Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[AntonL]

Regarding the MOX fuel, I doubt that there is any in the SFP of reactor 3.

Thus any Pu measurements indicate a leakage from unit 3 reactor is this a correct assumption?

Third Japanese reactor to load MOX
10 August 2010
Tokyo Electric Power Company's (Tepco's) Fukushima I unit 3 is set to become the third Japanese nuclear reactor to load mixed oxide (MOX) fuel after receiving approval from the governor of Fukushima Prefecture, Yukei Sato. The unit follows Kyushu Electric's Genkai 3, which started using MOX fuel in November 2009, and Shikoku's Ikata 3, which was loaded with some MOX fuel in March 2010. According to the Denki Shimbun, the 760 MWe boiling water reactor will be loaded with MOX fuel by 21 August and the unit will restart in late September. Japan's Nuclear and Industrial Safety Agency has so far approved the use of MOX fuel in ten reactors, but utilities must also secure approval from prefectural governments before they can go ahead and use the fuel, which contains plutonium recovered from spent nuclear fuel.

 

[ailog]

I have followed this thread and the situation in Japan but am uncertain of what's happening currently. Here are some GENERAL observations and some questions. Please comment to help my understanding.

1. There is presently no coolant circulation whatsoever in any of the reactors 1 thru 4? The rush to get electrical power back on was to no avail because coolant pumps/piping and electrical equipment and controls were damaged beyond repair. Which means that if the emerg. generators had survived they most probably wouldn't have mattered (wrt circulating coolant).

2. Currently the affected reactors are filled with seawater? If the seawater is not circulated and cooled somehow, how does this help the reactor core? Just distributes the core heat? Steam is being made and periodically vented to reduce pressure?

3. If boron is a good moderator, would pumping a slurry of boron into the reactors help?

 

[M. Bachmeier]

Has anyone looked at the potential leaks from the mounts of the dry-well caps 1-3?

I'm sure I've come across more than one reference to effective seating of the cap on older Mark I reactors.

Without guile, is this the primary leak of contaminants?

 

[Joe Neubarth]

I have followed this thread and the situation in Japan but am uncertain of what's happening currently. Here are some GENERAL observations and some questions. Please comment to help my understanding.

1. There is presently no coolant circulation whatsoever in any of the reactors 1 thru 4? The rush to get electrical power back on was to no avail because coolant pumps/piping and electrical equipment and controls were damaged beyond repair. Which means that if the emerg. generators had survived they most probably wouldn't have mattered (wrt circulating coolant).

2. Currently the affected reactors are filled with seawater? If the seawater is not circulated and cooled somehow, how does this help the reactor core? Just distributes the core heat? Steam is being made and periodically vented to reduce pressure?

3. If boron is a good moderator, would pumping a slurry of boron into the reactors help?

1.Once cool enough a massive quantity of water can keep the Reactor Fuel from heating up. The question is where is it?

2. Pressure?

3. Until we find out where the fuel is, Boron in ample quantities to meet water standards is necessary. The control rods with most of the boron in them may still be standing tall. Just because the Zirconium and the Uranium flowed down to the bottom of the reactor does not mean the Control rods did. If they did melt in conjunction with the reactor melt down, the Boron would have dissolved in solution. As they were pumping sea water in by the ton, they probably seriously diluted the amount of boron in the reactor even though they are said to have injected boron at the end of the sea water injection. The sea water injection by itself could have led to limited criticality and reheating of the forming Uranium Lava sufficiently to burn through the bottom of the reactor vessel. I suspect that they made a bad situation far worse. Now that the water has accumulated in many diverse places it has a dilute solution of boron in it, but we do not know for certain where the Uranium fuel is.

 

[razzz]

Press Release (Mar 29,2011)
Plant Status of Fukushima Daini Nuclear Power Station (as of 9:00 am March 29th)[No update from the last release issued at 9:00 pm, March 28th]

Unit Status
1 · Reactor cold shutdown, stable water level, offsite power is
available.
· No reactor coolant is leaked to the reactor containment vessel.
· Maintain average water temperature below 100°C in the Pressure
Suppression Chamber.
2 · Reactor cold shutdown, stable water level, offsite power is
available.
· No reactor coolant is leaked to the reactor containment vessel.
· Maintain average water temperature below 100°C in the Pressure
Suppression Chamber.
3 · Reactor cold shutdown, stable water level, offsite power is
available.
· No reactor coolant is leaked to the reactor containment vessel.
· Maintain average water temperature below 100°C in the Pressure
Suppression Chamber.
4 · Reactor cold shutdown, stable water level, offsite power is
available.
· No reactor coolant is leaked to the reactor containment vessel.
· Maintain average water temperature below 100°C in the Pressure
Suppression Chamber.
Other N.A.

...Have a nice day...

