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Government of Japan
Overview and status of the accident at TEPCO’s Fukushima Dai-ichi NPS
and the activities taken in Japan
27 August 2012
2nd CNS Extraordinary meeting IAEA Headquarters, Vienna
Government of Japan
Contents
1. Current Status of TEPCO’s Fukushima Dai-ichi NPS
2. Investigation of causes of the accident and implementation of countermeasures based on the lessons learned (Topics 1 to 3)
3. New regulatory policy and framework (Topics 4 and 5)
4. Post-accident management (Off-site) (Topic 5)
5. Conclusion
27 August 2012 2nd CNS Extraordinary Meeting 1
Government of Japan
1. Current Status of TEPCO’s Fukushima Dai-ichi NPS Summary of the accident Summary of the accident
Current status of Fukushima Dai-ichi unit 1 to 4 Release Rate of Radioactive Materials from PCVs of Units 1-3
Situation of each unit Investigation Result of the Inside of Unit 1
Investigation Result of the Inside of PCV of Unit 2
Investigation Result of the Inside of Unit 3 Situation of SFP of Unit 4
Investigation of Unit 4 Reactor Building Tilt (Water Level Measurement)
Investigation of Unit 4 Reactor Building (Outer Wall Measurement) Installing Support Structures at Bottom of SFP of Unit 4
Investigation of seismic resistance of Unit 4 Reactor Building
Fuel removal and decommissioning Fresh Fuels Removal from SFP of Unit 4
Prepare for Fuel Removal from SFP of Unit 4 Mid-to-Long Term Roadmap towards the Decommissioning of Fukushima Nuclear
Power Units 1-4
27 August 2012 2nd CNS Extraordinary Meeting 2
Government of Japan
Summary of the accident (1)
Epicenter
Occurred 14:46, 11. March 2011 Magnitude:9.0 Mw Epicenter location: 38°6’’N and 142°51’’E,
and 24km in depth The height of tsunami attacked Fukushima –
Dai-ich was assumed more than 14m
Fukushima Dai-ni NPP Source: www.tepco.co.jp
Fukushima Dai-ichi NPP
Source: www.tepco.co.jp
27 August 2012 2nd CNS Extraordinary Meeting 3
Government of Japan
• The accident at Fukushima Dai-ichi NPS was caused by long lasting complete power loss due to common cause failure (CCF) of electrical equipment following tsunami, and insufficient provision against severe accident.
• It is temporarily rated at INES Level 7, and people where lived in the specific area including those within 20 km radius from the site are still not able to return home.
The moment when tsunami attacked Fukushima Dai-ichi NPS (Source: TEPCO)
Summary of the accident (2)
27 August 2012 2nd CNS Extraordinary Meeting 4
Government of Japan
TEPCO Ministry of Defense
Reactor Pressure
vessel -Water injection
- N2 injection
- Temp of reactor vessel
FW: 2.8m3/h
CS: 2.1m3/h N2: 12.39Nm3/h
39.0℃(bottom
head)
FW: 2.1m3/h
CS: 5.0m3/h
N2: 14.20Nm3/h
53.8℃(wall above
bottom head)
FW: 2.6m3/h
CS: 4.4m3/h
N2: 14.62Nm3/h
52.6℃(bottom
head)
No fuel
Primary
Containment
Vessel - N2 injection
- Air temp of PCV
N2: 19.59Nm3/h
Out: 40.8℃
In: 38.3℃
N2: 4.89Nm3/h
Out: 54.2℃
In: 53.0℃
N2: 0Nm3/h
Out: 48.2℃
In: 47.7℃
-
Fuel pool - Temperature of pool water
30.5℃ 31.2℃ 29.7℃ 38℃
Highly-contaminated
water in R/B and
T/B**
14,300 m3 23,400m3 25,600 m3 19,900 m3
Spent fuel
pool
Reactor pressure
vessel
Pressure suppression
chamber
Primary containment
vessel
Unit 1 Unit 2 Unit 3 Unit 4
* As of 11:00 on 20. Aug. 2012 ** As of 17. Jul. 2012
Current Status of unit 1 to 4
TEPCO Air Photo Service
5
Government of Japan
Release Rate of Radioactive Materials from R/Bs of Units 1-3 • Current total release rate of Cesium 134 and 137 from reactor buildings of Units1-3 is estimated to
be approx. 0.01 billion Bq/h at the maximum. (1/77,000,000 of early stages of the accident)
(Source: TEPCO )
Jul. Aug. Sep. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May Jun.
27 August 2012 2nd CNS Extraordinary Meeting 6
Government of Japan
Operator’s Investigation in R/B : Unit 1
• Investigation of the torus room by using endoscope system. (26. June 2012)
• Water level in torus room is approx. 5 m
• Water temperature is approx. 32 to 37 ℃ (room temperature is approx. 28.8 ℃)
• Dose rate of the torus room is 19.5 to 10,300 mSv/h.
(The result of measurement might not be accurate due to the failure of dose meter during the investigation.)
TEPCO conducted investigation inside the torus room by endoscope
• Endoscope • Thermo couple • Dosimeter
Suppression Chamber
Torus Room
27 August 2012 2nd CNS Extraordinary Meeting 7
Government of Japan
Operator’s Investigation in R/B : Unit 2
(Source: TEPCO)
<Industrial endoscope of 20m>
< Photos inside the PCV of Unit 2 >
RPV
PCV
• Endoscope • Thermo couple • Dosimeter
Approx 60cm
Above water surface
Under water surface
Wall of PCV
Thermo couple
By investigations using an
endoscope system, it was
confirmed that:
• Water level in PCV is approx.
60cm (26. Mar. 2012),
• Water temperature is approx.
50℃ (26. Mar. 2012), and,
• Dose rate of gas phase is
73Sv/h (27. Mar. 2012).
27 August 2012 2nd CNS Extraordinary Meeting 8
Government of Japan
Operator’s Investigation in R/B : Unit 3
• Investigation was done by remote controlled robot due to high dose rate was anticipated
• Dose rate inside the torus room is 100 to 360 mSv/h
• The investigation was aborted due to wired communication between controller and robot was ceased unexpectedly
TEPCO conducted investigation inside torus room using remote controlled robot in 11. July 2012
27 August 2012 2nd CNS Extraordinary Meeting 9
Government of Japan
• It was confirmed that the fuel assemblies in the spent fuel pool (SFP) of Unit 4 had
been stored in the racks and not severely damaged.
Situation of SFP of Unit 4
Unit 4 SFP
Screws
Camera
Light
Unit 4 SFP
Unit 4 SFP
(Source: TEPCO (Shot on 19-21 March 2012))
Unit 3 SFP Weld line
①south side wall ③inside of cask pit
Control rod, etc
Unit 4 SFP
debris
Fuel handle
Unit4 SFP
debris
Spent fuel rack
Cask pit ②debris and upper side of spent fuel
27 August 2012 2nd CNS Extraordinary Meeting 10
Government of Japan
Investigation of Unit 4 Reactor Building Tilt (Water Level Measurement)
• The distances between the floor surface and the water levels of the reactor well
and spent fuel pool are measured to check if the building is tilted or not.
