LAYOUT DESIGN OF UNDERGROUND FACILITIES TAILOREDTO SDM IN THE NUMO SAFETY CASE
Takahiro Goto, Yoichi Yamamoto, Satoru Suzuki, Shigeru Kubota
Nuclear Waste Management Organization of Japan (NUMO)
Mita NN Bldg. 1-23, Shiba 4-chome, Minato-ku, Tokyo 108-0014 Japan
Key words; repository design, underground facility layout, HLW, TRU waste

Abstract
NUMO has developed a generic safety case for geological disposal in Japan. This safety case provides themultiple lines of arguments and evidence to demonstrate the feasibility and safety of geological disposal, which
will encourage stakeholder confidence in the safe implementation of geological disposal and will provide thebasic structure for a safety case which will be applicable to any potential site. This paper provides the outline oftrial underground repository layout designs tailored to the site descriptive models (SDMs) in this safety case.
Suitable emplacement areas were first selected in the repository-scale SDMs based on the Layout Determining
Features (LDFs) defined by the geological features such as faults and permeable rocks. Next, geometry of
repository panels was determined. Regarding the high level radioactive waste, both through type and dead-end
type were applied for the vertical and horizontal emplacement concepts. Then, layout of the repository panel was
designed in the suitable emplacement area considering the Emplacement Determining Features (EDFs) definedby the features such as water inflow from minor faults and fractures in the disposal tunnels, ensuring the space
for the reserved areas. As a result of comparison among the above design options, the dead-end type geometry
with the horizontal emplacement concept could be identified as a relatively efficient and economical approach
which has more flexibility to the geological structures.
1. Introduction
NUMO has developed a generic Safety Case on
geological disposal of high-level vitrified waste(HLW) and various types of radioactive waste
generated from the reprocessing of spent nuclear fueland mixed-oxide fuel fabrication (termed “TRU
waste” in Japan)1, 2. The siting process of a Deep
Geological Repository (DGR) in Japan is based onvolunteerism and no specific site and geologicalenvironments have yet been identified. This safetycase will present technical evidence to support thefeasibility and safety of geological disposal, which
will encourage stakeholder confidence on the safe
implementation of geological disposal and to provide
the basic structure of a safety case that will beapplicable to any potential site. In order todemonstrate the feasibility and long-term safety of
the geological disposal system, the DGR design andthe safety assessment tailored to site descriptivemodels (SDMs) developed in this safety case.
This paper provides the outline of trial repository
designs and specific design examples of undergroundfacilities tailored to illustrative SDMs in this safetycase and focuses on the layout design of theunderground repository.

2. Design premises
2.1. Waste characteristics
In this paper, a DGR would be designed to dispose
HLW and TRU waste. HLW is mixed high-level
radioactive liquid generated from the reprocessing ofspent fuel and glass into stainless steel cylindricalcanister. The amount of HLW was assumed 40,000
containers based on Final Disposal Plan in Japan(2008) .
TRU waste is low-level radioactive waste
generated by the operation and decommissioning of
reprocessing and MOX (mixed oxide) fuel fabrication
plants, containing long-lived nuclides above specificconcentrations. Table 1 shows grouping, total
generation volume and heat production of each TRU
group divided by containment and heat production.
2.2. Site descriptive model
The DGR design would be performed as modelcase tailored to SDMs of Plutonic rocks, Neogene
sedimentary rocks and Pre-Neogene sedimentaryrocks extracted based on studies of the geologicalenvironment in Japan. Although, Pre-Neogene
sedimentary rocks are divided into the coherent faces
and melange face, the case of coherent faces istreated in this study. The features of SDMs are
summarized in Table 2.

6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japan

Table 1. Volume and heat production of TRU waste3
Group
1
2

3

4

Key waste type

Heat
Total volume
production*1
3(m )(W/waste)

Cemented iodine
absorbent
Compressed hulls andends pieces, Returned
waste
Bituminized low-level
concentrate, Mortar,etc.
Cemented combustible,
poorly combustible,
incombustible waste.

