Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Jorge Stolfi]

Your scenario has three complications.

I have been almost entirely convinced that those straight tubes are not fuel rods.

Wiring or fluid ducts seem unlikely: ripping them off the walls/ceiling should have bent them at the attachment points. (As for loose spare ducts, why keep them on the working floor?)

Someone claimed they look like neutron-measuring instrumentation tubes; I suppose that is it.

 

[Joe Neubarth]

This last 7.1 quake happened only 12 miles away from Onagawa nuclear plant.

7.1 2011/04/07 14:32:42 38.253 141.640 49.0 NEAR THE EAST COAST OF HONSHU, JAPAN

NISA: Onagawa Nuclear Power Plant started emergency power generator, 1 external power-line left, so continue to cooling the fuel rod down

41 miles out to sea from Sendai.

 

[Joe Neubarth]

<sarcasm>Wouldnt TEPCO report that?</sarcasm>

Seriously - TEPCO has no possible way to state anything about the effect of the quake, since they don't have access to large parts of the plant due to radiation.

They can claim "Not identified any immediate damage in the areas that we can monitor".

But it is not valid to say "no additional damage", sorry

It was 40 miles closer than the 9.0 quake. Allowing for attenuation of the shockwaves from the epicenter, it should not have done much damage to intact structures. The non-intact structures are what we need to worry about if we are prone to worry.

 

[flyingblind]

Thank you for the great, well-organized site. Are you the author?

Author No.

 

[shogun338]

Thats the last thing they need is for another plant to have cooling failure . Two out of three external power lines to the Onagawa nuclear power plant, 75 miles northeast of Fukushima and near the epicenter of Thursday's temblor, have been damaged, causing power loss. The plant, operated by Tohoku Electric Power, has been shut down since the March 11 quake and has been relying on external power to cool the reactors. Japan’s Atomic Energy Agency said the two lost power lines were not being used for cooling when tonight’s earthquake hit.
http://www.csmonitor.com/World/Asia...sunami-warning-lifted-but-Fukushima-evacuated

 

[shogun338]

Toshiba Corp submitted a proposal to Tokyo Electric Power Co and the Ministry of Economy, Trade and Industry to dismantle the damaged Fukushima Daiichi nuclear power plant by 2020 http://www.reuters.com/article/2011/04/07/toshiba-idUSL3E7F73E720110407

 

[Sirius (b)]

Greetings everyone.

Here's the EQ information: http://quakes.globalincidentmap.com/; http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/quakes_all.html & http://geofon.gfz-potsdam.de/eqinfo/list.php

And this is a result of a FOIA to NRC: http://fukushimafaq.wikispaces.com/file/view/rst+assessment+26march11.pdf

This report was quoted in the NYT article, but we have more details now,

On Unit 3:

Primary Containment
Damage suspected (NISA, TEPCO) "Not damaged" (JAIF 10:003/25); Fuel pool is heating up but is adequately cooled, and fuel may have been ejected from the pool
(based on information from TEPCO of neutron sources found up to 1 mile from the units, and
very high dose rate material that had to be bulldozed over between Units 3 and 4. It is also
possible the material could have come from Unit 4);

ASSUMPTIONS: Rad Levels: DW 5100 R/hr, torus 150 R/hr (Industry); 100 R/hr debris outside Rx
building (covered).

SNF pool in number 3 is not the only worry that should captivate you, there's been a steam/thermal explosion in RPV, top of PCV breach with some of the debris landing SW of Unit 3-4 - where 3 out of 5 soil samples had been taken, contained pu- isotopes - http://www.tepco.co.jp/cc/press/betu11_j/images/110328n.pdf



Added: Unit 3 thermal imagery, March 20th, 2011, looking West:
http://img535.imageshack.us/img535/591/reactor3fuel.th.jpg

 

[ivars]

Many nuclear facilities have lost onsite or off-site power.

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

Onagawa Nuclear Power Plant:

NISA has confirmed that two out of the three lines supplying off-site power to the site were lost following the 7 April earthquake. Off-site power continues to be supplied through the third line.

Cooling of the spent fuel pool was temporarily lost, but has subsequently been restored.

