JAEA Report on Progress of Decontamination Efforts after Fukushima Daiichi Nuclear Disaster

8/2/2019 JAEA Report on Progress of Decontamination Efforts after Fukushima Daiichi Nuclear Disaster

1/24

JAEAActivities

onDecontamination

toward EnvironmentalRestorationofFukushima

ShinichiNAKAYAMA

JAPAN ATOMIC ENERGY AGENCY


2/24

1.AssessmentsofRadiological

ContaminationSituation

monitoringandmapping

2.DemonstrationofDecontamination

schoolyardandswimmingpool

decontaminationpilotprojects

3.R&D on EnvironmentalRestoration

monitoringsystemusingAUH

computersimulationfordose

reduction.

4.CommunicationActivitiesforReliable

Information

JAEAActivitiesforEnvironmentRestoration

1


3/24

Further investigation of radionuclide distribution

2Cs137depositiondistribution

map

Detailedmeasurementsandmappingofground

surface depositiondistributionofradionuclides

Widearearadiationdoseratedistribution

measurementsand

mapping

using

monitoring

vehicles

Theresultsprovidesthesourcetermfor

predictivemodelsoffutureradioactivespread.

Radiationdoseratedistributionmaps

MeasurementusingsurveyvehiclesDoseratemeasurementateachmeshelements

1. ASSESSMENTSOFRADIOLOGICALCONTAMINATIONSITUATION

Surfacesurvey

2


4/24

(JAEA NSTC)(JAEA NSTC)

1

3

1.ASSESSMENTSOFRADIOLOGICALCONTAMINATION SITUATION

AircraftradiationmonitoringaroundFukushima


5/24

(JAEA NSTC)(JAEA NSTC)

1

4

1.ASSESSMENTSOFRADIOLOGICALCONTAMINATION SITUATION

AircraftradiationmonitoringaroundFukushima


6/24

2.DEMONSTRATIONofDECONTAMINATION

Schoolandkindergartenplayground

5

Kindergarten

Junior highschool

First aid: Decrease the playground

dose rate and store the removed soil

in-situ.

JAEA team; performed precise dose rate

measurements,

identified the cesium intrusion

depth, and

estimated the safety ofunderground trench storage of

the removed soil. .

Contaminated surface soil of 5-cm thick was removed

and put into trenches in a corner of the schoolyard. Dose rate significantly reduced by factors of 10 to 20;

School: (avg.) 2.5 0.15 Sv/h at 1 mH

Kindergarten : (avg.) 2.8 0.22 Sv/h at 50 cmH

The results underlies the government, MEXT, announcement to apply theremove-andtrench work as a tentative dose reduction to Fukushima schools.


7/24

6


Schoolswimmingpool

Notafewoutdoorswimmingpools

stillholdCsrichwater.

Theflocculationmethodwas

appliedfor

purification

of

water.

Radioactivesludgewascollected

andstoredatatemporarystorage

space.

Auserfriendlyhandbook;Guide

forDecontaminatingSchool

SwimmingPools waspublished.

Fosteredatrustful

relationship

withschoolofficials,municipality

andresidentsthroughdialogue

anddecontaminationwork.

NationalFukushima

Univ. JuniorHigh

School

Before Over 200 Bq/L - Cs

After N.D.

Kizuna(:

bond)

team

and

JAEA

staffforschoolpooldecontamination


8/24

Purpose

Toacquiretechnicaldataandknowledge,andprovideintegratedexpertiseforthecominglargescaledecontaminationproject.

Checkthe

availability

and

efficacy

of

proven

and

new

techniques

Investigatecost,workperiod,workforce,wastegenerated,andworkers

radiationexposure

Establishwastemanagementincludingvolumereductionofwastesand

treatmentof

the

secondary

waste

Workerssafetyandradiationprotection

Establishoptimalradiationmonitoring

Recordthepubliccommunication

DecontaminationPilot

Projects

at

Model

Sites;

Project1:AreasincludingSpecific SpotsrecommendedforEvacuation(2

sites)

Project2:AreasincludingDeliberateEvacuationArea&Restricted

Area(19

sites

in

11

municipalities)


