Possible reactor meltdown in Japan

[Bluestream]

Originally Posted By: demarpaint
No one figured an earth quake of this magnitude, and there lies the major problem. I think the situation is worse than they are saying.


That's an understatement!.

Japanese PM had to hear about the last explosion when he was watching TV. Whatever you are hearing about this, multiply that by 4 times and you likely have the truth.


If you build Nuke plants, on one of the largest geological fault lines in the world, do you think there might be a problem some day??? Also, it was built for the quake, but the Tsunami caused most of the damage, as it was not designed for tsunami. Diesel generators were flooded as they sat low in the building. I learned in grade 4 that earthquake caused Tsunami, although we called them tidal waves back in the day.

 

[demarpaint]

Originally Posted By: Bluestream
Originally Posted By: demarpaint
No one figured an earth quake of this magnitude, and there lies the major problem. I think the situation is worse than they are saying.


That's an understatement!.

Japanese PM had to hear about the last explosion when he was watching TV. Whatever you are hearing about this, multiply that by 4 times and you likely have the truth.


If you build Nuke plants, on one of the largest geological fault lines in the world, do you think there might be a problem some day??? Also, it was built for the quake, but the Tsunami caused most of the damage, as it was not designed for tsunami. Diesel generators were flooded as they sat low in the building. I learned in grade 4 that earthquake caused Tsunami, although we called them tidal waves back in the day.


We're on the same page. What I read was "the plants weren't designed to handle a quake of that magnitude", but could handle a quake of a lesser magnitude. I'm guessing quake would also mean the "tidal wave" that would follow, if not then there's another engineering screw up. No matter what it is a tragedy of epic proportions, and a lesson we can all learn from! Prayers sent.

 

[JHZR2]

Originally Posted By: Volvo_ST1
Originally Posted By: Al
Originally Posted By: Volvo_ST1
What I don't get is why the excessive pressure has to be vented into the atmosphere. Can't they design a reactor in a way that excess pressure can be released into a turbine that serves no purpose other than driving a coolant pump? Then you would have a perpetuum mobile of sorts, at least as long as the core keeps producing sufficient heat.

The only source of cooling available is ocean water boiling off. No matter where you send the steam its contaminated and has to go somewhere.


I was asking why the design did not include a system like the one I was suggesting. Such a system would be a closed system.


Problem is seawater will foul, making heat transfer less and less effecient.

 

[Volvo_ST1]

Originally Posted By: JHZR2
Originally Posted By: Volvo_ST1
Originally Posted By: Al
Originally Posted By: Volvo_ST1
What I don't get is why the excessive pressure has to be vented into the atmosphere. Can't they design a reactor in a way that excess pressure can be released into a turbine that serves no purpose other than driving a coolant pump? Then you would have a perpetuum mobile of sorts, at least as long as the core keeps producing sufficient heat.

The only source of cooling available is ocean water boiling off. No matter where you send the steam its contaminated and has to go somewhere.


I was asking why the design did not include a system like the one I was suggesting. Such a system would be a closed system.


Problem is seawater will foul, making heat transfer less and less effecient.


I wasn't suggesting to use seawater.

 

[Volvo_ST1]

Originally Posted By: Shannow
Would need a means of condensing the steam back to water to return to the reactor...a condenser.

After condensing the steam, store it in holding tanks.

Quote:
Then a pump to return the water, and another pump to circulate cooling water through the condenser.

The condenser would need a pump.

Quote:
All sized to extract the correct amount of heat from the failed reactor, in the condition that the reactor failed into.

Is over-cooling a core possible?


Quote:
And would require at least a rudimentary control system, powered by some sort of failsafe back-up electrical system (batteries or diesl generators), both of which seem to have been wiped out by the tsunami in this case, rendering it useless just like their existing emergency back-up systems.


Surely such a system could be designed?

Of course, I have no idea what technical issues may make such a system impractical or impossible. Maybe it would be merely a failure-prone complication.

 

[Al]

There are no pumps working bc the switchgear is all dead. There are multiple cooling systems in place. What you are suggesting requires pumps and coolers. Your system would just have more pumps and coolsers which wouldn't work either.

They can't even pump plaion old seawaterionthespent fuel cooliong pool.

Again to cool steam or water you need operating equipment. The only they have is to pump water on this molten jelly.

 

[OVERKILL]

Originally Posted By: Bluestream
Originally Posted By: Cause4Alarm
The nuclear incident in japan is now classified as a level 7 event, and it's believed that there has been a containment breach


But look at the bright side; they had a potential Chernobyl and turned it into a mere Three Mile Island...


Three Mile Island was a 5. This was listed as a 4 initially. Chernobyl was a 7.

 

[Drew99GT]

http://news.yahoo.com/s/ap/as_japan_earthquake

http://www.foxnews.com/world/2011/03/15/...ing-atmosphere/

I think it may be game over with this situation.

 

[Drew99GT]

http://www.abc.net.au/news/stories/2011/03/16/3164949.htm

France says it's a level 6 incident. Based on what some experts have indicated with good sourcing that contradicts the Japanese government, I wouldn't trust what the government is saying!

Could this radiation actually get into the jet stream? The nuclear plants are basically on the exact line of latitude of my area and the jet stream is right overhead this time of year!

