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turi
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The release is planned for September (though it doesn't say whether it will be a public release):Sotan said:
Fukushima Japan Earthquake: nuclear plants Fukushima part 2
- Thread starter Greg Bernhardt
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- Earthquake Japan Nuclear Plants
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A magnitude-5.3 earthquake struck Fukushima, Japan, prompting concerns due to its proximity to the damaged nuclear power plant from the 2011 disaster. The U.S. Geological Survey reported the quake occurred at a depth of about 13 miles, but no tsunami warning was issued. Discussions in the forum highlighted ongoing issues with tank leaks at the plant, with TEPCO discovering loosened bolts and corrosion, complicating monitoring efforts. There are plans for fuel removal from Unit 4, but similar structures will be needed for Units 1 and 3 to ensure safe decontamination. The forum also addressed the need for improved groundwater management and the establishment of a specialist team to tackle contamination risks.
Engineering news on Phys.org
turi
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A new prompt report:
http://www.tepco.co.jp/en/press/corp-com/release/2015/1250926_6844.html
http://www.tepco.co.jp/en/press/corp-com/release/2015/1250926_6844.html
- Measured radioactivity spike on March 20, 2011 likely caused by changed wind direction.
- Failed venting of unit 2: Failure of rupture disk to rupture still a possible cause. Data inconclusive.
- PCV of unit 1 became hot at the top: Cooling devices for spraying the top are a countermeasure option.
turi
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There has been an update regarding the treatment of contaminated water:
http://www.tepco.co.jp/en/decommision/planaction/alps/index-e.html
http://www.tepco.co.jp/en/press/corp-com/release/2015/1251076_6844.html
Almost all water has been treated for Strontium, 2/3 of the water has also gone through ALPS. The remaining 3% of untreated water will take more time to treat as it has a high calcium and magnesium content and/or is at the ground of tanks to be disassembled (where the installed pumps can't remove it completely).
http://www.tepco.co.jp/en/decommision/planaction/alps/index-e.html
http://www.tepco.co.jp/en/press/corp-com/release/2015/1251076_6844.html
Almost all water has been treated for Strontium, 2/3 of the water has also gone through ALPS. The remaining 3% of untreated water will take more time to treat as it has a high calcium and magnesium content and/or is at the ground of tanks to be disassembled (where the installed pumps can't remove it completely).
turi
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An even newer press release now announces that the water with high salt concentration has been treated as well and that only the water at the bottom of emptied tanks remains to be treated for strontium:
http://www.tepco.co.jp/en/press/corp-com/release/2015/1251105_6844.html
Addendum: The second link in my post above is wrong (the text is correct), it should be:
http://www.tepco.co.jp/en/press/corp-com/release/2015/1251076_6844.html
http://www.tepco.co.jp/en/press/corp-com/release/2015/1251105_6844.html
Addendum: The second link in my post above is wrong (the text is correct), it should be:
http://www.tepco.co.jp/en/press/corp-com/release/2015/1251076_6844.html
Sotan
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Tepco report dated May 28 (in Japanese):
http://www.tepco.co.jp/nu/fukushima-np/handouts/2015/images/handouts_150528_01-j.pdf
They measured again the water level in PCV Unit 1. Water level was found to be about 1000 mm under the grating. It was 650 mm under the grating when measured previously, in October 2011. They speculate about this difference and what it can tell us about the water leaks. The water level is established dynamically as a balance between the water that is poured into cool the fuel and fuel debris, and the water leaked out of the PCV and S/C (two such leaks have been identified already, the "sand cushion drain line" and the "bellows of the vacuum break line" in the suppression chamber). They used to pour in 5 tons of cooling water each hour before November 2011 - but only 4.5 tons per hour after that, so the water level difference could be explained by that. They also make some calculations which suggest that the "holes" causing the leaks mentioned above could amount to 2.4 square centimeters and 0.47 square centimeters, respectively (these numbers sound incredibly small, but I suppose a lot of water can leak through there... Not to mention that there may be other holes too, not found yet.)
