lessons of fukushima-daiichi npp's accidents for ...2005/08/02 · fukushima daiichi fukushima...

2012 INTERNATIONAL ISOE ALARA SYMPOSIUM Prof. Narabayashi, Hokkaido Univ. 1

Dr. Tadashi NARABAYASHI Nuclear and Environmental Systems

Hokkaido University

January 9, 2012 (Hyatt Regency Pier)

Lessons of FukushimaLessons of Fukushima--DaiichiDaiichiNPP'sNPP's Accidents for AchievementAccidents for Achievementof the 1st Class Safety in the Worldof the 1st Class Safety in the World

2012 INTERNATIONAL ISOE ALARA SYMPOSIUM2012 INTERNATIONAL ISOE ALARA SYMPOSIUMFukushima Severe Accident Dose Management &Fukushima Severe Accident Dose Management &

Global Lessons Learned in Occupational Dose ReductionGlobal Lessons Learned in Occupational Dose Reduction

Optimization of Nuclear Safety RegulationOptimization of Nuclear Safety RegulationJSME Power and Energy System DivisionJSME Power and Energy System Division


TsuTsunnaammii Flooding Area in each NPPFlooding Area in each NPPFukushima Daiichi Fukushima Daini

Onagawa Tohkai Daini

Flood Flood

FloodFlood

Rushed

Rushed

Rushed


TsuTsunnaammii Flooding Area in each NPPFlooding Area in each NPPFukushima Daiichi

Fukushima Daini

Tsunami Height#1~#4

#5, #6

Grand Level

#1~#6

#5,#6 Grand Level

#2~#4 No Flooding

#1 Flooding through hatches and air intake for EDG

Flooding through hatches and air intake for EDG

Large DoorHatch

M/C, P/C

R/B

R/B

T/B

Air intakefor EDG

Hatch

M/C,P/C

Hatch

R/BDoor

Tsunami HeightO.P.+7m

Dike

Dike

SeaWaterPump

Basement

M/C,P/C

EDG

EDG


SBO in Fukushima Daiichi NPPsSBO in Fukushima Daiichi NPPs#1 #2 #3 #4 #5 #6

DGA:NGB:NG

(T/B B1)

A:NG(B1)

B:OK(FP/B 1F)

A:NGB:NG

(T/B B1)

A:NG(T/B B1)

B:OK(FP/B 1F)

A:OK->NGB:OK->NG

(T/B B1)Water

Cooling

A:OK->NG(R/B B1)

Water CoolingB:OK

(DG/B 1F)

Metal-Crad

Swich

NG(T/B B1)

NG(T/B B1)

NG(T/B B1)

NG(T/B B1)

NG(T/B B1)

Barely(R/B B2F)

PowerCenter

NG(T/B B1)

Barely(T/B B1)

NG(T/B B1)

Barely(T/B 1F)

Barely(T/B 2F)

Barely(R/B B2F)

DCButtery

NG(C/B B1)

NG(C/B B1)

OK(T/B BM1)

NG(C/B B1)

OK(T/B BM1)

OK(T/B BM1)

ECCS

RCIC

HPCI:NG

IC:OK(FC)

NG

RCIC:OK

HPCI:OK

RCIC:OK

(No Fuels in RPV)

HPCS:OK(R/B B1)

fujii-y

テキストボックス

資料41-1-2

fujii-y

ノート注釈

fujii-y : Unmarked

fujii-y

タイプライターテキスト


SBO in Fukushima Daiichi SBO in Fukushima Daiichi NPPsNPPsTsunami

DC P/C AC P/C EDG RHRS

AC Power Lost

Battery Lost

DC Power Lost

EDG Trip

Loss of UHS

SolenoidValveLost

AOValve

Failure

MOValve

Failure

MotorFailure

AirLost

Flood

ProcessMeasurement

Failure

IC,RCIC,HPCI ControlFailure

MS-SRVActuator Failure

HVAC,SGTSFailure

PCVVENT

Faliure

Water Makeup Pump Failure

Heat Removal, ECCS Failure

Engine PumpFailure


ICs in unit #1 were tripped by FCICs in unit #1 were tripped by FC� Loss of battery power for main control room caused the fail-close action to

MO isolation valves to stop the IC. It was a fail-dangerous system.� If the IC continue to operate, the accident would be terminated soon.

