Waste management issues arising from the Fukushima accident

22-May -2012

Kunihiro Nakai, JGC Corporation

What happened in Fukushima ?

22-May-2012 1

2011 off the Pacific coast of Tohoku Earthquake

At 14:46 on March 11, 2011, a 9.0-magnitude (M) earthquake occurred. This was the largest of earthquakes in the history of earthquake observation in Japan.

22-May-2012 2

http://icanps.go.jp/eng/interim-report.html

Overview of Damage Caused by the Earthquake and Tsunami

Following the Tohoku District - off the Pacific Ocean Earthquake, a tsunami was observed along the coast in wide areas from Hokkaido to Okinawa.

The total size of the areas flooded by tsunami waves has amounted to 561 km2.

15,840 persons were announced dead and 3,547 persons have been announced missing.

1,009,074 buildings and houses were damaged. Due to these tsunami attacks, the seaside area and

major building areas in the premises of the Fukushima Dai-ichi NPS were almost entirely flooded.

22-May-2012 3 http://icanps.go.jp/eng/interim-report.html

Overview of Damage at the Fukushima Dai-ichi NPS

The cooling capability was impaired because many power supply systems and related facilities at the plant were rendered inoperable due to damage caused by the earthquake or flooding caused by the tsunami.

The containment capability was also impaired and there took place the release of radioactive materials to the external environment.

The details of damage have hardly been confirmed by direct observation because the radiation dose level is still high in the R/Bs and surrounding areas and highly radioactive contaminated water still remains inside the R/Bs.

22-May-2012 4

http://icanps.go.jp/eng/interim-report.html

Flooded Area of the Fukushima Dai-ichi NPS

22-May-2012 5

http://icanps.go.jp/eng/interim-report.html

No.3 and No.4 R/Bs in April 2011

22-May-2012 6

Circulating Water Cooling System and Water Processing Facilities

22-May-2012 7 http://www.tepco.co.jp/en/nu/fukushima-np/review/images/review1_06.gif

Decontamination Instruments

22-May-2012 8 http://www.tepco.co.jp/tepconews/pressroom/110311/indexold-j.html

Radionuclides release from the reactor and

Generation of radioactive wastes

In the site Terrestrial environment was mainly

contaminated by the airborne release and deposition Marine environment

22-May-2012 9

Major Radionuclide in Nuclear Fuel

10

1E+05

1E+06

1E+07

1E+08

1E+09

1E+10

1E+11

1E+12

0.1 1 10

放射

能濃

度(B

q/g)

停止後の経過時間 (y)

AP-Total U237PU241 CM242ACT-TOTAL KR 85SR 89 SR 90Y 90 Y 91ZR 95 NB 95NB 95M RU103RH103M RU106RH106 TE129TE129M I131XE133 CS134CS137 BA137MBA140 LA140CE141 PR143CE144 PR144PR144M ND147PM147 PM148MEU156 FP-TOTALTOTAL

Time after reactor shutdown (y)

Radi

oact

ivity

(Bq/

g)

22-May-2012

Fission Product Release a Strong Function of Temperature

11

IAEA Training in Level 2 PSA Source Term Phenomena http://www-ns.iaea.org/downloads/ni/training/specific_expert_knowledge/psa-level2/M3%20%20Source%20Term%20Phenom.pdf

22-May-2012

Concentration Ratio of Sr-90 to Cs-137 in Soil

http://www.mhlw.go.jp/stf/shingi/2r98520000023nbs-att/2r98520000023ng2.pdf

22-May-2012 12

Measured

Concentration Ratio of Sr-90 to Cs-137 in River Water

22-May-2012 13

http://www.mhlw.go.jp/stf/shingi/2r98520000023nbs-att/2r98520000023ng2.pdf

Measured

Concentration Ratio of Pu-238 to Cs-137 in Soil

22-May-2012 14

Measured

http://www.mhlw.go.jp/stf/shingi/2r98520000023nbs-att/2r98520000023ng2.pdf

Radiation dose rate in the airplane

22-May-2012 15

Monitoring by Car

22-May-2012 16

http://www.meti.go.jp/earthquake/nuclear/pdf/120427/monitor01_02.pdf

Dose rate at 1m above the ground surface ● >=19μSv/h ● < 1.0μSv/h

Air dose rates at the height of 1m above the ground surface

22-May-2012 17

http://radioactivity.mext.go.jp/en/contents/4000/3179/24/1270_1216.pdf

Total accumulation of Cs-134 and Cs-137 on the ground surface

22-May-2012 18

http://radioactivity.mext.go.jp/en/contents/4000/3179/24/1270_1216.pdf

Results of Airborne Monitoring Survey by MEXT

22-May-2012 19

(111006 MEXT Press Release) http://radioactivity.mext.go.jp/en/

contents/4000/3175/24/ 1270_1006e.pdf

Cs concentration in farm soil

22-May-2012 20

http://www.s.affrc.go.jp/docs/press/pdf/120323_03_bunpuzu.pdf

Bq/kg

Mechanism of the sewage treatment facility

22-May-2012 21

http://www.mlit.go.jp/crd/sewerage/mechanism-types/pdf/p84.pdf

Cs Concentration in Incinerated Sewage Sludge in Tokyo

22-May-2012 22

y = 1.57E+04e-3.81E-03x

y = 5.21E+04e-5.31E-03x

y = 1.92E+04e-4.90E-03x

y = 1.39E+04e-4.15E-03x

y = 1.02E+04e-4.05E-03x

y = 1.15E+04e-4.05E-03x

y = 2.05E+03e-2.87E-03x

y = 1.60E+04e-4.50E-03x

y = 3.50E+03e-4.10E-03x

y = 4.02E+03e-4.15E-03x

y = 4.40E+03e-3.83E-03x

y = 2.96E+03e-3.39E-03x

100

1,000

10,000

100,000

0 100 200 300 400 500 600

Radi

oact

ivity

(Bq/

kg)