http://www.tepco.co.jp/nu/fukushima-np/handouts/2015/images/handouts_150528_01-j.pdf
They measured again the water level in PCV Unit 1. Water level was found to be about 1000 mm under the grating. It was 650 mm under the grating when measured previously, in October 2011. They speculate about this difference and what it can tell us about the water leaks. The water level is established dynamically as a balance between the water that is poured into cool the fuel and fuel debris, and the water leaked out of the PCV and S/C (two such leaks have been identified already, the "sand cushion drain line" and the "bellows of the vacuum break line" in the suppression chamber). They used to pour in 5 tons of cooling water each hour before November 2011 - but only 4.5 tons per hour after that, so the water level difference could be explained by that. They also make some calculations which suggest that the "holes" causing the leaks mentioned above could amount to 2.4 square centimeters and 0.47 square centimeters, respectively (these numbers sound incredibly small, but I suppose a lot of water can leak through there... Not to mention that there may be other holes too, not found yet.)
Sotan
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A new Mid-to-Long Term Roadmap report (dated May 28) consisting of a set of documents is posted on Tepco website. In Japanese only.
This one document refers to preparations and activities carried out in view of the future removal of fuel debris:
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/d150528_11-j.pdf
Starting with page number 5 there is a presentation of the planned investigation of the inside of the PCV of Reactor 2.
Basically the investigations has 4 stages (A1 to A4 – page 5).
A1 is the investigation of the state of the CRD rail and it has been done in August 2013.
A2 refers to the platform located inside the pedestal room – and this is the stage further detailed in the present document.
A3 (planned for 2016) refers to the same platform inside the pedestal room, with accent on the region located right under the CRDs.
A4 will focus on the situation of the bottom of the pedestal room.
(page 6) A2 investigation will aim, first of all, to check the situation of cables found in penetration X-6 and if/how they can be avoided, as well as the state of the first part of the CRD rail.
Then a guiding pipe (100 mm) will be inserted in the 115mm X-6 penetration, and through this pipe a crawler robot (with lights, cameras, temperature and radiation measuring devices) will get in.
(page 7) Items to be checked in this investigation (tentative)
Item 1 is the situation of cables inside X-6 penetration
Items 2-1 through 2-5 refer to checking the state of the CRD rail (in preparation for investigations A3 and A4) as well as identification of possible fallen objects located on the platform inside the pedestal
Items 3-1 and 3-2 are the ones that will make use of the crawler robot and refer to the state of the platform and of the lower part of the CRD rail. (Also include checking the position and state of the “CRD changing machine”).
(page 8) Tentative schedule of investigation A2. Training in May, on-site preparations till June 11, then the work will begin to remove the wall of concrete blocks placed in front of X-6 penetration – to end on July 9.
In parallel preparations and training with the devices used for investigation, and the actual opening of X-6 and start of investigation planned after the concrete blocks are removed.
(page 9) Explanation regarding the wall of concrete blocks placed in front of X-6 penetration. There are about 138 such concrete blocks that will have to be removed by remote-controlled devices. (There are abouit 10 mSv/h in the space in front of the concrete blocks wall.) Heaviest block is believed to weigh about 36 kg.
(page 10) Outline of the operation for removing the concrete blocks
It will be done using a machine (robot) controlled from the distance.
Removing one block will probably take about 15 minutes.
There will be a radiation dose measuring device on the manipulating arm of the robot, to sense any sharp changes in radiation, just in case. The radiation dose is expected to increase when removing these blocks (their main purpose seems to be shielding?), therefore a replacement shield (steel plate 100 mm thick) will be placed appropriately.
(page 11) Enumerates some risks related to this operation and envisioned ways to deal with them. Operation errors, blocks dropped, failures of the robot mechanisms, unexpected rise of radiation dose, stumbling on blocks heavier or larger than anticipated…
-------------------------------------
The document goes on then with another subject: muon imaging results.
Page 16~: a muon measurement image computed after 96 days of data gathering. Better image with less noise, smaller statistical errors and better clarity. The conclusion is the same though – no fuel left in the reactor core.
This one document refers to preparations and activities carried out in view of the future removal of fuel debris:
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/d150528_11-j.pdf
Starting with page number 5 there is a presentation of the planned investigation of the inside of the PCV of Reactor 2.
Basically the investigations has 4 stages (A1 to A4 – page 5).
A1 is the investigation of the state of the CRD rail and it has been done in August 2013.
A2 refers to the platform located inside the pedestal room – and this is the stage further detailed in the present document.
A3 (planned for 2016) refers to the same platform inside the pedestal room, with accent on the region located right under the CRDs.