Higashidori Nuclear Power Plant

NISA has confirmed that the Higashidori NPP was shutdown and in a maintenance outage at the time of the 7 April earthquake. Off-site power has been lost. Emergency power supply to the site is operating.

Rokkasho Reprocessing Plant

NISA confirms that Rokkasho Reprocessing Plant and uranium enrichment facility lost off-site power. Emergency power supply to the site is operating.

Now all what is needed is another aftershock of size >M7 to knock emergency power supply out.

 

[rmattila]

Not being familiar with the GE ECCS & MCP design, I have some worries about the status of the core cooling:

if the route through which water is being injected to the core is such that the flow either goes entirely through the feedwater nozzles or is divided between the core spray and the feedwater route, then it might be possible that

• the core spray nozzles have been clogged due to prolonged use of seawater (impurities, salt deposits)
• the water goes mainly or entirely to the downcomer, not on top of the core
• furthermore, if the main circulation loops have developed leaks, water will escape from the bottom of the downcomer to the recirculation loops and then to the leak

Adding to this the (i presume by now ascertained) fact that the level measurement monitors the level in the downcomer, not in the core, and the possibility that at least the upper temperature measurement monitors the temperature of the core vessel close to the feedwater inlet (=area affected by the inflow through feedwater lines), this currently leaves us very little on which to base estimates on the state of the cores. As I see it, it could be that only a little part (if any) of the water injected in the reactor vessel actually ends up cooling the core.

Based on the above guesses (I repeat that I really don't know the design details of the GE BWR:s very well), I think that the water samples collected from different parts of the plant could currently provide very important information regarding the degree of core damages. However, some of the nuclides that could be used to indicate high core temperatures (such as Sr-90) require rather sophisticated methodology to be identified, and I'm not sure the analysis methods currently used provide very good information regarding the important indicator nuclides.

Would somebody have better information on the core injection routes used at the Fukushima Dai-ichi plants? Is there some way to ascertain that the water injected in the reactor vessel actually reaches the core?

 

[Idaho_246]

If that's the case (and it may be), it is not a bit surprising that (a) the sound effects person added in all the rumbling noises as well as the dramatic bangs and (b) counterintuitively chose to add 3 bangs rather 1 or perhaps 2.

The sound may have been traveling a much more direct route to the mike than you experienced in those London bombs. Unless you were on top of Hampstead Heath or Crystal Palace (or the like) at the time, there would have been a lot more reflection/muffling etc from buildings between the explosions and your ears.

Someone earlier cited the timing as proof the sound was artificial. That isn't exactly proof - if the timing is off, the soundtrack may just have been shifted in time against the video so the sound was a closer match to the picture for TV purposes.

Is it possible that the soundtrack is from the reactor 2 explosions.

 

[MadderDoc]

[PLAIN]http://i.min.us/im7mIU.jpg[/QUOTE]

Part of the fhm from unit 3 may after initial service deck impact have rebounded, or slid off the deck, to land further down in the building which is annexed to the north face of the reactor building. See attachment with a top view with a arrow pointing to the spot, and a ground shot photo, looking up to the penetrated wall. About in the same area at groundlevel can be seen several smaller machine parts, perhaps of fhm3 origin.

Btw, interesting how the water spraying for cooling and 'firework' has had the effect of washing off a lot of dust since March 20th, revealing more clearly in video and photo what is in that big NW corner pile of debris.

http://www.gyldengrisgaard.dk/fuku_docs/perhaps_also_fhm3part_here.jpg

[URL]http://www.gyldengrisgaard.dk/fuku_docs/perhaps_also_fhm3part_here_groundshot.png[/URL]

 

[shogun338]

Part of the fhm from unit 3 may after initial service deck impact have rebounded, or slid off the deck, to land further down in the building which is annexed to the north face of the reactor building. See attachment with a top view with a arrow pointing to the spot, and a ground shot photo, looking up to the penetrated wall. About in the same area at groundlevel can be seen several smaller machine parts, perhaps of fhm3 origin.