DemonstrationPilotProjects

7


9/24


DecontaminationPilotProject 1

City

of

Date

and

City

of

Minami

Soma

ModelareainDatecity

ModelareainMinamiSomacity

8


10/24


11/24

10


DecontaminationPilotProjects:Building


12/24

11


DecontaminationPilotProject:Concrete,Asphalt

highpressurewater

roadcleaner

blasting

Iceblasting

Ironshot

blasting

surfacestripping


13/24

12


DecontaminationPilotProject:Farmland

plow

fixation

topsoilremoval

turfstripping


14/24

13


DecontaminationPilotProject:Trees,Forest

weeding

removalofleafmold

clipping waterhorsing

clipping clipping

waterremovalofleafmoldcuring


15/24

14


Volumereductionofradioactivewaste

watertreatment

flocculationprecipitation

column

adsoption

chipping pruningandsticks


16/24


Temporarystorageforradioactivewaste:moundtype

15

Drainpipe

Impermeable layer

or liner sheet

Protective layer

Supplemental

layer for water

collection

Impermeable layer

or liner sheet

Tank for checking of

radioactivity concentration

of seeping water

Embankment or sandbags

for shielding

Flexible container bags

Gas discharge


17/24


Temporarystorageforradioactivewaste

16

Drainpipe

Impermeable layer

or liner sheet

Protective layer

Supplemental

layer for water

collection



of seeping water Embankment or sandbags

for shielding

Impermeable layer

or liner sheet


Rock

Sandbags

Embankment for

shielding

Protective layer

Supplemental layer for

water collection

Impermeable layer

or liner sheet

Impermeable layer

or liner sheet



of seeping water

Rock

Dam

Impermeable layer

or liner sheet

Protective layer

Supplemental

layer for water

collection


for shielding



of seeping water

Impermeable layer

or liner sheet



Drainpipe

Impermeable layer

or liner sheet

Protective layer

Supplemental

layer for water

collection



of seeping water


for shielding

Impermeable layer

or liner sheet

Gas discharge


18/24

3.R&DonENVIRONMENTALRESTORATION

AutonomousUnmannedHelicopter(AUH)

Monitoring

System

17

Airdoserate (1mhigh)canbemeasuredfromanaltitudeof30m


19/24


MeasurementofradiationdistributionbyPlastic

Scintillation

Fibers

(PSFs)

18

PSFs data

Survey Meter

0

2

4

6

8

10

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 2 4 6 8 10 12

uSv/h)

PSF(cp

s)

Position (m)

No. 3

Two-dimensional measurement

Rolling and contoured surface, due to the

bendable nature.

Underwater surface such as brook bed andpond settlement, due to the waterproofness.

19PSFsbundled


20/24


21/24

20


Surfacecleaningbyhighpressurewater

decre

ase

water pressure, MPa

decrease, %

countsperminute

before after

after

waterpurification


22/24

JAEAtechnicalstaffaredispatchedtoFukushimaprefectureschools(fromkindergartenstojuniorhighschools)upontheirrequest

Afterbriefings

on

radiation,

JAEA

staff

memberstalkfacetofacewithparentsandteachers,answeringtheirquestionsonradiationanditshealtheffects.

132sessionshavebeenheldsinceJuly,and

atotal

of

142

sessions

are

scheduled

as

of

December4.

Briefingmaterials

4.COMMUNICATIONSandINSTRUCTIONS

Questionandanswersessiononradiationandhealth

21


23/24

About

100

persons

are

measured

per

day About7,300havebeenmeasuredbylastNovember,

andatotalof 8,000personsarescheduledbythe

endofDecember,2011.

15minuteto1hourQ&Aper person is welcomed

aftereach

measurement

EnergyspectrummeasuredMeasurementbyWholeBodyCounter

JAEAhasmeasuresinternalexposureofpeoplewithinthe

restrictedareaanddeliberateevacuationareausingthe

WholeBodyCounter(WBC)inTokaiLaboratory


WBCmeasurementforFukushimapref.residents

22


24/24

JAEAdispatchesitsexpertstoofficial

trainingcourseofdecontamination

works plannedby

Fukushima

pref.,

as

supervisorstoensuringsafetyand

enhancingtheskillsofworkersand

operatorsengagingindecontamination

works.Participantscompletedarecertifiedby

thegovernorof

Fukushima.

Completioncertificate

Curriculumoftrainingsession

3,000workers

and

operators(equivalentto

halfofconstructorsin

Fukushima)willbe

anticipated

by

the

end

ofFY2011.


Dispatchofsupervisorstotrainingsessions

on

Certified

Decontamination

Workers/Operators

23

Day1 Day2

Opening 5.Safety

management

during

decontamination

works

1.Overviewofthe

accident

2.Fundamental

knowledgeon

radiation

6.Radiation

effectsonhuman

health

3.Radiationsafety

management

7.Demonstration

andpractice

4.

Decontamination

method

8.Exam.

Closing

Documents

JAEA Report on Progress of Decontamination Efforts after Fukushima Daiichi Nuclear Disaster