The 5th International Forum on the Decommissioning of the Fukushima Daiichi Nuclear Power Station

Efforts to Ensure Safety in Decommissioning (No.1)
Safety Management of the Power Station

November 1, 2021
Tomohiko Isogai
Superintendent of Fukushima Daiichi Nuclear Power Station
Executive Vice President
Fukushima Daiichi Decontamination &Decommissioning Engineering Company
Tokyo Electric Power Company Holdings, Inc.
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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Overview of the Fukushima Daiichi Nuclear Power Station
Reactor building

Spent fuel pool

Reactor containment vessel
Reactor pressure vessel
Gas control
Nitrogen injection

Felled trees Protective Rubble

Turbinebuilding

clothing

Excavated soil

Ground water/rain water

Reactor injection

Water injection pump

Secondary waste fromwater treatment

ALPS
treated water

DebrisDesalination
systemCesiumremoval unit

Tank forwater injection

Multi-nuclide
removal facility©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Strontium
removed water

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Secondary waste fromwater treatment

1Safety Management of the Power Station
Measures against
earthquake andtsunamiIndustrial safety

Storagemanagement
Waste
generation
control
Dose reduction
Exposurecontrol
Environmental
monitoring

Naturaldisasters

Measures against
heavy rain

Fuel removal

NuclearsafetyFuel debris retrieval
Waste management

Risk management
Waste
management

Safety regarding thedecommissioning project
and the power station

Radiologicalcontrol©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Measures against contaminated water

Operational
management

Operations
management

Plant
maintenance

Nuclear security

Physicalprotection

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Nuclear disasterprevention

2

1. Risk Management (risk reduction)©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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1-1. Mid-and-long-term Roadmap
Revised Mid-and-long-term Roadmap (December 27, 2019), schedule for goals(milestones)
December
2011
Initiatives for stabilization

Achieve state of cold
shutdown

・Drastic suppression of release

Initiate removal at Unit 4
November 2013

Stage 1

Period until
removal of spent
fuel is initiated(within 2 years)

Stage 2
Period until retrieval offuel debris is initiated(within ten years)

Measures against contaminated water・Suppress volume of contaminated water generated to approx. 150 m3/day

By the end of 2020・Suppress volume of contaminated water generated to 100 m3/day or lessBy the end of 2025

・Complete treatment of stagnant water in buildings

By the end of 2020

・Reduce the volume of stagnant water in the Reactor Building by about half

FY2022-2024

Removal of fuel in spent fuel pool・Complete installation of large cover on Unit 1・Initiate fuel removal in Unit 1・Initiate fuel removal in Unit 2・Complete fuel removal in Units 1-6©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

December 2021 End of 2031

around FY2023
FY2027-2028
FY2024-2026
within 2031

30-40 years after
cold shutdown

Stage 3
Period until the decommissioning
project is concluded(after 30-40 years)

Stage 3-1

Retrieval of fuel debris

・Initiate retrieval of fuel debris from the initial unit
By the end of 2021
(Start with Unit 2. Expand the scale of retrieval in stages)

Radioactive solid waste management

・Technical outlook regarding measures for treatment/
disposal and their safety
Around FY2021
・Eliminate temporary outdoor storage of rubble etc.
By the end of FY2028

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1-2. Mid-and-long-term Action Plan (example of debris retrieval)Mid-and-long term (FY2024-end of 2032)

Short term (recent three years)

Initiate retrieva of fuel debris in first unit
(by the end of 2021)

RM
milestone*Expected to be delayed by about a year due tothe spread of the novel coronavirus

Improve environment
inside buildings

Trial retrieval(Unit 2)
Manufacture and installation of

Trial retrieval, internal survey
Analyze propertiesof fuel debris

equipment used for removal

Expand thescale ofretrieval instages(Unit 2)Further
expansion of
the scale ofretrieval(Units 1 and 3)

Improve environment
inside buildings

Fuel debris removal equipment/safety system/
fuel debris temporary storage facility/maintenance facility

Design and manufacture

Installation<Notes>• Understanding of status inside the PCV islimited(e.g.: structures in the PCV, properties of thefuel debris, etc.)• Progress in research and development oftechnology necessary for retrieval, etc. islimited (e.g.: technology for remote
installation of large retrieval equipment,
etc.)→Retrieval methods and work to be
performed shall be constantly reviewed
while considering the points above andnew knowledge acquired from future
survey, removal, analysis, etc.

Expand the scaleof retrieval in stages
Analyze propertiesof fuel debris

Building interior: dose reduction/removal of interfering objects, etc.
Building exterior: removal of Units 1/2 exhaust stack/removal of
Improve environment inside/outside buildingstransformer, etc.

Unit 1

Building interior: decrease in PCV inventory/dose reduction, etc.
Building exterior: removal of Units 3/4 exhaust stack/removal of
Improve environment inside/outside buildingstransformer, etc.

Unit 3

Fuel debris removal equipment/safety system/fuel debris temporary storage facility/maintenance facility/Training facility, etc.*

Review concepts

Verify field applicability,
development (remote installation,
dust suppression, etc.)

