3． Management and treatment of decontamination wastes
3.1. Temporary Storage Sites and Final Disposal
3.1.1. Waste Treatment Flow and Necessity of Temporary Storage Sites
As shown in Chapter 1, the “Urgent Implementation Basic Policy on Decontamination” (“Urgent
Implimentation Policy” in this document) (announced on August 26, 2011 by the Nuclear Emergency
Response Headquarters (NERH); hereafter referred to as the “Basic Policy on Decontamination”)
prescribes that, concerning the following description about the disposal of wastes and soil contaminated byradioactive materials: “The National Government shall be responsible for securing disposal sites that
require long-term management as well as safety of such sites, and will create and announce a roadmap toconstruct such sites as quickly as possible.”On the other hand, the Basic Policy on Decontamination also states: “Time is needed to secure andprepare disposal sites that require long-term management. Decontamination might not proceed quickly ifsuch disposal sites must be put in place first.” The Basic Policy on Decontamination stresses the needs of
temporary storage sites as: “It is realistic that such temporary storage site(s) is (are) to be located ineachmunicipality or community has its own individual temporary storage site(s) for the time being to keep soil
and wastes produced by decontamination.”
In response the MOE on October 29, 2011,presented its basic philosophy “Basic Philosophy on Interim
Storage and Other Facilities Required for the Handling of the Environmental Pollution from Radioactive
Materials Associated with the Accident at the Fukushima Daiichi Nuclear Power Station of Tokyo ElectricPower Company” (hereafter referred to as the “MOE Basic Philosophy on Interim Storage”),
The MOE Basic Philosophy on Interim Storage is summarized in Figures 3-1 to 3-3, and includes theflow schematics for treatment of wastes and the roadmap towards the installation of an interim storage
facility in Fukushima Prefecture, where significant amounts of removed soil and other wastes are
anticipated to be produced.
Flow Diagram for Treatment of Specified Waste(*)
and Decontaminated Soil,etc. based on the Act on Special Measures (Fukushima Pref.)(*)Waste within the Countermeasure Area or Designated Waste (the Act on Special Measures, article 20)

Specified Waste
Waste in the Countermeasure Area
(Former Restricted Area, Deliberate
Evacuation Area)

Designated Waste(over 8,000Bq/kg)

Recyclable
Waste

Soil and Waste Generated from
Decontamination Work

Incineration
Combustibles

Incineration

Combustibles

Incinerated ash,etc.

e.g. disaster waste, rubbish after
cleaning homes up, paddy straw,
etc.
RecycleTemporary Storage site

Less than or equal
100,000Bq/kg

Over 100,000Bq/kg
Volume Reduction,etc.

Existing Controlled Landfill Site
(Regarding Specified Waste, utilization of FUKUSHIMAECOTECH is in the process)Interim Storage Facilities

to Final Disposal
Note) Waste other than specified waste less than or equal
8,000Bq/kg is subject to the Waste Management and Public
Cleaning Act (Certain part is subject to the Act on Special
Measures)Note) At the discussion about the plan of the Interim Storage
Facilities, amount of soil and waste which is difficult toestimate at the present such as an amount generated
from follow-up decontamination is also taken into
consideration.

Figure 3-1 Treatment flow of specified and other wastes produced in decontamination(Fukushima Prefecture)80.
80Source: Ministry of the Environment (MOE), “Basic Philosophy on Interim Storage and Other Facilities

161

ForestFarmland

Building

Park,etc.

①Start of Full-fledged②Storage in Temporary Storage site

Earth moundSandbags

Secured by Local Government orcommunity respectively※ except in case of temporary storage on site

③Storage in Interim Storage Facility(less than 30 years)

Only in Fukushima Prefecture(No carry-on from the outside the prefecture)

Waiting for construction

Under construction

建設中

Receiving delivery

Delivery completed

After delivery

搬入中④Final Disposal :Disposal out of Fukushima

Figure 3-2

Treatment of soil and wastes produced in decontamination (Fukushima
Prefecture).

Required for the Handling of the Environmental Pollution from Radioactive Materials Associated with theAccident at the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company” (October 29,2011). Figure 3-3 and Figure 3-3 are generated from the same source.

