Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Yamanote]

Well, my point is:
If all the nasty molten fuel stuff has remained inside unit 3's PCV and the gas management system draws off most of the steam, I actually see no other steam release route.

Or did I miss a point?

 

[etudiant]

Well, my point is:
If all the nasty molten fuel stuff has remained inside unit 3's PCV and the gas management system draws off most of the steam, I actually see no other steam release route.

Or did I miss a point?

Afaik, there is no gas management system in place other than at reactor 1.
The reactor 4 structure is getting worked on pretty extensively, mostly dismantleing, but the reactor was empty with the fuel in the SPF, where videos still show it to be.
Reactors 2 and 3 are close to unapproachable and are believed to have suffered PCV damage. Any steam from either is likely to be dangerously radioactive.
TEPCO indicates the current air emissions rate is around 10 million bequerels, so the cooling is not yet fully effective.

 

[zapperzero]

I cannot imagine what that "steam" could be. AFAIK the water processing plant does not use steam. The reactors and basement water should be too cool. I cannot think of a cleaning or maintenance activity that would use steam. Any explanations?

Steam from a reactor, coming out of some broken pipe in a turbine building?
Smoke from a generator or some other big diesel?

 

[CaptD]

I think one or more of the missing Corium(s) are beginning to interact with the groundwater, especially after Earth quakes (EQ's) and that is the cause of the "steam" events that are visible in some of the web cameras...

It would be great to place a recording G-Meter at these locations but TEPCO is not making it easy to do so...

Seeing massive amounts of "steam," (which more correctly should be referred to as "radioactive steam" coming from the ground is something quite different than steam coming from what is left of the buildings IMO.

 

[etudiant]

The angle of view does not provide any idea of where the steam/smoke is coming from.
There are instants that suggest a single source such as a pipe. It could just be a large engine idling in the cold weather.

Corium interactions with ground water seem a minimal threat when the site has been flooded pretty much since the accident.
The location argues against a direct PCV connection, as it is well outside the reactor perimeter.

 

[SteveElbows]

Afaik, there is no gas management system in place other than at reactor 1.

Not sure why you say that, unless we are talking about different sorts of gas management systems. Reactor 2 has had one for months now (thats where the gas sample analysis is coming from for that reactor, Xe133 etc) and reactor 3's started operation on Feb 23rd.

I haven't spent ages studying the video footage but isn't the area in question between reactors 2 & 3, not 3 & 4?

Looking at Tepco status updates covering Feb 28th, there is one operation that could be relevant:

From 8:51 am to 3:45 pm on February 28, according to the investigation on trenches on January 19, 2012, high density contaminated water inside was found inside circulating water pump discharge valve pit of Unit 3 water pump room. Therefore, we started to transfer the accumulated water from the pit to the basement of Unit 2 Turbine Building.

 

[SteveElbows]

Anybody got any comments on the radiation readings, photos or videos of the recent robot activity inside reactor 2 building (mostly 5th floor)?

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120228_04-e.pdf

http://www.tepco.co.jp/en/news/110311/index-e.html

I haven't looked at the videos yet but it was good to see an image of the area above the reactor well, not obscured by barriers this time as they gave the new robot a longer camera arm.

 

[etudiant]

Not sure why you say that, unless we are talking about different sorts of gas management systems. Reactor 2 has had one for months now (thats where the gas sample analysis is coming from for that reactor, Xe133 etc) and reactor 3's started operation on Feb 23rd.

I haven't spent ages studying the video footage but isn't the area in question between reactors 2 & 3, not 3 & 4?

Looking at Tepco status updates covering Feb 28th, there is one operation that could be relevant:

From 8:51 am to 3:45 pm on February 28, according to the investigation on trenches on January 19, 2012, high density contaminated water inside was found inside circulating water pump discharge valve pit of Unit 3 water pump room. Therefore, we started to transfer the accumulated water from the pit to the basement of Unit 2 Turbine Building.

Thank you, the suggestion seems a plausible explanation.
Re gas management, my mistake. I was thinking of the emissions management, which is a different aspect.
Gas management has indeed been ongoing for months at reactors 1 and 2.