DesignManufacture/installation/removal*Reviews shall first be conducted for Unit 3, and later applied to Unit 1©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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2. Plant Maintenance©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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2-1. Plant Maintenance (long-term maintenance management plan)
Established a long-term maintenance management plan (fully implemented from January 2021): Considering the environmental changes after the earthquake, TEPCO identified significant risks to be focusedon for conducting decommissioning work and contaminated water management and decided to take action
against age degradation factors such as stress cracking and wear, etc., for the equipment concerned
Approx. 340,000 cases were identified inequipment and parts comprising eachsystem and have been continuously
managed with immediate temporary
measures being implemented andpermanent measures planned. Facilities
and buildings newly installed or removed
are also included in the reviews conducted
every fiscal year.

① Environmental impact (including exposure of the public and workers)(1) Loss of boundary function
Facilities containing radioactive material become damaged, and boundary function, leak detection function and shielding functionof radiation are lost.
(2) Loss of monitoring function
Monitoring facilities and instruments fail, and monitoring functions are lost in facilities necessary for measures regarding
decommissioning and contaminated water.
(3) Loss of function in new facilities and existing facilities currently in use
Functions are lost in facilities necessary for conducting decommissioning other than those subject to (1) and (2) above.
② Occurrence of industrial accidents (involving personnel or facilities)(4) Collapse of buildings or architectural structures*, falling or flying of structures
Industrial accidents caused by collapse of buildings or architectural structures, or falling/flying of structures.
(5) Collapse of existing facilities*, falling or flying of structures
Industrial accidents caused by collapse of existing facilities, or falling/flying of structures.
*includes staircases, handrails and corridors that are part of buildings and facilities

Concept of the scope for the long-term maintenance management plan

All on-site facilities and equipment*1
List from the long-term inspection planprior to the earthquake

Handrails, etc.

Pipe/duct, etc.
(near corridors)
Control panel,etc. (nearcorridors)

Existing facilities
currently in use

Pipe/duct, etc.
Main turbine, (containing
stagnant
etc.
water)
Flow meter(unused system),etc.

Exhaust stack, etc.

Reactorinjection pipe
(partial), etc.
Unit 4 CST level
meter etc.

Reactor Building,
etc.

[Existing facility](facilities existing prior to the earthquake)

Barrel, etc.

List from the current long-term
inspection plan*2

Facilities currently in use for decommissioning activities andcontaminated water management
Crane (installed after theearthquake), etc.

Monitoring facility

Level gauge for stagnant waterin buildings, etc.

Supplementary: These
initiatives and concepts havebeen explained anddisclosed at the Commission
on Supervision and
Evaluation of the Specified
Nuclear Facilities in the past.

Architectural structure
Building cover, etc.

[Newly installed facility](facilities installed after the earthquake)*1 Initiated work from approx. 340,000 cases identified subject to facility maintenance*2 Facilities handling contaminated water and facilities monitoring radioactive dust are subject to management as temporary facilities with the exception of those used temporarily as part of construction equipment.

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7<Reference> Priority of Measures for All Facilities and Equipment
 All on-site facilities and equipment were categorized into “mechanical facilities”, “electric facilities”, “other facilities”,“instrumentation facilities” and “architectural structures”; and priorities were set based on the current management status.
Furthermore, priorities for facilities and equipment not in the category of “architectural structures” were set based on theperspective of boundary function

All on-site facilities and equipment
Approx. 225,000 cases*1①

Mechanicalfacilities

Electric
facilities

Facilitypriority 1
Approx.
640 cases

Facilitypriority 2

Other facilities

Approx.
37,000 cases

Facilitypriority 4
Approx.
116,000 cases

Approx. 115,000 cases*1③

Instrumentation(monitoring) facilities
Monitoring
priority 1
Approx.
300 cases

Facilitypriority 3
Approx.
10,000 cases

Approx. 580 cases*2

Architectural
structures
Building
priority 1

Monitoring
priority 2
Approx.
100 cases

Building
priority 2

Approx.
10 cases

Monitoring
priority 3
Approx.
65,000 cases

Facilitypriority 5
Approx.
29,000 cases*Not subject to assessment: approx. 32,000 cases④②

Approx. 340,000 cases

Approx.
60 cases

Building
priority 3
Approx.
30 cases*Not subject to prioritization: approx. 450 cases,
removed: approx. 30 cases*Not subject to assessment: approx. 50,000 cases

Approx. 340,000 cases*1

Boundary function

Boundary priority 1

Boundary priority 2

Boundary priority 3

Approx. 36,000 cases

Approx. 24,000 cases

Approx.
198,000 cases*Not subject to assessment: approx. 82,000 cases©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

*1 Number of equipment or parts*2 Number of buildings

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8<Reference> Specific Measures in the Long-term Maintenance Management Plan
(representative examples: ① mechanical facilities, electric facilities and other facilities)【Equipment】• Units 1-3 spent fuel poolManagement of long-term
inspection plan
Material includedHigh
Medium• Facility priority 2: review of additional measures“necessary”• Boundary priority 3: additional measures“unnecessary【Management status of facilities】

