Saturday, July 2, 2011

#Fukushima I Nuke Plant: TEPCO Starts Full Circulation Cooling of Reactors

The whole process is as follows:

  1. Take the highly contaminated water that has been stored in the Central Waste Processing Facility (about 120,000 tonnes of it) to the water treatment system;

  2. The water first goes through the oil separating system built by Toshiba;

  3. The water then goes to the system by Kurion, where different types of zeolite will remove 1) the oil/technetium, 2) cesium, and 3) iodine;

  4. Then it goes to the system by AREVA, where it gets further decontaminated; if TEPCO decides so, the AREVA system can come before Kurion;

  5. Then finally it goes to the desalination system built by Hitachi.

  6. After desalination, the "treated" water is stored in a series of tanks;

  7. The treated water is fed through the 10-centimeter diameter PVC pipes to the Reactor Pressure Vvessels of the Reactors 1, 2, 3;

  8. The water will leak through the RPVs and the Containment Vessels down to the reactor basements;

  9. Again highly contaminated, the water then is routed from the basements of the Reactors 2 and 3 to the Central Waste Processing Facility;

  10. Start at No.1 again.

To see the convoluted schematics, see my post here (opens new window).

As of July 2, TEPCO is injecting:

  • 3.5 tonnes/hour to the Reactor 1;

  • 3.5 tonnes/hour to the Reactor 2;

  • 9 tonnes/hour to the Reactor 3;

  • Total 16 tonnes/hour or 384 tonnes per day.

The water treatment system is processing more than that amount, even at the current 55% capacity (full capacity 1,200 tonnes per day). So, at least for now the highly contaminated water will not increase, and slowly decrease.

What's missing from this process is the cooling system for the circulated water. TEPCO is counting that by going through the treatment system the warm/hot water (remember the 4-sieverts/hour steam gushing out of the Reactor 1's basement) will cool off enough.


greenpharao said...

Good and helpful description of the process. Thank you.

But this is what I don't understand yet:

The water will leak through the RPVs and the Containment Vessels down to the reactor basement of UNIT 1. But no water is pumped out of the basement of UNIT 1 to the water treatment facility or storage.
Doesn't that mean that the water levels in UNIT 1 ands its Turbine building are going to increase at a rate of 3,5 tonnes/hour???

What's your take?

arevamirpal::laprimavera said...

The water levels at Reactor 1's turbine building and reactor building are unchanged to slightly decreasing. My take? Well the water has to go somewhere. It's either leaking out of the buildings into the ground or evaporating rapidly due to high heat or both. From that video of the 4 sieverts/hr steam coming from the basement, the Reactor 1's water is hot and "hot". Why is it so hot, compared to other buildings? My guess is that the corium is out there, in the water. So TEPCO dare not touch that water, because it's too hot.

Robert said...

As an engineer it seems to me like this scheme has a reasonable chance of working provided the equipment can handle the maximum radioactivity levels that may be encountered, and personel can get close enough to install it and correct any problems that may occur. Is it a long term solution? No, I do not believe so. They may have to tunnel beneath the reactors to install impermeable barriers to prevent the core material from digging further into the ground and contaminating the ground waters. This would be a catastrophe beyond redemption or remediation,as this aquifyer can travel long distances underground. This procedure was done at Chernobyl. This must be done soon as every day delay makes that effort more difficult, if it is indeed possible at this late date. I wish them luck for all our sakes.

Anonymous said...

Reactor 1 does not appear to be the more active steamer, so it's gotta be going somewhere.

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