ample land for them and windmills.


It's not a technology problem, it's a people problem.

The technology works incredibly well. And in Japan, the people are well trained and prepared, and I have every confidence that they'll be able to cool the reactors down without releasing much radiation into the environment, as long as nothing else goes wrong.

Now take that exact same reactor and build it in Iran, Bangladesh, Congo, Libya. Do you have the same confidence in it? Japan was a best-case scenario.


That seems like an amazingly positive result to me.

the result might be not positive enough regarding the possible long-term damage it still can have to the environment and the japanese people (35M in tokyo area alone).


The threat of death's and longterm genetical damages for our childrens and their's and the loss of a huge terretory for thousand's of years isn't exactly an amazingly positive result to me. Who know's if the cancer of my mother and my father (both died young) was caused by the radiation we received from Tschernobyl in Europe. I think one has to actually live through the threat of radiation ( I did and I feel with the Japanese today) to understand why the Germans are shutting down their nuclear plants and why this is the only reasonable thing to do, once you realize that it is an arrogant error of mankind to think they can control nature.


I still remember the voices after Chernobyl: Light water reactors are safe and core meltdown can never happen, because the moderator is water. If it evaporates, the moderator is gone and the core will cool down.

Chernobyl was a graphite moderated reactor. When the core overheated, the graphite melted together with the uranium and the nuclear reaction could not be stopped any more.

Now we see how reliable those reports really are. There is no base for any beliefs, if you ask me.


Hmm, I think it is readily accepted and established that complete loss of coolant in a LWR will lead to meltdown - although I can't comment on whether that was the scientific opinion immediately after Chernobyl.

The problem at Chernobyl is not as you describe. The issue there was that through a process of bad core management, while trying to shut down the reactor and at the same time run an experiment, meant the core ended up in a very unstable state. Mostly the instability was managed automatically but at some point it went wrong; there is much debate over this, though conventionally it is accepted that someone, it is not known who, SCRAMmed the reactor - the poor design of the control rods meant that rather than immediately stop the reaction it actually made things worse as they were inserted, causing the core to overheat causing extreme pressure, cracking the control rods and essentially making the situation unrecoverable. Then a steam explosion broke the pressure seal and the chamber emptied of coolant.

After that the exact mechanics of what happened is somewhat unknown (instrument failure) but the lack of coolant lead to a critical "nuclear excursion"; i.e. essentially the neutron emission becomes so large that the fuel becomes supercritical. The excursion heated the fuel so that it expanded and "exploded" out of the pressure vessel; once that had happened the fuel was dispersed and the nuclear reaction ended.

At that point the graphite was exposed to the air and caught fire; it was this (and the resulting smoke plume) that spread most of the radiation.


I still remember the voices after Chernobyl: Light water reactors are safe and core meltdown can never happen, because the moderator is water. If it evaporates, the moderator is gone and the core will cool down.

You misunderstood. No one reasoned that loss of water coolant would somehow cool the reactor (that's self-evidently absurd); they reasoned, and still reason, that loss of coolant would shut off the fission reaction. This rules out, not meltdowns, but uncontrolled power excursions like the one that created the steam explosion that blew up Chernobyl.


"There is no base for any beliefs, if you ask me."

Yet I bet you go on eating food, in the belief it will keep you alive.


This is the wrong comparison. You can choose the food you eat, but you cannot choose the energy you use. At least not as easily. But there are similarities: the industry that sells energy wants to go on running their reactors. They advertise and we belief and consume.

There is also an industry (or industries) that tries to control the food market. We belief and consume. Now look at the rate of overweight people and tell me they do a good job.

As much as I like to get healthy (as good as possible) food I also want clean (as good as possible) energy. Japan shows again, that nuclear power is hard to control. And loss of control has devastating consequences.

This is not what the nuclear industry tells us, right? So it is not the right thing to believe. The same with the food industry, as you dug out this comparison.


I think he spoke of beliefs about nuclear safety.


uvdiv, I did not misunderstand.

The light water is the coolant AND the moderator. You need a moderator that slows down the emitted neutrons to keep the nuclear chain reaction going.

But evidently, the water is not the only moderator they use. They don't use graphite, though.


