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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

A Methodology for Determining the Concentration of Naturally Occurring Radioactive Materials in an Urban Environment

The detection of radioactive sources in an urban setting is greatly complicated by natural background radiation, which emanates from various materials including roadways, sidewalks, soil, and building exteriors. The method presented and demonstrated here represents an effort to characterize the concentration of naturally occurring radioactive material (NORM) in these types of materials. The location surveyed in this work was the Fort Indiantown Gap Combined Arms Collective Training Facility in Lebanon County, Pennsylvania. Over 70 measurements with a high-purity germanium detector were performed to ascertain the NORM concentrations present in the soil, asphalt, gravel, concrete, and walls found throughout the site. Monte Carlo radiation transport calculations were used to obtain detector responses for these various geometries and materials to convert these measurements into NORM concentration estimates. Lastly, synthetic spectra were simulated using the predicted source terms and compared to actual measurements, showing acceptable agreement.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2025

Assessment of Naturally Occurring Radioactive Material (NORM) in Illicit Drugs Using High-Resolution Gamma Spectroscopy

This report documents results assessing the presence of Naturally Occurring Radioactive Material (NORM) in illicit drugs using high-resolution gamma spectroscopy. Specifically, high-purity germanium (HPGe) measurements were conducted at the Drug Enforcement Administration (DEA) South Central Laboratory on 11 samples (referred to as exhibits) including cocaine, fentanyl, heroin, ketamine, LSD, marijuana, methamphetamines, psilocybin mushrooms, and synthetic cannabinoids.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2013

Radiological Impact Associated to Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) from Coal-Fired Power Plants Emissions - 13436

Certain materials used and produced in a wide range of non-nuclear industries contain enhanced activity concentrations of natural radionuclides. In particular, electricity production from coal is one of the major sources of increased human exposure to naturally occurring radioactive materials. A methodology was developed to assess the radiological impact due to natural radiation background. The developed research was applied to a specific case study, the Sines coal-fired power plant, located in the southwest coastline of Portugal. Gamma radiation measurements were carried out with two different instruments: a sodium iodide scintillation detector counter (SPP2 NF, Saphymo) and a gamma ray spectrometer with energy discrimination (Falcon 5000, Canberra). Two circular survey areas were defined within 20 km of the power plant. Forty relevant measurements points were established within the sampling area: 15 urban and 25 suburban locations. Additionally, ten more measurements points were defined, mostly at the 20-km area. The registered gamma radiation varies from 20 to 98.33 counts per seconds (c.p.s.) corresponding to an external gamma exposure rate variable between 87.70 and 431.19 nGy/h. The highest values were measured at locations near the power plant and those located in an area within the 6 and 20 km from the stacks. In situ gamma radiation measurements with energy discrimination identified natural emitting nuclides as well as their decay products (Pb-212, Pb-2142, Ra-226, Th-232, Ac-228, Th-234, Pa-234, U- 235, etc.). According to the results, an influence from the stacks emissions has been identified both qualitatively and quantitatively. The developed methodology accomplished the lack of data in what concerns to radiation rate in the vicinity of Sines coal-fired power plant and consequently the resulting exposure to the nearby population. (authors)

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Effectiveness of mineral soil to adsorb the natural occurring radioactive material (norm), uranium and thorium

A study has been performed on U-soil and Th-soil adsorption of three types of soil collected from Selangor State of Malaysia which are Saujana Putra, Bukit Changgang and Jenderam Hilir. In this study, natural radionuclide (U and Th) soil adsorption based on batch experiments with various initial concentrations of the radionuclide elements were carried out. Parameters that were set constant include pH at 5;amount of soil used was 5 g each, contact time was 24 hour and different initial concentration for each solution of U and Th which is 5 mg/L, 10 mg/L, 15 mg/L, 20 mg/L, 25 mg/L and 40 mg/L were used. The K{sub d} values for each type of soil were determined in this batch experiments which was based on US-EPA method, in order to estimate adsorption capacity of the soil.The K{sub d} values of Th found higher than Kd values of U for all of the soil samples, and the highest was found on the soil collected from Bukit Changgang. The soil clay content was one of factors to influence the adsorption of both U and Th from dilute initial solution. The U-soil and Th-soil adsorption process for all the soil samples studied are generally obeying unimolecular layer Langmuir isotherm model. From Langmuir isotherm, the maximum adsorption capacity for U was 0.393mg/g and for Th was 1.53 mg/g for the soil that was taken from Bukit Changgang. From the study, it suggested that the soil from Bukit Changgang applicable as potential enhanced barrier for site disposing waste containing U and Th.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Assessment of Rare Earth Element Fingerprints for Distinguishing Between Site-Related Wastes and Background - 19441

