Why might it take "months" to contain Fukushima? What process dictates the timeline?

[DisgustipatedinCA]

Officials keep vaguely saying that it may take months to completely contain the accident at Fukushima. I understand they're hedging by staying vague, but beyond that, what is it that can be done in this timeframe of "months"? I know that under normal circumstances, control rods are placed into the fuel, and the nuclear reaction is stopped. I'm also given to understand that in a meltdown situation, you can't just drop tons of concrete, earth, etc onto the pile of material, because pressure would eventually build enough to cause an explosion (conventional) that carries radioactivity high into the atmosphere.

So assuming the control rods and whatever they're sheathed in are destroyed, and assuming that the damage to the machinery is too great to repair, what's to be done about this? Does the decay of some of the radioactive elements happen at a quick enough pace that it will be safe to bury the remaining non-inert material in several months' time? What's the end state for this pile of radioactivity? What's the plan?

[FourScore]

1. I have been wondering the same thing.

Remember when they said it would all cool down as time passed? I think 24-48 hours was the timeframe they gave.

[Paradoxical]

2. If they must entomb the reactor it is a very tricky procedure.

It requires a massive amount of man-power. Each worker can only be exposed for a few minutes at a time.

That's not including the possibility that the reactor has been breached and it seeping into the ground; possibly effecting the ground water. That could take years to fully contain.

[Whisp]

3. the plan is CYA

most of the people that are affected won't die from exposure for years ahead and history gets rewrit about most everything. The lawyers lines will be PROVE IT. Just like the tobacco industry. and others.

[aquart]

8. Yes, yes, it's all a terrible evil plot.

BUT HOW DOES THAT HELP WITH POISONED GROUND WATER? Yes, there are bad and greedy people. Do write a polemic condemning them because we don't see enough of those.

I'm sorry you feel helpless. So do I.

[Whisp]

10. of course I'm helpless. I don't have to apologize for it.

what can I do but recognize the corruption and know it weller than I want.
I can't do shit, and neither can you.

[Selatius]

4. It will take hundreds of tons of entombing material to cover one reactor.

The entombing material should include elements that could dampen or lessen the radioactivity of the fuel rods. The Soviets used sand laced with large amounts of Boron to entomb the exposed reactor at Chernobyl. A more permanent solution they used was concrete laced, again, with Boron.

This will require a major air lift. If the loss of human lives are not the issue, then instead of air dropping, one simply sends in crews with large numbers of dump trucks and bulldozers to push the material over the reactor cores. This is done with the recognition that the crews will be lost to radiation. Several hundred plant workers at Chernobyl died to entomb the reactor there, but it saved countless more lives from radiation poisoning in the process.

[DisgustipatedinCA]

5. Thanks. Your answer begs another question...

Why aren't they doing this now? Surely we'd hear if they were preparing to airlift all the tons of material to cover the sites. Since they're not doing this, does it mean they think they have a hope of getting all of the reactors shut down? Or are they trying to reach some point of a little more stability before trying the entombing solution?

[Selatius]

7. It could be they are still debating on the next course of action.

They've probably never had a back-up plan for the scenario where all back-up power sources to run the coolant pumps were destroyed at the same time, leading to partial or complete meltdown of the fuel rods.

If this is true, they likely are doing this by the seat of their pants. They are in uncharted territory and are making it up as they go. Of course, when you are doing something for the first time, it takes a lot longer to organize and execute the procedure vs. a situation where you've drilled countless times and can do it automatically, as opposed to sitting there and thinking about each step you take and whether that step is the right one.

Even if they decided right now they are entombing everything at Fukushima, it will still take a very long time to mix the material and then deliver the material on top of the reactor cores as well as spent fuel rod pools.

[aquart]

9. Question: The reactors are failing, breaching, melting down at different rates.

They have different amounts of damage and different amounts of fuel. Is that part of the delay in a final solution?

[Selatius]

12. Personally, I think the delay is caused by a mixture of sheer denial and dumbfoundedness.

If they are in denial that the situation is that bad on the ground, then the authorities could simply be operating under the tragic assumption that those reactors and the facility can be saved like it's just another Three Mile Island incident. On the other hand, the simpler explanation is they simply don't know what to do now. They obviously never had a plan in place in the event Fukushima was struck both by an earthquake and a devastating tsunami, so now they have to start from scratch creating a plan to entomb those broken things. Good luck to them.

[bananas]

6. There are reactors and spent fuel pools

and the spent fuel can be just as hot as the reactor fuel, but it it doesn't have a containment structure, and contains many more rods than the reactor.

[kristopher]

11. i think the answer was in the paper yesterday.

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x283622

"According to calculations by Koide, decay heat has decreased to minimal amounts compared to when the reactor was actually operating, but the fuel rods still have about 6,000 kilowatts of energy in the No. 2 and No. 3 reactors. The energy will only gradually reduce to about 3,000 kilowatts after six months and to 2,000 kilowatts after one year."


I believe that presumes they have everything under control.
I don't think that is the case.

[Tesha]

14. And that, presumably, is speaking of the fuel rods in the reactors' cores.

There's much more spent fuel in the various spent
fuel pools but it's also farther down the radioactive
decay road.

Tesha

[DisgustipatedinCA]

15. Thank you...good information

I also agree that if there's a presumption everything is under control, the presumption is demonstrably false.

[PoliticAverse]

13. There are no easy choices at this point...

They still don't understand the full extant of the damages at the 4 involved reactors and are still working to
try to mitigate the damages.

Note that in the case of the Chernobyl sarcophagus they had to tunnel under the reactor to install a concrete buffer.
The sarcophagus construction took months.

Chernobyl sarcophagus: http://en.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant_sarcophagus