Grade i：High radiation concentration, inventory is above medium level,
and has significant impact on the environment in the event ofa leakGrade ii：Medium radiation concentration and inventory level, andthere is concern for environmental impact in the event of aleakGrade iii： Low radiation concentration and inventory level, andenvironmental impact is small in the event of a leak

Low

【Results of assessment for prioritization】

Radiation concentration【Inventory grade】

Small

MediumInventory

Large

Yes
Liquid radioactive material

Boundary requirements

Yes

Impact on industrial safety

None

Impact on required function

Yes

Leak detector

None

Weir

Yes

Inventory gradeⅱ

Unit 1 Spent Fuel Pool

【 Facility priority 2, details of additional measures 】

Photograph taken August 2, 2019 Leak prevention regarding pool liner•Installed covers on the spent fuel pool to prevent pool from being damaged by falling rubble (Unit 1).
• Monitored pool water quality (once in three months) to prevent leak caused by corrosion of pool liner, and purified poolwater if necessary.
 Response to water leak from pool
• If water level of spent fuel pool lowers due to damage in the pool liner, maintain water level of pool by supplying water
via the emergency water injection facility.

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2-2. Representative Example of Reviews① Addition of new facilities and equipment in FY2020

Facilities related to the Units 1-4 access control points, facilities related to the subdrain iron removal unit,
additionally installed facilities and piping for interior RO, facilities for the additionally installed
miscellaneous solid waste treatment building, etc.

② Review of maintenance strategy

Considering the state of deterioration and records of failures, switched from breakdown maintenance(BDM) to time-based maintenance (TBM) as part of measures to avert risk in long-term use. Examples
include:-Parts of existing multi-nuclide removal facility (existing ALPS) and existing desalination system (existingRO)-Outdoor containers storing rubble including radioactive materials, etc.

③ Equipment under trial operation and addition of temporary facilities

Unit 3 R/B seismometer, corridors near facilities, containers and small cabins for storing equipment, etc.
Regarding temporary equipment in long-term use, a section responsible for the maintenance is to beclarified in the future ,considering details acquired from on-site walkdowns and information from eachgroup, so that a system which allows continuous management can be developed.

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2-3. Example of Initiatives for the Long-term Maintenance Management Plan

(1) Removal of the existing Units 1-4 D/G stack

Deterioration of the stack was confirmed when making the longterm maintenance management plan. A restricted area was set as
an immediate temporary measure.
As a permanent measure, work to remove the stack was planned tobe conducted from August 2021 to March 2022.

(2) Management of containers storing rubble, etc.

Containers located outdoors were not stored in appropriate management conditions.
Therefore, for high priority containers holding radioactive material, visual inspection andchecking contents are being conducted.
In the future, these outdoor containers shall be managed appropriately in the long-term
maintenance management plan, and shall be subject to regular inspection.

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2-4. Measures to Improve Reliability Which Consider Deterioration of Facilities(examples)
In addition to initiatives in the long-term maintenance management plan, consider risks to thesystem (with significant impact during trouble occurrence), and take initiatives for measures toimprove facility reliability.
 Multi-nuclide removal facility (existing ALPS)

ａ．Replacing parts experiencing many defects, updating facilities with risks that have manifested
Supply tank, pressure resistant hose (implementation of steel piping) [FY2021-FY2024]
ｂ．Secure spares for main equipment and their parts (to reduce the duration of shutdowns)
Cross-flow filter (CFF) [continuously procured from 2021 onward] Multi-nuclide removal facility (additionally installed ALPS)
Acquire spares for CFF [continuously procured from 2021 onward] Desalination unit (existing RO)

Newly installed supply line for treated water [planned for FY2022]

 Cesium absorption unit (SARRY)

Updated valve rack [FY2021 – FY2022]

 PCV gas control system

Updated motor for Units 1 and 3 [2023-2024]

 Decontamination unit (AREVA)
Treatement of water retained in system (after disposing waste sludge in D pit) [around 2024]©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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2-5. Challenges in Facilities Management

 Existing facilities: Need to address age degradation and impact by explosion at thetime of the accident
 Newly installed facilities: Need to expand know-how about operation & maintenance,
because they’re jury-rigged or new (without any track record).
 Need to consider quake resistance to continue decommissioning work for a long time Need to consider high radiation dose and effect by radioactivity
Facilities

Challenges

Existing facilities

Effect of ACCIDENT

RPV, PCV,
Reactor building etc.

Aging
Quake resistanceNew facilities

Newly designed

Water injection facilities forreactor, Gas management
system for PCV, Facilities forstagnant water treatment, ALPS
etc.

