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All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

H420 Imager Calibration Procedure: Field of View Scan

Gamma-ray imagers with coded apertures have a finite field of view (FOV) within which an image of a source can be generated. A “FOV scan” is a facet of imager calibration procedure that involves collecting specialized data for a range of source locations filling the FOV in order to understand and correct for differences in imager performance. Systematic distortions reveal relative displacements between internal imager components, which can be accounted for in data analysis. The success of this scan requires a stable imager position during the full measurement duration (~hours). This document summarizes the hardware and software tools required to conduct a FOV calibration scan of an H3D H420 Coded Aperture Gamma-Ray Imager.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

SUPPORTING THE INDUSTRY BY DEVELOPING A DESIGN GUIDANCE FOR COMPUTER-BASED PROCEDURES FOR FIELD WORKERS

The paper-based procedures currently used for nearly all activities in the commercial nuclear power industry have a long history of ensuring safe operation of the plants. However, there is potential to greatly increase efficiency and safety by improving how the human interacts with the procedures, which can be achieved through the use of computer-based procedures (CBPs). A CBP system offers a vast variety of improvements, such as context driven job aids, integrated human performance tools and dynamic step presentation. As a step toward the goal of improving procedure use performance, the U.S. Department of Energy Light Water Reactor Sustainability Program researchers, together with the nuclear industry, have been investigating the possibility and feasibility of replacing current paper-based procedures with CBPs. The main purpose of the CBP research conducted at the Idaho National Laboratory was to provide design guidance to the nuclear industry to be used by both utilities and vendors. After studying existing design guidance for CBP systems, the researchers concluded that the majority of the existing guidance is intended for control room CBP systems, and does not necessarily address the challenges of designing CBP systems for instructions carried out in the field. Further, the guidance is often presented on a high level, which leaves the designer to interpret what is meant by the guidance and how to specifically implement it. The authors developed a design guidance to provide guidance specifically tailored to instructions that are carried out in the field based.

47 OTHER INSTRUMENTATION↗
DOE OSTI2016

Computer Based Procedures for Field Workers - FY16 Research Activities

The Computer-Based Procedure (CBP) research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which provides the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. One of the primary missions of the LWRS program is to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. One area that could yield tremendous savings in increased efficiency and safety is in improving procedure use. A CBP provides the opportunity to incorporate context-driven job aids, such as drawings, photos, and just-in-time training. The presentation of information in CBPs can be much more flexible and tailored to the task, actual plant condition, and operation mode. The dynamic presentation of the procedure will guide the user down the path of relevant steps, thus minimizing time spent by the field worker to evaluate plant conditions and decisions related to the applicability of each step. This dynamic presentation of the procedure also minimizes the risk of conducting steps out of order and/or incorrectly assessed applicability of steps. This report provides a summary of the main research activities conducted in the Computer-Based Procedures for Field Workers effort since 2012. The main focus of the report is on the research activities conducted in fiscal year 2016. The activities discussed are the Nuclear Electronic Work Packages – Enterprise Requirements initiative, the development of a design guidance for CBPs (which compiles all insights gained through the years of CBP research), the facilitation of vendor studies at the Idaho National Laboratory (INL) Advanced Test Reactor (ATR), a pilot study for how to enhance the plant design modification work process, the collection of feedback from a field evaluation study at Plant Vogtle, and path forward to commercialize INL’s CBP system.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