A4 will focus on the situation of the bottom of the pedestal room.
(page 6) A2 investigation will aim, first of all, to check the situation of cables found in penetration X-6 and if/how they can be avoided, as well as the state of the first part of the CRD rail.
Then a guiding pipe (100 mm) will be inserted in the 115mm X-6 penetration, and through this pipe a crawler robot (with lights, cameras, temperature and radiation measuring devices) will get in.
(page 7) Items to be checked in this investigation (tentative)
Item 1 is the situation of cables inside X-6 penetration
Items 2-1 through 2-5 refer to checking the state of the CRD rail (in preparation for investigations A3 and A4) as well as identification of possible fallen objects located on the platform inside the pedestal
Items 3-1 and 3-2 are the ones that will make use of the crawler robot and refer to the state of the platform and of the lower part of the CRD rail. (Also include checking the position and state of the “CRD changing machine”).
(page 8) Tentative schedule of investigation A2. Training in May, on-site preparations till June 11, then the work will begin to remove the wall of concrete blocks placed in front of X-6 penetration – to end on July 9.
In parallel preparations and training with the devices used for investigation, and the actual opening of X-6 and start of investigation planned after the concrete blocks are removed.
(page 9) Explanation regarding the wall of concrete blocks placed in front of X-6 penetration. There are about 138 such concrete blocks that will have to be removed by remote-controlled devices. (There are abouit 10 mSv/h in the space in front of the concrete blocks wall.) Heaviest block is believed to weigh about 36 kg.
(page 10) Outline of the operation for removing the concrete blocks
It will be done using a machine (robot) controlled from the distance.
Removing one block will probably take about 15 minutes.
There will be a radiation dose measuring device on the manipulating arm of the robot, to sense any sharp changes in radiation, just in case. The radiation dose is expected to increase when removing these blocks (their main purpose seems to be shielding?), therefore a replacement shield (steel plate 100 mm thick) will be placed appropriately.
(page 11) Enumerates some risks related to this operation and envisioned ways to deal with them. Operation errors, blocks dropped, failures of the robot mechanisms, unexpected rise of radiation dose, stumbling on blocks heavier or larger than anticipated…
-------------------------------------
The document goes on then with another subject: muon imaging results.
Page 16~: a muon measurement image computed after 96 days of data gathering. Better image with less noise, smaller statistical errors and better clarity. The conclusion is the same though – no fuel left in the reactor core.
etudiant
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Sotan said:Tepco report dated May 28 (in Japanese):
http://www.tepco.co.jp/nu/fukushima-np/handouts/2015/images/handouts_150528_01-j.pdf
They measured again the water level in PCV Unit 1. Water level was found to be about 1000 mm under the grating. It was 650 mm under the grating when measured previously, in October 2011. They speculate about this difference and what it can tell us about the water leaks. The water level is established dynamically as a balance between the water that is poured into cool the fuel and fuel debris, and the water leaked out of the PCV and S/C (two such leaks have been identified already, the "sand cushion drain line" and the "bellows of the vacuum break line" in the suppression chamber). They used to pour in 5 tons of cooling water each hour before November 2011 - but only 4.5 tons per hour after that, so the water level difference could be explained by that. They also make some calculations which suggest that the "holes" causing the leaks mentioned above could amount to 2.4 square centimeters and 0.47 square centimeters, respectively (these numbers sound incredibly small, but I suppose a lot of water can leak through there... Not to mention that there may be other holes too, not found yet.)
Why the continuing water injection if the evidence is that the fuel is no longer in the reactor? Presumably that fuel now sits well below the current water level.
Seen that there is now enough water processing capacity, would it not be better to draw down the water level in the plant so that ground water flows in rather than having contaminated water flow out?
Sotan
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I always underlined I am no specialist, but regarding your question etudiant:
Perhaps they continue to pour in water exactly in order to keep the fuel submerged - wherever it is? I mean, it still needs cooling, doesn't it? Presumably, stopping the water injection would lead to further retraction of the water level, through the leaks, and thus expose the fuel.
If cooling is no longer needed then it's a different story...
Perhaps they continue to pour in water exactly in order to keep the fuel submerged - wherever it is? I mean, it still needs cooling, doesn't it? Presumably, stopping the water injection would lead to further retraction of the water level, through the leaks, and thus expose the fuel.
