1. IAEA
International Atomic Energy Agency
LILW DISPOSAL CONCEPTS AND
OPTIONS
EXAMPLES AND KEY SAFETY ARGUMENTS
P. ORMAI
IAEA, Waste Technology Section
IAEA
2. IAEA
Presentation aims
• To provide examples of different types of LILW
disposal concepts and facilities in all over the
world
• To consider the reasons and safety arguments for
the different facility types
3. IAEA
Disposal
Disposal options are designed to contain the waste by
means of passive engineered and natural features and
isolate it from the accessible biosphere to the extent
necessitated by the associated hazard.
3
The term ‘disposal’ refers to the emplacement of radioactive
waste into a facility or a location with no intention of
retrieving the waste.
(The term disposal implies that retrieval is not intended; it does not mean
that retrieval is not possible.)
5. IAEA
ISOLATION
RETARDATION
containment
Radioactive
waste
receptor
Isolation:
• means design to keep the waste and its
associated hazard apart from the
accessible biosphere.
• It also means design to minimize the
influence of factors that could reduce
the integrity of the disposal facility.
Containment :
• implies designing the disposal facility to
avoid or minimize the release of
radionuclides.
6. IAEA
Why disposal?
6
• Long time scales for decay
• Ethics / sustainability / security
• polluter pays (this generation pays)
• future generations may lack resources
• societal breakdown
• put beyond use
Common drivers:
• offer final solution (provide disposal capacity)
• increase safety / security
• save money
7. IAEA 7
Quantitative guidance
• Exempt waste: Criteria from BSS – quantities in RS-G-1.7
• Very short lived waste:: Less than 100 days half life
• Very low level waste: Up to 100x clearance levels (radioactivity level
close to that of naturally occurring radioactivity: between 1 and 100 Bq/g).
• Low level waste:
• Near-surface disposal (less than 30 m depth)
• Institutional control for 100 – 300 years
• Less than 400 Bq/g long lived nuclides
• Intermediated level waste:
• need a greater degree of containment and isolation from the biosphere than
provided by near surface disposal
• disposal between deeper than 30 – 50 m (typically a few hundred meters)
• High level waste:
• Heat generation significant
• Activities around 5x104 to 5x105 TBq/m3
8. IAEA
Selection of a disposal option
The selection of a disposal option depends on many factors,
both technical and administrative, such as:
• waste characteristics and inventory
• radioactive waste management policy
• overall disposal strategy in the country (how many facilities)
• national legislative and regulatory requirements
• political decisions
• social acceptance
• the conditions of the country such as climatic conditions
and site characteristics, availability of suitable host media.
9. IAEA
Disposal design aim
• All disposal designs aim to prevent or reduce interaction
between water and waste.
• There are many ways of doing this:
• choice of site (arid region, unsaturated, mountainous site, etc.),
• choice of depth (near surface above/ below grade, intermediate
depth, deep geological),
• water resistant cap (runoff drainage layer, clay barrier)
• long-lived containment (BOSS concept).
• A primary issue also is protection of inadvertent human
intruder and the degree to which a combination of depth of
disposal, institutional controls, and engineered barriers can
be relied upon to prevent or minimize this exposure
scenario.
10. IAEA
Graded approach
• Decisions on disposal technology selection should follow a graded
approach. The following principles are suggested to implement such
an approach:
• Wastes are disposed using the simplest disposal concept available,
consistent with the hazards present and for which safety and environmental
protection can be demonstrated.
•
• The most hazardous wastes are disposed using greater levels of
engineering to provide for increased containment and/or are disposed at
greater depth to increase isolation from the surface environment;
• Where existing disposal facilities are available, consideration is given to
using them before developing new disposal facilities. This may require
additional analyses and regulatory authorizations not addressed by existing
waste acceptance criteria and operating procedures;
11. IAEA
IAEA Waste classification scheme (1)
• The first reference, in my view, should be the IAEA Waste
classification scheme which provides a general system of
classification accommodating various waste types and
disposal solutions.
• This scheme offers a useful initial consideration despite it
identifies only boundaries & provides quantitative guidance
and does not prescribe specific disposal solution for certain
waste types (as specific safety assessment for each
disposal facility is required).