Actinides such as uranium, thorium and radium are known to be present in sites associated with various phases of the cold war weapons research, development and production. Remediation of these sites as well as others associated with chemical plants that may have generated radioactive actinide-containing wastes have been the focus of the Formerly Utilized Sites Remedial Action Program (FUSRAP) for the past 20 years. The goal is to remediate a site to established cleanup standards as efficiently and cost-effectively as possible. For radiologically-contaminated sites, one potential challenge is the presence of non-FUSRAP media such as naturally-occurring radioactive material (NORM) or technologically-enhanced naturally-occurring radioactive material (TENORM), from non-FUSRAP sources, at concentrations exceeding site cleanup standards. Such NORM and TENORM, and even byproduct radionuclides from other unrelated activities on or near the site, can be mistaken for project waste and thus incur significant additional excavation and waste transport and disposal costs. Past studies have provided examples of NORM and non-FUSRAP waste and described strategies to distinguish them from FUSRAP waste. This paper describes various sources of NORM, summarizes the types of project-related waste at some active FUSRAP sites, and identifies TENORM sites from which radionuclides could possibly migrate via various environmental pathways to nearby FUSRAP sites. The authors also examine two Case Studies that calculate distinctive elemental ratios and are examples of tools which may be used for distinguishing FUSRAP waste from other radionuclides present in natural or other man-made contributors to background. Case Study I examines two bodies of data and calculates distinctive elemental ratios between pairs of rare earth elements (REE) to see if significant differences may exist between such ratios in unregulated coal ash residue, common in fill in well-established towns and cities, and FUSRAP waste. The first group of data, consisting of eighteen sample results, was obtained from the FUSRAP Maywood Superfund Site's historical data while the second was obtained from a paper which provided extensive data (more than 100 samples) on the REE content in fly ash residues from three major coal-producing areas in the United States. This example illustrates statistically significant differences in five of six REE ratios and thus provides a potential tool for distinguishing FUSRAP waste from coal ash-based NORM. Case Study II examines differences in the mean REE:Actinide and REE:REE ratios in Welsbach-impacted sample results to distinguish project waste from background. While the purpose of this study was to distinguish project waste from background levels of the radionuclides of concern (ROC), it provides a good example of how one or more ratios could potentially be used to distinguish FUSRAP waste from NORM. Lastly, the authors recommend that future projects ensure robust characterization, that considers all potential radionuclide contributors from both FUSRAP activities as well as from other contributors to background for the region during the Planning Phase of the Data Life Cycle described within the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM). It is expected that the incremental characterization sampling and analysis costs will be dwarfed by potential savings from efforts to better delineate and limit remediation to FUSRAP wastes rather than other potentially unregulated contributors to regional background. Other agencies or commercial entities with radiological environmental liabilities similar to FUSRAP would benefit from similar considerations of REEs and other radionuclides that could contribute to regional background. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Uranium mining and norm, a North American perspective - 15545

All soils and rocks contain naturally occurring radioactive materials (NORM). Many ores and raw materials contain relatively elevated levels of natural radionuclides and processing such materials can further increase the concentrations of natural radionuclides, sometimes referred to as technologically enhanced naturally occurring radioactive materials (TENORM). Examples of NORM minerals include uranium ores, monazite (a source of rare earth minerals), and phosphate rock used to produce phosphate fertilizer. Such activities have the potential to result in above background radiation exposure to workers and the public. Following a brief review of the sources and exposure from NORM in these varied industries, this paper will then present an overview of uranium mining and recovery in North America including discussion on the methods currently being used, production of NORM materials and wastes associated with these uranium recovery methods and the radiological composition of the NORM wastes produced by uranium recovery. The paper includes descriptions of the methods and associated NORM produced by both conventional (underground, open pit) and in situ recovery (ISR) mining methods and identifies the responsible government agencies in the US and Canada assigned the authority to regulate and control these NORM materials. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Development of an Assessment Method for Radiation Exposure from NORM in Construction Materials - 19032