162Specified Waste
Designated Waste(over 8,000Bq/kg)

Stored at generated site (water
treatment plant, incineration
plant, farm house, etc.)

Soil and Waste Generated from
Decontamination Work
Incineration

Combustibles

Volume Reduction(Incineration, etc.)

Incinerated ash,etc.

Incinerated ash,etc.(*)

e.g. Sewage sludge, ricestraw, compost, etc.

Temporary
Storage Facilities(On-site Storage)

Soil

Waste(*)

5 prefectures: Miyagi, Ibaraki,
Tochigi, Gunma, Chiba

Note) For 5 prefectures(Miyagi, Ibaraki, Tochigi,
Gunma, Chiba)where designated waste
storage is pressing, the government hasplanned to newly establish treatment
facility in each

Combustibles

Other than 5 prefectures of
Miyagi, Ibaraki, Tochigi,
Gunma, Chiba

Disposal Facility (Isolated Type)

Disposal Standard
Pending(*)Decontamination waste inradioactive cesium concentration
exceeding 8,000Bq/kg will be
designated and treated as
designated waste.

Existing Disposal Site

Note) The national government will conduct monitoring after the
disposal of designated waste

Figure 3-3

Treatment flow of specified and other wastes produced in decontamination(areas outside Fukushima Prefecture).

3.1.2. Configurations of Temporary Storage Sites
Facility configurations, their management, and other conditions necessary for temporary storage sites toquickly begin decontamination work are specified in the “Guidelines Pertaining to the Storage of Removed
Soil” as shown in Chapter 2.4 of this Decontamination Report (the “report” in this document).
However, most of the descriptions in the Guidelines are relevant to the prevention of effects fromradioactive materials on human health and the living environment. In the installation of a temporary site,
there are other conditions required, too, such as fire prevention measures.
Basic configurations of temporary storage sites are shown below in more detail, using the classifications
for the wastes to be stored in the temporary storage sites.

（1） Storage of combustibles
Combustibles such as naturally fallen leaves and branches, and intentionally cut branches, etc. generategases by their decomposition and when accumulated, that might lead to a fire. Therefore, they should becovered with gas- and air-permeable waterproof sheets or the like and gas venting pipes should be provided.
Storage conditions of wastes should be checked regularly, and if white smoke or steam, etc. is noticed,
appropriate management measures should be taken by, for instance, measuring the interior temperatures of
the accumulated wastes (Figure 3-4).

（2） Storage of non-combustibles like soil
Non-combustibles like removed soil may be stored after being covered with waterproof (seepage control)
sheets, since they do not generate gases during storage (Figure 3-5).

163

Basic Structure

Thermometer
Breathable Waterproof Sheet
Sandbags for shielding
Degassing pipe (mountain sand, etc.)

Large sandbags for shielding(mountain sand, etc.)

Fence, etc.

Flexible container, Large
sandbag, etc.(Removed
waste : around 1m3)

enough distance
Sandbags, etc.

enough distance
Sandbags, etc. Fence, etc.

Rainwater
Drainage

Drainageslope

Hole for Monitoring
Groundwater

Drain pipe forcollected water

Drainage slope dependingon site condition

Rainwater
Drainage

Drainageslope

Seepagecontrol sheet

Protective layer(supplemental water
Leveling of collection layer)
groundWater Collecting
Tank(as needed)

Groundwater

Figure 3-4 Basic configuration of a temporary storage site above ground for combustibles removed in decontamination work81.

Basic Structure

Breathable Waterproof Sheet

Large sandbags for shielding(mountain sand, etc.)

Fence, etc.

Sandbags for shielding(mountain sand, etc.)

Flexible container, Large
sandbag, etc.(Removed
waste : around 1m3)

enough distance
Sandbags, etc.

enough distance
Sandbags, etc. Fence, etc.

Drainageslope

Rainwater
Drainage
Hole for Monitoring
Groundwater

Drainageslope

Seepagecontrol sheet
Drain pipe forcollected water

Drainage slope dependingon site condition

Protective layer(supplemental water
Leveling of collection layer)
groundRainwater
Drainage
Water Collecting
Tank(as needed)

Groundwater

Figure 3-5 Basic configuration of a temporary storage site above ground for non-combustibles removed in decontamination work.

81Source: Decontamination Information Site (http://josen.env.go.jp/soil/temporary_place.html). Figure 3-5 has the same source.

