Japan Earthquake: Nuclear Plants at Fukushima Daiichi

In summary: RCIC consists of a series of pumps, valves, and manifolds that allow coolant to be circulated around the reactor pressure vessel in the event of a loss of the main feedwater supply.In summary, the earthquake and tsunami may have caused a loss of coolant at the Fukushima Daiichi NPP, which could lead to a meltdown. The system for cooling the reactor core is designed to kick in in the event of a loss of feedwater, and fortunately this appears not to have happened yet.
  • #1,016
TCups said:
...

Hint
the arrow on top of the drawing indicate "sea" 海 in japanse
so you got it the wrong way round
 
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  • #1,017
TCups said:
Fred: From the annotations that are in the English alphabet, that would be my guess, too - T/B = Turbine Bldg D/G = Diesel Generator, maybe. But the scale doesn't fit, unless it is only part of the building plan. The structure circled in the lower right of the floor plan, as usual, caught my eye. I was wondering if it might have something to do with the hole in the roof of Bldg 3. Probably not.

The orientation of the floorplan is reversed, I believe, in the overlay photo you attached. There's an arrow with the character for "sea" pointing up. I don't read Japanese but I do know quite a bit of Chinese and there are a lot of the same characters used.
 
  • #1,018
My instinct just tells me that the circle at the bottom of the drawing could represent the torus of the reactor n°3.

Some drawings also can confirm what my instinct tells me:

Typical BWR Mark I
http://www.netimago.com/image_181784.html

Oyster Creek reactor (US):
To help understand the scale of what we are talking about with these reactors, just consider the relative size of item n°32 on this sketch, which is the entrance gate for personnel and tools inside the containment vessel
http://www.netimago.com/image_181785.html
An other picture that give a good idea of the size of these litlle nuclear cookers:

http://www.netimago.com/image_181791.html

(I'm not sure if this represents the steel confinement or the concrete around it). On this picture, the round hole above the torus is maybe the gate of item 32 (it seems to be around 4,5 meters diameter based on the size of guy on the left side).
 
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  • #1,019
REGARDING UNIT 3

As referenced above from this document:
http://www.grs.de/sites/default/files/UE-STC-Stand_1100_240311_0.pdf

and quoting, in part, from page 10 of the document:

"From 11:03 h until 13:20 h on 23-03-2011, 35 t of sea water were pumped into the fuel pool of Unit 3 via the pool cooling and purification system.

At 16:20 h (23-03-2011), black smoke emanated from the reactor building of Unit 3. Subsequently, the surrounding premises of Units 3 and 4 were evacuated as a precau- tion. However, the measured values of the reactor pressure vessel and of the contain- ment as well as radiation measurements by the measuring probes in the direct vicinity of the plant showed no significant changes.

The smoke development seemed to cease on 24-03-2011 at around 4:50 h.
At 5:35 h, sea water injection into the fuel pool via the pool water and purification sys- tem was resumed.


According to JAIF (24-03-2011, 10:00 h), the containment is not damaged. Sea water injection into the reactor pressure vessel is being continued.

INES classification by the authority
The event in Unit 3 was classified by the authority on 18-03-2011 as INES 5."


Emphasis added is my own.

Does "containment is not damaged" refer to the reactor vessel and primary containment, or the reactor vessel only, or the primary (dry wall) containment only? I wish the statement had been more precise.

I can see only 2 sources of high level radiation contamination that might come from Unit 3 -- the reactor core or the spent fuel pool (or both). If either the RV or the RV and the primary containment are intact, then could vented steam from Unit 3 RV account for the high level contamination on the ground? If not, then it seems it must have come from the SFP.

Is there any other conclusion that would explain the highest measured levels contamination on the ground (if that is the appropriate term to use) other than it coming from either the core or SFP? Perhaps water leakage from the water sprayed on the building?

Is the most likely (even if speculative) conclusion that there has been both damage to and scattering of at least part of the fuel rod contents of the SFP at Unit 3? I cannot see any other.
 