Once radiological impact is usually considered to be related to nuclear energy accidents and atomic bombs, most of the research on radiation protection has been focused on artificial radionuclides and radioactive waste. Less attention had been given to radiation exposure due to the presence of naturally occurring radioactive materials in raw materials usually considered as not radioactive and used in manufacturing of many building materials. At national level, radiological data from building materials is not available as the control of building materials regarding the content of naturally occurring radionuclides is addressed for the first time in the EU Directive 2013/59/EURATOM. At international level the research developed is largely incomplete: data on the activity concentration measurements of Ra-226, Th-232 and K-40 in building materials used in the construction industry in the EU is non-statistically representative. The data collected are not enough to have an idea of the European situation, but they confirm high concentration of Ra-226, Th-232 and K-40, in some cases. Moreover, most of the research studies carried out in the EU are based on the assessment of the activity concentration index, which was derived for practical monitoring purposes to identify whether a dose criterion is met; to be used only as a screening tool for identifying materials which might be of concern. The dose criterion considers only effective dose due to γ-radiation, but population at home is also exposed to Rn-222 (and Rn-220) from soil, water and building material itself, sometimes to β radiation from superficial materials, and even to Cs-137 from some types of wood. The indoors exposure can be actually much higher than the value assessed with the dose criterion method. Also, in most cases toxic and radioactive components are inseparably. Therefore, all technical questions related to the toxic part of these materials should be addressed: an integrated approach is needed to assess the impacts of using these materials (new materials, recyclates and by-products). Until recently, radiation from natural sources seemed both unremarkable and unalterable - a background phenomenon. It is now known that doses from natural sources and in particular, decay products of radon can be remarkably high within houses in some areas. Therefore, concerning exposure to natural radiation sources, special provisions have been laid down in the EU Directive 1996/28 EURATOM. Still, the radiological evaluation of building materials was not mandatory in this Directive. The most recent EU Directive 2013/59/EURATOM brings some changes concerning the exposure to natural occurring radioactive materials but the previous screening method was kept. An effective dose of 1 mSv/year was set, as a basis for the exposure to radionuclides of natural origin (except for radon). This work seeks to develop an integrated radiological and chemical-mineralogical assessment methodology for realistic exposure scenarios concerning different types of raw materials, by-products and recyclates and used as building materials. The methodology includes the characterization of selected materials accounting for radiological exposure - calculation of effective dose; toxicity assessment - determination of chemical composition and leaching tests, study of changes in the microstructure and consequently in the radon emanation coefficient. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Immobilization of Radioactive Materials Using Porous Iron Composite Media - 18582

High levels of nitrate (NO{sub 3}) derived from agriculture and naturally occurring radioactive materials (NORM), primarily uranium (U) and natural decay chain products that have been mobilized by the influx of oxygenated, high-alkalinity water, are a threat to shallow groundwater resources in California. Porous Iron Composite (PIC) materials were evaluated as a water treatment option in a series of batch experiments. While the use of Zero Valent Iron (ZVI) to address groundwater contaminated with NO{sub 3} or U has been demonstrated, the ability of PICs to chemically reduce and immobilize U and other associated contaminants in oxygenated alkaline groundwater where soluble uranyl-carbonate species dominate and high NO{sub 3} levels may compete for reductive capacity remain a concern. Additionally, ZVI materials have been used to immobilize other redox sensitive radionuclides (e.g., technetium-99 ({sup 99}Tc)) with limited success. Batch tests were conducted using an artificial groundwater surrogate (i.e., CAGW for California Groundwater) containing ∼ 100 mg L{sup -1} NO{sub 3}{sup -}, 200 mg L{sup -1} alkalinity, 100 μg L{sup -1} U, 100 μg L{sup -1} rhenium (Re) as a non-radioactive surrogate for the nuclear fission product technetium-99 ({sup 99}Tc), 100 μg L{sup -1} stable strontium (Sr) as a surrogate for radium (Ra) and the fission product strontium-90 ({sup 90}Sr), and 50 μg L{sup -1} arsenic (As), a common groundwater contaminant. Five gram samples of the PIC material were reacted with 200 mL of CAGW under two different atmospheric conditions to evaluate the impact of O{sub 2}. Batch tests were also conducted in the presence and absence of another oxidized species, NO{sub 3}. At specific time intervals, a small aliquot was collected from each batch treatment for chemical analysis (i.e., U, Re, As, Fe, NO{sub 3}, etc.) and the pH and ORP of the remaining suspension was measured. The PIC was effective at fully reducing NO{sub 3}{sup -} levels over the extended reaction time, even though the reactor pH quickly increased above 8.0 during equilibration. Soluble levels of U and Re decreased in a similar fashion to NO{sub 3}{sup -} in the presence and absence of O{sub 2}. Soluble As levels decreased more rapidly than other contaminants, but remained at ∼ 1 μg L{sup -1}. Very little nitrite (NO{sub 2}{sup -}) was detected in the batch tests, with NH{sub 4}{sup +} levels consistent with the amount of NO{sub 3}{sup -} reduced. Similar rates of immobilization for U, Re, and As were observed in the presence and absence of NO{sub 3}{sup -}. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Development of a Course in Gamma Ray Spectrometry

