Japan Earthquake: nuclear plants Fukushima part 2

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131007/index.html At 9:47 AM on 7 October, unit 1 reactor water injection temporarily stopped, but it was restarted soon afterwards using a backup system. Other equipments such as unit 1 and unit 2 PCV gas purification systems also stopped and were similarily restarted using backup systems. The cause is an employee pushing a stop button during an electric power panel inspection.

http://www.tepco.co.jp/nu/fukushima-np/handouts/2013/images/handouts_131007_08-j.pdf Japanese language handout about the equipment shutdowns. The timeline says reactor injection pump B was automatically switched to pump A at 10:10 AM.

Fukushima Daiichi accident analysis study group 4th meeting, 7 October 2013 : http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/20131007.html

http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0004_99.pdf Agenda
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0004_01.pdf Unit 4 hydrogen explosion
http://www.tepco.co.jp/nu/fukushima-np/handouts/2013/images/handouts_131007_03-j.pdf Timing of the tsunami arrival into the plant premises (Japanese, 35 pages)
http://www.tepco.co.jp/nu/fukushima-np/handouts/2013/images/handouts_131007_04-j.pdf Enlarged photographs of the arrival of the tsunami (19 pages)
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0004_04.pdf Possibility of unit 3 recriticality
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0004_05.pdf Possibility of unit 1 small scale LOCA after tsunami arrival​

--> 1st meeting : https://www.physicsforums.com/showpost.php?p=4400944&postcount=14004

 

[zapperzero]

http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0004_04.pdf Possibility of unit 3 recriticality

Well well. Discussion of the (im)possibility of recriticality in Unit 3 SFP. I wonder if anyone will bother to do an analysis of the possibility of recriticality in reflooded debris bed of same.

 

[tsutsuji]

Fukushima Daiichi accident analysis study group 2nd meeting, 17 June 2013 : http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/20130617.html

http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_99.pdf Agenda
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_01.pdf Status, etc. at the time of unit 1 reactor building 4th floor water outflow (hearing documents)
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_02.pdf Results of onsite inspection concerning unit 1 reactor building 4th floor water outflow
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_03.pdf Unit 1 spent fuel pool sloshing assessment
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_04.pdf Conclusions about unit 1 reactor building 4th floor water outflow
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_05.pdf Unit 4 spent fuel pool hydrogen generation
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_06.pdf Unit 4 reactor building hydrogen explosion preliminary inspection results and onsite inspection plans (draft)
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_07.pdf Creation of documentation pertaining to plant behaviour during the Fukushima Daiichi accident

attachment :
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0002_08.pdf Unit 1 reactor building 4th floor water outflow (document from the 1st meeting)​

 

[tsutsuji]

Fukushima Daiichi accident analysis study group 3rd meeting, 30 August 2013 : http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/20130830.html

http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0003_99.pdf Agenda
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0003_01.pdf Report on the studies about unit 1 reactor building 4th floor water outflow
(video) http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0003_01_m.wmv Simulation result of pool water sloshing during earthquake
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0003_02.pdf Studies about unit 1 reactor building 4th floor water outflow
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0003_03.pdf Results of onsite inspection concerning unit 4 reactor building hydrogen explosion
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0003_04.pdf Unit 1 loss of emergency AC power line A
http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0003_05.pdf Unit 3 spent fuel pool criticality possibility and white smoke generation​

 

[zapperzero]

http://www.nsr.go.jp/committee/yuushikisya/jiko_bunseki/data/0003_05.pdf
Those pics look awfully similar to what people on here were doing... a year ago.
The one on page 5 says 128 degrees Celsius... that would be superheated steam? They seem to say that IF the SFP didn't make the steam via criticality, it must have come through one of the transfer gate seals or something like that...

 

[tsutsuji]

Fukushima Daiichi decommissioning countermeasure promoting conference, 8th secretariat meeting, 26 September 2013 : http://www.meti.go.jp/earthquake/nuclear/20130926_01.html

[Previous instalments :

3 December 2012 : https://www.physicsforums.com/showpost.php?p=4194857&postcount=13817

25 December 2012 : https://www.physicsforums.com/showpost.php?p=4321002&postcount=13887

31 January 2013 : https://www.physicsforums.com/showpost.php?p=4320949&postcount=13886

7 March 2013 : https://www.physicsforums.com/showpost.php?p=4319851&postcount=13883

2nd secretariat meeting, 26 April 2013 : https://www.physicsforums.com/showpost.php?p=4385768&postcount=13985 ]
​