Btw, interesting how the water spraying for cooling and 'firework' has had the effect of washing off a lot of dust since March 20th, revealing more clearly in video and photo what is in that big NW corner pile of debris.

http://www.gyldengrisgaard.dk/fuku_docs/perhaps_also_fhm3part_here.jpg

I have been looking at that corner on Unit 3 for awhile now . In some of the videos it almost looks like a dome . The is something large there .

 

[Sirius (b)]

The image Fred is showing looks like the lid of the RPV, you may want to compare it against early thermal imagery. ;)

 

[Joe Neubarth]

Thats the last thing they need is for another plant to have cooling failure . Two out of three external power lines to the Onagawa nuclear power plant, 75 miles northeast of Fukushima and near the epicenter of Thursday's temblor, have been damaged, causing power loss. The plant, operated by Tohoku Electric Power, has been shut down since the March 11 quake and has been relying on external power to cool the reactors. Japan’s Atomic Energy Agency said the two lost power lines were not being used for cooling when tonight’s earthquake hit.
http://www.csmonitor.com/World/Asia...sunami-warning-lifted-but-Fukushima-evacuated

They still have their emergency diesel generators as back up for each reactor.

 

[|Fred]

lid is color coded yellow <=100% certain
green is color for FHM and crane <=100% certain
pink is color code for (hydraulic stuff) <= guessing

 

[Sirius (b)]

They still have their emergency diesel generators as back up for each reactor.

Indeed, but how long is the fuel going to last, batteries next? With destroyed electric grid in several prefectures (downed pylons, blown transformers) they are in a race against time with Higashidori NPP, possibly Onagawa's SNPs (reactors in cold shutdown as of March 11th).

lid is color coded yellow <=100% certain
green is color for FHM and crane <=100% certain
pink is color code for (hydraulic stuff) <= guessing

Pink is the guard railing around SNF & equipment pools. PCV dome could be inside turbine building of Unit 3, or it could be in the ocean.

 

[shogun338]

Indeed, but how long is the fuel going to last, batteries next? With destroyed electric grid in several prefectures (downed pylons, blown transformers) they are in a race against time with Higashidori NPP, possibly Onagawa's SNPs (reactors in cold shutdown as of March 11th).



Pink is the guard railing around SNF & equipment pools. PCV dome could be inside turbine building of Unit 3, or it could be in the ocean.

Thats what I was thinking about fuel running out . I think the guard rails around the spent fuel pools are covered in a green fabric or plastic . If you look in Unit 4 where there pumping water you can still see part of it below the FHM . The pic posted of it before the accident also shows green covered rails .

 

[Giordano]

I'm intersted in the amount of radioactive material leaked into the sea.

My attempt to estimate the ocean pollution of Cs-137 from the leak that was fixed the day before yesterday:

2 l/s -> 3600 m3 in three weeks.

Concentration of Cs-137 is assumed to be 1.8 MBq/cm3

Which gives 6.5 PBq of Cs-137 from one leak!

(Chernobyl totally released 85 PBq of Cs-137 in aerosol form according to Wikipedia)

Is my estimate reasonable? Can anyone make a better one?

Regarding the assumption of Cs-137 concentration:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110405e30.pdf
http://www.tepco.co.jp/en/press/corp-com/release/11040506-e.html

 

[Borek]

2 l/s -> 3600 m3 in three weeks.

Concentration of Cs-137 is assumed to be 1.8 MBq/cm3

Which gives 6.5 PBq of Cs-137 from one leak!

You are assuming constant contamination all the time.

 

[|Fred]

Giordano this may help

French scientists simulate how the radioactivity dilutes into the Pacific Ocean : http://sirocco.omp.obs-mip.fr/outils/Symphonie/Produits/Japan/SymphoniePreviJapan.htm
See also the simulation after 72 days on page 8/9 of http://www.irsn.fr/FR/Actualites_pr...ident-Fukushima-sur-milieu-marin_04042011.pdf

 

[Sirius (b)]

Thats what I was thinking about fuel running out . I think the guard rails around the spent fuel pools are covered in a green fabric or plastic . If you look in Unit 4 where there pumping water you can still see part of it below the FHM . The pic posted of it before the accident also shows green covered rails .

