1. Notes
Status of the Efforts towards the Decommissioning of Fukushima Daiich NPS Units 1-4, as of March 6, 2013. (compiled by JAIF)
Plant related parameters Fukushima Daiichi NPP:
http://www.tepco.co.jp/nu/fukushima-np/
roadmap/images/d130307_01-j.pdf
(Japanese)
TEPCO releases the Fukushima Nuclear Accidents
Investigation Report on June 20.
http://www.tepco.co.jp/en/press/corp-com/
release/2012/1205638_1870.html
The National Diet of Japan Fukushima Nuclear Accident
Independent Investigation Commission releases the official
report on July 5. http://naiic.go.jp/en/report/
The Investigation Committee on the accidents at the
Fukushima NPS releases Final Report on July 23.
http://icanps.go.jp/eng/final-report.html
◇Water level from the bottom of the PCV
Unit 1 : 2.8m
Unit 2 : 0.6m
Unit 3 : unconfirmed
Result of radioactive nuclide analysis for the seawater
sampled at intake canal of Fukushima Daiichi NPP port.
[sampled on March 6]：
http://www.tepco.co.jp/en/nu/fukushima-np/
f1/smp/2013/images/intake_canal_130307-e.pdf
Estimation of radioactive materials released into the atmosphere
between Mar. 12 and 31, 2011. (TEPCO report on May 24): I-
131=about 500PBq, Cs-134=about 10PBq, Cs-137=about 10PBq
Radiation dose rate measured at the boundary of the Fukushima
Daiichi NPP (monitoring post): 2.7-6.8μSv/h (at 12:00 on March 6)
http://www.tepco.co.jp/en/nu/fukushima-np/f1-rt/html-e/f1-mp-
20130306-e.html
Plant Status
Timed Targets
(TT)
Plant Status
Status of the Efforts towards the Decommissioning of Fukushima Daiich NPS Units 1-4
d. Almost all of pressure proof hose to polyethylene pipe will be replaced by the end of December. Replacement of a part of remaining areas will be finished by mid-FY2013.
e. Change of intake sources for circulating water cooling from Buffer tank to CST to increase the capacity and make earthquake more resistant will be finished in June 2013.
f. Nitrogen injection into S/C in order to purge hydrogen which had assumed at the time of the initial accident: Nitrogen injection has been continued st Unit 1, and will start after mid-March
at Unit 2.
Reduce the risk of expanded seawater contamination while reducing radioactive material concentrations in seawater in the port.
1) Installation of water shielding walls in front of Units 1‒4 by mid-FY 2014, to prevent contaminated underground water from flowing into the sea.
2) Rapidly reducing radioactive substance concentrations in seawater in the port below the legal density limit for out of supervised areas, by mid-FY 2012.
a. Installation works of the water shielding walls in front of the Units 1‒4 started in October 2011, and entered into a full scale steps in April 2012. The works take place as planned.
b. Cs legal density limit was not achieved at some locations, including inside the silt fences of the Units 2 ‒4. The method to clean up Cs and Sr is under consideration with cooperation from
external organizations.
◇The maximum concentration of radioactive materials in the seawater within the Fukushima Daiichi NPS port (Bq/ ℓ):
31（Cs134）, 64（Cs137） [sampled on March 6 at Unit 3 screen (inside the silt fence)] ＊The legal density limit for out of supervised areas: 60(Cs134）, 90（Cs137）
Stably cooling SFP water of Units 1-4 with a circulation cooling system (Most spent fuels estimated to be undamaged)
Purification of the SFP water with desalination equipment is implemented step by step at Units 2-4, at which seawater was injected in to the SFP, to prevent corrosion of components.
Temperatures of SFP water of Units 1-4 are 10-21℃ (at 11:00, March 6)
Ⅲ． Radioactive Waste
Management and Dose
Reduction at the Site
Boundaries
Plant Status
Radioactive materials and radioactively contaminated debris scattered due to the hydrogen explosion. Splaying dispersion inhibitor and removing debris are in progress.
Installation of Unit 1 R/B cover was completed in October 2011. Installation work of Unit 4 R/B cover for removal of fuels, including foundation improvement work began on April 17.
PCV gas control systems in operation at Units 1, 2 and 3 to suppress the release of gaseous radioactive materials from PCVs.