12. IAEA
IAEA Waste classification scheme (2)
General system of classification accommodating various waste types and disposal
solutions
Identify boundaries & provide quantitative guidance
Does not prescribe specific disposal solution for certain waste types –
specific safety assessment for each disposal facility required
13. IAEA
Stepwise approach (1)
• Logically the next step is to explain that selection of a
disposal option may start with a quick screening by using a
simple matrix.
• The task is to adapt the possible disposal solutions to the
particular waste streams.
• Based on the IAEA Waste classification scheme VSLW,
VLLW, LLW, ILW, HLW can be differentiated (special
consideration should be given to DSSR, NORM/TENORM
waste)
• When assessing the disposal options, consideration should
also be given to the volume of waste to be disposed of
14. IAEA
Stepwise approach (2)
• Commensurate with the diverse range of wastes, a diverse range of
disposal solutions have been implemented and proposed for the broad
range of LILW, examples of such being:
• landfill
• unlined or engineered trenches
• engineered surface or subsurface facilities relatively shallow cavities,
former mines, disposal in geological formations and
• borehole disposal.
• geological disposal
• In all cases it is important to recognize the unique hazards of the
specific sub-categories of LILW, for example ILW containing
predominantly short lived radionuclides may not require the same
disposal methods as ILW containing predominantly long-lived
radionuclides. In case of DSRS the half-life (short or long lived) and
the activity (SHARS) plays a key role.
15. IAEA
Stepwise approach (3)
• The next step is to match the possible disposal
solutions to the particular waste streams.
• Safety is the fundamental objective of radioactive waste
disposal. Several options can be ab ovo excluded from
safety consideration point of view.
• Other options can be ruled out on the grounds of technical
reasons (not feasible, difficult to implement, etc.).
• Based on the generic safety considerations, the
characteristics and volume of waste potentially
acceptable or preferable options can then be identified.
• There might be options which need to be more closely
assessed from technical and economic aspects.
16. IAEA
Best option
• One should be, however, aware that the notion of an “optimal”
disposal solution is elusive.
• Deciding what would be an optimal solution is complicated by many
factors that cloud the decision process (e.g., specific waste streams,
policy constraints, and public acceptance, siting constraints, the,
resources available).
• The legal framework can often prescribe the range of disposal solutions
that can be examined. In the end, the disposal system is either safe or
not safe, as determined by regulatory review.
• Therefore this approach is only indicative, and decisions on waste
disposal will need to be made on a case-by-case basis taking into
account actual conditions, waste characteristics, applicable regulatory
requirements the results of a preliminary safety assessment.
•
20. IAEA
Radioactive waste
stream
END POINT
Long-
term
storage
Decay
storage
Surface
trench
Engineered
surface
facility
Intermediate
depth facility
Geologic
repository
BOSS Other
VSLW
Low volume
Large volume
VLLW
Low volume
Large volume
LLW
Low volume
Large volume
ILW
Low volume
Large volume
SNF/HLW
DSRS
Short-lived
Long-lived
SHARS
NORM
Low volume
Large volume
Uranium
M&M
Low volume
Large volume
preferable acceptable
Possible but needs to be assessed
from technical or economic aspects
Not possible for technical reasonNot possible for safety reason
21. IAEA
Exempt waste
• If radioactive materials (waste) meet certain criteria, they
can be exempted.
• If a radioactive material is exempted, it can be disposed of
as if it was not a radioactive material—e.g., if the material
would be municipal solid waste if it were not radioactive,
then it can be disposed of in an authorized municipal solid
waste disposal facility when it receives an exemption.
22. IAEA
Radioactive waste
stream
END POINT
Long-
term
storage
Decay
storage
Surface
trench
Tailing
dam
Enginered
surface
facility
Intermediate
depth facility
Geologic
repository
BOSS
VSLW
Low volume NR ++ + + + NR NR NR
Large volume NR ++ + + NR NR NR NT
VLLW
Low volume NR N ++ ++ + NR NT NR
Large volume NR N ++ ++ + NR NT NT
LLW
Low volume + N + + ++ ++ + +
Large volume + N NR NR ++ ++ + NT
ILW
Low volume + N N N N ++ ++ +
Large volume + N N N N ++ ++ N
SNF/HLW
+ N N N N N ++
DSRS
Short-lived + + + NR ++ + NR +
Long-lived + N N N + ++ ++ ++
SHARS + N N N N ++ ++ ++
NORM
Low volume NR N ++ ++ + + NR NR
Large volume NR N ++ ++ NR NR NR NT
Uranium
M&M
Low volume NR N + ++ + + + NR
Large volume NR N + ++ NR NR NR NT
preferable acceptable Not possible for safety reasonPossible but needs to be assessed
from technical or economic aspects
Not possible for technical reason
23. IAEA 23
Radioactive waste
stream
END POINT
Decay
storage
Surface
trench
Tailing
dam
Engineered
surface
facility
Intermediate
depth facility
Geologic
repository
BOSS
VSLW
Low volume
Large volume
VLLW
Low volume
Large volume
Disposal of VSLW and VLLW
In some countries, VLLW is disposed of in purpose-built disposal facilities,
in the form of earthen trenches with engineered covers.
