Wednesday, January 1, 2014

#Fukushima I NPP Reactor 3: Debris Removal from Spent Fuel Pool Has Started


There were a few news outlets in late November and early December last year that reported TEPCO would start removing the debris from the Reactor 3 Spent Fuel Pool at Fukushima I Nuclear Power Plant in mid December. Hardly anyone paid attention. (No one probably thought it was possible.) Then there was no news of it actually starting.

Well, news or not, the work started on December 17, 2013. That information was shared at the meeting on December 26, 2013 on "Roadmap to Decommissioning", which was available via live feed on the net. However, unless you are one of the dwindling number of reporters and net citizens who continue to follow the accident by attending/watching such meetings, you wouldn't know.

I didn't know because I couldn't watch the whole meeting and didn't take a look at the entire document that contained the information until now.

There is no photos or videos posted at TEPCO's site (in the Photos and Videos Library).

From the 242-page document presented at the December 26, 2013 meeting of "Roadmap to Decommissioning" (pages 152-158):

The slide says:

In order to remove fuel assemblies from the Reactor 3 Spent Fuel Pool, removal of large-size debris in the Spent Fuel Pool started (December 17).

Reinforcing bars and deck plates that won't interfere with the Fuel Handling Machine [number 8 in the 3-D model] will be removed by the first half of February 2014.

The incident that caused the video camera to drop into the pool has been investigated and the countermeasures put in place.

The order of large-size debris removal:

0. Measures to prevent [additional] debris from falling into the pool (by covering with liners)
1. Remove reinforcing bars, deck plates (1->2->3) - Current work
2. Remove masts, trusses (4, 5, 6, 7)
3. Remove the Fuel Handling Machine (8)
4. Remove the end-track on the west side of the Fuel Handling Machine (4)
5. Remove debris from the cask area (10)

Enlarged images:



3-D debris map from a different angle, and the location of the video camera that dropped into the pool in November last year:


Kyodo News reminded readers on its 12/2/2013 article that there are 52 new (not irradiated) fuel assemblies and 514 spent fuel assemblies in the Reactor 3 spent fuel pool.

Kyodo also reports that two cranes will be used, and up to 11 monitoring cameras will be used. All the work will be done by remote-controlled vehicles and equipment. No information whether the human workers are to be posted near the work for further safety monitoring.

All of the MOX fuel that TEPCO had at the plant was in the reactor itself at the time of the accident.

15 comments:

netudiant said...

That is quite an impressive achievement.
Pulling out debris without causing additional damage is difficult enough, doing it from the end of a remote controlled boom is unprecedented, afaik.

That said, how can the cranes be positioned so near to reactor 3 when we recently saw pictures that showed the area still littered with accident detritus?
If memory servers, the reporters that visited the site earlier this year noted that the radiation level was notably higher around reactor 3 and that they drove past it at speed. So working near there has to be very challenging.
Also, I'd thought there had been some very radioactive debris between reactors 3 and 4 that had just been bulldozed over shortly after the accident. Has that been removed?
It seems that this cleanup is highlighting both the best as well as the worst of Japan, really pathbreaking technical achievement on the one hand alongside of the sleaziest human exploitation of desperate homeless people on the other.

arevamirpal::laprimavera said...

I think they cleared just enough space for the cranes and to build a structure around the building to serve as platform, on which smaller cranes have been placed to remove the floor debris.

Totally agree with your last sentence.

Anonymous said...

Where are the experts who should be screaming "end of the world is here"?

Anonymous said...

We're all gonna DIE!

Anonymous said...

Oh thank you, expert.

Anonymous said...

We have a winner for today's "NOPE!" award. Prize awarded at very end.

"Pulling out debris without causing additional damage is difficult enough, doing it from the end of a remote controlled boom is unprecedented, afaik."

"unprecedented"? NOPE. see the CanadaArm on the space station, far more exacting, I'd say.

However, inspired by "piffle" in the recent past and seeing as it more accurately reflects the adulatory quality of some's descriptions of TEPCO-fouk efforts,
We hereby nominate "netudiant" as most-worthy recipiant of Netudiant "Hot Buns", ever-offered at the Fouk-U Shrine, as it were.

hahaha

We can only now "presume" we'll shortly be finding out the source of heat for #3's steam events.
If we don't, and netudiant fails to note we have not, we will presume failure to find & identify that heat source is also evidence of "at speed" "pathbreaking technical achievement[s]".

