Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[MiceAndMen]

Here is a similar set of pics but going out to a distance of 16 km from the plant.

Has anyone tried to contact NHK or some other Japanese media outlet to ask the direct question of where the camera was situated at the time Unit 3 exploded?

 

[drdodge]

if anyones interested

latest drone photos here

http://www.cryptome.org/

dr dodge

 

[AntonL]

Are there any good options (i.e. free) for uploading large images to the web? I have some more Oyster Creek drawings, but they are very large. I uploaded a couple to photobucket but they have a size limit that makes the result useless.

http://min.us/"

 

[rowmag]

Here is a similar set of pics but going out to a distance of 16 km from the plant.

Has anyone tried to contact NHK or some other Japanese media outlet to ask the direct question of where the camera was situated at the time Unit 3 exploded?

No, but I recall them saying that the cameras were located beyond the evacuation zone, which at the time of the #3 blast was 20 km in radius. So might want to try extending your search to at least 20 km from the plant.

 

[MiceAndMen]

http://min.us/"

Thanks AntonL!

Oyster Creek Reactor Building General Arrangement (approx. 1 MB)
http://i.min.us/ikukv6.jpg

Oyster Creek Reactor Building Refueling Level (approx. 5 MB)
http://i.min.us/ikum3E.jpg

The second pic shows a lot of little details, such as the height of the 4 reactor cavity shield plug slabs being 7 feet (2.13 meters). Note that the differences between the Oyster Creek plant and the Fukushima reactors are quite possibly non-trivial. It would be really nice if TEPCO would release a set of drawings but I don't think that's going to happen.

I'll find the URLs for the PDFs I have of the Oyster Creek drawings. There are 4 PDF files totalling about 23 MB. Hmmm... now that I think about it, there are no direct PDF download URLs, you'll have to navigate an NRC website to get to them. I'll post how to do that tomorrow.

I spent more than a few hours searching for reactor building blueprints on the NRC site, and the ones for Oyster Creek are the only ones I could find. Others haven't been scanned into PDF form yet, and still others are, I think, not publicly available at all. That's too bad because I believe the closest reactors in the US to the Fukushima Daiichi ones are the ones at Vermont Yankee and (now closed) Millstone I.

 

[AtomicWombat]

I don't think that is a plausible damage from heat.

Allow me to draw your attention to a possible suspect at the foot of the building (see attachment). It is found at the scene of the crime, in a plausible position after an assumed hammering of unit 4's north side. It appears to be a boiler tank or something of that sort, about 10 meters long, about 3 meter in diameter. It appears to have been blasted. And, perhapos significantly, it appears to be lying on top of pieces of unit 3's roof construction.

I think that's a crane.

 

[liamdavis]

It seems that the explosions at each plant would leave distinct evidence as to its nature. A shattering (high velocity) explosion should leave some sharp ragged edges on the concrete structure. Where as propellant (low velocity) damage should show erosion.

Water turning to steam expands about 1728 times in volume. It starts out with no velocity and accelerates. The speed it obtains between its point of origin and the building walls would give it an energy impulse upon impact similar to an explosion. However, between being water and being steam at full expansion, it would behave much like a fluid. If a significant quantity of water flashed to steam and had only expanded to 2-400 times its volume at the time it initially pushed the wall panels out then it would leave the marks of a (debris laden) fluid eroding the remaining concrete structure.

Hi-res close-up pictures of the remaining vertical supports and the underside of horizontal structure should bring clarity to which event happened at which buildings. This would make the reconstruction of events more focused and productive.
liam

 

[HowlerMonkey]

I wonder if the reason for the higher temperature at the bottom of #3 is the cool water is being injected at the top and the heated water is leaking past the sensor out the bottom?

 

[GJBRKS]

I wonder if the reason for the higher temperature at the bottom of #3 is the cool water is being injected at the top and the heated water is leaking past the sensor out the bottom?

At 252 Celsius and low pressure that water is not liquid water anymore.
Steam will not attain this temperature without external heating

 

[AtomicWombat]

@TCups, you posted the picture, You remember where you got it?

I got it from a news site, and TCups annotated it.