 

[zapperzero]

Well this is odd.
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_01.jpg
a large number of pairs of rubber boots are ranged neatly near what seems to be the concrete cap of the reactor well (unit 2). The picture was taken with a robot.
another odd detail in
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_02.jpg
there are bits of what seems to be the SFP guardrail (the remains of bottom panels, to be precise) which seem melted and burnt.
there seems to be some discoloration/soot here as well:
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_03.jpg

 

[HowlerMonkey]

That might be smoke/steam from an internal combustion engine.

I would assume they would eventually repair and start some of the generators or other engine run equipment on the facility with the first start billowing much white smoke.

Just a guess.

 

[Jorge Stolfi]

I haven't spent ages studying the video footage but isn't the area in question between reactors 2 & 3, not 3 & 4?

Indeed, my mistake.

 

[r-j]

http://youtu.be/fimRJocH_90

This video talks about cracks in the soil at the plant. Which started after earthquakes. Has there been an earthquake near there of late?

 

[denislaurent]

Well this is odd.
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_01.jpg
a large number of pairs of rubber boots are ranged neatly near what seems to be the concrete cap of the reactor well (unit 2). The picture was taken with a robot.
another odd detail in
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_02.jpg
there are bits of what seems to be the SFP guardrail (the remains of bottom panels, to be precise) which seem melted and burnt.
there seems to be some discoloration/soot here as well:
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_03.jpg

Plus some kind of photoshopping ... http://www.gen4.fr/blog/ (french)

 

[shadowncs]

Well this is odd.
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_01.jpg
a large number of pairs of rubber boots are ranged neatly near what seems to be the concrete cap of the reactor well (unit 2). The picture was taken with a robot.
another odd detail in
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_02.jpg
there are bits of what seems to be the SFP guardrail (the remains of bottom panels, to be precise) which seem melted and burnt.
there seems to be some discoloration/soot here as well:
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_03.jpg

From the curvature of the panels in PIC 2 as well as from the position of the FHM in PIC 1 (present in PIC 2 on the right) I'd say those guardrail panels are the top of reactor guard panels (also visible from the other side in PIC 1)

 

[Jim Lagerfeld]

Plus some kind of photoshopping ... http://www.gen4.fr/blog/ (french)

I'm intrigued, that sure is some shoddy work with the clone stamp! And the comparison with the low-res video-cap from the same spot proves that it is not an honest stitching artifact but rather a shoddy attempt at removing something from the hi-res image.

 

[Atomfritz]

Well this is odd.
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_01.jpg
a large number of pairs of rubber boots are ranged neatly near what seems to be the concrete cap of the reactor well (unit 2). The picture was taken with a robot.

And the trash bags lying around... looks like a messie's home.
A German bakery would be closed if regulators found such a mess at the workplace.

Edit: Look at the end of the rail in the lower left of the image. Looks somehow unusual, rail transiting into concrete seamlessly, making me think of photoshop.
Edit2: Thanks denislaurent for the link, there is even more of strange details that I find somehow suspicious.

another odd detail in
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_02.jpg
there are bits of what seems to be the SFP guardrail (the remains of bottom panels, to be precise) which seem melted and burnt.

The concrete (dis)coloration indicates that condensation happens here up to saturation.
To me the crane rails seem thoroughly rusted. I think they will have completely crumbled in a few years if nothing protective is done, making the recovery of the spent fuel using the old crane impossible.
IMO Tepco should grease them with water displacer asap to avoid complicarions like this.

there seems to be some discoloration/soot here as well:
http://www.tepco.co.jp/tepconews/pressroom/110311/images/120228_03.jpg

I am not sure if soot.
High humidity and discolorations concentrating in lower parts, where main condensation occurs.
Black fungus thrives in the Chernobyl sarcophagus in extremely radioactive areas, why should this be different in Fukushima?
Looking closely, mostly organic surfaces (plastics and paint) seem discolored, and these are preferred by fungi.

 

[timid3000]

Plus some kind of photoshopping ... http://www.gen4.fr/blog/ (french)

If you look at the video (3:08), you can see that some kind of error occurred while taking the picture (look at the screenshots I attached).
The idea of photoshopping a picture they are not mandated to release in the first place sounds weird to me, especially when the "hidden" area seems to only contain a piece of paint that fell off from somewhere.

 

[jmelson]

And the trash bags lying around... looks like a messie's home.

Oh, come on! This is a building that was subjected to a powerful earthquake,
then a mil-level explosion!