1643.1.3. Examples of Temporary Storage Sites
Some examples of temporary storage sites cited from the “Temporary Storage Site Installation
Casebook" (August, 2013), which was compiled by the Division of Fukushima Prefecture Decontamination
Measures, are presented here.
As given in Table 3-1, the above-mentioned document gives ten examples of temporary storage sites,
two examples of air dose rate measurements, and an example of a field observation tour to a temporarystorage site.
Figures 3-6 to 3-10 show examples of temporary storage sites located in a swimming pool, a forest, an
abandoned quarry, the vicinity of a condominium, and a dry field.
Table 3-1 Examples collected in the “Temporary Storage Sites Casebook"82
Content

ExampleExamples of installationi) Public facility (Pool) (Koori town)ii) Paddy field (Yugawa village)iii) Plowed field (Kawamata town, Ten-ei village)iv) Forest (Miharu town, Tamakawa village)v) Residents area neighborhood (Koori town, Date city)vi) Land adjacent to paddy field and orchard (Date city)vii) Utilization of mountain sand collection place ruins (Date city)

Measurement of air dosei) Housing development neighborhood (Koori town)

rateii) Plowed field (Kawamata town)

Field inspection party of

Field inspection party of temporary storage site for Ono town inhabitants

temporary storage site

(Kawamata town)

82 Source:

Division of Fukushima Prefecture Decontamination Measures, “Temporary Storage Site
Installation Examples" (August, 2013). (Figure 3-6 to Figure 3-10 are generated from the same source.)165

（1） A temporary storage site using a swimming pool
【 Before installation 】【 After installation 】

Area, etc.
Waste to bedelivered
Form of facility
Storage Capacity

Approx. 2,500m2 (municipal ownership place)
Removed soil and vegetation generated by decontamination of
educational facilities
Semi-underground facility
Approx. 1,100m3 (using weather resistance large sandbags)

Status ofmanagement○Air dose rate (measuring daily (week day))[before delivery] 0.47μSv/h(2012.5)[after delivery] 0.28μSv/h(2013.7)○Radioactivity concentration of the groundwater (measuring
weekly)[Before delivery] N.D.(2012.5)[After delivery] N.D.(2013.7)○Radioactivity concentration of the leachate(measuring when the leachate is discovered)
The facility has been installed with the public pool which was
not used in an earthquake disaster.
It is approx. 30 meters to the most recent residential house.

Location of
installation

Prefecturalroad

Temporarystorage site
(Former swimming pool)

Figure3-6 A temporary storage site using a swimming pool.

（2） A temporary storage site in a forest【 Before installation 】【 After installation 】

Area, etc.

4,683m2 (national forest)

Wastes to bedeliveredRemoved soil and fallen leaves generated by decontaminationof school and school route, etc.

Form of Facility
Storage Capacity

Above ground facility
Approx. 1,788m3 (using flexible container)

Status ofmanagement○Air dose rate (measuring weekly)[Before delivery] 0.26μSv/h(2012.11)[After delivery] 0.14μSv/h(2013.5)○Radioactivity concentration of the groundwater (measuringmonthly)[Before delivery] N.D.(2013.5)[After delivery] N.D.(2013.6)○Radioactivity concentration of the leachate(measuring when the leachate is discovered)

Location of
installation

Temporary storage site

The national forest has been developed for the installation of
temporary storage site. A swamp flows near. (approx. 10 meters
to the swamp )It is approximately 500 meters to the most recent residential
house.

Figure 3-7 A temporary storage site in a forest.

166

Shrine（3） A temporary storage site in an abandoned place digging out sand in a mountain【 Before installation 】【 After installation 】【 Temporary storage site inside 】

Area, etc.

9,894m2 (private land)

Wastes to bedeliveredRemoved soil and vegetation generated by decontamination ofresidential houses and roads

Form of Facility
Storage Capacity

Above ground facility
3,303m3
Breakdown : Combustibles:552m3 Incombustibles:2,751m3(using
flexible container)(city ordering)○Air dose rate (measuring weekly)[Before delivery] 0.33μSv/h(2013.1)[After delivery] 0.57μSv/h(2013.8)○Radioactivity concentration of on-site pond water (measuringmonthly)[Before delivery] N.D.(2012.12)[After delivery] N.D.(2013.8)○Radioactivity concentration of the leachate(measuring when the leachate is discovered)

Status ofmanagement

Figure 3-8 A temporary storage site in an abandoned place digging out sand in a mountain.

