Graphical Expert System for Analyzing Nuclear Facility Vulnerability David Sulfredge Oak Ridge National Laboratory December 3, 2002 OAK RIDGE NATIONAL LABORATORY U.S. DEPARTMENT OF ENERGY
Jan 30, 2016
Graphical Expert System for Analyzing Nuclear Facility
Vulnerability
David Sulfredge
Oak Ridge National Laboratory
December 3, 2002
OAK RIDGE NATIONAL LABORATORYU.S. DEPARTMENT OF ENERGY
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Facility Vulnerability Analysis
Objectives Develop models to
predict facility response to military or terrorist weapons
Determine critical locations for enhanced protective measures
Predict collateral effects
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Nuclear Facilities are Vital Assets
Must safeguard U.S. plants About 20% of U.S.
generating capacity Considerable public
concern Need targeting tool for some
facilities Defeat energy infrastructure Defeat WMD production
Potential for serious radiological consequences
ORNL developing Visual Interactive Site Analysis Code (VISAC) to meet these needs
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• Facility Kill Probability• Facility Collateral Effects Estimates• Facility Downtime Estimates• Facility Model Editor• Event/Fault Tree Editor
VISAC Integrates the Following Functions in one Code
Provides VERY FAST “what if” Analysis for Various
Accident/Incident Scenarios
VISAC
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Core damage probability Facility kill probability
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VISAC Weapon Selection• Equipment sabotage option • Blast location
– Chosen from model editor– Chosen from viewer
• Type of blast calculation– Uniform ray trace mode– Direct ray trace mode– Air region mode
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VISAC Blast Propagation
Uniform ray tracing
Directed ray tracing
Air region method
B la s t P o in t
C ritic a lC o m p o n e n t
U n ifo rm R a ys
B la s t P o in t
C ritic a lC o m p o n e n t
B la s t P o in t
C ritic a lC o m p o n e n t
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VISAC Downtime Calculation
DT based on fault tree for facility kill Single component failure Multiple component
failure
VISAC uses a weighted DT sum
DTnet = (1/ Pkill ) Pi* DTi
Compute both serial and parallel repair times to bound answer
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VISAC Geometric Model Viewers
Image from 2-D Viewer, showing a triple orthographic projection
of a turbine building
Image from 3-D Viewer, showing an image of the entire plant
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Viewing Components by Floor Level
First Floor Second Floor
Third Floor
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Building Critical Component List by Floor
Title and highlighted critical component point to each other
VISAC BRL-CAD Model Editor
• Model editor – Create new models– Customize existing models– Move, delete objects
• Creates a BRL-CAD output file
Creates Customized Models in BRL-CAD in Minutes Instead of Days
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Construct Facility from VISAC Library Buildings
• Buildings chosen from libraries• Building positions and orientations can be varied• Screen grid available to aid building placement• Ground level and building “sinkages” can be edited
Event/Fault Tree Editor
• Tree editor – Create new tree– Customize existing trees– Delete trees– Add/Edit consequences – Change failure probability
Creates Customized Event/Fault Trees for use with Customized Geometric Models
VISAC
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VISAC Event Tree Editor• Edit targets on canvas
– Green arrow (Add or delete column)
– Green fork (Split the branch)
– Red X (Collapse the branch)
• Consequences assigned by the user
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VISAC Fault Tree Editor
• Fault trees can be modified– New gates added– New subtrees can be added– Options to copy and paste
• Add new basic events
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Example VISAC Calculation (1)
Sabotage Option Switchyard (S) 50% Steam Generator (SG1A) 50%
Overall Kill Probability 75%
Downtime Serial repair 7.33 months Parallel repair 6.67 months
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Example VISAC Calculation (2)
Most likely sequence leading to core damage highlighted in red
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Simple vs. Detailed Model VISAC Damage Maps for a Generic Two-Loop PWR
Building-level geometry
Detailed plant geometry
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Conclusions
VISAC successfully integrates geometric modeling, damage assessment, and event/fault tree consequence analysis
VISAC’s graphical editing routines can customize library models as needed
VISAC can analyze a wide variety of nuclear facility vulnerability scenarios
Code development work is continuing