Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[artax]

there's some reasonable reactor workings animation here, doesn't really explain where the H2 explosions were though!
still pretty useful stuff.

http://edition.cnn.com/interactive/2011/03/world/interactive.nuclear.japan/index.html

oh, and I think you can ignore the cyclical behaviour of radiation in the dose/time graph!

 

[DrDu]

It means the Tc-99m was produced within six hours prior to detection.

No, it doesn't because Tc 99m is formed in the decay of Mo 99, which has about 3 days half-life time (I ignore whether Mo 99 has some other long lived precursor). Gilles pointed that out, too, in a mail which overlapped mine. After 20 days there will still be about 0.6 % of Mo99 be left, which is enough to produce large quantities of Tc.

Edit: Seems Gilles was again faster than I :-)

 

[AntonL]

No, it doesn't because Tc 99m is formed in the decay of Mo 99, which has about 3 days half-life time (I ignore whether Mo 99 has some other long lived precursor). Gilles pointed that out, too, in a mail which overlapped mine. After 20 days there will still be about 0.6 % of Mo99 be left, which is enough to produce large quantities of Tc.

Edit: Seems Gilles was again faster than I :-)

After 20 days there will still be about 0.6 % of Mo99 be left, which is enough to produce large quantities of Tc. hey thanks for this explanation, this now clears many things in my mind

 

[artax]

Yes,me too thanks DRdu !, I haven't done much with understanding grow and decay of daughter products!

 

[Astronuc]

Hi, long time listener, first time caller. I'm currently living in Japan, pretty far from danger but concerned about the water and food becoming contaminated. I don't want to sound political but, in today's press conference the TOEPC spokesman only mentioned iodine levels (good news because of the short half life), no mention of cesium. Does anyone have an explanation for this?

Iodine is a concern because of the uptake to the thyroid gland which is pretty sensitive.

http://en.wikipedia.org/wiki/Thyroid

I'm not sure about the pancreas.

Cs would also be important to know.

The further away from Fukushima, the lower the risk of contamination. The winds (jet stream) tend to blow west to east, but there are times when they can north or south, and a little bit westward, i.e., NNW or SSW.

I would expect that the other plants, e.g., Tohoku Electric's Onagawa and Higashidori plants are monitoring activity to the north, and JAPCO's Tokai plants to the south. What do they report?

 

[liamdavis]

Correct me if I am wrong but my understanding is that pure water does not become radioactive. Rather, it emits radioactivity from material that is suspended or in solution in it. Hence the steam in the turbine, having recently been in the reactor, presents no radiological safety problem. That this is accomplished by the action of a “water polisher” employing HEPA and carbon filters in the primary (RV) coolant loop.

Where I am leading is that the polishing units in the plants may be inoperable and, if operable, may be in an environment where they cannot safely be serviced. However, the function of a water polisher could be employed outside of the plant to separate radioactive material from the water in the trench and from water they are proposing to store in tanks at a remote location on site. These tanks are described as being piped to each of the buildings for temporary water storage.

My thought is to employ one or several water polishing units to separate the non-radioactive water and dispose of it in the sea. This would lessen the difficulty caused by finite storage capacity and allow more discretionary use of water for cooling. It could later be employed in the remediation of ground water at the test wells used for sampling.

More when I have had some sleep.
liam

 

[artax]

wonder how many picrutes that bloody drone's taken, and how many have been released to the 'general public' who just don't understand these things and will panic!
I want to see more, where's that Assange bloke when you need him!

 

[artax]

Correct me if I am wrong but my understanding is that pure water does not become radioactive. Rather, it emits radioactivity from material that is suspended or in solution in it. Hence the steam in the turbine, having recently been in the reactor, presents no radiological safety problem. That this is accomplished by the action of a “water polisher” employing HEPA and carbon filters in the primary (RV) coolant loop.

Where I am leading is that the polishing units in the plants may be inoperable and, if operable, may be in an environment where they cannot safely be serviced. However, the function of a water polisher could be employed outside of the plant to separate radioactive material from the water in the trench and from water they are proposing to store in tanks at a remote location on site. These tanks are described as being piped to each of the buildings for temporary water storage.

My thought is to employ one or several water polishing units to separate the non-radioactive water and dispose of it in the sea. This would lessen the difficulty caused by finite storage capacity and allow more discretionary use of water for cooling. It could later be employed in the remediation of ground water at the test wells used for sampling.

