Japan Earthquake: Nuclear Plants at Fukushima Daiichi

AI Thread Summary
The Fukushima Daiichi nuclear plant is facing significant challenges following the earthquake, with reports indicating that reactor pressure has reached dangerous levels, potentially 2.1 times capacity. TEPCO has lost control of pressure at a second unit, raising concerns about safety and management accountability. The reactor is currently off but continues to produce decay heat, necessitating cooling to prevent a meltdown. There are conflicting reports about an explosion, with indications that it may have originated from a buildup of hydrogen around the containment vessel. The situation remains serious, and TEPCO plans to flood the containment vessel with seawater as a cooling measure.
  • #12,401
The report seems to be too vague about the radiation levels in unit 1

After approximately 17:19 that day, the shift team decided to go to the 4th floor of Unit 1's R/B to check if a sufficient amount of water was contained or not in the IC condenser tank with a water level gage installed on the side of the tank. The shift team members who were sent to the building did not wear protective masks or protective clothes though they [STRIKE]made other plans[/STRIKE] [had made preparations beforehand(1)] including a check of the gage location. They left the Units 1&2 main control room.When they arrived at the double doors of the R/B approximately 17:50 that day, they found that their dosimeter (GM tube) had gone beyond the maximum value of 300 cpm[29]. So, they abandoned their plan and returned to the Units 1&2 main control room.
http://icanps.go.jp/eng/120224Honbun04Eng.pdf page 124
(1) my translation

The above is quite precise with a measurement (albeit the measurement tool is out of scale). But a few pages further, the report only says :

The shift team decided to quickly make preparations for an alternative method of water injection and went into the R/B and T/B of Unit 1 at approximately 18:30 that day so as to configure a line for injecting water through the FP system to the reactor.
...
When the shift team went into the R/B of Unit 1 and measured the reactor pressure with a reactor pressure gage, the reactor pressure read 6.900 MPa at approximately 20:07 that day.
http://icanps.go.jp/eng/120224Honbun04Eng.pdf page 151

This time they enter the reactor building. Is it because the radiation had decreased ? Is it because they have their protective clothing on ? Or did they decide to enter anyway ? Or did they decide to enter through a different entrance ? If they could enter at that time, why did they not attempt to try again the IC checking mission they had given up at 17:50 ? Why do they give up so easily when the IC is concerned ?
 
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  • #12,402
http://www.nikkei.com/news/category...DE1EBE2EAE1E1E1E2E0E7E2E0E0E2E3E09180EAE2E2E2 On 24 February, Tepco announced that 9 out of 41 unit 2 RPV thermometers are broken. The NISA instructed Tepco to write a report about this by 1 March. On 23 February, one of the unit 2 RPV thermometers had risen, but it is stable now.

http://mainichi.jp/select/biz/news/20120225k0000m040102000c.html On 23 February, one of unit 2's RPV thermometers rose to 50.3°C, but it dropped to 45.8 at 05:00 AM on 24 February. The NISA instructed Tepco to write a report by 1 March on the study of possibilities to use alternative means to measure reactor temperatures. As one of the three unit 2 RPV bottom thermometers started displaying abnormal values at the end of January, and was found to be broken, the RPV bottom is being surveyed by two thermometers.
 
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  • #12,403
This time they enter the reactor building. Is it because the radiation had decreased ? Is it because they have their protective clothing on ?

All i can offer is this speculation:
When they arrived at the double doors of the R/B approximately 17:50 that day, they found that their dosimeter (GM tube) had gone beyond the maximum value of 300 cpm[29]. So, they abandoned their plan and returned to the Units 1&2 main control room.

A GM tube is used only for very low radiation fields, it is useless in even a modest one.
Since that is what they were carrying they must not have expected radiation at the doorway to the building.
Proper procedure would be to return , notify shift supervisor of unecpectedly high field there.
They could have picked up high range instruments and returned, of course.

But if high radiation in that location told operators they needed to look at something else first, then that's what they would have done. I see attention being paid to fire pumps in those intervening pages, and flooded basements, but haven't digested the document yet.

