Sunday, April 10, 2011

Robots in Japan, just weeks late. Return of the Blob!

It is good to see they are putting some proper infrastructure in place.  Too bad this didn't happen 3 weeks ago.  

The bad part is, it is also an admission that there are spots "too hot" for humans to work in.

Korea being very critical of the way this disaster has been "managed"

I think there is little likelihood that "restoring" the existing cooling systems will actually work.   In fact it seems beyond absurd, as most of these building have had earthquakes, floods of seawater, and large explosions.

It is 100% clear-cut, one or several reactors are breached and the nuclear materials is undergoing fission--an out of control nuclear reaction, perhaps up to 5000 deg F, which melts steel and can't be that great for concrete especially after a major earthquake.  

The "blobs" of 5000F radioactive uranium/plutonium must be cooled and seperated by distance and intervening material, i.e. the same material as the control rods.  

It may even be hard for a robot to even get to the "blob" with the building wreckage.    And if the robot gets close enough to shovel up a bit of the blob and drop it into a tank filled with balls of the control rod material, the robot might burn up in the process.

So a massive cooling effort must first be done, releasing an incredible amount of radioactive steam that has no choice but to go into the atmosphere, THEN, the separation and control rod material insertion needs to take place....and it would be best if this was done simultaneously at all reactors that have "blobs" undergoing fission reaction.  See CONTROL MATERIAL below

There are problems---do they actually know where the "blobs" are?  Some Blobs could have leaked through the concrete floor and be underneath the building.   Remember a few weeks back how TEPCO was saying their cooling operation was "partly successful" because they saw steam coming out from underneath the building?

Do they have robots that can perform the required dextrous and muscular functions at the same time, and do they have trained operators who understand the robot control and the physics?

Given the poor handling so far, I would say there is little likelihood that the current team is up to the task.

There is something like 2.5 million pounds of radioactive material located on that one Fukushima site.   They should be off loading reactor 5 and 6 (basically they are storage facilities) and driving that material to another site.

One property which is a must for control rod material is the heavy absorption capacity for neutrons so that they can carry out the control function effectively. The commonly used materials which satisfy these criteria include cadmium, boron, iridium, silver and hafnium. Another property of control rods is that the material should not start a fission reaction despite the heavy absorption of neutrons. Infact you can imagine the function of a control rod just like a blotting paper which sucks the extra ink that has spilled somewhere but doesn't let it spread in a wider region.
Cadmium     ---    321 C                    610F
Boron          ---    2300 C
Iridium        -----  2410 C
Silver           ----   962 C
Hafnium      ----   2152 C

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