• It has already been confirmed that the building is not tilted based on the
measurement results acquired on 7. February, 18. May and 12. April 2012.
Measurement Points (Floor surface of the 5th floor)
1) Building not tilted
The distance are the same
2) In Case of a tilt
There would be difference in the distances, → No such difference has been confirmed
27 August 2012 2nd CNS Extraordinary Meeting 11
Government of Japan
Investigation of Unit 4 Reactor Building (Outer Wall Measurement)
• In the west wall, partial deformation was confirmed, and the deformation
tendency was measured on 25. May 2012
• It has been confirmed so far that the deformation doesn’t affect structural
integrity of the building and SFP.
• Periodic inspection is continued.
27 August 2012 2nd CNS Extraordinary Meeting 12
Government of Japan
Finite element
analysis (horizontal
direction)
Investigation of seismic resistance of Unit 4 Reactor Building
• Various analyses have been conducted to investigate the tilt of U4 R/B and
confirm the seismic resistance.
27 August 2012 2nd CNS Extraordinary Meeting 13
Government of Japan
• It has been confirmed that the seismic resistance is sufficient without any
reinforcements.
• As a precautionary measure, support structures at the bottom of the pool has
been installed in order to further improve the safety margin in 2011.
Before steel pillar installation(May.31)
Placing concrete(Jul. 21)
Injection grount(Jul.30)
Installation steel pillar(Jun.20)
イメージ
コンクリート壁
使用済燃料プール
鋼製支柱
コンクリ トー壁
鋼製支柱
<コンクリート打設後>
<コンクリート打設前>
イメージ
コンクリート壁
使用済燃料プール
鋼製支柱
コンクリ トー壁
鋼製支柱
<コンクリート打設後>
<コンクリート打設前>
Install steel pillar
Install concrete wall
Installation image
Spent Fuel Pool
Concrete wall
Installing Support Structures at Bottom of SFP of Unit 4
Installation of support structures
(Source: TEPCO)
The upper floor of Unit 4 (Mar. 5, 2012)
27 August 2012 2nd CNS Extraordinary Meeting 14
Government of Japan
• Before installation of the covers, rubble will be removed from the upper part of the reactor building for Unit 3 and rubble removal was completed from Unit 4 on 11. July 2012.
Rubble Removal
Rubble and girder removal at Unit 4
Covering of SFP
Rubble removal at the top
Rubble removal at Unit 3
On 10. Sep. 2011
Removal works of the girder of overhead
traveling crane on 5. Mar. 2012
(Source: TEPCO)
On 17. Apr 2012
On 5. Jul. 2012
The protection platform added on
spent fuel pool to prevent rubble
falling into the spent fuel pool
Goal of completion around the
end of fiscal 2012
27 August 2012 2nd CNS Extraordinary Meeting 15
Government of Japan
• Removing fresh fuels experimentally from SFP of Unit 4 on 18. and 19. July 2012.
Fresh Fuels Removal from SFP of Unit 4
(Source: TEPCO)
27 August 2012 2nd CNS Extraordinary Meeting 16
Government of Japan
• Construction of covering structure was initiated from 17. April 2012.
• Removing fuels from SFP will be start in fiscal year 2013.
Prepare for Fuel Removal from SFP of Unit 4
Building image of fuel removal cover (Source: TEPCO)
Cross-section diagram
fuel removal cover
Measure for rain water
27 August 2012 2nd CNS Extraordinary Meeting 17
Government of Japan
Mid-to-Long Term Roadmap towards the Decommissioning of Fukushima Nuclear Power Units 1-4
-Commence the removal of fuels from the spent fuel pools (Unit 4 in 2 years)
Step 1, 2 Phase 1
Present (Step 2 Completed) Within 2 Years
<Achieved Stable
Conditions>
Reactors: A
condition
equivalent to
Cold Shutdown
Spent Fuel
Pools: More
stable cooling
Radioactive
Contaminated
Water: Reduction
of total amount
Period to the commencement of the fuel removal from the Spent Fuel Pools (Within
2 years)
Within 10 Years After 30-40 Years
Phase 2 Phase 3
Period to the commencement of the removal of fuel debris
(Within 10 years)
Period to the end of the decommissioning
(In 30-40 years)
-Reduce the radiation impact due to additional emissions from the whole site and radioactive waste generated after the accident (secondary waste materials via water processing and debris etc.) Thus maintain an effective radiation dose of less than 1 mSv/yr at the site boundaries caused by the aforementioned.
-Maintain stable reactor cooling and accumulated water processing and improve their credibility.
-Commence R&D and decontamination towards the removal of fuel debris
-Commence R&D of radioactive waste processing and disposal
-Complete the fuel removal from the spent fuel pools at all Units
-Complete preparations for the removal of fuel debris such as decontaminating the insides of the buildings, restoring the PCVs and filling the PCVs with water Then commence the removal of fuel debris (Target: within 10 years)
-Continue stable reactor cooling
-Complete the processing of accumulated water
-Continue R&D on radioactive waste processing and disposal, and commence R&D on the reactor facilities decommission
-Complete the fuel debris removal (in 20-25 years)
-Complete the decommission (in 30-40 years)
-Implement radioactive waste processing and disposal
Actions towards systematic staff training and allocation, improving motivation, and securing worker safety will be continuously implemented.
