Monday, July 22, 2013

#Fukushima I Nuke Plant Reactor 3: It's Steaming Again from the Same Place, TEPCO Again Says Rainwater Warmed on CV Head

(UPDATE 7/23/2013) TEPCO measured the radiation levels around the area. See my latest post.


It rained in the morning at the plant. So, just like the previous incident on July 18, this one is explained as rainwater hitting the warm (about 40 degrees Celsius) Containment Vessel Head.

From NHK (7/23/2013; part):


"Steam" rising again from Reactor 3


At Fukushima I Nuclear Power Plant, what looks like steam is seen rising from the top floor of Reactor 3 building on July 23, following the same incident on July 18. As there is no change in radiation level above the building, TEPCO thinks it is the rain in the morning that seeped inside the building and warmed up. The company continues to monitor the situation.


According to TEPCO, the image captured by a video camera installed [on the top floor of Reactor 3] showed what looked like steam rising from the floor of the Reactor 3 building on 9AM on July 23.


There is no change in radiation level above the building, and the cooling of the reactor and the Spent Fuel Pool is stable. There is no data that indicate abnormality, according to TEPCO.

Since the steam was first observed on July 18, TEPCO has stopped the work to clear the debris on the operating floor of Reactor 3.

Nuclear Regulatory Authority told TEPCO to take infrared thermography of the location under the condition similar to the fist incident (raining), but TEPCO only heard the first half of the order - take infrared thermography. And take they did, on a sunny day on July 20.

I wonder if they had wits about them to take thermograph today (July 23), when it was raining. It looks like TEPCO will have another chance on July 24 and 25 (weather forecast in Fukushima is rain).


Anonymous said...

Tepco wants only one thing, know as little as possible, so you can be hold responsable as little as possible and that is very cheap for Tepco.
You should expect that Tepco tries everything possible to stay (officially) away from any information and only will confirm something, when all other possebilties run dry.
This is exactly the reason why the government doesn't want to take over, they want to know as little as well and now they can blame Tepco, even they own Tepco. For the public who is hardly interested, it's hard to understand who is to blame what and that is very cheap for the government.
No one to blame, so lets restart all the other NPP!

Anonymous said...


Anonymous said...

We're pretty screwed here, there, everywhere. Oceans are food basket of the world. Sky is the air we breath. Somehow we have managed to nuke both. Hopefully the next sentient species have respect for the world in which they share.

Anonymous said...

Well if cold shutdown is 100° C, one can boil eggs there, nothing amazing. And one might long be able to.

Anonymous said...

Huh? Water evaporating at 40° Celsius?
Wasn't it supposed to be 100°, at least at sea level?
My average body temperature is 36.5 °C, not that far from 40, isn't it?
So what? Each time i'm surprised by a summer thunderstorm and i get soaked with water, my body should be blowing steam all around like crazy?
Very, very strange explanation. Let's analyze facts:
1) the top of the CV is at 40° and it's enough for water to steam like that, or, at least this is what TEPCO says.
2) the molten core is supposed to be IN the CV (otherwise what should be heating the top of the CV?)
3) In order to have 40° at the top, to core itself should be at a significantly higher temperature, also considering that it is submerged with water, again, at least according to TEPCO words.
Now the question: if 40° are enough to let rain water boil, evaporate, stem like what we do see in the videos, that what with the water cooling the core? It should evaporate ten, hundred, thousand times stronger, isn't it?
Where is this steam? Where does it go?

Anonymous said...

Sorry for the typos: "stem" should be "steam" and "that what" should be "then what". Browser's Autocorrect in action ;-)

Anonymous said...

Oh God, thank you, Anon 2:11!! I'm - let's say - "scientifically challenged" and didn't dare to ask how rain or any other kind of water could possibly boil/steam with temperatures so low. Am glad to see this doesn't make sense to someone else either.

Apart from that, I was wondering how much heat would have to be generated in the RPV to heat up the containment cap to 40 degrees. How warm does the containment cap get under normal operating conditions?

Anyway, let's continue to assume that at atmospheric pressure at sea level, water boils/evaporates at 100 degrees - even in Japan. What in the reactor building could be generating this heat so that TEPCO's rain water could evaporate?

arevamirpal::laprimavera said...

mscharisma, I take a bath and the bath water is seen steaming at about 40 degrees Celsius. It's a matter of temperature difference and humidity in the air.

Anonymous said...

Yes,arevamirpal::laprimavera, you're right, but this still doesn't answer the question. Even when peeing, in winter sometimes i can see condensed vapour raising from the toilet. That's the point: winter! Cold air! We are in summer! Which is the temperature now in Fukushima? When this whiff of steam has been seen? Early in the morning? At twilight? Midday?
But the real question is: how can it be that the top of the CV is at 40°C?
Is TEPCO measuring the metal cap's temperature? Or are they measuring the air temperature within the CV, close to the top?
As far as i know, penetrations are supposed to measure the temperature within the CV, NOT the temperature of the CV itself.
Am i wrong?

Anonymous said...

laprimavera: thanks. I can understand that a body of water (i.e., bathtub, pot, etc. full of it) produces steam under the right conditions also if it is below 100%. But water drops hitting a surface that is 40 degrees while air temperature is anywhere between 20 and 30 degrees?
Again I can only think in completely non-scientific ways: outside temperature at my house is about 30 degrees, terrace floor in the sun is significantly warmer and hot to the touch, summer rain hits - but not a whiff of steam.
What am I missing?

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