Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[jim hardy]

Astro - here's another European study of criticality on reflood... a lot like SARA . they also mention computational instability so maybe their computer codes don't do so well on these.. perhaps a job for analog computers ?? (just kidding, I'm real old school)
http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/28/059/28059598.pdf

It mentions possibility of periodic power excursions which sounds a lot like phrases in early news reports about a reactor that 'spat steam'.

 

[jim hardy]

thank you Zilla.

It is a work in progress. i hope to get it cleaned up enough to make it readable.

The shadowy "snaggletooth apparition" shows up a lot of places. It might be worth the trouble to train your eye to see it. but i apologize for the tedious instructions - will clean them up. Takes ten minutes now, more if you upload the hi-res pics linked.

the other one is much shorter , http://www.scribd.com/doc/55960157/MyLastFukushimaPhoto

They're both accessible at http://www.scribd.com/jim_hardy_9

jim

 

[jim hardy]

@ Westfield:

Your photos have incredibly good quality. I'm not that good yet.

I believe the yellow "tank" you pictured in your unit 4 photo IS the reactor containment cap..that's just where it sits in the drone photo, if I'm not turned around, in NW corner.

i believe what i circled is further back and below that object you highlighted - i think i am seeing the round thing at lower left corner of your yellow rectangle , now covered with mud from rain and helicopter water drops..my unit 3photo shows only a little bit of its top.
Here it is in a March 16 picture of rubble pile before it got all covered with mud.
Two things are circled in red. Upper right is i think vessel cap, other is vessel head. Cap is obscured by a tree, that's why it looks broken.

i think the object you highlighted is the yellow-ish rectangle to right of my upper red circle .

I apologize for low quality. to get hi res see my longwinded writeup "A Couple Fukkushima Photos" at scribd < http://www.scribd.com/jim_hardy_9 > but just skip to last page where i give links to hi-res zip file.

the pictures are so blurry it's not possible to strongly assert anything.
Only reason i mention it is two photos from different angles generally agree.

and if the pressure readings from plant are true, it's not a possibility.
Still if you look at he radiation surveys of the plant there's a "hot" piece of rubble right where i have head. If it were something light surely they'd have moved it by now.

here's what a head looks like from underneath

and you see how perfectly round the lower object is.

compare this picture to survey maps...

sorry guys i didnt mean to hog the board here. Will be quiet now.

old jim

 

[~kujala~]

Somebody asked earlier what is the importance of this new leak from the waste disposal facility.

As far as I see it we must see the whole picture. There has probably been high-level leak from units #1 - #3 to groundwater for 2 months and medium-level leak from unit #4 to groundwater for 2 months also. At the current moment the leaks from #3 and #4 seem to have a significant decline:

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110526e4.pdf

The leaks from #1 and #2 are decreasing also.

Nevertheless, even if there was a new leak from the waste disposal facility and even if this leak would end up in groundwater (which at the current moment seems not to be happening) this leak would not mean a lot compared to what already has happened. The same applies to the leaks into the sea. They had mega-leak from unit #2 pit into the sea and now this leak has been plugged. It's probably impossible to have a leak having such enormous contamination anymore.

The much bigger problem, as I see it, is TEPCO's calculations about the water they have to move from the reactor/turbine buildings outside.

TEPCO has perhaps calculated their estimates based on the water that has accumulated in the turbine/reactor buildings. They have also calculated the amount that is going to accumulate because they are feeding new water all the time.

But has TEPCO taken into account the possibility that tsunami waters have increased the surface level of groundwater? Even if they were able to transfer all water in the turbine/reactor buildings today, tomorrow there could be more water in the reactor/turbine buildings because groundwater could leak in.

I think what they should do is to hire a couple of groundwater specialists who would try to calculate the following things:
- How much water did tsunami left in the plant area?
- How much did the surface level of groundwater increase after tsunami (if any)?
- How much water are we going to expect in the plant area from the rains? Rain water infiltrates into the ground and eventually reaches groundwater and because groundwater is polluted rain water will also be polluted.
- How much time is it going to take for this elevated groundwater to reach again its normal level?
- What is the maximum amount of groundwater that could leak into the reactor/turbine buildings and that could accumulate in the sub-drain pits?