It was the first picture released by TEPCO.

 

[|Fred]

I think that's a crane.

Are you referring to the yellow trucks ?

 

[NUCENG]

I don't think it'd matter noticeably that it'd take away neutrons, if the coating is very thin (e.g. a few micrometers), but a significant fraction of it would still turn into mercury, so you'd get some sort of gold-mercury amalgam. I really don't know if it would even remain there at all. Plus the mercury tends to have corrosive effect. edit: plus, perhaps, electrochemical corrosion as well, if any of gold flakes off.

That is the point. With its relatively large cross section, if you put a thin layer of gold in the area of highest neutron flux in the reactor, it won't be there very long.

 

[NUCENG]

We will not see any isotopes until tepco will give us data about them, they give us now only I and Cs...

One of the clues would be another huge release of iodine. That hasn't happened from their data. Slow increases in iodine would potentially indicate reevolution of iodine gas due to pH in pools becoming acidic. A sudden huge release would occur from interaction with concrete releasing a whole new set of chemicals.

 

[NUCENG]

I think the following image argues against this admittedly intriguing idea:
http://livedoor.2.blogimg.jp/dqnplus/imgs/6/d/6dffb5e9.jpg
That was on 3/14, after #3 blew up but before #4 did.
The damage to building #3 seems largely complete at this point already.
#4 has no visible damage yet.

Zoom in of the above:

Compare with the next day, after whatever had happened to #4:
[URL]http://www.tepco.co.jp/en/news/110311/images/110316_1f_chijou_1.jpg[/URL]

They look about the same to me...

Lacking explanation for internal hydrogen explosions in Unit 4 due to TEPCO reports of conditions in the fuel pool of Unit 4, there are two possibilities: internal explosion from another souce, or external exposion.

My experience with BWRs including refueling outages is that there is no internal source that could justify the kind of damage I see. Acetylene is used for cutting, but in small tanks brought to each work site. Most welding is arc welding. There are lubricants, but not in confined containers that could develop the kinds of forces evident in the damage.

I agree there are pictures showing the damage to Unit 4 was after the explosion of unit 3. But there seem to be significant differences between those picture of unit 3 and pictures taken after unit 4 showed damage. The early pictures show parts of the third and fourth floors still standing on Unit 3. Current pictures show only 2nd and part of 3rd floors.

My focus was the area at the wall of unit 4 which appears to be bent inwards. That is my evidence of the direction of force. I'm looking for a set of photos of unit 3 that can prove the timeline, but so far have problems with confirmed times for the photos.

 

[clancy688]

Packbot(s) entered into reactor buildings 1 & 3, after opening some of the doors connecting with the turbine buildings. Measurement results are expected to be released on April 18th or later : http://www.jiji.com/jc/c?g=soc_30&k=2011041700293

http://english.kyodonews.jp/news/2011/04/86132.html

Radiation levels are at 10-49 mSv/h in Unit 1 and 28-57 mSv/h in Unit 3. Why are they not checking Unit 2?

As far as I know, the only difference between Unit 2 and the other Units is, that Unit 2s secondary containment has been flooded. Does that mean that they send these robots into the secondary containments of Units 1 and 3? And then do these radiation levels imply, that there the RPV has not been breached? (Aside from ruptured valves and such)

 

[AtomicWombat]

Allow me to draw your attention to a possible suspect at the foot of the building (see attachment). It is found at the scene of the crime, in a plausible position after an assumed hammering of unit 4's north side. It appears to be a boiler tank or something of that sort, about 10 meters long, about 3 meter in diameter. It appears to have been blasted. And, perhapos significantly, it appears to be lying on top of pieces of unit 3's roof construction.

I think that's a crane.

Are you referring to the yellow trucks ?

I think what MadderDoc is pointing to (thumbnail) is one of these cranes.

 

[razzz]

The way I'm picturing the cores and cooling is that there are leaks so whatever water level that can be maintained is the same level the rods will melt down to even if they have to flood the whole basement to get the water level constant. In the meantime, fluctuating water levels cause fuel to react to the environment besides the constant bleeding of contaminated water while waiting for a cool down(s).