But evidently, the water is not the only moderator they use.

Where did you get that assumption from? Water is definitely the only moderator in this form of LWR (based on the published design specs).


I consulted Wikipedia about the design of german light water reactors. Bor is used in addition to water. It enables regulation of the power (in some limits). Makes sense to do that. I don't know if this is done in Japan too. It could explain, why the reaction does not stop after the water is gone.


Oh I see.

This is a Boiling Water Reactor, a variant of LWR's, it does not use Bor (in any form) as a day-to-day moderator.

However in this incident Boric acid is being added to the water to help with the process.

Pressurized Water Reactors use Boric acid, which is a different variant.


By voices you mean Soviet propaganda for not only a poorly designed plant but also a poorly designed plant run poorly.


No, I am talking about german news reports. It makes no sense for the soviets to say that light water reactors are safe after a graphite moderated system has gone out of control.

Chernobyl could never happen in germany, because the construction of light water reactors is inherently safe. Thats what the news reported and the politicians claimed.

Do you see what happens now? Something like in Japan can never happen, because we don't have earthquakes and Tsunamis like they have.

These reports are not reliable. The basic idea, that a reactor has to shut down, if it gets out of control, is the right one. But it seems, the idea is not implemented well enough, even in the light water reactors.


The question is what exactly you expected of it. You've taken one of the oldest and least intrinsically safe designs since chernobyl (at least compared to anything recent like a nice pebble bed/molten salt reactor), hit it with an earthquake, washed it away with a tsunami and blown it up with hydrogen gas explosions.

And it's basically just that there, leaking a fairly small amount of radiation. Compare that to other objects that could cause environmental damage, like say an oil tanker or a chemical plant and try and compare it in similar circumstances.

If you were to take say a standard pesticide factory, hit it with an earthquake, followed by a tsunami, followed by multiple explosions, I would be very surprised if it could keep the same level of containment of its material.

To give you an example of what happens when a major chemical plant breaches, have a look at the Bhopal disaster. It isn't unreasonable to say that a major chemical breach is on the same scale as a small nuclear incident and as such I would consider the comparative reliability of nuclear plants to be rather remarkable and a testament to the engineering that goes into building them.

Also interesting to note is how things have progressed. Remember that this reactor was built in 1971. If you look at a newer design, such as a pebble bed reactor you would notice that it exhibits passive safety, ie. that if you were to subject it to the kind of failures that have befallen the fukushima plant, it would simply fail safe until it could be fixed. Even in the event of a catastrophic failure of the reactor core, very little radiation would be emitted as the core itself is encased as a series of nearly indestructible silicon carbide pellets, and the preferred coolant very rarely absorbs neutrons. This would also mean that coolant leaks would be a lot less of a concern environmentally as the coolant would not be as radioactive.

[1] http://en.wikipedia.org/wiki/Bhopal_disaster [2] http://en.wikipedia.org/wiki/Pebble_bed_reactor


If one of the worst earthquakes on record can't break the containment vessel in these old plants, then I think we're actually doing very well.


it is not clear at this moment if the containment vessel is damaged or not. the spike in radiation levels that was measured lately does indicate that it is broken.

Edit: If you want to read up on the radiation levels: http://www.stratfor.com/analysis/20110315-red-alert-radiatio...


The news ticker at heute.de was pretty sure about it, saying there are two holes each eight square meters in size in reactor 4. Of course I can't say how much truth lies in that statement.


The Brazillian news was claiming that a huge nuclear fallout cloud was heading their way and that everyone should stock up on iodine. The Austrian news was claiming that the meltdown was fully under way and that hell on earth was about to be unleashed.

I'd wait until we have clear news about what's going on before making an opinion.


That's talking about the reactor building (i.e. the outer walls). It's not 100% clear but they were at one point demolishing those walls to help vent hydrogen from the building. But I saw anbother source saying an explosion in that building caused the holes.

(Unit 4, BTW, is shut down & stable, but it is the building with the fire in the spent fuel pond)


AFAIK the radiations might come from the fire in rector 4.


... Which would mean an explosion damaged the containment vessel. The earthquake did remarkably little damage to the plant.