 

[AntonL]

IAEA presentations available here http://www.slideshare.net/iaea/

 

[AntonL]

@AtomicWombat

I stand corrected, sir. The detail picture originally provided as a screenshot and then annotated by me to show what I thought was the shaft, SFP, and something in the SFP is apparently WRONG. The screenshot I annotated matches the north end of the floor of Bldg 3, not the south end, so it cannot be as I annotated it. Sorry for the error. () The pool shown would have to be the equipment pool, not the SFP. I don't know if the equipment pool has a transfer chute and gate.

Post #1760 has been edited with the correction and the annotated photo I first posted there deleted.

https://www.physicsforums.com/attachment.php?attachmentid=33668&d=1301364476

As the SFP is on the south side of the reactor, the steam escaping on the north side (follow link above) could indicate that the containment is breached and steam is not from a boiling SFP pool.

 

[AntonL]

[URL]http://www.asahi.com/national/update/0329/images/TKY201103290240.jpg[/URL]

[URL]http://www.asahi.com/national/update/0329/images/TKY201103290255.jpg[/URL]

The plan is to pump water in outside tunnel/trench into suppression water storage tanks marked by 2 blue dots south of unit 4. Total 6800m3 storage is available in those two tanks but 2800m3 are already stored - so 4000m3 can be pumped from the tunnel/trenches into those tanks.

The table list the maximum volume of the tunnel/trenches before overflowing, but we can see that they are about to overflow by the levels given.

 

[shogun338]

Has anyone looked at the potential leaks from the mounts of the dry-well caps 1-3?

I'm sure I've come across more than one reference to effective seating of the cap on older Mark I reactors.

Without guile, is this the primary leak of contaminants?

This is a good link about the seal that may be leaking a lot of this water around the area. http://allthingsnuclear.org/post/3964225685/possible-source-of-leaks-at-spent-fuel-pools-at This happened at plant Hatch in Georgia back in 1986 and they lost over 140000 gallons of water from the spent fuel pool . Don't trust TEPCO to tell the truth because when this happened at Hatch they told everyone that only 5000 gallons leaked. I live very close to Plant Hatch and fish around it all the time on the Altamaha River .

 

[shogun338]

I have followed this thread and the situation in Japan but am uncertain of what's happening currently. Here are some GENERAL observations and some questions. Please comment to help my understanding.

1. There is presently no coolant circulation whatsoever in any of the reactors 1 thru 4? The rush to get electrical power back on was to no avail because coolant pumps/piping and electrical equipment and controls were damaged beyond repair. Which means that if the emerg. generators had survived they most probably wouldn't have mattered (wrt circulating coolant).

2. Currently the affected reactors are filled with seawater? If the seawater is not circulated and cooled somehow, how does this help the reactor core? Just distributes the core heat? Steam is being made and periodically vented to reduce pressure?

3. If boron is a good moderator, would pumping a slurry of boron into the reactors help?

USA has sent boron to Japan to pump into the reactors . Other countries are also sending it to Japan . http://www.liveleak.com/view?i=d35_1300513133

 

[Soafcom]

Here are a few more images of Reactor 3 from 2011-03-16:

 

[|Fred]

This is a picture of unit 4 showing S/W wall and S/E wall
in Green overlay the operating Floor, in blue the alleged Spebt Fuel Pull
In yellow overlay the floor bellow the operating floor, notice that on this unit 4 the blast seems to have occurred on that yellow floor as well. how do we make sens of that ?

ps: http://www.ustwrap.info/show/iwakamiyasumi
tepco Press conference just started

 

[AntonL]

notice that on this unit 4 the blast seems to have occurred on that yellow floor as well. how do we make sens of that ?[/url]
tepco Press conference just started

If you check all available photos and videos you will see that the fuel loading tunnel to the west of the building is also destroyed. Unit 4 was under maintenance so fire/blast doors, hatches etc would be open that in units 1-3 would have been shut tightly allowing the blast to propagate from roof to basement as is evident in the visual material

 

[shogun338]

This is a picture of unit 4 showing S/W wall and S/E wall
in Green overlay the operating Floor, in blue the alleged Spebt Fuel Pull
In yellow overlay the floor bellow the operating floor, notice that on this unit 4 the blast seems to have occurred on that yellow floor as well. how do we make sens of that ?

ps: http://www.ustwrap.info/show/iwakamiyasumi
tepco Press conference just started

When reactor #3 exploded it caused most of this damage to unit 4 from the reports I have read . Here is a link to the very large explosion at reactor #3 . Reactor #3 is also the reactor that was loaded with the MOX fuel .http://ireport.cnn.com/docs/DOC-573617

 

[AtomicWombat]

This is a picture of unit 4 showing S/W wall and S/E wall
in Green overlay the operating Floor, in blue the alleged Spebt Fuel Pull
In yellow overlay the floor bellow the operating floor, notice that on this unit 4 the blast seems to have occurred on that yellow floor as well. how do we make sens of that ?