It's a safe bet they were equipped with appropriate survey meters and coveralls and a new plan of action when they returned.

old jim
 
  • #12,404
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120227/index.html [The 3rd mid-long term government-Tepco meeting] was held on 27 February. The multinuclide facility (the one which can remove strontium) will be introduced within the first half of 2012. Additional tanks for 40,000 tons of decontaminated water will bring the storage capacity to 200,000 tons by April. A new endoscope mission will take place in unit 2 during the last ten days of March, with a longer length, with the purpose of finding the PCV water level.

http://mainichi.jp/select/science/news/20120228k0000m040043000c.html According to the Ministry of Economy and Industry, recently the radiation released into the atmosphere by units 1,2,3 was 10 million Bq/hour, which is a decline from the 60 million Bq/hour estimated in December. Tepco tested multinuclide removal with 62 nuclides with a concentration 100 times lower than the legal level. At present 57 nuclides can be removed to below detection level. Using the multinuclide facility, it will become possible to bring the radiations below the legal level for releasing the water into the sea, but a Ministry of Economy and Industry official said "we are discussing with the local inhabitants etc. to decide whether we will actually do it".

http://www.meti.go.jp/committee/notice/2011a/20120223001.html Notification of opening of 3rd mid-long term meetingWorkshop for technical catalog study regarding the development of equipment to remove fuel debris for decommissioning of Fukushima Daiichi Nuclear Power Station, 24 February, at Ministry of Economy and Industry main building in Tokyo :
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01a.pdf Toshiba/Hitachi GE/Mitsubishi Heavy Industries : Main points of the public appeal of Technical catalog proposals
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01c.pdf Agenda
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01d.pdf Agency of Natural Resources and Energy : Technical catalog for equipments toward decommissioning of units 1,2,3,4.
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01e.pdf (English) Tepco : Technical needs as viewed from the site
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01f.pdf Toshiba/Hitachi GE/Mitsubishi Heavy Industries : Technical developments for remote decontamination inside reactor building
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01g.pdf Toshiba/Hitachi GE/Mitsubishi Heavy Industries : Technical developments to find PCV leakage points [main features and picture of a Hitachi-GE underwater remotely operated vehicle are available on page 22/23]
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01h.pdf Toshiba/Hitachi GE/Mitsubishi Heavy Industries : Technical developments to repair PCV
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01j.pdf Toshiba/Hitachi GE/Mitsubishi Heavy Industries : Technical developments to inspect inside PCV
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01k.pdf Vendor list (PCV inspection)
http://www.meti.go.jp/earthquake/nuclear/pdf/120227_01m.pdf Technical catalog example
 
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  • #12,405
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120228/1940_houkokusho.html The "independent fukushima accident investigation committee" has released its report after hearing 300 people such as former prime minister Kan and US high officials. The simultaneous occurrence of earthquake/tsunami with nuclear accident had not been foreseen so that the emergency manual was unusable. Politicians lacked basic knowledge of the legal framework. The response was haphazard and taken in haste at the last minute. Accurate information did not reach the prime minister office. The scientific support framework to advise politicians was too weak. The NISA is not educating safety professionals so that its human resources and ideas are poor. The NISA did not build plans and proposals. Tepco's responses (not being aware that IC is turned off, not starting alternative injection immediately, having troubles with venting) are causal factors of the widening of the accident.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120228/1940_taiou.html According to the "independent fukushima accident investigation committee", prime minister Kan had some merits such as going to Tepco's main office to encourage Tepco not to evacuate (leaving 50 people on the site), but he interfered too much with the site when he managed such things as the size of batteries. His way of releasing information failed, causing distrust among citizens. Japan ignored suggestions that came from abroad after the September 11 attacks. The way of thinking was "as it is 100% safe, why bother to take countermeasures". The safety myth was designed as a tool against antinuclear activists, but it became an obstacle for the government itself, who failed from taking the latest safety knowledge and technology into account.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120228/1110_speedi.html According to the "independent fukushima accident investigation committee", prime minister Kan and 4 politicians said "we did not receive information from the ministry of education and science about SPEEDI (the radiation spreading analysis system) until many days after the accident and ignored its existence until then". Yukio Edano said he heard about it for the first time in the news around 15 March. According to Edano, the reason why there was no information is because the SPEEDI results were thought to be too imprecise, as the radiation figures could not be obtained. According to the committee, SPEEDI was developed and installed as nothing but a trick to buy citizen's confidence.