Aging

©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Quake resistanceHigh dose・radioactivity

Measures

Design/Operation &Maintenance
R&D, Aseismic design tailoredto each equipment,
Disintegration & inspection,
monitoring, Examination of
aging, Remodeling & repair,
Replacement, Removal
e.g.
Robot technology/Design for
quake resistance enhancement/
Dismantlement of Unit 1&2
exhaust stack/Investigation of
R/B /Transportation of HIC

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3. Radiological Control©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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3-1. On-site Dose Reduction
 Removed top soil so that values lower to 5 μSv/ｈ, and conducted ground facing As a result, people can work in general uniforms in 96% of the premises (G zone)
On-site dose rate

On-site zoning

Dose rate (μSv/h）
提供：日本スペースイメージング(株)(C)Digital Globe

提供：日本スペースイメージング(株)(C)DigitalGlobe

Ｒzone©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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Ｙzone

Ｇzone

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3-2．Radiation Protection Gear

R zone(Anorak area)
Full-face mask

Anorak over coveralls

Y zoneG zone(Coverall area)(General clothes area)

Full-face mask or half-face mask*1

Disposable dust proof mask*2

Coveralls

General uniform*1 Work performed inside buildings housing water treatment facilities or buildings near Units 1-4 (excluding the common pool and cover
structure interior on the Unit 4 R/B refueling deck), as well as work involving the handling of contaminated water, and work
accompanying the risk of radioactive material being dispersed requires the use of a full-face mask.
*2 Subject mask is not required for work performed outside the Units 1-4 peripheral protection zone (with the exception of areas insidebuildings of Units 5 and 6), work that does not involve the handling of contaminated facilities or equipment, as well as for light work
which does not accompany the risk of radioactive material being dispersed, and also when moving via vehicle between gear exchange
points or resting areas.

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3-3. Monitoring Concentration of Radioactive Material in the Air●Monitor via dust monitor on the refueling floor (Unit 1: 4 locations, Unit 2: 4 locations, Unit 3: 5 locations)●Monitor via the on-site dust monitor (15 locations)Monitor via site boundary dust monitor (8 locations)●Site boundary monitoring posts (8 locations)©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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3-4. Exposure Dose Management conducted to observe legal limit (50mSv/y, 100mSv/5y)
 Exposure decreased by shielding, decontamination, remote control, time
management and procedure adjustment

Changes in external exposure dose since December 2011
(monthly average dose)

Subcontractors

External exposure dose (average dose) msv

TEPCO employees

December 2011 December 2012

December 2013 December 2014 December 2015 December 2016

*December 2011 (Step II) and later©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

December 2017 December 2018 December 2019 December 2020

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3-5. Introduction of the Remote Monitoring System (RMS) A remote dose monitoring system is utilized to monitor individual exposure for the purpose of reducing
exposure of workers working under high dose environments such as in the reactor buildings, etc. (referto figure below).
 Exposed dose of workers (mSv), air dose rate (mSv/h) and condition of the work area are being
monitored in real-time, and instructions are given remotely via communication devices to reduce theexposure of work supervisors and radiation control personnel.

Low dose area

High dose area
Image
IP camera

Dose rate Exposed dose

Audio
Communication device

Monitor

Dose rate

MonitorSpeaker Microphone

Dosimeter, dose indicator

Worker in
the field

Exposed dose

Overview of the remote monitoring system for individual exposure (remote monitoring system)©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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3-6. Monitoring Using Monitor for Drainage Channel
 Monitor leakage ofcontaminated water using thedrainage channel monitor
 In stages, install monitors
capable of monitoring β rays(from Sr-90) without being
affected by fallout caused by
precipitation (γ ray fromradiation Cs)(currently installed in drainage
channel K and drainage channelof the unloading area)

Units 1-4 intake,open ditch

Units 1-4

Tank
area

：Drainage channel A：Drainage channel of the unloading area

：Drainage channel K：Drainage channel BC：Continuous monitoring unit
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3-7. Sampling Inside and Outside the Harbor Monitor radiation concentration in seawater both inside and outside the harbor【Sampling points for seawater】【Measures to reduce radioactive material in the harbor】

海洋への影響を監視（8箇所）
Monitor
impact on the ocean (8 locations)

シルトフェンス
Silt fence
海側遮水壁
Sea-sideimpermeable wall
海底土被覆
Seabed covered with soil

Seawaterradiation monitor (1 location)
海水放射線モニタ（１箇所）
Monitor distribution of radiation concentration in the
港湾内の放射能濃度の分布を監視（７箇所）
harbor (7 locations)
港湾内への影響の監視（２箇所）
Monitor
impact on the inside of the harbor (2 locations)(Measuressuch as decontamination, enhancement of ground（陸側については、除染、地盤改良、遮水壁などの対策実施）
foundation, installation of impermeable wall conducted on land)

Other(31 locations along the coast [7 in Miyagi Prefecture, 28 in
その他（沿岸31箇所［宮城県7・福島県28・茨城県6］）
Fukushima Prefecture, 6 in Ibaraki Prefecture])

Units 1-4 intake
１~4号機取水口開渠
opening

Unit
6号機6 Unit
5号機5

１号 1Unit
Unit
３
２
4号4
1u
2u号 2 Unit3u号 3 Unit
4u

橋梁
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3-8. Sample Analysis

 Approx. 80,000 samples are analyzed annually.
(approx. 16 times larger than the number prior to the accident.) On-site laboratories are used primarily, and smart glasses are used to improve thereliability of analysis.
 The chemical analysis building (capable of handling samples with low radiation
concentration) has acquired ISO/IEC 17025 qualification regarding the analysis ofcesium 134,137 and tritium.