Hi Fred,
This is the southern wall of this reactor building. There is an almost identical hole in the northern wall (see my attachment) that has what looked to me like a discharge of corium lava. It may be just melted insulation. I am still unsure. Based on the position of the fuel crane (northern wall), it seems that this melted mass is unlikely to be corium.

I can explain the holes in the opposing sides assuming they are adjacent to the equipment pool (on one side) and the SFP on the other. Hydrogen would accumulate over the SFP. Once it reached the explosion limit the explosion would be strongest there, presumably strong enough to blow out both the SFP containment and the exterior wall.

Reactor diagrams also show that adjacent to the equipment pool the exterior wall is the only barrier to the outside environment. So this would be a weak point.

I find it difficult to explain why so many panels below the operating floor on the east and west side also blew out, especially since hydrogen is a light gas and would not tend to settle deep in the building..

 

[Emreth]

When reactor #3 exploded it caused most of this damage to unit 4 from the reports I have read . Here is a link to the very large explosion at reactor #3 . Reactor #3 is also the reactor that was loaded with the MOX fuel .http://ireport.cnn.com/docs/DOC-573617

We've been over this here, there are images after explosion at unit 3 which shows no damage on unit 4.

 

[AtomicWombat]

Unit 4 was under maintenance so fire/blast doors, hatches etc would be open that in units 1-3 would have been shut tightly allowing the blast to propagate from roof to basement as is evident in the visual material

Seriously? I had no idea these procedures were in place in reactors. It's like a warship or submarine.

 

[jensjakob]

Areva sends 2 experts to Fukushima:
http://english.kyodonews.jp/news/2011/03/81681.html

 

[shogun338]

We've been over this here, there are images after explosion at unit 3 which shows no damage on unit 4.

Why would it explode if it was in shut down mode ? Where is the link to the pics and the explosion of #4 ? I can't find them .

 

[Emreth]

Why would it explode if it was in shut down mode ? Where is the link to the pics and the explosion of #4 ? I can't find them .

This is the image after explosion #3 before #4. I don't think we have an explosion video for #4. #4 had fresh fuel in SFP.
https://www.physicsforums.com/showpost.php?p=3197547&postcount=539

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg

 

[|Fred]

When reactor #3 exploded it caused most of this damage to unit 4 from the reports I have read

Please stand corrected, as this statement is not true. see attachment.

This is the southern wall of this reactor building. There is an almost identical hole in the northern wall

Thank you, notice that this hole is located on the floor below the operating floor and notice the way and that the wall still standing on the North on the operating floor.

What doe not make sens to me is that the pool are open to the air and located south.
assuming the watter level droped the hydrogen would have populated the operating floor going up from the pool rather than seeking ways across concrete , if anything it could have some how populated the top of the reactor core vessel.

But the floor bellow the operating floor makes little if no sens ? is there a structure that runs bellow the OP floor North to South on the whole level and is connected to the pool?

 

[shogun338]

This is the image after explosion #3 before #4. I don't think we have an explosion video for #4. #4 had fresh fuel in SFP.
https://www.physicsforums.com/showpost.php?p=3197547&postcount=539

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg

Thanks for the pics. I see what your saying now . So just the spent fuel pools leaking most of the water out causes hydrogen to build up in the buildings causing them to explode .

 

[Borek]

What i think is even if there is a catastrophic radiactivity, it will be held confidential for various reasons.

You can buy a radiometer for something like $300 and check the radiation level by yourself, no way contamination can be held confidential.

 

[TCups]

Please stand corrected, as this statement is not true. see attachment.

But the floor bellow the operating floor makes little if no sens ? is there a structure that runs bellow the OP floor North to South on the whole level and is connected to the pool?

Fred:
The link between the open holes on the north and south walls of Unit 4, one level below the top floor, would seem to be the open tops of the SFP on the south and the equipment pool on the north. A blast in the top floor would, transmit a hydraulic shock wave into the pools if they were full of water. If not full of water, then they would be directly connected by air space and still subject to direct damage from the blast.

Consider, though, that if there were still some water in the equipment pool on the north end of Bldg 4, and if the damage were from hydraulic transmission of the shock wave, then that "tongue" of material we initially saw hanging out, whatever it was, may have been carried out by the water that gushed out.

 

[TCups]

Hi Fred,
This is the southern wall of this reactor building. There is an almost identical hole in the northern wall (see my attachment) that has what looked to me like a discharge of corium lava. It may be just melted insulation. I am still unsure. Based on the position of the fuel crane (northern wall), it seems that this melted mass is unlikely to be corium.