167

（4） A temporary storage site near a residential area⑤-1 Residents Area Neighborhood (Koori town)[After installation][Before installation]

Approx. 900m2 (Municipal ownership place)
Removed soil and vegetation generated bydecontamination of residential house
Semi-underground facility
750m3 (using flexible container)○Air dose rate (measuring daily (week day))[Before delivery] 0.62μSv/h(2012.11)[After delivery] 0.26μSv/h(2013.6)○Radioactivity concentration of the groundwater(measuring monthly)[Before delivery] N.D.(2012.11)[After delivery] N.D.(2013.6)○Radioactivity concentration of the leachate(measuring when the leachate is discovered)

Location of
installation

The temporary storage site has been installed using
Green belt between residential area andrailway(Tohoku Main Line) .
It is approximately 10 meters to the most recent
residential house.

The JR Shinkansen

JR Toholu
Main Line

Temporary storage site

Air dose rate (μSv/h)Area, etc.
Wastes to bedelivered
Form of Facility
Storage Capacity
Status ofmanagement

Air dose rate (μSv/h)

Figure 3-9 A temporary storage site in the vicinity of a condominium.

168

（5） A temporary storage site in a dry field[Before installation]

Area, etc.
Wastes to bedelivered
Form of Facility
Storage
Capacity

Status ofmanagement

20,331m2 (private land)
Removed soil,etc. generated by decontamination of residential
house and road,etc.
Above ground facility
Approx. 5,350m3 (using weather resistance large sandbags)○Air dose rate (measuring weekly)[Before delivered] 0.33μSv/h(2012.10)[After delivered] 0.25μSv/h(2013.6)○Radioactivity concentration of the swamp water (measuringmonthly)[After delivered] N.D.(2013.6)* Because water level under the ground is low and specimen
can not be gathered, the swamp water is measured.
○Radioactivity concentration of the leachate(measuring when the leachate is discovered)Mulberry field has been developed for the installation of
temporary storage site.
It is approximately 200 meters to the most recent residential
house.

Ukanizawa

Ootsunaki

Temporary storage site

Air dose rate (μSv/h)

Location of
installation[After installation]

Air dose rate (μSv/h)* Measuring air dose rate at the plural points in the temporary storage site
* Reason why the air dose rate decreased during January to March is considered to be the effectof shielding by snow.

Figure 3-10 A temporary storage site in a dry field.

169

3.2. Wastewater Treatment
3.2.1. Notes of Caution for Wastewater Treatment
Water is used in high-pressure water cleaning of roofs, roads and the like for decontamination as well as
possibly in the cleaning of tools used for decontamination.
Wastewater used in these tasks must be treated appropriately, as it might have been contaminated byradioactive materials. However, most radioactive cesium is in a form that is strongly adsorbed on soil
particles, and hardly any of it will dissolve into the wastewater. Therefore, the central element ofwastewater treatment is to remove fine soil particles contained in the wastewater.

（1） Necessity of wastewater collection and treatment
The “Guidelines Pertaining to Decontamination and Other Measures,“ mentioned in Chapter 2.2 of thisreport specifies that no wastewater treatment is essentially needed in cases where soil sediments are
removed in the decontamination work in decontamination areas (areas subject to the decontamination plansestablished by relevant municipalities).
However, in principle, wastewater should be treated in situations where the wastewater is highly turbidor the wastewater has been collected from high-pressure water washing with vacuum collection of water.

（2） Notes of caution for decontamination of water used for washing
When decontaminating using water, the sequence of decontamination should be determined as shown
below with consideration of water transfer (Chapter 2.2). The wastewater discharge channels should bechecked, the wastewater flow should be dammed up using sandbags and the like as needed to allow finesoil particles contained in it to settle and be collected. Then the supernatant liquid may be discharged(Figure 3-11). Actual scenes and methods of wastewater treatment are shown in Figure 3-12 and Figure3-13. Figure 3-14 shows an example of high-pressure water cleaning equipment with vacuum collection ofwater.
In Fukushima City and other municipalities, there have been examples of formulating decontaminationplans, as seen in Figure 3-15, in consideration of local rainwater and surface water flows, when planningthe decontamination works..

