Sunday, February 12, 2012

Reactor 2 RPV Bottom Temperature: 89.6 Degrees Celsius, 5AM on Feb 13

(UPDATE: The latest number is 91.2 degrees Celsius as of 10AM, 2/13/2012.)


For nearly 18 tonnes/hour water injection, the temperature hasn't dropped a bit. It remains high at 89.6 degrees Celsius at the Pressure Vessel bottom, but we're not supposed to worry. It's all nothing but instrument failure, as TEPCO and NISA have assured us.

From TEPCO's plant parameters, 2/13/2012:


Chibaguy said...

So the PM declares state of cold shutdown to the dismay of everyone watching (including TEPCO workers) and now TEPCO is forced to do the impossible. TEPCO is literally battling an instrument and everyone thing they are doing is leading to higher temperatures while creating more radioactive water.

Anonymous said...

Well not everyone was dismayed. Fukushima officials were happy, so were lots of residents there and in Kanto. TEPCO's headquarter people couldn't care less, because they are not at the plant. (Workers at the plant are a different story.)

netudiant said...

TEPCO estimates the residual decay heat in reactor 2 is 0.6 megawatts. That will boil a lot of water unless the heat is continually flushed away by flowing water.
Unfortunately, the inside of the reactor is damaged, so smooth cooling water flows are unlikely. It is most reasonable to assume the sensor is measuring a hot spot, where accumulated fuel is still producing decay heat faster than the water is taking it away. Eventually, that area will boil, adding a bit to the steam the reactor continues to produce.
The only problem is that this contradicts the claim the reactors are in 'cold shutdown', a meaningless phrase for reactors whose cores have all been destroyed.

PS: EX-SKF, there is no reason to let some nut abuse people,you included, on your own blog. Just cut off his postings, let this type chat with itself. They add zip to the discourse, other than to remind everyone how thin civilization really is.

arevamirpal::laprimavera said...

@netudiant, thanks for your advice.

And your analysis, it makes sense. There are other places where temperature is either trending up a little or remains relatively high: CRD Housing, and RPV bellows seal at the flange. TEPCO claims the former as instrument failure, though it doesn't look that to me.

Andrew Spagnoli said...

CRD is a very logical hot spot. As a penetration of the vessel at the bottom end, it is exactly the sort of spot for fuel to melt through. As always, however, Tepco chooses the least likely and most benign explanation for every anomaly. In a complex system that carries risks to the public (like a nuke reactor) sound and responsible engineering principles require that we assume the worst, not the best, when we unknowns or conflicting data. Imagine waking up to the sound of your toddler crying and the smoke alarm going off in the basement. Would you evacuate the kids then? Or go back to sleep telling yourself: only the basement alarm is sounding not the one outside the bedroom so checking the basement is too much effort. OF COURSE YOU WOULDN'T. YOU CARE ABOUT YOUR FAMILY... does the nuclear industry care about them?
What dou YOU think?

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