Japanese Earthquake

[WhiteBlue]

I just want to remember our ex moderator Ciro about his position on nuclear a year ago and my answer to that.

viewtopic.php?p=166170#p166170

As nuclear energy does not produce global warming gases, it is better for the environment (I mean, for me and you). We already discussed this theme and it seemed to me that after reviewing the figures, the forum agreed that the way to go is nuclear.

Of cause Nuclear energy produces no global warming gases, but that doesn't mean at all that the production of nuclear energy, the handling of nuclear fuel and the associated waste is good for the environment...

There are examples of nuclear reactor accidents caused simply by their building collapsing from material fatigue. The more we have to be concerned that far more dangerous reactors like the sodium cooled fast breeders can be hit by aircraft terrorist attacks, earth quakes or even plain stupidity in civil wars.

Countries with the social stability of Iran are building reactors and who knows what dumb sh!t in possession of a tank or howitzer may decide to blast some holes in a nuclear facility? California, Japan and a bunch of other states with active volcanoes and regular earth quakes are building reactors happily without a thought of the wider consequences...

Today's operating reactors are mainly big water cookers with temperatures of 200-300 °C and based on technology that is fairly well understood. Nevertheless these rather simple plants can be effed up as Chernobyl shows. The future reactors will mainly be breeders with design technologies that are unproven or undeveloped and on temperature levels of 800 °C. The coolant will not be water that carries limited contamination and destructive potential but liquid sodium that ignites in contact with air and water and can easily blow up a nuclear core in a case of ignition. All prototype breeders with sodium cooling have had coolant leaks (due to high temp corrosion) and some even coolant fires. One dumb guy with a rocket propelled grenade can blow up the secondary sodium circuit which isn't usually protected by the containment and the whole plant including the core goes up in the air. Future breeders will use some 6000 tons of liquid sodium. I leave it to someone else to figure the equivalent of TNT but I tell you we are not talking fire crackers here. A breeder reactor can go critical if the grid power is lost for some reason for half an hour and the back up generators do not kick in. The reactor relies on the big sodium pumps running to circulate thousands of tons of liquid metal through the heat exchange circuits. .

As we have seen it is sufficient that the infra structure around a power plant is destroyed by a catastrophe and the decay heat will destroy most reactors due to lack of cooling. Whether the destruction comes from military weapons, natural disaster, terrorist attack or aircraft accidents doesn't matter in my view.

This accident series in Japan simply demonstrates that it is almost impossible to protect against all configurations of disasters that can impact on this inherently dangerous technology. My opinion remains the same. Get rid of the nukes and particularly the breeders.

[Pup]

WB, you make a good argument against the use of this particular type of reactor, and I agree with you. But at some point you have to admit that there are reactor designs which to not require active cooling/backups. You may have arguments against those as well, which I'd like to hear, but you can't use an argument specific to one type of reactor or group of reactors as an argument against nuclear energy as a whole, because it just doesn't make sense.

BTW, I ran across this very good "everyman's" explanation of the event here...

https://morgsatlarge.wordpress.com/2011 ... -reactors/

I strongly suggest everyone read it before posting. It's great to have debate, but as this is a technical forum, it might be in our interest to have an informed debate.

[Dragonfly]

Read with great interest, Pup. Thank you.
For a fact I didn't know the logarithmic nature of the Richter scale. 7 times more powerful earthquake than expected, that's astonishing.

[gridwalker]

Pup, you should read about the "pebble bed" reactor : http://en.wikipedia.org/wiki/Pebble_bed_reactor

Pebble bed reactors have the following benefits :
* passive safety
* inert gas cooling with no phase transitions
* automatic shutdown under critical conditions (thermal limiting feedback loop)
* simplified design
* no requirement for active cooling systems

This reactor design is impervious to the kind of disaster that is unfolding in Japan.

I first discovered the pebble bed design in New Scientist nearly 10 years ago, but it has been starved of funding due to anti-nuclear sentiment. If this reactor design had reached commercial viablitiy then the whole industry would be an order of magnitude safer than it is today.

[marcush.]

the one thing i find striking in these events is the fact that events from the outside are detected but the reaction of the system will not put the whole station into a safe state for sure....lots of safety systems but al need aditional intervenation to control the situation -so basically they are designed to buy more time,instead of shutting the whole thing down into a safe state as quickly as possible.