Design Guidance for Computer-Based Procedures for Field Workers

Nearly all activities that involve human interaction with nuclear power plant systems are guided by procedures, instructions, or checklists. Paper-based procedures (PBPs) currently used by most utilities have a demonstrated history of ensuring safety; however, improving procedure use could yield significant savings in increased efficiency, as well as improved safety through human performance gains. The nuclear industry is constantly trying to find ways to decrease human error rates, especially human error rates associated with procedure use. As a step toward the goal of improving field workers’ procedure use and adherence and hence improve human performance and overall system reliability, the U.S. Department of Energy Light Water Reactor Sustainability (LWRS) Program researchers, together with the nuclear industry, have been investigating the possibility and feasibility of replacing current paper-based procedures with computer-based procedures (CBPs). PBPs have ensured safe operation of plants for decades, but limitations in paper-based systems do not allow them to reach the full potential for procedures to prevent human errors. The environment in a nuclear power plant is constantly changing, depending on current plant status and operating mode. PBPs, which are static by nature, are being applied to a constantly changing context. This constraint often results in PBPs that are written in a manner that is intended to cover many potential operating scenarios. Hence, the procedure layout forces the operator to search through a large amount of irrelevant information to locate the pieces of information relevant for the task and situation at hand, which has potential consequences of taking up valuable time when operators must be responding to the situation, and potentially leading operators down an incorrect response path. Other challenges related to use of PBPs are management of multiple procedures, place-keeping, finding the correct procedure for a task, and relying on other sources of additional information to ensure a functional and accurate understanding of the current plant status (Converse, 1995; Fink, Killian, Hanes, and Naser, 2009; Le Blanc, Oxstrand, and Waicosky, 2012). This report provides design guidance to be used when designing the human-system interaction and the design of the graphical user interface for a CBP system. The guidance is based on human factors research related to the design and usability of CBPs conducted by Idaho National Laboratory, 2012 - 2016.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Supporting the industry by developing a design guidance for computer-based procedures for field workers - 274

The paper-based procedures currently used for nearly all activities in the commercial nuclear power industry have a long history of ensuring safe operation of the plants. However, there is potential to greatly increase efficiency and safety by improving how the human interacts with the procedures, which can be achieved through the use of computer-based procedures (CBPs). A CBP system offers a vast variety of improvements, such as context driven job aids, integrated human performance tools and dynamic step presentation. As a step toward the goal of improving procedure use performance, the U.S. Department of Energy Light Water Reactor Sustainability Program researchers, together with the nuclear industry, have been investigating the feasibility of replacing current paper-based procedures with CBPs. The main purpose of the CBP research for nuclear field workers conducted at the Idaho National Laboratory was to provide design guidance to the nuclear industry to be used by both utilities and vendors. After studying existing design guidance for CBP systems, the researchers concluded that the majority of the existing guidance is intended for control room CBP systems, and does not necessarily address the challenges of designing CBP systems for instructions carried out in the field. Further, the guidance is often presented on a high level, which leaves the designer to interpret what is meant by the guidance and how to specifically implement it. The authors developed a design guidance to provide guidance specifically tailored to instructions that are carried out in the field based. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2014

Computer-based procedure for field activities: Results from three evaluations at nuclear power plants

Nearly all activities that involve human interaction with the systems of a nuclear power plant are guided by procedures. The paper-based procedures (PBPs) currently used by industry have a demonstrated history of ensuring safety; however, improving procedure use could yield tremendous savings in increased efficiency and safety. One potential way to improve procedure-based activities is through the use of computer-based procedures (CBPs). Computer-based procedures provide the opportunity to incorporate context driven job aids, such as drawings, photos, just-in-time training, etc into CBP system. One obvious advantage of this capability is reducing the time spent tracking down the applicable documentation. Additionally, human performance tools can be integrated in the CBP system in such way that helps the worker focus on the task rather than the tools. Some tools can be completely incorporated into the CBP system, such as pre-job briefs, placekeeping, correct component verification, and peer checks. Other tools can be partly integrated in a fashion that reduces the time and labor required, such as concurrent and independent verification. Another benefit of CBPs compared to PBPs is dynamic procedure presentation. PBPs are static documents which limits the degree to which the information presented can be tailored to the task and conditions when the procedure is executed. The CBP system could be configured to display only the relevant steps based on operating mode, plant status, and the task at hand. A dynamic presentation of the procedure (also known as context-sensitive procedures) will guide the user down the path of relevant steps based on the current conditions. This feature will reduce the user’s workload and inherently reduce the risk of incorrectly marking a step as not applicable and the risk of incorrectly performing a step that should be marked as not applicable. As part of the Department of Energy’s (DOE) Light Water Reactors Sustainability Program, researchers at Idaho National Laboratory (INL) along with partners from the nuclear industry have been investigating the design requirements for computer-based work instructions (including operations procedures, work orders, maintenance procedures, etc.) to increase efficiency, safety, and cost competitiveness of existing light water reactors.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2015

The Next Step in Deployment of Computer Based Procedures For Field Workers: Insights And Results From Field Evaluations at Nuclear Power Plants