IC ControlValve

Fire Pool

Water Tank

SteamBlowout

IsolationCondenser

� RCIC steam turbine also stopped by loss of battery power in Unit #2 and #3.

� S/P temperature and pressure were so high that AM water injection took a lot of times.RPV

S/P


CV Pressure Trend in unit #1CV Pressure Trend in unit #1� After loss of ECCS and IC core cooling, CV pressure increased.� Water level drifted by vaporizing water in reference leg.� Radiation level increased at T/B.� Hydrogen explosion occurred after S/C wet venting.

Water level drifted


Pressure and Water Level in #1Pressure and Water Level in #1 RPVRPV� Analysis results show the RPV depressurization started before RPV bottom

failure. It might be caused through melted TIP tubes in the core.� Water level measurement was drifted by the loss of water in a reference leg

by high-temperature superheated core.

RP

V P

ress

ure

(MP

a)

RPV Bottom Failure

RP

V W

ater

Lev

el (m

)

TAF Level (3hr)

BAF Level (3hr)

Water Injectionl (15hr)

Water Level datadrifted more than 4m

IC cooling


CV Pressure Trend in unit #2CV Pressure Trend in unit #2� After loss of RCIC water injection, DW pressure increased.� Water level was decreased after RCIC tripped.� RPV pressure was too high to water injection by Fire pump.� Explosion sound occurred near S/C.

RPV Pressure was too high to water injection

Water level in RPV

RP

V (M

Pa)

?

DW Pressure


Failure of prompt water injection in #2Failure of prompt water injection in #2� Failure of prompt water injection after RCIC stopped in unit #2 caused the

core damage and H2 generation started.� High-pressure discharge pump driven by diesel engine should be used.

RP

V P

ress

ure

(MP

a)

H2

prod

uctio

n (k

g)

Unit #2 RPV Pressure Trend

RCIC Started RCIC StoppedSRV Opened

RPV Bottom Failure

Melt Core relocation to Low plenum

Core Damaged

Lost of Battery


Radiation level increased after CV raptureRadiation level increased after CV rapture

3/11 3/12 3/13 3/14 3/15 3/16 3/17 3/18Nikkei Science, July 2011

H2 detonation were occurred after vent operation (#1, #3, #4)Radiation level increased soon after #2 CV rapture

1F Monitoring Trend

14000

12000

10000

Rad

iatio

n Le

vel (�S

v/h) #1 Vent started

#1 Detonation

#3 1st Vent

#3 Detonation

#3 2nd Vent

#4 Detonation

#1 Vent #3 1st Vent #3 2nd Vent #2 2nd Vent


Fukushima Daiichi Fukushima Daiichi Sevier AccidentSevier Accidentss

Unit #1

Unit #4

Unit #3

Unit #2

3/123/11 3/13 3/14 3/15

CoreMelt

CoreMelt

ICTrip V

ent

CoreMelt

HPCI, RCIC(Steam turbine driven) V

ent

H2Leak

RCIC(Steam turbine driven) V

ent


H2 Leak Path from CVH2 Leak Path from CV�CV top flange and hatches might be leak pass


Cause of HCause of H22 Detonation in #4 R/BDetonation in #4 R/B�#4 was in outage. No fuels in the core�Hydrogen from #3 flowed into #4 via SGTS


##44's SGTS Filters were contaminated's SGTS Filters were contaminatedFukushima Daiichi Unit #4