Progress of
measures
towards TT
Ⅳ． Fuel Removal from the Spent
Fuel Pool
Plant Status
Occupational Safety
Assurance (Radiation
Exposure of Workers)
◇On February 28, TEPCO released a monthly report of the occupational radiation exposure dose at the Fukushima Daiichi NPS. A total of 25,837 workers were there during the period from
March 2011 to January 2013. The maximum cumulative dose was 678.80 mSv and the average dose was 11.88mSv. A total of 5,702 workers were there in January, 439 of which were new
workers. The maximum and average doses in January were 12.65mSv and 0.86mSv.
As usage of APD shielded with lead cover was unveiled, reevaluation of employees' radiation exposure levels was conducted and recurrence prevention measures was established. Workers
engaged in works under high level radiation have worn protective clothings with a transparent chest part since October 15. All workers have done the same since February 2013.
Timed Targets
(TT)
"Cold shutdown condition" is maintained at Units 1-3. By means of a circulating injection cooling system, huge amount of the highly radioactive waste water, which is accumulated in the
basement of the R/Bs and T/Bs of Units 1-4, is being processed and injected into the reactor to cool down the damaged, melted core.
◇Temperatures of the bottom of RPVs and gas-phase parts of PCVs: nearly 15-35℃ (on March 6).
◇Reactor injection flow rate via feed water line / via core spray line (m3/h) : Unit 1: 2.5/2.0, Unit 2: 2.0/3.6, Unit 3: 0.0/5.5 (at 11:00, March 6)
Continually monitor stable "cold shutdown condition" by continuing water injection cooling till completion of the fuel debris removal.
1) Consider and implement methods to improve the reliability of the existing water processing and injection cooling facilities within FY2012, and continue improvements thereafter.
2) By the end of FY2012, start operation of multi-nuclide removal facilities removing radioactive materials other than Cs, which are difficult to remove with the existing facilities.
3) Scale down the circulation loop in stages, according to improvement of the reliability of the existing water processing facilities and measures in Phase 2, such as stopping inter-building
water leakage and repairing lower part of the PCV.
a. Construction of 80,000m3 processed water tanks will be completed in mid-2013, and of additional 300,000m3 tanks is planned, resulting in the total capacity of 700,000m3 by mid-2015.
*Situation of storage of processed water as of March 5 : Storage volume / Storage capacity (m3) , 266,121 / 314,800, 400m3/day of water inflows.
b. Construction of the multi-nuclide removal equipment (ALPS) has been completed. Hot test operation using radioactive water is in preparation, before full operation.
c. A system to prevent groundwater from infowing into buildings by pumping the groundwater upstream (groundwater bypass) has been almost completed. The result of water quality
analysis is no problem. The system including the discharge equipment will operate gradually.
Ⅱ． Mitigation of the Sea Water
Contamination
◇Procedures: rubbles removal ⇒ installation of cover and
crane ⇒ fuel removal
◇Construction work for the temporary dry cask storage
facility began in August 2012 in order to receive some
spent fuels of the shared SFP.
Water including high concentration of radioactive materials flowed from the NPS into the front sea in April and May, 2011. A variety of measures have been taken to prevent radioactive
materials from flowing into the underground water and the sea while decontaminating the seawater with circulating seawater purification facilities..
Progress of
measures
towards TT
a. The works of soil covering and water shielding are under way at the two temporary waste storage facilities which have received rubbles.
b. Closing the opening of blowout panel of Unit 2 R/B is scheduled to be completed in March 2013.
◇The release rate of radioactive materials from Units 1-3 PCVs is estimated to be totally about 10 million Bq/h (Cs-134 and 137) at maximum, leading to the exposure of 0.03mSv/y at the
boundary of the site. ［TEPCO report on Match 7］
Timed Targets
(TT)
Properly manage and control solid, gaseous, liquid radioactive waste
1) Reducing the effective radiation dose at the site boundaries to below 1 mSv/year within FY2012, including effective dose due to additional release of radioactive materials from the NPP as
a whole, and radioactive waste produced after the accident and stored on the site (secondary waste from water processing, debris, etc.)