From a previous posted link http://canteach.candu.org/library/20044507.pdf" which is in .pdf format, the author notes steam is a better coolant but when nitrogen is injected (to displace hydrogen) it causes core temperature to rise. This is the same paper that tries to cover all possible angles during a nuke accident but in hindsight omits seawater ramifications when used as coolant.

Also, how can you stop the contaminated seawater from entering and contaminating the ground water table as the ocean permeates the shoreline esp. during tidal movements?

 

[|Fred]

The early pictures show parts of the third and fourth floors still standing on Unit 3. Current pictures show only 2nd and part of 3rd floors.

I do not agree with this statement , I do not see the missing part you are referring to, could you please point them out


AtomicWombat, crane as is crane truck or as in crane equipment from the Nuk Building ? I think I missread you you were speaking of crane truck but since so far we were talking about crane equipment..

 

[Samy24]

http://english.kyodonews.jp/news/2011/04/86132.html

Radiation levels are at 10-49 mSv/h in Unit 1 and 28-57 mSv/h in Unit 3. Why are they not checking Unit 2?

As far as I know, the only difference between Unit 2 and the other Units is, that Unit 2s secondary containment has been flooded. Does that mean that they send these robots into the secondary containments of Units 1 and 3? And then do these radiation levels imply, that there the RPV has not been breached? (Aside from ruptured valves and such)

You can not trust any of the readings/reports. Because it's TEPCO and the press most of the time do not know what they are writing about.

The same website reports 270 mSv at the gateway to Unit 1. That implies that the radiation is higher inside the gateway than inside the reactor building. Make your conclusions please.

http://www3.nhk.or.jp/daily/english/18_03.html"

 

[elektrownik]

http://english.kyodonews.jp/news/2011/04/86132.html

Radiation levels are at 10-49 mSv/h in Unit 1 and 28-57 mSv/h in Unit 3. Why are they not checking Unit 2?

As far as I know, the only difference between Unit 2 and the other Units is, that Unit 2s secondary containment has been flooded. Does that mean that they send these robots into the secondary containments of Units 1 and 3? And then do these radiation levels imply, that there the RPV has not been breached? (Aside from ruptured valves and such)

I think that they don't check s/c yet... also there is some error in translation, from picture and tepco news I think that they send 2 robots to #3 building, and nothing yet to #1..

 

[AtomicWombat]

AtomicWombat, crane as is crane truck or as in crane equipment from the Nuk Building ? I think I missread you you were speaking of crane truck but since so far we were talking about crane equipment..

Sorry I meant truck mounted cranes. I'm pretty sure they were there before the explosion in unit 3.

 

[Krikkosnack]

Yes, but that height gives us only information about initial speed - we don't know mass, so we can't tell anything about amount of energy. And if I remember correctly the idea of OP was to calculate mass from this data - and this is simply impossible. It is not an accident that in the simplest approach - mgh=mv²/2 - mass cancels out

Magnificent, you are a kind of genius. I would never have got there!
I simply said that I wanted to estimate its mass if we were able to calculate the energy involved during the explosion as I know the height at which these items have gone up. If you do not want to contribute, you are not required to do so..

 

[DSamsom]

Apparantly NISA announced that the reactor builing No 4 is now flooded in 5 meters of water. Anyone to explain this? Do they mean the SFP?

 

[TCups]

It seems that the explosions at each plant would leave distinct evidence as to its nature. A shattering (high velocity) explosion should leave some sharp ragged edges on the concrete structure. Where as propellant (low velocity) damage should show erosion.

Water turning to steam expands about 1728 times in volume. It starts out with no velocity and accelerates. The speed it obtains between its point of origin and the building walls would give it an energy impulse upon impact similar to an explosion. However, between being water and being steam at full expansion, it would behave much like a fluid. If a significant quantity of water flashed to steam and had only expanded to 2-400 times its volume at the time it initially pushed the wall panels out then it would leave the marks of a (debris laden) fluid eroding the remaining concrete structure.