If cooling is no longer needed then it's a different story...
etudiant
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Sotan said:I always underlined I am no specialist, but regarding your question etudiant:
Perhaps they continue to pour in water exactly in order to keep the fuel submerged - wherever it is? I mean, it still needs cooling, doesn't it? Presumably, stopping the water injection would lead to further retraction of the water level, through the leaks, and thus expose the fuel.
If cooling is no longer needed then it's a different story...
Thank you for your added thoughts. I'm no specialist either, just trying to see the logic here and the TEPCO releases don't address the question.
There is essentially no fuel left in reactor 1, so what is getting cooled?
That blob of fuel material is now down way below the water surface, somewhere in the pedestal., so it is not reached by the injections.
Of course we do not have muon pictures of reactors 2 and 3, so maybe the situation there is different.
Perhaps the idea is that as things are currently reasonably stable, no change should be made.
Rive
Science Advisor
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The main fuel mass is down, but there is no guarantee that some debris is not left there above water level.etudiant said:Why the continuing water injection if the evidence is that the fuel is no longer in the reactor?
Also, with adding 'clean' water and removing contaminated water, the average contamination level in the basement water is decreasing (as I recall, a year ago it was ~ two decades lower than in the beginning).
Hiddencamper
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Rive said:The main fuel mass is down, but there is no guarantee that some debris is not left there above water level.
Also, with adding 'clean' water and removing contaminated water, the average contamination level in the basement water is decreasing (as I recall, a year ago it was ~ two decades lower than in the beginning).
With the reactor breached, adding water means any that spills out goes into the containment, where the fuel debris should be.
I mean, there's no reason you can't inject to the dry well spray spargers, but injecting to the reactor core guarantees you get any debris in there too.
If you stop injecting, between lowering level and heating up water you run the risk of airborne contamination. Not desirable. The water also acts as shielding.
etudiant
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Is the fuel still generating that much heat?
We're now 4 years since the accident, how much residual activity does the fuel have.
There was a curve, from MIT I think, that projected the decay heat. The levels by now should be much less than earlier if that chart was accurate.
I'm sort of thinking of the Chernobyl 'Elephants Foot' as a model, a mass of congealed fuel, containment steel and concrete material. Is that still unrealistic?
We're now 4 years since the accident, how much residual activity does the fuel have.
There was a curve, from MIT I think, that projected the decay heat. The levels by now should be much less than earlier if that chart was accurate.
I'm sort of thinking of the Chernobyl 'Elephants Foot' as a model, a mass of congealed fuel, containment steel and concrete material. Is that still unrealistic?
Hiddencamper
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I can't say for certain. Remember the elephant's foot mixed with a ton of sand from around the reactor, which my understanding is that it helped to change its structure and allow it to solidify.
The fuel still releases heat. It's "safe" if it's uncovered with water, but you lose the shielding effect and now have airborne potential. Keeping it submerged prevents those issues.
It's not enough heat to do damage but it can be problematic in other ways.
The fuel still releases heat. It's "safe" if it's uncovered with water, but you lose the shielding effect and now have airborne potential. Keeping it submerged prevents those issues.
It's not enough heat to do damage but it can be problematic in other ways.
Rive
Science Advisor
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It is not. Generally, it takes 3-5 years for fuel to be ready for dry storage after removed from the core. However, it's not just about the heat generation. It's now a melted mass, with much lower surface/mass ratio, so it still can be/go hot if the cooling is not adequate.etudiant said:Is the fuel still generating that much heat?
Also, the mentioned 'elephant foot' started to crumble after some years. So corium indeed hase some potential to go airborne with time.
nikkkom
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I think it's just inertia.
If you change anything and something bad happens, you are getting the blame.
If you change anything and something bad happens, you are getting the blame.
Sotan
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http://www.world-nuclear-news.org/W...ima-fuel-debris-removal-in-2021-04061501.html
Article based on statements of the executive director of the Nuclear Damage Compensation and Decommissioning Facilitation Corporation (NDF) made on June 3 at the VII Atomexpo conference in Moscow.
Article based on statements of the executive director of the Nuclear Damage Compensation and Decommissioning Facilitation Corporation (NDF) made on June 3 at the VII Atomexpo conference in Moscow.