Then they should increase their evaluation of needed storage capacity by the maximum amount of groundwater that could still leak into the turbine/reactor buildings and by the maximum amount of water that could accumulate in the sub-drain pits and has to be emptied. They should assume worst-case scenario and so from there everything that turns out not to be so bad would be a good thing indeed.

Anybody wants to try to calculate the total amount of water that should perhaps be taken into account?

Edit: The good thing is that after a while (perhaps 1 or 2 months from now on) all groundwater will be low-level contaminated. And after that one possibility is that this low-level contaminated water will be directly pumped to the sea as far it accumulates in the reactor/turbine buildings and sub-drain pits. Time is on TEPCO's side!

 

[NUCENG]

On Mamoru's layout plan for Fukushima Daiichi unit 3 at http://3.bp.blogspot.com/-JaxFid8Qo...AAko/t5TVRl5sb-4/s1600/R3++completa+small.jpg there is a white rectangle a few steps south of Diesel engine 3A called (in Italian) "boccaporto cisterna carburante" (Fuel tank hatch). So, my understanding is that the fuel tanks used by the diesel generators are located there, underground. If they can withstand the pressure from the water during the flooding and if the air intakes are located high enough, these tanks are probably OK.

Fuel tanks are vented and have transfer pumps. Seawater contamination of fuel would render the fuel unusable until it can be separated. That requires power. Fuel transfer pumps could also have been damaged and not visible in the images.

But I agree underground fuel storage tanks are probably intact.The generators all died about the same time (1545 or so). They were probably running on fuel in their local day tanks.

We know that two employees were killed inside the turbine building during the tsunami. Water entered the buildings. If the air cooled diesels were located above the water damage, that points to the switchgear, breakers, and electrical distribution centers that connect the generator output to the safety equipment. Flooding those electrical panels would trip the diesels, including air cooled generators. The electrical damage would also have prevented using intact diesels after the tsunami was gone.

 

[tonio]

@ Westfield:
I believe the yellow "tank" you pictured in your unit 4 photo IS the reactor containment cap..that's just where it sits in the drone photo, if I'm not turned around, in NW corner.
old jim

I looked for your "yellow tank" on an aerial photo of R3 and I believe I have found it. I compared its dimensions with the yellow reactor cap visible in R4. It seems to have about half to two-thirds of the size of the R4 cap, thus it seems to be something else.

 

[ascot317]

...Rod drop accidents are a concern because they insert positive reactivity into the core which if uncontrolled can result in a burst of power to the point were the fuel and core are damaged, which is both a safety and economic concern...

Astronuc, I've always wondered why these BWR's use bottom feeding rods in the first place.

From a safety point of view this is the most challenging. I know how they have designed the system to be "fail safe", but why make it harder and riskier than it has to be?


If this suggestion would have gone over my desk without really good arguments, I'd probably start questioning the mental state of my planners.

The only reason I can see is making loading from the top easier.

 

[NUCENG]

Astronuc, I've always wondered why these BWR's use bottom feeding rods in the first place.

From a safety point of view this is the most challenging. I know how they have designed the system to be "fail safe", but why make it harder and riskier than it has to be?


If this suggestion would have gone over my desk without really good arguments, I'd probably start questioning the mental state of my planners.

The only reason I can see is making loading from the top easier.

The whole idea in a BWR is to boil water in the core. That steam is very "wet" and would damage a turbine if used directly. At the top of the RPV there are steam dryers and separators to improve steam quality. That prevents using top inserted rods. The hydraulic control rod drive mechanisms CRDMs are therefore at the bottom of the RPV. If unlatched, rods drift into the core under the driving force of reactor pressure. In a SCRAM high pressure water forces them into the core in a few seconds.

 

[clrcdd]

this document might be of interest in regard to recriticality in BWRs
http://bit.ly/mpxlJB

source:
http://www.sciencedirect.com/science/article/pii/S0029549301003922

 

[tsutsuji]

Does this fall into the good or the bad news category? No leak into groundwater is surely good, but there wasn't supposed to be any kind of leak, I assume? What, if anything, does it tell that also the wastewater facility leaks somehow?