Then the paint has peeled off during the steam build up/explosion from SNP of number 4. And yes, those are fuel assemblies (what's left of them) that can be seen from the footage with the camera strapped to the concrete pump.

I'll check my archive to bring you the construction of Fukushima Daichi during the 1970s - blast from the past.

Fuel Assemblies in use at these reactors are not silvery grey, but black in colour.
Added: http://www.youtube.com/watch?v=cTshYXmN1AY&feature=mfu_in_order&list=UL at mark 1:10.

Unit 4, March 20th. What's your guess as to the temperatures we might be seeing here?

 

[Giordano]

You are assuming constant contamination all the time.

Yes I am assuming the leak was going on since they filled everything with water, you think that is a poorly made assumption?

They discovered the leak maybe a week ago, but don't you think it's been going on for a long time?

And the concentration I assume was even higher in the beginning rather than from the time the sample was made that I used. Maybe my estiamate qualifies as a lower boundary!?

 

[Giordano]

Giordano this may help

Thank you for response.

SCIROCCO writes:

"We are not able to prescribe in our model realistic scenarios as we do not know how much radionuclides have been rejected, when they have been rejected and how they behave once they reach the sea. That is why we do not claim that our simulations are able to provide a quantification of radioactivity in the sea."

I don't think they make assumptions of quantities!?

The second document has this interesting piece of information concerning "normal" levels of Cs-137 in Japanese waters:
"A titre de comparaison, avant l’accident de Fukushima, les niveaux de concentration
en césium 137 dans l’eau de mer du littoral japonais étaient de quelques mBq/L (1 à 3 mBq/L) et l’iode 131 n’était pas détecté."

 

[Borek]

Yes I am assuming the leak was going on since the filled everything with water, you think that is poorly assumed?

They discovered the leak maybe a week ago, but don't you think it's been going on for a long time?

And the concentration I assume was even higher in the beginning rather than from the time the sample was made that I used.

I am not judging your assumptions, I am naming them. Intuition tells me you can be wrong by orders of magnitude - each direction, although overestimate seems more likely.

I doubt such a high radioactivity leak could go unnoticed for long, so my bet is that leak was there earlier, but it was detected when radioactivity got higher - which could suggest radioactivity wasn't that high initially.

But it is way too speculative for my liking.

 

[shogun338]

Then the paint has peeled off during the steam build up/explosion from SNP of number 4. And yes, those are fuel assemblies (what's left of them) that can be seen from the footage with the camera strapped to the concrete pump.

I'll check my archive to bring you the construction of Fukushima Daichi during the 1970s - blast from the past.

Fuel Assemblies in use at these reactors are not silvery grey, but black in colour.
Added: http://www.youtube.com/watch?v=cTshYXmN1AY&feature=mfu_in_order&list=UL at mark 1:10.

See pics of reactor room and spent fuel pool in post #2650 . Where did you get the fuel assemblies are black ?

 

[Sirius (b)]

See pics of reactor room and spent fuel pool in post #2650 . Where did you get the fuel assemblies are black ?

https://www.physicsforums.com/showpost.php?p=3230265&postcount=2889

Point 1 - several 'intact' assemblies, 200 mm across. Refer to thermal image in my post above.

Added: On the question of the colour of the housing for the pellets - http://www.youtube.com/watch?v=cTshYXmN1AY&feature=mfu_in_order&list=UL at mark 1:10.

 

[heckler73]

Yes I am assuming the leak was going on since they filled everything with water, you think that is a poorly made assumption?

What is the function for your analysis? I am assuming concentration of outflow water will go down exponentially (from whatever event is the source).
Your analysis assumes linear concentration over time, it seems.
Is there any information on the actual source(s) of the contamination?
Where, When, How, etc...

ref: JAIF Trends for Seawater Radiation
http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1302167890P.pdf

 

[Giordano]

I am not judging your assumptions, I am naming them. Intuition tells me you can be wrong by orders of magnitude - each direction, although overestimate seems more likely.

I doubt such a high radioactivity leak could go unnoticed for long, so my bet is that leak was there earlier, but it was detected when radioactivity got higher - which could suggest radioactivity wasn't that high initially.