27 August 2012 2nd CNS Extraordinary Meeting 18
Government of Japan
2. Investigation of causes of the accident and implementation of countermeasures based on the lessons learned (Related Topics 1 to 3) Causes of the Accident NISA’s Technical Studies of the Accident
Impacts of Earthquake (Distribution of seismic intensity of seismic ground motion)
Abstract of Fukushima Dai-ichi NPS Progress of Accident (Outline of accident development common to Units 1 to 3)
Countermeasures in light of the accident of Fukushima Dai-ichi NPS Immediate Safety Measures (directed on 30. March 2011)
Measures to Upgrade Reliability of Power System (directed on 9. and 15. April 2011)
Severe Accidents Measures (directed on 7. June 2011) Review of the safety Restart of Seismic Backcheck Based on Knowledge of the Earthquake in March 2011 Stress Test in Japan
Countermeasures based on Technical Knowledge Learned
Decision Making on Restart of NPPs
27 August 2012 2nd CNS Extraordinary Meeting 19
Government of Japan
NISA’s Technical Studies of the Accident
• Technological Knowledge about the Accident at Fukushima Dai-ichi NPS
– NISA summarized the final report on 28. Mar. 2012
• Technological Assessment of the Aging and evaluated the Impact of the aging
– NISA summarized the assessment result on 16. Feb. 2012
• Assessment of Earthquake and Tsunami / Buildings and Structures – NISA compiled the interim report on 16. Feb. 2012
• Basic Approach for Regulation of Severe Accident – NISA summarized the basic approach on 23. Mar. 2012
27 August 2012 2nd CNS Extraordinary Meeting 20
Government of Japan
Impacts of Earthquake (Distribution of seismic intensity of seismic ground motion)
Reference: JMA “Tohoku District-Off the Pacific Coast Earthquake in 2011(1st Report),” http;//www.jma.go.jp/jma/index.html, partially modified by JNES
The boundary of the seismic intensity of 5 Onagawa NPS
Epicenter
Fukushima Dai-ichi & Dai-ni NPSs
Tokai Dai-ni NPS
JMA 1st report during the main shock
Seismic intensity
5- 5+ 6- 6+
Distribution of Seismic Intensity of Seismic Ground Motion in Tohoku District-Off the Pacific Coast Earthquake
27 August 2012 2nd CNS Extraordinary Meeting 21
Government of Japan
Abstract of Fukushima Dai-ichi NPS
Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6
Power output (10,000kW) 46.0 78.4 78.4 78.4 78.4 110.0
Date of commercial operation 1971/3 1974/7 1976/3 1978/10 1978/4 1979/10
Reactor type B WR3 B WR4 B WR5
Cooling type (High pressure system) IC, HPCI RCIC, HPCI RCIC, HPCS
Cooling type (Low pressure system) CS, SHC CS, LPCI LPCS, LPCI
Containment type MARK-1 MARK-2
Number of fuel assemblies 400 548 548 548 548 764
IC: Emergency condenser, RCIC; Reactor core isolation cooling system, HPCI: High pressure core injection system, HPCS: High pressure core spray system
CS: Core spray system, SHC: Reactor shutdown cooling system, LPCI: Low pressure core injection system, LPCS: Low pressure core spray system
Fukushima
Dai-ichi NPS
Fukushima
Dai-ni NPS
Unit 1
Unit 2
Unit 3
Unit 4
Unit 5
Unit 6
Niigata Prefecture
Tochigi Prefecture
Ibaragi Prefecture
Gunma Prefecture
Fukushima Prefecture
The
Pac
ific
O
cean
South Dike
Con
solid
ated
E
nviro
nmen
tal
Fac
ility
27 August 2012 2nd CNS Extraordinary Meeting 22
Government of Japan
Progress of Accident (Outline of accident development common to Units 1 to 3)
Automatic reactor shutdown due to earthquake, loss of off-site power supply
(Only one of emergency air cooling DGs in Unit 6 maintained its function)
Emergency diesel generator started up and power supply was secured.
Reactor was cooled by core cooling system.
Most of electric systems including emergency diesel generators and switchboards were unavailable due to tsunami.
Station Blackout
(On March 13, Unit 5 received power supply from Unit 6 on emergency basis. )
Water injection from fire protection system (Alternative water injection)
Hydrogen generated through zirconium – water reaction. Explosions that seemed to be hydrogen explosion occurred in reactor buildings at Units 1, 3 and 4. (Pressure in the pressure suppression chamber in Unit 2 dropped simultaneously with the Unit 4 explosion.)
Motor operated pumps etc. were unavailable. (Emergency cooling was carried out by emergency condenser IC in Unit 1, reactor core isolation cooling system [RCIC] in Unit 2, and RCIC and high pressure core injection system HPCI in Unit 3.)
Cooling sea water pumps installed along the coast were also unavailable. (Loss of heat sink) The exposure time of fuels is considered to be prolonged
due to insufficient reactor depressurization (reactor depressurization operation for containment, reactor containment depressurization [vent]) to the pressure lower than the fire extinguishing pump head.
Soaking / dry-up of battery, dry-up of compressed air, etc.
Many on-site works were necessary due to difficulty of measurement / control / communication.
Unit 1 has lost its function at an early phase. Due to this reason, there was only short time to address the situation.
Serious degradation of confinement led to the release of radioactive materials into environment.
The explosions deteriorated work performance in the surrounding areas.
Water leakage from containments / buildings were observed.
Dependency on emergency power was inevitable.
Start-up / Shutdown operations for IC・RCIC were going on.
Shutdown of core cooling system
Fuels were exposed and melt down while cooling was not conducted.
27 August 2012 2nd CNS Extraordinary Meeting 23
Government of Japan
Responses in light of the accident of Fukushima Dai-ichi NPS Conduct and ensure the following responses to the NPSs in light of the
accident of Fukushima Dai-ichi NPS.
Direct cause of expansion of the accident was loss of all power supply and core cooling functions induced by earthquake and tsunami, resulting in inability to cool the reactors, etc. Thus, measures shall be taken to stably cool the reactors, etc. even in case of the station blackout due to the attack of earthquake & tsunami equivalent to those at Fukushima Dai-ichi. Measures also shall be taken for protective means against tsunami and for diversity of emergency power system.
Immediate Safety Measures (incl. Protective measures against tsunami to
prevent station blackout etc.) Directed on 30. March 2011
Two units of emergency generators shall always be operable. Earthquake caused the collapse of mound and transmission towers,
and the power system shut-down stopped power supply to the nuclear facilities. Thus, reliability of power system shall be improved by making transmission lines and substations antiseismic.
Measures to upgrade reliability of power system
(Prevention of station blackout) Directed on 9. and 15. April 2011
Prevention of severe accidents
To prevent worsening of the condition due to hydrogen explosion and deteriorated working environment under severe accident, measures shall be taken to promptly respond even in case of a severe accident
(severe core damage, etc.). Severe accidents measures
Directed on 7. June 2011
Responses to be taken in case of severe accident initiation
27 August 2012 2nd CNS Extraordinary Meeting 24
Government of Japan
Implementation of Immediate Safety Measures (directed on 30. March 2011)
• In light of the accident of the reactors under operation and shutdown conditions at Fukushima Dai-ichi NPS of TEPCO, emergency measures shall be taken to prevent nuclear disasters similar to those at Fukushima Dai-ichi NPS, intended for all nuclear power stations nationwide.
Short-term measure: Securing of equipment (power vehicle, fire engine, fire hoses), Development of written procedures, Implementing appropriate drills
Mid-and-long term measure: Prompting of cold shutdown, Enhancement of protective means against tsunami
• During the process, it was decided that a conservative hypothesis should be taken so that a safer position would be accepted in all cases for uncertain matters. That is, we presumed that other NPSs may be attacked by tsunami equivalent to that at Fukushima Dai-ichi of TEPCO, and confirmed that safety is ensured (no damage of nuclear fuels) even under the following postulated condition:
(1) Regardless of the existence of plate boundary in the surrounding sea, tsunami with a postulated height, added 9.5 m to the previous postulated height, may attack.
(2) Three functions (all AC power, seawater cooling, spent fuel pool cooling) may be lost.
27 August 2012 2nd CNS Extraordinary Meeting 25
Government of Japan
Phase Immediate Safety Measures
Short Term Mid Term
Expected Time
to Completion Done One to three years
Goals(Desired
Level/Extent)
Preventing fuel damage and spent fuel damage
even if (1) AC power supplies, (2) seawater cooling
functions and (3) spent-fuel storage pool cooling
functions are all lost.
Enhancing reliability of emergency
safety measures (short term)
(Securing/speeding up achievement of
cold shutdown; measures against
tsunami)
Examples of
Specific
Measures
【Securing Equipment】 • Deploying power generator vehicles (to support
cooling reactors and spent fuel pools)
• Deploying fire engines (to supply cooling water)
• Deploying fire hoses (to secure water supply
routes from freshwater tanks, seawater pits, etc.)