The paper-based procedures currently used for nearly all activities in the commercial nuclear power industry have a long history of ensuring safe operation of the plants. However, there is potential to greatly increase efficiency and safety by improving how the human operator interacts with the procedures. One way to achieve these improvements is through the use of computer-based procedures (CBPs). A CBP system offers a vast variety of improvements, such as context driven job aids, integrated human performance tools (e.g., placekeeping, correct component verification, etc.), and dynamic step presentation. The latter means that the CBP system could only display relevant steps based on operating mode, plant status, and the task at hand. A dynamic presentation of the procedure (also known as context-sensitive procedures) will guide the operator down the path of relevant steps based on the current conditions. This feature will reduce the operator’s workload and inherently reduce the risk of incorrectly marking a step as not applicable and the risk of incorrectly performing a step that should be marked as not applicable. The research team at the Idaho National Laboratory has developed a prototype CBP system for field workers, which has been evaluated from a human factors and usability perspective in four laboratory studies. Based on the results from each study revisions were made to the CBP system. However, a crucial step to get the end users' (e.g., auxiliary operators, maintenance technicians, etc.) acceptance is to put the system in their hands and let them use it as a part of their everyday work activities. In the spring 2014 the first field evaluation of the INL CBP system was conducted at a nuclear power plant. Auxiliary operators conduct a functional test of one out of three backup air compressors each week. During the field evaluation activity, one auxiliary operator conducted the test with the paper-based procedure while a second auxiliary operator followed along with the computer-based procedure. After each conducted functional test the operators were asked a series of questions designed to provide feedback on the feasibility to use a CBP system in the plant and the general user experience of the CBP system. This paper will describe the field evaluation and its results in detail. For example, the result shows that the context driven job aids and the incorporated human performance tools are much liked by the auxiliary operators. The paper will describe and present initial findings from a second field evaluation conducted at second nuclear utility. For this field evaluation a preventive maintenance work order for the HVAC system was used. In addition, there will be a description of the method and objective of two field evaluations planned to be conducted late 2014 or early 2015.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2014

Light Water Reactor Sustainability Program: Computer-Based Procedures for Field Activities: Results from Three Evaluations at Nuclear Power Plants

The Computer-Based Procedure (CBP) research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by Department of Energy (DOE) and performed in close collaboration with industry R&D programs that provides the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. One of the primary missions of the LWRS program is to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. One area that could yield tremendous savings in increased efficiency and safety is in improving procedure use. Nearly all activities in the nuclear power industry are guided by procedures, which today are printed and executed on paper. This paper-based procedure process has proven to ensure safety; however, there are improvements to be gained. Due to its inherent dynamic nature, a CBP provides the opportunity to incorporate context driven job aids, such as drawings, photos, and just-in-time training. Compared to the static state of paper-based procedures (PBPs), the presentation of information in CBPs can be much more flexible and tailored to the task, actual plant condition, and operation mode. The dynamic presentation of the procedure will guide the user down the path of relevant steps, thus minimizing time spent by the field worker to evaluate plant conditions and decisions related to the applicability of each step. This dynamic presentation of the procedure also minimizes the risk of conducting steps out of order and/or incorrectly assessed applicability of steps.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2014

Computer-Based Procedures for Field Workers - Identified Benefits

The Idaho National Laboratory (INL) computer-based procedure (CBP) research team is exploring how best to design a CBP system that will deliver the intended benefits of increased efficiency and improved human performance. It is important to note that no “off-the-shelf” technology exists for the type of CBP system that is investigated and developed by the INL researchers. As more technology is integrated into the procedure process the importance of an appropriate and methodological approach to the design of the procedure system increases. Technological advancements offer great opportunities for efficiency and safety gains, however if the system is not designed correctly there is a large risk of unintentionally introducing new opportunities for human errors. The INL research team is breaking new ground in the area of CBPs with the prototype they have developed. Current electronic procedure systems are most commonly electronic versions of the paper-based procedures with hyperlinks to other procedures, limited user input functionality, and the ability to mark steps completed. These systems do not fully exploit the advantages digital technology. It is a part of the INL researchers’ role to develop and validate new CBP technologies that greatly increase the benefits of a CBP system to the nuclear industry.

