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Mitg
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March 20, 2014
DPG Annual Meeting, Berlin
C. Listner, M.J. Canty, A. Rezniczek, G. Stein, I. Niemeyer
Information and Risk-driven
Verification – An Innovative
Approach?
July 11, 2013 Slide 2
1. Introduction
2. Acquisition path analysis & IAEA’s requirements
3. Our methodology
4. A comparative example
5. Nuclear disarmament
6. Summary and outlook
Outline
July 11, 2013 Slide 3
• Problems
• Declaration‘s completeness
• Safeguards measures too material-oriented
• Effectiveness and Efficiency
• Program 93+2
• Extended Declaration (fuel cycle R&D, export)
• Extended Access (research institutions,
decommissioned facilities)
• Environmental samples
• Open source information, remote sensing
• Optimal usage of possible measures
• Improved mandate under the Additional Protocol
Traditional Safeguards
July 11, 2013 Slide 4
• Instead of single nuclear processes, consider State as a
whole
• No more process-specific Safeguard goals
• State-specific technical objectives which are applied based
on proliferation risk
• Objective, reproducible, transparent, standardized,
documented → non-discriminatory
• Facts about a State (State-specific Factors)
• State-level Objectives, Technical Objectives
• Applicable to all types of Safeguards agreements
State-level Concept (SLC)
July 11, 2013 Slide 6
Acquisition Path Analysis
• Acquisition Path (AP): sequence of activities which a State
could consider to acquire weapons usable material
• Acquisition Path Analysis (APA): analysis of all plausible
APs; aim is to determine whether proposed safeguard
measures are sufficient
• Functional requirements
• Visualization
• Reproducibility and automation
• Integration into existing systems and models
• IAEA’s physical model as basis
July 11, 2013 Slide 8
Acquisition Path Structure
• Starts from an artificial origin node
• First process is diversion or import
• Material is then transformed by processes
• Distinguish between misuse of declared facilities and
clandestine activities
• Acquisition Paths end at direct use material
Example of an Acquisition Path
July 11, 2013 Slide 9
Mathematical Background
• Physical Model = mathematical graph
• Route planning software
• Finding paths is a solved problem
• Quantifying attractiveness is based on structured expert judgment
Graph Theory Route Planning Acquisition Path
Analysis
Node Location Material form
Edge Street Process / path segment
Path Route Acquisition Path
Edge Weight Distance Attractiveness
July 11, 2013 Slide 10
• Modular process
• Procedure to be implemented as a software tool
New 3-step Approach
a b c
d e
f
inspector
Network
Modelling
Network
Analysis
Strategic
Assessment
inspectee
July 11, 2013 Slide 11
Network Modeling
• Attractiveness of nuclear processes for the state
• Route planning: shortest, quickest, cheapest way
• GIF: Technical Difficulty (TD), Proliferation Cost (PC),
Proliferation Time (PT)
• Four grades (0..very attractive to 3..very unattractive)
• Overall attractiveness calculated by weighted sum
• Analyst has to make a decision
• Inspection costs
• Technical objectives with underlying safeguards
measures create costs and lead to a probability of
detection (DP)
• Minimization of costs is desirable while preserving
deterrence
1 2 3
July 11, 2013 Slide 12
• Enumerate all paths and sort them according to their
attractiveness
• Not only the shortest path
• Result of Network Analysis, i.e. a complete set of
technically possible Acquisition Paths ranked by
attractiveness
• Visualization of the paths
• No user interaction needed
Network Analysis
1 2 3
July 11, 2013 Slide 13
Strategic Assessment
• State’s strategies: APs + compliant behavior
• IAEA’s strategies: Technical Objectives
Combination (TOCj)
• Detection probability for path i given TOCj : 1 - βij
• Calculation using product rule on the segment’s
detection probabilities
• Modelling using non-cooperative game theory
• Nash-equilibrium as solution
• No zero-sum game
1 2 3
July 11, 2013 Slide 14
Strategic Assessment
• State’s payoffs in decreasing order
• Calculation payoff based on path length: di = l1 / li
• Expected payoff (expected benefit - risk)
• Compliance given TOCj: (1 - αj)0 - αjf
• Non-compliance along path i given TOCj: βijdi - (1 - βij)b
1 2 3
Undetected non-compliant behavior along path 1 di
… …
Undetected non-compliant behavior along path n dn
compliant behavior w/o false alarm 0
compliant behavior with false alarm -f
Detected non-compliant behavior along any path -b
July 11, 2013 Slide 15
Strategic Assessment
• IAEA’s payoff in decreasing order
• Expected payoff (expected benefit - risk)
• Compliance given TOCj: (1 - αj)0 - αje
• Non-compliance along path i given TOCj: -βijc - (1 - βij)a
1 2 3
compliant behavior w/o false alarm 0
compliant behavior with false alarm -e
Detected non-compliant behavior along
any path
-a
Undetected non-compliant behavior along
any path
-c
July 11, 2013 Slide 16
Strategic Assessment
1 2 3
Expected
payoff for
[State, IAEA]
TOC1 … TOCn
AP1
[β11d1-(1-β11)b,
-β11c-(1-β11)a] …
[β1nd1-(1-β1n)b, -
β1nc-(1-β1n)a]
… … … …
APm
[βm1dm-(1-βm1)b,
-βm1c-(1-βm1)a] …
[βmndm-(1-βmn)b,
-βmnc-(1-βmn)a]
Compliant
behavior [-α1f , -α1e] … [-αnf , -αne]
July 11, 2013 Slide 17
• None of the two players can improve its payoff by
unilaterally deviating from the equilibrium strategy.
