Japan hit by 9.0 earthquake.

[Jadzia]

Re: Japan hit by 8.9 earthquake.

6.1 quake off Tonga...

The whole Pacific rim must be having a shift session. With Christchurch in Feb, Papau New Guinea not too long ago, China last week and now Japan and Tonga.

I'm hoping the Cascadia fault line doesn't join the party.

I'd be concerned if I lived there. The Japanese quake is said to have shifted the earth's axis by 25cm. That's a sudden change in angular momentum of the plates (think gyroscopes). So imagine the torsion that shift will have created. I wouldn't be too surprised if we saw bits of shocks spreading across the whole ring of fire.

It's not over yet. We had another 6.8 aftershock about two hours ago, and there have been well over 100 aftershocks since the big one yesterday. And yesterday shortly before the 8.9 quake I saw the crescent moon above, barely noticeable but with its significant tidal pull on those fault lines, and of course it's up there now almost in the position it was at the time of the big one yesterday.

I've often wondered what role the moon plays in earthquakes. Tidal effects would keep all of the forces flexing, but I don't know how significant the effects would be.

 

[bigdaddy]

Re: Japan hit by 8.9 earthquake.

A few days ago I read about the super full moon that will happen on the 18th I think it said. There is no proof the moon screws with earthquakes and such, however fringe scientist believe it does.

I like this quote from a professor...

"Even in the worst-case scenario, that would mean some radioactive leakage and equipment damage, but not an explosion. If venting is done carefully, there will be little leakage. Certainly not beyond the 3-km (1.8-mile) radius."

 

[Ar-Pharazon]

Re: Japan hit by 8.9 earthquake.

There was a legitimate astro-physicist on CNN last night. He debunked any idea of cosmic effects in this.

Even so, the moon is still at a fairly far away point in it's orbit right now.

This is really the Earth doing itself damage right now.

 

[watermelony2k]

Re: Japan hit by 8.9 earthquake.

On a more optimistic note, look at how well-designed the skyscrapers are in Tokyo and how they coped with the earthquake. The swaying acts like a shock absorber.

http://www.youtube.com/watch?v=JhJzdtzl6KY

 

[TEACAKE'S PLEATHER DOME]

Re: Japan hit by 8.9 earthquake.

There has been a big explosion in one of the power plants and 45,000 people or more are evacuated 20k out of the area.

http://edition.cnn.com/2011/WORLD/asiapcf/03/12/japan.nuclear/index.html?hpt=T1

 

[watermelony2k]

Re: Japan hit by 8.9 earthquake.

Here's a dude who was on the observation deck of the Tokyo Tower. Note the swaying action.

http://www.youtube.com/watch?v=gwAeNxLW1Ew

We live in an unprecedented age of information in which whenever something big happens in the world, eyewitnesses can document and share their footage with the rest of the world within the same day if not minutes of the event happening.

 

[Holdfast]

Re: Japan hit by 8.9 earthquake.

Shockingly powerful earthquake, by all accounts. I was busy most of yesterday with one thing or another, so only really caught up on the details of the news today. Some friends of friends are currently in Tokyo, and as of last night, those who know them better than I hadn't heard back yet, but I'm sure they're fine as Tokyo doesn't seem to have been as hard hit in terms of damage. Japan is probably the most prepared country in terms of earthquakes, and they're now seeing the benefits of that preparedness. It's going to be a long time before the full impact in clear, both in terms of financial cost and life lost, though.

I'm relieved to hear that the consensus so far is that it doesn't seem as though the nuclear plants are leaking much despite the unbelievable magnitude of the quake, and the subsequent explosions. If this holds, it's really is a massive testament to the safety precautions now employed by in modern plants. If they can withstand something like this, I certainly have no fears about the plans to increase nuclear use in my geologically calm part of the world.

 

[bigdaddy]

Re: Japan hit by 8.9 earthquake.

What do you mean the nuclear plants aren't leaking?! They are going to give out iodine and you can't drink the water.

 

[Jadzia]

Re: Japan hit by 8.9 earthquake.

Perhaps Holdfast means not leaking fuel, as with an exposed core.

 

[Holdfast]

Re: Japan hit by 8.9 earthquake.

I said "much". Big difference between the minor leaking going on now and what would happen if the steel container surrounding the reactor blew open.

(edit: Jadzia got there first)

 

[bigdaddy]

Re: Japan hit by 8.9 earthquake.

You can get the amount of radiation in an hour that you are supposed to get in a year. Much is a relative term.

 

[Holdfast]

Re: Japan hit by 8.9 earthquake.

You can get the amount of radiation in an hour that you are supposed to get in a year. Much is a relative term.

I'm not saying it's all flowers and sunshine, but considering the alternative, and the sheer magnitude of the quake, it really is remarkable and extremely reassuring that it's been contained to the extent it has.

