Status of Fukushima Daiichi NPS
November 2013

Hideki Masui
Safety Research Manager
Tokyo Electric Power Company

Contents
1.Status of Fukushima Daiichi NPS
2.Current Topics- Inventory Control (Water Management)- Fuel Removal from unit 4 SFP- Inner PCV Investigation

3.Future Activity toward Decommissioning
4. Concluding Remarks

11. Status of Fukushima Daiichi NPS

2

Fukushima Daiichi (1F) Unit 1~4
Covering Structure
SFP

Blow-out Panel(now closed)

Reactor
Building

Crawler Crane

Fuel Removal Covergantry

PCV
RPV

Injection

Injection

Injection

FuelDebris
Vent
ContaminatedWaterUnit 1

Unit 2Unit 3

Unit 43

Roadmap for Recovery and Decommissioning
Roadmap for immediate recovery
2011.4/17
2011.3/11
Road Map▼▼

2011.7/19
STEP 1▼

Steadydecrease ofradiation
release2011.12/16
STEP 2▼Significant decrease ofradiation release
Stabilized RPV
temperature

Roadmap for DecommissioningNow▼
2 years

2011.12/19
Roadmap
STEP 1,2

Stabilizationof Reactor

Phase 1

Start of fuel removalfrom storage pool

10 years

30-40 years

Phase 2Phase 3

Start of fueldebris removal

Completion ofDecommissioning4

Monitoring Data of Fukushima Daiichi
3.7→ 2.7Data as of:Jul. 17, 2012 (Red)Nov.11, 2013 (Blue)(μSv/h)6.8→ 4.8

Unit 5,6
8.1→ 5.4
7.7→ 4.8

Unit 1-4
7.7→ 5.1
221→ 145
7→ 520→ 15
8.6→ 2.9
6.5→ 3.1
5

Estimated Radioactive Release Rate
(108Bq/h)

Cs-134/137 Release Rate from Unit1,2 and 3

12108

1x107Bq/h is equivalent of
0.02mSv/y at site boundary

642Jul
Aug
Se
pO
ct
Nov
Dec
JanFebM
arApr
MayJunJul
Aug
SepO
ct
Nov
DecJanFebM
arAprMayJunJulAugSe
pO
ct0

2011

2012

2013
6

RPV Bottom Temperature
RPV bottom temperature maintains under 100℃

Unit 2
Unit 3

Unit 1

2011

2012

2013
7

PCV Atmosphere Temperature
PCV Atmosphere temperature maintains under 100℃

Unit 1

2011

2012

2013
8

2. Current Topics- Inventory Control (Water Management)- Fuel Removal from unit 4 SFP- Inner PCV Investigation

9

Inventory Control(Contaminated Water Management)

10Current Scheme for Contaminated Water Management
Recirculation
Recirculation Cooling
Cooling SystemSystem
R/B
Cesium removal

T/B
400m3/day(74,600m3)

Ground water

Reactor water
Water injection
injectiontank

Desalination- Reverse osmosis- Evaporator

Water
injection pump(m3)

Inventory

Capacity

Nov.2013

388,744

417,900

Mar.2016-800,000

Data as of Nov.19, 2013

Storage tanks
319,815m3

Secondary Waste
Storage

Multi Nuclide Removal
System (ALPS)

Storage tanks
30,202m3
11

Identification of Radiation Release
Location of Observation well

2.8

2.6

Ground Water Level

2.4

No.3

2.2

No.1
No.2

2.0

1.8

No.1

No.2

No.3

地下水位（海側No.1）

1.6

地下水位（海側No.2）
地下水位（海側No.3）

水位（OP)［m］

1.4

1.2小名浜潮位

Sea Level

1.0

0.8

0.6(1)Water from observation well was
contaminated

0.4

0.20.0(2)Ground water level wassynchronized with sea level-0.2-0.4-0.6
5月6日

5月7日

5月8日

5月9日

5月10日

5月11日

5月12日

5月13日

5月14日

5月15日

5月16日

測定日時

Radioactivity was released into sea
12Drainage of Water from Underground Trench
Accumulated contaminated water will be removed from undergroundtrench１号機タービン建屋
Unit 1 T/B