Mid and long term roadmap progress presentation by Tepco:

http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01a.pdf Agenda
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01b.pdf Participants

1-1 Plant status
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01c.pdf Plant parameters
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01d.pdf Accumulated water storage and treatment status
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01e.pdf Table of tanks in each area

2
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01f.pdf Mid and long term roadmap progress status (abstract)

3
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01g.pdf Decommissioning and contaminated water countermeasure ministerial level (1st) meeting

4
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01h.pdf Contaminated water countermeasure onsite adjustment (1st) meeting

5 Study and execution in each field

5-1 Cooling by closed loop water injection
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01j.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01k.pdf Units 1,2,3 PCV gas condensate water sampling results (all alpha, tritium)

5-2 Treatment of accumulated water
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01m.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01n.pdf H4 area tank leakage site survey status
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01p.pdf Survey of contamination consequences due to tank leakage
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01q.pdf Status of accumulated water inside tank area dikes
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01r.pdf Multinuclide removal facility batch treatment tank leakage causes and countermeasures
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01s.pdf Start of work for subdrain purification equipment, etc.
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01s.pdf Ground water bypass progress status (temporary tank water quality survey results)

5-3 Countermeasures to reduce environmental radiations
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01u.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01v.pdf Inside premises decontamination progress status
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01w.pdf groundwater east of turbine buildings and seawater radioactive substance concentration status

5-4 Improvement of working conditions
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01x.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01y.pdf Fukushima Daichi and Daini nuclear plants influenza infection prevention and contagion stoppage measures
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01z.pdf Setting of full mask wearing exemption areas in units 5 and 6

5-5 Countermeasures for spent fuels pools
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01aa.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01bb.pdf Layout map of working areas of units 1, 3 and 4 top part debris removal work and covering work for the purpose of fuel removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01cc.pdf Spent fuel conservation status
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01dd.pdf Unit 3 top part debris removal work
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01ee.pdf Work progress status toward unit 4 fuel removal [the red circles on the last two pages indicate the debris whose removal has been completed]
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01ff.pdf Unit 3 remote controlled giant crane extremity jib mast bending and falling
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01gg.pdf Gas exhaust system shutdown for the purpose of unit 1 reactor building cover dismantling
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01hh.pdf Application for approval of Special Atomic Facility management plan modification

5-6 Preparations for fuel debris removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01jj.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01kk.pdf Suppression chamber inner water level measurement robot generic technology development qualification test (prompt report)
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01mm.pdf Suppression chamber inner water level measurement robot generic technology development qualification test

5-7 Treatment and disposal of radioactive waste
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01nn.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01pp.pdf Debris, cut down trees management status
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01qq.pdf Cut down tree container temperature trends
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01rr.pdf Earthquake safety assessment against units 1 and 2 exhaust gas stack component part damage (interim report)

 

[tsutsuji]

Fukushima Daiichi decommissioning countermeasure promoting conference, 7th secretariat meeting, 28 August 2013 : http://www.meti.go.jp/earthquake/nuclear/20130828_01.html

[Previous instalments :

3 December 2012 : https://www.physicsforums.com/showpost.php?p=4194857&postcount=13817

25 December 2012 : https://www.physicsforums.com/showpost.php?p=4321002&postcount=13887

31 January 2013 : https://www.physicsforums.com/showpost.php?p=4320949&postcount=13886

7 March 2013 : https://www.physicsforums.com/showpost.php?p=4319851&postcount=13883

2nd secretariat meeting, 26 April 2013 : https://www.physicsforums.com/showpost.php?p=4385768&postcount=13985

8th secretariat meeting, 26 September 2013: https://www.physicsforums.com/showpost.php?p=4530539&postcount=41 ]
​

Mid and long term roadmap progress presentation by Tepco:

http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01a.pdf Agenda
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01b.pdf Participants

1-1 Plant status
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01c.pdf Plant parameters
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01d.pdf Accumulated water storage and treatment status
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01e.pdf Unit 3 reactor building steam-like thing generation

2
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01f.pdf Mid and long term roadmap progress status (abstract)

3 Study and execution in each field

3-1 Cooling by closed loop water injection
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01g.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01h.pdf Unit 2 PCV permanent monitoring tool installation and accumulated water sampling