319

<1

5792

19

5228

3

L: 5436*2
H: 1309*3

3
60*1: After 25years for the period from manufacturing until thecommencement of the disposal, *2: Waste of low heat generation, *3: Wasteof high heat generation

repository scale with considering the Layout
Determining Features (LDFs). Next, shape and sizeof a disposal panel is determined according to thesuitable emplacement area. Through type anddead-end type are applied for the disposal panel
options. Then, the layout of the disposal panel isconducted in the suitable emplacement area withconsidering the Emplacement Determining Features(EDFs), and connecting tunnels and access tunnels
are installed so that construction, operation andclosure will be carried out efficiently. In addition, it
is considered to ensure the reserved area in thesuitable emplacement area for some difficult cases ofwaste emplacement. Juxtaposition of the DGR for
HLW and the DGR for TRU waste is assumed in thislayout demonstration.

Table 2. Three types of SDMs and their features

Plutonic rocks

ThermalfeaturesHydraulicfeatures

Mechanicalfeatures

Fractured media Hard rock

NeogeneThermalPorous media
sedimentary gradientwith low density Soft rockrocks
3°C/100 m of fractures
Pre-Neogene
Fractured media
sedimentarywith high density Hard rockrocks
of fractures

Chemicalfeatures
Fresh
Reducing condition
Weakly alkaline
SalineReducing condition
NeutralSalineReducing condition
Neutral2.3. Repository concept
The DGR design shall be based on the tunnel
disposal method, from the viewpoints of theapplicability to the geological disposal of heatgenerating waste such as vitrified waste, reliability oftransportation and emplacement techniques tounderground and ease of quality control. The tunnel
disposal method can be divided into dispersed
emplacement in the tunnel and accumulated
emplacement in the tunnel according to the way thewaste is emplaced. Application of these concepts
depends on the heat generation characteristics of theradioactive waste. In order to control the temperaturerise in a repository, the former concept is applied tovitrified waste which has a higher heat generation.
On the other hand, the concept of accumulated
emplacement in the tunnel is applied to TRU wastewith less heat generation relatively.
In current design study, concept options of thevertical pit emplacement and the horizontal PEM
emplacement have been selected for the HLW
disposal, whereas vault emplacement has been for the
TRU waste disposal that was developed in a past
study4 as starting points for structured review ofconcepts. These concepts of EBSs are summarized inFig. 1.
3. Repository layout demonstration
3.1. Procedure to determine layout
Fig. 2 shows the procedure to determine layout ofunderground facilities and requirements. First, thesuitable emplacement area is selected for the SDM in

HLW

TRU waste

Vertical pit emplacement

Gr.1, 2, 4H
Concrete support

Concrete support

Backfill
Gap filler
Concretecell
Waste
packages

Vitrified
waste

Repository concept

SDM

Overpack
BufferDeposition hole

(EBS)

BufferHorizontal PEM emplacement
PEM : Prefabricated EBS Module

Gr.3, 4L
Concrete support
Backfill

Overpack Vitrified waste

Disposal drift

Gap filler

PEM

Concretecell
Waste
packages

Buffer
Metal shell (Bentonite)

Backfill

Fig. 1. Repository concepts
SDM

Design Procedure SDM in repository scale

Selection of Suitable
Emplacement Area
Consider avoiding LDFs

 Mechanical and thermal
properties of host rock

Determination of Shape andSize of a Disposal Panel
Shape...Panel type, Fishbone type

Layout of Disposal Panels
 SDM in repository scale SDM in panel scale

Considering EDFs
Estimation of emplacement efficiency
and securing reserved area

Iteratively
designed SDM in repository scale SDM in panel scale Location of the surface
facilities

Layout of Connecting
Tunnels, Access Ramp andShaftsDesignRequirements• Restriction of adjective transportof RN• Mechanical stability of tunnels• Volume capacity• Mechanical stability of tunnels• Restriction of thermal impact on
EBS• Limit of ventilation wind velocity
in tunnels• Providing sufficient work space• Feasibility and efficiency of work
route
• Efficiency of ventilation anddrainage• Restriction of co-disposal impact• Mechanical stability of tunnels• Feasibility and efficiency of work
route
• Securing drainage path
• Mechanical stability of tunnels• Limit of ventilation wind velocity
in tunnels• Securing evacuation route• Prevention of undesired releaseof radionuclide• Feasibility and efficiency of work
route
• Efficiency of ventilation anddrainage