http://rebuildjpn.org/wp/wp-content/uploads/2012/02/34fc7150633ba79554ff4c9c9d29885a.pdf Press release : The Rebuild Japan Initiative Foundation announces its accident investigation report.

http://rebuildjpn.org/news/998 We had free copies of the report, but we ran out of them after the press conference. We have received requests, but we are sorry not to be able to respond to them immediately. We are studying how to publish it at a cheap price or to make it available on the internet for the general public.
 
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  • #12,406
The fact that loss of batteries may cause spurious fail-safe closure of valves in the pipe lines needed for core cooling in station black-out situations is in my view the single most important lesson that can so far be learned from the Fukushima Daiichi accident. It was not known to the control room personnel of Tepco, but they can hardly be blamed, since this insight seems to be very rare even among the experts in the nuclear field and something certainly worth consideration at every NPP in the world.

As far as I've been able to find out, every BWR plant in the world with an IC - a really good and passive system to ensure the cooling of the reactor in station black out - depends on the battery-powered DC to keep the valves in this otherwise completely passive system opened. And in many cases, the batteries survive only a few hours of loss of AC, so the water reserves on the IC shell side might actually not play any role at all in the time the plant can survive a complete loss of AC.

I see design changes coming, after this issue (brought to attention largely by Tsutsuji-san's translations) becomes truly recognized. It doesn't help to have AC-independent emergency cooling systems, if the pipelines needed to get the water into the reactors can't be kept open in case of emergency.

The same fail-safe issue played a role in two other aspects of the Daiichi accident as well: pressure relief of the reactors and the containments was also prohibitively difficult after the power was gone, and thus reactors 2 and 3 were lost even though the capability to pump fire water existed at the time the RCICs failed.

So in my view, the more information we get, the more it starts to look that it was the loss of DC, not the loss of EDGs that was the fatal failure. And loss of DC is something the nuclear plants have (so far) generally not been designed to manage. I expect this will change in the future.
 
  • #12,407
tsutsuji said:
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120227/index.html [The 3rd mid-long term government-Tepco meeting] was held on 27 February.

All the meeting's documents are now available at http://www.tepco.co.jp/nu/fukushima-np/roadmap/conference-j.html

http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/m120227_05-j.pdf
* Page 3/94 to 6/94 : PCV gas monitoring systems
* Page 7/94 to 10/94 : upcoming endoscope mission in unit 2. The figure on the bottom left of page 9/94 shows the endoscope going below the grating.
* Page 13/94 to 17/94 : plan to increase the reliability of the water treatment facility (adding pumps, lines, air compressor, etc.)
* Page 18/94 to 36/94 : multinuclide removal facility
* Page 37/94 to 46/94 : subdrain decontamination tests
* 47/94 to 52/94 : decontaminated water tanks replacements and increase
* 54/94 : management of debris
* 55/94 to 56/94 : start of harbour sea-floor covering work
* 57/94 to 58/94 : radiation releases from units 1,2,3 PCVs
* 59/94 : improvement of environment surrounding monitoring posts
* 62/94 to 69/94 : reduction of protective measures (mask charcoal filter versus dust filter etc.)
* 72/94 to 74/94 : reactor building debris removal at units 3 and 4
* 75/94 to 78/94 : survey toward debris removal from unit 4 fuel pool
* 79/94 to 85/94 : verification of unit 4 fuel pool integrity
* 86/94 to 90/94 : situation of unit 2 operating floor (with pictures of quince 2 and quince 3)

http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/r120227_10-j.pdf pictures of technical catalog workshop of 24 February on page 5/5
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/r120227_12-j.pdf International symposium on decommissioning of Fukushima Daiichi to be held on 14 March 2012 in Tokyo.http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120228_04-e.pdf Feb 28, 2012 Investigation result by the robot (quince2) on the 5th operating floor of the Reactor Building of Unit 2
 
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  • #12,408
I heard on NPR a few minutes ago that tonight's PBS TV "Frontline" show will be on Fukushima reactors .
 