Who's going to be looking for "made in Japan" on product labeling in the future??? This is going to cripple the already struggling Japanese economy.

http://online.wsj.com/article/BT-CO-20110315-705897.html

 

[Drew99GT]

http://www.zerohedge.com/article/tokyo-exodus-beginning

http://online.wsj.com/article/SB10001424052748703363904576201013720213564.html

 

[Drew99GT]

http://www.radiationnetwork.com/

Might want to bookmark that one! In addition, here's the jet stream looks like in the Pacific Ocean. It goes directly from Japan right to the continental US...

http://www.stormsurfing.com/cgi/display_alt.cgi?a=npac_250

If the worst case scenario pans out and all these reactors literally blow up like a dirty bomb, this isn't going to be good IMO.

 

[D189379]

It's unbelievable how much power the media has to spread panic. Are people seriously worried about radiation in North america from this? Ridiculous.

 

[Drew99GT]

Originally Posted By: D189379
It's unbelievable how much power the media has to spread panic. Are people seriously worried about radiation in North america from this? Ridiculous.


http://dcbureau.org/201103141303/Natural...-fukushima.html

"The problem is if the spent fuel gets too close, they will produce a fission reaction and explode with a force much larger than any fission bomb given the total amount of fuel on the site. All the fuel in all the reactors and all the storage pools at this site (1760 tons of Uranium) would be consumed in such a mega-explosion. In comparison, Fat Man and Little Boy weapons dropped on Hiroshima and Nagasaki contained less than a hundred pounds each of fissile material."

Um, yea. If that happens, and it is a big if, I''d be a bit worried!

 

[greenaccord02]

I'd only be worried if I lived in Japan, and then only if I lived within 50 miles of the plant. Even in a worst case scenario, you're looking at a fraction of the radiation people got during the atmospheric bomb tests and they did a LOT of those.

 

[JHZR2]

KI is sold out on the west coast...

 

[ltslimjim]

I know friends with thyroid conditions that take Iodine.

 

[greenjp]

The FUD is getting to critical mass here in this thread.

Nuclear reactor fuel is of a much lower "strength" than nuclear bomb material (heard the term "weapons grade"?) and thus a bomb-style explosion by the fuel in the reactor or spent fuel in the storage pond is not possible. Also, a nuclear bomb is ignited by a compression explosive or contact mechanism which produce temperatures and pressures greatly exceeding what could happen at the plant in Japan.

jeff

 

[greenjp]

Originally Posted By: Volvo_ST1
Surely such a system could be designed?

Of course, I have no idea what technical issues may make such a system impractical or impossible. Maybe it would be merely a failure-prone complication.

What you're describing is exactly the mechanism used by a power plant to produce electricity. water in, mix with heat, create steam, run turbine, condense water, repeat. You would generate a tremendous amount of water if you didn't recycle it. In case you didn't know, thoes big towers at a nuclear plant are the condensers. There is a huge amount of energy to remove. They are pretty impressive structures if you ever have the chance to be very near one.

Also the other safety features (control rods, boron, etc) are actually less complicated than a redundant steam turbine circuit would be, with all it's associated pipes, valves, controls, precision machined equipment, reactor penetrations, etc.

jeff

 

[JHZR2]

Originally Posted By: Drew99GT
Originally Posted By: D189379
It's unbelievable how much power the media has to spread panic. Are people seriously worried about radiation in North america from this? Ridiculous.


http://dcbureau.org/201103141303/Natural...-fukushima.html

"The problem is if the spent fuel gets too close, they will produce a fission reaction and explode with a force much larger than any fission bomb given the total amount of fuel on the site. All the fuel in all the reactors and all the storage pools at this site (1760 tons of Uranium) would be consumed in such a mega-explosion. In comparison, Fat Man and Little Boy weapons dropped on Hiroshima and Nagasaki contained less than a hundred pounds each of fissile material."

Um, yea. If that happens, and it is a big if, I''d be a bit worried!




As I recall, there are practical limits to how to produce weapons at substantial scale. My knowledge is only from Wikipedia, but IIRC, 50MT is about as big as has been done and has not been replicated.

Now this is a powerplant reactor, not a bomb, and even with energy release possible, is not optimized as a weapon... So dust?? Certainly a hazard. But any appreciable energy release? I'm not seeing it.

Maybe Mola or Al could suggest how the materials there have any similarity in capability for single pulse energy release... I'm guessig they will say that they cannot.

It's the dust that scares me, but that is why in my questions the other day, I asked how a release from a powerplant would equate to say an aboveground 20MT bomb blast, as I have to imagine that produced a good deal of radioactive dust, which we spewed all over AZ, NV, NM... All much closer than Japan...

 

[Shannow]

Originally Posted By: greenjp
In case you didn't know, thoes big towers at a nuclear plant are the condensers. There is a huge amount of energy to remove. They are pretty impressive structures if you ever have the chance to be very near one.


Nope they are the cooling towers.

The condensers are under/next to to turbines, and condense the steam using thousands of gallons per second of circulating cooling water through hundreds of miles of heat exchanger tubing, which is then cooled in the cooling towers and recirculated.