In other MS, it is disposed of with other waste types, e.g. LLW.
The decision on disposal method is usually made on economic and/or
regulatory grounds.
preferable acceptable Not possible for safety reason Not possible for technical reason
Possible but needs to be assessed
from technical or economic aspects
24. IAEA
Managing decommissioning waste
• Decommissioning and dismantling a 1000 MWe power
station: 5000 – 10 000 m3
• Amount and activity of waste depend upon the selected decom.
strategy: immediate or deferred
• The longer one waits before dismantling and disposal, the
higher is the fraction of waste that can go to conventional
disposal sites, or VLLW site, rather than to LLW
repository (more expensive).
VLLW disposal facilities designed to accept voluminous
rubble from decommissioning activities.
25. IAEA
Oskarshamn, Forsmark, Ringhals and Studsvik (Sweden)
• Above ground facility, non-permeable
engineered bottom plate, leachate directed
to external infiltration bed
• Cover is a mixed layer of bentonite with a
plastic liner, covered with a drainage layer
and a protective layer of moraine and soil
• External infiltration bed with a mixture
Drainage material
Protective layer
Drainage material
Drainage layer
Bentonite & plastic liner
bentonite liner
26. IAEA
Morvilliers (France)
• From the operation and decommissioning of
nuclear facilities
• NORM waste
• Very low specific-activity levels - below a few
hundreds of Bq/g
• Disposal requires no special processing or
conditioning
• Some of the wastes are compacted into bales
and wrapped in polyethylene
1). geomembrane, 2) Clay-based materials 3) 2.5 m-thick clay backfill, 4) 30-cm-thick layer of soil and grass
27. IAEA 27
VLLW arising by decommissioning of Japan
Power Demonstration Reactor (JPDR)
Japan trench-type VLLW repository
EL- CABRIL – Spain
171,500 m3 - 52 % (90,000 m3) can be treated as VLLW
28. IAEA 28
Radioactive waste
stream
END POINT
Decay
storage
Surface
trench
Tailing
dam
Engineered
surface
facility
Intermediate
depth facility
Geologic
repository
BOSS
LLW
Low volume
Large volume
A very wide range of specific activities (~7 orders)
Low amounts of long-lived radionuclides
The boundary between LLW and ILW is not precise
Limits on acceptable levels of long-lived (and other) nuclides will be depend on
the design and location of the particular facility
Options for the disposal of LLW
29. IAEA
Near-surface disposal: facility types
Near-surface disposal facility types: trenches,
engineered vaults, mounds, silos
An engineered or earthen cap is placed over
the waste containers to minimize water
infiltration.
Subsurface disposal facilities: Some
countries prefer disposing of LLW in
subsurface facilities or co-locating LLW with
ILW in deeper facilities.
Permissible activity limits (WAC) generally determined by
post-closure safety assessment:
• total site activity – natural discharges
• specific activity – inadvertent human intrusion
• may be some operational limitations but usually these can
be overcome by remote working
31. IAEA
Trench type disposal concepts
NTS - Area 5 (USA)
Peña Blanca (USA)
Richland (USA)
Ezeiza (Argentina)
Vaalputs (South Africa)
L’Aube (France)
El Cabril (Spain)
31
Australia
32. IAEA
US Ecology Richland, Hanford - USA
• Arid desert environment
• Large trenches
• Waste containers are placed up
to 13.7 m deep in trenches, and
the waste layer stops 2.4 m
below the land surface.