Aug. 25, 2011TEPCO

�Filters in SGTS showed that H2 and FP supplied from #3flowed into #4 R/B

SGTS valves and contamination check results

SGTSFilters

OpenOpenOpen

Open

Open

OpenClose

CloseS/P

Vent Line

Stuck

Open

Open

R/B

Fan

Fan

Open


#3's SGTS Filters were contaminated#3's SGTS Filters were contaminatedFukushima Daiichi Unit #3

Dec. 26, 2011TEPCO

Open

Open

Open

Open

Open

Open

Open

Open

Close

Close

Close

Close

Close

SGTS valves and contamination check results

Vent Line

R/B

S/P

Vent Line

Stuck

Stuck

GravityDumper

Fan

Fanc

SGTSFilters


Vent was a cause Vent was a cause ofof suicide bombing ?suicide bombing ?Fail-Open valve in SGTS supplied H2 and FP into R/B

SGTS Filter

SGTS Filter

PCV Open

OpenOpen

Open

Open

Top FlangeLeak


Hydrogen Detonation and CV RaptureHydrogen Detonation and CV Rapture

#1#2#3#4

CV RaptureDetonation

Air Photo Service Co.

Detonation Detonation


Zeolite

Condenser

WaterRecoveryTank5MW

Decay�Heat� MWOn�the�decrease

Clean�up

CoolingTower

(2)ContaminatedWater Shieldalong Seashore

� We proposed water recycle system for core cooling on March 28

Sea

FeedWaterTank

(1) Water Recycle for Core Cooling, Shield, Remove debris

Boilingvolume�reduction

Salt

FP�recovery�Tank

H2 Venting

SaltPlant

Water Recycle System for Core CoolingWater Recycle System for Core Cooling

RadiationShieldConcreteSteel Panel

Spent Fuel Pooleolight


TMI-2:Large Egg in core Chernobyl: Elephant's Leg

Large Egg and Elephant's LegLarge Egg and Elephant's Leg

Egg


Comparison between Chernobyl and FukushimaComparison between Chernobyl and Fukushima

UkraineKiev

30km Zone Size

Minsk

Belarus

Fukushima

Russia

1/501Total

1/131Cs,I

Fuku-shima

Cher-nobyl

Released FP

~0.011001

Fuku-shima

Cher-nobyl

TMI-2

Core thermal output


Reactor

SpentFuel Pool

Pool

Mist Separator

Lessons of Chernobyl NPP Accidents promoted the installation of FilteredVent System to protect radioactive materials exhaust.French, German, Switzerland, Finland, Norway

DF 1/100-1/1000I2 CsI etc.


(1)Preventing C/V rapture(2)Preventing Radioactive material exhaust

Fukushima Daiichi NPP#1 C/V 7bar + Vent + H2 Explosion ~1day#2 C/V 7bar + No Vent + C/V rapture ~3.5days#3 C/V 6bar + Vent + H2 Explosion ~3days

Prevent over-pressure C/V rapture + Exhaust of RI and H2� Filtered Containment Venting System (FCVS)

Prevent over-temperature C/V rapture + H2 leakage� Special Emergency Heat Removal System (SEHR)

JSME visit Leibstadt NPP, Swiss, on Nov.11,2011

Objectives of Filtered Vent SystemObjectives of Filtered Vent System

Feed and Bleed under Long SBO & LUHSBackfitted on 1992 for (mitigation of Sever Accident)


VisitVisit ChoozChooz NPP, EDF FranceNPP, EDF France

Filtered Vent


VisitVisit LeibstadtLeibstadt NPP, KKL, SwitzerlandNPP, KKL, Switzerland

Filtered Vent


FCVS (FCVSFCVS::FilteredFiltered Containment Venting SystemContainment Venting System

DF> 1000 Aerosol> 100 I2

Fuel rod

Steam

NaOH

MOVNormalClose

MOVNormalOpen

Rapture Disk (~3bar)

Stuck

Solubility pH10Solubility pH7 ~50

Backfitted on 1992 for (mitigation of Sever Accident)

�Vent valve will be open by manual shaft when SBO


Suppression Pool

Fuel rod

Steam

�After the TMI-2 accidents, KKL back-fitted the DiD3 (additional C/V cooling)and DiD4 (mitigation of Sever Accident).