Hi-res close-up pictures of the remaining vertical supports and the underside of horizontal structure should bring clarity to which event happened at which buildings. This would make the reconstruction of events more focused and productive.
liam

@liamdavis:
Thank you very much for that information. Very much looking forward to your analysis and what you can tell us about the various events at each of the buildings!

It is hard to escape the conclusion that water flashing to steam occurred at Bldg 3 and that the source of the explosion in Bldg 4 had to ultimately be the spent and un-spent fuel in the SFP.

Thanks AntonL!

Oyster Creek Reactor Building General Arrangement (approx. 1 MB)
http://i.min.us/ikukv6.jpg

Oyster Creek Reactor Building Refueling Level (approx. 5 MB)
http://i.min.us/ikum3E.jpg

The second pic shows a lot of little details, such as the height of the 4 reactor cavity shield plug slabs being 7 feet (2.13 meters). Note that the differences between the Oyster Creek plant and the Fukushima reactors are quite possibly non-trivial. It would be really nice if TEPCO would release a set of drawings but I don't think that's going to happen.

I'll find the URLs for the PDFs I have of the Oyster Creek drawings. There are 4 PDF files totalling about 23 MB. Hmmm... now that I think about it, there are no direct PDF download URLs, you'll have to navigate an NRC website to get to them. I'll post how to do that tomorrow.

I spent more than a few hours searching for reactor building blueprints on the NRC site, and the ones for Oyster Creek are the only ones I could find. Others haven't been scanned into PDF form yet, and still others are, I think, not publicly available at all. That's too bad because I believe the closest reactors in the US to the Fukushima Daiichi ones are the ones at Vermont Yankee and (now closed) Millstone I.

@MiceAndMen:

Thank you also for the detailed drawings of the reactors. The last in particular gives some excellent details on the "likely" construction of the upper containment including the shield plugs (which as it turns out) are clad in carbon steel -- at least at the Oyster Creek facility.

As above, flashing of water to steam seems at least to me to be what occurred in part at Unit 3. It also seems likely that the initiating event was an explosion occurring in the primary containment. How to get from "A" to "B" is a question that I don't think has been answered fully.

As for Unit 4, the shattered upper mast of the FHM seems to indicate a violent event in the SFP with lots of energy transferred to the mast, but perhaps not so much damage to the remainder of the FHM. And additional plans detailing what might have been directly behind the blown out panels at the north and south face of Bldg 4 would be most interesting.

@all:
Coming at the explosion in the lower building, here's a hypothetical question for someone who knows reactors:
In the myriad of pipes, tanks and accessories hooked up to the RPV and primary containment and housed outside of the RPV and primary containment, in the lower building (other than the torus suppression pool), are there any of them that might explode as a direct result from over-pressure, steam or hydrogen accumulation inside the primary containment or RPV?

 

[artax]

if anyones interested

latest drone photos here

http://www.cryptome.org/

dr dodge

Nice one!

not read the last 20 pages but there's a good situation update here:-

http://cryptome.org/0003/daiichi-assess.pdf

I know there are translation problems, but I just love the way they say "unit one is relatively stable"!

Relatively! ... to what!

 

[Borek]

I simply said that I wanted to estimate its mass if we were able to calculate the energy involved during the explosion as I know the height at which these items have gone up.

No matter how many times you will repeat it, the answer will be still the same - you are trying to do thing that is impossible.

I suggest you open a new thread in the General Physics subforum, as this discussion is OT here.

 

[|Fred]

You can not trust any of the readings/reports. Because it's TEPCO and the press most of the time do not know what they are writing about

I won't go as far as giving 100% trust to tepco's number has they have been proven wrong, but I would not comment on TV press report that more often than not, are misleading.

 

[artax]

Hello, I've been lurking here for the last month. I was happy to find a place where people actually knew what they were talking about. For that, thank you.

I found a Tepco press site with images and videos, some that I have not yet seen on any other sites.
http://www.tepco.co.jp/en/news/110311/

I found the "Sampling in Spent Fuel Pool of Unit 4" video very interesting. I was surprised it is in such good shape, at least to my "not-a-scientist" eyes.
http://www.tepco.co.jp/en/news/110311/images/110414_1f_1.zip

If you have already seen these, I apologize and I will go back to my lurking.