Sotan
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http://www.tepco.co.jp/nu/fukushima-np/handouts/2015/images/handouts_150629_05-j.pdf
This is a report regarding the preparations being made for that A2 investigation of PCV of Unit 2. (There is a previous post about this operation on page 35 of this thread.)
It is in Japanese only but still worth taking a look.
Page 2 shows that they have removed most of the concrete blocks located in the front of the X-6 penetration, using a remote controlled robot.
Page 4 shows the results of radiation dose measurements around X6 penetration. Highest recorded value was 1197 mSv/h (informative value only, considering that the apparatus used for measurement has a maximum scale value of 999 mSv/h). They believe that only about 100 mSv/h is direct radiation coming from the inside of the PCV - the rest being due to various contamination of the area. They plan to clean and shield the area as best as they can before starting investigation work.
Page 5 shows a very interesting photo: something melted and leaked through the bolted flange/lid that covers the X-6 penetration pipe. Some of the matter is still hanging down from the lid, some of it has fallen on the floor. They speculate that the matter is composed of rubber-like material from the O-ring that seals that lid as well as from the cables located inside the pipe, as well as, maybe, other stuff.
This is a report regarding the preparations being made for that A2 investigation of PCV of Unit 2. (There is a previous post about this operation on page 35 of this thread.)
It is in Japanese only but still worth taking a look.
Page 2 shows that they have removed most of the concrete blocks located in the front of the X-6 penetration, using a remote controlled robot.
Page 4 shows the results of radiation dose measurements around X6 penetration. Highest recorded value was 1197 mSv/h (informative value only, considering that the apparatus used for measurement has a maximum scale value of 999 mSv/h). They believe that only about 100 mSv/h is direct radiation coming from the inside of the PCV - the rest being due to various contamination of the area. They plan to clean and shield the area as best as they can before starting investigation work.
Page 5 shows a very interesting photo: something melted and leaked through the bolted flange/lid that covers the X-6 penetration pipe. Some of the matter is still hanging down from the lid, some of it has fallen on the floor. They speculate that the matter is composed of rubber-like material from the O-ring that seals that lid as well as from the cables located inside the pipe, as well as, maybe, other stuff.
turi
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After unsuccessfully trying to stop the water flow in the unit 2 trench by freezing the water, using special concrete was now successful. Tepco is awaiting approval to use the same procedure with the trench of unit 3.
http://www.tepco.co.jp/en/press/corp-com/release/2015/1253974_6844.html
http://www.tepco.co.jp/en/press/corp-com/release/2015/1253974_6844.html
Sotan
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I'm very glad to hear that it worked.
Some people were skeptical but it worked.
One worry less.
Some people were skeptical but it worked.
One worry less.
Sotan
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http://www.tepco.co.jp/nu/fukushima-np/handouts/2015/images/handouts_150701_05-j.pdf
(in Japanese)
Tepco report regarding the removal of spent fuel from the SFP of Unit 3
Page 2 – concept of the cover to be installed over the Reactor 3 building in order to remove the spent fuel from the SFP
Page 3 – overall view of the planned setting of the installations for spent fuel removal
Page 4 – tentative schedule. Red line is today. The cover should be in place at the end of 2017 and then the removal of the 566 bundles of fuel from the SFP should begin.
Page 5 – images showing the process of cover construction
Page 6 – radiation dose rates on the operating floor of Unit 3 (in fact, at floor + 5m height) at present are around 220 mSv/h in the area of the shield plug
Page 7 – radiation doses at operating floor + 50cm height.
Page 8 – expected radiation doses when the decontamination of the area is over – at operating floor + 50cm height.
Page 9 – explanations on the measures for decontamination and reduction of the radiation dose prior to actually starting the assembling work for the building cover and in the early stages of the assembly operations. Setting shielded “waiting areas” for workers to be protected from radiation when not actually involved in work.
Page 10 – images with the building cover during trial assembly.
Page 11 – they explain how they arrived at those expected values of radiation “after the decontamination is over”
Page 12 – measures for protection of the workers from radiation during the installation of the bridge for the transportation of the fuel bundles. The actual installation is to be done in one day, using 4 teams of 15 workers each, each team working for 1 hour and making use of various methods for shielding the workers, as seen in Page 13 too. Steel plates of 150mm thickness will reduce the radiation dose to 1/100 of whatever is around. Thinner plates (50mm thick) offering shielding to 1/3 of the ambient radiation dose will be used in cages and covers that can be moved and placed around by crane.