【Preparing Procedural Manuals, Etc.】 • Preparing procedural manuals for emergency
responses utilizing the above-mentioned
equipment
【Training to Respond】 • Implementing training for emergency responses
based on the procedural manuals
【Measures Against Flooding】 • Measures to prevent flooding at reactor buildings
assuming approx. 15-meter-high tsunami
【Measures Against Assumed approx.15-
Meter Tsunami】 • Building seawalls
• Installing water-tight doors
【Measures to Secure/Speed Up
Achievement of Cold Shutdown】 • Installation of air-cooled diesel power
generators
• Securing back-up electric motors for
seawater pumps
• Actions needed for other necessary
equipment
Outline of Immediate Safety Measures
27 August 2012 2nd CNS Extraordinary Meeting 26
Government of Japan
Countermeasures for On-site Power Supply
125V battery charger room
Spare parts of electric motors and
replacement of pumps (Source: The
Chugoku Electric Power Co.,Inc.)
Watertight door (Source: The Shikoku Electric
Power Co.,Inc.)
Gas turbine generator (Source: The
Chugoku Electric Power Co.,Inc.) Emergency generator of cooling
methods through air cooling
(Source:The Chugoku Electric
Power Co.,Inc.)
Power supply inlets outside of the buildings
(Source: The Shikoku Electric Power Co.,Inc.) 250V battery charger room
spare parts
(electric motor)
Replacement
(pumps)
27 August 2012 2nd CNS Extraordinary Meeting 27
Government of Japan
Generator Vehicle (Source: TEPCO)
To support cooling reactors and spent fuel pools
Fire Engines (Source: TEPCO)
To supply cooling water
Countermeasures for Cooling Systems
27 August 2012 2nd CNS Extraordinary Meeting 28
Government of Japan
Implementation of Immediate Safety Measures (Heat removal function in PWR)
Pressurizer
Control rod
Water
Fuel
RPV
Steam
Wat
er
Turbine
PCV
Heat generated from fuels circulates in the primary
system
Heat transfer from the primary
to secondary system thru
steam generator
Transit the temperature in primary system
to a stable condition
Primary system
Secondary system removes heat by water
supply to steam generator and heat
discharge from the main steam safety relief valve
Power vehicle supplies power necessary for plant monitoring and operation of motor valves.
Pumper etc. supplies water
necessary for cooling
reactor and fuel pit.
Power vehicle
Seawater
Freshwater tank
Exit: Main steam safety relief valves (discharged from the
secondary system without radioactive materials)
Secondary system
Intake: Supply water from tank, regulating pond, and sea
Fuel pit
Pumper
Apply steam-driven pumps
Water
Steam generator
Coolant pump
Natural circulation
Main control room
27 August 2012 2nd CNS Extraordinary Meeting 29
Government of Japan
Ensuring Reliability of External Power Supply at NPPs
<Short term measures>
• NISA directed operators to install multiple emergency diesel generators, to
ensure common use of electric sources between units and power supply
vehicles in order to further enhance reliability based on assessments of the
electric power loss due to the Miyagiken-oki earthquake on 7. April 2011.
NISA confirmed their implementation.
<Mid term measures>
• NISA directed operators to connect all units to multiple power lines,
strengthen power lines and prevent flooding of the switchyard. Operators are
implementing these measures.
• NISA directed operators to evaluate seismic safety and take measures
securing switchyards against future possible earthquake. Operators are
implementing these measures.
27 August 2012 2nd CNS Extraordinary Meeting 30
Government of Japan
275kV air blast breaker (ABB) (Source: Electrical Equipment Earthquake Countermeasures WG)
A Countermeasure for External Power Supply
550kV gas insulated switchgear (GIS) (Source: Japan AE Power Systems Co. website)
27 August 2012 2nd CNS Extraordinary Meeting 31
Government of Japan
(1) Securing work environment at main control rooms In order to secure work environments in emergencies at central control rooms (radiation protection, etc.), emergency ventilation and air conditioning systems (circulation systems) for such control rooms must be operable with power from vehicle-mounted power generators even if all AC power supplies are lost.
(2)Securing means of emergency communication within plant premises In order to smoothly carry out work on plant premises during emergencies, robust means of communication must be secured even if all AC power supplies are lost.
(3)Securing supplies and equipment, including high-dose protective suits, and establishing a system to manage radiation
In order to ensure protection of workers against radiation and radiation management in emergencies, supplies and materials, including high-dose protective suits and individual dosimeters must be maintained, including arrangements for mutual accommodations among operators. Systems to increase personnel for radiation management at times of emergencies must be established.
(4)Measures to prevent hydrogen explosions In order to prevent damage to facilities by hydrogen explosions as a result of core damage, etc., large amounts of hydrogen generated in emergencies as a result of core damage, etc., must not be allowed to accumulate in reactor buildings, etc. (Operating annulus circulation and exhaust systems, etc.)
(5)Deploying heavy machinery to remove debris In order to promptly remove debris in emergencies, created by tsunami, etc., heavy machinery, including wheel loaders, must be deployed.
Measures for Severe Accidents
27 August 2012 2nd CNS Extraordinary Meeting 32
Government of Japan
Issues to be reflected on regarding the seismic safety evaluation based on the new findings drawn from the earthquake on 11th March 2011 (1)
The following new findings have been drawn from the earthquake and tsunami on 11th March :
(1) Concerning the fact that the earthquake was a trench-type earthquake, large seismic ground motions and tsunamis occurred due to an unexpected combination of movements of seismic segments.
(2) It was found out that a huge crustal seismic
deformation caused by the earthquake on 11th March 2011 induced activity in normal faults in the inland crust that had formerly been evaluated as less-active.
(3) A combination of long-period waves by the
quake in the deep trench between the plates and the short-period and great amplitude waves that occurred at the plate-boundary generated further increased the height of the tsunami.
27 August 2012 2nd CNS Extraordinary Meeting 33
Government of Japan
In evaluating the seismic ground motion of a trench type earthquake, the evaluation parameters (e.g. specifications of fault slips and asperity) with their maximum level should be reviewed. In addition, the directivity effect should also be considered.
The interaction of a fault 5 km or more away from other faults was denied empirically, but it should be re-examined, considering uncertainties.
Concerning the evaluation of estimated tsunami height, it is necessary to continue further examinations and reviews. As to the wave power evaluation, the design assumption of the pressure as three times as high as hydrostatic pressure is basically conservative; however, this may lead to underestimation depending on the conditions of the coastal topography.
Based on the new findings drawn from the earthquake on 11th March 2011, NISA conducted a review to reflect the findings on the seismic safety evaluation on nuclear power plants in tandem with the views from external experts. We have the following findings:
27 August 2012 2nd CNS Extraordinary Meeting
Issues to be reflected on regarding the seismic safety evaluation based on the new findings drawn from the earthquake on 11th March 2011 (2)
34
Government of Japan
Conducting the seismic safety evaluation based on the knowledge drawn from the earthquake on March 2011
In line with working on the issues that should be reflected on regarding the seismic safety evaluation, based on the earthquake on 11th March, NISA directed each operator to conduct the following: “Evaluation of the activities of faults which had been seen as inactive” (April and June 2011), “Evaluation of the ground motion and tsunami based on the knowledge of the earthquake on 11th March for NPSs which are largely impacted by a trench type earthquake“ (November 2011), “Re-evaluation of a combination of active faults that exist in the vicinity of the NPSs” (January 2012) and “Re-evaluation of the activation of the activities, etc. of fractured zones that exist in the premises of the NPSs” (July 2012).
