Early-Time Signatures of a Nuclear Detonation in Urban Areas
Abstract
A nuclear attack in urban areas will result in atmospheric dispersion of radiological debris that will cause excessive radiation exposure of the surrounding urban materials and atmosphere. Because high-level radiation exposure can significantly modify the status of radiation-absorbing media, abrupt property changes in air and land materials can indicate the presence of radiological debris. The magnitude of these changes depends on the radiological properties of the debris and can be rapidly detected and measured using specialized sensors, so that these changes can be used as early-time signatures of a nuclear attack. Thus, the goal of this proposed work is to identify and evaluate potential early-time signatures of a nuclear attack by investigating the influence of radiation exposure on urban materials and atmospheric environment. Microphysical processes relevant to this effort will be modeled and then incorporated into the DEfense Land Fallout Interpretive Code (DELFIC) of the Department of Defense to enhance the capabilities of the code in predicting fallout transport, deposition, and distribution. To achieve this goal, the proposed work will combine modeling studies at the Georgia Institute of Technology and experimental investigations at the Oak Ridge National Laboratory. Experimental investigations will be focused on the activation of urban materials and the dynamic behavior of radioactive aerosols. Advanced experimental techniques such as two and three-dimensional neutron radiography, electrodynamic particle levitation, and laser-induced breakdown spectroscopy will be employed in these studies. Modeling work is aimed at investigating the ionization of air and developing computer codes to simulate coupled aerosol microphysics, radioactivity-induced electrification, and fallout resuspension, which are not currently considered in DELFIC. The radioactivity-induced electrification part of the computer code will include the charging of radioactive and background aerosols, while other modules will consider particle-particle and particle-surface interactions. These processes will be incorporated into DELFIC and be fully coupled to include the effects of radioactivity-induced charging on fallout transport, deposition, and resuspension. Various nuclear-attack scenarios will be assumed to test the improved capabilities of DELFIC. Georgia Tech Research Institute will support these research efforts by providing deployment and operational context for DELFIC improvement and relevant conditions for its testing. The expected accomplishments of the proposed project include: (i) better understanding of radiological effects that will lead to enhanced diagnostic capabilities of nuclear detonations; (ii) demonstration of post-detonation effects of radiological debris in urban areas; (iii) improved fundamental understanding of the dynamic behavior of radioactive particles; and (iv) advanced radioactivity transport models that can be used for diagnostic applications, prediction of transport and distribution of radioactivity, and response/recovery planning.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 16, 2019
- Source ID
- HDTRA11810023
Entities
People
- Sotira Yiacoumi
Organizations
- Defense Threat Reduction Agency
- Georgia Tech Research Corporation