But it is way too speculative for my liking.

I agree it is speculative and an error by orders magnitude is possible.

I was trying to get some numbers to the quite common statement that it is better to pollute the sea rather than the atmosphere/land.

 

[rmattila]

Adding to my previous speculation on whether the cooling water injected actually goes into the core as desired:

does anybody have an idea whether it would be possible to inject water into the core through the control rod drive mechanism pipes in the BWR3/4 reactors? In the ASEA BWR:s, there is a constant rinse flow of the order of 10 kg/s during operation in order to keep crud away from the drive mechanisms, and in case of emergency, this route could in principle be used to drive water into the core from below. I've heard that in some new BWR designs this injection route is considered as a possible diverse system for the high pressure core injection.

 

[MJRacer]

Re Unit 3 explosion

Assuming that the objects that seem to have been lifted to great heights (>500m?) may have been roof tiles (as others have also surmised), how is it possible aerodynamically given air resistance? Looking at videos of the explosion, it looked to me like they might have been surfing on top of a ball or sphere of very hot gas that was rapidly rising, until they fell off one by one.

How hot would such a sphere have to be? At this website (http://tornado.sfsu.edu/geosciences/classes/m201/buoyancy/CAPE_Procedure.html), I found a relatively simple formula for calculating the acceleration of a parcel of air based on differences in temperature. The formula is a=(T_ap - T_e)/T_e*g, where T_ap is the temperature of the air parcel and T_e was about 16°C or 289.15 K at 11:00AM on 3/15(??) and g is the acceleration of gravity.

By looking at the video of the explosion (<iframe title="YouTube video player" width="640" height="390" src="http://www.youtube.com/embed/Q-9ax_X_PQ4" frameborder="0" allowfullscreen></iframe>), I estimated the initial acceleration of the sphere of gas AFTER the initial expansion somewhat at ground level to be about 50m/sec^2 using the vent towers for scale (~100m tall). T_a then would be about <b>1500°C</b> for a sphere about 50m to 100m in diameter AFTER the initial expansion. This very high temperature raises the question of whether a hydrogen explosion alone could have cause this. Maybe somebody else can look at this.

Should the possibility that a criticality event may have happened in SFP 3 then be considered? Such a criticality probably would have lasted only a few millliseconds, but it may have flashed a good bit of the remaining water in the pool to cause the initial expansion. A hydrogen explosion may have also taken place and, perhaps, the shock wave from the hydrogen explosion may have helped create the criticality in the first place. Again, just surmises.

If such an event did take place, it would have dispersed or partially dispersed the contents of SFP 3 outside the pool, thus explaining the very hot stuff that was bulldozed over between units 3 and 4 and finds elsewhere on the premises. It would also explain the video showing the cloud of debris rising as if shot out of a cannon. Also, it would explain how the RPV and the PCV could have remained fairly intact, because the reinforced concrete walls of the SFP would have shielded them. However, every other part of the building that was pneumatically connected to the SFP would have suffered severe damage.

Finally, this is all a maybe. Just food for thought.

 

[Giordano]

What is the function for your analysis? I am assuming concentration of outflow water will go down exponentially (from whatever event is the source).
Your analysis assumes linear concentration over time, it seems.
Is there any information on the actual source(s) of the contamination?
Where, When, How, etc...

ref: JAIF Trends for Seawater Radiation
http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1302167890P.pdf

Thank you for answering.

I'm not quite sure I understand you.

My purpose was to try to get a feeling (a lower boundary perhaps) for how much radioactive material had reached the ocean and how big volume of water that is need to dilute it to normal levels. I used the leak in front of unit 2 becuase I thought I had some numbers that were useful. Also Cs-137 has quite a long half-time so the environmental impact can be significant, which is the reason why I focused on that nuclide.

Yes, I assumed linear conc over time, it's the best I managed, based on the facts I had.

I didn't think so much of the specific event. But I did look at this document: http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110327e15.pdf
It measures the conc of Cs-137 in the water under the turbine building under unit 2, a week earlier to a bit higher levels.