[marekk]

Read with great interest, Pup. Thank you.
For a fact I didn't know the logarithmic nature of the Richter scale. 7 times more powerful earthquake than expected, that's astonishing.

Actualy, richter's scale is logarithmic with base 10 for amplitude, but as for energy dissipated, one degree is about 32 times more energy. So 8.9 is about 22 times more then 8.2.
That's even more astonishing.

[Pup]

the one thing i find striking in these events is the fact that events from the outside are detected but the reaction of the system will not put the whole station into a safe state for sure....lots of safety systems but al need aditional intervenation to control the situation -so basically they are designed to buy more time,instead of shutting the whole thing down into a safe state as quickly as possible.

Well, the initial reaction was shut off immediately. But there are particles that are produced in the initial reaction that also decay, over time, creating more heat. So even though you've flipped the switch so to speak, there are still a few days of having to keep cooling the core so that the temps don't rise to critical level.

[WhiteBlue]

Pup, you should read about the "pebble bed" reactor : http://en.wikipedia.org/wiki/Pebble_bed_reactor

Pebble bed reactors have the following benefits :
* passive safety
* inert gas cooling with no phase transitions
* automatic shutdown under critical conditions (thermal limiting feedback loop)
* simplified design
* no requirement for active cooling systems

This reactor design is impervious to the kind of disaster that is unfolding in Japan.

I first discovered the pebble bed design in New Scientist nearly 10 years ago, but it has been starved of funding due to anti-nuclear sentiment. If this reactor design had reached commercial viablitiy then the whole industry would be an order of magnitude safer than it is today.

One needs to read no further than the quoted Wikipedia article to find that the development of the pebble bed reactors (in Germany) was fraught with its own particular problems. The failure mechanisms are different which doesn't mean that the risks are necessarily smaller.

Temperature control of the reactor is significantly more complicated and the pebbles can crack and develop dust by abrasion. The particular matter which circulates through the turbines will contain Strontium which is a dangerous particle beta radiator. A plumbing problem in the turbine circuit or a turbine casing failure can potentially create higher risks than a breach of the reactor vessel of a boiling water reactor. The German reactor developed a crack in the bottom of the reactor vessel which contaminated the soil and ground water under the reactor. The clean up will cost more than € 1 billion. There are no known methods of de commissioning and cleaning up a failed or used reactor of commercial scale.

I'm pointing that out to balance the myth that there are nuclear reactors that are fail safe and without problems. That is a lie which is easily debunked by the history of the 30 years of development of pebble reactors. It may be possible to develop this type of reactors to a commercial size on the same safety level of the modern water reactors but this project is far in the future and currently just on paper. The next generation of pebble reactors will have their own safety problems. I'm very confident of that. One look into the history of reactor development will quickly make that obvious to everybody.

[Pup]

Pup, you should read about the "pebble bed" reactor : http://en.wikipedia.org/wiki/Pebble_bed_reactor

Pebble bed reactors have the following benefits :
* passive safety
* inert gas cooling with no phase transitions
* automatic shutdown under critical conditions (thermal limiting feedback loop)
* simplified design
* no requirement for active cooling systems

This reactor design is impervious to the kind of disaster that is unfolding in Japan.

I first discovered the pebble bed design in New Scientist nearly 10 years ago, but it has been starved of funding due to anti-nuclear sentiment. If this reactor design had reached commercial viablitiy then the whole industry would be an order of magnitude safer than it is today.

Yes, though these do have their own problems, and seem, from my layman's standpoint at least, to be awfully complex. That's why I prefer the MSR design - it seems to be much simpler and has all the advantages of the pebble bed reactor without the drawbacks.

[Shrieker]

https://morgsatlarge.wordpress.com/2011 ... -reactors/

Pup thanks for sharing, it was a good read. But 200.000 (and maybe more to come) evacuees speaks volumes, don't you think ? Surely, if the risk was so low as mentioned in the article, they wouldn't have bothered move 200.000 people.

http://www.channel4.com/news/japan-how- ... ear-blasts

And more problems elsewhere...

[manchild]

These guys knew what happened as soon as it did, and what would follow.