Strategically speaking, it also, in my opinion, makes the planned upcoming construction of new nuclear sites in the UK a much easier sell if the radiation leak is pretty minor, as opposed to the wider public dismay that be entailed by a full-blown core exposure. Since I happen to think that such nuclear expansion is going to be necessary to both keep the lights on, and meet our obligations under various climate treaties (at least until we develop fusion), I have double reason to be grateful for the containment largely holding.

Fingers crossed it remains so, both for the Japanese and the future of stable energy generation (which in the long-run, affects the quality of many more lives than even are currently affected by the earthquake).

 

[Shoehorn]

Re: Japan hit by 8.9 earthquake.

Based on what we are seeing here this is the more likely scenario:

(keep in mind this is a Boiling Water Reactor (BWR)-type plant. PWR plants CANDU reactors and british AGRs operate differently)

The reactor automatically shut down during the quake as designed. Loss of offsite power prevented the "core spray" and "flood fill" systems from operating as designed.

By carefully managing the reactor pressure and venting off small amounts of steam they would be able to keep the water level above the top of the core.

However without the backup power systems there is/was no way to bring fresh cool borated water to the core.

We're talking maybe a matter of six to 14 hours to core damage... possibly far less depending on the condition of the core. A fresh core would have less decay heat from secondary reactions where as a core in operation for 10 months or more would have much more decay heat.

So assuming the core is now uncovered... a chemical reaction takes place between the cladding of the fuel rods and the steam in the reactor. This liberates hydrogen and pressurizes the reactor.

Normally they'd vent the hydrogen into the suppression chamber below the reactor along with steam and a spray system would keep the whole thing from blowing up.

What most likely happened is the hydrogen built up and escaped from the suppression chamber and collected at the top of the reactor building... and ignited. That's more than likely what we saw in the video.

BWR MK 1 and 2 plants are housed in a "drywell containment" with a "reactor building" around that. So long as the drywell is not breached they have containment of the vast majority of the radioactive materials.

HOWEVER the reactor building does house the control units rod drivers motor-generator sets and support system piping. Damage to those units would make a bad situation worse.


---

Now in order of decreasing likelyhood.... the explosion could have been an attempt to operate a backup feedwater pump. Some early US plants had a turbine driven feedwater pump powered by a chemical reaction... more or less mix two really nasty chemicals together and spin the pump with the force of the explosion. They proved to be rather... nasty and prone to degradation because they were never used in operation.

The third and most unlikely situation would be a cold-water accident. This happens when you pour cold water into a reactor. Cold water causes the reaction to rapidly restart and increase in power causing a "power excursion"... technobabble for a run-away reaction/explosion. You get a low-level nuclear explosion (sub-kiloton) and a massive steam explosion. In otherwords: Chernobyl-scale damage.

Just not seeing that from the video footage. My educated guess is a hydrogen explosion in the upper stories of the reactor building.

 

[Holdfast]

Re: Japan hit by 8.9 earthquake.

Fascinating and extraordinarily helpful to have some clearly experienced input! Thank you for reg'ing and posting.

 

[Saul]

Re: Japan hit by 8.9 earthquake.

Was in Tokyo to feel the quake. Not nice. Crazy to see and experience.
It's a big one. But not "the" big one they are expecting.

 

[Goji]

Re: Japan hit by 8.9 earthquake.

My parents are panicking about this nuclear power plant thing and want me out of the country NOW. I am scheduled to go home in three weeks and my work contract goes for another two, and it is annoying hearing them talk like I'm going to come home a glowing radioactive mutant unless I'm on a plane tomorrow.

 

[AJBryant]

Re: Japan hit by 8.9 earthquake.

it is annoying hearing them talk like I'm going to come home a glowing radioactive mutant unless I'm on a plane tomorrow.

Dude, your avatar totally sells that post.

Still haven't heard from some friends in the Sendai area, and I'm starting to really worry about that.

 

[Kail]

Re: Japan hit by 8.9 earthquake.

Glad you are Ok Goji. I have not been able to contact Masao though.

 

[RJDiogenes]

Re: Japan hit by 8.9 earthquake.

^^ I hope you guys hear from your people soon.

Goji, you have our complete support in becoming a glowing radioactive mutant.

 

[Shoehorn]

Re: Japan hit by 8.9 earthquake.

Fascinating and extraordinarily helpful to have some clearly experienced input! Thank you for reg'ing and posting.

There is a nuclear plant near I live. Being a fireman I was given basic Nuclear Emergency Response training and later took more advanced training as it was offered. I am one of 4 people in the tri-county area authorized to enter the containment structure to perform man-down rescues. The plant has it's own team but they have to have a backup team in place... that's us.

On top of that I also took the Media Relations training when it was offered. They trained us to answer any questions that the media might ask and more importantly direct people to sources of information.

Then I have a father and two uncles who have worked in the nuclear industry... and they were Nuclear Navy before that... my mother worked at this plant as Health-Physics lab-worker until she had us kids.

...This kind of stuff is/was topical conversation around our table. I may not be a nuclear-engineer or even work there but I have learned enough over the last decade and a half to help alleviate some of the mystery and fear about these power plants.