Ⅰ． Reactor Cooling /
Accumulated Water Processing
Progress of
measures
towards TT
Estimated amount of radioactivity discharged to the sea
from March 26 through Sept. 30, 2011（TEPCO, May 24,
2012）:
I-131: 11PBq, Cs134: 3.5PBq, Cs137: 3.6PBq
http://www.tepco.co.jp/en/press/corp-com/
release/2012/1204659_1870.html
Progress of
measures
towards TT
a. Removal of rubbles at the upper part of the R/Bs at Unit 4 finished on December 2012 . Units 3 will be completed in the end of FY 2012.
b. R/B cover for fuel removal of Unit 4 is being installed (to be completed in mid FY2013).
c. It is evaluated that desalination of Unit 1-4 SFP was completed. The pool water will be sampled regularly to examine its water quality.
◇ On September 22, during a rubble removal work of Unit 3, a worker tried to grab a steel beam (approx. 470kg) on the side of the SFP, and the steel beam slipped and fell into the SFP.
There has been no significant change in the nuclide analysis results of Unit 3 SFP water and the monitoring post data. On October 3 and 19, a report including the cause of the incident and
recurrence prevention measures was submitted to the Nuclear Regulation Authority. The steel beam was removed on December 20.
Timed Targets
(TT)
Complete fuel removal from SFP of all Units during Phase 2
1) Unit 4: Start fuel removal on November 2013,（Complete late 2014） 2) Unit 3: Start fuel removal within 2014
3) Units 1 and 2: Develop a fuel removal plan based on the situation of decontamination, removal of debris, etc., and remove fuels during Phase 2
[Source]
Ministry of Economy, Trade and Industry: http://www.meti.go.jp/earthquake/nuclear/decommissioning.html (Japanese)
TEPCO: http://www.tepco.co.jp/en/nu/fukushima-np/roadmap/conference-e.html#anchor02
[Abbreviations]
RPV: Reactor Pressure Vessel
PCV: Primary Containment Vessel
R/B: Reactor Building
T/B: Turbine Building
CST: Condensate water Storage Tank
SFP: Spent Fuel Storage Pool
NPS: Nuclear power station
TEPCO: Tokyo Electric Power Company
![Notes
Status of the Efforts towards the Decommissioning of Fukushima Daiich NPS Units 1-4, as of March 6, 2013. (compiled by JAIF)
Plant related parameters Fukushima Daiichi NPP:
http://www.tepco.co.jp/nu/fukushima-np/
roadmap/images/d130307_01-j.pdf
(Japanese)
TEPCO releases the Fukushima Nuclear Accidents
Investigation Report on June 20.
http://www.tepco.co.jp/en/press/corp-com/
release/2012/1205638_1870.html
The National Diet of Japan Fukushima Nuclear Accident
Independent Investigation Commission releases the official
report on July 5. http://naiic.go.jp/en/report/
The Investigation Committee on the accidents at the
Fukushima NPS releases Final Report on July 23.
http://icanps.go.jp/eng/final-report.html
◇Water level from the bottom of the PCV
Unit 1 : 2.8m
Unit 2 : 0.6m
Unit 3 : unconfirmed
Result of radioactive nuclide analysis for the seawater
sampled at intake canal of Fukushima Daiichi NPP port.
[sampled on March 6]：
http://www.tepco.co.jp/en/nu/fukushima-np/
f1/smp/2013/images/intake_canal_130307-e.pdf
Estimation of radioactive materials released into the atmosphere
between Mar. 12 and 31, 2011. (TEPCO report on May 24): I-
131=about 500PBq, Cs-134=about 10PBq, Cs-137=about 10PBq
Radiation dose rate measured at the boundary of the Fukushima
Daiichi NPP (monitoring post): 2.7-6.8μSv/h (at 12:00 on March 6)
http://www.tepco.co.jp/en/nu/fukushima-np/f1-rt/html-e/f1-mp-
20130306-e.html
Plant Status
Timed Targets
(TT)
Plant Status
Status of the Efforts towards the Decommissioning of Fukushima Daiich NPS Units 1-4
d. Almost all of pressure proof hose to polyethylene pipe will be replaced by the end of December. Replacement of a part of remaining areas will be finished by mid-FY2013.
e. Change of intake sources for circulating water cooling from Buffer tank to CST to increase the capacity and make earthquake more resistant will be finished in June 2013.
f. Nitrogen injection into S/C in order to purge hydrogen which had assumed at the time of the initial accident: Nitrogen injection has been continued st Unit 1, and will start after mid-March
at Unit 2.