I think they will have completely crumbled in a few years if nothing protective is done, making the recovery of the spent fuel using the old crane impossible.
IMO Tepco should grease them with water displacer asap to avoid complicarions like this.

Any use of the main crane or the FHM is pretty much out of the question.
If the earthquake didn't damage the support rails, the explosion would have.
Unless the rails were tested very thoroughly and re-surveyed by millwrights, the
crane could fall off the rails the first time it was moved, adding major complications
to any recovery. Massive corrosion is probably going to be a problem in the
disassembly of the plant, though, you are right. The Quince displays show
9 C and ~75% RH, which is a bad situation.

Jon

 

[zapperzero]

Looking closely, mostly organic surfaces (plastics and paint) seem discolored, and these are preferred by fungi.

The panel closest to the camera seems to be missing altogether - which is why I thought fire in the first place.

 

[zapperzero]

Oh, come on! This is a building that was subjected to a powerful earthquake,
then a mil-level explosion!
Jon

Excuse me, what explosion would that be? Afaik, there was a blast somewhere in the vicinity of the torus (5 levels down) and the concrete plug of the reactor well seems to be in its place so I don't think the torus breach could have very much bearing on whatever happened to those panels.

Also, this deck is supposed to have remained untouched by humans ever since the accident. I do not understand the boots, but if they are there since the earthquake, well... why would other stuff be strewn about willy-nilly? Remember that unit 2 is the one with the roof still intact.

 

[Rive]

Excuse me, what explosion would that be?

There was no explosion, true: however judged by the survey map of the level there was something coming up around the concrete plug of the reactor, and I think it's safe to assume that it wasn't cold nor careful.

Boots and the pink plastic bags/sheets: as I remember to the pre-accident tour pictures such things are often used during any activities on the top floor - for example for a refueling operation practically the whole site is wrapped up. We don't have any information about what was in progress right before the accident happened.

 

[duccio]

I'm intrigued, that sure is some shoddy work with the clone stamp! And the comparison with the low-res video-cap from the same spot proves that it is not an honest stitching artifact but rather a shoddy attempt at removing something from the hi-res image.

As they have released also the unedited video, I doubt there is a big conspiracy plan behind. What I'd bet had happened, is the PR guy/webmaster/poor young engineer responsible for drafting press releases and hand-outs, was told to get 3-4 shots out of the video, clean them up as best as he could and make a pdf out of it. If you notice, exposure, light, color also change in the pictures, that are brighter and more detailed than the video (video is so dark that it's even difficult to spot the boots). Trying to clean up the pictures, he probably overdid here and there

 

[Atomfritz]

Regarding the strange image distorting/tile duplication which makes the impression of image editing:

I have looked at the video and the image closely trying to find out what could be the reason for this.

Just to save typing I copied my comment on Ex-SKF here:

Now downloaded the video and looked at it closely.
Around 3:10 plus/minus a few seconds there can be taken some more observations.

As Yosaku correctly notes, the image is parted up into 16 tiles, apparently transmitted sequentially, strangely of unequal size (would really like to know the technical reason why the tiles aren't equal-sized).

The image "blacks out" when the radiation counter jumped to about 0.2 sieverts (in 1 meter height? probably then higher near at floor level where the electronics are probably located).

The operator then hastily moved back Quince. I suppose it was a quick reaction to protect Quince 2 from crashing/latching-up because of radiation.

However, what appears strange to me is the discrepancy of the image shown in the video and the high-res image.
But there could be several benign technical explanations for this.
The display on the Quince control panel (showed in the video) is probably a zoomed-down version of the native resolution of the camera image.

But then the question comes up: how came the seamless impression of the duplicate tile which makes the impression of image editing?
If the tile was a simple duplicate as Yosaku assumes, it would be easily recognizable, like a copied-pasted part of the image.

It is probably not that simple.
When you look very carefully at the hires image you get the impression that the lower left tile actually could be sort of averaging overlaying of two tiles.
Technically this could be caused by a line decoder malfunction caused by radiation, leading to two lines being read out simultaneously, mixing/averaging the output.

So I have to retract my suspicion of image editing, as there seems to be nothing of particular importance in the lower-left image tile.

However, one thing can possibly be concluded of this: Quince's electronics radiation resistance probably is around 0.2 sieverts (assuming the radiation counter is located near the electronics)
I fear Tepco has to be very careful to avoid Quince 2 to die soon too.