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  • #1,020
[PLAIN]http://i.min.us/imry38.jpg

D/G = Diesel Generator, in line with the diesel tank.. makes sens
 
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  • #1,021
Well thank god for GRS... who are they? German?

That's such a relief to see information put so succinctly that I actually understand and believe it.!
Finally sounds like they're getting to grips with the whole thing now, with actual coolant flowrates and sensible temperature readings.

time to chill a little!
 
  • #1,022
|Fred said:
Hint
the arrow on top of the drawing indicate "sea" 海 in japanse
so you got it the wrong way round

Thanks all for corrections. My Japanese is even worse than my French.

Corrected diagram of Steam Turbine Bldg 3 oriented to satellite photo (maybe).
 

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  • #1,023
|Fred said:
[PLAIN]http://i.min.us/imry38.jpg

D/G = Diesel Generator, in line with the diesel tank.. makes sens

This nice insertion of the drawing makes sense to me also...
 
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  • #1,024
jlduh said:
This nice insertion of the drawing makes sense to me also...

I am usually facile enough with images. It is the assessment of the additional data on radiation, and the actual design and operation of the BWR's where I am usually on shaky ground (excuse the quake reference).

Notice that in this diagram, if you look closely, there is a brave fellow in a white lab coat standing in the cutaway of the torus pool, which will give a good size reference.

DrywellTorus.jpg


Just for fun, I put his "clone" in the SFP. Wonder what his badge would read now.
 

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  • #1,025
jlduh said:
My instinct just tells me that the circle at the bottom of the drawing could represent the torus of the reactor n°3.

Some drawings also can confirm what my instinct tells me:

Typical BWR Mark I
http://www.netimago.com/image_181784.html

Oyster Creek reactor (US):
To help understand the scale of what we are talking about with these reactors, just consider the relative size of item n°32 on this sketch, which is the entrance gate for personnel and tools inside the containment vessel
http://www.netimago.com/image_181785.html



An other picture that give a good idea of the size of these litlle nuclear cookers:

http://www.netimago.com/image_181791.html

(I'm not sure if this represents the steel confinement or the concrete around it). On this picture, the round hole above the torus is maybe the gate of item 32 (it seems to be around 4,5 meters diameter based on the size of guy on the left side).

Shown (light bulb) is the inner steel liner of Primary Containment Structure (cement) that surrounds the Reactor Vessel.
 
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  • #1,026
Breaking TCups news..
we are probably going to get answers (and likely more question) once I translated this:

News 3号機のプール温度 31度に Temperature Of the Unit 3 Pool 31° WTF ?
translating asap

edit:
According to a survey held the morning of the 24th by Self-Defense Force helicopter, the surface temperature of Fukushima Daiichi Nuclear Power Station spent fuel pool at Unit 3, dropped to 31 degrees.
The surface temperature of the building No. 4 to No. 1 T, droped 23° or was bellow 23° (not sure)
 
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  • #1,027
Thanks Reno Deano for the confirmation, i thought it was steel but the appearance of the joints between the different part were strange to me like if it was joints between concrete parts. I imagine that due to its huge size this vessel is built on site like for a boat (welded on site)?
 
  • #1,028
|Fred said:
Breaking TCups news..
we are probably going to get answers (and likely more question) once I translated this:

News 3号機のプール温度 31度に Temperature Of the Unit 3 Pool 31° WTF ?
translating asap

edit:
According to a survey held the morning of the 24th by Self-Defense Force helicopter, the surface temperature of Fukushima Daiichi Nuclear Power Station spent fuel pool at Unit 3, dropped to 31 degrees.
The surface temperature of the building No. 4 to No. 1 T, droped 23° or was bellow 23° (not sure)

News Flash for Fred:

That tells us about what may be left in the SFP, but not necessarily what is no longer present in the SFP.
 
  • #1,029
artax said:
can someone please explain what is producing this so called neutron ray that's been seen (sorry detected)? There was the mention of 1.5km, so I can only assume that it's been detected 1.5km distance from the plant, in a certain direction?