Image displayed on the inner side of the glass

Chemical manipulation prior to tritium
analysis(chemical analysis building)

Smart glass enables staff to conduct
analysis, while confirming analysis
procedures and data trend from graphs＜Video demonstrating the use of smart glass＞
https://www.tepco.co.jp/library/movie/detail-j.html?catid=107299&video_uuid=cmr78g35©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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4. Waste Management©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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4-1.Waste storage management (1)Temporary storage(outdoors)

Generation
On-site locations

Rubble (combustibles)
Approx. 60,000m3*1,2

Main work: on-site weeding

Felled trees

Approx. 130,000m3ळ1,2

Projected
Amount in thenext decade orso:Approx. 780,000
m3*2

Protective clothing

Subject to volume
reduction

Combustible
material
Noncombustible
material

Approx. 50,000m3ळ1,2

Volume reduction

Incineration
facility

Volumereduction
processing
facility(Coveralls：approx. 700,000/year)

Rubble etc.

(Metal, concrete, etc.)
Approx. 190,000m3*1,2
Key work：Rubble remova at Unit 1
Flange tank disassembly

Earth and sandApprox. 40,000ｍ３ळ1,2

Storage
Solid waste
storagefacility
Buildings 1-9(in use)Approx.
70,000m3*2
Building 10(under review)
Approx.
80,000m3*2

Not subject tovolume reduction

Building 11(under review)
Approx.
110,000m3*2

Subject to reuse

Outdoorstorage until
being
recycled
Approx.
200,000m3(waste with highdose, etc.)

Key work：Creation of sitepremisesळ1：Volume generated as of March 2020
ळ2：Rounded off numbers under 10,000m3©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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4-1.Waste storage management (2) The volume of waste planned to be stored inside buildings by the end of FY2030 isapprox. 260,000 m3.
 The storage capacity of existing solid storage facilities is approx. 70,000 m3, so
expanding the capacity by 190,000 m3 is being considered.
 Volume of solid waste stored in the solid waste storage facility buildings 10 and 11
shall be distributed in accordance with the dose level of the subject waste.
10,000 m3
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 （年度）
<Low dose solid waste storage facility>25

低線量：１mSv/h以下
Low
dose: 1 mSv/h or lower

Current storage
現在の保管容量capacity

Approx. 80,000 m3
Approx.
stored in building 10
80,000 m3
for solid waste
storage

20
15
10
5

25

Storage capacity of existingsolid storage facilities
既設固体庫の保管容量(approx. 24,000m 3)
3

Storage
capacity
保管容量
exceeded
超過（約2.4万m ）105Storage capacity of existingsolid storage facilities
既設固体庫の保管容量(approx. 42,0003 ） m 3)
（約4.2万m

Approx. 70,000 m3

Current storage
現在の保管容量capacity

高線量：１mSv/h超High
dose: over 1 mSv/h

20
15

保管容量不足分Lackof storage capacity
3 ） 3（約15.2万m(approx. 152,000m)

Storage保管容量
capacity
exceeded超過

Lackof storage capacity
保管容量不足分
3(approx. 39,000
3 m )（約3.9万m ）Approx.
40,000 m3

2019年度保管管理計画より引用

Transition of固体庫の保管量推移（線量別）
volume stored in solid storage facilities (by dose)©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

無断転載・複製禁止 東京電力ホールディングス株式会社<High dose solid waste
storage facility>(Can also be used to store lowdose solid waste)

Approx. 110,000 m3
stored in building 11 forsolid waste storage25

4-2. Storage of Rubble etc. (current status)
There are various outdoor temporary storage areas for rubble etc. littered on the site premises of 1F (approx. 50 locations)⇒The outdoor temporary storage area shall be eliminated in FY2028 ळ, and waste material shall be stored indoors(at the solid waste storage facility).
ळExcludes area for materials to be reused

Waste sludge storage facilities

Solid waste storage facilities
1 and 2
Area GArea AA

Area X

Area P
Area LArea A

Area E Unit 6 Unit 5

Area D
Area CArea B

Miscellaneous solid
waste incineration
facilities

Area F

Area Q

Area H

Spent Cs adsorption stack,temporary storage facilities

Unit 1Unit 2Unit 3Unit 4

Area W

Area T

Area V

Solid waste storage facilities
3 through 8

Area M

Cesium adsorption stack, temporary storage facilities

Solid waste storage
facilities 9

Area OArea N

Area U

Spent Cs adsorption stack,temporary storage facilities

Treatment facilities
Rubble storage area
Storage area for felled trees
Storage area for used protective clothing
Spent Cs adsorption vessel, temporary storage facilities
Waste sludge storage facilities, concentrated liquid waste
storage tank (completed)

Area J

Concentrated liquid waste
storage tank (completed)