They said : "Cracks in floors and other surfaces were subject to on-site examination, and every visually-identified crack was confirmed to have been repaired with polymer cement waterproof coating" : http://www.nisa.meti.go.jp/english/files/en20110520-2.pdf

http://www.yomiuri.co.jp/science/news/20110527-OYT1T00712.htm says that the interstices at the door between the Miscellaneous solid waste volume reduction treatment building (incinerator building) basement and the corridor had been filled with resin as part of the "making more watertight" job, but that was obviously "not sufficient"...

The corridor dimensions are 70~80 x 4.5 x 4.5 m.
The water level there was 2.2 m on May 26th
Radiation at the surface of the water was 70 mSv
A detailed map is available at http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110527_01-e.pdf

The water level at the Miscellaneous solid waste volume reduction treatment building (incinerator building) decreased by
20 mm between May 25 7:00 AM and May 26 7:00 AM : http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110526_02-e.pdf
58 mm between May 26 7:00 AM and May 27 7:00 AM : http://www.tepco.co.jp/nu/fukushima-np/images/handouts_110527_02-j.pdf

 

[jlduh]

Somebody asked earlier what is the importance of this new leak from the waste disposal facility.

As far as I see it we must see the whole picture. There has probably been high-level leak from units #1 - #3 to groundwater for 2 months and medium-level leak from unit #4 to groundwater for 2 months also. At the current moment the leaks from #3 and #4 seem to have a significant decline:

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110526e4.pdf

The leaks from #1 and #2 are decreasing also.

Nevertheless, even if there was a new leak from the waste disposal facility and even if this leak would end up in groundwater (which at the current moment seems not to be happening) this leak would not mean a lot compared to what already has happened. The same applies to the leaks into the sea. They had mega-leak from unit #2 pit into the sea and now this leak has been plugged. It's probably impossible to have a leak having such enormous contamination anymore.

The much bigger problem, as I see it, is TEPCO's calculations about the water they have to move from the reactor/turbine buildings outside.

TEPCO has perhaps calculated their estimates based on the water that has accumulated in the turbine/reactor buildings. They have also calculated the amount that is going to accumulate because they are feeding new water all the time.

But has TEPCO taken into account the possibility that tsunami waters have increased the surface level of groundwater? Even if they were able to transfer all water in the turbine/reactor buildings today, tomorrow there could be more water in the reactor/turbine buildings because groundwater could leak in.

I think what they should do is to hire a couple of groundwater specialists who would try to calculate the following things:
- How much water did tsunami left in the plant area?
- How much did the surface level of groundwater increase after tsunami (if any)?
- How much water are we going to expect in the plant area from the rains? Rain water infiltrates into the ground and eventually reaches groundwater and because groundwater is polluted rain water will also be polluted.
- How much time is it going to take for this elevated groundwater to reach again its normal level?
- What is the maximum amount of groundwater that could leak into the reactor/turbine buildings and that could accumulate in the sub-drain pits?

Then they should increase their evaluation of needed storage capacity by the maximum amount of groundwater that could still leak into the turbine/reactor buildings and by the maximum amount of water that could accumulate in the sub-drain pits and has to be emptied. They should assume worst-case scenario and so from there everything that turns out not to be so bad would be a good thing indeed.

Anybody wants to try to calculate the total amount of water that should perhaps be taken into account?

Edit: The good thing it that after a while (perhaps 1 or 2 months from now on) all groundwater will be low-level contaminated. And after that one possibility is that this low-level contaminated water will be directly pumped to the sea as far it accumulates in the reactor/turbine buildings and sub-drain pits. Time is on TEPCO's side!

Without having a detailed mapping of the underground area and water table, including data from piezometers (small wells to measure underground water level) with possible seasonal variations, i think it will be very difficult to answer your questions. Still, i already partially answered one concerning the rain water, i got very few comments on the number i gave but you can still read the post... if i find it again (don't find it, hope it has not been deleted...)