Thank you for the doc. I had actually missed that one but I have been wathching here:
http://www.mext.go.jp/english/radioactivity_level/detail/1304192.htm

Would you like to make an estimation?

 

[Borek]

T_a then would be about <b>1500°C</b> for a sphere about 50m to 100m in diameter AFTER the initial expansion. This very high temperature raises the question of whether a hydrogen explosion alone could have cause this.

No problems here - adiabatic flame temperature for air/hydrogen mixture is well over 2000 °C.

That said, I don't like the rest of your analysis - equation you refer to is used for buoyant force, that's not the case here.

 

[PietKuip]

I'm intersted in the amount of radioactive material leaked into the sea.

My attempt to estimate the ocean pollution of Cs-137 from the leak that was fixed the day before yesterday:

2 l/s -> 3600 m3 in three weeks.

Concentration of Cs-137 is assumed to be 1.8 MBq/cm3

Which gives 6.5 PBq of Cs-137 from one leak!

(Chernobyl totally released 85 PBq of Cs-137 in aerosol form according to Wikipedia)

Is my estimate reasonable? Can anyone make a better one?

Regarding the assumption of Cs-137 concentration:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110405e30.pdf
http://www.tepco.co.jp/en/press/corp-com/release/11040506-e.html

Good work. I had been looking for a pair of such numbers: flow and activity of the same water.

 

[shogun338]

https://www.physicsforums.com/showpost.php?p=3230265&postcount=2889

Point 1 - several 'intact' assemblies, 200 mm across. Refer to thermal image in my post above.

Added: On the question of the colour of the housing for the pellets - http://www.youtube.com/watch?v=cTshYXmN1AY&feature=mfu_in_order&list=UL at mark 1:10.

4 is pointing to the rail that surrounds the spent fuel pool . The smaller rods could be older spent fuel rods that have cooled for years so not to hot . The large grey mass looks like something that has melted . The FHM is has collapsed on top of spent fuel pool and crushed some of the railing around the spent fuel pool .

 

[Sirius (b)]

Racer,

The height of the gas vent towers is 130 metres. There 3 are distinct pieces of debris seen emerging from the vertical dust cloud, they could be either: FHM, PCV dome, concrete DW plug, reactor lid itself. The SFP is not the cause of the explosion, there may have been hydrogen in the secondary containment (reactor room), but the trigger was the thermal explosion inside the RPV - cold water coming into contact with 3/4 melted core, which, possibly fell down to the bottom of the RPV, triggering the steam release via the most likely route - bolted top. While the torus may have been destroyed in the event, I would worry about fuel from the core and SFP of Unit 3.

Concrete was pulverised in the detonation, that is steel debris flying sky-high to 500 metres+, with the cloud reaching up-to 1 km, or more.

P.S. What pressure was reported for Unit 3 D/W, RPV prior to the explosion? The core had already melted to some percentage before then, otherwise you can't have the observed events.

4 is pointing to the rail that surrounds the spent fuel pool . The smaller rods could be older spent fuel rods that have cooled for years so not to hot . The large grey mass looks like something that has melted . The FHM is has collapsed on top of spent fuel pool and crushed some of the railing around the spent fuel pool .

Yes. Whatever was the cause of the damages seen to Unit 4 building, it blew a hole 8 metres in diameter South to North through it, around the level the fuel assemblies would be stored at.

If anyone is interested in latest thermal imagery of the plant, PM me and I'll get them sourced and uploaded.

 

[RealWing]

Adding to my previous speculation on whether the cooling water injected actually goes into the core as desired:

does anybody have an idea whether it would be possible to inject water into the core through the control rod drive mechanism pipes in the BWR3/4 reactors? In the ASEA BWR:s, there is a constant rinse flow of the order of 10 kg/s during operation in order to keep crud away from the drive mechanisms, and in case of emergency, this route could in principle be used to drive water into the core from below. I've heard that in some new BWR designs this injection route is considered as a possible diverse system for the high pressure core injection.

Injection via the CRD's is one of the routes that the NRC was recommending

"4. CRD injection is desired for cooling directly to the core and for cooling material on
bottom of vessel"

 

[Borek]

Which gives 6.5 PBq of Cs-137 from one leak!