２号機タービン建屋
Unit 2 T/B

Unit 3 T/B
３号機タービン建屋
About 5,000 m3 of contaminatedwater are accumulated
立坑Ｄ

立坑Ａ1/300

Seawater Intake

立坑Ｂ

Contaminated water is cleaned up
via mobile Cs removal unit (ongoing)

立坑Ｃ

Penetration between T/B andtrench will be sealed byfreezing. Then water will be：トレンチdrained (expected tostart in（配管等を収納したトンネル）
Apr.2014)○：タービン建屋との取り合い部

H23.4.2
漏えい確認箇所

Pit has been closed with mortal after
removal of contaminated water (Done)13

Chemical Injection, Pump-up, Covering
Reducing groundwater flow through contaminated area
Reducing permeability by chemical injection
Pump-up of groundwater
Covering the surface
Chemical Injection

AA
Pump-up from well

1uR/B

2uR/B 3uR/B 4uR/B

Covering with asphalt

Gravel埋立汚染水

Chemical Injection

Permeable Layer
透水層揚水井Impermeable
難透水層 Layer

A-A Crosssection
Chemical Injection（As of Nov. 7, 2013）(water glass)14

Groundwater Bypass
12 wells have been dug to pump up ground water before being
contaminated.
Pumped water are to be released into the sea after radiation check
Already completed and tested. Waiting clearance.

1 2 3 45

7 8

Aline

（C）GeoEye/日本スペースイメージング

910

Bline

GroundwaterDirection

6C line1112：Bypass well：Piping：Temporary Storage Tank
：Observation well：Sub drain well
15

Comprehensive Measures
1. Seaside Impermeable Wall to block water leakage
2. Frozen Wall to block water in-leakage into building
3. Recovery of Existing Well to reduce ground water level

Seaside Impermeable Wall

Frozen wall
Unit 1

Unit 2

Unit 3

Unit 4

Recovery of Existing Well
16

Seaside Wall / Frozen Wall
1. Seaside Impermeable Wall
Construction started in May 2012 and is to complete in Sep. 2014
2. Frozen Wall
Frozen wall will be installed to block water in-leakage
Expected to start operation in 2015
Seaside Wall
＜Image＞＜Actual work＞

Frozen Wall
＜Procedure of Installation＞
Drilling

WallWall

Emplacement of Tube
Circulation of coolant (Development of wall)
Coolant

Existing
Shoreline

Combined
Steel pipe
18 – 27mTube

Frozen wall

Frozen wall17

3-11 Recovery of Existing Well
3. Recovery of Existing Well
Reactor and turbine buildings are surrounded by wells and pumps (called“sub-drain system) to suppress floating power. Those wells are inoperable
due to contamination. Recovery of those existing well can minimize waterin-leak into the building. Recovery is expected to be done in 2014
PumpupBypass well

Permeable Layer
R/B
Groundwater level

PumpupT/B

Pumpup

Impermeable Layer
Permeable Layer

Existing Well
Impermeable Layer

PumpupSeasideWall

Existing Well

Reducing Groundwater Level

18

Leakage from Storage Tank
On Aug.19, water puddle was found around storage tank. Tank

level was found to be reduced by 3m (equivalent of 300m33).
Since drainage valve in the dyke was open, some portion ofwater was leaked outside dyke.
This event was rated to be INES level 3.
Sea