I think there is a problem with translation from Japanese to English. The Neutron "Ray" is probably the detection of a stray neutron. Many particles that decay radioactively spit out neutrons. It happens normally with radioactive particles in our rocks and soil, but is only infrequently detected unless you are in a Uranium mine.

Picking up a stray neutron is no big deal. Picking up many neutrons outside of the plant implies that delayed neutron precursors have been released to the outside of the plant or that Uranium or Plutonium from the fuel rods is present.

The additional information that we need to know is what is the strength of the ray? If it is just one neutron, we have almost nothing to worry about. Many neutrons and we have trouble.
 
  • #1,030
TCups said:
News Flash for Fred:

That tells us about what may be left in the SFP, but not necessarily what is no longer present in the SFP.

That is exactly what I thought. How did the Japanese get the reactor fuel plates to stop heating up?
 
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  • #1,031
Joe Neubarth said:
That is exactly what I thought. How did the Japanese get the reactor core to stop heating up the primary. It is too soon after shut down last week for it not to be heating the water and the vessel that contains that water. So the question that comes to mind is where is the core?
If it is underground, we have lots of trouble on our hands.


Sorry, but they are discussing the temperature of the pool and not of the reactor no ?

the drop of the temperature of the spent fuell pool, i guess, could not lead to the conclusion that the core is gone undergroud, isn't it ?
 
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  • #1,032
havemercy said:
Sorry, but they are discussing the temperature of the pool and not of the reactor no ?

the drop of the temperature of the spent fuell pool, i guess, could not lead to the conclusion that the core is gone undergroud, isn't it ?

I will "guess" here, but it will be an educated guess. If the survey were done by a helicopter, then they might be using a laser interferometer and it would indeed measure the surface temperature of what it were shined on, in this case, the surface of the exposed SFP of unit 3. This would say nothing about 1) how deep the water is in the pool, or 2) if there were still fuel rods in the pool, or if there were still fuel rods in the pool, how many were still there. Also, Fred's "news fragment" doesn't indicate degrees in Fahrenheit or Celsius. I would hazard to "guess" degrees Celcius (ºC).

If they are all still there, then a temp reading of 23ºC is fantastic news. If all of the fissionable material has been blown out of the pool and (speculating wildly here) lies out and about on the ground or atop the building ruins, "beaming" neutrons and scattering gamma radiation, then there would be no reason for the pool to heat up. The real answer could be either or anything between those two ends of the possibility spectrum. Who knows.
 
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  • #1,033
Joe Neubarth said:
I think there is a problem with translation from Japanese to English. The Neutron "Ray" is probably the detection of a stray neutron. Many particles that decay radioactively spit out neutrons. It happens normally with radioactive particles in our rocks and soil, but is only infrequently detected unless you are in a Uranium mine.

Picking up a stray neutron is no big deal. Picking up many neutrons outside of the plant implies that delayed neutron precursors have been released to the outside of the plant or that Uranium or Plutonium from the fuel rods is present.

The additional information that we need to know is what is the strength of the ray? If it is just one neutron, we have almost nothing to worry about. Many neutrons and we have trouble.

Here is what I had asked earlier re: the Neutron ray, as well as a person's excerpt of the press item describing said neutron ray- that also inquired above me (page 58 near the bottom) My knowledge of nuclear physics is rudimentary, but wouldn't neutron rays captured 1.5 km away, even such low readings, lead one to extrapolate that fissable material escaped the Suppression pools, and perhaps even containment?

From Reuters: "Radiation at the crippled Fukushima No.2 nuclear reactor was recorded at the highest level since the start of the crisis, Japan's nuclear safety agency said on Wednesday. An agency spokesman said 500 millisieverts per hour of radiation was measured at the No.2 unit on Wednesday. Engineers have been trying to fix the plant's cooling system after restoring lighting on Tuesday."

from Kyodo:

Electric Power Co. said Wednesday it has observed a neutron beam, a kind of radioactive ray, 13 times on the premises of the Fukushima Daiichi nuclear plant after it was crippled by the massive March 11 quake-tsunami disaster.