The majority of undergraduate and graduate students in nuclear science and engineering take a general course in nuclear instrumentation where one of the topics is typically in gamma ray spectrometry. Rarely are courses offered solely on this subject matter other than intensified workshops conducted by the International Atomic Energy Agency (IAEA) or private companies which can be expensive especially for large groups of students. Currently there are many world-wide projects in routine monitoring and advanced research that employ gamma rays. Some but not an exhaustive list of these topics include neutron activation analysis, naturally occurring radioactivity materials (NORM), nuclear forensics, nuclear security, in-situ gamma ray detection, galactic gamma ray detection, health physics and advanced instrumentation. At the Nuclear Engineering Teaching Laboratory at the University of Texas at Austin, many of our students are involved in an array of research topics that involve gamma ray spectrometry in their Masters of Science theses, PhD dissertations and special topics courses. It was decided to invest the time and effort to develop a course with a strong technical component to complement their research activities. A detailed stand-alone course in gamma ray spectrometry that includes a series lectures in modular form has been developed. As well we have incorporated fourteen advanced animations to better explain some of the fundamental physical processes and experimental set-ups. Six laboratory sessions and multiple homework assignments have also been established. This course is applicable to senior undergraduate students, graduate students, and novice researchers the above mentioned fields in a traditional class/laboratory setting or for intense one to two week workshops. A great deal of effort was undertaken to prepare a stand-alone course in gamma ray spectrometry which includes many of the fundamental aspects as well as the more advanced instrumentation. Animations of gamma ray interactions and experimental set ups were also developed. Six laboratories and six assignments were also conceived. Every topic has its own module thus a 'pick and choose' subset of lectures can be given to different levels of understanding. This course is applicable to senior undergraduate students, graduate students, novice researchers in neutron activation analysis and naturally occurring radioactive material, and for intense one to two week workshops. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Overview of IAEA MODARIA II Program Working Group 1 on Assessment and Decision Making of Existing Exposure Situations for NORM and Nuclear Legacy Sites - 18308