Reduce the risk of expanded seawater contamination while reducing radioactive material concentrations in seawater in the port.
1) Installation of water shielding walls in front of Units 1‒4 by mid-FY 2014, to prevent contaminated underground water from flowing into the sea.
2) Rapidly reducing radioactive substance concentrations in seawater in the port below the legal density limit for out of supervised areas, by mid-FY 2012.
a. Installation works of the water shielding walls in front of the Units 1‒4 started in October 2011, and entered into a full scale steps in April 2012. The works take place as planned.
b. Cs legal density limit was not achieved at some locations, including inside the silt fences of the Units 2 ‒4. The method to clean up Cs and Sr is under consideration with cooperation from
external organizations.
◇The maximum concentration of radioactive materials in the seawater within the Fukushima Daiichi NPS port (Bq/ ℓ):
31（Cs134）, 64（Cs137） [sampled on March 6 at Unit 3 screen (inside the silt fence)] ＊The legal density limit for out of supervised areas: 60(Cs134）, 90（Cs137）
Stably cooling SFP water of Units 1-4 with a circulation cooling system (Most spent fuels estimated to be undamaged)
Purification of the SFP water with desalination equipment is implemented step by step at Units 2-4, at which seawater was injected in to the SFP, to prevent corrosion of components.
Temperatures of SFP water of Units 1-4 are 10-21℃ (at 11:00, March 6)
Ⅲ． Radioactive Waste
Management and Dose
Reduction at the Site
Boundaries
Plant Status
Radioactive materials and radioactively contaminated debris scattered due to the hydrogen explosion. Splaying dispersion inhibitor and removing debris are in progress.
Installation of Unit 1 R/B cover was completed in October 2011. Installation work of Unit 4 R/B cover for removal of fuels, including foundation improvement work began on April 17.
PCV gas control systems in operation at Units 1, 2 and 3 to suppress the release of gaseous radioactive materials from PCVs.
Progress of
measures
towards TT
Ⅳ． Fuel Removal from the Spent
Fuel Pool
Plant Status
Occupational Safety
Assurance (Radiation
Exposure of Workers)
◇On February 28, TEPCO released a monthly report of the occupational radiation exposure dose at the Fukushima Daiichi NPS. A total of 25,837 workers were there during the period from
March 2011 to January 2013. The maximum cumulative dose was 678.80 mSv and the average dose was 11.88mSv. A total of 5,702 workers were there in January, 439 of which were new
workers. The maximum and average doses in January were 12.65mSv and 0.86mSv.
As usage of APD shielded with lead cover was unveiled, reevaluation of employees' radiation exposure levels was conducted and recurrence prevention measures was established. Workers
engaged in works under high level radiation have worn protective clothings with a transparent chest part since October 15. All workers have done the same since February 2013.
Timed Targets
(TT)
"Cold shutdown condition" is maintained at Units 1-3. By means of a circulating injection cooling system, huge amount of the highly radioactive waste water, which is accumulated in the
basement of the R/Bs and T/Bs of Units 1-4, is being processed and injected into the reactor to cool down the damaged, melted core.
◇Temperatures of the bottom of RPVs and gas-phase parts of PCVs: nearly 15-35℃ (on March 6).
◇Reactor injection flow rate via feed water line / via core spray line (m3/h) : Unit 1: 2.5/2.0, Unit 2: 2.0/3.6, Unit 3: 0.0/5.5 (at 11:00, March 6)
Continually monitor stable "cold shutdown condition" by continuing water injection cooling till completion of the fuel debris removal.
1) Consider and implement methods to improve the reliability of the existing water processing and injection cooling facilities within FY2012, and continue improvements thereafter.
2) By the end of FY2012, start operation of multi-nuclide removal facilities removing radioactive materials other than Cs, which are difficult to remove with the existing facilities.
3) Scale down the circulation loop in stages, according to improvement of the reliability of the existing water processing facilities and measures in Phase 2, such as stopping inter-building
water leakage and repairing lower part of the PCV.
a. Construction of 80,000m3 processed water tanks will be completed in mid-2013, and of additional 300,000m3 tanks is planned, resulting in the total capacity of 700,000m3 by mid-2015.