Days since April 1, 2011

A

B

C

D

E

F

G

H

I

J

K

L

Incinerated Sewege Sludge in Tokyo

Cs-134 (decay corrected to April 1, 2011) + Cs-137

Cs Concentration in Sintered Sewage Sludge in Fukushima

22-May-2012 23

y = 8.97E+04e-6.93E-03x

y = 9.19E+04e-6.96E-03x

y = 1.82E+05e-6.95E-03x

1,000

10,000

100,000

1,000,000

0 100 200 300 400

Radi

oact

ivity

(Bq/

kg)

Days since April 1, 2011

Cs-134Cs-137Cs total

Sintered Sewage Sludge in Fukushima

Management of wastes arising from decontamination and

contaminated waste such as incinerator ash

22-May-2012 24

Combustible material

>100kBq/kg

>8kBq/kg

Final disposal

Same measure as waste out of specified area

Same measure as designated

waste

Specified waste 500 kt 60 kt/y 15～31 Mm3

Waste in specified area by law Designated waste

Controlled landfill site (existing) Interim Storage

Volume reduction

Monitoring is done by Government

Temporary storage

Flow Chart of Specified Waste and Wastes generated from decontamination (in Fukushima)

Soil/Waste from decontamination

≦8kBq/kg

Incinerator Ash

≦100kBq/kg

Incineration

Incineration

Combustible

>8kBq/kg

Specified waste ～80kt/y 1.4～13 Mm3

Designated waste

Controlled landfill site (existing)

Isolated type landfill

Monitoring is done by Government

Flow Chart of Specified Waste and Wastes generated from decontamination (out of Fukushima)

Soil/Waste from decontamination

≦100kBq/kg >100kBq/kg

>8kBq/kg

Incineration

Combustible Combustible material

Incinerator Ash

Incineration

Temporary storage

Existing landfill site in Japan

22-May-2012 27

Landfill site for hazardous industrial wastes (Isolated type)

Landfill site for domestic wastes and industrial wastes

(Leachate-controlled type)

http://www.env.go.jp/en/recycle/manage/waste.html

Landfill site for stable industrial wastes] (Non-leachate-controlled type)

Concept of Temporary storage sites

Tank for checking radioactivity in leachate* Except for the case of temporary storage at the

site

Sandbags

embankment

Waste in the flexible container bag

Collecting drain pipe*

Impervious layer or sheet

Monitoring of radioactivity in ground water

Protective layer

22-May-2012 28

Basic Concept of The Interim Storage Facility

On October 29, the Ministry of the Environment presented the “Basic Concept of the Interim Storage Facility Required for Handling of Environmental Pollution by Radioactive Materials Associated with TEPCO’s Fukushima Daiichi NPP Accident”

Temporary storage sites will be established in each city, town, and village or community. In the Special Zones for Decontamination, the sites will be established by the Ministry of the Environment with the cooperation of cities, towns, and villages. In other areas, the sites will be established by the cities, towns, and villages with the financial and technical responsibilities fulfilled by the government.

In Fukushima Prefecture, within about 3 years from the full-scale start of soil/waste transfer to temporary storage sites, transfer to the interim storage facility will be started. The interim storage facility will be established only in Fukushima Prefecture. The location for the facility will be decided by the end of fiscal 2012.

Within 30 years from the start of transfer to the interim storage facility, final disposal will be completed outside Fukushima Prefecture.

22-May-2012 29

Reference Disposal Flow Diagram of Soil and Wastes from Decontamination

22-May-2012 30

http://www.meti.go.jp/english/earthquake/nuclear/roadmap/pdf/111117_assistance_01.pdf

Concept of Interim Storage Facility

22-May-2012 31

Radiation monitoring

Drain of rainwater

Cap (after installation)

Engineered barrier with reinforced concrete

Facility for high concentration waste

Facility for low concentration waste

Waste in the flexible container bag

Sealing coat (upper, side,

bottom)

Monitoring of nuclides in the groundwater

Water collecting equipment

(monitoring of nuclides)

Drain of rainwater

Radiation monitoring

Cover soil Greening

to be constructed under construction during transfer transfer completed after transfer

Cell system which begin the operation from completed section to transfer as soon as possible

Roof for rain inflow prevention

Effectiveness of barrier in containment

32

1E-4

1E-3

1E-2

1E-1

1E+0

1E+1

1E-1 1E+0 1E+1 1E+2 1E+3

被ば

く線

量(μ

Sv/y

)

埋設後の経過時間(y)

飲料水摂取

Cs :100Bq/g55万ton

Barrier 30cm

Kd (ml/g)

0 1 3

10 30

100 300 Cs-134

Cs-137

22-May-2012

Drinking of well water

Expo

sure

Dos

e (μ

Sv/y

)

Time after Storage (y)

Thank you for your attention !

Full-scale decontamination has been just started. Siting and design of the interim storage facility are

now proceeded. Waste management in the Fukushima Dai-ichi NPS is

also very important issue fuel debris, sludge from contaminated water treatment concentrated liquid waste concrete and equipment contaminated by airborne or by

highly contaminated cooling water activated metals contaminated plant and soil, and so on.

22-May-2012 33