• LLW, NORM and accelerator
wastes
• Additional concrete engineered
barriers for Ra bearing wastes
33. IAEA
VAALPUTS – South Africa
• Arid environment
• Reliance on geological features
• Much less engineering
• Typically lower cost
34. IAEA
Australia
• Dry environment
• Remote areas
• Little possibility of leaching or exposure
• Small to large trenches
• Low volumes of drummed wastes from
mining and uranium ore processing
• Occasional disposals as and when
wastes arise
36. IAEA
Centre de la Manche (France)
• Wet environment
• Early units: trenches
• Waste drums stacked in a tumulus
(mound) formation
• Greater reliance on engineered features
• Disposal began before modern
concepts of safety assessment or safety
cases
• On-going monitoring and surveillance
37. IAEA
Below Grade Vault
• Similar engineering functions to Above Grade Vault
• Waste emplaced below ground, as in trench disposal
• Limited application if shallow water table
38. IAEA
Drigg – UK Centre de l’Aube – France El Cabril – Spain
Rokkasho – Japan Vector – Ukraine Hanford – USA
Mohovce – Slovakia Dukovany – Czech Republic
Püspökszilágy – Hungary
All follow essentially the same design:
• above or just below grade concrete-lined vaults
• split into separate compartments
• mobile weatherproof roof during operation
• multilayer cap
• drainage systems (above and below waste)
• cement encapsulation and backfill
Typical examples: engineered vaults
39. IAEA
Centre de l’Aube (France) 1.
• Disposal facility design
• On surface disposal facility (1 000 000 m3)
• Single layer of engineered concrete vaults
• Single foundation raft located >30 cm above
the water table
• Vault walls made of reinforced concrete
• Concrete cover placed over the wastes once
the vault is filled
• Waste emplacement
• Automated emplacement of wastes in drums
• Mobile weather protection structure (mobile roof)
• Backfilled with gravel or injected with concrete
grout
Separate drainage networks for rain waters
and waters at risk of radionuclide
contamination
40. IAEA
Centre de l’Aube (France) 2.
Hydrogeological context:
• Disposal facility located above the highest levels of groundwater table
• Draining layer (clayey sand) lying on an impermeable substratum (clay)
• Argillaceous sand offers a good compromise between permeability (10-6
m/s) and radionuclide retention
• Groundwater flow is well constrained and drains to a single receptor (the
Noues d’Amance river)
• Lower (regional) aquifers isolated thanks to impermeable argillaceous layers
42. IAEA
ROKKASHO – Japan
Shallow ground vault-type, below groundwater table
The spaces between the drums are sealed by a
cement based mortar grout.
Once the reinforced concrete lid is formed, these
modules are backfilled by bentonite-soil mixture.
48. IAEA
RICHARD - Czech Republic
Former limestone mine subsequently
enlarged to act as a munitions factory
49. IAEA
Silos
• Examples:
• L/ILW disposal at Olkiluoto (Finland)
• L/ILW disposal at SFR Forsmark (Sweden)
• L/ILW disposal at Wolsong (Korea)
• L/ILW disposal at Vrbina-Krško (Slovenia)
50. IAEA
FORSMARK – Sweden
One cavern contains LLW enclosed in
standard ISO containers.
3 of the caverns receive ILW waste.
The concrete silo is also intended for ILW.
51. IAEA
,
The repository is located at the depth of appr.
110 m in granite bedrock.
Entrance from the NNP site
The repository consists of two tunnels for solid
LLW and a cavern for immobilised ILW.
LOVIISA - Finland
52. IAEA
Olkiloutu - Finland
• L/ILW disposal at 60 to 100
meters depth
• Waste generated during the
operation and maintenance of
nuclear power plants
• LLW is compressed into 200-litre
drums
• Non-compressible waste is
packed into steel or concrete
boxes
54. IAEA
Vrbina-Krško – Slovenia
• Site on a river plain from a community
volunteering process
• Silo concept assessed as both feasible and
safe for the inventory of L/ILW to be disposed
• A surface disposal concept was rejected as
being too vulnerable to flooding and erosion
55. IAEA
HIMDALEN - Norway
• Not nuclear country
• Disposal facility for institutional waste
• Storage for Pu-bearing waste
60. IAEA
Disposal at depths of greater than several tens of metres is generally
considered to be the most appropriate option for ILW.
While repositories specifically for ILW exist in some countries, in others, co-
disposal with spent fuel and high level waste is being considered.