3-2 Treatment of accumulated water
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01j.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01k.pdf Status of response to multinucide removal facility batch treatment tank corrosion phenomenon
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01m.pdf H4 tank area contaminated water leakage
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01n.pdf Countermeasures between unit 1 and unit 2 water intake channels
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01p.pdf Into-buildings ground water seepage points survey status
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01q.pdf Ground water bypass progress status

3-3 Countermeasures to reduce environmental radiations
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01r.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01s.pdf Groundwater east of turbine buildings and seawater radioactive substance concentration status
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01t.pdf Assessment results of additional releases from reactor buildings (as of August 2013)

3-4 Improvement of working conditions
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01u.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01v.pdf Status of survey concerning seismic-isolated main building dust concentration rise and occurrence of body contaminated people

3-5 Countermeasures for spent fuels pools
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01w.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01x.pdf Layout map of working areas of units 1, 3 and 4 top part debris removal work and covering work for the purpose of fuel removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01y.pdf Unit 3 top part debris removal work
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01z.pdf Work progress status toward unit 4 fuel removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01aa.pdf Spent fuel conservation status
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01bb.pdf Preliminary survey toward unit 1 5th floor survey
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01cc.pdf Unit 4 reactor well and PCV, spent fuel pool internal survey results
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01dd.pdf Start of the works to perform debris removal inside unit 4 reactor well and PCV, spent fuel pool, and transfer of inside-reactor equipments
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01ee.pdf Results of (the 6th) periodic inspection to check unit 4 reactor building soundness

3-6 Preparations for fuel debris removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01ff.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01gg.pdf Analysis results of units 1 and 2 torus room accumulated water and deposits
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01hh.pdf Unit 2 PCV internal survey results

3-7 Treatment and disposal of radioactive waste
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01jj.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01kk.pdf Debris, cut down trees management status
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01mm.pdf Cut down tree container temperature trends
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01nn.pdf Reactor building core boring samples analysis results

4
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01pp.pdf Setting of "Contaminated water - tank countermeasure headquarters"

5
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01qq.pdf Outline of "International Research institute for Nuclear Decommissioning" and plans for its practical use

 

[LabratSR]

The Level of Competence at TEPCO

I'm speechless

http://ex-skf.blogspot.com/2013/10/pictorial-elementary-mistake-in-water.html

 

[tsutsuji]

I'm speechless

http://ex-skf.blogspot.com/2013/10/pictorial-elementary-mistake-in-water.html

See also :

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_131003_01-e.pdf English handout about the B-A-5 tank roof plate leakage

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131009/0630_husyoku.html Concerning the 300 ton tank [H4 area tank No. 5] leakage, Tepco found that in two locations a 3 mm wide, 1 or 2 cm long gap had been generated by corrosion between bolt holes at the bottom of the tank. As soon as possible Tepco will discontinue using bolt-mounted tanks, and switch to welded tanks.

http://www.tepco.co.jp/nu/fukushima-np/handouts/2013/images/handouts_131008_03-j.pdf H4 area tank No. 5 bottom plate inspection

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131009/1313_haikan.html On 9 October, by mistake, workers removed a pipe in a reverse osmosis equipment and highly contaminated water leaked. The workers were soaked by contaminated water. The extent of their contamination is being checked. The water has 37,000,000 Bq/l of beta. The leak was stopped 50 minutes later. Water did not overflow the dike, so that there is no consequence on the environment.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131009/index.html The quantity is 1 cm depth in the 12 m X 60 m dike or about 7 tons. 6 among the 11 workers were contaminated on their skin.

http://www.tepco.co.jp/nu/fukushima-np/handouts/2013/images/handouts_131009_04-j.pdf Leakage inside reverse osmosis RO-3 tent

 

[jlduh]

Don't know if this was already posted here, but i didn't find it so i post a link to pictures and report about the broken joints on the stack structures of N°1 and 2 reactors. Some are of very good resolution.

http://photo.tepco.co.jp/date/2013/201310-j/131007-01j.html

http://www.tepco.co.jp/nu/fukushima-np/handouts/2013/images/handouts_131007_06-j.pdf

The way the cracks appear seems to indicate some fatigue cracks under stress in my opinion, you can see that they follow the edge of the steel plate that is in between (the joints are bolted), and on some pictures, you can see some "baby" cracks initiating from the centre of the plate, where the welded reinforcement ends.