Figure 3-11

Treatment of wastewater used in washing (including sedimentation alreadypresent in the street drains)83.

83Source: Ministry of the Environment (MOE) “Guidelines pertaining to decontamination and othermeasures“ (2nd Edition (amended in December 2014)),
http://josen.env.go.jp/material/pdf/josen-gl02_ver2_supplement1412.pdf),

170

Figure 3-12 Treatment of wastewater used in washing (Kawauchi Village)84

8. Treatment of wastewater from cleaning
Cleaning is essential in the house decontamination, but it is difficult to recover all the wastewater. The
measures such as follows are taken on the site.
①Minimizing use of water with water for the last finish, in advance removing moss, soil, and the like withradioactive materials by hand which deposit on roof, rainwater guttering, etc., then absolutely decreasing
migration of radioactive materials into cleaning water.
(The past 19 times measurement results of wastewater from cleaning: approx. 36Bq/l on average)②Reducing a outflow of radioactive materials to lower basin by installing “filtering device” using zeolite instreet drains to which wastewater is channeled. However, this method requires the establishment of storage
area like temporary storage site, etc. for sedimented soil and spent zeolite.
(The past 19 times measurement results of wastewater from cleaning: approx. 10Bq/l on average after
filtration, resulting in average reduction rate of 73%)
<Example of “Filtering Device” using street drains>
・Because radioactive cesium is almost adhered to soil, “Filtering Device” as shown in the rough sketch below
shall be installed so that muddy water in wastewater does not flow out to lower basin, sedimented soil.
・Very small amount of radioactive cesium contained in supernatant liquid shall be adsorbed to zeolite, etc.
upstream

upstream

downstream

Street drains

Sandbag Sedimented soils, etc.
adsorbing cesium, etc.
Zeolite, etc.
Sandbag

downstream

Example of construction

Figure 3-13 Treatment of wastewater used in washing (Fukushima Prefecture)85.

84Source: Kawauchi Village (October 1, 2013), Decontamination and dose control for villagers to return fromfull evacuation
85Source: Fukushima City (January 2013), Decontamination status in Fukushima City, Fukushima City
(January 2013)

171

Work Summary:Using a unique cleaning effect of the high pressure warm water and thecapture effect of the polyionized water, radiological scattering isprevented and decontamination water is recovered with a suction unit at
the same time.
Work Flow:
Cleaning water is transferred to the cavitation vehicle from the water
truck, polyionized, and then transferred to the cleaner.
High pressure cleaning with the polyionized water from a nozzle (twoplaces) in the cleaner is implemented. Cleaning work is performed
without discharging decontamination water into the neighborhood bysucking it from the outer periphery of the cleaner with the suction unit of
the vacuum suction vehicle at the same time. The recovered
decontamination water has radioactive materials removed bycoagulating sedimentation.

Guide
Water Truck

Cavitation Vehicle

Vacuum Suction
VehicleSucking decontaminationwater from the outer
periphery of the cleaner

WorkerCleaner

Guide

Cleaning is done by jetting polyionizedwater at high pressure from two places
while turning a nozzle.

Figure 3-14

Decontamination of roads by high-pressure washing with vacuum collection of
the water used (Kawauchi Village)86.

Oyama Decontamination Plan

Western District Division and Sequence

Eastern
DistrictFigure 3-15

Decontamination plan taking water channels into account (Arrows indicate
water flow lines)87.

86Source: Kawauchi Village (October 1, 2013), Decontamination and dose control for villagers to return fromfull evacuation

87Source: Fukushima City (January 2013), Decontamination status in Fukushima City

172

3.3. Volume Reduction
3.3.1. Necessity of Volume Reduction
Wastes contaminated with radioactive materials and secondary wastes from decontamination works areproduced in large quantities. Therefore, volume reduction is essential in the process of treatment anddisposal of those wastes, in order to reduce the total amount of waste produced and to secure the storagesites. Combustible wastes contaminated with radioactive materials need to be stabilized to prevent theirdecomposition and emission of unpleasant odors. Intermediate treatment by incineration and other means
can reduce the disposal volume to around one-twentieth to one-fifth of the original volume.

