(558a) Using IMASS to Simulate the Tracking/Movement of Special Nuclear Materials

When a facility owns any type of special nuclear material (SNM), it is important to be able to track these materials in the interest of safety and security for the facility and the surrounding area. It is crucial to make sure that a facility can track these SMNs both in transport between facilities (as the NRC tracks) and to track within the facility itself. Part of this would be tracking how moving these SNMs could affect the people in the area during and after the transport of the material. According to Nuclear Regulatory Commission, ?Special nuclear material is only mildly radioactive, but it includes some fissile materials-- uranium-233, uranium-235, and plutonium-239 -- that, in concentrated form, can be the primary ingredients of nuclear explosives. These materials, in amounts greater than formula quantities1, are defined as ?strategic special nuclear material? (SSNM). The uranium-235 content of low-enriched uranium can be concentrated (i.e., enriched) to make highly enriched uranium, the primary ingredient of an atomic bomb.? The iMASS (intelligent Model-Assisted Sensing System) is software modeling toll for fast and reliable detection of SNM developed jointly by The University of Utah, Purdue University and Wright State University. The iMASS is a new theoretical paradigm developed as a new computational methodology consisting of a number of advanced tools applicable to a wide range of interrogation techniques of interest in nuclear material detection and numerical monitoring of the materials of interest. The iMASS was developed using the Nuclear Resonance Fluorescence (NRF) as a test bed, and demonstrated that the software is widely applicable to any kind of nuclear signals or the fusion of multiple signals from different types of detectors. In this paper, we present a different application of the iMASS tool; we use it to simulate the effect of the movements/tracking/trafficking of SNM in some predefined environment. The effects of the movements/tracking/trafficking of SNM are analyzed in terms of radiation level change in predefined environment. Thus, instead of using the NRF signal for which the iMASS tool has been widely verified , we use the radiation level signal as a diagnostic ?marker? in finding the movement/trafficking of the SNM from the known location in predefined environment. We will consider certain amounts of typical SNMs that move (scenario of insiders intending to take these SNMs out from the predefined environment) and show the spatial change of the radiation levels changing in time in regard to the known background. The iMASS tool will give the plots similar to those shown in Fig.1, i.e. will indicate the movements of the radiation peaks in time and space, thus giving the information of the unexpected activities in predefined environment. The challenge is to read very often a low signal imbedded into the background noise and be able to make a confident decision. To validate the simulation data, we will create a simple experiment involving the movement of some radioactive material. References 1. Young, J., Perry, J., & Jevremovic, T. (2010). LightGrid - An Agile Distributed Computing Architecture for Geant4. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 614(1), 154-158. (doi) 2. Perry, J., Xiao, S., & Jevremovic, T. (2008). iMASS: Computational NRF Spectra Signal from Geant4. In 2008 20th IEEE International Conference on Tools with Artificial Intelligence (pp. 541-546). Dayton, OH: IEEE. doi: 10.1109/ICTAI.2008.94 3. Alamaniotis, M., Young, J., Perry, J., Xiao, S., Agarwal, V., Forsberg, P., et al. (2009). Engineering Solution to Nuclear Material Detection at Ports: Introducing the Novel iMASS Paradigm. In Proceedings of 21st IEEE International Conference on Tools with Artificial Intelligence. Newark, NJ. 4. Perry, J., Xiao, S., & Jevremovic, T. (2009). iMASS: Evolved NRF Simulations for More Accurate Detection of Nuclear Threats. In Proceedings of the 17th International Conference on Nuclear Engineering. Brussels, Belgium