Thursday, April 12, 2012

Fukushima Plans Revealed To Remove Fuel from SFPool #4

[Fukushima Nukeblog]

Just recently , information has surfaced, but not in the US press that TEPCO has completed plans and started construction of a building to remove the spent fuel from the spent fuel pool at reactor 4 and take it out of the building, perhaps to another pool onsite. The fuel is still too "hot" for general transport, but needs to be removed since it is believed that the reactor could collapse in another strong earthquake. If the pool were to spring a leak or collapse entirely, the fuel could start a massive fire which would definitely require evacuating Tokyo and even cause harmful levels of radiation on the US west coast. 

Most of the info is in Japanese, but it looks like they plan to build a shell around reactor 4, like the one at #1, and make another stronger building over the spent fuel pool so that rods can be put into a cask under water, and then lifted over the pool and onto the ground where the cask will be put onto a truck. 

This solves the problem of how to get the fuel assemblies off site, but keep them under water and shielded at all times.

Fuel pool at #3 is much worse as it is filled with wreckage, and fuel bundles likely cannot be lifted simply by their handles in one piece. They may have been broken by the explosion and fallen debris. 

This info is from the simplyinfo hipchat group.


Reactor-4-Cover.jpg 20K

from that link the building over a building


It looks like they are either installing a new overhead crane or removing the old one. In either case, it is huge, much too large to put on a truck. I don't how they would move such a thing around except on a barge.

11:26 AM

the refuelling bridge ?

This is enformable's article looking back to last year when Atomic Arnie speculated on what the heck they could do with unit 4. So Arnie did some things right, maybe the people at TEPCO got some ideas from him.

Plans for Fukushima Daiichi Reactor 4 cover revealed on same day TEPCO applied ...
The latest projected completion date for the nuclear waste processing plant was October 2012, but it was delayed again after another problem was found in February. Therefore, the fuel removed from the common pool has to be stored at Fukushima Dai-ichi ...

Plans for Fukushima Daiichi Reactor 4 cover revealed on same day TEPCO applied for 1 trillion yen injection of public funds

In June 2011,  Arnie Gundersen of Fairewinds Associates was featured in a podcast hosted by Chris Martenson. The show updated listeners as to some of the latest events surrounding Reactor 4 and groundwater monitoring concerns, I will only highlight a few of the details, the entire podcast can be found here.
Chris Martenson: What can they really do beyond just keep trying to dump water in there and keep their fingers crossed?
Arnie Gundersen: If you put too much water in these reactors they get heavy, and they are not designed to sway when there is heavy – tens of tons of extra water in them. So they are really not designed to sway. So let’s say there is a severe aftershock, Unit 3 and Unit 4 are in real jeopardy.
Chris Martenson: Is there some way that they [TEPCO] can maybe just throw up their hands and just pour a bunch of concrete on it and call it a day?
Arnie Gundersen: I think eventually they may get to the point of throwing up their hands and pouring the concrete on.
They can’t do that yet, because the cores are still too hot. So we are going to see the dance we’re in for another year or so, until the cores cool down.
At that point, there’s not anywhere near as much decay heat and you probably could consider filling them with concrete and just letting sit there, like we have it at Chernobyl, as a giant mausoleum.
That would work for units 1, 2, and 3. Unit 4 is still a problem, because again all the fuel is at the top and you can’t put the concrete at the top because you will collapse the building and it’s so radioactive, you can’t lift the nuclear fuel out. I used to do this as a living and Unit 4 has me stumped.
Chris Martenson: So what do they do, do you think?
Arnie Gundersen: I think they will be forced to build a building around the building and then, because you need heavy lifting cranes – cranes that lift a hundred and fifty tons, which are massive cranes, to put the put the nuclear fuel into canisters, which then can get removed.
That is sort of what happened at TMI, but all of the fuel at TMI was still at the bottom of the vessel. But it was a three-year process to get the molten fuel out of Three Mile Island – four years actually.
So the problem here is that all of the cranes that do that have been destroyed, at least on units 1, 3, and 4. And you can’t do it in the air. It has to be done under water.
So my guess is that they will have to build a building around the building to provide enough shielding and water, so that they can then go in and put this fuel into a heavy lift canister.
Chris Martenson: Okay, all right, I hadn’t considered that. That’s a great insight.
Almost a full year later, anyone looking to verify Arnie’s observations about Reactor 4 will find once again they ring true, and TEPCO is in fact thinking of constructing a cover for Reactor 4.
On March 29, 2012 TEPCO announced that it applied for an injection of 1 trillion yen in public funds.
On the same day TEPCO, through NISA, released the details of a new steel frame structure to be built around Unit 4 for recovering the fuel rods from the pool.
The inverted L shaped structure will be self-supporting and only the part carrying the fuel handling mechanism will be bolted to the wall of Unit 4.
The design of the 51m tall structure, to be covered by steel panels, will be completed by the end of June and construction will start this fall.
In preparation for the construction the remaining parts of the outer shell, pillars and roof of the 5th floor on the north side of Unit 4 needs to be removed, and this work will be completed by the end of June.
The crane to lift the fuel from Unit 4 is expected to be manufactured in the third quarter of 2012.

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