NISA is examining the evaluation results in light of each plant while consulting with experts. Major issues to be considered : (1) Evaluation of an interaction of active faults (2) Re-evaluation of the activation of the activities of fractured zones that exist in the premises of the NPSs (3) Evaluation of stability of the backyard slopes of the reactor buildings
Future issues to be considered : (1) Evaluation method of earthquakes at the boundary of and within the plate and its evaluation of each plant (2)Evaluation method of tsunamis based on the knowledge of the earthquake on 11th March and its evaluation of each plant
27 August 2012 2nd CNS Extraordinary Meeting 35
Government of Japan
Stress Test in Japan
• Primary assessment: (Decision on whether to restart operations at nuclear power stations currently shut-down for periodic inspection)
Evaluate safety margins of safety systems, structures and components to endure the events beyond design bases, for nuclear power plants under periodic inspection and ready for start-up.
Finished for Ohi NPS Unit 3 and 4.
• Secondary assessment: (Decision on whether to continue or halt operations of nuclear power stations that are currently in operation)
Conduct comprehensive safety assessment to identify potential weak points for all nuclear power plants, as done in European Stress Test.
Expected to be Initiated in the near future.
Ohi NPS KEPCO
27 August 2012 2nd CNS Extraordinary Meeting 36
Government of Japan
Review Process of Stress Test in Japan
Licensee Power station (Unit) Date of report
on primary evaluation
Date of NISA’s evaluation completion
Date of report to
NSC
Date of NSC’s confirmation completion
Kansai Electric Power Co. Ohi Power Station (Unit 3) Oct. 28, 2011 Feb. 23, 2012 Feb. 23, 2012 Mar. 26, 2012 Shikoku Electric Power Co. Ikata Power Station (Unit 3) Nov. 14, 2011 Mar. 26, 2012 Mar. 26, 2012 — Kansai Electric Power Co. Ohi Power Station (Unit 4) Nov. 17, 2011 Feb. 23, 2012 Feb. 23, 2012 Mar. 26, 2012
Hokkaido Electric Power Co. Tomari Power Station (Unit 1) Dec. 7, 2011 Evaluation under way — — Kyushu Electric Power Co. Genkai Nuclear Power Station (Unit 2) Dec. 14, 2011 Evaluation under way — — Kyushu Electric Power Co. Sendai Nuclear Power Station (Unit 1) Dec. 14, 2011 Evaluation under way — — Kyushu Electric Power Co. Sendai Nuclear Power Station (Unit 2) Dec. 14, 2011 Evaluation under way — — Kansai Electric Power Co. Mihama Power Station (Unit 3) Dec. 21, 2011 Evaluation under way — — Japan Atomic Power Co. Tsuruga Power Station (Unit 2) Dec. 27, 2011 Evaluation under way — —
Hokkaido Electric Power Co. Tomari Power Station (Unit 2) Dec. 27, 2011 Evaluation under way — — Tohoku Electric Power Co. Higashidori Nuclear Power Station (Unit 1) Dec. 27, 2011 Evaluation under way — — Kansai Electric Power Co. Takahama Power Station (Unit 1) Jan. 13, 2012 Evaluation under way — — Tokyo Electric Power Co. Kashiwazaki-Kariwa Nuclear Power Station (Unit 1) Jan. 16, 2012 Evaluation under way — —
Tokyo Electric Power Co. Kashiwazaki-Kariwa Nuclear Power Station (Unit 7) Jan. 16, 2012 Evaluation under way — —
Kansai Electric Power Co. Ohi Power Station (Unit 1) Jan. 27, 2012 Evaluation under way — —
Hokuriku Electric Power Co. Shika Nuclar Power Station (Unit 2) Feb. 1, 2012 Evaluation under way — —
Hokuriku Electric Power Co. Shika Nuclar Power Station (Unit 1) Mar. 26, 2012 Evaluation under way — —
Kansai Electric Power Co. Takahama Power Station (Unit 4) Apr. 6, 2012 Evaluation under way — —
Kansai Electric Power Co. Takahama Power Station (Unit 3) Apr. 27, 2012 Evaluation under way — —
Kyushu Electric Power Co. Genkai Nuclear Power Station (Unit 4) May. 10, 2012 Evaluation under way — —
Kyushu Electric Power Co. Genkai Nuclear Power Station (Unit 3) May. 25, 2012 Evaluation under way — —
Shikoku Electric Power Co. Ikata Power Station (Unit 1) May. 25, 2012 Evaluation under way — —
Kansai Electric Power Co. Ohi Power Station (Unit 2) Jul. 20, 2012 — — —
Kansai Electric Power Co. Takahama Power Station (Unit 2) Aug. 3, 2012 — — —
Chugoku Electric Power Co. Shimane Nuclear Power Station (Unit 2) Aug. 3, 2012 — — —
Kyushu Electric Power Co. Genkai Nuclear Power Station (Unit 2) Aug. 13, 2012 — — —
• Currently 54 units of nuclear power plants are in operation. (The Units 1~ 4 at the TEPCO Fukushima Daiichi Nuclear Power Station were decided to be decommissioned .)
• 2 units (Ohi Power Station (Unit 3 and 4) are operating.
(As of August 13, 2012)
27 August 2012 2nd CNS Extraordinary Meeting 37
Government of Japan
Countermeasures based on Technical Knowledge Learned
Earthquake
Loss of External Power Supply
Tsunami
Loss of Emergency D/G
Core Damage
Hydrogen Explosion
Shut down
Start-up Emergency D/G and Core
Cooling System
Loss of Communication, Instrumentation
and Control System
<Accident Sequence> <Countermeasures> Prevention of Loss of Safety Functions by
Common Cause Failure
Prevention of severe accident
Mitigation of significant release of
radioactivity
1. Reliable external power supply and grid 2. Earthquake-resistant substation 3. Earthquake-resistant switching station 4. Quick recovery of external power supply
5. Dispersed power facilities 6. Water-tightening 7. Diversified and redundant emergency
power supply 8. Robust emergency DC supply 9. System-dedicated backup power supply
On-site Power Supply
Core Cooling / Injection
※Underlines mainly target BWR.
External Power Supply
Loss of DC
Loss of Core Cooling System
10. Facilitation of alternative power supply from outside
11. Storage of backup electrical equipments
CV Damage and Hydrogen Explosion Prevention
Communication, Instrumentation and Control
12. Improving response capabilities to accidents 14. Robust UHS at a time of accident 15. Reliable and controllable isolation valves 16. Alternative water injection functions 17. Reliable cooling and injection system for SFP
13. Dispersed cooling water system and water-tightening
19. Prevention of damage at the top-head flange of CV caused by overheating
22. Independent venting system 23. Decreasing release of radioactivity
when venting 24. Hydrogen explosion prevention
(control gas concentration and the adequate release )
18. Diversified CV cooling system 20. Surely switching to Low pressure
injection process 22. Reliable and controllable venting
system
25. Robust emergency command post 26. Reliable communication tools for
accidents 27. Reliable instruments for accidents 28. Robust plant parameter surveillance
functions 29. Robust radioactive monitoring
functions
30. Effective structure of emergency response system and training
38
Government of Japan
Meeting among Four Ministers on the Issue of Nuclear Power Stations
<Purpose> To make decisions on restart of NPPs on political level.
