Table 4.
Engineered barrier systems (EBS) components of actual or planned geological dis-
posal/storage facilities.
Country
Waste
Wasteform
Container
Backfill
Belgium
HLW
Glass
Stainless steel
Clay, Bentonite,
Quartz sand, Graphite
SNF
SNF
Steel
Canada
SNF
SNF
Carbon steel, Copper
Bentonite, Sand, Clay,
Crashed rock
China
HLW
Glass
Stainless steel
Bentonite
Czech Republic
ILW
Concrete
Steel
Bentonite
HLW
Glass
SNF
SNF
Finland
SNF
SNF
Copper, Iron
Bentonite, Crushed
host rock
France
ILW
Various
Stainless steel, Con-
crete
Concrete lining
HLW
Glass
Stainless steel, Steel
Bentonite
SNF
SNF
Stainless steel
Bentonite, Disposal
tube
Germany
1
LILW
Not considered as EBS Not considered as EBS
Salt concrete
Japan
HLW
Glass
Carbon steel
Bentonite, Sand
Korea
SNF
SNF
Steel, Copper,
Bentonite, Sand
Russia
HLW
Glass
Steel, Stainless steel Bentonite, Concrete
Spain
SNF
SNF
Carbon steel
Bentonite
Sweden
SNF
SNF
Copper, Iron
Bentonite
Switzerland
HLW
Glass
Steel
Bentonite
UK
LILW
Cement
Steel, Concrete
Cement based
US
TRU
2
/WIPP
3
Various
Steel
MgO
Energies
2022
,
15
, 7804
13 of 24
SNF/YMP
4
SNF
Stainless steel, Ni-
based alloy
-
HLW/YMP
Glass
Stainless steel
-
1
Morsleben;
2
Transuranic waste;
3
Waste Isolation Pilot Plant,;
4
Yucca Mountain Plant (Nevada).
SNF disposal at the YMP was halted during the Obama administration with Blue Ribbon Commis-
sion assigned and tasked with the development of a perspective for the NWM in the US.
Table 5.
Functions of the wasteform (immobilising matrix) and container components of EBS.
Country
Wasteform
Container
Belgium
10,000 y resistance to leaching
Facilitate handling
Canada
10,000 y radionuclide retention
100,000 y containment
Czech Republic
10,000 y radionuclide retention
500–1000 y containment
Finland
Slow rate of release
100,000 y containment
France
100,000 y resistance
Facilitate handling
Germany
1
Not part of EBS
Not part of EBS
Japan
>10,000 y containment and slow re-
lease
1000 y containment, creating
reducing conditions
Korea
Resistance to leaching
1000 y containment
Spain
Slow rate of release
1000 y containment
Sweden (KBS-3)
Slow rate of release
100,000 y isolation
Switzerland
150,000 y low release
Initial period complete con-
tainment
UK (Nirex, RWM)
300–500 y limit release
300–500 y physical integrity,
limit release
US
WIPP: Not part of EBS; YMP: reduce
release rate
WIPP: Not part of EBS; YMP:
>10,000 y resistance to corro-
sion
1
Morsleben.
4.3. Delay of Radionuclide Release
The EBS of GDF has a finite lifetime and its role is to minimise and significantly delay
the release of radionuclides into the geological formation. Durable materials are therefore
preferred for EBS including the wasteform and container materials (see, e.g., Figure 6b).
Based on known corrosion rates of EBS materials in each specific case (
r
, m/y), it is possible
to estimate their lifetimes
t
EBS
from the equation
t
EBS
= L
EBS
/r
(5)
where
L
EBS
is the critical dimension of barrier, e.g., the wall thickness of the container (
10
mm) or vitreous wasteform block half-diameter (
20 cm). Figure 7 illustrates currently
available estimates of initial rates of corrosion and residual (steady state rates in saturated
conditions when the material is confined in contact with its corrosion products) of durable
ceramics, glasses, and corrosion-resistant metallic alloys [33].
Energies
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