"A titre de comparaison, avant l’accident de Fukushima, les niveaux de concentration en césium 137 dans l’eau de mer du littoral japonais étaient de quelques mBq/L (1 à 3 mBq/L) et l’iode 131 n’était pas détecté."

I was trying to get some numbers to the quite common statement that it is better to pollute the sea rather than the atmosphere/land.

The volume of the Pacific Ocean is around 600 million cubic km.

Full dilution gives 0.01m Bq/L (unless I miscounted zeros, too many of them) - 300 times less than the background. Sure, full dilution is unrealistic.

 

[cola]

I'm intersted in the amount of radioactive material leaked into the sea.

My attempt to estimate the ocean pollution of Cs-137 from the leak that was fixed the day before yesterday:

2 l/s -> 3600 m3 in three weeks.

Concentration of Cs-137 is assumed to be 1.8 MBq/cm3

Which gives 6.5 PBq of Cs-137 from one leak!

(Chernobyl totally released 85 PBq of Cs-137 in aerosol form according to Wikipedia)

Is my estimate reasonable? Can anyone make a better one?

Regarding the assumption of Cs-137 concentration:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110405e30.pdf
http://www.tepco.co.jp/en/press/corp-com/release/11040506-e.html

hello. i can't give you any hard numbers, but Robert Peter Gale who coordinated the medical relief efforts for victims of the Chernobyl disaster and who is in J-Village, where all the international experts in fukushima berate, writes in german spiegel magazine that so far in fukushima 10% of the chernobyl-amount of iodine-131 and caesium-137 have leaked.
he also writes that he doesn't expect many deaths from this and that smoking is more dangerous for manchild than this etc. though.
forgive my bad english, i often get probs with the syntax when building too long sentences.

 

[Jorge Stolfi]

Sorry, I may not be able to update my plots of Fukushima Daiichi vars until next tuesday.
(However the scripts and files are availabe at the site, if anyone cares...)
http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/

 

[tadjik]

Where do you find the source material ?
I have this link in english http://www.nisa.meti.go.jp/english/ , but the information are 2 days old.

hello. i can't give you any hard numbers, but Robert Peter Gale who coordinated the medical relief efforts for victims of the Chernobyl disaster and who is in J-Village, where all the international experts in fukushima berate, writes in german spiegel magazine that so far in fukushima 10% of the chernobyl-amount of iodine-131 and caesium-137 have leaked.
he also writes that he doesn't expect many deaths from this and that smoking is more dangerous for manchild than this etc. though.
forgive my bad english, i often get probs with the syntax when building too long sentences.

Maybe ... anyway, there will be, on the long run, chronic exposure to caesium for the area inhabitants. Even at low levels, this could have an effect on health (read somewhere that it has an effect on foetus formation although the effect on adults is not so strong).

 

[Giordano]

hello. i can't give you any hard numbers, but Robert Peter Gale who coordinated the medical relief efforts for victims of the Chernobyl disaster and who is in J-Village, where all the international experts in fukushima berate, writes in german spiegel magazine that so far in fukushima 10% of the chernobyl-amount of iodine-131 and caesium-137 have leaked.
he also writes that he doesn't expect many deaths from this and that smoking is more dangerous for manchild than this etc. though.
forgive my bad english, i often get probs with the syntax when building too long sentences.

Thank you for your answer.

Interesting and somewhat comforting figures.

Have you seen this:
http://www.zamg.ac.at/docs/aktuell/Japan2011-03-22_1500_E.pdf

 

[Giordano]

Sorry, I may not be able to update my plots of Fukushima Daiichi vars until next tuesday.
(However the scripts and files are availabe at the site, if anyone cares...)
http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/

I think your plots are great. And I will wait patiently for your updates.

(I have actually been in Campinas once and walked around the lake.)

 

[MJRacer]

Sirius

From: http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/Main.html
Unit 3 on 3/14 at 9:00 AM:
Core: 409 kPa
D/W: 490 kPa
torus: 475 kPa

 

[cola]

Thank you for your answer.