  • #12,409
jim hardy said:
I heard on NPR a few minutes ago that tonight's PBS TV "Frontline" show will be on Fukushima reactors .

Thanks Jim. I am in a hotel which doesn't have PBS channel. The Frontline story will also be available online at
http://www.pbs.org/wgbh/pages/frontline/view/
 
  • #12,410
tsutsuji said:
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/m120227_05-j.pdf
* 79/94 to 85/94 : verification of unit 4 fuel pool integrity

On page 85/94 there are four measurements of the distance between the reactor well water level and the 5th floor's floor in four locations. The measurements show that the floor is horizontal. It looks like the old "unit 4 is leaning" theory is ruled out...
 
  • #12,411
Since the no fly zone was reduced to 3km on Feb 25th, there has been a lot of fresh aerial news helicopter footage of the plant site run on Japanese TV. Someone has uploaded one of the clearest clips to youtube:

http://www.youtube.com/watch?v=1Vq5TzMvRa4&feature=player_embedded

The presenter sounds particularly surprised by the complete mess which still obscures the spent fuel pool in reactor 3 (from about 1min20s).

I was more surprised by the extent of the new tank farms and waste storage.
 
  • #12,413
jim hardy said:
I heard on NPR a few minutes ago that tonight's PBS TV "Frontline" show will be on Fukushima reactors .

I was impressed with the documentary on Frontline. There was little or no technical content. There was no judgement of pro or anti nuclear position. There was instead an excellent cross section of the human story of the immediate consequences of the Earthquake/Tsunami/Nuclear Accident. The nuclear director of TEPCO and the former Prime Minister described some of the decisions they made. The fisherman who saved his boat but lost a wife and daughter to the tsunami spoke to the choices he made to abandon searches for them to save his remaining daughter. The plant employees described the fatalistic belief that they would die. Firemen and soldiers trying to initiate cooling while the hydrogen explosions were happening. Powerful stuff.
 
  • #12,414
I watched http://www.pbs.org/wgbh/pages/frontline/japans-nuclear-meltdown/ . Sensationalist spin : "the strongest earthquake that struck Japan". This is true in magnitude, but not in intensity. There are precedents of similar or stronger intensities. The picture of the tsunami hitting the cliff south of the plant is impressive. I realize that the much viewed blurry internet video of "tsunami hitting the plant" is actually tsunami hitting the cliff, not the plant. "Tokyo Tepco headquarters were in charge of tackling" : this is a quite short description for the complex emergency headquarters structures involving Tepco but also the national and local administration, the army, firemen, etc. It is the first time I hear about the people searching for tsunami survivors after the order to evacuate was issued. "They improvised". This is partly true. But reading the cabinet investigation report, I think that a number of retrofits learned from the 2007 earthquake in Kashiwazaki Kariwa (seismic-isolated building, and fire trucks) proved helpful. For one part there is improvisation, for one part they are using safety equipments that had been thought beforehand. Sentionalist spin : "Yoshida said he was prepared to send suicide squad". "They knew that they would be exposed but they went in" while the white board actually reads 20 mSv for the fist team, 89 mSv for the second team : this is not a "suicide" level. The timeline with reactor cores starting being cooled after day 8, after the spent fuel pools are refilled by firemen does not seem accurate (the last melt down was that of unit 2 and cooling resumed on the same day on March 15: see heat plot on http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111130_07-e.pdf page 3 (4/22) ). I think the documentary treated the "did Tepco intend to fully evacuate the plant" controversy quite well. The US specialists who says "there was clear indication of fuel damage in the fuel pools" is left uncontradicted.
 
  • #12,415
Fascinating video.
Amazing amount of waste storage. Has anyone graphed the growth of this facillity? It would be interesting to extrapolate the area required over the next 10, 20 years, etc.
How radioactive is the stuff in these containers?
How resiliant are they to further earthquakes and tsunamis?
 