I was calculating that with an annual rain height of 1250mm, based on the seasonal curve and with the rainy season coming, over an area of 400m x1000m which is an estimate of the main area that is scattered with debris (and so is contaminated), it will sum up a total of aroud 250 000 tons of rainwater in the next few months (and 500 000 tons for the complete year) that will wash this mess and will finish in the ocean for the main part (don't forget that there is a rainwater collection system for the plant, we don't know how this system is designed and how many outputs towards the sea there are, but I'm pretty sure this goes to the sea anyway because it is not supposed to be radioactive in normal conditions).

For the water in the basements, you have to understand that any flow comes from a differential of local hydrostatic pressure, even minimal. So as the basements are below ground water level (by how much, that is THE question), the direction and amount of the flow (inward or outward, from the basement standpoint) is depending of the relative height of water inside the basement and water outside of it (water table). Of course if the basement is fully waterproof, then no flow, but this is not the case (N°5 and N°6 have flows from the watertable it seems, which may have moved up as you said with tsunami). So what I foresee is the possibility that when the basements where almost empty (with regular pumps ejecting out the inflows from the watertable, which was probably routine operation to keep these basements dry), then of course the direction of flow was from outside to inside (because of hydrostatic differential). When the basements are filling in with water, the differential is reducing and eventually, this differential can be inverted if water level inside basement becomes higher than water table level outside. Then the flow will invert also, and so leakage from basement towards watertable can happen (with contamination).

Things may be a little bit more complex than this but this is the general idea.

For detailed calculations again, this is not possible without reliable data, mapping and computer program.

 

[Borek]

i already partially answered one concerning the rain water, i got very few comments on the number i gave but you can still read the post... if i find it again (don't find it, hope it has not been deleted...)

https://www.physicsforums.com/showpost.php?p=3321203&postcount=8171

 

[jlduh]

Thanks BOREK! You are far better than me to find my posts

By the way i never got one post deleted here without explanation and a mail, so I appreciate this from the moderators and especially you Borek. Let's say it to be clear

 

[NUCENG]

here's a generic refueling photo, shows top of vessel open with head bolts installed. Note circled walkway - vessel protrudes above refueling cavity floor and walkway presumably crosses vessel to containment flange. I think the outer green ring is the bolt circle for containment cap, perhaps NucEng or somebody with BWR experience can correct me.

never mind deck loop it's just a hose..
four white spots must be reflections of ceiling lights.

pls excuse if a repeat.

This appears to be a photo taken during cavity floodup prior to refueling. As indicated by others the cattle chute is visible leading off to the spent fuel pool. The bio-shield blocks have been removed from the cattle chute. The number of people on the refueling machine makes me think it is during floodup. They are probably doing checks to prepare for refueling. The white spots are likely the underwater lamps installed on the drywell walls. The bolting studs you see are for the drywell cap. Inside the cavity there is the reactor vessel head and its bolting ring but they are not visible in the picture.

edit: on second guess those white spots may be reflections of lights. The perspective of the lights appears wrong for them to be mounted on the drywell wall, especially the one closest to the camera.

 

[tsutsuji]

One can catch a glimpse of a diagram detailing the water treatment facility on the following video of an interview of Areva Japan's president : http://news.tv-asahi.co.jp/news/web/html/210527034.html . The schedule for the launch of the facility has been postponed to mid-June. The delay is caused by some other manufacturers involved in the project.

The projection of dust fixating coating on the reactor and turbine buildings is starting today. It is important to have this done before the heavy "tsuyu" rains start pouring. http://www.tokyo-np.co.jp/article/national/news/CK2011052702000195.html?ref=rank

 

[jlduh]

The projection of dust fixating coating on the reactor and turbine buildings is starting today : http://www.tokyo-np.co.jp/article/national/news/CK2011052702000195.html?ref=rank

According to http://www.nikkei.com/news/category...39F9FE2E2E2E2;at=DGXZZO0195165008122009000000 it is important to have this done before the heavy "tsuyu" rains start pouring.

Yep, if you meditate a bit on the numbers i gave in the post above for rainwater volumes that this area will receive in the next months, we understand why they are so concerned to do this before.

But the question is how good is this product to resist heavy rainwater falls?