Fig. 2. Procedure to determine layout andrequirements
3.2. Suitable emplacement area
The suitable emplacement area shall be selectedconsidering the arrangement of disposal tunnels in
the repository scale SDM. The index to assess thesuitable area for disposal has been defined as LDF.
Examples of LDFs are shown in Table 3. LDF is
defined as the geological features such as fault
fracture zones and permeable host rock which havepotential risk for emplacement. LDF would be

6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japanidentified by surface based investigation, and thesuitable emplacement area would be selecting by
precluding LDFs. Handling in the undergroundrepository layout design for LDFs on faults andfactures is shown in Table 4.
Table 3. Geological features serving as LDF
LDFs
Fault, fracture
Local soft areas (suchas serpentine)
Fault, fracture, etc.
Fault, fracture
Formations with hightransmissivity (such as
conglomerate layer)
Fault, fracture
Permeable host rock

Table 4. Handling for LDF on fault and fracture
Categories offaults andfractures
Active fault(e.g. trace lengthof 10 km or
longer)Large-scale fault
with unknown
activity(e.g. trace lengthof 10 km or
longer)Handling in thedevelopment of SDM

Handling in the undergroundfacility design

Define the repositoryscale SDM not to be
included in the possible
repository site.

Not subject to the layout study
due to the reason shown in left
column.

Define the repositoryscale SDM not to be
included in the possible
repository site.

Not subject to the layout study
due to the reason shown in left
column.

Major fault
A fault listed in the(e.g. trace length
repository-scale SDM
of 1 – 10 km)

Small-scale
unconsolidated
fault(e.g. trace lengthof less than1km)

A fault which is notlisted in the repositoryscale SDM but listed in
the SDM as the panelscale

Consolidated
fault andfractures(without afracture zone)

Listed in the SDM as
panel scale

Faults (L ≥ 1 km)

Categorized as a LDF
considering the possibility of
causing difficulties during the
excavation, such as abnormal
flooding. Disposal tunnels
should not be constructed in a
fault and fractures and in therange of its impact.
A disposal tunnel excavated but
no waste nor EBS is emplaced
if it is likely to cause difficulties
with respect to spring water inthe excavation of disposal
tunnels or deposition holes(handled as an EDF).
Waste and EBS emplaced if
there are no difficulties in the
excavation of disposal tunnels
and cavities (handled as an
EDF).

In addition to the fault and fractures, thetransmissivity of the host rock and travel time ofgroundwater can also be a LDF. Disposal tunnels
shall be arranged in a way that the waste is emplaced
preferentially in the area where the groundwater flow
is considered to be relatively slow at repository-scale.
It is better that the groundwater flow velocity of thehost rock around the area is as slow as possible forthe disposal. Thus, disposal tunnels are arranged
preferentially in the area with a lower groundwaterflow velocity and a relatively long travel time. Travel
time estimated by using Darcy velocity field is usedhere as an indicator determined as travel time per unit
travel path length assuming the travel path length ofparticles on the host rock to be 500 m.

Hydraulic gradient

Risks

Assumed risks Collapse of the tunnel
faceduringconstruction
Sudden water inflow
Increased volume ofAssumed risks
groundwater to be treatedduring(drainage volume) during
operation
operation
Possible risks
Fast groundwater flows
related to theShear deformation of the
post-closure
EBS
safetyHydraulic gradientCategories

Groundwater flow analyses have been performed
with consideration of faults and fractures for each
SDM in repository scale. The suitable emplacement
area selected for Plutonic rocks is shown on the
distribution of travel time in Fig. 3. The faults
described on the disposal site scale are characteristic
as the hydrological geological structure of the hostrock, there is a tendency that travel time becomes
relatively short around the faults. Therefore, thedisposal panel shall be installed preferentially in thesuitable emplacement area excluding around thefaults.

Suitable emplacement
area

Groundwater
ratio (y/m)
Traveltravel
timetime(y/m)

Fig. 3. Distribution of travel time based on Darcy
velocity and suitable emplacement area (A planeview at the depth of 1,000 m for Plutonic rocks)
3.3. Disposal panel
3.3.1. DGR for HLW
Through type and dead-end type are applied as thedisposal panel option of the DGR for HLW. A
through type panel has been employed as the DGR
concept in a previous generic safety case in Japan5. Inorder to connect a number of disposal tunnels in thesame direction at regular intervals, appropriate
spacing is set between them in a way as not to affecteach other with respect to thermal impact of waste
and the mechanical stability of tunnels.
The number of disposal panels is examined as 6 to
8 areas considering the volume capacity (40,000
containers of vitrified waste will be accommodated),
the limited ventilation wind velocity (≤ 7.5 m/s) andthe limited temperature (≤ 37 °C) in the tunnels. The
length per disposal tunnel and the number of disposal
tunnels shall be set, so that it can be accommodated
in the suitable emplacement area. Here, the lengthand number of disposal tunnels are determined so thatthe same amount of waste can be emplaced for eachdisposal panel.
As an example, detailed plan views of a disposal
panel for the through type and the dead-end type in