More when I have had some sleep. liam

I'm pretty sure it's not just suspended solids that become radioactive, it's any soluble ions too which is why de ionised water is used.
However I'm pretty sure the 'polishers' will be ion exchange filters or resins and will be able to 'remove' the majority of radiation from the water.

The problem is the collection of the water after it's been pumped into the building,... beacuse like the missing fuel at chernobyl... they've no idea where it's going as there's no seals/containment anymore!

 

[jensjakob]

On the drone pictures, I can't find the "fuel rods" that was pointed out on the ground by TCups in the early image analysis.

Meaning either I can't see them, or they have been moved - meaning that someone knows what they were.

 

[TCups]

BEFORE & AFTER
(just for grins)
The before from : DigitalGlobe.com
The after from post #2009, as referenced by Fred

http://i306.photobucket.com/albums/nn270/tcups/BeforeAfter.jpg

Comments:

@Jens:
I can't place much significance to the white rods (what ever they are) detailed in the first helicopter fly by vs not seeing them well in the satellite and drone images. The speculation that they could be loose fuel rods ejected from SFP3 has not been substantiated.

@Astronuc:
Thanks for confirmation - two tiers of concrete columns frame the reactor access floor at the top of Bldg 3, 4. Damage to the SFP4 below the level of the reactor access floor (ie, out the side or bottom of SFP4) and into the lower levels of Bldg 4 might be one explanation to the apparent intensity of the explosion in the lower floors. As has been suggested by another poster (JoeN?), in a cold shutdown with fuel removed, a lot of heavy doors otherwise closed during operation may have been left open.

 

[rasherz]

Iodine is a concern because of the uptake to the thyroid gland which is pretty sensitive.

http://en.wikipedia.org/wiki/Thyroid

I'm not sure about the pancreas.

Cs would also be important to know.

The further away from Fukushima, the lower the risk of contamination. The winds (jet stream) tend to blow west to east, but there are times when they can north or south, and a little bit westward, i.e., NNW or SSW.

I would expect that the other plants, e.g., Tohoku Electric's Onagawa and Higashidori plants are monitoring activity to the north, and JAPCO's Tokai plants to the south. What do they report?

I'm living NNW from the plant, but still in a safe area, way up North. It's not really a short-term concern for me. My worries are that most food processing occurs in the industrial heartland of Japan, near Tokyo. The nearby prefectures supply most of the domestically grown food for these products. Without accurate levels of Cs being made available I feel like we're being (lied to) held back from information that might be important when grocery shopping. Perhaps I'm overreacting, but Topec has a history of doing this.

 

[Astronuc]

Correct me if I am wrong but my understanding is that pure water does not become radioactive. Rather, it emits radioactivity from material that is suspended or in solution in it. Hence the steam in the turbine, having recently been in the reactor, presents no radiological safety problem. That this is accomplished by the action of a “water polisher” employing HEPA and carbon filters in the primary (RV) coolant loop.

Where I am leading is that the polishing units in the plants may be inoperable and, if operable, may be in an environment where they cannot safely be serviced. However, the function of a water polisher could be employed outside of the plant to separate radioactive material from the water in the trench and from water they are proposing to store in tanks at a remote location on site. These tanks are described as being piped to each of the buildings for temporary water storage.

My thought is to employ one or several water polishing units to separate the non-radioactive water and dispose of it in the sea. This would lessen the difficulty caused by finite storage capacity and allow more discretionary use of water for cooling. It could later be employed in the remediation of ground water at the test wells used for sampling.

More when I have had some sleep.
liam

Actually, the hydrogen in the water can absorb a neutron and become deuterium, and some deuterium can absorb a neutron and become tritium. Leaking (cracked) control blades also release some tritium.

There are filters (resin beds, not HEPA filters) in the reactor water and feedwater clean up systems. Without power to the feedwater pumps and recirculation systems, which may be damaged (if the drywell is flooded then the recirculation pumps are underwater (seawater)), then I would expect that the filtering is not working - at least not properly or efficiently if at all.

 

[TCups]

Two panels sit above the reactor service floor according to https://www.physicsforums.com/showpost.php?p=3193009&postcount=305 (AtomicWombat, page 20, post #305). See also the ridge at the bottom of the two panels.

See also images:

Tcups, page 21, #330
various on page 23
jinxdone, page 24, #381
Tcups, page 29, #463

The third set of panels sit below the ridge and below the reactor service floor. A blast out at the third level could mean damage to the SFP.