You do realize that everything that has happened at the plant since the earthquake, including that explosion, is a direct result of the earthquake, right? That's like saying the airliners didn't take down the World Trade Center, the fire did. There wouldn't have been a fire if it weren't for the airliners.

The earthquake and subsequent effects of the earthquake destroyed these reactors. It's a pointless distinction to say otherwise, designed to soften the blow to nuclear power's reputation.


Of course, but I find your analogy quite poor. All I meant was that the plant [apparently] suffered no damage from the earthquake (which was quite a bit stronger than it had been designed to withstand). It was the tsunami--also larger than the sea wall was designed to withstand--knocking out power that got the plant into its current state. A cache of compatible backup generators that were kept high enough or remotely enough could have prevented this disaster.


Assuming the conservative base in Germany wouldn't back Nuclear Energy. I don't know what it's worth but this wouldn't be true in France for example.

As for reconsidering Nucealr Energy, I still think we should wait for the end of the whole thing. Indeed I realize this won't happen.


It‘s not so much about the conservative base. The CDU can be relatively sure that their base will vote for them regardless. Opposition to nuclear energy is a popular position in Germany, also in the political center. This decision is supposed to appease those voters.


Nice to know that there is another country out there that's as irrational as the US.

Does Germany have a lot of tsunamis?


Only in public opinion. Did you read the bit about Merkel getting thrashed in regional elections?


No, but earthquakes. And we are so clever to build nuclear plants on places where they are more likely to occur.

http://en.wikipedia.org/wiki/M%C3%BClheim-K%C3%A4rlich_Nucle...


This is more likely just a publicity stunt to calm down the people, since there are elections coming in several federal states and the reigning party CDU already lost a lot of ground. I would be surprised if anything really changes


Does it need a Tsunami to have the cooling system of a nuclear power station to fail?

How about: an accident with an aircraft (Germany has lots of air traffic), an earth quake (yes, Germany has earth quakes), sabotage , operator errors (happens sometimes, see Three Mile Island, Chernobyl, ...), terrorist attacks (Germany is a terror target due to its participation in the Afghan war), military attacks, random technical failures, ...

The nuclear power station next to me in Krümmel is shutdown because of technical failures and general total incompetency.


how come that so many HN readers are so pro-nuclear? would that change if the fall-out from japan would hit the U.S. like the chernobyl fall-out hit germany in the 80s?


My fellow Germans are sometimes a funny people. Apparently the sales for iodine pills skyrocketed this week.


This decision is not so much irrational rather than populistic: There are several upcoming elections this year.

IMHO, this is the best explanation for the sudden change of heart of those who decided to prolong the duration of the atomic reactors just a few months ago.


Naww, but soon they'll have more people with lung cancer from breathing all that burning coal and oil for energy.

I think this is a political move that is going to help in the next election. The "greens" will see this as a handout to them and nuclear power is too complex and scary an issue to have someone defend it properly. Oh well, back to fossil fuels!


the situation is a little bit more complex in Germany: after the former government negotiated the nuclear power exit with the four big power companies maintaining nuclear power stations, these big four were able to adapt their strategy for the days after, which they did. so especially the concession made by the current government about letting the old power plants run longer than planned is considered to be just a huge gift to these companies by a lot of germans (unexpected bonanza for the companies).


Did the US shut down any of its nuclear reactors, if they did, I certainly haven't heard about it


About as many as we have earthquakes.


I guess a knee-jerk reaction can be expected in a country where nuclear power is currently pretty controversial.


Think of a needle on a gauge representing public opinion about nuclear power. One half of the gauge reads green for nukes. The other half is red for no nukes.

If the needle is firmly in the green, a slight shift towards red in response to Fukushima might mean commissioning some studies and announcing a budget for upgrading the safety features.

But if the needle is just barely into the green, a slight shift moves it into the red and that means shutting them down. So yes, in a country where public opinion is divided, it is not out of the question to swing from yes to no in response to the biggest emergency since Chernobyl. I'm not sure about the phrase "knee-jerk," though. It may seem like a drastic move, like a leg kicking in response to a small tap, which implies a response out of [proportion to the stimulus.