6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japan560m

10m×(48-1)=470m
47@10.0m=470.0m

30m

the case of Plutonic rocks are shown in Fig. 4 and Fig.
5, respectively.

4.44m×(139体-1)+30m×2≒672.7m
138@4.44m+2@30.0m=672.7m

60m

135°

emplacement for the HLW disposal (HLW-V), if thewater inflow rate into a deposition hole is higher than
the following criteria, the deposition hole is judged
unsuitable for the emplacement, and more space isassigned in the reserved area.
 Allowance of the water inflow rate determinedfrom eroded mass of bentonite buffer due topiping Allowance of the water inflow rate determinedfrom the feasibility of emplacement of bentonite
block in the deposition hole
547.2m1190.3m

Fig. 4. Disposal panel of through type
(Vertical pit concept, Plutonic rocks)

Gr3_ドラム缶③
Gr.3
Drum_3

Gr4H_ハル缶・インナーバレル②
Gr.4H
Hull & Inner barrel_2

Gr4H_ハル缶・イ

Gr3_ドラム缶①
Gr.3
Drum_1

Gr.4L Square
Gr4L_角型容器
container
Gr4H_ドラム缶
Gr.4H Drum

Connecting tunnel

Gr4H_ハル缶・イ

Gr3_ドラム缶②
Gr.3
Drum_2

Gr.4H
Hull & Inner barrel_1
Gr4H_ハル缶・インナーバレル①

Gr4L_角

Gr4L_ドラム缶②
Gr.4L
Drum_2

Gr4H

Gr4L_ドラム缶③

Hydraulicgradient

Gr2_キャニスター⑤
Gr.2
Canister_5
Gr2_キャニスター④
Gr.2
Canister_4
Gr2_キャニスター③
Gr.2
Canister_3
Gr2_キャニスター②
Gr.2
Canister_2
Gr2_キャニスター①
Gr.2
Canister_1

Accessshaft
立坑
立坑

Gr4L_ドラム缶②

Gr4L_ドラム缶①727.9m459.8m

24@16.0m=384.0m

Gr.4L
Drum_1
Gr4L_ドラム缶①

Gr.1 Drum
Gr1_ドラム缶

Gr2_キャニスター⑥

Gr2_キャニスター⑤

260@3.36m+20.0m=893.6m
アクセス斜坑へ
To access ramp

Fig. 5. Disposal panel of dead-end type(Horizontal PEM concept, Plutonic rocks)
3.3.2. DGR for TRU waste
A detailed plan view of the underground facilities
for TRU waste in the cases of Plutonic rocks and
Pre-Neogene sedimentary rocks is shown in Fig. 6.
The groundwater is assumed to flow from bottom to
top of the figure. In this case, to ensure the migration
distance as much as possible, waste group 1 and 2,
whose contribution to the evaluation results of theradionuclide migration are large, are arranged in the
upstream side of the groundwater flow, i.e., the lower
side in the zone on the left side. Group 3 is arrangedin the downstream side of the groundwater on theright side so as to minimize the impact of nitrates
contained in group 3 on other waste groups.
3.4. Emplacement efficiency and reserved area
EDF is used for the suitability judgment for thewaste emplacement in the panel scale of the SDM.
Based on EDF, the reserved area shall be set to be
used for disposing waste that cannot be emplaced in
the pre-specified disposal panels. EDF would be
defined as the geological features such as flowing
water from fracture zones which have potential riskfor emplacement of the bentonite buffer andexcavation. EDF would be identified in detailinvestigation in the underground investigation facility
or construction phase, and the suitable emplacement
area should be selected by precluding EDFs.
Water inflow into the deposition hole or the
disposal tunnel is used as an indicator for thesuitability judgment of the waste emplacement, asshown in Table 5. In the case of the vertical pit