The clear risk (increased by the fact this area measured more than 10 Sv/h, i say more because it seems 10 was the max reading possible with the equipement used) is that the stability of the stack could be lowered, increasing fatigue and stresses on the remaining joints resulting in an accelerated deterioration process in the near months/years (earthquakes, strong winds/typhoons, etc.).

 

[tsutsuji]

fukushima daiichi decommissioning countermeasure promoting conference, 7th secretariat meeting, 28 august 2013 :

3-6 preparations for fuel debris removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130828/130828_01hh.pdf unit 2 pcv internal survey results

01/10

02/10

03/10

04/10

05/10

06/10

 

[tsutsuji]

07/10

08/10

09/10

10/10

 

[tsutsuji]

fukushima daiichi decommissioning countermeasure promoting conference, 8th secretariat meeting, 26 september 2013

5-6 preparations for fuel debris removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01mm.pdf suppression chamber inner water level measurement robot generic technology development qualification test

01/11

02/11

03/11

04/11

05/11

06/11

 

[tsutsuji]

07/11

08/11

09/11

10/11

11/11

 

[tsutsuji]

fukushima daiichi decommissioning countermeasure promoting conference, 8th secretariat meeting, 26 september 2013

5-6 preparations for fuel debris removal

http://www.meti.go.jp/earthquake/nuclear/pdf/130926/130926_01kk.pdf suppression chamber inner water level measurement robot generic technology development qualification test (prompt report)

1/4

2/4

3/4

4/4

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131013/1145_kashou.html The United Nations' scientific comittee on the effects of atomic radiation (UNSCEAR) says Tepco could have underestimated the workers' exposure caused by the accident by 20% as a result of not taking account short lived elements such as Iodine 133.

http://www.un.org/Docs/journal/asp/ws.asp?m=A/68/46 UNSCEAR report (General Assembly Official Records Sixty-eighth session Supplement No. 46)

 

[tsutsuji]

Fukushima Daiichi decommissioning countermeasure promoting conference, 6th secretariat meeting, 25 July 2013 : http://www.meti.go.jp/earthquake/nuclear/20130725_01.html

[Other instalments :

3 December 2012 : https://www.physicsforums.com/showpost.php?p=4194857&postcount=13817

25 December 2012 : https://www.physicsforums.com/showpost.php?p=4321002&postcount=13887

31 January 2013 : https://www.physicsforums.com/showpost.php?p=4320949&postcount=13886

7 March 2013 : https://www.physicsforums.com/showpost.php?p=4319851&postcount=13883

2nd secretariat meeting, 26 April 2013 : https://www.physicsforums.com/showpost.php?p=4385768&postcount=13985 ]

7th secretariat meeting, 28 August 2013 : https://www.physicsforums.com/showpost.php?p=4530916&postcount=42

8th secretariat meeting, 26 September 2013: https://www.physicsforums.com/showpost.php?p=4530539&postcount=41
​

Mid and long term roadmap progress presentation by Tepco:

http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01a.pdf Agenda
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01b.pdf Participants

1-1 Plant status
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01c.pdf Plant parameters
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01d.pdf Accumulated water storage and treatment status
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01e.pdf Unit 3 reactor building steam-like thing generation

2
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01f.pdf Mid and long term roadmap progress status (abstract)

3 Study and execution in each field

3-1 Cooling by closed loop water injection
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01g.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01h.pdf Unit 2 TIP guide tube soundness check results and future response
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01j.pdf Unit 1 nitrogen injection modification test results
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01k.pdf Unit 2 S/C nitrogen injection test for the purpose of hydrogen purge (second time) (abstract)

3-2 Treatment of accumulated water
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01m.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01n.pdf Future response to multinucide removal facility batch treatment tank leakage
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01p.pdf Ground water bypass progress status
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01q.pdf Underground water storage tank response status

3-3 Countermeasures to reduce environmental radiations
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01r.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01t.pdf Measurement results of groundwater east of turbine buildings
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01u.pdf Specialist study group on the reduction of radioactive substance concentrations in the port seawater
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01v.pdf Unit 2 water intake electric power cable trench sampling investigation results
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01w.pdf Assessment results of additional releases from reactor buildings (as of July 2013)
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01x.pdf Present status and countermeasures against seaside ground water and seawater radioactive substance concentration rise problem

3-4 Improvement of working conditions
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01y.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01z.pdf Revision of the domain of duties of female employees working in the nuclear activities at Fukushima Daiichi Nuclear Plant