DiD: Defense in Depth

HeatExchanger

UndergroundDwells

D/G D/G

Two D/G for SEHR

SEHR ( )SEHR:SpecialSEHR:Special Emergency Heat Removal SystemEmergency Heat Removal System


Special Power Generator on HeightSpecial Power Generator on Height� 4000kVA mobile gas-turbine generator at 31m parking Hepco

Gas-turbine generator will be installed at 25m Chubu Electric)

TP+85m

TP+25m

Gas-Turbine Generetor4000kVA, 3.2MW3.3kV-6.6KVStart within 40sec

R/B


Countermeasure 2. Heat Removal SystemCountermeasure 2. Heat Removal SystemDecay�heat: %�1000MWe:�30MW

CoolingTower

PCV

S/P

PLR Pump

Feed Water Pump

RPV

Sea Water Pump

Main Condenser

Turbine Generator

PowerTransmissionMain

Transformer

Steam

Water

Sea

RCIC


Heat Sink by Sea Water NetworkHeat Sink by Sea Water NetworkChubu ElectricHamaoka NPP


Power Source in German 2010(Total 6.2x1011kWh, Tentative)Sustainable Energy Statics

Sustainable Energy in German: Only Sustainable Energy in German: Only 1.9%1.9% SolarSolar

Nuclear

Coal

SustainableEnergy

Oil

Others

WindBiomass

Solar

Hydraulic Wastes

Breakdown of Sustainable Energy

CapacityFactor

Nuclear: 20.3 TWSolar: 17.0 TW

Broun Coal


The death toll in France, Killer heat Total 50,000 died in 2003 and 2006

18

Elbe River, Dresden, German, July 2006

�Global Warming brings heat waves�CO2 may be much danger than radioactivities

Killer Heat Wave in EuropeKiller Heat Wave in Europe


Fossil Energy Estimation in FutureFossil Energy Estimation in FutureHuman being will exhaust all Human being will exhaust all fossilefossile fuelsfuels

2570

DemandDemand

4242

6060

133133

100100

Present

Coal

Natural Gas

OilOil Natural Gas Coal Uranium

Utilization of Plutonium

in FBR

Equ

ival

ent O

il E

nerg

y (1

08t)

Year

Y

Y

Y

Y

2570Y


Nuclear Education for Saudi ArabiaNuclear Education for Saudi Arabia

President Saeki,Hokkaido Univ.

�King Abdulaziz University asked to Hokkaido University for Nuclear Education

Oil in Saudi Arabia would be empty within 60 years if they wouldn't use nuclear


Progress in Kuala Lumpur, MalaysiaProgress in Kuala Lumpur, Malaysia


Nuclear Education in MalaysiaNuclear Education in Malaysia

Tsunami-Proof NPP


ConclusionConclusion�Fukushima Daiichi NPP accident would be terminated,

if sufficient examination lead to install countermeasuresfor tsunami, such as water proof door, mobile power, etc.

�In Europe, it had already installed the Heat RemovalSystem and Filtered Venting System from the lessonsof TMI and Chernobyl Accidents.

�Vent line should be independent from SGTS/HVAC line.�From the Lessons of Fukushima-Daiichi Accidents,

we should achieve the 1st class Nuclear safety in theworld NPPs.

�Solar and sustainable enegy will not sufficient to replacethe nuclear energy. Both the energy should be used infuture.

�Nuclear education is very important to maintain the Nuclearsafety technology and safety culture in the world.

lessons of fukushima-daiichi npp's accidents for ...2005/08/02 · fukushima daiichi fukushima...

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