I can explain the holes in the opposing sides assuming they are adjacent to the equipment pool (on one side) and the SFP on the other. Hydrogen would accumulate over the SFP. Once it reached the explosion limit the explosion would be strongest there, presumably strong enough to blow out both the SFP containment and the exterior wall.

Reactor diagrams also show that adjacent to the equipment pool the exterior wall is the only barrier to the outside environment. So this would be a weak point.

I find it difficult to explain why so many panels below the operating floor on the east and west side also blew out, especially since hydrogen is a light gas and would not tend to settle deep in the building..

AW:

The picture you attached:
https://www.physicsforums.com/attachment.php?attachmentid=33678&d=1301381377

ls the north wall, and the outward "flow" appearance may be the result of water that gushed through the hole after the blast.

Two things about this picture have always seemed incongruent, though.

1) if the damage to bldg 4 were from an internal blast strong enough to blow that side panel out, then why the heck does the top wall seem to fall inward, not outward?!

2) look at the full length of the vertical column on the NE corner. It is damaged and appears to me to have buckled inward from the concussion of the blast at Bldg 3, doesn't it?

Another question: why don't we have video of the blast at Bldg 4? Did it occur after dark?

Something strange happened at Bldg 4, and we don't have all he information.

 

[AntonL]

1) if the damage to bldg 4 were from an internal blast strong enough to blow that side panel out, then why the heck does the top wall seem to fall inward, not outward?!

Another question: why don't we have video od the blast at Bldg 4? Did it occur after dark?

To 1) I can only think that a hydrogen blast is followed by an implosion as all the air that has been displaced gushes back into the vacuum created. Maybe someone will want to correct me on this. Thus depending on the blast dynamics the north wall could have been sucked back into the building.

Also a lot of the blast energy went down the building, as unit was under maintenance and blast/fire doors hatches etc would be open, have a look at the panels of the fuel service tunnel to the west of the building, all the panels where dislodged there at ground level

Bldg 4 explode around 6 in the morning - no helicopters in the sky circling and filming

 

[TCups]

To 1) I can only think that a hydrogen blast is followed by an implosion as all the air that has been displaced gushes back into the vacuum created. Maybe someone will want to correct me on this. Thus depending on the blast dynamics the north wall could have been sucked back into the building.

Bldg 4 explode around 6 in the morning - no helicopters in the sky circling and filming

The video of the blasts at 2, 3 were from the ground. More likely, things were starting to get "hot" and the camera crews were evacuated.

How the hell does the blast blow out all the east side panels at ground level, and yet, leave the north side panels at the same corner intact? It makes no sense.

I would love to get my hands on a full set of structural drawings of those buildings.

The only explanation I can put forth is a scary one --

1) the overhead crane protected the top north wall from the brunt of the blast force.
2) the explosion was more than hydrogen gas. It occurred in the spent fuel pool, and breeched not only the outside wall of the SFP, but also its inside wall and floor, with a large portion of the blast venting to the lower levels of Bldg 4.

The scary implication of this hypothesis is that the fuel in the SFP of Unit 3 melted "down" into the building or was blown down into the lower building when the hydrogen blast occurred. Nasty.

 

[AntonL]

Also a lot of the blast energy went down the building, as unit was under maintenance and blast/fire doors hatches etc would be open, have a look at the panels of the fuel service tunnel to the west of the building, all the panels where dislodged there at ground level

And what caused the welds on these pipes to break and unfurl? (https://www.physicsforums.com/showthread.php?p=3198789&highlight=pipes#post3198789") as arrowed and you can see fuel service tunnel panels been blown out to the right of the arrow

received no answers to #589 yet

 

[TCups]

And what caused the welds on these pipes to break and unfurl? (https://www.physicsforums.com/showthread.php?p=3198789&highlight=pipes#post3198789") as arrowed and you can see fuel service tunnel panels been blown out to the right of the arrow

received no answers to #589 yet

Uhhhhh. . . How about something very hot blasting out of that big hole? At the very least, the concrete and steel lining the wall of the SFP blew outward.

Also, the tunnel is connected to the top floor via an open vertical shaft for the lift of the fuel, right?

Bottom line, if the fuel in the SFP was the source that fueled the blast, then something very very bad happened to the fuel.

 

[Lefteris]

You can buy a radiometer for something like $300 and check the radiation level by yourself, no way contamination can be held confidential.

I might be a bit overreacting but I am thinking of doing that since I live in Tokyo and I am getting bombarded with different opinions concerning safety/leaving/staying.

The problem is that when I checked the internet for ordering through there, everything everywhere seems to be sold out or at extremely low stock(close to being sold out) and there was a huge variety of measuring tools, whose differences I did not understand. Things like radiation meter,dosimeter, geiger meter. So I don't know what's what.

What should someone buy to measure radiation in the environment? And if possible can anyone recommend any sites which would ship internationally?(to Japan specifically)