However, perhaps the response is in proportion, it's just that when the needle is right on the dividing line, it only takes a small move to get from green to red?

Now that I write my thoughts out, I obviously agree with you :-)


"Biggest (nuclear) emergency since Chernobyl" seems hyperbolic unless the situation has changed considerably since I last looked at it. Indeed in Japan alone the Mihama Nuclear Power Plant accident in 2004 caused more fatalities than Fukushima has so far.


According to Wikipedia, the 2004 incident involved people being killed by a broken steam pipe. That's an emergency that happens to have been at a nuclear plant, not a nuclear emergency, and the regional effects were zero.


I don't think this is a knee jerk reaction. I think this is a move for short term political gains without regard for the long term societal costs.

They had decided to extend the life of the reactors just last year. No new risk inherent to their design has been exposed. No new tsunami or earthquake risk in Germany has been exposed.

I agree with the person quote in TFA (despite the fact that his statement may be a political play as well) :

"She just wants to get through the provincial assembly elections," said Social Democrat leader Sigmar Gabriel, accusing her of playing political tactics with people's fears.


Note that Sigmar Gabriel wants to shut down all nuclear reactors himself.


Here is a link to an article from his official web page where he appears to be stating a generally anti-nuclear point of view

http://www.sigmar-gabriel.de/Nachrichten/details/20110313_at...

This gives his statement about Merkel's move just being politics more weight


It's only a temporary measure anyway, the plants will be inspected and (if everything well) turned on again until 2023 or so.

Personally, I'd feel a lot safer if all nuclear plants were turned off forever. Sure, the chance of something going horribly wrong is low, but if it goes wrong it is a big big mess. Just too horrible to warrant any of the advantages that nuclear power has.


I feel almost infinitely more threatened by a lack of electric power than a nuclear plant accident (the nearest one is about 35 km from here, for the record). And that is much more likely to happen; from some perspective, it even seems inevitable.


The deaths from other fuel sources, while not as immediately obvious as "oh look that nuclear plant just blew up" are potentially far greater.


Frankly, I have heard that argument many times. I know other fuel sources cause deaths too. Gas tanks can explode, fossil fuels exhaust gasses can be poisonous, oil can leak into the sea, and so on.

And still I'd rather be exposed to all of those risks than worry about one nuclear explosion. As I said, the consequences can be just too horrible, for too many people.

I'd love to move on from fossil fuels to something else, but not something that can cause such disasters.


Any production of electricity is going to result in deaths. It is simply the nature of the immense scale modern society operates on. Coal power plants release pollutants that shorten the lives of tens of thousands of people a year. Coal mining kills thousands and devastates environments. Have you seen the picture of mountains that were leveled for coal in West Virginia?

Most of the mercury in fish originates from coal-burning power plants. [1]

Do you fly? A single airliner accident can kill hundreds at a time, but cars kill many more people a year. Somehow it's more acceptable for people to die one or two at a time in great numbers.

[1] https://secure.wikimedia.org/wikipedia/en/wiki/Mercury_in_fi...


That's because you're mind is clouded by the effects of a mental fallacy (the availability heuristic to be precise) http://en.wikipedia.org/wiki/Availability_heuristic


You have the full right to disagree with me; I voiced my post as my personal opinion. But you're very rude to say my mind is clouded. I simply don't like large downside risks.


Huh, I cannot react to your post directly.

No matter how you compute statistics, a nuclear meltdown is a big downside risk. It can happen, and if it happens it's extremely destructive. It's an event with a small chance of occurence but with great consequences.

That's qualitatively different from something like traffic accidents. The chances of those happening are much higher, but if they happen, they affect at most a few people, They won't turn your city into a 'wildlife reserve' for years to come.

Even though the total amount of people that die of traffic accidents is higher, to me it's less scary. The risks are more manageable: you have some degree of control over it (drive safely) and the consequences are visible.


It's not a personal attack and now you're using a strawman argument to deflect my response (I'm not saying you don't have a right to voice a personal opinion, simply that you aren't looking at this objectively). If you read the link I posted you'll see that what you think is a "large downside risk" only seems that way because of a perception fallacy - we believe incidents like nuclear explosions and airplane crashes are much riskier than everyday risks like lung cancer deaths and car accidents.