Read also here:

http://www3.nhk.or.jp/daily/english/27_02.html

Antiscattering chemical to be sprayed on buildings
The operator of the damaged Fukushima Daiichi nuclear power plant will spray an anti-scattering agent onto its buildings to prevent radioactive dust from spreading.

[...]

The chemical hardening agent selected for the task is usually used to contain asbestos.

[...]

Tokyo Electric Power Company says it will use two fire engines to spray the chemical onto building walls. However, TEPCO says it cannot spray all the walls because debris still blocks access to some area.

[...]

However, the chemical won't be applied to all areas because if it gets inside the pool that contains spent fuel rods it might interfere with the circulation of cooling water.

The forecast for the coming 5 days in fukushima area is a total of around 110mm of rain, which translates to 44 000 tons of water in my reference area of 1000m x 400m. Not a bird pee...

http://www.weather-forecast.com/locations/Fukushima/forecasts/latest

 

[zapperzero]

Yep, if you meditate a bit on the numbers i gave in the post above for rainwater volumes that this area will receive in the next months, we understand why they are so concerned to do this before.

But the question is how good is this product to resist heavy rainwater falls?

It's polymer glue. It will hold. Maybe some will be blown or scraped off in high winds, but that's all.

 

[Rive]

It's polymer glue. It will hold. Maybe some will be blown or scraped off in high winds, but that's all.

It'll hold only while there is something ~solid beneath, and it can do nothing with any water coming from outside the sprayed area.

I'm worried and expecting problems.

 

[tsutsuji]

The last sentence of http://www.tokyo-np.co.jp/article/national/news/CK2011052702000195.html?ref=rank says that they've already spread this dust-fixating coating on the ground in a number of places since the last decade of April, but they subsequently discovered that new dust originating from the walls of the buildings was depositing again on the coating.

 

[MadderDoc]

<..> If you have fifteen minutes to kill, and promise to not accuse me here of fearmongering , i welcome your comment at this link, or about it here:
http://www.scribd.com/jim_hardy_9<..>

The first 'leg' of your contention, that it is possible to 'see' that unit 3 reactor/containment caps are missing is exceedingly likely due to an illusion.

Because, it is exceedingly likely that what you _do_ see when looking at that area of the top of the building is largely the imprint of the overhead crane waggon, sitting on top of the two huge overhead crane traversal beams.

Here is a markup side by side, of the unit 3 rooftop, and a photo detail from unit 3 before the disaster showing the overhead crane parked close to the south wall of the building:

During the explosive events the overhead crane fell to the floor, ending up with its beams spanning across the reactor area, with the crane waggon crashing close to its center. These huge objects now very effectively block the view to the area underneath them, exactly there where the reactor shield and caps were situated in the intact reactor building. So, from mere inspection of this area in photos very little can be said about the current position and intactness of the shield plugs, and the RV and CV caps.

 

[jlduh]

It'll hold only while there is something ~solid beneath, and it can do nothing with any water coming from outside the sprayed area.

I'm worried and expecting problems.

Plus, as said in the article, the debris make the opeartion very complex. If you think about the developped surface of all the debris lying one over the others in a big pile of mess, this surface is huge, and to be covered the glue has to go into all these cavities below the steel mess to avoid being wash by the heavy rain, which is probably less viscous.

So for sure it will reduce for some time the amount of dust released and washed away but I woud be very interested to now the real mid-term efficiency of this process.

Covering it with a plastic protection will be more effective, but that's an other story to do it...

EDIT: i don't know if this product is related to this japanese patent (quite surprisingly, it seems to contain boron, even if it was developped for asbestos antiscattering):

http://pat365.com/patent/patentContent.jsp?pID=JP2010019051&patType=%E7%A1%BC%EF%BC%9B%E5%85%B6%E5%8C%96%E5%90%88%E7%89%A9%26nbsp;Boron%26nbsp;Compounds%26nbsp;thereof%26nbsp;#

 

[elektrownik]

new picture of unit 3 with iaea team: http://www.tepco.co.jp/en/news/110311/images/110527_3.jpg
On the left we can see 2nd fuel machine, and big crane in center

 