3-5 Countermeasures for spent fuels pools
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01aa.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01bb.pdf Layout map of working areas of units 1, 3 and 4 top part debris removal work and covering work for the purpose of fuel removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01cc.pdf Unit 3 top part debris removal work
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01dd.pdf Unit 4 reactor building covering work
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01ee.pdf Spent fuel storage status (as of 20 July 2013)
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01ff.pdf End of exterior panels installation on the outer walls and roof of unit 4 cover for the purpose of fuel removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01gg.pdf End of grounding work for unit 4 fuel handling machine

3-6 Preparations for fuel debris removal
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01hh.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01jj.pdf Removal of obstacles cuh as the debris on the 1st floors of unit 1 and unit 3 reactor buildings
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01kk.pdf Results of inspection around the PCV penetrations on high locations in unit 2 reactor building first foor
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01mm.pdf Execution of unit 2 PCV internal reinvestigation

3-7 Treatment and disposal of radioactive waste
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01nn.pdf Schedule
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01pp.pdf Debris, cut down trees management status
http://www.meti.go.jp/earthquake/nuclear/pdf/130725/130725_01qq.pdf Cut down tree container temperature trends

 

[tsutsuji]

www.tepco.co.jp/cc/press/betu13_j/images/130830j0101.pdf Facilities for fuel removal from the spent fuel pool (447 pages, Japanese, released on 30 August 2013)

It contains new information about the fresh fuel removed from unit 4, and the removal facilities being installed in unit 4.

 

[etudiant]

Thank you again, Tsutsuji-san, for your sustained work keeping us posted on the progress of the cleanup effort.
Without your help, there would not be any reasonably non partisan information available to English language speakers about this work.
Meanwhile, it seems the 'nuclear village' is gradually starting to come to grips with the problem and developing new solutions to overcome the many difficulties involved.
I was struck by the intensity of the radiation inside Reactor 2, estimated to be 24-36 Sv/hr along the CRD replacement rail, rising as the probe approached the pedestal. That high a level more than 2 years after the accident means the site will be inaccessible to people for many years yet.
Working in that framework will require entirely new techniques. Hopefully the Japanese government will be able to rally the nation to make this cleanup a cause for all Japan, because it will take a national effort to achieve.

 

[a.ua.]

etudiant

estimated to be 24-36 Sv/hr along the CRD replacement rail, rising as the probe approached the pedestal. That high a level more than 2 years after the accident means the site will be inaccessible to people for many years yet.

However there is nothing stopping just open the door to the containment and send the robot.

The Soviet Union used a toy, a toy tank, (the price 10 $ ).
2 years after ...
Then they saw "shining" to 100 Sv

however is meaningless walk there now.
you just need to stop the leak.

 

[etudiant]

etudiant


However there is nothing stopping just open the door to the containment and send the robot.

The Soviet Union used a toy, a toy tank, (the price 10 $ ).
2 years after ...
Then they saw "shining" to 100 Sv

No argument that ingenuity is also found outside of Japan.
Still, I'm impressed that they seem to have developed a device that will reliably measure water levels inside the torus from the outside, despite the radiation and contaminated water in the measurement space.
As for the leaks, they now seem to be a chronic rather than a critical issue.
Afaik, the contamination level of the leaking water is about 1% of what it was in the early days of the crisis, so even if it takes 20 years to plug the leaks, the additional pollution is maybe 20% of what has already been released.
If TEPCO can empty the reactor 4 spent fuel pool as planned, starting next month, it would be a clear signal to the world that the cleanup is making real progress.

 

[jadair1]

Thank you again, Tsutsuji-san, for your sustained work keeping us posted on the progress of the cleanup effort.
Without your help, there would not be any reasonably non partisan information available to English language speakers about this work.
Meanwhile, it seems the 'nuclear village' is gradually starting to come to grips with the problem and developing new solutions to overcome the many difficulties involved.
I was struck by the intensity of the radiation inside Reactor 2, estimated to be 24-36 Sv/hr along the CRD replacement rail, rising as the probe approached the pedestal. That high a level more than 2 years after the accident means the site will be inaccessible to people for many years yet.
Working in that framework will require entirely new techniques. Hopefully the Japanese government will be able to rally the nation to make this cleanup a cause for all Japan, because it will take a national effort to achieve.

Just how dangerous is 24-36 Sv/hr, I'm a math and electronics guy and do not know much about radiations possible effect on people.