Fig. 6. Plane view of underground facilities for TRU
waste (Plutonic rocks & Pre-Neogene sedimentaryrocks)

Gr2_キャニスター④

Gr2_キャニスター③

Gr2_キャニスター②

Gr2_キャニスター①

Gr1_ドラム

Table 5. Criteria for EDFs
Disposal Concept

HLW-V

HLW-H (PEM)

Risks due to EDZ

Criteria

Erosion of buffer due to piping< 0.78 L/min *1< 0.83 L/min *2< 0.51 L/min *3

Feasibility of EBS emplacement< 0.63 L/min

Difficulty of excavation due to
300 L/(min m)
water inflow from tunnel face

TRU waste*1: Plutonic rocks, *2: Neogene sedimentary rocks, *3:
Pre-Neogene sedimentary rocks

In the case of the PEM concept, the buffer isprotected by the metal shell so that it is not likely tobe affected by piping and erosion. Further, there is
the prospect that the volume of water inflow during
the operation period can be restricted by taking water
inflow measures such as grouting and a reverse
surface drainage6,7. Thus, based on results of actual
construction of tunnels, the criterion of EDF in thecase of horizontal emplacement for the HLW
disposal (HLW-H) is determined to be less than 300
L/min of water inflow considering difficulty to the
excavation at the tunnel face. The criterion of EDF
for the TRU waste is determined considering
difficulty to the excavation of disposal tunnels sameas the HLW-H.
In the construction and operation of the repository,
it is expected that the waste emplacement efficiency
will increase or decrease against the prospect at therepository design. Preparing the reserved area with
sufficient margin so that the underground facility can

6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japanbe expanded, it is possible to tailor flexibly tounexpected situations.
In the case of the HLW-V, in order to determine
the required reserved area for the deposition holewhich is not suitable for emplacement of EBS, thewater inflow rate into the deposition hole has been
calculated by 3D groundwater flow analysis. The
groundwater flow analysis has been performed with
100 realizations of the distribution model of fractures
around disposal tunnels by using the stochastic SDM
in the panel scale. The cumulative probability ofwater inflow into the deposition hole by the analysis
is shown in Fig. 7 as an example of the case of
Plutonic rocks. In this case, allowance of the water
inflow rate is applied to the EDF criterion, anddeposition holes with the water inflow rate exceeding
this criterion shall be deemed unsuitable for the waste
emplacement.
Cumulative probability [%]

100
80
60

Criterion for feasibility of
EBS emplacement < 0.63
L/min

40
Criterion for prevention of
piping erosion < 0.78 L/min

20
0
0.001

0.01

0.1

1

10

100

1000

Water inflow into deposition hole [L/min]Fig. 7. Cumulative probability of water inflow into
deposition hole (HLW-V, Plutonic rocks)
Table 6 shows the estimating results of the waste
emplacement efficiency and required reserved areafor each disposal concept and SDM. In the HLW-V,
the reserved area is not required since the waste
emplacement efficiency for Neogene sedimentaryrocks is 100%. On the other hand, in the case of
Plutonic rocks and Pre-Neogene sedimentary rocks, itis necessary to ensure the reserved area
corresponding to 24% and 11% per disposal area,
respectively. It means that the reserved area possible
to dispose 9,600 and 4,400 containers of vitrified
waste in Plutonic rocks and Pre-Neogene sedimentaryrocks, respectively, will be needed as the total
number of waste in the DGR for HLW to be 40,000.
Similar analyses have been also performed for the
disposal tunnels of the HLW-H concept and the TRU
waste. The sections of water inflow ratio exceeding
the criterion of EDF were very small.
3.5. Repository layout
Layout examples of the underground facilities forthe co-disposal concept of the HLW and the TRU
waste in plutonic rocks are shown in Fig. 8. The
contours in the background of these figures represent
the distribution of Darcy travel time ratio.