Page 14 contents some final remarks on further decontamination to be done, followed by radiation measurements and evaluation and then by the finalizing of the work plan and schedule for cover installation.
Pages 15~ are additional materials used in the preparation of the report.
Page 27: photo of the operating floor taken on Dec 8, 2014.
(in Japanese)
Tepco report regarding the removal of spent fuel from the SFP of Unit 3
Page 2 – concept of the cover to be installed over the Reactor 3 building in order to remove the spent fuel from the SFP
Page 3 – overall view of the planned setting of the installations for spent fuel removal
Page 4 – tentative schedule. Red line is today. The cover should be in place at the end of 2017 and then the removal of the 566 bundles of fuel from the SFP should begin.
Page 5 – images showing the process of cover construction
Page 6 – radiation dose rates on the operating floor of Unit 3 (in fact, at floor + 5m height) at present are around 220 mSv/h in the area of the shield plug
Page 7 – radiation doses at operating floor + 50cm height.
Page 8 – expected radiation doses when the decontamination of the area is over – at operating floor + 50cm height.
Page 9 – explanations on the measures for decontamination and reduction of the radiation dose prior to actually starting the assembling work for the building cover and in the early stages of the assembly operations. Setting shielded “waiting areas” for workers to be protected from radiation when not actually involved in work.
Page 10 – images with the building cover during trial assembly.
Page 11 – they explain how they arrived at those expected values of radiation “after the decontamination is over”
Page 12 – measures for protection of the workers from radiation during the installation of the bridge for the transportation of the fuel bundles. The actual installation is to be done in one day, using 4 teams of 15 workers each, each team working for 1 hour and making use of various methods for shielding the workers, as seen in Page 13 too. Steel plates of 150mm thickness will reduce the radiation dose to 1/100 of whatever is around. Thinner plates (50mm thick) offering shielding to 1/3 of the ambient radiation dose will be used in cages and covers that can be moved and placed around by crane.
Page 14 contents some final remarks on further decontamination to be done, followed by radiation measurements and evaluation and then by the finalizing of the work plan and schedule for cover installation.
Pages 15~ are additional materials used in the preparation of the report.
Page 27: photo of the operating floor taken on Dec 8, 2014.
etudiant
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Sotan said:http://www.tepco.co.jp/nu/fukushima-np/handouts/2015/images/handouts_150701_05-j.pdf
(in Japanese)
Tepco report regarding the removal of spent fuel from the SFP of Unit 3
Seems that a very large amount of serious preparation is under way. Japan is working the problem diligently.
Still, the image of the cleared top of reactor 3 was sobering, especially when combined with the radiation map.
This has a long ways to go.
Sotan
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I found this link on another related site:
http://www.jaif.or.jp/en/toshiba-and-irid-develop-small-robot-to-investigate-fukushima-daiichi-2-pcv-interior/
There is a video with the new robot working on a mock-up, quite interesting.
http://www.jaif.or.jp/en/toshiba-and-irid-develop-small-robot-to-investigate-fukushima-daiichi-2-pcv-interior/
There is a video with the new robot working on a mock-up, quite interesting.
nikkkom
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etudiant said:Seems that a very large amount of serious preparation is under way. Japan is working the problem diligently.
Yes, looks promising. Top of SFP is almost completely free of debris.
Still, the image of the cleared top of reactor 3 was sobering, especially when combined with the radiation map.
This has a long ways to go.
220 mSv/h is not high.
Remember the base of vent stack which has ~10000mSv/h...
etudiant
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nikkkom said:Yes, looks promising. Top of SFP is almost completely free of debris.
220 mSv/h is not high.
Remember the base of vent stack which has ~10000mSv/h...
There are much hotter spots indeed, but 220 mSv/hr is 4x the annual permitted dose for US radiation workers, so still too hot to allow longer term use of work teams.
jim hardy
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nikkkom said:220 mSv/h is not high.
comparatively it's not, as noted. ~ 22 R /hr? Our stay time would be under ten minutes , you'd get three months' worth of exposure in that time.