Clear? enough?

Anonymous said...

Agree with anon @8:22
This disaster is only highlighting the very worst of Japan, or maybe it is simply exposing the usual Japanese methodologies of psychopathic hubris, pathological inability to tell the truth, with blind ambition being the better part of ability.

Where is the fucking integrity in Japan? Where is the honesty?

Anonymous said...

To liken use of these hydraulic shears to "unprecedented" is definitely good humor,
http://1.bp.blogspot.com/-PcxcJp90vsM/UsSqg4qVM4I/AAAAAAAAGko/5Llkb4Ss4DU/s400/Reactor3SFPDebrisRemoval-1.jpg

The space station astronauts would almost certainly get a good laugh out of that.

Anonymous said...

In the roadmap document there are readings for drainage pipes up on the hill that had some high soil readings but didn't appear to be near the known tank leaks. Machine translation of that section didn't help much. Any idea what is going on in that area with the drainage pipes?

netudiant said...

To anonymous @8.22
I'm quite aware of the Canadarm on the space station and other remote manipulators. They are nowhere near what is being attempted here.
The task here is to gradually remove debris of uncertain strength from a debris field, partly in water, without doing further damage to the remaining fuel racks. The grabbers are mounted on dangling wires, subject to wind, sway and twist.
Maybe you watched the earlier camera shots. They illustrate how this is a much more challenging work environment than space or hot boxes.
It is also obvious that cleaning out the reactor 3 SFP will do nothing to address the steam generation visible from reactor 3. So what? We can assume that the steam reflects heat generated from residual core material decay. That is why the site gets soaked with hundreds of cubic meters of additional cooling water every day, even though the water management is a major headache.
TEPCO is beginning to tackle one additional problem, the reactor 3 SFP. I say, good on them for that.
Feel free to criticize, there are lots of targets, but please recognize good work when it gets done.

Vyse Legendaire said...

I'm really wondering what their plan will be to remove the actual spent and unused fuel assemblies from the pool, if and when they can complete this major debris removal. AFAIK, its not even remotely feasible for human workers - due to the extremely high radiation - to hang out around there long enough to build a spiffy building and do delicate operations like it appears they are at Unit 4 SFP as we speak.

Anonymous said...

"The grabbers are mounted on dangling wires, subject to wind .."
Where did you see that stated?

Even if it is dangling from a crane, the business end of it is thoroughly submerged and is possessed of considerable mass, so knowing how massive objects behave underwater, they won't be experiencing much sway.

It is heartening to see it actually getting done. And I'll reemphasize my earlier point: Now is when we should see the gameplaying with this reactor's radiation levels and components whereabouts End.

Should.

Making fun of these things is understandable. And although I haven't been on the space station, I suspect microgravity has its quirks when moving massive objects, too.
It's a slow dance for a reason. Momentum, precision, costliness, etc.

Calvin Cheney said...

Dr Deagle on Rense.Com is making an educated guess that by March or so there will be a terrible earthquake that will cause complete evacuation of the site and require Tokyo to be abandoned. Complete destruction of the Japanese economy. I've followed this since it happened. It is a global death warrant to continue forward with nuclear energy. This event itself still contains the potential to leave the entire northern hemisphere uninhabitable. All that would be necessary is for building 3 to collapse.

Anonymous said...

It is a global death warrant to continue forward with nuclear energy. This event itself still contains the potential to leave the entire northern hemisphere uninhabitable. All that would be necessary is for building 3 to collapse.

that is a bit over the top I believe and most likely NOT an Educated guess but an emotive opinion.

What really happened and what is being done to prevent this again?

Why would you have your spent fuel pools in the same building as your operating reactor? Stupid- you are asking for trouble
Why put the reactors so close to each other? Stupid.
Why have the Power Plant next to the ocean (for cooling) Stupid - it's called pumping.

Tom said...

And siting the complex in a tsunami-prone location was abysmally stupid.

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