Rubble etc.
Secondary wastefrom water
treatment process©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Provided by: Japan Space Imaging Corporation, (C) Digital Globe

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4-2. Storage of Rubble etc. (in the future) Layout of premises in FY2028 when the outdoor temporary storage areasळExcludes area for materials to be reusedfor rubble etc. is eliminatedSolid waste storage facilities
1 and 2
Area AA

Area P

Spent Cs absorption stack,temporary storage facility

Unit 1Unit 2Unit 3Unit 4

Unit 6 Unit 5
Miscellaneous solid waste
incineration facilities

Area C

Solid waste storage
facilities 3 through 8

Large waste
storage facilities
Additionally installed solid
waste storage facilities

Volume reduction
facilities

Pre-treatment facilities for
waste prior to incineration

Solid waste storage
facilities 9Spent Cs adsorption vessel
temporary storage facility

Additionally installed miscellaneous
solid waste incineration facilities

Concentrated liquid waste
storage tank (completed)

Treatment facilities

Storage containers, storage facilities(rubble etc. and secondary waste from water treatment process)

Storage area for materials to be reused

Spent Cs adsorption vessel, temporary storage facilities
Waste sludge storage facilities, concentrated liquid
waste storage tank (completed)-Secondary waste fromwater treatment process©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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Provided by: Japan Space Imaging Corporation, (C) Digital Globe27

4-3. Waste Management: Volume Reduction Processing Facilities

 Overview of facilities and aseismic performance
Overview offacility

Facility for cutting metal rubble and crushing concrete rubble. Target volume reduction rate isapprox. 50%.

Processing
capacity

Metal：Approx. 60 m3/day
Concrete：Approx. 40 m3/day

Building
structure

Steel frame construction (areas with shielding function: reinforced concrete), built withadequate shielding capabilities and structural strength

Aseismicclass

Class C

Initiation ofoperation

FY2022 (currently under review)

Temporarystorage area

Metal

Separatematerials

Flow of processing

Volume reduction processing facility
Metalsundergocutting
Concrete iscrushedProcessed metal is
enclosed in containers
Container
Processed concrete is
enclosed in containers

Storage
Container

Concrete©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Solid waste
storage facility

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4-4. Waste Management:
Additionally Installed Miscellaneous Solid Waste Incineration Facilities

 Overview of facilities and aseismic performance
Overview offacilities

Facilities mainly for incinerating felled trees and combustible rubble (kiln stoker
type incinerator). Target volume reduction rate is below 10%.

Processing
capacity

95 t/day (operated 24 hours a day)Building
structure

Reinforced concrete, built with adequate shielding function and structural
strength

Aseismic classClass B (main equipment such as incinerators, building)/
Class C (components other than above)

Initiation ofoperation

FY2021
Additionally Installed Miscellaneous Solid Waste Incineration Facilities
Schematic Diagram
Additionally installed solid waste incineration building

Exhaust stack

Secondaryincinerator

Bag filter

Waste storage pit

Exterior view of building©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Kiln, stoker
fired furnacePre-filter

Exhaust gas
blowerExhaust cooler
Ash extraction unit

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Two stage HEPA filter

29

4-5. Waste Management: Large Waste Storage Facilities
 Overview of facilities and aseismic performance
Overview offacilities

Facilities for storing large and heavy waste such as secondary waste generated
from water treatment during the operation of contaminated water treatment
facilities.

Processing
capacity

Building 1： Approx. 4,000 m2(adsorption vessel 744 units：SARRY 360 units, KURION 384 units)
Building 2：approx. 8,000 m2(Equivalent to approx. 1,200 adsorption vessels) (to be reviewed in the future)

Building
structure

Steel frame construction, precast slab built with adequate shielding function andstructural strength

Aseismic classClass B

Initiation ofoperation

FY2021 (currently under review)
Secondary waste from water treatment currently temporarily stored

Storage at the large waste storage facilities©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Adsorption vesselof No. 2 cesium
adsorption unit
(SARRY)

Adsorption vessel ofcesium adsorption unit
(KURION)

無断転載・複製禁止 東京電力ホールディングス株式会社

High performancecontainer for multinuclide removal
facility (ALPS)30

4-6. Waste Management: Effort to Reduce Waste Generation
 The volume of generated waste will be reduced to the extent possible andtransition to indoor storage will be conducted.
 In parallel, restriction on bringing in unnecessary materials, appropriate segregationand decontamination to be conducted to reduce waste generation
 Reduce environmental load through reuse of supply and metals etc.
Restriction
on bringing inmaterials

Segregation/Decontami-nation

Effective use of resources
Reduce environmental load
©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Reduce Waste
Generation

Volumereduction

Storage

Reuse

Scaffold, Tool, Heavy machinery

Reuse

Metal, Concrete

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5. Measures Against Natural Disasters©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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32

5-1. Policy for Measures against Earthquakes and Tsunami
 Measures and assessments critical for ensuring safety are being implemented
in stages in view of their feasibility, etc.
*Data for tsunami protection measures have been revised in view of highest water levels observed in
vicinity of former tide station.