Options for the disposal of ILW
Radioactive waste
stream
END POINT
Decay
storage
Surface
trench
Tailing
dam
Engineered
surface
facility
Intermediate
depth facility
Geologic
repository
BOSS
ILW
Low volume
Large volume
61. IAEA
DOE Defense Transuranic Waste Disposal Facility
665 m underground in salt formation
Waste Isolation Pilot Plant (WIPP) - Carlsbad, NM USA
62. IAEA
Radioactive waste
stream
END POINT
Decay
storage
Surface
trench
Tailing
dam
Engineered
surface
facility
Intermediate
depth facility
Geologic
repository
BOSS
NORM
Low volume
Large volume
Disposal of NORM waste (1)
Where is the NORM from:
• Uranium mining and milling
• Uranium overburden and mine spoils
• Phosphate industry wastes (phosphate fertilizers and potash)
• Coal mines (coal ash)
• Oil and gas production scale and sludge
• Waste water treatment sludge
• Metal mining and processing waste (Zinc & lead mining, Al mines)
• Geothermal energy production waste.
• Scrap metal release and recycling
• Rare earth element mining (rarer earth element metallurgy)
63. IAEA
Disposal of NORM waste (2)
• The mining and processing of minerals give rise to large amounts of waste
containing elevated concentrations of naturally occurring radionuclides (NORM,
TENORM).
• This includes waste from U and Th mining and milling, residues from other mining
activities, from the burning of coal and the extraction of metals from raw materials.
• The characteristics of NORM waste differ from those arising from nuclear power
station operations and from the institutional use of radionuclides in several
important respects:
• the volumes are usually much larger, restricting management options both
technologically and economically;
• the half-lives of naturally occurring radionuclides in NORM waste are much longer than
the mainly fission product radionuclides — such that radioactive decay does not result in
a reduction of the associated radiological risks within foreseeable periods of time.
• This means that NORM waste is not suitable for disposal in the ‘classic’ type of
near surface repository. In many cases, the health risks to be addressed in the
management of this waste also come from the chemically toxic or carcinogenic
substances present.
64. IAEA
Disposal of NORM waste (3)
• The principle management options for NORM waste are recycling and
disposal.
• Recycling is only possible for waste with a low radioactivity content and suitable
physical or chemical properties, which limits this option.
• For economical and technical reasons, near or above surface facilities have to be used
in most cases.
• Only for the special cases of waste with high radioactivity levels and comparatively low
volumes is underground disposal a relevant management option.
• The spectrum of options for the disposal of large amounts of NORM
waste ranges from doing almost nothing, if this is acceptable from a
radiological standpoint, to very expensive solutions.
• However, the low cost options are often associated with a significant
environmental impact and the increased costs of the other solutions may
have to be accepted as a way of reducing these impacts.
• Consequently, the choice of a suitable disposal option requires that a balance is struck
between long term risk from the waste and the financial costs of implementing a
disposal solution.
65. IAEA
NORM waste is generally deposited in consolidated and over-covered piles or sludge beds, or
purpose designed repositories with lined cells and protective capping.
In some cases, the waste has been disposed of by using it to backfill disused underground
mines.
Disposal of NORM waste (4)
66. IAEA
Disposal of NORM waste (5)
As it is not feasible to move such large amounts of material, the waste tends to be
disposed of on the site of its generation.
No international consensus on applicable doses.
Stewardship is needed perpetually (as opposed to other near-surface disposal) due to
LL nuclides on surface.
Mukim Belanga, Malaysia NORM Disposal at Sewaqa
69. IAEA
I Surface
II Deep
III Borehole
Intermediate
depth disposal?
Disposal options
Near surface repositories may be
suitable for low activity, short-lived
sources.
Concentration limits
β/γ - typically 10 MBq kg-1
α – up to 50 times less than this
Total activity limits
β/γ - typically 100’s PBq
α - could be 1000 times less than this
For long-lived DSRS with activity levels
exceeding the criteria for disposal in a near
surface repository, GD is the preferred
option.
Acceptable DSRS for deep disposal
No limit in principle BUT
Purpose built deep repository for DSRS: out of the question
Use of existing facilities. where they exist!
Regional or international repositories. will they happen ?