@Astronuc:

SOUTH FACE BLDG 4

See image:
http://i306.photobucket.com/albums/nn270/tcups/SouthUnit4.png

With reference to the visible external ridge on Bldg's 1-4 at the level of the reactor access floor, part of that ridge is clearly visible on this image of the south face, Bldg 4. With that as a reference point, it seems to me that the visible damage below that ridge may extend two floors below the ridge (?), and that the depth of the damage below the ridge would be consistent with the depth of the SFP4. Again, not confirmed, but perhaps suggested by the images.

Is there a separate pool (new fuel?) to the west of the larger SFP, and are the intact walls below the ridge at the SE corner indicative of an intact exterior at the level of SFP4?

 

[artax]

Nice. If those service tunnels are on the same end as the SFPs, then all 4 units, 1-4 have the SFPs on the south side of the building and the equipment storage pool is on the north. The fuel handling machines would have been parked at the south end of the spent fuel pools, and unit 4s refueling could have been over the SFP. If there was fuel debris from SFP, it then should be coming out the south face of the buildings.

Interesting as the stuff at 55 seconds on this (re uploaded vid) that I thought was fuel rods has come from the north side of the building. And so could be from the 'equipment pool'



Amazing how much more sense the video means after a bit of site analysis (On here over these past few weeks)

 

[TCups]

Obviously, the are spraying water into something that they believe to be at least a partially intact SFP4 at the SE corner of Bldg 4. If the SFP4 were breeched, then wouldn't some of that water just be pouring out of that big hole in the side of the building?

Another interpretation might be that the heavily reinforced SFP4 shielded a blast originating from the level below reactor access floor above, and that the blast instead, exited to the west side of an intact SFP.

Which returns one to the original question: What was the origin of the component of the blast at the lower level(s).

What about the equipment pool and the NE corner of Bldg. 4? No teams spraying water here. Annotated image again from Fred's post.

http://i306.photobucket.com/albums/nn270/tcups/Bldg4NEcorner.png

And my original annotated image of the north face of Bldg 4.

http://i306.photobucket.com/albums/nn270/tcups/r735227_5964756.jpg

Have we now come the full circle, back to the infamous "Tongue"?

 

[Joe Neubarth]

If it's where the hole is to the south of centre in the roof of the building I'm pretty sure it's where the projectile like lump of heavy (concrete) blew upwards in the video and just pierced through the steel girders. this is where some of the steam is emanating.
Hope we can get full res images!
In fact looking at the 2 trails of debris on the roof of the turbine building (one with hole in it) the two lines of debris are almost parallel, suggesting that the explosion came from two sources, or it had two escape routes.
After re-examining... they do converge (Using the white lines at the very edge of turbine building) but to the north side of the building, not where the blurred area is, and the hole.

The biggest thing that was blown up into the sky in the Reactor Three explosion appeared to fall close to the tower (i.e. landside as opposed to oceanside). I think it landed in the middle of one of the small outlier buildings two spots over from the Tower. Whatever that Large Object was, I am willing to bet that it will tell the story of what caused the explosion. that was a heck of a lot of BROWN Dust for a steam explosion.

 

[Astronuc]

I'll comment later to the last few questions.

Meanwhile, based on a paper I just received, there are about 63 elements in the set of fission products of LWR fuel. Some are in extremely minute quantities.

The key elements of interest are:

U, Pu, (Np, Am, Cm)=f(BU) = fuel and transuranic elements (not fission products)

fission products:
Zr, Xe, Mo, Ce, Ru, Nd
Sr, Cs, Ba, La, Y, Tc, Pr
Rb, Te, Pd, I, Rh

Some are more significant radiologically or mobility-wise (Xe, Kr, I, Cs, . . . )

more later

 

[TCups]

The biggest thing that was blown up into the sky in the Reactor Three explosion appeared to fall close to the tower (i.e. landside as opposed to oceanside). I think it landed in the middle of one of the small outlier buildings two spots over from the Tower. Whatever that Large Object was, I am willing to bet that it will tell the story of what caused the explosion. that was a heck of a lot of BROWN Dust for a steam explosion.

Joe:

I looked very carefully at the earlier frames from the helicopter fly over as well as the satellite images. These are the two largest pieces of debris I could identify that were obviously out of place (arrows). I take them to be pieces of the roof of one of the buildings, perhaps from the large vertical blast at Bldg 3. Who knows?