  • #12,416
curious11 said:
Fascinating video.
Amazing amount of waste storage. Has anyone graphed the growth of this facillity? It would be interesting to extrapolate the area required over the next 10, 20 years, etc.
How radioactive is the stuff in these containers?
How resiliant are they to further earthquakes and tsunamis?

Much the largest item is the 'purified' water left over after decontamination, now about 200,000 tons. TEPCO has been refused permission to dump this water, because it still has some residual contamination.
That would give a 30 foot deep lake about 0.6 miles square (8 meters deep and 1 km/side) in 40 years.
Earthquake resistance of the water storage is probably marginal.
 
  • #12,417
People who keep an eye on the Fukushima Daiichi weathercam have often claimed "massive fires" or "massive steam releases" from the reactors which are easily explained as fog, clouds, or low-light-level camera noise

However, this video http://t.co/wa9KXinD , recorded yesterday (feb 28), apparently shows a substantial release of steam from the ground near units 3 and 4, starting at ~00:38. It does not seem to be fog (too low, very localized and persistent). It does not seem to be smoke (disappears instead of just dispersing).

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?
 
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  • #12,418
Jorge Stolfi said:
People who keep an eye on the Fukushima Daiichi weathercam have often claimed "massive fires" or "massive steam releases" from the reactors which are easily explained as fog, clouds, or low-light-level camera noise

However, this video http://t.co/wa9KXinD , recorded yesterday (feb 28), apparently shows a substantial release of steam from the ground near units 3 and 4, starting at ~00:38. It does not seem to be fog (too low, very localized and persistent). It does not seem to be smoke (disappears instead of just dispersing).

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?

The video is sharply accelerated, as is reflected in the speedy passage of clouds and airplanes, so the steam emissions seem more vigorous than they are in reality.
That said, the still ongoing decay is about a megawatt per reactor, so steam on a winter day would not be unexpected.
The location of the emissions does suggest a below ground source not central to the reactor core, which may be worrysome.
 
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  • #12,419
Okaaay... So assuming that a PCV gas treatment system is now in service for unit 3 as well, the released steam must come from the exhaust of this system, right?

Can anybody confirm that the exhaust is located in this area?
 
  • #12,420
Yamanote said:
Okaaay... So assuming that a PCV gas treatment system is now in service for unit 3 as well, the released steam must come from the exhaust of this system, right?

Can anybody confirm that the exhaust is located in this area?

It is not the most obvious location for a gas treatment plant.

Was not the space between reactors 3 and 4 the location of some piece of very radioactive debris, which was later bulldozed over, immediately after the Mar 15 explosions?

Also, was there not some testimony by plant workers about steam coming from out of the ground near the reactors? Which reactor was not clear though.
 
  • #12,421
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?
 
  • #12,422
Yamanote said:
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.
 
  • #12,423
Jorge Stolfi said:
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?
 
  • #12,424
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.
 
  • #12,425
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.
 
  • #12,426
etudiant said:
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.
 
  • #12,427
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.
 
  • #12,428
SteveElbows said:
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.
 
  • #12,429
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
 
  • #12,430
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.
 
  • #12,431
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.
 
  • #12,432
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?
 
  • #12,433
zapperzero said:
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)
 
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  • #12,434
zapperzero said:
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)
 
  • #12,435
denislaurent said:
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.
 
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  • #12,436
zapperzero said:
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.
zapperzero said:
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.
zapperzero said:
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.
 
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  • #12,437
denislaurent said:
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.
 

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  • #12,438
Atomfritz said:
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
 
  • #12,439
Atomfritz said:
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.
 
  • #12,440
jmelson said:
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.
 
  • #12,441
zapperzero said:
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.
 
  • #12,442
Jim Lagerfeld said:
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
 
  • #12,443
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?
 
  • #12,444
Atomfritz said:
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.
 
  • #12,445
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?
 
  • #12,446
Rive said:
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.
 
  • #12,447
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).
 
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  • #12,448
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.
 
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  • #12,449
has unit 3 top floor been covered with something?
 
  • #12,450
tsutsuji said:
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])
 
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