Any thoughts/comments about this?

 

[Rive]

Any thoughts/comments about this?

IIRC those robots were surveyed much nastier places there, so I don't think that they have so limited radiation resistance.

About the tiles: as far as I know it's a common practice that the operator gets a live video feed with limited resolution only to conserve bandwidth, and he can ask for full resolution still images if necessary. (Maybe this is the explanation of the luminance difference between the video and the picture used for the pdf document.)

The live feed has twenty-some frames per second, it's pretty resistant against any coding- or transmission errors while the still images are more sensitive. Maybe that's all.

 

[radio_guy]

From what I recall reading, the Quince robots can operate in up to 2Sv worth of radiation reliably, I don't think the 0.2Sv measurement could have caused any problems.

I will say I question their choice of the camera lens, it makes for some quite distorted images, maybe it has something to do with radiation resistance?

 

[SteveElbows]

There was no explosion, true: however judged by the survey map of the level there was something coming up around the concrete plug of the reactor, and I think it's safe to assume that it wasn't cold nor careful.

The rather unsteady footage from last September, taken from the opening in the wall of reactor 2, does show stuff rising from that area.

http://tepco.webcdn.stream.ne.jp/www11/tepco/download/110924_01j.zip

As for the boots, we don't know if they were trying to deal with something such as sloshing of water from the reactor 2 spent fuel pool immediately after the earthquake but before the situation got too serious for people to be inside the building.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120302/index.html The inside of the offsite center was shown to the press for the first time since the accident. They saw the large screen supposed to show each reactor's realtime data or predictions of the spreading of radiations, which did not function at all. The phone system supposed to reach each local government's person in charge by pushing a button also did not function because of the blackout. The offsite center had no air filtering system, and the radiation eventually rose to 200 μSv/hour so it had to be evacuated. The Nuclear Safety Commission has a plan to divide offsite centers into two parts. One part would be far enough from the plant, and the other part, in charge of evacuations would be close to the plant. But the final decision has not been taken yet.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120302/1400_ondokei.html On 1 March in the night, Tepco submitted its report to NISA about unit 2's alternative temperature measurements. Thermometers will be inserted through the pipes that connect to the reactor inside. It will be necessary to lower the radiations in the working environment, and in order to solve many still unsolved problems, it might be necessary to design new tools and techniques suitable for working in narrow spaces. If all the conditions are met, the measurements won't start before the end of July. Tepco is also exploring indirect methods, such as analysing the temperature of the water flowing out of the reactor.

http://www.tepco.co.jp/cc/press/betu12_j/images/120302a.pdf The report to NISA : "Correspondence for temperature increase in the lower part of the Reactor Pressure Vessel of Unit 2 at TEPCO Fukushima Daiichi Nuclear Power Station" (Japanese).

 

[tsutsuji]

The 1 March report ( http://www.tepco.co.jp/cc/press/betu12_j/images/120302a.pdf ) is divided into two parts. The first half, down to page 43 is about the plan to install alternative measurement tools. The second half from page 44 to the end is the assessment of existing thermometers.

On pages 88/91 - 89/91 we find a table with the resistance values of each thermometer in unit 2. For example here are the values for TE-2-3-69H2 (Vessel wall above bottom head) :

Regular inspection value : 300.47 Ω
2011.9.29 151.71Ω 0.50
2011.12.1 153.20Ω 0.51 1.01
2011.12.12 151.80Ω 0.51 1.00
2012.1.27 151.06Ω 0.50 1.00
2012.2.13 155.32Ω 0.52 1.03
2012.2.23 173.36Ω 0.58 1.15
2012.2.23 173.10Ω 0.58 1.15
2012.2.24 175.13Ω 0.58 1.16
2012.2.24 175.23Ω 0.58 1.16
2012.2.25 174.02Ω 0.58 1.15
2012.2.26 174.13Ω 0.58 1.15
2012.2.27 173.45Ω 0.58 1.15
2012.2.28 174.74Ω 0.58 1.16
2012.2.29 173.57Ω 0.58 1.15

The rates written after each Ω value (1) are : (2) measured value/regular inspection value ; (3) measured value/lowest measured value. "1.15" means that the resistance rose by 15% between 29 September and 29 February.

A plot with TE-2-3-69H2 resistance (pink) and temperature (blue) values is available page 63/91.