<Members> Prime Minister, The Chief Cabinet Secretary, Minister for Economy, Trade and Industry, Minister for the Restoration from and Prevention of Nuclear Accident
*Meetings were held so far on April 3, 5, 6, 9, 13, May 30 and June 16
Three Criteria for Safety Criterion 1 The licensee’s implementing safety measures to prevent consequences such as loss of all power sources caused by an earthquake or tsunami. *equivalent to short term measures in the “Immediate Safety Measures” (p.24)+ Criterion 2 The government’s making sure that an earthquake or tsunami as large as those attacked TEPCO’s Fukushima Dai-ichi NPS will not cause loss of cooling function for cores and SFPs nor any damage to the fuel in the plant. *equivalent to the primary assessment of “Stress Test” (p.33)+ Criterion 3 The licensee’s establishing an action plan on requirements identified through “Stress Test” and “Countermeasures based on Technical Knowledge Learned” (p.36) for further improving the safety and credibility of the plant, and demonstrating continuous improvement attitude.
Decision Making on Restart of NPPs
27 August 2012 2nd CNS Extraordinary Meeting 39
Government of Japan
Nuclear power utilities’ action plan (Criterion 3)
A. Plan of measures, based on the results of the primary assessment of stress tests by NISA.
B. Plan of measures included in the 30 safety measures described in the report “Technical
Knowledge about the Accident at Fukushima Dai-ichi Nuclear Power Station, Tokyo
Electric Power Co., Inc.” .
ex) Installation of seismic isolated building
(expected to go into operation in 2015)
ex) Disperse air cooled emergency power
generator equipment (expected to complete on
Oct. 2012)
image
ex) Enhance diversity and redundancy of
emergency power supply
ex) Mitigate the effect of radioactivity caused by
venting by installation of radioactive material
removal (filtering) facilities
(Source: KEPCO)
Air cooled emergency power generator
2015 FY
Filte
r
PCV
SG
R
P
V
venting stack
• Kansai Electric Power Co. has submitted the action plan to improve the safety and credibility of the Ohi Power Station U3 and 4 to Minister of Economy, Trade and Industry on April 9, including:
Permanent installed
Emergency DG
Installation of venting
facilities with filtering
function
40
Government of Japan
Restart of Ohi Power Station Unit 3 and 4
• 4 Ministers’ Meeting on 16. June 2012 has decided to restart of Unit 3 and 4 of Ohi Power Station.
• Under the constant monitoring by the Special Monitoring Framework which lead by the State Minister of Economy, Trade and Industry, the Unit 3 and 4 of Ohi Power Station has restarted.
<Unit 3>
1st of July: Start-up of reactor 9th of July: Reached the rated thermal power output
<Unit 4> 18th of July: Start-up of reactor 25th of July: Reached to the rated thermal power output
27 August 2012 2nd CNS Extraordinary Meeting 41
Government of Japan
3. New regulatory policy and framework (Related Topics 4 and 5)
Background of the Reform
Reform of organization New Nuclear Regulatory Organizations
Structure and Function of the NRA
(1) Independence of the NRA (2)Structure of the NRA
(3) Integration of Nuclear Regulation Functions
Reform of regulation (including off-site measures) New Nuclear Safety Regulation
- Amendment to the Nuclear Regulation Act – Solid Nuclear Emergency Preparedness System
(1)- Establishment of NEPC -
(2)~ Amendment to the Nuclear Emergency Act ~ Reform of Guidelines, etc. related Nuclear Safety and Nuclear Emergency Response
Actions to Be Taken
27 August 2012 2nd CNS Extraordinary Meeting 42
Government of Japan
Background of the Reform (1)
A public trust of nuclear safety policy has completely lost as a result of the accident at TEPCO’s Fukushima Nuclear Power Stations.
The overconfidence of the government and the licensee in their safety measures could not prevent severe accident, which causes massive discharge of radioactive materials to the environment and destroys communities of local citizens.
The government needs to reconstruct nuclear safety regulation organisation and regulation rapidly, so as to prevent severe accident.
Recommendation from Advisory Committee for Prevention of Nuclear Accident (December 2011)
27 August 2012 2nd CNS Extraordinary Meeting 43
Government of Japan
Report of Japanese Government to the IAEA Ministerial Conference on Nuclear Safety (June 2011)
It was not clear where the primary responsibility lies in ensuring citizen's safety in an emergency.
Also, we cannot deny that the existing organizations and structures hindered the mobilization of capabilities in promptly responding to such a large-scale nuclear accident.
• Separating nuclear regulation and promotion function • Integration of nuclear regulation functions • Strengthening crisis management • Reform nuclear regulation system
Background of the Reform (2)
27 August 2012 2nd CNS Extraordinary Meeting 44
Government of Japan NIRS
JAEA
NIRS
JAEA
Ministry of
Education,
Culture, Sports,
Science and
Technology
(MEXT)
Ministry of
Economy, Trade
and Industry
(METI)
Agency for
Natural
Resources and
Energy (ANRE)
Cabinet
Office
Nuclear Safety
Commission
(NSC)
Nuclear Regulation
Authority (NRA)
Commission: Chairman and
4 Commissioners
Independence: Separate nuclear regulation function and nuclear promotion function and establish the “Nuclear Regulation Authority (NRA)”, as an independent commission body affiliated to the MOE. Chairman and Commissioners are appointed by the Prime Minister after the approval of the National Diet.
Integration: Integrate nuclear regulation functions, namely, nuclear safety, security, safeguards, radiation monitoring and radioisotopes regulation, into the NRA.
Crisis Management: Establish “Nuclear Emergency Preparedness Commission (NEPC)” in a cabinet and implement nuclear emergency prevention measures in close cooperation with relevant organisations.
Nuclear and
Industrial Safety
Agency (NISA)
- Nuclear Power Plants
Regulation, etc.
New Organisation Current Organisations
Atomic Energy
Commission
(AEC)
- Nuclear Security
Policy
- Research Reactors
Regulation
- Safeguards *
- Radiation Monitoring *
- Radioisotopes
Regulation, etc. *
Ministry of the Environment (MOE)
Secretariat
JNES Nuclear Research, etc. *
Radiation Research, etc. *
* Transferred by 1st April 2013
Nuclear Research, etc.
Radiation Research, etc.
JNES
Double Checking
Merged into the NRA after
necessary legal arrangements
Independent Administrative Agencies
- JNES: Japan Nuclear Energy Safety Organisation
- JAEA: Japan Atomic Energy Agency
- NIRS: National Institute of Radiological Sciences
New Nuclear Regulatory Organization
45
Government of Japan
Structure and Function of the NRA (1) - Independence of the NRA -
Establish the NRA as an independent commission body.