TsunamiEarthquakes

Measures against Outer-rise Tsunami (T.P.4.1m)
Completed: construction of seawall

Urgent Measures
After Disaster

Responses toFurther New
Findings

Protection
against Most
ExtremeDisaster Ever

Protection
against Disaster
Exceeding
Most Extreme
Disaster Ever

Measures against Design basis seismic groundmotion (600Gal)
Completed- Structural soundness confirmed for eachbuilding- Earthquake-resistant design of spent fuelremoval equipment- Dismantling of Units 1, 2 exhaust stack

Measures against Kuril Trench Tsunami (T.P.10.3m)
Completed: construction of seawall

Measures against Japan Trench Tsunami (T.P.11.8m)
Under consideration: construction of seawall

Measures against 3.11 Tsunami (T.P.15.1m)
In progress: Sealing openings of each building
Completed: Relocation and fixing of Mega Float

Measures against maximum reference seismic
ground motion (900Gal)
Completed: Check for structural soundness ofeach building

Measures against maximum reference tsunami (T.P.22.6m)
In progress: Treatment and relocation to the hill of stagnant water in buildings
Under consideration: Relocation to the hill of sludges from decontamination device

Measures Using Portable Equipment
Completed: Relocation of fire trucks, power source vehicle, heavy machinery, concrete pumping vehicle, etc. to the hill

* Design basis seismic ground motion: seismic ground motion used as reference for an earthquake-resistant design taking into consideration knowledge and data before the Great East Japan Earthquake and the Regulatory Guide for Reviewing Seismic Design of Nuclear Power
Reactor Facilities (seismic ground motion of the same magnitude as that observed on the site during the Great East Japan Earthquake)* Maximum reference seismic ground motion: seismic ground motion assumed under the most extreme conditions for a power station taking into consideration knowledge and data after the Great East Japan Earthquake and the new regulatory standards* Maximum reference tsunami: tsunami assumed under the most extreme conditions for a power station taking into consideration knowledge and data after the Great East Japan Earthquake and the new regulatory standards* Outer-rise tsunami: tsunami likely to be caused by a normal fault earthquake occurring at the outer-rise part (uplift area at the outer side of an ocean trench) after an interplate earthquake* Kuril Trench Tsunami: tsunami to be caused by an earthquake occurring along the Kuril Trench* Japan Trench Tsunami: tsunami assumed reflecting the report of the “Cabinet Office’s Committee for Modeling a Megaquake along Japan Trench and Kuril Trench”©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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33

5-2. Seawall Against Tsunamis from the Japan Trench (1)highest high water level T.P. (m) Height of the seawall has been set by “tsunami data analysis” reflecting thelatest horizontal alignment of seawall which takes into account the workers’
traffic line of ongoing and planned decommissioning projectJapan Trench Tsunami

Unit 1 to 4
planned height of Japan
Trench Tsunami Seawall

Outer-Rise Tsunami- Required height of seawall derived fromtsunami analysis (highest water level) by assuming vertical infinite wall atplanned location for seawall,

south side of Unit 4

Kuril Trench Tsunami Seawall Outer-Rise Tsunami Seawall

Simulation of Japan
Trench Tsunami
Unit 1

Unit 2

Unit 3

Unit 4process mainbuilding
unit: mOuter-Rise Tsunami

Kuril Trench Tsunami

Japan Trench
Tsunami※ height and other details
may change during thefuture construction work

Unit 1 to 4

South side of Unit 4

Analysis results－

T.P.9.7 to 12.7 (plan)
T.P.8.6 to 13.5 (present assessment)

wall height－

T.P.11.0 to 12.8 (plan)

Analysis results

T.P.10.3－

wall height

T.P.11.0－

Analysis results (present
assessment)

T.P.10.3 to 13.4

T.P.12.1 to 14.9

Planned wall height*

T.P. about 13.t to 15

T.P. about 15 to 16©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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34

5-2. Seawall Against Tsunamis from the Japan Trench (2)Key

T.P. 2.5 m wall

Direction ofview

Seawall
Access route
Reinforced
slope

T.P. 8.5 m wall
Unit 1

Unit 2

Unit 3

Unit 4

Units 1-4
side

PMB

Unit 4
southside

#2R/B
#2T/B
T.P.8.5m wall

Reinforced
slope

#1R/B
#1T/B

T.P.2.5m盤

N

Mega-float

Access route
Seawall©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

Access route

無断転載・複製禁止 東京電力ホールディングス株式会社*only representativebuildings have been
included35

5-3 Sealing of Building Openings
 Purpose: As measures against 3.11 Tsunami for main buildings in Unit 1 to 4, sealing of building openings is under way. It aims toprevent leakage of stagnant water in buildings into sea due to backwash. It also aims to avoid tsunami waves inflow to the extent
possible so that the increase in stagnant water in the buildings can be curbed.
 Progress: “Sealing” or “inflow prevention” for openings of main buildings in Unit 1 to 4 are under way
As of end of May, 2021, 116 out of 127 completed as scheduled
 Areas 1, 2
⇒ end of FY2018(completed) Area 3, 2∙3R/B (external floor)⇒ end of FY2019 (completed) Area 4, 1~3R/B (door)⇒ Nov. , 2020 (completed) :buildings with stagnant water Area 5, 1~4Rw/B, etc.
⇒ To be completed by the end of FY2021(in progress): buildings without stagnant water

Before measures

(FY)

R/B
mountain-side

stagnant water

After measures: tsunami intrusion routes(openings on walls andfloors)sea-side
T/B

Tsunami water flows in from external wall openings then fromfirst floor openings and reaches basement floor to mix withstagnant water.