The International Atomic Energy Agency (IAEA) launched the Modelling and Data for Radiological Impact Assessments (MODARIA) II Programme in October. As part of the IAEA effort to enhance the capabilities of its Member States in assessing radiological impacts of radionuclides released to the environment from sites that were not operated in accordance with current standards, and to ensure protection of the public and the environment, the MODARIA II Programme aims to: (1) test the performance of models developed for predicting the transfer of radionuclides in the environment and assessing radiological impacts to the public and the environment; (2) develop and improve models for particular environments and, where appropriate, to agree on data sets that are generally applicable for use in testing environmental transfer models; and (3) provide an international forum for the exchange of experiences, ideas and research information. The Programme will run for 3 years from 2016 to 2019. The Programme comprises seven working groups covering a wide range of topics (https://wwwns.iaea.org/projects/modaria/modaria2.asp?s=8 and l=129). MODARIA II Working Group 1 (WG1) is focused on dose assessment and decision making regarding existing exposure situations due to naturally occurring radioactive material (NORM) and nuclear legacy sites. WG1 was formed as a combination of two MODARIA I WGs: WG1 focused on application of decision-aiding tools in remediation; and WG3 focused on risk assessment for NORM and radioactively contaminated legacy sites (https://wwwns.iaea.org/projects/modaria/default.asp?s=8 and l=129). It was recognized that the decision-making needs will inform the scope of risk assessments, and the risk insights and structured decision analyses will aid in informed decision-making. Therefore, MODARIA II WG1 is focused on developing methods and toolsets for risk-informed decision-making for NORM and nuclear legacy sites, including demonstration of decision-making processes and tools through case studies. MODARIA II WG1 has 91 registered participants from 33 Member States and IAEA (as of November 2017), some 30 of whom are actively engaged in various collaborative research and development activities within WG1. Members of WG1 participated in the First Technical Meeting of MODARIA II, which was held in Vienna, Austria from 31 October to 4 November 2016. The group then held its First Interim Meeting in Brussels, Belgium from 26 to 30 June 2017, which included a field trip to the legacy Tessenderlo Chemie (TCH) Phosphate Processing Site. At this meeting, the TCH Site and the Pridneprovsky Chemical Plant (PChP) in Ukraine were selected for case studies. The Los Alamos National Laboratory (LANL) Material Disposal Area B in the USA and the Beaverlodge Uranium Mill and Mill Site in northern Canada were selected as examples for sharing of good practices and lessons learned in risk-informed decision-making for environmental remediation and land conveyance. At the Second Technical Meeting held in Vienna on 30 October to 3 November 2017, an additional NORM site for tin processing in Brazil was added to the case studies, with another NORM site in Yunnan, China included for consideration at the Second Interim Meeting of WG1. The Second Interim Meeting will be held in in early to mid-May, 2018. The group has also decided to prepare an Interim Report by October 2018 to document the WG1 discussions and analyses for the period of 2016-2018, which will be finalized at the conclusion of MODARIA II in October 2019. Initial assignments have been discussed for IM1 participants to collect data, conduct modelling and analyses, and prepare draft sections for the Interim Report. This paper will provide an overview of the work plans for WG1. It will also highlight some near-term activities that the group is currently working on. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Application of MARSSIM and MARSAME Guidance to Footprint Reduction Projects at a DOE Site (LA-UR-15-28730) - 16216

Department of Energy regulations require that potentially contaminated items and materials being released to the public are monitored and that any residual radioactive contamination does not contribute more than 10 μSv/y (1 mrem/y). In footprint reduction and demolition projects, buildings with potential residual contamination must be carefully and systematically surveyed prior to recycling materials or releasing debris for burial in commercial landfills. Multi-agency guidance is available to assure statistically representative sampling of the items and materials, appropriate measurement quality objectives, and valid statistical approaches for release decisions. Additionally, implementing a cost-effective evaluation program for releases requires working closely with regulators and waste generators and developing a technically sound process to account for naturally occurring radioactive material (NORM) in building materials. Los Alamos National Laboratory has successfully implemented the available guidance for footprint reduction projects to help divert clean, recyclable materials from landfills and limit the possibility of mistakenly disposing of NORM as low level waste. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

NORM in Building Materials: A Case Study in Releasing and Disposing of Building Debris within the DOE System - 18123

In 2013, the Office of Management and Budget issued Memorandum 2013-02, clarifying its 'Freeze the Footprint' policy. Memorandum 2013-02 requires that all federal agencies maintain or reduce their total square footage, within each subsequent year, from a FY2012 baseline. Memorandum 2013-02 also requires that total square footage remain constant with respect to the type/intended use of a building. At Los Alamos National Laboratory (LANL), this means that new construction cannot occur without demolition of equivalent (both in type and square footage) building(s). Since 2013, decommissioning and demolition of aging, unused facilities at LANL has increased. In 2016, the TA16-280 building complex was scheduled for demolition. TA16-280 is a former high explosives (HE) processing facility that consists of six buildings connected to each other via weatherproof walkways. It was constructed in the 1950's and has been subsequently used for HE shipping, receiving, and storage. Interviews with radiation protection staff suggest that some of the buildings within the complex may have been used to store depleted uranium metal parts in a non-dispersible form. It is LANL policy to conduct decommissioning surveys for radioactive materials when building history cannot confirm that a structure is radiologically non-impacted. LANL follows the Multi-Agency Radiation Survey and Assessment of Materials and Equipment (MARSAME) process to develop its surveys and clear structures from radiological control. After clearance, a structure may be dispositioned as non-regulated waste, at a significant cost savings compared to regulated disposition pathways such as low-level waste. MARSAME measurements conducted in the 16-280 complex were elevated compared to reference measurements of surrogate materials, and a majority of the survey units failed to pass indistinguishable from background (IFB), which is LANL's unregulated clearance criteria. Further measurements conducted both in situ and in the laboratory indicated the presence of naturally-occurring thorium in several building materials including: poured concrete, the glaze atop ceramic blast tiles, and the porcelain enamel on the exterior of blast-proof ceiling lamps. Other than naturally-occurring thorium, there were no elevated radionuclide concentrations detected in building materials. It should be noted that there was no history of thorium use in the 16-280 complex, and the material in question was in all cases fixed to and within the building materials in question. Except in certain specific cases, such material is exempt from regulation under the Atomic Energy Act of 1954 [3], as amended, and is therefore exempt from regulation under the Nuclear Regulatory Commission, the Department of Energy, and agreement state regulatory frameworks. Despite this regulatory exemption, disposition of material from the 16-280 complex proved to be challenging, principally because local industrial landfills stipulate 'No radioactive material' in their Waste Acceptance Criteria. This disconnect between what is regulated and what is disposable creates a situation where some DOE sites find it easier to disposition property as Low Level Waste in lieu of pursuing a non-regulated disposition pathway. This presentation will explore the specifics of the 16-280 decommissioning project as well as the implications of the release/disposition disconnect for naturally occurring radioactive material and project planning at LANL. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