Image from DigitalGlobe.com with my annotation.

http://i306.photobucket.com/albums/nn270/tcups/LgDebris.png

 

[artax]

Yes, I don't think that was a hydrogen explosion, well it was entirely different to the first explosion...I guessed that thing that went up and stayed partially intact was the missile protection PLUG for the reactor pressure vessel. in semicircles, 8 of them in total. which would suggest explosion inside concrete containment. Anyway yes there was an enormous amount of brown stuff went up, and went up a long way... like three times the height of the chimney stacks.
Haven't analysed exactly where the majority of it landed but would like to see the result in these better images.

 

[artax]

Joe:

I looked very carefully at the earlier frames from the helicopter fly over as well as the satellite images. These are the two largest pieces of debris I could identify that were obviously out of place (arrows). I take them to be pieces of the roof of one of the buildings, perhaps from the large vertical blast at Bldg 3. Who knows?

Image from DigitalGlobe.com with my annotation.

http://i306.photobucket.com/albums/nn270/tcups/LgDebris.png

The thing is they look quite large but not massive... as in heavy, i think for something to be in one piece like that after dropping from a great height it must be quite light in weight.
I'm pretty sure the concrete that didn't disintegrate immediately post explosion disintegrated on impact with the ground.
Anyone know how high the reactor biuldings and exhaust towers are?

Just found a new source of info updates, don't have time to read now, back tomorrow.

http://www.iaea.org/newscenter/news/tsunamiupdate01.html

 

[AntonL]

Joe:

I looked very carefully at the earlier frames from the helicopter fly over as well as the satellite images. These are the two largest pieces of debris I could identify that were obviously out of place (arrows). I take them to be pieces of the roof of one of the buildings, perhaps from the large vertical blast at Bldg 3. Who knows?

Image from DigitalGlobe.com with my annotation.

http://i306.photobucket.com/albums/nn270/tcups/LgDebris.png

How are you separating the debris left by Tsunami and debris from explosion

both are Tsunami debris, it can be identified http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichi_march13_2011_dg.jpg" just look carefully there is enough opening in the cloud cover at the right place - this is after unit 1 exploded 2 3 & 4 intact

 

[TCups]

How are you separating the debris left by Tsunami and debris from explosion

both are Tsunami debris, it can be identified http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichi_march13_2011_dg.jpg" just look carefully there is enough opening in the cloud cover at the right place - this is after unit 1 exploded 2 3 & 4 intact

Me? As I said, . . . "Who knows?"

 

[Reno Deano]

Reminds me of the blur effect in the Ringu films!

Well spotted, it's a strange looking effect indeed. Unlikely to be steam as it's in the same form in all views shot at different times...

Does it line up with the hotspot in the IR image released previously?

/edit on quick inspection it does indeed line up with the large white spot in the IR. One wonders how far above the temp at white that area actually is.

--------------------

From my point of view. Two units use a common single off gas release point. During a reactor accident situation the normal Off gas system initially isolates and the emergency off gas system is activated. A problems with the emergency charcoal beds is if they get loaded with radionuclides, especially fission products and are wetted they to can catch fire. When a station black out occurred the whole building filled with hydrogen out to the offgas piping exterior to the buildings. One plant had less hydrogen generated than the other. Hydrogen is orderless. Eventhough emergency backup battery operated lighting would come and other battery operated system there could have been a spark as operators tried to initiated backup power switching. The hydrogen builtup over a good period of time to fill the Reactor Building and some attached buildings. More than likely the initiating event for the hydrogen explosion was similar in all three reactors buildings. A good suspect is a emergency light or metalic spark from a relief valve. When left in auto-mode emergency electrical switches will cycle as power fluctuates or batteries drain. Just some idle thoughts.

 

[TCups]

--------------------

From my point of view. Two units use a common single off gas release point. During a reactor accident situation the normal Off gas system initially isolates and the emergency off gas system is activated. A problems with the emergency charcoal beds is if they get loaded with radionuclides, especially fission products and are wetted they to can catch fire. When a station black out occurred the whole building filled with hydrogen out to the offgas piping exterior to the buildings. One plant had less hydrogen generated than the other. Hydrogen is orderless. Eventhough emergency backup battery operated lighting would come and other battery operated system there could have been a spark as operators tried to initiated backup power switching. The hydrogen builtup over a good period of time to fill the Reactor Building and some attached buildings. More than likely the initiating event for the hydrogen explosion was similar in all three reactors buildings. A good suspect is a emergency light or metalic spark from a relief valve. When left in auto-mode emergency electrical switches will cycle as power fluctuates or batteries drain. Just some idle thoughts.