• Equilibrium payoff (H1*,H2
*)
• Not necessarily the maximum payoff for one or both
players
• Lemke-Howson-Algorithm
• Assumptions
• Payoff matrix is known to both players (total
information)
• Players want to achieve high payoffs (rational
behavior)
Nash equilibrium
1 2 3
July 11, 2013 Slide 18
• State chooses compliant behavior, IAEO chooses TOCj
• H1* = - αjf
• H2 * = - αje
• State would reduce its expected payoff if he chooses any
path
• Expected payoff of a successful nuclear weapon
acquisition – risk of detection < false alarm risk at
compliant behavior
• IAEA increases its false alarm risk if she chooses another
TOC.
• All paths are adequately covered by Safeguards.
Nash equilibrium
1 2 3
July 11, 2013 Slide 19
• State chooses path i, IAEA chooses TOCj
• H1* = βijdi - (1 - βij)b
• H2 * = - βijc - (1 - βij)a
• State would reduce its expected payoff if he chooses any
other path or compliant behavior
• Expected payoff of a successful nuclear weapon
acquisition – risk of detection > false alarm risk at
compliant behavior
• Optimal for State given TOCj
• Path i is covered by Safeguards measures at best given
the available resources and possible detection
probabilities
Nash equilibrium
1 2 3
July 11, 2013 Slide 20
• Effectiveness
• Sufficiency of a safeguards approach
• Assess combination of acquisition paths and safeguards
approaches
• Based on IAEA’s payoffs
• Effectiveness = H2*+100%.
• Efficiency
• Minimum cost equilibrium strategy in which the State
behaves compliantly
• Iteration on budget limit W
Effectiveness and Efficiency
1 2 3
July 11, 2013 Slide 21
• Two States with similar nuclear capabilities
• Some technical differences regarding existing facilities
• Type of commitment is the main difference
• State A with AP & BC → DP=95% for clandestine
• State B w/o AP → DP=20% for clandestine
• Comparing results with respect to
• Number and type of possible Acquisition Paths
• Type of strategies
• Effectiveness of inspectorate
A Comparative Example
July 11, 2013 Slide 32
• State’s strategies: 1041 + 1 (State A), 814 + 1 (State B)
• Inspectorate’s strategies: any combination out of 16 (State
A) resp. 18 (State B) distinct activities
• Costs associated to TOC’s, Cost threshold W
• Computation of Nash equilibrium incl. effectiveness
• No false alarm probabilities modelled
• State’s payoff parameters: d1 / b = 9 (gain of successful
acquisition to loss of perceived sanctions in case of
detection)
• IAEA’s payoff parameters: c / a = 10 (loss of undetected
non-compliance to loss of detected non-compliance)
Strategic Assessment
1 2 3
July 11, 2013 Slide 34
Nuclear Disarmament
• Abstract from IAEA to a general inspectorate
• Two additional edge types
• Diversion from military fuel cycle
• Military processing
• Depending on given commitments:
• Usage of these processes and thus also of some APs
may be compliant
• Modeled via DP=0%
• No modeling of clandestine processes
July 11, 2013 Slide 35
• Presented a new concept for structured high-level planning
of verification activities
• 3-step
• modular
• can be automated
• Good understanding of the tool‘s operating principles
• Should be seen as a tool assisting the analyst
• Gave an example showing plausible results
• Extension to nuclear disarmament possible
Conclusions / Summary
July 11, 2013 Slide 36
Outlook
• Detection probabilities for clandestine processes (“There
are known knowns ... But there are also unknown
unknowns” – Donald Rumsfeld)
• Modeling uncertainty
• Case studies from other verification fields
• HCoC
• CWC
• FMCT
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