Assessing internal contamination after a radiological dispersion device event using a 2x2-inch sodium-iodide detector

The detonation of a radiological dispersion device (RDD) may result in a situation where many individuals are exposed to contamination due to the inhalation of radioactive materials. Assessments of contamination may need to be performed by emergency response personnel in order to triage the potentially exposed public. The feasibility of using readily available standard 2x2-inch sodium-iodide detectors to determine the committed effective dose to a patient following the inhalation of a radionuclide has been investigated. The 2x2-NaI(Tl) detector was modeled using the Monte Carlo simulation code, MCNP-5, and was validated via a series of experimental benchmark measurements using a polymethyl methacrylate (PMMA) slab phantom. Such validation was essential in reproducing an accurate detector response. Upon verification of the detector model, six anthropomorphic phantoms, based on the MIRD-V phantoms, were modeled with nuclides distributed to simulate inhaled contamination. The nuclides assessed included Am-241, Co-60, Cs-137, I-131, and Ir-192. Detectors were placed at four positions on the phantoms: anterior right torso, posterior right torso, anterior neck, and lateral left thigh. The detected count-rate varied with respect to detector position, and the optimal detector location was determined on the body. The triage threshold for contamination was set at an action level of 250-mSv of intake. Time dependent biokinetic modeling was employed to determine the source distribution and activity in the body as a function of post-inhalation time. The detector response was determined as a function of count-rate per becquerel of activity at initial intake. This was converted to count-rate per 250-mSv intake for triage use by first responders operating the detector to facilitate triage decisions of contamination level. A set of procedure sheets for use by first responders was compiled for each of the phantoms and nuclides investigated.M.S.Committee Chair: Hertel, Nolan; Committee Member: Ansari, Armin; Committee Member: Wang, C. K. Chri

Safeguards assessment of gamma-ray detection for process monitoring at natural uranium conversion facilities

Conversion, the process by which natural uranium ore (yellowcake) is purified and converted through a series of chemical processes into uranium hexafluoride gas (UF6), has historically been excluded from the nuclear safeguards requirements of the 235U-based nuclear fuel cycle. With each step in the conversion process from yellowcake to feedstock for UF6, intermediary uranium oxide and uranium fluoride compounds become progressively attractive products for diversion toward activities noncompliant with international treaties. The diversion of this product material could potentially provide feedstock for a clandestine or undeclared enrichment for weapons development for state or non-state entities. With the realization of this potential, the International Atomic Energy Agency (IAEA) has only recently reinterpreted its policies to emphasize safeguarding this feedstock in response to such diversion pathways. This project employs a combination of simulation models and experimental measurements to develop and validate concepts of nondestructive assay monitoring systems in a natural uranium conversion plant (NUCP). In particular, uranyl nitrate (UN) solution exiting solvent extraction was identified as a key measurement point (KMP), where gamma-ray spectroscopy was selected as the process-monitoring tool. The Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility at Oak Ridge National Laboratory was employed to simulate the full-scale operating conditions of a purified uranium-bearing aqueous stream exiting the solvent extraction process in an NUCP. This work investigates gamma-ray signatures UN circulating in the UNCLE facility and evaluates various gamma-ray detector (HPGe, LaBr3 and NaI) sensitivities to UN.Ph.D

2013 Snapshot of NGSI Human Capital Development and Future Roadmap

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MONITORING AND DOSE ASSESSMENT FOR CHILDREN FOLLOWING A RADIATION EMERGENCY—PART II: CALIBRATION FACTORS FOR THYROID MONITORING

Past radiological and nuclear accidents have demonstrated that monitoring a large number of children following a radiological and nuclear emergency can be challenging, in accommodating their needs as well as adapting monitoring protocols and applying age-specific biokinetics to account for various agesand body sizes. This paper presents the derived calibration factors for thyroid monitoring of children of all ages recommended by the International Commission on Radiological Protection using four selected detectors at given times following a short-term(acute) intake of 131I by inhalation. These calibration factors were derived byMonte Carlo simulations using the models of various detectorsand pediatric voxel phantoms. A collection of lookup tables is presented in this paper which may be directly used as a quick reference by emergency response personnel or technical experts performing thyroid monitoring and assessment without doing time-consuming calculations

The enduring legacy of Marie Curie: impacts of radium in 21st century radiological and medical sciences

PurposeThis review is focused on radium and radionuclides in its decay chain in honor of Marie Curie, who discovered this element.Materials and methodsWe conglomerated current knowledge regarding radium and its history predating our present understanding of this radionuclide.ResultsAn overview of the properties of radium and its dose assessment is shown followed by discussions about both the negative detrimental and positive therapeutic applications of radium with this history and its evolution reflecting current innovations in medical science.ConclusionsWe hope to remind all those who are interested in the progress of science about the vagaries of the process of scientific discovery. In addition, we raise the interesting question of whether Marie Curie's initial success was in part possible due to her tight alignment with her husband Pierre Curie who pushed the work along

Summary and conclusions, and abbreviations and acronyms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/175741/1/acm213846_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175741/2/acm213846.pd

The professional radiation workforce in the United States

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/175763/1/acm213848_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175763/2/acm213848.pd