Germany's green party has been trying to kill the nukes there fore quite some time now: the SPD/Greens officially announced their desire to phase out all nuclear power in Germany in 2000, and two power plants had been shut down in 2003 and 2005 and were planned for dismantling.

The CDU (Merkel's party) was an opponent to the phase-out, and has been very open about it since 2008, but I'm guessing they saw the writing on the wall: the Fukushima events can only fuel the already powerful german anti-nuclear movement (we're talking rallies of tens of thousands in recent years) further and there's no point in wasting political capital on a lost battle.


The phase out seems to have become political consensus during the last years, there is only disagreement about the time table.


Context: The previous government had decided to phase out nuclear power by 2020. After the last election the current revoked that decision and even allowed old power plants that were due to be shut down to operate longer. So, if they hadn't revoked that decision, the seven reactors we are talking about her would have been shut down already or would be about to be shut down anyway.


I don’t think all those seven nuclear power plants would already have been shut down – more like three or so.

I listened to the press conference this morning and it sounded like their decision to shut down all seven pre-1980 plants had something to do with the relevant law. This law makes a distinction between pre-1980 and post-1980 plants which can be used to justify their decision.

If the government wants to shut down power plants they obviously need some basis in law to do just that. There seems to be a section in the relevant law that allows them to shut down nuclear power plants but arbitrarily shutting them down is not possible. (At least if the government doesn’t want to pay damages to the operators.)

The government probably is worried that a decision to arbitrarily only shut down certain pre-1980 nuclear power plants without a good reason for the distinction would run counter to the principle of equality.


You're right, that's what I meant to say with "or would be about to be shut down". Three of the seven would have been shut down this year, another one in 2012 and the final three in 2013 (source: http://de.wikipedia.org/wiki/Liste_der_Kernreaktoren_in_Deut...). Last year it was decided to extend the lifetime of these reactors to 2019 or 2020.


What are they replacing nuclear power with? From what I understand, Germany is one of the few countries ramping up manufacturing, which is a huge consumer of power. It's interesting that they are essentially cutting supply as demand increases.


Fossil fuels and energy imports (short term) and renewable energy (long term).

In 2010, 16 percent of all electric power in Germany came from renewable sources (6.4 percent wind, 4.2 percent bio mass, 3.2 percent water, 1 percent photovoltaics, 0.8 percent waste). Coal is at 43 percent, nuclear energy is at 23 percent, oil and natural gas are at 15 percent. (Source: http://www.bmwi.de/BMWi/Navigation/Energie/Statistik-und-Pro...)

The current government thinks that ramping up renewable energy to replace nuclear energy until 2030 is realistic.


The official plan is to have it replaced completely with renewable energy technologies by 2020.


They are not permanently shut down. This is most likely a move because of the impending elections, as nuclear energy is quite controversial here in Germany.


The events in Japan represent the end of nuclear energy as a viable long-term option.


"Long-term" is a long time. The next few years? Maybe. The next hundred? Of course not.


http://www.theregister.co.uk/2011/03/14/fukushiima_analysis/... has a fairly sober analysis that shows just the safeguards are generally working even in a scenario not even imagined.

(Yes, yes, one has to imagine all possibilities, but all human life involves some risk.)


The real lesson here is that you've got to evaluate options on the basis of what happens when the system fails.

Because the system WILL fail.

This is one of the hardest lessons for engineers to learn. That you simply cannot prevent failure. You can make it less common. You can take all reasonable steps to prepare against it. But failure will happen.

So what are the consequences when it does?

The answer in the case of nuclear power is that the cost comes at a level and in a form that many societies are not willing to pay. You can argue the irrationality of that, but you'll lose the argument. Societies don't make decisions on a rational basis. And they're never going to.

This incident is in fact a failure of engineering. There was radioactive material released into the atmosphere in an uncontrolled manner. It doesn't matter if it gets worse or better, that's the thing that absolutely was not supposed to happen. It did. The system failed.


Since when was Germany in a major seismic zone? Political grandstanding I fear.



This move will push renewable energy know how in germany.


Fukushima. It's Fukushima.


Stunt.




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