: openings for sealing

R/B
Area 4
Area 3

×

Area 4

T/B

Building

1

Unit 1, 2 T/B,
HTI, PMB, common
pool

40/40

2

Unit 3 T/B

27/27

3

Unit 2, 3 R/B(external floor, etc.)

20/20

4

Unit 1 to 3 R/B(doors)

16/16

5Unit 1 to 4 Rw/B
Unit 4 R/B,T/B

13/24

Area 1, 2

×1

Openings to be sealed to produce watertight area

© Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. Prohibition of use, duplication, and disclosure of confidential information for other purposes

2018

2019

2020

2021
Current

to be completed at end of FY2021

1

4 5
5 4
stagnant waterCompleted/
Planned No.

Area

5

2
5 4

5 5
3

36

5-3. Progress in Sealing of Building Openings

 Increase in the number of areas where
measures have been completed

 Status of measures

Category(compared to the previous count as of January
25, 2021)

①
②
③
④
⑤

 Category ③ 2R/B external floor

Number ofcompletedareas

Increase
Plannedin thenumberofnumber ofcomplete
areas
Previous Current d areas

Building
1･2T/B, HTI,
PMB, common pool
3T/B

40

40

0

27

27

0

20

20

0

1-3R/B (door)
1-4Rw/B
4R/B,4T/B

16

16

0

24

10

13

+3

Total

127

113

116

+3

2･3R/B(External floor, etc.)

①

②

⑤

④ ⑤⑤ ④

⑤④

⑤⑤

①

③

©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

2R-8

Completed

Before measures aretaken

2020.1After measures are
taken

Method: Closure using concrete Category ③ 4T/B external floor
4T-10

Completed

Before measures are
taken

After measures are
taken

Method : Closure using water proof panel
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2020.337

5-4. Construction work of new drainage channel D
Outlet of drainage
channel A[Construction Outline]

The drainage channel D, which can be the most effective against rainstorm risk,
will be developed to resolve rainstorm risk before the typhoon season in 2022.
As shown in the figure below, the total length (red line) is about 800 m(propulsion tunnel Φ2200), and the water is drained into the port in the sea areain front of the landing site.
Based on the results of the internal water inundation analysis, connection spacehave been added to the area where rainwater flows into the northeastern part ofUnit 1.
(Internal water inundation analysis will be conducted in the future with the final
drainage channel shape)

Drainage channel A(after replacement)

Unit 6Landing site

Excavation section 14m□2000×2000
Vertical shaft on
downstream side

Connection
space C

Drainage channel of landing
site

Unit 1

Unit 5

Unit 2

Unit 3

Unit 4
Drainagechannel K

Newly constructeddrainage channel

Okuma Street

Formerdrainage
Former drainage channel A
channel A

Downstream
propulsion section of
about 692 m
Φ2,200

New drainage channel
D

Small-diameter
propulsion workOutlet of drainage channel DΦ600

Connection
space B
Drainage channel B

Drainage channel
A
Jinbazawa River

Ｎ

Drainage channel
D

Drainagechannel C“Provided by Japan Space Imaging Corporation, ©DigitalGlobe. Taken on Dec. 25, 2014.”©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

無断転載・複製禁止 東京電力ホールディングス株式会社

Fig. 1 Overview of on-site drainage channels

Vertical shaft for
both sides

Vertical shaft on upstream
side(Connected to existingwater channel)

4

Upstream
propulsion
section of about
126 m

Φ2,20038

6. Summary©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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39

6. Summary

Reduce risk in the Fukushima Daiichi Nuclear Power Station by procceding with thedecommissioning project, and conduct management in accordance with the progress of workand environmental changes.
 Risk management
 Systematically reduce risk unique to the Fukushima Daiichi Nuclear Power Station in accordancewith RM and LTP.
 Plant maintenance Identify age degradation and maintaining integrity of newly installed facilities (with little or no prior
operating experience) Confirm and secure integrity of existing facilities (affected by the accident)
 Radiological control
 Exposure reduction through decontamination, shielding and use of remote operation technologies.
 Environmental impact assessment through monitoring of area within and outside of site premises,
and applying results to the decommissioning project Waste management
 Stable storage (secondary waste from water treatment, etc.), storage after volume reduction(concrete, metals, combustibles) Controlling waste generation (controlling reception of off-site materials, recycling, etc.)
 Measures against natural disasters
 Clarifying aseismic requirements for new facilities (currently under review) Measures for facilities against tsunami and heavy rain (seawall, drainage channel, etc.)©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

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40