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All Rights Reserved ©2014 Tokyo Electric Power Company, Inc.
Inside JapanInside Japan’’s Nuclear Meltdowns Nuclear Meltdown~~A TEPCO Nuclear EngineerA TEPCO Nuclear Engineer’’s Perspective~s Perspective~
Program on U.S.Program on U.S.--Japan RelationsJapan RelationsHarvard UniversityHarvard University
Cambridge, MassachusettsCambridge, MassachusettsSeptember 9September 9thth, 2014, 2014
Kenji TateiwaKenji TateiwaManager, Nuclear Power ProgramsManager, Nuclear Power Programs
Tokyo Electric Power Company, Washington OfficeTokyo Electric Power Company, Washington Officetateiwa.kenji@tepco.co.jptateiwa.kenji@tepco.co.jp
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’90~’96: Kyoto UniversityBS/MS in Nuclear Engineering
’96~: TEPCO’96~’00: Fukushima Daini NPS’00~’02: Nuclear Engineering Dept., Tokyo-H/Q (severe accident analysis)’02~’04: MBA, Stanford Graduate School of Business’04~’05: Nuclear Engineering Dept.’05~’11: International Affairs Dept.Mar.~Sept.’11: Fukushima Response Int’l Team, Tokyo-H/Q Sept. ’11~: Washington DC Office
My Background
TEPCO class of ’96in Naraha-town, Fukushima(Jan. 2000)
Pursued “Nuclear Renaissance” in Texas(June 2010)
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’90~’96: Kyoto UniversityBS/MS in Nuclear Engineering
’96~: TEPCO’96~’00: Fukushima Daini NPS’00~’02: Nuclear Engineering Dept., Tokyo-H/Q (severe accident analysis)’02~’04: MBA, Stanford Graduate School of Business’04~’05: Nuclear Engineering Dept.’05~’11: International Affairs Dept.Mar.~Sept.’11: Fukushima Response Int’l Team, Tokyo-H/Q Sept. ’11~: Washington DC Office
My Background (cont’d)
Great East Japan Earthquake(March 11, 2011)
http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=77331
Then, everything changed…
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My Post-Accident Activities
IAEA Preliminary Mission(4/6/2011@Fukushima Daiichi NPS)
IAEA: International Atomic Energy Agency
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“Nothing has been more important in my career than supporting TEPCO”
INPO: Institute of Nuclear Power OperationsNRC: Nuclear Regulatory Commission
My Post-Accident Activities (cont’d)
U.S. INPO-Led Industry Support Team(8/19/2011@Fukushima Daini)
Reinforcing US-Japan Tiesw/ NRC Chuck Casto
(4/7/13@Austin)
Reinforcing US-Japan Tiesw/ Ambassador John Roos
(6/15/11@Tokyo)
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The Great East Japan Earthquake (GEJE)
http://archive.shinsai.yahoo.co.jp/
http://archive.shinsai.yahoo.co.jp/
http://archive.shinsai.yahoo.co.jp/Cruise Ship Stranded
Houses Swept Away
Largest earthquake (M9.0) and tsunami (M9.1) in recorded history of Japan
20+ m tsunami run-up in coast line spanning 200 km
560 km2 flooded (10x Manhattan)
19,000 dead/missing
http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=77331
Epicenter
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Operation Tomodachi (“Friends”) by U.S. Armed Forces
http://www.defense.gov/news/newsarticle.aspx?id=63439
http://www.defense.gov/home/features/2011/0311_japan/ http://www.defense.gov/home/features/2011/0311_japan/
http://www.defense.gov/home/features/2011/0311_japan/
U.S. Armed Forces’ disaster relief efforts were highly appreciated by the Japanese people
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Impact of GEJE to TEPCO Facilities
Epicenter
52 GW
31 GW
Beforeearthquake
Shortly afterearthquake
Lost 40% of power supply
capacity
Shutdown: Nuclear power: 7 units Thermal power: 12 units Hydro power: 25 units Substations: 8
Power outage: 4 million households Rolling blackout for 10 days
Massive interruption of infrastructure: Public transportation Telecommunication Food/water supply
Restored >99% of power by day 4
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TEPCO’s Nuclear Power Stations (17 BWR Units)
(source) JAIF
U-1U-2U-3U-4
Fukushima Daini (2F)
U-6U-5U-1U-2U-3U-4
Fukushima Daiichi (1F)Kashiwazaki-Kariwa (KK)
U-1U-2U-3U-4U-5,6,7
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TEPCO’s Emergency Response Centers (ERC)
Video conference among multiple
ERCs played instrumental role
Tokyo H/Q Fukushima Daiichi
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Tsunami at Fukushima Daiichi (1F)
Estimated Tsunami Height:13.1 m = 43 ft. (4-Story Bldg.)