Excellent link thanks!

 

[TCups]

Nice one!

not read the last 20 pages but there's a good situation update here:-

http://cryptome.org/0003/daiichi-assess.pdf

I know there are translation problems, but I just love the way they say "unit one is relatively stable"!

Relatively! ... to what!

The status report is dated 26Mar. Is there a more recent version of this document?

 

[Krikkosnack]

http://nige.wordpress.com/2011/03/1...-fukushima-dai-ichi-nuclear-reactor-number-1/

the overpressure-impulse from an air burst 1 kiloton or 1,000 tons of TNT equivalent nuclear explosion is only 10 kPa-sec or 1.4 psi-seconds at 100 metres and varies inversely with distance, 200 psi-seconds or 1.4 MPa-seconds of overpressure impulse (which Dr Conrad V. Chester of Oak Ridge National Laboratory calculates is needed to rupture the steel pressure vessel containing a nuclear reactor core) requires the distance between the steel reactor vessel and the 1,000 tons of TNT explosion to be just 0.7 metre (70 cm). This blast overpressure impulse can’t arise from a hydrogen gas explosion; there simply isn’t enough energy available!

 

[artax]

How thick is the containment vessel? And what's the temperature difference across it (inside to outside)? I'd guess that the thickness of the steel doesn't matter much relative to the (probably low) heat transfer coefficients at the inner & outer surfaces.

Early on I heard a value of six inches, or 150mm, but I later heard 100mm thick, however the thermal conductivity of steel would mean temperature of insid and out would be the same unless there was a very rapid temp change and you took measurements within a few tens of seconds.

 

[artax]

The status report is dated 26Mar. Is there a more recent version of this document?

They're undoubtedly doing a lot of work vetting/editing/sensoring any info or data before releasing to general public. this is what is so annoying... and why we're all on here.

 

[artax]

I'll start a new attempt to raise awareness for an annotated picture posted before:

The annotation characterizes the curved deformation as damage from heat. Isn't that plausible? Do we have any reliable information on the sequence of events in No4 (fire before/after explosion)

@TCups, you posted the picture, You remember where you got it?

Hey Tcups, I was discussing this with my Dad a while back and he immediately suggested that the roof bowed upwards in the explosion bending the girders and pulling the walls in at the top.

PS sorry for all these posts, just been away and not read anything for days! (only have t'internet at work)

 

[TCups]

Hey Tcups, I was discussing this with my Dad a while back and he immediately suggested that the roof bowed upwards in the explosion bending the girders and pulling the walls in at the top.

PS sorry for all these posts, just been away and not read anything for days! (only have t'internet at work)

Hmmm . . .

The northeast corner of Bldg 4 is odd, for sure. I don't believe it was the whole roof that lifted -- maybe the northeast corner might have had that effect. But if so, why?! What happened in the northeast corner of that building.

@liamdavis:

Maybe you could lend your expertise here, sir. Also, can you comment on your assessment of the possibility that the concussion and shock wave from the Bldg 3 explosion might have done structural damage to the northeast corner of Bldg 4 that wasn't readily visible from the outside. Perhaps after the blast at Bldg 3, the northeast corner of Bldg 4 was simply the weakest link.

 

[PietKuip]

Early on I heard a value of six inches, or 150mm, but I later heard 100mm thick, however the thermal conductivity of steel would mean temperature of insid and out would be the same unless there was a very rapid temp change and you took measurements within a few tens of seconds.

The thermal resistance of such a length of steel is quite high, you can keep one end of a steel rod in your hand while the other end is hot. Also, the content of the RPV has a large heat capacity. Flooding the outside with cooling water is not an effective way of removing the heat generated inside. I am too lazy right now the look up the numbers (what thermal power is supposed to be generated a month after scramming, the surface area of the RPV, the thermal conductivity), but my gut feeling is that the equilibrium temperature inside would come out too high if this were the only method of cooling.

Maybe the want to flood the drywell because there are holes in connections that are at or below the level of the fuel rods? Holes that prevent increasing the water level?