Fukushima No. 1 loss of coolant due to earthquake 7

[vanmorrison]

Yes there will be lessons learned, recommendations and plant modifications I am sure. However, nothing can be designed/engineered to withstand all Acts of God. We may think we have control but it is an illusion.

 

[trottiey]

racookpe1978's post is grossly misinformed. Hydrogen would never be used as an industrial coolant because of the explosive risk. Nuclear plants use lots of helium and some liquid nitrogen, but not hydrogen. That would just be stupid.

I've looked at a lot of pictures and videos of the accident, before, during and after, and I am quite convinced that it is the reactor building that blew up. There are reports that the containment structure is unharmed, but I'm think that's just a product of the language barrier and non-technical reporters. And political bloggers spouting nonsense.

Maybe they mean the pressure vessel is intact, or maybe they just mean the containment well still holds water, which allows it to be flooded with ocean water and boric acid. But the "containment structure," in the sense that english-speaking nuclear engineers use the term, appears to have failed.

 

[Power2go]

Now I get confused by trottiey's reply to the hydrogen cooling issue of generators. Doing some "googling" I have found numerous examples of large generators with hydrogen cooling.

ABB has a whole range of these with the appropriate Gas Analyzer Systems for Hydrogen-cooled Alternators. Go to their site to find examples of these generators.

When you follow this link (copy/paste)

http://www.powergenworldwide.com/in...quate-cooling-of-generators-is-essential.html

or search with "cooling large generators" in Google you will find enough info on this subject.

 

[DrRTU]

My guess, D/Gs were lost with tsunami . Small primary leak, H2 released as core goes past 2,200 F without cooling. Explosion results in containment building during venting.

 

[trottiey]

I apologize. Some google searching shows that I am plainly wrong about the use of hydrogen as coolant. I was not aware and am quite surprised by it.

 

[jpankask]

Actually trottiey, you are incorrect. Hydrogen is used inside the generator for cooling.

When they say the containment structure is unharmed, they are referring to the inner steel containment shell. Some reports I've read indicated the outer containment concrete was damaged, but the steel lining was still intact. In other words, the containment structure is still providing it's function of containing the atmosphere and maintaining pressure boundary so that any releases to the environment are done on purpose, to control containment pressure. The fact the containment pressure is higher than normal indicates the containment structure is working, though with less concrete reinforcement than designed.

 

[DrRTU]

Trottiey, rocookpe1978 is correct, most large generators are cooled with 100% H2. This is a very safe proven system of cooling. The H2 seal oil unit is very important system that keeps the H2 and oil away from an explosive condition. This system are in fossil power plants. The generator & H2 systems are in the building that did not blow-up.

 

[trottiey]

Yes, I've learned something today. Rocookpe1978's idea is plausible, and I apologize for dismissing it so harshly.

I still think it was the reactor building that blew up, not the turbine hall.

 

[unclesyd]

Just watching the news when they showed a new clip on the power station station it appeared hat the dust cloud started forming almost instantly quite a blast wave emanating from the dust. It had some color to a height just a little over the height of the vent stacks. Color indicates something is been burned along with the H2 which would have no color. There was no sound just images.

 

[OperaHouse]

I believe one news report said this was a BWR, Boiling Water Reactor. Believe GE reactors were all BWR and Westinghouse were all PWR. The BWR reactors were considered much safer. These had two 10,000HP pumps to control the reaction. Thes were not cooling pumps but it gives you a flavor of how big the cooling pumps probably were. The faster you ran the pumps ther more power you got out. This was to get rid of the bubbles in the reactor that slowed the reaction down. No pumps, the power is very low. This is contrary to what you might think. And certainly there is still a lot of heat generated if there is no place to dump it. Further reduction of power is done by removing the rods. I'm sure wiki has a better explanation and I havent been in a plant in 40 years. Keep this in mind that these plants are probably that old. Japan had a lot of protests about building new plants. We had protests about every week when it waqs under construction.

 

[zzzjim]

Looking at Satellite news , a very clean spherical shape rises quickly
above roof , any coloring could be a lense effect of hot gas ,
Hot Hydrogen will explode very suddenly mixed with Air .
This appears before Dust shoots out , from building collapse !

 

[owg]

Trottiey - Thanks for the response on the hydrogen and oxygen. However I am still not clear how the tritium would "float away" while leaving the hydrogen behind. Hydrogen has a mol wt of 2 and Tritium has a mol wt of 6. I would not expect much separation by gravity. What am I missing here?

HAZOP at

http://www.curryhydrocarbons.ca

 

[trottiey]

Nitrogen (air) has a molecular weight of 28, so both the hydrogen and tritium will float away quickly. Some of it (both hydrogen and tritium) will recombine with atmospheric oxygen and fall back to the ground as rain.

 

[byrdj]

I found an informative posting by a Nuclear Engineer, of all places, the Talor Swift Fab club. It is actually some one else quoting. Sure wish I could find the originating forum.
well worth the read

http://connect.taylorswift.com/forum/thread/33330/Pray_for_Japan_Swifties/3

 

[electricpete]

Taylor Swift fan club... Lol.

=====================================
(2B)+(2B)' ?

 

[rmw]

I would note that once all power had failed there was nothing to operate the pumps to maintain the hydrogen seals on the generator(s).

rmw

 

[Zogzog]

Swifties! LOL!

 

[rmw]

I guess I need to get out more.....

rmw

PS: ByrdJ, you seem to get out too much

 

[byrdj]

I found the original poster. He is an SRO and post by the name Fermi2.

http://warships1discussionboards.yuku.com/topic/15893/8-9-Earthquake-Tsumani-in-Japan?page=3

 

[byrdj]

rmw, I was just google for BRW and hydrogen venting and got a hit there.

Being somewhat familar with a BWR plant, I find fermi's discriptions to be accurate