3.3.2. Volume Reduction Methods
There are many volume reduction methods from physical processes such as simple compression andcrushing to chemical processes such as incineration and melting. Characteristics of each method aresummarized in Table 3.2.
Table 3-2 Comparison of volume reduction methods88
MethodVolumeDecontamination
reduction
Workability
effecteffectVolumereduction
rate (%)

Measures

Secondary
waste

Effluent gas

much

Effluent gas

much

Effluent gas

littleMelting

○

○

△

～99

High
Temperature
Incineration
Low
Temperature
Incineration

○

○

△

～90

Drying

△

×

○

5～30

---

none

Cleaning

△

△

○

5～10

Wastewater

much

Classification

〇

△

△

10～90

Wastewater

littleCompression

△

×

○

20～50

---

none

Shredding

△

×

△

～50

Dust

little

○

△

○

50～80

Each method of volume reduction is outlined below, being cited from the “Report on the surveys ofoff-site emergency responses associated with the accident at the Fukushima Daiichi Nuclear Power Stationand the environmental restoration activities88.”（1） Melting method
The melting method reduces the volume of solid wastes by elevating their temperatures by means ofplasma heating and other means up to super high temperatures (above 1,200 °C) and produces stable
molten slag, while achieving a high decontamination effect by volatilizing most of the cesium including
radioactive cesium(hereinafter referred to as ”cesium”) present. But, while the melting method volatilizes
even silicic acids and other substances, treatment of a large quantity of secondary gaseous wastes becomes
88Source: Atomic Energy Society of Japan (December 2, 2013), Report on the surveys of off-site emergency

responses associated with the accident at the Fukushima Daiichi Nuclear Power Station and theenvironmental restoration activities. (Table 3-3 has the same source.)

173

necessary. It is not practical to apply this method to the treatment of large quantities of contaminated wastes,in view of the work conditions at super high temperatures and the cost of fuel to melt the wastes.

（2） High temperature incineration
The high temperature incineration method reduces the volume of contaminated wastes by burning them(using heavy oil and other fuel) at temperatures up to around 1,000 °C in the air, volatilizing containedwater and volatile oxides. Cesium volatilization is limited, but some cesium could be scattered andcontaminate the upper part of incinerator or other parts depending on combustion temperatures andconditions. This method is well established and is able to treat massive wastes.

（3） Low temperature incineration
The low temperature incineration method burns wood and other materials in a reducing atmosphere of
600 to 800 °C, and then carbonizes the cinders for volume reduction. By volatizing carbon and hydrogencontents in the wastes, the volume reduction rate reaches around 90%, and no secondary wastes areproduced because cesium volatilization is restrained. But, on the other hand, the cesium concentration in
the residue becomes higher. This makes it necessary to give special consideration to the handling andstorage methods depending on the concentrations of radioactive materials when radioactivity exceeds 8,000
Bq/kg, although the volume of wastes to be handled is decreased.

（4） Drying
Drying is carried out by heating wastes at the ambient temperature or below 100 °C. Big weight andvolume reductions are achieved in the case of watery sludge. Trees and vegetation materials can be reducedin volume by drying to some extent, and no further secondary treatment is needed regarding decompositionand other undesirable changes.

（5） Washing
The washing method aims at reducing the volume of contaminated wastes by: dissolving the soluble
materials by high-pressure water washing or immersing into water; separating fine particles from larger
solids by suspending the fine particles in the water; and collecting the solids by solid/liquid separation suchas filtration or other means. In this method radioactive cesium is dissolved into water and fine particles
with adsorbed cesium are separated. The target objects can be decontaminated, but the water content of thewaste collected is high and a secondary treatment is needed for volume reduction by drying and othermeans. Furthermore, the liquid collected contains a high concentration of cesium and also needs asecondary treatment for sorption and separation of the cesium.

（6） Classification
Classification is a method to separate and fractionate fine particles such as clay, to which cesium adheres,by sieves, and to reduce the volume of contaminated soil. There are two types of classification methods: thewet method uses a difference in sedimentation order in the water and the dry method uses sieving. The wetmethod gives effective separation, but the amount of secondary waste such as contaminated water increases.
In contrast, the dry method is advantageous in producing no secondary waste, although it is a roughseparation process. If a predetermined radioactivity decontamination effect is obtained in the separation by
the particle size, the dry method is effective as a pretreatment method.