Unit 5-6

Puddle ofContaminated WaterUnit 1- 4
Dyke and drain valve

Trace of leakage

19

Investigation of Leak Cause

Tank has been
disassembled and various
tests have been conducted

Bubble test identified leakage point
0°

Bubble was drawn

270°
90°

180°

20

Investigation of Leak Cause

Sealing Material

Rust
RustFlange

Deformed sealing materialcaused leakage.
Bottom Plate

Bottom Plate

Disassembled Flange21

Emergency Measures
1. Collection of residual water. Recovery of contaminated soil. Inspection of
all flange-type tank.
2. Enhanced patrol. (twice →4 times a day, 10 →60 people)
3. Closure of drain valve
4. Enhanced monitoring along gutter
5. Water level measurement by thermograph
Patrolling with survey meter

Water level measurement by thermograph
Water
液面
surfaceWater
液面
surface

測定結果（昼間）

タンク外観測定結果（夜間）

タンク外観

Water
液面
surfaceWater
液面
surface22Further Measures
1. Installation of level meter for all flange tank
2. Introduction centralized monitoring system
3. Installation of additional weld tank
4. Replacement of flange-tank
監視室
Monitoring
Room

Flange Tank

水位計LevelMeter

現場制御盤（5,6号エリア）

Existing
既設Optical光伝送
Transmission

現場制御盤（Gエリア）

タンクTank入出力盤

・・・

WaterControl
水処理制御室RoomField
現場水位計
LevelMeterタンク
TankNew
新設

・・・

MCR of unit 5,65,6号機中央制御室

現場制御盤（Hエリア）
入出力盤

LANCentralized Monitoring System

・・・

水位データ
集約・伝送

Weld Tank

タンク
Tank
水位計タンク
Tank
水位計

入出力盤

23

Fuel Removal from Unit 4 SFP

24

Spent Fuel Pool Cooling
Air cooled SFP cooling system is installed at unit 1-4
Temperature of SFP has been maintained safely.

原子炉建屋
Reactor Building
屋外
OutsideSkimmer Surge
Tank

スキマサージタンク

Spent FuelPool
使用済燃料プール

Data on Nov.26
Unit 1: 17.5 ℃
Unit 2: 15.9 ℃Unit 3: 15.2 ℃
Unit 4: 23.6 ℃

エアフィン
Air-fincooler
クーラSurge
サージtank
タンク

Secondaryline
二次系

1901-30

FPC pump

FPC系ポンプ

Heat Exchanger
ＦＰＣ系熱交換器

Primaryline
一次系

pump

二次系ポンプV-31-5B： 既設ライン

Existing Line ： 一次系既設ライン
Primary Line ： 二次系仮設ライン
Secondary Line

System diagram of Unit 125

Reinforcement of SPF at unit 4<コンクリート打設前>
Step 1 Steel Support
SFP

鋼製
支柱

Seismic safety analysis,taking account of walldamage, confirmed integrityof R/B at unit 4<コンクリート打設後>Step 2 Concrete Wall
SFP

鋼製支柱

To further improve seismicsafety, upgrade work was
conducted at SFP.

ｺﾝｸﾘｰﾄ壁

26

Water Level Measurement at SFP (unit4)
Measurement result has confirmed SFP is not tilted
Measurement Point
Spent Fuel Pool

③Measurement Date

④ ⑦Equipment storage pool

約11m

①

May 18,2012

Aug 21,
2012

Nov 20,2012

Feb 2,
2013

May.21
2013

Aug.6
2013

①492

462

463

465

467

465

②

492

462

464

464

465

465

③

492

461

463

463

464

465

④

492

461

463

463

465

466

⑧②
Reactor well

Reactorwell⑥

5th floor⑤ 12m10m

Measurement Date1）not tilted
height height2）tilted
height height

SFPMay 18,
2012

Aug 21,
2012

Nov 20,2012

Feb 2,
2013

May.21
2013

Aug.6
2013

⑤461

453

443

444

439

448

⑥

461

453

444

443

439

446

⑦

461

452

442

443

439

446

⑧

461

452

443

443

438

446

27

Debris Removal from unit 4
July 2011

July 2012

Fuel handle

28

Condition of Spent Fuel Pool (Unit 4)（May 2011）（March 2012）(November 2013）

Installation of clean-up system
made water more clear
Debris have been removed.