Could properly protected people work in a field like that?

 

[elektrownik]

Just how dangerous is 24-36 Sv/hr, I'm a math and electronics guy and do not know much about radiations possible effect on people.

Could properly protected people work in a field like that?

lethal dose is 7-8 Sv/h, people can work when there is 0,5 Sv/h max during nuclear accident and 1 Sv/h when the are saving other people's live

 

[Rive]

Just how dangerous is 24-36 Sv/hr, I'm a math and electronics guy and do not know much about radiations possible effect on people.

Could properly protected people work in a field like that?

Mind the "/h" part.
Allowed dose (for a year) for workers protecting life in emergency is 250mSv, protecting valuables in emergency is 100mSv, otherwise 50mSv (US standards, as far as I know).

First direct symptoms due radiation (absorbed in a short period) expected around 400mSv.

So in field 25 Sv/h a worker is permitted to work for ~ 0.05/25= 0.002h which is ~ 7.2 seconds if I did the math correctly.
Fatal dose is around 4Sv (in this case this limit would be 'earned' within 10-15minutes).The time limit can be extended with some special clothing (check some Chernobyl vids).

 

[turi]

The time limit could be extended with some special clothing (check some Chernobyl vids).

For lead the half-value thickness for 2 MeV gamma radiation is 1.4 cm. That's one heavy suit... And it makes you probably working half as fast than working without it, eliminating its usefulness.

 

[a.ua.]

more practical to use a protective shield of lead.
Given that the source of dot.
Similar protection (much lightly built) were seen in the photo of Fukushima Unit 4.
on the north side.

 

[LabratSR]

Strongest typhoon in 10 years heading for Fukushima

http://www.japantoday.com/category/national/view/fukushima-in-path-of-strong-typhoon

 

[LabratSR]

TEPCO Releasing Low Level Contaminated Water

http://ex-skf.blogspot.com/2013/10/large-and-strong-typhoon-no26.html

 

[a.ua.]

Request for Information (RFI) for Contaminated Water Issues

 

[Hiddencamper]

etudiant


However there is nothing stopping just open the door to the containment and send the robot.

The Soviet Union used a toy, a toy tank, (the price 10 $ ).
2 years after ...
Then they saw "shining" to 100 Sv

however is meaningless walk there now.
you just need to stop the leak.

The issue is getting into containment requires using large gantry cranes to lift the massive shield plugs in front of the containment hatches, then breaching 2 airlocks, which, when breached, will contaminate the **** out of the reactor building and provide a pathway for a lot of shine. What also makes it challenging is the subpile room is not at the same elevation as the entry hatches, and requires some vertical maneuvering which would be challenging for a robot. I'm not positive if Mark Is have a separate hatch going into the subpile room undervessel, but I have seen hatches like that before.

At Chernobyl, they had no containment, so it was a matter of drilling through spots then running the toy tank in. But I'm sure you saw the video, those guys were less than stellar about limiting their exposure and would do what they could to hide it. Now a days, with digital dosimeters, you can't even do that unless you are doing something to blatently shield your dosimeter.

Without an understanding of the physical layout of the BWR containment system its hard to understand why you can't just send a robot on. As someone who was in a BWR drywell chamber within the last week, you pretty much need scaffold to get anywhere important. The only areas you can easily access are the reactor recirculation pumps, and usually there is a permanent ladder up to the SRV/MSIV mezz

 

[LabratSR]

Fuel removal from undamaged Fukushima reactor


"The removal of fuel from the undamaged reactor of unit 6 of the Fukushima Daiichi plant began today after workers completed operations to remove the reactor pressure vessel lid and major components."

http://www.world-nuclear-news.org/RS-Fuel_removal_from_undamaged_Fukushima_reactor-1710134.html

 

[LabratSR]

Investigation into Building Frames around at Unit 1 Reactor Building Equipment Hatch


http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130918_17-e.pdf

 

[LabratSR]

I was poking around the Oak Ridge website and stumbled across this interesting report that was released in April.

Fukushima Daiichi – A Case Study for BWR Instrumentation and Control Systems Performance during a Severe Accident

http://info.ornl.gov/sites/publications/Files/Pub42256.pdf

 

[LabratSR]

Another typhoon headed in the general direction of Fukushima. More rain coming at the very least.

http://www.accuweather.com/en/weather-news/francisco-strengthen-japan-nex/18911396