A Retrospective Assessment of Correlation between Occupational and Public Radiation Protection Programs Performance Metrics at a FUSRAP Site - 17546

A retrospective assessment of the occupational and environmental radiation protection programs includes the consideration of performance metrics at the qualitative and quantitative level. When key radiation protection (RP) program metrics are tracked over the course of several years, correlations may present themselves. Strong correlations between variables may be considered when establishing or validating baseline RP Program elements (i.e., controls, monitoring regimes, and additional ALARA measures) for the safe excavation and handling of naturally occurring radioactive materials comingled in soil-like wastes at FUSRAP sites. (authors)

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2016

Detection with Enhanced Energy Windowing Phase I Report

This document reviews the progress of Phase I of the Detection with Enhanced Energy Windowing (DEEW) project. The DEEW project is the implementation of software incorporating an algorithm which reviews data generated by radiation portal monitors and utilizes advanced and novel techniques for detecting radiological and fissile material while not alarming on Naturally Occurring Radioactive Material. Independent testing indicated that the Enhanced Energy Windowing algorithm showed promise at reducing the probability of alarm in the stream of commerce compared to existing algorithms and other developmental algorithms, while still maintaining adequate sensitivity to threats. This document contains a brief description of the project, instructions for setting up and running the applications, and guidance to help make reviewing the output files and source code easier.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2017

Initial Modeling of Urban Search Measurements

Detection of illicit nuclear materials in urban environments is difficult due to the large amount of background radiation from naturally occurring radioactive materials (NORM) in the roadways and buildings. Mobile searches suffer from low count rates, so the detection algorithms must be carefully balanced between missing real sources and reporting too many false alarms. The Modeling Urban Scenarios and Experiments (MUSE) project aims to create a virtual testbed for simulation of radiation detection to predict realistic background and threat source detection events so that detection algorithms can be better optimized to find illicit sources. The MUSE project is a collaboration of Oak Ridge National Laboratory (ORNL), Lawrence Berkeley National Laboratory (LBNL), and the Remote Sensing Laboratory (RSL). The project also works with staff at Lawrence Livermore National Laboratory (LLNL) to support the development of the Optimization Planning Tool for Urban Search (OPTUS) software package. The first step in creating a virtual testbed is to determine the level of detail required in the models to match actual measurements. Several measurement campaigns were conducted in 2015 and 2016 at the Fort Indiantown Gap (FTIG) Combined Arms Collective Traming Facility (CACTF). This facility contains a representative urban environment, with a dozen buildings and several streets. Detectors commonly used in search operations - 2 in x 4 in x 16 in NaI(Tl) - were used to measure count rates from background and sources. Measurements with a shielded high-purity germanium detector of the roadways, sidewalks, and building walls were made to determine the concentration of NORM that makes up the bulk of the background radiation. This paper shows some comparisons of modeling simulations to measurements taken during the OPTUS-3 campaign in November 2015. Measurements with and without an 81 {mu}Ci cesium source were made at several points along the center line of the main road. Initial results show good agreement between the measured and simulated spectra above 300 keV. Additional studies to determine the causes of mismatch below 300 keV have been started and will also be discussed.

07 ISOTOPE AND RADIATION SOURCES↗