47 OTHER INSTRUMENTATION↗
DOE OSTI2019

Module OT PNM Field Demonstration Test Procedure

This document will detail a field demonstration test procedure for the Module OT device developed for the joint NREL-SNL DOE CEDS project titled "Modular Security Apparatus for Managing Distributed Cryptography for Command & Control Messages on Operational Technology (OT) Networks." The aim of this document is to create the testing and evaluation procedure for field demonstration of the device; this includes primarily functional testing and implementation testing at Public Service Company of New Mexico's (PNM's) Prosperity solar site environment. Specifically, the Module OT devices will be integrated into the Prosperity solar site system; traffic will be encrypted between several points of interest at the site (e.g., inverter micrologger and switch). The tests described in this document will be performed to assess the impact and effectiveness of the encryption capabilities provided by the Module OT device.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2017

Project 57 Air Monitoring Report: January 1 through December 31, 2015

On April 24, 1957, the Atomic Energy Commission (AEC, now the Department of Energy [DOE]) conducted the Project 57 safety experiment in western Emigrant Valley north east of the Nevada National Security Site (NNSS, formerly the Nevada Test Site) on lands withdrawn by the Department of Defense (DOD) for the Nevada Test and Training Range (NTTR). The test was undertaken to develop (1) a means of estimating plutonium distribution resulting from a non-nuclear detonation; (2) biomedical evaluation techniques for use in plutonium-laden environments; (3) methods of surface decontamination; and (4) instruments and field procedures for prompt estimation of alpha contamination (Shreve, 1958). Although the test did not result in the fission of nuclear materials, it did disseminate plutonium across the land surface. Following the experiment, the AEC fenced the contaminated area and returned control of the surrounding land to the DOD. Various radiological surveys were performed in the area and in 2007, the DOE expanded the demarked Contamination Area by posting signs 200 to 400 feet (60 to 120 meters) outside of the original fence.

(1)↗
DOE OSTI2020

Charged Wellbore Casing Controlled Source Electromagnetics (CWC-CSEM) for Reservoir Imaging and Monitoring (Final report)

This project addresses the needs of the U.S. Department of Energy (DOE) to develop advanced monitoring technologies and protocols to track the fate of subsurface carbon dioxide (CO2) plumes for carbon storage. Specifically, the project seeks to develop and test a unique and novel system of technologies consisting of electromagnetic data acquisition, coupled multiphysics imaging, and reservoir model enhancement to understand the migration and long-term distribution of CO2 in the subsurface. The overarching objective is to develop an integrated approach for long term monitoring of carbon storage. The two main components of the project include the methodology development and the test of the method at a field site. The methodology component consists of 1) developing the field procedure and protocol for collecting time-lapse controlled-source electromagnetic (CSEM) data with source electric current injected into the subsurface through wellbore casings; 2) building of background 3D electrical conductivity utilizing multiple sources of data such as supplemental surface transient EM (TEM) surveys, well-logs, and seismic structural information, for enhancing CSEM signal from reservoir depths; and 3) coupled multiphysics simulations and inversion of CSEM data constrained by production data and by structural information from seismic imaging of the reservoir and overlying formations. The testing component used the field site of Bell Creek Oil Field, which served both as a field laboratory for the method development as well as a test site to evaluate the CSEM signal strengths and the methodology developed in this research project. We have accomplished all the proposed tasks and developed the methodology as planned. These include the procedure for time-lapse CSEM data acquisition, data processing techniques, integration with 3D conductivity model building, fast reservoir simulation for history matching using machine learning, and interpreting CSEM data with coupling to the reservoir modeling. Collectively, the outcome of these tasks form a coherent workflow that can be applied to monitor dedicated carbon storage in saline reservoirs. The testing component evaluated the applicability and limitations of the method, and concluded that the method would be ideal for monitoring dedicated carbon storage sites utilizing saline reservoirs.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Seniority number description of potential energy surfaces: Symmetric dissociation of water, N{sub 2}, C{sub 2}, and Be{sub 2}