（7） Compression
The compression method is a method to reduce the volume by compressing contaminated wastes having
174low bulk densities with a press machine and other means. Because none of the radioactive materials aretransferred, after being processed the wastes contain a higher density of radioactivity per unit volume.
Therefore, it becomes necessary to give consideration to the handling and storage methods. This method iseffective for application to contaminated wastes such as wood, trees and plant materials.

（8） Crushing
The crushing method is applied to contaminated wastes having shapes of a rectangle, circle or the like.
The size of such contaminated wastes is reduced by crushing and densification, and thus the space forwaste storage is reduced. No decontamination effect is obtained, since radioactive materials are nottransferred by the crushing method. It is necessary to be careful not to disperse fine particles whencrushing.
It should be noted that there are diverse wastes produced by radioactive contamination, and bydecontamination, too. Therefore, suitability of individual methods of volume reduction depends on thetarget wastes for application. As shown in Table 3-3, there are cases in which sufficient effects cannot be
obtained in volume reduction.
Table 3-3 Applicability of volume reduction methods for selected target items
ObjectVolumeWeight loss
CesiumRadioactivity
Volumereduction
movement
reduction
methodeffectSoil
Meltingyes
yes
decrease
large

Wood

Grass,
straw

Rice

Concrete
SludgeIncineration

yes

no

increaselarge

Cleaning

yes

yes

decreasesmallClassification

yes

yes

decrease

mediumIncineration

yes

no

increaselarge

Low Temp.
Incineration
Cleaning

yesnoincrease

mediumyes

yesdecrease

small

Compressionnonoalmost same

mediumIncineration

yes

no

increaselarge

Low Temp.
Combustion
Cleaning

yesnoincrease

mediumyes

yesdecrease

small

Compressionnonoincrease

large

Compressionnonoalmost same

small

Shreddingnonoalmost same

mediumDryingyesnoincrease

mediumCleaning

yes

yes

decrease

small

3.3.3. Examples of Volume Reduction
A few examples of ongoing volume reduction activities of wastes are shown below.

（1） Crushing
Cut branches produced from the forest decontamination are bulky and need much space if they are
packed as they are and they produce many waste containers. Therefore, a crushing facility can be used to175crush cut branches for more effective packing in flexible containers. An example is practiced in Katsurao
Village and other municipalities.

Nogawa district

Figure 3-16 Branches cut down (left) in forest decontamination and a crushing facility(right)89.

Flexible container filling
Shredding

Injection

Accumulation of combustibles

Figure 3-17

Interior views of a crushing facility: collection (left), putting in and crushing(center), and packing into flexible containers (right).

（2） Chipping
The volume of contaminated wastes produced from decontamination work, such as branches and leaves,
can be reduced by crushing into chips. Then, they can be stored more effectively in the temporary storagesite of limited space. This method is being practiced in Date City and other municipalities.

89Source: Okumura-gumi Corporation (Figure 3-17 has the same source.)

176

Figure 3-18 Before (left) and after (right) chipping90.

Figure 3-19 Chipping machine.

（3） Compression / Packaging
Examples (1) and (2) above are intended to reduce the volume of wastes by crushing so that the materials
become more tightly packed. There is another example of volume reduction by suction compression asshown below.
In this example, the volume is reduced by suction compression using compression storage bags. If
ordinary packing bags are used, the suction openings tend to become clogged with leaves or the bags
become torn by branches, but these difficulties can be overcome by using a special nozzle and a special
compression storage bag, enabling the volume to be reduced to 1/3 to 1/2 of the original volume for
combustibles such as fallen leaves, branches with leaves, grasses, etc.
The compression storage bags have an added odor killing function that controls odors from the
combustibles arising around the temporary storage sites.

90Source: Division of Fukushima Prefecture Decontamination Measures (May 17, 2013), Decontamination

Good Practices Casebook (Figure 3-19 has the same source.)

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Figure 3-20 Before (left) and after (right) compression91.

91Source: Taisei Corporation homepage(http://www.taisei.co.jp/about_us/release/2013/1353289519671.html)

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