Separate nuclear regulation function and nuclear promotion function. Separate the Nuclear and Industrial Safety Agency (NISA) from the Ministry of Economy,
Trade and Industry (METI).
Prohibit staffs of the NRA from transferring to the administrative
organisation for nuclear promotion, that is, apply “no-return-rule”. Completely prohibited 5 years after the formation of the NRA.
Provide guidance and standard for nuclear regulation independently.
Entitle the NRA to make recommendations to relevant Ministers for
ensuring nuclear safety.
Make new budget accounting classification, “nuclear safety regulation measure”, in the special account for energy resources.
27 August 2012 2nd CNS Extraordinary Meeting 46
Government of Japan
The NRA consists of the Commission (chairman and 4 commissioners) and the Secretariat.
The chairman and commissioners are selected from experts who have integrity and sufficient knowledge and experience of nuclear safety, and appointed by the Prime Minister after the approval of the National Diet. However, during nuclear emergency situation, the Prime Minister can appoint the
chairman prior to the ex post approval of the National Diet.
Decisions of the NRA are made by the vote of the Commissioners. However, during nuclear emergency situation, the chairman can make the NRA’s decisions
by him/herself.
1) Reactor Safety Examination Committee, 2) Nuclear Fuel Safety
Examination Committee and 3) Radiation Council are set under the NRA.
Structure and Function of the NRA (2) - Structure of the NRA -
27 August 2012 2nd CNS Extraordinary Meeting 47
Government of Japan
(1) Nuclear Safety (from METI, MEXT and MLIT) (2) Nuclear Security (from METI, MEXT and AEC) (3) Nuclear Safeguards (from MEXT) (4) Radiation Monitoring (from MEXT) (5) Radioisotopes Regulation (from MEXT) * Integration of the functions of the Nuclear Safety Commission (NSC)
• Terminate the NSC • Abolish the double-checking system • Integrate NSC’s necessary functions to the NRA (the NRA provide guidance
and standard for nuclear regulation)
Structure and Function of the NRA (3) - Integration of Nuclear Regulation Functions -
27 August 2012 2nd CNS Extraordinary Meeting 48
Government of Japan
New Nuclear Safety Regulation (1) - Amendment to the Nuclear Regulation Act -
(1) New regulation against severe accidents • Legally request severe accident measures to the licensees. • Introduce new legal requirement for visualising NPP’s safety and security information.
(2) Regulation system based on the latest scientific / technical knowledge
• Develop new technical standards for nuclear safety based on the latest scientific / technical knowledge and apply to existing licensed nuclear facilities as a legal obligation (back-fitting).
• Introduce type certification system for specific equipment which clearly improves safety of nuclear facilities.
• Introduce reporting system for modification of specific equipment of nuclear facilities which clearly improves safety.
27 August 2012 2nd CNS Extraordinary Meeting 49
Government of Japan
New Nuclear Safety Regulation (2) - Amendment to the Nuclear Regulation Act -
(3) 40-years operational limit for NPPs • Legally set the limit for NPP’s operation to 40 years from the passed date of its pre-service
inspection. • However the NRA can give permission to extend operational limit of NPPs by certain period
(not longer than 20 years, which will be defined by the Government Order) only once. • This permission is given only if NPPs comply with technical standard made by the NRA,
which checks its safety considering aging of nuclear facilities by long time operation.
(4) Special safety regulation for disaster-experienced NPPs (e.g. TEPCO’s Fukushima Dai-ich NPP)
• The NRA can specify a disaster-experienced, which needs special measures to prevent further disaster and to ensure nuclear security.
• The NRA request a licensee of the specific NPP to prepare implementation plan and take measures based on the plan.
(5) Legislative arrangement of nuclear safety regulation for NPPs
27 August 2012 2nd CNS Extraordinary Meeting 50
Government of Japan
Solid Nuclear Emergency Preparedness System (1) - Establishment of NEPC -
Establish the Nuclear Emergency Preparedness Commission (NEPC) under the Cabinet.
The NEPC promote 1) nuclear emergency preparedness measures based on the guidance for nuclear emergency preparedness, provided by the NRA, and 2) long-term comprehensive measures after nuclear disaster, in close cooperation with relevant organisations.
The NEPC consists of: • chairman (the Prime Minister) • vice chairmen (Chief Cabinet Secretary, Minister of Environment and Chairman of the
NRA) • members (the rest of the Ministers, etc.)
Minister of Environment also works as a secretary-general of the NEPC.
The Cabinet Office (CAO) is responsible for nuclear emergency preparedness measures and supports the secretary-general of the NEPC.
27 August 2012 2nd CNS Extraordinary Meeting 51
Government of Japan
(1) Provision of the guidance for nuclear emergency preparedness • The NRA will provide the legal-based guidance for nuclear emergency preparedness.
(2) Strengthening nuclear operator disaster prevention drills
• The NRA can check and review disaster prevention drills by licensees and give orders for necessary improvements.
(3) Reinforcing the Nuclear Emergency Response Headquarters (4) Facilitation of post-accident countermeasures (5) Clarification of mandate of the Prime Minister at nuclear emergency
• Safety issues on nuclear facilities, which the NRA should make judgements from technical and professional perspectives, are excluded from the mandate of the Prime Minister’s instructions at emergency.
Solid Nuclear Emergency Preparedness System (2) ~ Amendment to the Nuclear Emergency Act ~
27 August 2012 2nd CNS Extraordinary Meeting 52
Government of Japan
Reform of Guidelines, etc. related Nuclear Safety and Nuclear Emergency Response
• The NSC started to review the Regulatory Guide for Reviewing Seismic Design based on the accident, and released the draft revision of necessary matters for the treatment and the evaluation of tsunami.
• The NSC examined the Regulatory Guide for Reviewing Safety Design of Light Water Nuclear Power Reactor Facilities, and re-organized the basic principles of the measures for the loss of total AC power supply and the loss of ultimate heat sink.
• The NSC made policy that safety-securing measures should be enhanced with respect to “prevention of occurrence of severe accidents and mitigation of its effects”, including expansion of regulatory requirements and scope of subjects for confirmation.
• The NSC conducted a study on the re-examination of the “Emergency Preparedness and Response at Nuclear Facilities, etc.”, and proposed the principles that the Precautionary Action Zone (PAZ) should be roughly 5 km, the Urgent Protective Action Planning Zone (UPZ) be roughly 30 km, and the Plume Protection Planning Area (PPA) be roughly 50 km (reference value).
27 August 2012 2nd CNS Extraordinary Meeting 53
Government of Japan
Actions to Be Taken
• Selection and the National Diet approval of the chairman and
commissioners of the NRA.
• Establishment of solid nuclear emergency preparedness system.
• Further Integration of nuclear regulation functions, namely,
safeguards, radiation monitoring, radioisotopes regulation (as of
1st April 2013).
• Enforcement of New Nuclear Regulation (step by step after 10 or
15 months of the formation of the NRA).
• Merger of the JNES into the NRA (after legal arrangements).
• Development of human resources and safety culture.
• Continuous improvement of nuclear regulation organisation and
system.