The present study further explores the concept of the seniority number (Ω) by examining different configuration interaction (CI) truncation strategies in generating compact wave functions in a systematic way. While the role of Ω in addressing static (strong) correlation problem has been addressed in numerous previous studies, the usefulness of seniority number in describing weak (dynamic) correlation has not been investigated in a systematic way. Thus, the overall objective in the present work is to investigate the role of Ω in addressing also dynamic electron correlation in addition to the static correlation. Two systematic CI truncation strategies are compared beyond minimal basis sets and full valence active spaces. One approach is based on the seniority number (defined as the total number of singly occupied orbitals in a determinant) and another is based on an excitation-level limitation. In addition, molecular orbitals are energy-optimized using multiconfigurational-self-consistent-field procedure for all these wave functions. The test cases include the symmetric dissociation of water (6-31G), N{sub 2} (6-31G), C{sub 2} (6-31G), and Be{sub 2} (cc-pVTZ). We find that the potential energy profile for H{sub 2}O dissociation can be reasonably well described using only the Ω = 0 sector of the CI wave function. For the Be{sub 2} case, we show that the full CI potential energy curve (cc-pVTZ) is almost exactly reproduced using either Ω-based (including configurations having up to Ω = 2 in the virtual-orbital-space) or excitation-based (up to single-plus-double-substitutions) selection methods, both out of a full-valence-reference function. Finally, in dissociation cases of N{sub 2} and C{sub 2}, we shall also consider novel hybrid wave functions obtained by a union of a set of CI configurations representing the full valence space and a set of CI configurations where seniority-number restriction is imposed for a complete set (full-valence-space and virtual) of correlated molecular orbitals, simultaneously. We discuss the usefulness of the seniority number concept in addressing both static and dynamic electron correlation problems along dissociation paths.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2014

Stability conditions for exact-exchange Kohn-Sham methods and their relation to correlation energies from the adiabatic-connection fluctuation-dissipation theorem

The occurrence of instabilities, in particular singlet-triplet and singlet-singlet instabilities, in the exact-exchange (EXX) Kohn-Sham method is investigated. Hessian matrices of the EXX electronic energy with respect to the expansion coefficients of the EXX effective Kohn-Sham potential in an auxiliary basis set are derived. The eigenvalues of these Hessian matrices determine whether or not instabilities are present. Similar as in the corresponding Hartree-Fock case instabilities in the EXX method are related to symmetry breaking of the Hamiltonian operator for the EXX orbitals. In the EXX methods symmetry breaking can easily be visualized by displaying the local multiplicative exchange potential. Examples (N{sub 2}, O{sub 2}, and the polyyne C{sub 10}H{sub 2}) for instabilities and symmetry breaking are discussed. The relation of the stability conditions for EXX methods to approaches calculating the Kohn-Sham correlation energy via the adiabatic-connection fluctuation-dissipation (ACFD) theorem is discussed. The existence or nonexistence of singlet-singlet instabilities in an EXX calculation is shown to indicate whether or not the frequency-integration in the evaluation of the correlation energy is singular in the EXX-ACFD method. This method calculates the Kohn-Sham correlation energy through the ACFD theorem theorem employing besides the Coulomb kernel also the full frequency-dependent exchange kernel and yields highly accurate electronic energies. For the case of singular frequency-integrands in the EXX-ACFD method a regularization is suggested. Finally, we present examples of molecular systems for which the self-consistent field procedure of the EXX as well as the Hartree-Fock method can converge to more than one local minimum depending on the initial conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Full-potential KKR within the removed-sphere method: A practical and accurate solution to the Poisson equation

Here an efficient and accurate generalization of the removed-sphere method (RSM) to solve the Poisson equation for total charge density in a solid with space-filling convex Voronoi polyhedra (VPs) and any symmetry is presented. The generalized RSM avoids the use of multipoles and VP shape functions for cellular integrals, which have associated ill-convergent large, double-internal L sums in spherical-harmonic expansions, so that fast convergence in single-L sums is reached. Our RSM adopts full Ewald formulation to work for all configurations or when symmetry breaking occurs, such as for atomic displacements or elastic constant calculations. The structure-dependent coefficients A L that define RSM can be calculated once for a fixed structure and speed up the whole self-consistent-field procedure. The accuracy and rapid convergence properties are confirmed using two analytic models, including the Coulomb potential and energy. We then implement the full-potential RSM using the Green's function Korringa-Kohn-Rostoker (KKR) method for real applications and compare the results with other first-principle methods and experimental data, showing that they are equally as accurate.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2013