4x historical-high and 2x design-basis
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Plant Status After Tsunami
All reactors shutdown automatically as designed after earthquake
Tsunami led to Station Black Out and loss of core cooling capability
Core melt and metal-water reaction led to H2 explosionin reactor buildings
Stabilization by sea water injection via fire trucks
Schematic of 1F Unit 1
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Accident Response at 1F: In the Field
Roads blocked by tsunami debris
Roads damaged by earthquake
Continual aftershocks, tsunami alerts, open manholes, etc. exacerbated the situation
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Supervised operation wearing full-face mask
Checked instrumentation in near-complete darkness
Brought in heavy batteries to restore instrumentations
Lack of: instrumentation, communication means, lighting, food, water, sleep, ...
Increase in: radiation level, fatigue, fear, despair, ...Yet, operators stayed behind to carry
through their duties
Accident Response at 1F: In the Main Control RoomPhotos taken as
“mementos”
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72AO
ボンベ
210MO ラプチャーディスク
排気筒
1AO
ボンベ
閉
閉
83AO
閉
閉90AO
0.549MPabsで破壊
RPV
D/W
RPVRPV
D/W
IA
IA
D/W最高使用圧力0.528MPabs
ベント実施圧力0.954MPabs
電磁弁
電磁弁
213AO
Remote operation unavailable due to SBO.
MO
AO
AO
AO
AO
MO
Exhaust stack
Rupture disc
Six men formed 3 “last-resort teams” to manually open 2 valves in highly-radioactive areaCore damage already progressing by this time
(3/12 9:04-9:30)
Venting required to
avoid catastrophic
failure
Accident Response at 1F: Unit 1 Containment Venting
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inoperable
standby
Shallow Draft Quay
Sea
Valve Pit Valve Pit Valve Pit Valve Pit
Fire Cistern
Fire Cistern
Fire Cistern
Fire CisternFire
Cistern
Fire trucks played critical role in injecting water into reactorsFire brigade operated fire trucks
amidst high radiation/successive explosions
Status as of 3/14/2011
Accident Response at 1F: Water Injection by Fire Trucks
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http://www.mod.go.jp/gsdf/crf/pa/saigaihaken/touhokutihoujisin/kakogazou/kako-jv-touhoku/march/23.3.30_2/jv-touhoku.html
Fire Truck ofJapan Self Defense Force
Fire Truck ofTokyo Fire Department
http://www.tfd.metro.tokyo.jp/hp-kouhouka/kts/kts_03/kts04.html
Accident Response at 1F: Water Injection by Fire Trucks (cont’d)
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3/16-19
3/20
3/14
3/12
42 3642 1531
3/15
3/13
3/11
2F1FDate
3/14 17:00
3/14 1:24RHR
3/14 7:13RHR
3/14 15:42RHR
3/14 18:00
3/15 7:15
3/12 12:15
3/20 14:30
3/19 22:14RHR
3/12 8:13D/G-6B
3/22 10:35P/C-4D
3/22 10:36P/C-4D
3/20 15:46P/C-2C
3/20 15:46P/C-2C
3/19 5:00RHR
3/20 14:30
Station Blackout
Loss of Ultimate Heat Sink
Cold Shutdown
3/12 15:36 Unit 1 Explosion
3/15 6:00-6:10 Unit 4 Explosion
3/14 11:01 Unit 3 Explosion
3/11 15:27 1st Tsunami, 15:35 2nd Tsunami 3/11 15:22~ Tsunamis
Water Injection: NOHeat Removal: NO
Water Injection: YESHeat Removal: NO
Water Injection: YESHeat Removal: YES
Overview of the 10-Unit Simultaneous Accidents
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0
20
40
60
80
100
120
140
160
180
200
3/11
3/12
3/13
3/14
3/15
3/16
3/17
3/18
3/19
3/20
3/21
3/22
3/23
3/24
3/25
0
50
100
150
200
250
300
350
400
450
500
DailyCumulative
Hundreds of Aftershocks Greater than M 5.0D
aily
Num
ber o
f Afte
rsho
cks
Cum
ulat
ive
Num
ber o
f Afte
rsho
cks
On March 11th alone179 times > M 5.038 times > M6.03 times > M7.0
cf. Earthquake in Virginia on Aug. 23, 2011: M 5.8
(Source) Japan Meteorological Agency
http://www.youtube.com/watch?v=eKp5cA2sM28Visualization of earthquakes in 2011
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“In an attempt to check the status of Unit 4 D/G, I was trapped inside the security gate compartment. Soon the tsunami came andI was minutes away from being drowned, when my colleague smash opened the window and saved my life.”
“In total darkness, I could hear the unearthly sound of SRV dumping steam into the torus. I stepped on the torus to open the S/C spray valve, and my rubber boot melted.”
“Unit 3 could explode anytime soon, but it was my turn to go to the main control room. I called my dad and asked him to take good care of my wife and kids should I die.”