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant's No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level.

Not trying to flame the fire here. The rad levels are low and I'm hoping TEPCO continues to make progress controling the site but the neutron beam got me thinking about reactor integrity. Neutron beams are product of fission correct? Would this finding confirm reactor damage even if it's just a pin hole?

Y, 11:28 AM #928
KateB

KateB is Offline:
Posts: 1
Re: Japan Earthquake: nuclear plants
I was actually just going to query on the neutron beam reported 1.5 km from the Fukushima nuclear plant. As a Biochem undergrad, my knowledge of physics is rudimentary at best, but wouldn't a neutron beam offsite signify release of plutonium/uranium, and to extrapolate further, does this mean that one of the spent fuel pools blew fissable material "sky-high"? What are the implications of this news? I have been following this thread for a while, and this has been a great pool of knowledge and learning for me.
 
  • #1,034
I thought that emphasized strongly enough my surprise , rather than my joy.

Tepco had this information since this morning... and it was only released at 21:15
it is 2:45 am ... and we are still waiting for tepco press conference that has been delayed ... ( am I losing my science? )

NB: Japanese do not use barbaric units.. they use celcius :eek:)
Ps: They says that the temperature mesured on the 23th was 57°
 
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  • #1,035
|Fred said:
I thought that emphasized strongly enough my surprise , rather than my joy.. hence my hint that this would raise more questions...

Tepco had this information since this morning... and it was only released at 21:15
it is 2:45 am ... and we are still waiting for tepco press conference that has been delayed ... ( am I losing my science? )

NB: Japanese do not use barbaric units.. they use celcius :eek:)

No, Fred -- keep us informed. Thanks.
 
  • #1,036
At the bottom of this article from today..

http://english.kyodonews.jp/news/2011/03/80849.html

"The government said, meanwhile, it detected 2.54 million becquerels of iodine and 2.65 million becquerels of cesium, another radioactive substance, from weed leaves in the village of Iitate in Fukushima Prefecture about 40 km northwest from the nuclear plant, far above the provisional limits for food of 2,000 becquerels for iodine and 500 becquerels for cesium.

Abnormally high levels of these materials were also detected again in the sea near the plant, TEPCO said, warning the radiation levels in seawater may keep rising."

So...evac zone is 20km...these levels were detected 40km away, yet they are only 'considering' increasing the evac zone for convenience. Am I just misunderstanding the amounts quoted, they seem significant.

Thanks everyone for the information here, I have been quietly absorbing it.
 
  • #1,037
TCups said:
Corrected diagram of Steam Turbine Bldg 3 oriented to satellite photo (maybe).

the turbine building 3 is about 125 x 35 metres
the reactor building 3 is about 45 x 34 metres
reactor building to turbine building is about 25 metres apart
(source measured on google Earth 35:25:15N 141:02:02E)

Turbine building has an aspect ratio of 3:1Japanese plan has an aspect ratio of 2:1
I estimate it at 120 by 60 metres (based on door sizes, corridors)
Has no doors to the outside, so it is either a basement or an upper floor,
My guess upper floor as a ladies and gents can be identified. (just above the ng of Turbine Building)

My next guess - upperfloor of turbine building + connecting building between reactor and turbine
attachment.php?attachmentid=33479&stc=1&d=1300991084.jpg
 

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  • #1,038
Hi guys, 1st post!

Fascinating, terrifying stuff in this thread..

Here is a report by the US Department of Energy on blackout (no power supply) conditions in a Mark.1 G.E. BWR.

Note the timeline below:

Ru11l.jpg



Here is the full report.

http://www.osti.gov/bridge/servlets/purl/6124656-R8y05j/6124656.pdf

It states that all reactors should have ruptured their boilers within 8 hours.

Can we *really* have corium below ground? Where is the water table?
 