27 August 2012 2nd CNS Extraordinary Meeting 54
Government of Japan
4. Post-accident management (Off-site) (Related Topic 5)
Radioactive materials spread widely including to the area in NW
direction where high dose areas are distributed
Redefine the Evacuation Zones
Framework of Decontamination
Special Decontamination Area and Intensive Contamination Survey Area
Decontamination Policy for Special Decontamination Area
Decontamination Policy for New Evacuation Zones
Decontamination Activities by Model Projects
“Interim Storage Roadmap”
27 August 2012 2nd CNS Extraordinary Meeting 55
Government of Japan
Monitoring results (Air dose rate)
* Based on airborne monitoring survey by MEXT (published on Sep. 12, 2011)
Legend Air dose rate on the points of 1 m high from surface ground [μSv/h] (Aug. 28,
2011)
Radioactive materials spread widely including to the area in NW direction where high dose areas are distributed.
27 August 2012 2nd CNS Extraordinary Meeting 56
Government of Japan
Redefine the Evacuation Zones
New zonings are defined and partially implemented from April 2012. Decontamination works will be conducted as necessary.
• Restricted Area (<20km)
• Planned Evacuation Area (>20mSv/y)
• Difficult-to-return Area (>20mSv/y even after 5yrs, or >50mSv/y)
− Access restriction: Same as Restricted Area
− Decontamination: Model project will be conducted in this year.
• Restricted Residential Area (>20mSv/y)
− Access restriction: Same as Planned Evacuation Area
− Decontamination: Initiated from 2012-2013.
• Evacuation-order-cancel Preparation Area (<=20mSv/y)
− Access restriction: Passing through and day trip home are possible.
− Decontamination: Initiated within 2012.
57
Government of Japan
104 municipalities in 8 prefectures (*), in which over 0.23 μSv/hour of air dose rate
(equivalent to over 1 mSv/Year) is surveyed, were designated. Decontamination is implemented by each municipality in accordance with its
implementation plan, which is prepared based on the result of survey, etc. The national government will take financial and technical measures.
(*) Iwate, Miyagi, Fukushima, Ibaraki, Tochigi, Gunma, Saitama, and Chiba
11 municipalities in Fukushima prefecture (*), which are located in (former)
restricted zone or planned evacuation zone, were designated. Decontamination is implemented by the national government in accordance with
the implementation plan, which is prepared for each municipality taking into account its opinion.
(*) Entire area of Naraha, Tomioka, Okuma, Futaba, Namie, Katsurao, and Iitate.
Some area of Tamura, Minami Soma, Kawamata, and Kawachi.
Framework of Decontamination Decontamination work has been planned and implemented in accordance with the Act on Special
Measures Concerning the Handling of Radioactive Pollution, that came into force on January 1, 2012. Priority is given to areas where decontamination is needed from the viewpoint of human health
protection. Removed soil, etc. generated from decontamination work is to be collected, transferred, temporally stored, and disposed safely based on the Act.
Special Decontamination Area
Intensive Contamination Survey Area
58
Government of Japan
Special Decontamination Area and Intensive Contamination Survey Area
Fukushima
Tochigi
Gunma Fukushima
NPP1
Chiba
Iwate
Miyagi
Ibaraki Saitama
Intensive Contamination Survey Area
Special Contamination Survey Area
27 August 2012 2nd CNS Extraordinary Meeting 59
Government of Japan
Decontamination Policy for Special Decontamination Area
Decontamination will be implemented in accordance with implementation plans of each municipality, taking into account the level of air dose rate.
Area less than 20mSv/year: Decontamination will be implemented, aiming for reducing additional exposure dose less than 1mSv/year as long-term goal.
Area from 20~50mSv/year: Decontamination will be implemented, aiming for reducing exposure dose in residential and farmland area less than 20mSv/year by the end of FY 2013.
Area more than 50mSv/year: Demonstration projects will be implemented. Lessons learnt will be reflected into future decontamination policy.
Policy in FY 2012 and 2013
Aiming for reducing additional exposure dose less than 1mSv/Y as long-term goal Check and evaluate two-year decontamination results, consider proper actions, and revise implementation plans as needed.
Policy After FY 2014
27 August 2012 2nd CNS Extraordinary Meeting 60
Government of Japan
FY 2011 FY2012 FY2013 FY
2014- Jan -Mar April July Oct Jan April July Oct Jan
Full-scale d
eco
ntam
inatio
n
Areas not
more than 20 mSv/yr
Areas with
20-50 mSv/yr
Areas >50
mSv/yr
Temporary storage
Decontamination Policy for New Evacuation Zones
Design Surveys and preparation
(in the order agreed by the community) Delivery and management
Areas with 5-10mSv/yr
Areas with 1-5 mSv/yr
Areas with 20-50 mSv/yr
Demonstration Works
Areas with 10-20 mSv/yr (Schools with 5-20 mSv/yr)
Verification of the results
61
Government of Japan
Decontamination Activities by Model Projects
roof:water cleaning, cleaning with brush
Concrete floor: High-pressure water cleaning
Garden:removal of topsoil
wall:wiping Gutter (vertical):high-pressure water cleaning
Concrete floor: Surface grinding
machine
〈Residential land〉
Concrete floor: Shot blast
Reference: Decontamination model project (JAEA)
27 August 2012 2nd CNS Extraordinary Meeting 62
Government of Japan
• Temporal storage: about 3 years
– Placed In each municipality or community
– In Special Decontamination Areas: MOE builds facilities
– Other areas: municipalities builds ones with financial and technical support from MOE
• Operation of Interim Storage Facilities: (start in 3 years, for less than 30 years)
– Placed in Fukushima Pref. (for waste and soil generated in the pref.)
– Select site in FY 2012
Negotiation has started with 8 municipalities since January
– Final disposal: outside Fukushima Pref.
– Other pref. : use existing waste disposal facilities in each pref.
Treatment flow in Fukushima prefecture 1. Generation
of waste
2. Temporal storage site
3. Intermediate storage site
4. Final disposal (outside)
Released by MOE on Oct 29, 2011
“Interim Storage Roadmap”
27 August 2012 2nd CNS Extraordinary Meeting 63
Government of Japan
5. Conclusion
27 August 2012 2nd CNS Extraordinary Meeting 64
Government of Japan
Conclusion
• Ensure steady progress on the decommissioning of Fukushima Dai-ichi Nuclear Power Station with safety and high credibility and promote post-accident off-site management
• Establish the new regulatory system including emergency preparedness and response based on the lessons learned derived from the accident, considering investigation reports*
• Share the knowledge and experience with international community
65
• “Investigation Committee on the Accident at the Fukushima Nuclear Power Stations of TEPCO”
– An interim report was published on Dec. 26, 2011
– The final report was published on Jul. 23, 2012
• “National Diet of Japan Fukushima Nuclear Accident Independent Investigation”
– A report was published on Jul. 5, 2012 2012
• “Independent Investigation Commission on the Fukushima Daiichi Nuclear Accident”
– The report was published on Mar. 11, 2012
*
27 August 2012 2nd CNS Extraordinary Meeting
Government of Japan
Thank you for your kind attention !!
27 August 2012 2nd CNS Extraordinary Meeting
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