Hiddencamper
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jim hardy said:comparatively it's not, as noted. ~ 22 R /hr? Our stay time would be under ten minutes , you'd get three months' worth of exposure in that time.
Yeah, that's a stupid high dose. Keep deconning.
turi
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Unit 1 cover is being dismantled:
http://mainichi.jp/english/english/newsselect/news/20150728p2g00m0dm069000c.html
Fisheries agree for purified subdrain water to be released to the sea:
http://mainichi.jp/english/english/newsselect/news/20150728p2a00m0na016000c.html
http://mainichi.jp/english/english/newsselect/news/20150728p2g00m0dm069000c.html
Fisheries agree for purified subdrain water to be released to the sea:
http://mainichi.jp/english/english/newsselect/news/20150728p2a00m0na016000c.html
Last edited by a moderator:
Hiddencamper
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Has TEPCO sent the scorpion robot down the CRD cattle chute yet? I was really looking forward to that footage.
LabratSR
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Fukushima Operator Prepares to Lift 20-Ton Debris From Fuel Pool
http://blogs.wsj.com/japanrealtime/...repares-to-lift-20-ton-debris-from-fuel-pool/
http://blogs.wsj.com/japanrealtime/...repares-to-lift-20-ton-debris-from-fuel-pool/
Sotan
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http://www3.nhk.or.jp/news/genpatsu-fukushima/20150731/0440_robot.html
(Article in Japanese on the NHK site)
The investigation of the interior of the PCV of Reactor 2 at Fukushima Daiichi plant, which was tentatively scheduled for sometime next month, might be postponed towards December or even later in the worst case scenario, due to difficulties in planning the operation.
Tepco says the radiation level in the area of the PCV penetration pipe that is to serve for robot access - where they have been removing those concrete blocks - is high and using remote-controlled machines they haven't yet been able to remove all the blocks which appear stuck. They are trying to loosen them using chemical substances but at the same time they are considering whether it will be required to design stronger remote-controlled equipment. If it turns out that this is absolutely required, the investigation may be pushed towards December or even later. Even if they succeed to remove the stuck concrete blocks, the decontamination will still take some time, so August seems to be no longer a possibility for sending the robot in.
------------
http://www3.nhk.or.jp/news/genpatsu-fukushima/20150730/2123_trench.html
(Article in Japanese on the NHK site)
Tepco announces that on July 30th all the highly contaminated water from the trenches at Fukushima Daiichi has been removed and they are now filling the last portions of the pits and trenches with concrete (to be done in ~10 days or so). Thus one of the highest risks of contamination of the ocean has finally been averted.
-------------
http://www3.nhk.or.jp/news/genpatsu-fukushima/20150730/0402_gareki.html
(Article in Japanese on the NHK site)
The lifting of the collapsed FHM wreckage from the SFP of Unit 3 (mentioned by LabratSR above) is scheduled for August 2.
(Article in Japanese on the NHK site)
The investigation of the interior of the PCV of Reactor 2 at Fukushima Daiichi plant, which was tentatively scheduled for sometime next month, might be postponed towards December or even later in the worst case scenario, due to difficulties in planning the operation.
Tepco says the radiation level in the area of the PCV penetration pipe that is to serve for robot access - where they have been removing those concrete blocks - is high and using remote-controlled machines they haven't yet been able to remove all the blocks which appear stuck. They are trying to loosen them using chemical substances but at the same time they are considering whether it will be required to design stronger remote-controlled equipment. If it turns out that this is absolutely required, the investigation may be pushed towards December or even later. Even if they succeed to remove the stuck concrete blocks, the decontamination will still take some time, so August seems to be no longer a possibility for sending the robot in.
------------
http://www3.nhk.or.jp/news/genpatsu-fukushima/20150730/2123_trench.html
(Article in Japanese on the NHK site)
Tepco announces that on July 30th all the highly contaminated water from the trenches at Fukushima Daiichi has been removed and they are now filling the last portions of the pits and trenches with concrete (to be done in ~10 days or so). Thus one of the highest risks of contamination of the ocean has finally been averted.
-------------
http://www3.nhk.or.jp/news/genpatsu-fukushima/20150730/0402_gareki.html
(Article in Japanese on the NHK site)
The lifting of the collapsed FHM wreckage from the SFP of Unit 3 (mentioned by LabratSR above) is scheduled for August 2.
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