1. Interaction of nuclear safeguards and safety requirements when planning for waste disposal
Rebecca Stohr, Craig Everton, Lyndell Evans
MRS Scientific Basis for Nuclear Waste Management Symposium
Sydney, Tuesday 31 October 2017

2. Overview Waste classification Mechanisms for disposal
Termination from safeguards
Disposal of small quantities
Safety-safeguards overlap
Facility types
Waste controls
Safeguards on disposed waste
Interaction of nuclear safeguards and safety requirements

3. Waste Classification
Interaction of nuclear safeguards and safety requirements

4. Categories of nuclear material
Safeguards applies to all:
Uranium
Depleted
Natural
Enriched
Thorium
Plutonium
with limited exceptions such as ore
ore residue, Pu-238 > 80 %
Does not apply to other radioactive material
Interaction of nuclear safeguards and safety requirements

5. Classification of safeguarded waste
Long half-lives
Activity
Irradiated
Non-irradiated
Radiologically exempt?
Safeguards assessed at the material level
Facility independent
Image: ARPANSA (adapted from IAEA GSG-1)
Interaction of nuclear safeguards and safety requirements

6. Mechanisms for disposal
Interaction of nuclear safeguards and safety requirements

7. Safeguards 101
All nuclear material must be accounted for and remain accessible to the IAEA for inspection and verification, unless otherwise approved by the IAEA
In Australia, approval must be sought prior to:
Releasing from regulatory control
Conditioning for longer-term storage or disposal
Disposal in a repository
Interaction of nuclear safeguards and safety requirements

8. Termination from Safeguards
Safeguards do not automatically terminate on disposal
Obligations set out in Comprehensive Safeguards Agreement
Treaty-level agreement between Australia and IAEA
IAEA pre-approval required
Irrecoverability test: consumption through use, inert dilution or conditioning
Applies to disposal of larger quantities and programs of disposal
Safeguards shall terminate on nuclear material that “has been consumed, or has been diluted in such a way that it is no longer usable…or has become practicably irrecoverable.” —INFCIRC 153 s11
Interaction of nuclear safeguards and safety requirements

9. Disposal of small quantities
Consumption through use
ASNO draft policy:
Pre-approval may not be required for ad-hoc use of small quantities
Typically in range of milligrams to grams
Only applies to thorium, depleted uranium and natural uranium
Must be recorded at the time in locally held records (eg lab book)
Must be reported to ASNO at time of annual inventory
Pre-approval required prior to use of enriched uranium, plutonium
Disposal via dilution
As above, so long as not recoverable and no intention of recovery
Interaction of nuclear safeguards and safety requirements

10. Disposal without termination
Retained waste
“Retained waste…[is] unrecoverable for the time being”—INFCIRC 153 s107(b)(v)
Facility-level safeguards may still apply
Initial verification
Containment and/or
Surveillance
Full safeguards
Practical difference between disposal and safeguards
Concepts of reversibility and retrievability
Interaction of nuclear safeguards and safety requirements

11. Safety-safeguards overlap
Interaction of nuclear safeguards and safety requirements

12. Near-surface disposal
Image: ONDRAF/NIRAS
Multi-barrier system
Drums
Boxes
Vault
Cover
Interaction of nuclear safeguards and safety requirements

13. Practicably irrecoverable TEst
Safety
Environmental vectors
Surface water
Groundwater
Near-neutral conditions
Inadvertent intrusion
Safeguards
Attempted recovery
Aggressive conditions
Images: SA NFCRC
(after ONDRAF/NIRAS)
Interaction of nuclear safeguards and safety requirements

14. Depth of disposal
Image: Posiva Oy
Repository type does not influence whether material is considered practicably irrecoverable for safeguards purposes.
Consideration not given to depth.
Interaction of nuclear safeguards and safety requirements

15. Hierarchy of controls Design optimisation through early consideration:
Type and extent of conditioning
Homogeneity
Total volumes
Interaction of nuclear safeguards and safety requirements

16. Disposal of safeguarded material
Images: Posiva Oy
Safeguarded material can be disposed of, but repository safeguards will remain after release from other regulatory controls
Interaction of nuclear safeguards and safety requirements

17. Waste conditioning and disposal
Free Release
Image: ARPANSA
Safeguarded material
Terminated waste/no ongoing safeguards
Retained waste/facility-level safeguards
Safeguarded waste/retrievable and available for inspection
Waste conditioning and disposal
Interaction of nuclear safeguards and safety requirements

18. Safeguards on Disposed waste
Interaction of nuclear safeguards and safety requirements

19. Safeguards verification prior to disposal
Focus on encapsulation stage:
Last chance check
Micro verification
Every pin, every rod, every assembly
No empties, no substitutions, no resubmissions
Repository safeguards:
Not a set and forget
Macro verification
Satellite imagery, micro-seismic, ground penetrating radar, inspection of nearby excavations and mines
Image: Posiva Oy
Interaction of nuclear safeguards and safety requirements

20. Summary Safeguards do not automatically terminate on conditioning
Early consideration needed
Acceptability and level of ongoing control
Setting/tailoring WAC
Optimising disposal volumes
Avoiding need to recondition
Equitable distribution of costs
Interaction of nuclear safeguards and safety requirements

21. If in doubt, seek early advice from the regulator
In Australia, conditioning and disposal requires pre-approval.
These approvals are straightforward for small amounts but disposal campaigns will take significantly longer to review and seek approval for.
Interaction of nuclear safeguards and safety requirements