10 Germans flee Japan's quake-hit nuclear plant

Published: 13 Mar 11 11:13 CET

Online: http://www.thelocal.de/national/20110313-33685.html

Ten German employees of nuclear giant Areva were conducting maintenance work at Japan's Fukushima plant during Friday's massive earthquake, according to a Sunday report. A company spokesman said the men immediately left the site.

The technicians were working in a building housing reactor 4, which had already been shut off before the quake hit, Bild am Sonntag reported. A massive explosion occurred around reactor 1, increasing the risk of a nuclear meltdown and radiation leaks.

"They left the power plant immediately after the earthquake and fled further inland," Areva spokesman Mathias Schuch told the paper. "All 10 are healthy and doing fine."

Schuch said the company is in communication with the men through business partners in Japan and added that employees' relatives have been contacted. Areva has requested help from the Federal Foreign Office in procuring a plane to fly the men home.

"We are doing everything in our power to work together with the embassy and the Federal Foreign Office to bring all employees home to their families in Germany as soon as possible."

Foreign Minister Guido Westerwelle has called on all German nationals in regions affected by the catastrophe in Japan to leave. He said about 100 Germans live in those areas, with some 5,000 total located across Japan.

Westerwelle noted there had been no indications that Germans were hurt due to Friday's earthquake and subsequent tsunami.

Meanwhile, a German aid team from the Federal Agency for Technical Relief (THW) arrived in Japan early Sunday morning. The aircraft with 38 workers, three search dogs and 12 tonnes of equipment on board left Frankfurt's Hahn Airport Saturday afternoon.

The plane's departure was delayed by nearly one hour in order to obtain dosimeters to measure radiation exposure, following the explosion at Japan's Fukushima nuclear plant.

The team will mostly aid efforts to locate and rescue survivors buried beneath the rubble of collapsed buildings. THW president Albrecht Broemme said the team would not be sent to work in areas affected by potential radiation leaks.

DAPD/The Local/arp

[Richard]

I suggest people read about Three Mile Island, it is very similar to this incident - ie failed coolant circulaton.

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

[forty-two]

I am in a state of shock at the moment, firstly because of the terrible loss of life and disasters in Japan resulting in massive loss of life, a looming humanitarian disaster and lord knows how much infrastructural damage which will inevitably result in the further suffering of the people, coupled with the nuclear incident which will arguably have ongoing health ramifications for the people, but perhaps only a notch or ten down the scale (note the scale is logarithmic in my own personal case), I find myself agreeing with WhiteBlue, wholeheartedly.

Nuclear installations are, under perfect conditions dangerous. Building one on "shaky ground" as it were, strikes me as a seriously bad idea as has been proven by the recent events in Japan. I fear that more such incidents, or a further problem caused by an apparently similar problem at unit 3 in Fukushima which is using "experimental" fuel rods which include both Uranium and Plutonium, and at another site apparently not too far away. All of which are cooling related.

I for one work very close to a nuclear weapons manufacure facility, which hopefully will ensure my instantaneous vapourisation in the event of a serious incident which IMHO is miles better than suffering a nuclear winter. This is something I have given considerable thought to.

No sensationalism required here, the events playing themselves out here are quite scary enough without adding anything to them.

[manchild]

Another reactor unit exploded. Repeated situation - Hydrogen explosion, evacuation...

http://www.independent.ie/breaking-news ... 78116.html

This is marking the new era in our civilization. Regardless on how severe it ends with these power plants, Japan at first and the most democratic countries to follow will be forced by people to change the whole philosophy of economy, since electric energy is what it makes it running. Friday marked the first day of retirement of the nukes. Perhaps now there's a chance for really clean technologies and fuels to see the light of day after being hidden in bottom drawers of institutions controlled by oil and nuclear corporations.

[Agenda_Is_Incorrect]

So, now the only thing missing to go completely off topic is done. But obviously manchild has the best of the intentions in doing it, as he is not a corporation or anything evil or politic. He's a humanist trying to enlighten us with no politics or hidden interests at all, nor he is doing anything wrong in the hope millions of people die or downgrade their lives to poorness levels so that we can get rid of those annoying nuclear plants. They are our only "zero carbon" source of power so far and obviously they are a threat to doom sellers.

I'm guessing locking or editing will be needed again. This topic should be about the Japan earthquake and it's more immediate issues. Other issues and other crap should be at off-topic if even allowed to be in this forum.