[GJBRKS]

new picture of unit 3 with iaea team: http://www.tepco.co.jp/en/news/110311/images/110527_3.jpg
On the left we can see 2nd fuel machine, and big crane in center

Close-up of area :

http://inkers.nl/uploads/reactor-3.JPG

 

[Rive]

new picture of unit 3 with iaea team: http://www.tepco.co.jp/en/news/110311/images/110527_3.jpg
On the left we can see 2nd fuel machine...

https://www.physicsforums.com/showpost.php?p=3293994&postcount=6467" :-)

 

[zapperzero]

Plus, as said in the article, the debris make the opeartion very complex. If you think about the developped surface of all the debris lying one over the others in a big pile of mess, this surface is huge, and to be covered the glue has to go into all these cavities below the steel mess to avoid being wash by the heavy rain, which is probably less viscous.

Which is why they will only really spray the walls and other reasonably flat surfaces.

 

[PietKuip]

this document might be of interest in regard to recriticality in BWRs
http://bit.ly/mpxlJB

source:
http://www.sciencedirect.com/science/article/pii/S0029549301003922

This article considers the case where electrical power and water is restored during the time window between the melting of the control rods and the melting of the fuel rods.

It does not seem that something like that occurred at any of the Fukushima reactors.

 

[jlduh]

https://www.physicsforums.com/showpost.php?p=3293994&postcount=6467" :-)

yes, it has already been discussed here and this looks like the machine that tensions the studs, this is even clearer with this view. This is what Jim was identifying as the RPV cover, but this is not.

We have also a better view over the yellow part that Jim proposed to be the containment cover but to me, it seems more to be a concrete part with some clear (and maybe yellow?) color...

 

[jim hardy]

@ Tonio --

THANK YOU for your interest! And your kind reply.

I looked for your "yellow tank" on an aerial photo of R3 and I believe I have found it. I compared its dimensions with the yellow reactor cap visible in R4. It seems to have about half to two-thirds of the size of the R4 cap, thus it seems to be something else.

we are real close together, Mr Tonio. I am looking NORTH of that cockeyed vent pipe on roof, you are south. Right hand edge of your rectangle goes over my object.

Here it is on a March 16 photo, very slightly different angle.. I put a rectangle around it like you did. Note relation to vent pipe.
It gets obscured in later photos. Small wonder with all the rain and smoke , not to mention the aftershock tremors of 18th.

yours is much higher quality than mine, i don't have knack yet.
Mine is in the zipped folder at
http://cryptome.org/eyeball/daiichi-npp3/daiichi-photos3.htm
and you have to unzip the folder referenced at top of that file
where it says

The 31 originals full-size: http://cryptome.org/eyeball/daiichi-npp3/daiichi-photos3.zip (30MB)

it unzips to a 1.02 meg jpg and i don't know why its so blurry. yours is sharper yet less bytes. After unzipping it's got name aerial-2011-3-18-14-50-0.jpg, one of ~30 photos. I made a folder for them.


do you have the link for your photo?

In the photo above one can plainly see the uncovered hole where reactor plug oughta be.
Later ones look like the hole is covered by crane. I blame that on aftershocks of 18th i think they were, do i recall a 5.5 ?

 

[jlduh]

new picture of unit 3 with iaea team: http://www.tepco.co.jp/en/news/110311/images/110527_3.jpg
On the left we can see 2nd fuel machine, and big crane in center

One is Philippe Jamet, Head, Division of Nuclear Installation Safety at IAEA.
http://www.iaea.org/newscenter/multimedia/videos/safety/npp/jamet/index.html

By the way everything he is saying in this video is a premonition, several month before, of what occurred at Fukushima... The analysis is perfect.

But let's talk about this in the political thread: https://www.physicsforums.com/showthread.php?p=3325284#post3325284

 

[jim hardy]

This article considers the case where electrical power and water is restored during the time window between the melting of the control rods and the melting of the fuel rods.

It does not seem that something like that occurred at any of the Fukushima reactors.

piet the link took me to a place that offers it for $31.50

i downloaded a document by same title here, i think it's a public document
http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/31/025/31025624.pdf

think it might be same one?

for another forum's discussion of recriticaliy , peruse
http://tickerforum.org/akcs-www?singlepost=2541030
it's by a layman but references a couple official documents, and gives links

oops i was going to stay quiet.

over and out for 24.