70. IAEA
Existing BOREHOLE facilities
• In the former USSR: „RADON” facilities
• USA: Greater confinement boreholes
– The Nevada test site and WIPP
• South Africa – Pelindaba
• Western Australia – Mt Walton “Intractable Waste
Facility”
• Russian Federation: large diameter borehole (LDB)
71. IAEA
„RADON” facilities
4.6 m
3.6 m
8 4 array
16 pcs wells
Depth = 6 m
Internal diameter = 38 mm
16 pcs wells
Depth = 6 m
Internal diameter = 100 mm
North
Typical arrangement in the FSU
Long-lived sources short-lived sources
Co-disposal in Hungary
72. IAEA
Mt Walton East, Australia
Greater Confinement
Savannah River
2 m diameter
6 m deep
Nevada Test Site
3 m diameter
37 m deep
21 m closure
73. IAEA
DOE TRU Waste Disposal Facilities – Greater
Confinement Boreholes
• Constructed at Nevada Test Site and received
TRU waste (239Pu) and high-activity low-level
radioactive waste (200 m3)
• 13 boreholes constructed, 9 of which received
waste
• Range from 3 to 3.6 m in diameter, and extend to
a depth of 36 m
• Waste packages were placed in the boreholes
from the bottom to appr. 21 m from the surface
• Used from 1984 to 1989
74. IAEA
Borehole capabilities
RADON small 4-6 m PBq Cs-137
source Co-60
W Australia 8 m GBq Cs-137
GBq Am-241
Greater 21 m PBq TRU
confinement
(Nevada Test Site)
disposal
intermediate depth
disposal
storage
75. IAEA
BOSS CONCEPT: Safety Philosophy
‘Borehole facilities offer safe, simple,
economic alternative for all DSRS
Easier’ disposal derives from the small volume
and nature of the waste
No decrease in safety standards, these to be
set by national authorities, backed up by
international guidance, as usual
Existing disposal solutions unsuitable or unacceptable for Cat
1&2 DSRS
77. IAEA
Disposal Options
• Chosen disposal concept will depend on:
• Nature of the waste
• Quantity of waste
• Site characteristics
• Other factors (e.g. socio-political)
Disposal is intended to be permanent, but a programme can be designed to
include retrievability (reversing the action of waste emplacement before or after
closure) and/or reversibility (reverse one or more steps in a repository
development at any stage).
Near-surface options should aim for passive safety through containment
and isolation but may include provision for an extended phase of monitoring
and control (lifetime generally 300 years, but depends !)
Underground options should be intrinsically and passively safe with
defence in depth (multiple barriers)
78. IAEA
All designs aim to prevent or reduce interaction between
water and waste.
There are many ways of doing this:
• choice of site
• arid region
• unsaturated, mountainous site (BUT saturated site can be OK)
• choice of depth
• near surface above/ below grade
• intermediate or deep depth disposal
• water resistant cap
• runoff
• drainage layer
• clay barrier
• long-lived containment (BOSS borehole)
79. IAEA
• Many ways to design repository: different geometries,
different configurations, different materials
• Different disposal systems have been developed, but no
unique design – several types exist suitable for different
conditions.
• Repository type/design depends on:
• Overall disposal strategy in the country (how many facilities?)
• Waste inventories
• The nature of the site (host media) and its surroundings
• Climate
• Legislative restrictions
• Political decisions
• Social acceptance
80. IAEA
• High reliance on ENGINEERED
BARRIERS, supported by natural
site characteristics
• Long term institutional control may
continue after repository closure to
ensure safety
• High reliance on NATURAL
BARRIERS, supported by
engineered and chemical barriers
• Possible post-closure monitoring,
but concept rely on passive safety
81. IAEA
Worth keeping in mind (1)
• There is a great deal of experience in near-surface
disposal
• There is no “best” design for a near-surface disposal
facility
• The design should reflect the circumstances and the level
of hazard or risk
• Available technologies must be assessed.
• Appropriate selection and optimization of technical options
is important in terms of safety, economics and efficiency.
• Technical options based on compliance with national
policies, available funding, human resources and
public sensitivities.
82. IAEA
Worth keeping in mind (2)
• Principal safety arguments include:
• Activity limitation and waste acceptance controls
• Isolation and containment of the wastes
• For at least a few hundred years
• Allows decay
• Limiting contact between the wastes and water
• For many facilities the final cap or cover is the key component
• Radionuclide retardation
• Appropriate management controls and regulatory processes
• The safety case should be developed and used to manage
facility operation and ensure safety requirements, limits,
criteria and conditions are met (Rob’s presentation)
