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Nuclear Forensics Technical Mission Areas
Nuclear forensics addresses a diverse set of topics related to the collection, analysis, and evaluation of pre-detonation (intact) and post-detonation (exploded) radiological or nuclear materials, devices, and debris, as well as the immediate effects created by a nuclear detonation. Research and development (R&D) in nuclear forensics requires many scientific and technical disciplines to encompass this range of topics.
Four broad Technical Mission Areas (TMAs) describe the focus of R&D goals:
- Pre-Detonation Material and Device Signatures,
- Pre-Detonation Analysis Methods and Tools,
- Post-Detonation Material Collection and Analysis Methods, and
- Post-Detonation Prompt Signal Analysis.
A brief overview of each TMA is provided below.
Technical Mission Area 1. Pre-Detonation Material and Device Signatures
Physical, chemical, and isotopic characteristics of a radiological or nuclear material can be used to determine aspects of the material’s history and are therefore important to nuclear forensics. In general, a nuclear forensic signature is a set of measurable characteristics that points to the origin or history of a sample, and may specifically include or exclude the sample from a specific class or category of materials. Physical signatures may include morphology, texture, size, and shape of a material or parts of the device. Chemical signatures may include the elemental or molecular form of the material (e.g., uranium dioxide, plutonium oxalate) and abundances of impurities in the sample. Isotopic signatures reflect the isotopic composition of a sample (indicating its enrichment, burnup, intended or actual use) and may be used to derive the time since the material was last processed chemically.
The R&D focus in these areas includes production, acquisition, and/or retrieval of radiological and nuclear materials of historical interest; laboratory analysis of the materials to document their characteristics; development of production and processing models relating processing parameters (chemical, physical, engineering, machining) to observed product characteristics; assessment of which characteristics persist through (or are modified by) various stages of the production, storage, and transport processes; development of libraries of material characteristics; and ultimately evaluation of material characteristics (or combination of characteristics) for their uniqueness or value as nuclear forensics signatures.
Technical Mission Area 2. Pre-Detonation Analysis Methods and Tools
While current methods of sample analysis and data interpretation provide a highly sophisticated level of material characterization and classification, even more advanced methods are requested to identify new signatures and enable new insights into material provenance.
R&D priorities in this area include development of new laboratory analytical methods for determination of spatially and/or temporally distinct features in radiological and nuclear materials; analytical methods that enable determination of new (i.e., previously unrecognized) characteristics and signatures in nuclear or other radioactive materials; mathematical and statistical methods to identify and evaluate correlated material characteristics; modeling and simulation tools to predict forward and inverse relationships between physical/chemical material production processes and measurable characteristics; data visualization methods to enable improved interpretation of data relationships; and data management and knowledge capture tools to enable efficient storage, retrieval, and interpretation of diverse sets of material information.
Technical Mission Area 3. Post-Detonation Material Collection and Analysis Methods
Post-detonation material R&D explores novel methods and advancements in the ability to collect samples of material, analyze radioactive debris, and identify signatures from debris analysis. The overall goal is to obtain accurate debris characterization more rapidly than is currently possible, and to do so in all environments and conditions. Chronologically, this starts with targeted airborne and ground collection methods that are robust under a wide variety of adverse conditions. Methods with the potential to enable remote characterization and quantification of airborne debris are of interest, as are methods that combine collection and analysis, and field deployable systems, with real-time analysis capability. Following sample collection, improved methods are sought for rapid dissolution and pre-concentration of post-detonation debris using environmentally friendly, potentially field deployable, techniques on a reasonable time scale.
The R&D focus for sample analysis includes non-destructive analytical techniques; innovations that rapidly identify and quantify elemental and isotopic constituents (major, minor, and trace) in fresh radioactive fallout debris; and fundamental phenomenology of laser spectroscopy, mass spectrometry, and associated ionization methods. Improvements are also sought in data handling methodologies for compiling, assessing, and interpreting large sets of data; advancing the treatment of data uncertainties; and improving databases of physical constants, such as nuclear cross sections, decay branching ratios, or nuclear energy levels relevant to nuclear forensic analysis.
Technical Mission Area 4. Post-Detonation Prompt Signal Analysis
Post-detonation prompt signal analysis explores R&D that may enable accurate knowledge of the specifics of a nuclear device (e.g., special nuclear material type and mass, device sophistication, etc.) after a detonation. Ideally this knowledge would be available in as short a time as possible with a high degree of confidence. This topic investigates basic physical research on the prompt signatures of nuclear explosive events, such as novel methods for yield determination, device reaction history, or the radiation outputs of these nuclear explosions.
Research could focus on the understanding of unique identifiers of these explosions, measurements of these identifiers, or other topics. In this context, prompt signatures indicate those which can be measured instantaneously to within a few days after the event. These signatures are generally separate from radiochemical signatures.
The federal agencies that sponsor R&D in these technical mission areas include the Department of Homeland Security/Domestic Nuclear Detection Office (DHS/DNDO), the Department of Defense Defense/Threat Reduction Agency (DoD/DTRA), and the Department of Energy/National Nuclear Security Administration (DOE/NNSA). Website links are provided below to facilitate learning more about programs and research solicitations in each of these organizations.
http://www.dhs.gov/increasing-nuclear-forensics-capabilities
http://www.dtra.mil/Research/BasicandAppliedScienceDepartment.aspx