MODARIA II: WORKING GROUP 6 BIOSPHERE MODELLING FOR LONG-TERM SAFETY
ASSESSMENTS OF RADIOACTIVE WASTE DISPOSAL FACILITIES
IAEA review and enhancement of Biomass methodology
Cartoon of the proposed KBS-3 repository at Forsmark, SwedenVienna, 21 – 24 October 2019
MODARIA II: WORKING GROUP 6 BIOSPHERE MODELLING FOR LONG-TERM SAFETY
ASSESSMENTS OF RADIOACTIVE WASTE DISPOSAL FACILITIES
IAEA review and enhancement of Biomass methodology
Cartoon of the proposed KBS-3 repository at Forsmark, SwedenVienna, 21 – 24 October 2019
Outline
• Background
• Key enhancement areas
• Current status of enhanced report
BIOMASS Background
• BIOMOVS II (1991-1996)
– Developed “Reference Biospheres Methodology”
– International “Reference” models inappropriate
– Instead: methodology and FEP list to encourage transparency, consensus and harmonisation
• IAEA BIOMASS (1996-2001)
– Theme 1 further developed and refined the methodology
– Acknowledged there was further work to do
BIOMASS Background
• BIOMASS methodology has proved very useful– Highlights systematic and transparent approach
– Providing guidance that is adapted to each case
• Wealth of experience in intervening time– Further international collaborations
– Experience from examples of practical application
– Developments in context of assessments
– Scientific developments
WG6 Meetings
• Meetings:– 20-22 April 2016, Brussels– 31 October-3 November 2016, Vienna– 10-12 May 2017, Brugg– 30 October – 3 November 2017, Vienna– 16-18 May 2018, Kerava– 22-25 October 2018, Vienna– 15-17 May 2019, Munich– 21-24 October 2019, Vienna
• Field trip to periglacial analogue • Extensive collaborative work
– Close to 80 participants– Over 100 presentations– Close to 300 pages of workshop
reports
Contributors and Organisations
• BIOPROTA project
– Progress only possible with support of the sponsors of the BIOPROTA project
• ANDRA, BfS, DSA, ENSI, FANC, LLWR, Nagra, NUMO, NWMO, Posiva, RWM, SKB, SSM
– BIOPROTA Technical Support Team
• Support to facilitation and reporting of workshops
• Support drafting of updated guidance
Original BIOMASS Methodology
A. Setting down the assessment context
Output: The underlying premises of the calculation (what is being calculated and why) are stated explicitly.
B. Identification and justification of biosphere system(s)
Output: Biosphere system, or a series of biosphere systems, identified by the principal component types, e.g. climate,
topography etc.
C. Biosphere system description
Outputs: A word picture that provides qualitative and, where appropriate, quantitative description of the biosphere system. A
description of potential exposure pathways.
D. Consideration of potentially exposed groups
Outputs: A list of candidate critical groups and/or other groups of special interest, where appropriate. Fully characterised exposure
groups.
E. Model development
Output: Assessment model.
F. Calculation
Output: Doses or concentrations as required by the assessment context.
FEP list and
screening
Principles for
identification of biosphere systems
Principles for critical
group selection
Data selection
principles
Refinements Identified
Assessment Context
Biosphere system identification and justification
Biosphere system descriptionsHuman actions, wildlife
Potentially exposed group definition human PEGs and
wildlife PEPs
Biosphere and supporting model definition
Conceptual model, mathematical model & data
FEP list and screening
Site under-standing
Data and model
selection principles
Climate development &
downscaling
Geosphere (discharge locations)
Near-surface investigation methods and experience
Landscape development
Principles for critical group selection
Protection of the environment
Confidence buildingCalculation & communication
Enhanced Methodology
• Recogniseimportance of methodology diagram
• Want to emphasiseimportance of– Site understanding:
“Let the site tell the story”
– Integration with overall safety assessment and safety case
– Degree of iteration and interaction
Report Structure
Key enhancement areas
Integration with Safety Case
Integration with Safety Case
Biosphere Narrative v Description
Biosphere Narrative v Description
• Clarification of narrative versus description of the biosphere
• Bridges gap with MODARIA I WG6
• Climate dynamics over the next few thousand years proposed for MODARIA III
Use of Site Information
Use of Site Information
• Site information collected for many purposes– Site characterisation is required for facility design, operational impact
assessment, environmental impact assessment and post-closure safety assessment.
– Highlights the importance of the dialogue between biosphere assessment and system understanding
Biosphere System
• Deciding how to represent the biosphere in assessments
PEGs and PEPs
• Guidance on Potential Exposure Groups
– Characteristics
– Behaviour
• Guidance on Biota Potentially Exposed Populations
– Selection principles
– Representation in a spatial context
Information Boxes
• Used to provide more detailed guidance on particular topics
Data Selection Principles
• Only minor changes
System Understanding
• Various approaches
• Interaction matrices for system understanding and conceptual model development
Conceptual and Mathematical Models
Conceptual and Mathematical Models
Mathematical Representation
• Increased transparency of mapping conceptual to mathematical model
Current status and plan to print
• Completed report– Concise methodology ready– Final draft in IAEA template ready– Final review and approval until
mid November– IAEA review and printing 2020 (?)
• Supplementary information under development– BIOPROTA report 2020
• So, its too late to join us!…but maybe during next Programme?
Potential papers from Working Group 6
• IAEA guidance on climate and landscape change as an input to defining biosphere characteristics for post-closure biosphere assessments of repositories for radioactive wastes (Paper)
• Approaches to the definition of potentially exposed groups and potentially exposed populations of biota in the context of solid radioactive waste disposal (Paper)
• The updated BIOMASS methodology as illustrated by approaches adopted in various assessments (Review)
• A roadmap of research and development requirements to support applications of the updated BIOMASS methodology (Paper/Opinion)
MODARIA II: WORKING GROUP 6 BIOSPHERE MODELLING FOR LONG-TERM SAFETY
ASSESSMENTS OF RADIOACTIVE WASTE DISPOSAL FACILITIES
IAEA review and enhancement of Biomass methodology
Cartoon of the proposed KBS-3 repository at Forsmark, SwedenVienna, 21 – 24 October 2019
Thank you!