  • #1,039
AntonL said:
the turbine building 3 is about 125 x 35 metres
the reactor building 3 is about 45 x 34 metres
reactor building to turbine building is about 25 metres apart
(source measured on google Earth 35:25:15N 141:02:02E)

Turbine building has an aspect ratio of 3:1Japanese plan has an aspect ratio of 2:1
I estimate it at 120 by 60 metres (based on door sizes, corridors)
Has no doors to the outside, so it is either a basement or an upper floor,
My guess upper floor as a ladies and gents can be identified. (just above the ng of Turbine Building)

My next guess - upperfloor of turbine building + connecting building between reactor and turbine
attachment.php?attachmentid=33479&stc=1&d=1300991084.jpg

So all the diesel generators were on the ground floor? I have read that the diesel generators were washed away. So what was the extent of the damage to the main Turbine Generator? I am guessing that is what was in the middle of the schematic?
 
  • #1,040
Joe Neubarth said:
So all the diesel generators were on the ground floor? I have read that the diesel generators were washed away.

They were not. They started to work as expected and failed after about an hour.
 
  • #1,041
tepco conference just finished at 5 am !... ****
 
  • #1,042
Bodge said:
It states that all reactors should have ruptured their boilers within 8 hours.

If memory serves me well, cooling systems were working for about 9 hours - first on DG, then on batteries. I don't know how fast heat output from decay goes down, but for sure it is the strongest during first hours after scramming.
 
  • #1,043
Borek said:
If memory serves me well, cooling systems were working for about 9 hours - first on DG, then on batteries. I don't know how fast heat output from decay goes down, but for sure it is the strongest during first hours after scramming.

Thanks Borek

Decay_heat_illustration.PNG


Still worrisome though
 
  • #1,044
Japanese are considering upgrading to INES 6, very confusing they were talking about radiation in terms of 27 Ci in the water on the power plant.
I'll wait for the official bulletin..

edit: mainly the press conference was minor statement from tepco indicating that, the worker went to a zone that was supose to have minor "air" radiation,when they arrived they found 13 cm of water , 2 of them where not prepare for that and did not have boots, (those 13 cm of water were not present the day before)
the radiation was in the range of 400mSv/h .
The press asked a lot of questions as for where does the watter come from etc.. Tepco does not know , one hypothesis that they are considering is a total meltdown of the rods (Spent Fuel ?) ..

we will get a better view tomorrow
 
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  • #1,045
KateB said:
Here is what I had asked earlier re: the Neutron ray, as well as a person's excerpt of the press item describing said neutron ray- that also inquired above me (page 58 near the bottom) My knowledge of nuclear physics is rudimentary, but wouldn't neutron rays captured 1.5 km away, even such low readings, lead one to extrapolate that fissable material escaped the Suppression pools, and perhaps even containment?

From Reuters: "Radiation at the crippled Fukushima No.2 nuclear reactor was recorded at the highest level since the start of the crisis, Japan's nuclear safety agency said on Wednesday. An agency spokesman said 500 millisieverts per hour of radiation was measured at the No.2 unit on Wednesday. Engineers have been trying to fix the plant's cooling system after restoring lighting on Tuesday."

from Kyodo:

Electric Power Co. said Wednesday it has observed a neutron beam, a kind of radioactive ray, 13 times on the premises of the Fukushima Daiichi nuclear plant after it was crippled by the massive March 11 quake-tsunami disaster.

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant's No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level.

Not trying to flame the fire here. The rad levels are low and I'm hoping TEPCO continues to make progress controling the site but the neutron beam got me thinking about reactor integrity. Neutron beams are product of fission correct? Would this finding confirm reactor damage even if it's just a pin hole?