29

Fuel Removal Cover (Unit ４)
The cover for fuel removal has
been installed in order to improve
work environment and to prevent
radioactive materials fromscattering and releasing during
the work.
Start of fuel removal at Unit 4
started on Nov.18, 2013.
Cover for fuel removal
FuelHandling
FacilityReactor Building

Cover for FuelRemoval

Working area

Crane
Fuel Handling
MachineSpent Fuel Pool
Fuel
Spent Fuel Storage Rack

Cask for onsite
Carry out

Onsite Transportation
原子炉建屋Common pool
30

Fuel Removal Cover (Unit ４)

Fuel Removal Cover

Overhead Crane

Fuel handling machine

Handling of mock-up fuel31

31

Unit 4 Fuel Removal

Transportation Cask

Landing on water

Fuel loading

Fuel loading32

Unit 4 Fuel Removal

Moving Cask

Loading on vehicle

Fuel unloading

Fuel emplacement in rack33

Inner PCV Investigation

34

Result of Inner PCV Investigation (Unit2)
Penetration

Above Water Surface

ＰＣＶ

42.8℃

1m

43.0℃

1m

43.5℃

1m

PCV Inner Wall

Scaffolding

Thermocouple

Inside Water

Water Surface

60cm
48.5-50.0℃
35

S/C Investigation by Robot (unit 2, Mar.2013)
No significant damages were found in venting pipes
Venting Pipe

S/C
Catwalk

Sectional View
Floor View

S/C
Small Robots
Walking Robotwith Four Legs

Pipe Sleeve
Bellows CoverSand Cushion Drain Line

Imaging on investigation of venting pipe by using 3D-CAD
36

Investigation of unit1 S/C by Remote-controlled Boat

Venting Pipe

Suppression Chamber (S/C)
Unit 1 Reactor Building

Investigation was conducted on 13, 14 Nov. 2103

Remote-controlled Boat
37

Investigation Result (1)Leakage has been identified around
one of 8 vent piping.

Vent Piping
Vent Piping

S/C Side Wall
S/C Side Wall

S/C Side Wall

Water Surface

S/C Side Wall

Water Surface
38

Investigation Result (2)Damages were found at sand cushion drain (not PCV boundary)Sand Cushion Drain

Rupture of ring header
Damage of drain piping

39

3. Future Activity toward Decommissioning40

Fuel Debris Removal(1)Deconitaminationof Reactor Building

Decontamination will beconducted to improveaccessibility(2)Inspection of lower
PCVLower PCV will be inspected
to identify leak point

41

Fuel Debris Removal(3)Stop leakage at lower
PCV
Lower PCV and R/B will berepaired. Water will be takenfrom PCV.

Water
taken fromPCV(4)Water filling of PCV

Water will be filled in PCV.
Small circulation loop will beconducted.

SmallCirculation
Loop42

Fuel Debris Removal(5)Inspection of PCV
internals/in-coreinspection/sampling
Inspection and sampling will
be conducted to grasp
characteristics of fuel debris(6)Repair of upper PCVUpper PCV will repaired toallow further water filling43

Fuel Debris Removal(7)PCV flooding/In-core Inspection/Sampling(8)Fuel Debris Removal

PCV will be flooded and fueldebris in RPV will be sampled

Fuel debris will be taken andplaced into storage container.

44

Decommissioning and Waste Management

Plan to complete the reactor facilities decommissioningin Units 1 to 4 within 30 to 40 years after the completion ofStep 2.
Once fuel debris are removed, existing decommissioning
technology may be applicable.
Still, R&D program is needed to develop post-accident
waste treatment method.
45

Concluding Remarks
We have recently started fuel removal out of unit 4SFP, which is an essential step toward
decommissioning.
We are making utmost efforts to control contaminatedwater accumulated on site.
Decommissioning of Fukushima Daiichi is challenging
and long –term project, involving unprecedented R&Dprograms
With the support of government and global partners,
we are committed to carry out this challenging task.
46