Voices from the Field (First Responders at 1F)
Unit 1 Main Control Room
Torus Room
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Voices from the Field (First Responders at 1F) (cont’d)
“The Man Who SawThe Brink of Death”“Book reveals human drama in Fukushima No. 1 crisis”
The Japan Times 12/11/2012http://www.japantimes.co.jp/news/2012/12/11/national/book-
reveals-human-drama-in-fukushima-no-1-crisis/
“At that time, I was conjuring up faces of fellow colleagues who would die with me.”(Masao Yoshida, Site Superintendent)
“I was determined to stay behind to my death; however I was resolved to send my men back home alive.”(Ikuo Izawa, Shift Manager)
“Let me go and vent the containment.I know where the valve is and I can run fast. Let me protect the unit that I love.”(Kazuhiro Yoshida, Deputy Shift Manager)
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TEPCO Internal Investigation Committee Final Report
Issued on June 20, 2012http://www.tepco.co.jp/en/press/corp-com/release/2012/1205638_1870.html
“Tangible”Countermeasures•Flood Protection•High-pressure Injection System•Depressurization System•Low-pressure Injection System•Heat Removal/Cooling System•Power Supply for Instrumentation•Post-Core Damage Mitigation•Common Items•Mid-to-Long Term Items
“Intangible”Countermeasures
• Operational Measures in Relation to Tangible Modifications
• Emergency Preparedness• Info. Dissemination and Sharing• Roles and Responsibilities• Information Disclosure• Transportation of Resources• Access Control• Radiological Protection• Plant Status Recognition• Suggestions to the Government
Major Lessons Learned:Recognize large uncertainty in external eventsPrepare for the unexpected
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Current Status of Fukushima Daiichi (1F)
Unit 4
Unit 3
Unit 2Unit 1
Unit 2Unit 1
Unit 3
Live Camera View(as of 8/29/2014)
http://www.tepco.co.jp/en/nu/f1-np/camera/index2-e.htmlhttp://www.tepco.co.jp/en/nu/f1-np/camera/index-e.html
View 1
View 2
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Progress Made at 1F
All reactors and spent fuel pools stably cooledRobots utilized extensively to investigate and
decontaminate inside reactor buildings77% of fuel bundles transferred from Unit 4 to
common fuel pool (as of Sept. 2014)
Unit 1 Unit 2 Unit 3 Unit 4
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Tackling Water Issues at 1F
(c) GeoEye/Japan Space Imaging
Groundw
ater Flow
Groundwater BypassSub-drain
Frozen-Soil Wall
Sea-Side Impermeable
Wall
Water Glass
Emergency and fundamental measures taken to:
Prevent groundwater from being contaminated
Prevent contaminated groundwater from flowing into sea
Reduce groundwater inflow into buildings
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Decommissioning Roadmap for 1F
Phase-1 Phase-2 Phase-3
Begin removal of fuels from spent fuel pools
Cold ShutdownCondition Achieved(Dec., 2011)
Within2 years
Within10 years
30 to40 years
Begin retrieval of fuel debris
Complete decommissioning
Global collaboration vitally important to tackle this unprecedented undertaking
Common pool
CraneFuel Handling Machine
Unit 4: Nov. 2013
Stop Leakage Flood PCV andRemove Fuel Debris
Today
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TEPCO’s Post-Accident Activities in the U.S.
Professional Organizations, Think Tanks, NPOs, Media
AcademiaGlobal Organizations
Nuclear Industry Gov’t Agencies
Committed to sharing lessons learned; making nuclear power plants safer; carrying out decommissioning safely
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References[Japan] Tokyo Electric Power Company (TEPCO)http://www.tepco.co.jp/en/nu/fukushima-np/index-e.htmlhttp://www.tepco.co.jp/en/decommision/index-e.html
Nuclear Reform Monitoring Committee of TEPCO
http://www.nrmc.jp/en/index-e.html
Ministry of Economy, Trade and Industry (METI)
http://www.meti.go.jp/english/earthquake/
Nuclear Regulation Authority (NRA)http://www.nsr.go.jp/english/
Japan Atomic Industrial Forum (JAIF)http://www.jaif.or.jp/english/
Japan Nuclear Safety Institute (JANSI)http://www.genanshin.jp/english/index.html
[USA]Institute of Nuclear Power Operations (INPO)http://www.nei.org/Master-Document-Folder/Backgrounders/Reports-And-Studies/Lessons-Learned-from-the-Nuclear-Accident-at-the-F
Electric Power Research Institute (EPRI)http://www.epri.com/Our-Work/Pages/Nuclear.aspx
Nuclear Energy Institute (NEI)http://safetyfirst.nei.org/japan/
National Academy of Science—Fukushima Lessons Learned Committeehttp://www8.nationalacademies.org/cp/projectview.aspx?key=49465http://www.nap.edu/catalog.php?record_id=18294
[International]International Atomic Energy Agency (IAEA)http://www.iaea.org/
World Association of Nuclear Operators (WANO)
http://www.wano.info/United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)
http://www.unscear.org/unscear/en/publications/2013_1.html
World Health Organization (WHO)http://www.who.int/mediacentre/news/releases/2013/fukushima_report_20130228/en/
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