Evaluation of Revised Computer-Based Procedure System Prototype

The nuclear power industry is very procedure driven, i.e. almost all activities that take place at a nuclear power plant are conducted by following procedures. The paper-based procedures (PBPs) currently used by the industry do a good job at keeping the industry safe. However, these procedures are most often paired with methods and tools put in place to anticipate, prevent, and catch errors related to hands-on work. These tools are commonly called human performance tools. The drawback with the current implementation of these tools is that the task of performing one procedure becomes time and labor intensive. For example, concurrent and independent verification of procedure steps are required at times, which essentially means that at least two people have to be actively involved in the task. Even though the current use of PBPs and human performance tools are keeping the industry safe, there is room for improvement. The industry could potentially increase their efficiency and safety by replacing their existing PBPs with CBPs. If implemented correctly, the CBP system could reduce the time and focus spent on using the human performance tools. Some of the tools can be completely incorporated in the CBP system in a manner that the performer does not think about the fact that these tools are being used. Examples of these tools are procedure use and adherence, placekeeping, and peer checks. Other tools can be partly integrated in a fashion that reduce the time and labor they require, such as concurrent and independent verification. The incorporation of advanced technology, such as CBP systems, may help to manage the effects of aging systems, structures, and components. The introduction of advanced technology may also make the existing LWR fleet more attractive to the future workforce, which will be of importance when the future workforce will chose between existing fleet and the newly built nuclear power plants.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2016

Project 57 Air Monitoring Report: October 1, 2013, through December 31, 2014

On April 24, 1957, the Atomic Energy Commission (AEC, now the Department of Energy [DOE]) conducted the Project 57 safety experiment in western Emigrant Valley north east of the Nevada National Security Site (NNSS, formerly the Nevada Test Site) on lands withdrawn by the Department of Defense (DoD) for the Nevada Test and Training Range (NTTR). The test was undertaken to develop (1) a means of estimating plutonium distribution resulting from a nonnuclear detonation; (2) biomedical evaluation techniques for use in plutonium-laden environments; (3) methods of surface decontamination; and (4) instruments and field procedures for prompt estimation of alpha contamination (Shreve, 1958). Although the test did not result in the fission of nuclear materials, it did disseminate plutonium across the land surface. Following the experiment, the AEC fenced the contaminated area and returned control of the surrounding land to the DoD. Various radiological surveys have been performed in the area and in 2007, the DOE expanded the demarked contamination area by posting signs 200 to 400 feet (60 to 120 meters) outside of the original fence. Plutonium in soil is thought to attach preferentially to smaller particles. Therefore, redistribution of soil particulates by wind (dust) is the mechanism most likely to transport plutonium beyond the boundary of the Project 57 contamination area. In 2011, DRI installed two instrumentation towers to measure radiological, meteorological, and dust conditions. The monitoring activity was implemented to determine if radionuclide contamination was detectable in samples of airborne dust and characterize meteorological and environmental parameters that influence dust transport. Collected data also permits comparison of radiological conditions at the Project 57 monitoring stations to conditions observed at Community Environmental Monitoring Program (CEMP) stations around the NTTR. Biweekly samples of airborne particulates are submitted for laboratory assessment of gross alpha and gross beta radioactivity and for determination of gamma-emitting radionuclides. Annual average gross alpha values at the Project 57 monitoring stations are in the same range as the highest two values reported for the CEMP stations surrounding the NTTR. Annual average gross beta values at the Project 57 monitoring stations are slightly higher than the lowest value reported for the CEMP stations surrounding the NTTR. Gamma spectroscopy analyses on samples collected from the Project 57 stations identified only naturally occurring radionuclides. No manmade radionuclides were detected. Thermoluminescent dosimeters (TLDs) indicated that the average annual radioactivity dose at the monitoring stations is higher than the dose determined at surrounding CEMP stations but approximately half of the estimated national average dose received by the general public as a result of exposure to natural sources. The TLDs at the Project 57 monitoring stations are exposed to both natural sources (terrestrial and cosmic) and radioactive releases from the Project 57 contamination area. These comparisons show that the gross alpha, gross beta, and gamma spectroscopy levels at the Project 57 monitoring stations are similar to levels observed at the CEMP stations but that the average annual dose rate is higher than at the CEMP stations. Winds in excess of approximately 15 mph begin to generate dust movement by saltation (migration of sand at the ground surface) or direct suspension in the air. Saltated sand, PM10 (inhalable) dust, and PM2.5 (fine particulate dust) exhibit an approximately exponential increase with increasing wind speed. The greatest concentrations of dust occur for winds exceeding 20 mph. During the reporting period, winds in excess of 20 mph occurred approximately 1.6 percent of the time. Preliminary assessment of individual wind events suggests that dust generation is highly variable likely because of the influence of other meteorological and environmental parameters. Although winds sufficient to generate significant amounts of dust occur at the Project 57 site, they are infrequent and of short duration. Additionally, the potential for wind transport of dust is dependent on other parameters whose influence have not yet been assessed.

54 ENVIRONMENTAL SCIENCES↗