Which had the more hydrogen gas, in your opinion? Bldg 3, the one that blew sky high or Bldg 4, the one that blew out the bottom out of the building?

 

[AntonL]

It is semi-official, we speculated it to be so
Reactor Vessel 2 and 3 are breached
http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1301486904P.pdf

Japan's Nuclear and Industry Safety Agency says air may be leaking from the No 2 and No 3 reactors ...The agency said fluctuations in temperature and pressure are highly likely to have weakened valves, pipes and openings under the reactors where the control rods are inserted

 

[Reno Deano]

Iodine is a concern because of the uptake to the thyroid gland which is pretty sensitive.

http://en.wikipedia.org/wiki/Thyroid

I'm not sure about the pancreas.

Cs would also be important to know.

The further away from Fukushima, the lower the risk of contamination. The winds (jet stream) tend to blow west to east, but there are times when they can north or south, and a little bit westward, i.e., NNW or SSW.

I would expect that the other plants, e.g., Tohoku Electric's Onagawa and Higashidori plants are monitoring activity to the north, and JAPCO's Tokai plants to the south. What do they report?

----------------------------
IAEA 30 March 2011 Press Release on Reactor Crisis and Off-site monitoring should give you comfort in the water and food stuff consumption by the public. There is no significant health risks of drinking water or eating food stuffs outside of the reactor plant's exclusion zone.

http://www.iaea.org/press/?p=1852#more-1852"

 

[Joe Neubarth]

Which had the more hydrogen gas, in your opinion? Bldg 3, the one that blew sky high or Bldg 4, the one that blew out the bottom out of the building?

Structural weaknesses are the real issue there.

 

[TCups]

Structural weaknesses are the real issue there.

So the roof of 3 was weaker and the ground floors of 4 were weaker?

 

[Reno Deano]

Pick your postulate location of a breach or leak path. Mine is on the bottom of the reactor vessel.

 

[jensjakob]

One thing that really puzzles me.

I know that everything is relative.

But how on Earth can they claim that 1-10 % of radiation found inside active core is a low measurement?
--------

The Nuclear and Industrial Safety Agency says the levels of radioactive
substances detected are low, at one-to-ten percent of those occurring in an
operating nuclear reactor
---------
http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1301486904P.pdf

 

[TCups]

Pick your postulate location of a breach or leak path. Mine is on the bottom of the reactor vessel.

So the bottom of the reactor vessel in 3 leaked the hydrogen gas and the explosion was primarily in the upper floors of building 3, and the SFP4 in building 4 was the source of the hydrogen and the main force of the explosion was in the lower floors?

 

[TCups]

One thing that really puzzles me.

I know that everything is relative.

But how on Earth can they claim that 1-10 % of radiation found inside active core is a low measurement?
--------

The Nuclear and Industrial Safety Agency says the levels of radioactive
substances detected are low, at one-to-ten percent of those occurring in an
operating nuclear reactor
---------
http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1301486904P.pdf

Maybe they were talking about radiation in the infrared spectrum -- no -- they do say radioactive, and I presume they mean the cores in their current state (whatever that is) versus in a normally operating BWR at full power.

 

[AntonL]

Pick your postulate location of a breach or leak path. Mine is on the bottom of the reactor vessel.

Wrong!

With water being boiled by a 4.3MW heater at a rate of 6m3/hour, and the fuel rods being about 4metres tall and the upper 1.7 to 2 metres being above water, steam is escaping at some fantastic rate at any outlets above the water level.

If the top was intact and the leak at the bottom then no water would be in the vessel

You must always consider all facts before making a decision.

 

[ivars]

http://www.fairewinds.com/content/what-we-do"

Opnion of update on Fukushima by a Nuclear scientist. From the site-how water may have leaked outside containment, into trenches:

http://fairewinds.com/sites/default/files/bwr-crd5.jpg

 

[jensjakob]

Maybe they were talking about radiation in the infrared spectrum -- no -- they do say radioactive, and I presume they mean the cores in their current state (whatever that is) versus in a normally operating BWR at full power.

Unfortunately not - they are talking about the water in the trench being "only" 1-10% radioactive - which they refer to as "low compare to a core in action"

"
The Nuclear and Industrial Safety Agency says the levels of radioactive
substances detected are low, at one-to-ten percent of those occurring in an
operating nuclear reactor"