Saturday, July 9, 2011

#Fukushima I Nuke Plant: AREVA Chemical Leak Photo

TEPCO posted the photo of the joint that leaked. It sure doesn't look like it is meant to be connected this way. Any machinists, pipe fitters, engineers care to comment?

There are at least 6 other joints like this, according to TEPCO.



The dotted red circle near the center bottom is where the leak occurred, right before the pipe goes to the coagulation/coprecipitation unit. I added the labels indicating whose system they are.

10 comments:

Anonymous said...

No, that does not look correct. It looks like some kind of flare or compression type fitting attached to a welded in nipple that has pipe thread (NPT).
Not a valid combination, if that is what it is.

Anonymous said...

At what stage is this fitting at? Not only do they have to put up with chemical corrosion but they also will be getting concentrations of highly radioactive material buildup at joints like this. It won't go critical but there could be chemical heat reactions going on. Makes you wonder why they used plastic pipe for any of the system.

They're definitely a bunch of crazy fuckers that don't know what they are doing, that's for sure. They expect to cool a hundred tons of melted nuclear fuel in each reactor with three tons of water an hour. A ton of water is one cubic meter. Do the math. They say the reactors were SCRAMed after the earthquake, that all the control rods were in place. For reactor 1, this state lasted for less then four hours at which time the control rods were melted along with the fuel... which could again reach full criticality. The other two reactors followed a couple of days later when the steam powered cooling ran down. Same thing, Fuel melt, full criticality. For sure, the concrete biocap was blown off the top of number 3 reactor. Who know what that pressure vessel looks like but there's probably not much left of it by now.

arevamirpal::laprimavera said...

@anon at 8:53PM, it looks like it is right before the coagulation/coprecipitation unit. I'll post the diagram (for now in Japanese).

I could be wrong, but the system when it was an active plant in Italy must have used metal pipes. Probably the same here. But the pipe was cut when they disassembled and transported the system. And time was of the essence for TEPCO, so they used PVC hoses and couplers instead of welding. I guess the space was of the essence, too.

pat said...

if that's PVC it won't last long.
The heat, radiation, and chemicals will destroy it.

Anonymous said...

This looks like a dosing port, and fairly typical. I do not think I would spec that for a nuke plant though.

Anonymous said...

That ribbed PVC tubing, rated at 400 psi, didn't last 2 weeks with a chlorine dosing application. Just had it replaced yesterday. The ribs are its weakness. Use braided. In this case, it is hard to believe it they say it was the weld that failed.

Anonymous said...

correction. Just took a look at the drawing, and likely the tube, not weld, failed (contrary to what is stated above).

Anonymous said...

ex-skf, I'd appreciate it if you could comment on this article. the Google translation here is even more useless than normal.

thanks

http://enenews.com/worse-than-melt-through-a-melt-out-see-graphic

Anonymous said...

The pvc looks like an instumentation wiring conduit. The stub is a bung likely a thermal-couple or flow guage....

There is a fresh weld in the background.

The bung fitting weld could have failed too.

Sheeps

Anonymous said...

It is hard to tell from the field of view, but it looks like the tubing is placing tension on the pipe fitting, not optimal to do so.

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