*Situation of storage of processed water as of March 5 : Storage volume / Storage capacity (m3) , 266,121 / 314,800, 400m3/day of water inflows.
b. Construction of the multi-nuclide removal equipment (ALPS) has been completed. Hot test operation using radioactive water is in preparation, before full operation.
c. A system to prevent groundwater from infowing into buildings by pumping the groundwater upstream (groundwater bypass) has been almost completed. The result of water quality
analysis is no problem. The system including the discharge equipment will operate gradually.
Ⅱ． Mitigation of the Sea Water
Contamination
◇Procedures: rubbles removal ⇒ installation of cover and
crane ⇒ fuel removal
◇Construction work for the temporary dry cask storage
facility began in August 2012 in order to receive some
spent fuels of the shared SFP.
Water including high concentration of radioactive materials flowed from the NPS into the front sea in April and May, 2011. A variety of measures have been taken to prevent radioactive
materials from flowing into the underground water and the sea while decontaminating the seawater with circulating seawater purification facilities..
Progress of
measures
towards TT
a. The works of soil covering and water shielding are under way at the two temporary waste storage facilities which have received rubbles.
b. Closing the opening of blowout panel of Unit 2 R/B is scheduled to be completed in March 2013.
◇The release rate of radioactive materials from Units 1-3 PCVs is estimated to be totally about 10 million Bq/h (Cs-134 and 137) at maximum, leading to the exposure of 0.03mSv/y at the
boundary of the site. ［TEPCO report on Match 7］
Timed Targets
(TT)
Properly manage and control solid, gaseous, liquid radioactive waste
1) Reducing the effective radiation dose at the site boundaries to below 1 mSv/year within FY2012, including effective dose due to additional release of radioactive materials from the NPP as
a whole, and radioactive waste produced after the accident and stored on the site (secondary waste from water processing, debris, etc.)
Ⅰ． Reactor Cooling /
Accumulated Water Processing
Progress of
measures
towards TT
Estimated amount of radioactivity discharged to the sea
from March 26 through Sept. 30, 2011（TEPCO, May 24,
2012）:
I-131: 11PBq, Cs134: 3.5PBq, Cs137: 3.6PBq
http://www.tepco.co.jp/en/press/corp-com/
release/2012/1204659_1870.html
Progress of
measures
towards TT
a. Removal of rubbles at the upper part of the R/Bs at Unit 4 finished on December 2012 . Units 3 will be completed in the end of FY 2012.
b. R/B cover for fuel removal of Unit 4 is being installed (to be completed in mid FY2013).
c. It is evaluated that desalination of Unit 1-4 SFP was completed. The pool water will be sampled regularly to examine its water quality.
◇ On September 22, during a rubble removal work of Unit 3, a worker tried to grab a steel beam (approx. 470kg) on the side of the SFP, and the steel beam slipped and fell into the SFP.
There has been no significant change in the nuclide analysis results of Unit 3 SFP water and the monitoring post data. On October 3 and 19, a report including the cause of the incident and
recurrence prevention measures was submitted to the Nuclear Regulation Authority. The steel beam was removed on December 20.
Timed Targets
(TT)
Complete fuel removal from SFP of all Units during Phase 2
1) Unit 4: Start fuel removal on November 2013,（Complete late 2014） 2) Unit 3: Start fuel removal within 2014
3) Units 1 and 2: Develop a fuel removal plan based on the situation of decontamination, removal of debris, etc., and remove fuels during Phase 2
[Source]
Ministry of Economy, Trade and Industry: http://www.meti.go.jp/earthquake/nuclear/decommissioning.html (Japanese)
TEPCO: http://www.tepco.co.jp/en/nu/fukushima-np/roadmap/conference-e.html#anchor02
[Abbreviations]
RPV: Reactor Pressure Vessel
PCV: Primary Containment Vessel
R/B: Reactor Building
T/B: Turbine Building
CST: Condensate water Storage Tank
SFP: Spent Fuel Storage Pool
NPS: Nuclear power station
TEPCO: Tokyo Electric Power Company](https://image.slidesharecdn.com/decommissioning20130306-141029114306-conversion-gate01/85/Decommissioning-Fukushima-20130306-1-320.jpg)
