Overview and status of the accident - International Atomic ... of Japan Contents 1. urrent Status of TEPO’s Fukushima Dai -ichi NPS 2. Investigation of causes of the accident and

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


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


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)


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.


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


Government of Japan


(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).


Government of Japan


• 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


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


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


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.


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.


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)


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


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)


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


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.


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


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


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


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


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.


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


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.


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


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)


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


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


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.


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)


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


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.


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


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


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)


http://www.meti.go.jp/press/2012/08/20120803005/20120803005.html

http://www.meti.go.jp/press/2012/08/20120803005/20120803005.html

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


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


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


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)


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)


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.


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 -


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 -


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.


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


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.


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 ~


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).


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.


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”


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.


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


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


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)


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”


Government of Japan

5. Conclusion


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

*


Government of Japan

Thank you for your kind attention !!


Documents

Overview and status of the accident - International Atomic ... of Japan Contents 1. urrent Status of TEPO’s Fukushima Dai -ichi NPS 2. Investigation of causes of the accident and