Y, 11:28 AM #928
KateB

KateB is Offline:
Posts: 1
Re: Japan Earthquake: nuclear plants
I was actually just going to query on the neutron beam reported 1.5 km from the Fukushima nuclear plant. As a Biochem undergrad, my knowledge of physics is rudimentary at best, but wouldn't a neutron beam offsite signify release of plutonium/uranium, and to extrapolate further, does this mean that one of the spent fuel pools blew fissable material "sky-high"? What are the implications of this news? I have been following this thread for a while, and this has been a great pool of knowledge and learning for me.

From post #22 https://www.physicsforums.com/showthread.php?t=481620

Re: Astronuc

"The matter of the neutron 'beam' or neutron radiation is of concern. It would seem to indicate loss of transuranics (fuel particles/fines) from the containment, which is not a good sign.
__________________
Getting the 'right' answer is important, but understanding how to solve the problem (i.e. how you get the right answer) is just as important, if not more so.
Peace on Earth, and Goodwill to all Peoples, each day, every day, ad infinitum. - Joy to the World, Joy to You and Me. - Three Dog Night

The other 2005 Engineering Gurus: FredGarvin, Clausius2, Brewnog, Morbius, PerennialII, berkeman, arildno, Cliff_J, Geniere, minger

Raspberry Jam Delta-V - Joe Satriani"
 
  • #1,046
M. Bachmeier said:
From post #22 https://www.physicsforums.com/showthread.php?t=481620

Re: Astronuc

"The matter of the neutron 'beam' or neutron radiation is of concern. It would seem to indicate loss of transuranics (fuel particles/fines) from the containment, which is not a good sign.
__________________
Getting the 'right' answer is important, but understanding how to solve the problem (i.e. how you get the right answer) is just as important, if not more so.
Peace on Earth, and Goodwill to all Peoples, each day, every day, ad infinitum. - Joy to the World, Joy to You and Me. - Three Dog Night

The other 2005 Engineering Gurus: FredGarvin, Clausius2, Brewnog, Morbius, PerennialII, berkeman, arildno, Cliff_J, Geniere, minger

Raspberry Jam Delta-V - Joe Satriani"

Thank you. That is what I was concerned about. I appreciate the reply, It didn't occur to me to check other threads. I know speculation is not encouraged here, but perhaps someone could posit an educated guess as to the implications of transuranics escaping containment, and most especially if they had come from the Hydrogen explosion at No. 3 that rendered the building? I realize this hinders the effort at containment, but my question centers more on what the best and worst outcome regarding the possible escape of these particles could mean, mostly in the long term, as I know the half lives of these isotopes can range from multiple thousand to billions of years. I remember hearing a scientist say that the "fallout" from an atomic bomb was "safer" (which I realize is a ludicrous word to use in any discussion on large radioactive releases and/or bombs) than the slow fission and continued presence of transuranics within the environment. Is there a plausible way to recover any of these materials from the environment, IF there is indeed any release, or will an extended area have to be abandoned for...an eternity in human foresight? Thanks in advance.
 
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  • #1,047
|Fred said:
tepco conference just finished at 5 am !... ****

Anything to report?
 
  • #1,048
Borek said:
They were not. They started to work as expected and failed after about an hour.

They failed about thirty minutes after the Earthquake (and reactor Scram) because they no longer were there.
 
  • #1,049
M. Bachmeier said:
__________________
Getting the 'right' answer is important, but understanding how to solve the problem (i.e. how you get the right answer) is just as important, if not more so.
Peace on Earth, and Goodwill to all Peoples, each day, every day, ad infinitum. - Joy to the World, Joy to You and Me. - Three Dog Night

The other 2005 Engineering Gurus: FredGarvin, Clausius2, Brewnog, Morbius, PerennialII, berkeman, arildno, Cliff_J, Geniere, minger

Raspberry Jam Delta-V - Joe Satriani"

With ruptured fuel plates, a release of high pressure steam would carry some entrained solids with it. The question is how much?
 
  • #1,050
TCups said:
News Flash for Fred:

That tells us about what may be left in the SFP, but not necessarily what is no longer present in the SFP.

The fact that they can get into the plants and grounds around them indicate that there are no spent fuel rods from the SFPs laying about.
 

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