Table 6. Estimating results for reserved area
Disposalconcepts

SDM
Plutonic rocks

HLW-V

Neogenesedimentary rocks
Pre-Neogene
sedimentary rocks
Plutonic rocks

HLW-H Neogene(PEM) sedimentary rocks
Pre-Neogene
sedimentary rocks
Plutonic rocks
TRU
waste

Neogenesedimentary rocks
Pre-Neogene
sedimentary rocks

Waste
emplacement
efficiency(%)
76.0
100
88.7
99.7

Requiredreserve area(m2)
430,000(9,600 HLWs)
0
310,000(4,400 HLWs)
6,500(120 HLWs)

100

0

100

0

99.5

130

100

0

100

0

As for the capacity of the repository tailored to 3
types of SDMs, it was possible to arrange thedisposal panels which is the predetermined amountand the reserved area which is over the required
amount in the suitable emplacement area after
considering the distribution of faults in each SDM.
For example, in the case of the HLW-V and thethrough type in Plutonic rocks represented in Fig. 8,
the reserved area equivalent to 9,900 vitrified waste
emplacements (440,000 m2) could be ensured byexpanding two reserved areas (R-1, R-2) adjacent to
the disposal panels on the right side (P-2, P-4) against
required area (430,000 m2) equivalent to 9,600
vitrified waste emplacements based on estimating thewaste emplacement efficiency. Furthermore, it will
be possible to ensure two reserved areas (R-3, R-4)
where 6,000 vitrified wastes (270,000 m2) can beaccommodated by expanding adjacent to the disposal
panels on the left side (P-5, P-6). In this case for the
TRU waste repository, the reserved area secured
adjacent to the TRU waste disposal area has an areaof 117,000 m2 (260 m × 450 m), which has enoughmargin for 130 m2 required from the estimation of thewaste emplacement efficiency.
The excavation volume estimated from the layoutof HLW underground facilities for each SDM isshown in Table 7. The size and the excavation
volume of the HLW underground facilities are larger
in the case of the HLW-V concept than the HLW-H
concept for every SDM. The size of the undergroundfacilities is remarkably large in the case of Neogene
sedimentary rocks, because the host rock has a lower
strength and the center-to-center spacing of disposal
tunnels is more required. It is found that the conceptof the horizontal emplacement and the dead-end typeis able to reduce the excavation volume toapproximately 1/2 compared to the concept of thevertical emplacement and the through type. For the
HLW-V concept, the through type in case of Plutonic
rocks and the dead-end type in case of Pre-Neogene
sedimentary rocks are examined, however it can be

6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japanseen that there is no big difference between the
excavation volumes of both. Then, among dead-end
type, horizontal concept is economically preferable tovertical concept.
As a result of comparison among these design
options, the underground facilities combined with thehorizontal emplacement concept and the dead-end
type panel can be identified as a relatively efficientand economical approach which is flexibly applicableto the geological structure.

Hydraulic gradient

Darcy travel time ratio (y/m)

Reserved area
TRU waste
Repository

P-4

R-2

R-1
P-6

P-1

P-5

P-3

P-2

4. Conclusions
In this paper, specific design examples ofunderground facilities tailored to illustrative SDMs in
NUMO safety case and focuses on the layout designof the underground facilities for HLW and TRU
waste were provided.
The layout of underground facilities was designed
taking into consideration discontinuous geologicalstructures such as faults and the groundwater flow.
Regarding the shapes of the disposal panel for HLW,
the through type and the dead-end type were adapted
for the vertical emplacement concept and for thehorizontal emplacement concept, respectively. The
layouts of the underground facilities were provided
for each emplacement concept.
As a result of comparison among these design
options, the underground facility combined with thehorizontal emplacement concept and the dead-end
type panel was identified as a relatively efficient andeconomical approach which is flexibly applicable to
the geological structure.

R-4

REFERENCES

R-3
0

500m

1.

(HLW-V : Through type)Hydraulic gradient

Darcy travel time ratio (y/m)

Reserved area

2.

TRU waste
Repository

3.

P-1

P-2

4.

P-4
P-6

P-3
0

P-5

500m

R-1

(HLW-H : Dead-end type)Fig. 8. Plane view of underground facilities(Co-disposal concept of HLW & TRU waste inplutonic rocks)

5.

Table 7. Excavation volume of DGR for HLW
TypeThroughtype

Dead-end
type

Disposalconcept

HLW-V

HLW-H

SDM
Plutonic rocks
Neogenesedimentary rocks
Pre-Neogene
sedimentary rocks
Plutonic rocks
Neogenesedimentary rocks
Pre-Neogene
sedimentary rocks

Excavation
volume(×103 m3)
7,050

6.

9,030
6,060
3,680
4,040
3,670

7.

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6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japan