Interesting and somewhat comforting figures.

Have you seen this:
http://www.zamg.ac.at/docs/aktuell/Japan2011-03-22_1500_E.pdf

thanks.sounds interesting and seems to be much more than stated by that guy who wrote the article i mentioned.the article( http://www.spiegel.de/spiegel/0,1518,754931,00.html ) he wrote in the german magazin was titled 'german angst' (german fear) and was generally saying it wasnt all so bad.if that is the trend in their camp there...
enough of my no numbers games :p

 

[Sirius (b)]

Sirius

From: http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/Main.html
Unit 3 on 3/14 at 9:00 AM:
Core: 409 kPa
D/W: 490 kPa
torus: 475 kPa

Thanks, is that above the designed limit for this Mk I type of BWR reactors? A sudden increase in pressure could render events observed.

Pressure readings in both RPV and dry well at 1 atm tells you the story, that I've told you before. :)

Must read new report from Areva dated April 7th - http://www.fairewinds.com/sites/default/files/AREVA%20Fukushima.pdf I haven't started yet, but if it's anything like the one from 26th, it will be good. (apart from the fact that they've explained Unit 1 and applied the same theories both to 2 & 3), here it is - http://www.megaupload.com/?d=OJS80EGJ

 

[elektrownik]

This is Japanese but it is always updated before english version, you can translate it with google, but even without translation data are in tables and on drawings so it is easy to understand: http://www.nisa.meti.go.jp/itiran/new_genshi_index.html

 

[PietKuip]

NHK has found some Tepco data from the day of the quake. In unit 1, the water level sank to 45 cm over the fuel rods. If I remember correctly, that was 7 hours after the quake.

The pressure in the pressure vessel went down, and the pressure in the containment vessel had gone up. NHK says this suggests that pressure vessel had become leaky because of earthquake damage (not tsunami induced).

 

[clancy688]

About Mr. Gale:
Most germans are very, very frightened of nuclear power. I don't think there's any other country in the world which can top our hysterical reaction to the Fukushima accidents. Not even Japan. And not even close.
So Mr. Gales report was "not received well" (understatement of the century), because in most german minds, he's downplaying the accident massively.
But if even he states, that Jod-131 and Cesium-137 emissions are at 10% of Tchernobyl, then there must be significant radiation spreads. (Btw, "only 10% Tchernobyl" my ***... is he kidding? If Fukushima is at 10% Tchernobyl, Japan is in deep **** now...)

Have you seen this:
http://www.zamg.ac.at/docs/aktuell/Japan2011-03-22_1500_E.pdf

That's a very old estimate of the radiation release. ZAMG has updated its expectations frequently, the latest one being only a few days old (2nd April). But it's not available in english:
http://www.zamg.ac.at/aktuell/index.php?seite=1&artikel=ZAMG_2011-04-02GMT09:28

I will translate:

Airborne emission estimate of Jod-131 and Cesium-137 during the first week:

March 14th:
Jod-131 10^16 to 10^17 Bq/day
Cesium-137 10^15 to 10^16 Bq/day

March 12th-13th, 15th-19th:
Jod-131 10^14 bis 10^17 Bq/day
Cesium-137 10^13 to 10^16 Bq/dayConclusion:
Between 10^16 and 7 * 10^17 Bq Jod-131 and between 10^15 and 7 * 10^16 Bq Cesium-137 have been released during the first week. There's another estimate by IRSN:
http://www.irsn.fr/FR/Actualites_presse/Actualites/Documents/NI-terme-source-22032011-tableau.pdf

9 * 10^16 Bq Jod-131 and 10^16 Cesium-137 between March 12th and 22th.

But those are ONLY airborne emissions.

 

[|Fred]

...

This actually is almost to the letter the romance imagined by a French journalist with a PhD in Nuclear Physic about three weeks ago, I'm surprise that it's still considered as it was obvious that it was a non sens, even three weeks ago.

Would you be kind enough to point out the 8m S/N Hole around the floor where the fuel assemblies are stored ?

 

[MJRacer]

Same source states 400 kPa is maximum D/W pressure.