CRTI 07-0103RD: Full Scale RDD Experiments and Models Dr. Lorne Erhardt Group Leader, Radiological Analysis and Defence Defence R&D Canada – Ottawa Public Security S&T Summer Symposium 16 June 2009

Radiological Terrorism RDD Hazard Overview Presentation Outline Radiological Terrorism RDD Hazard Overview What are the major hazards? RDD Experimental Work What do we need to study, why and what we’re doing. Full-Scale RDD Experiments and Models Conclusion

Introduction: Radiological Terrorism

What is Radiological Terrorism? Radiological terrorism is the use of radioactive material to cause harm “Harm” could be a lot of things: Death Acute effects: Radiation sickness Chronic effects: Increased cancer risk Economic effects: Contamination Psychological effects The amount and type of harm that a radiological weapon can inflict depends greatly on the design of the weapon

Types of Radiological Weapons For a radioactive source to be dangerous, it must be put into a configuration that allows people to be exposed to it (accidentally or maliciously) There are two main types of radiological weapons: Radiological Exposure Devices Source deployed in order to irradiate people; Simplest form of radiological attack Radiological Dispersal Devices Radioactive sources dispersed by explosive or non-explosive means

RDD Experimental Work: Objectives and Relevance

Why are we studying RDD effects? Effectiveness of radiological dispersal devices subject to debate "Dirty Bombs" Much More Likely to Create Fear than Cause Cancer  American Institute of Physics, www.aip.org Radiological attacks constitute a credible threat Federation of American Scientists, www.fas.org Strategies to protect first responders, the public and critical infrastructure against RDDs must be made in the planning stage, not in the early period just after an attack. The development of guidelines for first responders dealing with radiological terrorism incidents requires experimentally verified data on the effects of RDDs.

What do we need to determine? For atmospheric dispersion (and other hazard assessment) codes we need the “Source Term” Particle size distribution and spatial distribution We must understand: Mechanism for material break-up Melting, vaporization, solid fracture Energetic mechanisms for spatial distribution Buoyant rise, fragment throw Modifications to source term Agglomeration, shock sintering, secondary aerosolization Many time and distance scales involved This all depends greatly on the design of the device

Understanding RDD Hazards Pre-detonation External hazard, maybe some contamination Detonation gives: Small particles “respirable” < 10 µm Inhalation hazard, cloudshine Medium/large particles 10 – 500 µm Contamination/groundshine downwind Fragments > 500 µm Shrapnel/groundshine near blast Longer term hazards Resuspension, ingestion, skin/wound contamination Need to understand all aspects to quantify hazard

Different stress induced mechanisms result in different initial particle size peaks Phase change Phase change (vapor) (vapor) Phase change Phase change (liquid) (liquid) Stress Solid fracture Solid fracture (across grain (across grain Boundaries) Boundaries) Comminution Comminution peak peak Solid fracture Solid fracture (along grain boundaries) (along grain boundaries) Solid fracture Solid fracture (energy limited (energy limited spall spall ) ) > 100 ? m Particle Size Slide courtesy Sandia Labs Final size distribution can be a combination of several of these Peaks and can be modified by combustion and agglomeration

Desired Source-Term Modelling Capability Desired Capability: Given a suspect package, take a radiograph Also, dose rate measurement and isotope ID Quickly (5 min) model the device to determine potential inhalation and ground-shine hazards Make a determination on disruption and mitigation techniques (and associated consequences) Modelling an RDD is difficult, examples: Disc of ceramic with disc of explosives Uncertainty in downwind hazard Local contamination hazard from ballistic fraction

High Speed Video: February 2007, Valcartier

Regular Speed Video: February 2007, Valcartier

High Speed Video: February 2007, Valcartier

Regular Speed Video: February 2007, Valcartier

Video: Sandia Laboratories

RDD Experimental Work: Progress, Results and Impact

Full-Scale RDD Experiments and Models New CRTI Project is a follow-on from CRTI 03-0018RD “Experimental Characterization of Risk for RDDs” Most ambitious RDD modelling and experimental program to date Will provide a unique dataset Indoor and outdoor explosive tests with coordinated source-term modelling program Federal Government Partners: DRDC Ottawa – RAD/FFSE DRDC Suffield – CTTC DRDC Valcartier – EM Health Canada Natural Resources Canada Environment Canada Academic Partners: Royal Military College Acadia University Industry Partner: International Safety Research International Participants: UK Atomic Weapons Establishment US Sandia National Laboratories New England Complex Systems Institute

Full-Scale RDD Experiments and Models Indoor Explosive Dispersal Experiments (Valcartier) Explosive dispersal indoors, non radioactive Aerosol collection to determine airborne hazard RDD Modelling Program (Ottawa) Comprehensive look at existing relevant models Different models for various time and distance scales Create tool kit and best practices for combining models Agent-based modelling approach to cross scales Outdoor Explosive Dispersal Experiments (Suffield) Two series of tests in 2011, each three weeks

Recent Progress CAN/UK/US RDD modelling workshop held in November 2008 in Albuquerque NM Input from a variety of subject matter experts Defined best approaches for both the modelling and experimental programs Modelling effort has focused on evaluation of existing relevant codes, moving on to best practices for integration Modelling of experimental configuration is just beginning (Canada and UK) Experimental parameters defined after last workshop Safety of experiments is first priority, but must maintain relevance to the RDD problem Indoor source term experiments to focus on modelling gaps and to test the defined outdoor experiments

Conclusions Radiological terrorism involves getting a radioactive substance into a configuration where it can cause harm RDDs produce different particle sizes leading to different hazards To fully characterize the hazard you need to determine the “Source Term” This is difficult due to the great dependence on: Device design Material properties CRTI 07-0103RD: Full Scale RDD Experiments and Models is addressing these issues Extensive experimental program is designed to fill gaps in and validate the modelling effort International collaboration including UK and US participants Will result in an ability to quickly evaluate emerging threats Already has resulted in increased understanding of relevant issues