 

[SteveElbows]

In the photo above one can plainly see the uncovered hole where reactor plug oughta be. Later ones look like the hole is covered by crane. I blame that on aftershocks of 18th i think they were, do i recall a 5.5 ?

Come off it. There is no evidence that the crane & its supporting structure fell later. Pay even half as much attention to photos that actually show stuff clearly as those that do not, and pretty much all of the features that interest you vanish.

Take for example your recent posts about the rubble on north side of reactor 3 building. There were already a number of other photographs which have enabled us to identify some things more clearly, things that don't match your analysis. And todays photos with IAEA delegation and reactor 3 provide further evidence that what you think you might see in the low res shot is not actually there, and no amount of internet discussion will change that. No reactor or containment caps.

 

[~kujala~]

don't forget that there is a rainwater collection system for the plant, we don't know how this system is designed and how many outputs towards the sea there are, but I'm pretty sure this goes to the sea anyway because it is not supposed to be radioactive in normal conditions

Part of rainwater goes also into the same sub-drain pits where groundwater goes through vertical shafts, this is how I have understood this picture (sorry some text only available in Finnish):
http://varasto.kerrostalo.huone.net/salaojat_2.png
(Edit: It depends on whether the vertical shaft has open or closed top.)

As for the area outside buildings I have no clue where it is going. BTW I read somewhere that in modern buildings you should never direct groundwater and rainwater into the same pits as the picture above suggests that is happening in Fukushima.

When the basements are filling in with water, the differential is reducing and eventually, this differential can be inverted if water level inside basement becomes higher than water table level outside. Then the flow will invert also, and so leakage from basement towards watertable can happen (with contamination).

So this might indicate that it would be anyway a good idea to pump as much water from the basements as possible to keep the flow of water outside in.

I still think they should calculate some conservative worst-case scenario for all water that could accumulate in the buildings/sub-drain pits. This way there would be no more sudden surprises if the level of water would be "still rising". Instead they could say that water level is rising "as expected".

 

[AntonL]

new picture of unit 3 with iaea team: http://www.tepco.co.jp/en/news/110311/images/110527_3.jpg
On the left we can see 2nd fuel machine, and big crane in center

It looks like a pre-cast construction method was used for the reactor building, at least for the upper part. That would explain why the columns got toppled that easily.

 

[AntonL]

Gundersen Gives Testimony to NRC ACRS http://vimeo.com/24312973

 

[SteveElbows]

Did some detail get lost in the drama of reactor 3's temperature rollercoaster this month?

I noticed for quite some time that TEPCO updates made it sound like the additional water via the reactor feedwater system was part of a plan to stop using the fire extinction system piping. But as they were clearly having issues trying to bring the temperature under control at the time, I wasnt sure if this was just spin. However, since the various reductions in water injection rate that have taken place recently have targeted the fire line, to the extent that water rate is now down to just 2 m3/h via that particular line, it seems they really are swapping over and this was not just an exercise in getting as much water as possible into the reactor to put the brakes on soaring temperatures.

Do we know if TEPCO have said why they wanted to switch lines? Do we know at what height water emerges from the fire line as opposed to the reactor feed line? Its possible that they think fire line was doing a poor job of cooling 3, or are there other reasons why a switch was more desirable, eg for the longer term?

Example of what TEPCO say about this stuff in updates:

-At 4:53 pm on May 12, as a part of work to switch the water injection
line to the reactor from the fire extinction system to the reactor feed
water system, we started water injection through the reactor feed water
system in addition to through the fire extinction system.
-At 8:52 pm on May 26th, we changed the rate of water injection to the
reactor through the fire extinction system piping arrangement from
approximately 3 m3/h to approximately 2 m3/h.
-The current rate of water injection is approximately 2 m3/h through the
fire extinction system piping arrangement and approximately 13.5 m3/h
through the reactor feed water system piping arrangement .

From http://www.tepco.co.jp/en/press/corp-com/release/11052710-e.html