Here is the footnote with the meaning of each symbol in the first column of the table pages 88/91 - 89/91 :

〇　: not assessed as being broken
A1 : not connected to the central control room with a cable (backup sensor. the high radiation in reactor building basement prevents access)
A2 : assessed as being broken during the regular inspections [prior the accident]
B1 : already reported as being broken in the mid term safety report
B2 : newly assessed as being broken (wire cut)
When the measured value is unstable inside a range we wrote down the highest value.

 

[jim hardy]

has unit 3 top floor been covered with something?

 

[tsutsuji]

The 1 March report ( http://www.tepco.co.jp/cc/press/betu12_j/images/120302a.pdf ) is divided into two parts. The first half, down to page 43 is about the plan to install alternative measurement tools. The second half from page 44 to the end is the assessment of existing thermometers.

I translate the last part of the 1 March report's first part, on http://www.tepco.co.jp/cc/press/betu12_j/images/120302a.pdf pages 8 and 9 (what follows is attachments) :

(3) working plan for alternative thermometer equipments

a. Selection of alternative thermometer equipments and sending devices

After making comparative studies of the thermometers that are to be inserted into the pipes connecting to the RPV, and of the devices to perform such insertion, from the perspective of resistance to radiations or maximum temperature, we selected two kinds of metal sheath thermocouples and two kinds of sending devices and industrial endoscopes.

« metal sheath thermocouples »

* A company's metal sheath thermocouple : φ1.0mm×150m (maximum temperature 650°C)
* B company's metal sheath thermocouple : φ0.5mm×300m (maximum temperature 650°C)

« sending devices »

* wiring equipment : φ4.5mm×30m (inserted by hand)
* industrial endoscope : φ4.0mm×30m (inserted by hand. The bending wire on the extremity can be [remote] controlled)

(attachments 5 [page 38/91], 6 [page 39/91])

b. The work's implementation plan and problems

At present, the alternative means having the highest probability of implementation is the one inserting a thermometer inside the jet pump instrumentation line. Based on this, we selected a detailed working procedure and extracted the relevant engineering and feasability problems. Many problems cannot be settled unless a field study is performed, but if at least the following problems are not solved, it will be difficult to perform the work:

« Problems »

* Being able to lower the radiation in the work area to 15 mSv/hour or below
* In order that the RPV gasses do not flow out from the instrumentation pipe that is being cut, we plan to use an engineering method where the pipe inside is frozen (filling it with water) while cutting, but as the distance between the PCV penetration end plate and the closing valve is short (300 mm or less), the working space is narrow. Working must be possible in such a narrow space.

A survey will be performed to find detailed radiation data in the working location. After this, we will plan decontamination and shielding, and the results will be checked on location. Also, we plan to diminish the work risks by testing the frozen cutting method on a mock-up and to develop tools to enable working in a narrow space. Please note that the problems encountered if we use the routes selected as priority level 2 (through the water level gauge line, liquid control system (SLC) differential pressure detector line, or the Traversing Incore Probe (TIP)), will be nearly the same as if we use the jet pump instrumentation line, so we wrote here the detailed plans for the jet pump instrumentation line work as a representative case.

(attachment 7 [page 40/91 - 42/91])

c. Working schedule

The earliest start of work is at the beginning of July, bringing the completion of work at the end of July. The following schedule is based on the prerequisite that the working environment's radiation is lowered to a level where working is possible, that new technologies do not need to be developped (application of existing technologies), and that the conclusions drawn from the mock-up test's results do not require more than simple modifications.

The completion of tasks that have major consequences on the schedule are noted below as "hold points" (HP). We shall pay attention to the completion of each hold point, and in case the conditions are changed, we shall quickly change the plan, and head toward the installation of alternative thermometers within the shortest time as possible. Please note that there is a high probability of performing the priority level 2 works (through SLC, or TIP), so that, if possible, the field studies about those will be performed at the same time as the one for the priority 1 work (through jet pump instrumentation line).

HP1 : field study 1 (checking the working area's radiation and space) : mid March
HP2 : study of engineering method (assess if it is possible using existing technology) : mid April
HP3 : confirm an effective decrease of radiations after decontamination and shiedling : end of May
HP4 : end of the mock-up : beginning of July

(attachment 8 [page 43/91])