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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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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

CLARA: A Contemporary Approach to Physics Data Processing

In traditional physics data processing (PDP) systems, data location is static and is accessed by analysis applications. In comparison, CLARA (CLAS12 Reconstruction and Analysis framework) is an environment where data processing algorithms filter continuously flowing data. In CLARA's domain of loosely coupled services, data is not stored, but rather flows from one service to another, mutating constantly along the way. Agents, performing event processing, can then subscribe to particular data/events at any stage of the data transformation, and make intricate decisions (e.g. particle ID) by correlating events from multiple, parallel data streams and/or services. This paper presents a PDP application development framework based on service oriented and event driven architectures. This system allows users to design (Java, C++, and Python languages are supported) and deploy data processing services, as well as dynamically compose PDP applications using available services. The PDP service bus provides a layer on top of a distributed pub-sub middleware implementation, which allows complex service composition and integration without writing code. Examples of service creation and deployment, along with the CLAS12 track reconstruction application design will be presented.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2013

Numerical modeling of multi-GeV laser wakefield electron acceleration inside a dielectric capillary tube

Numerical modeling of laser wakefield electron acceleration inside a gas filled dielectric capillary tube is presented. Guiding of a short pulse laser inside a dielectric capillary tube over a long distance (∼1 m) and acceleration of an externally injected electron bunch to ultra-relativistic energies (∼5-10 GeV) are demonstrated in the quasi-linear regime of laser wakefield acceleration. Two dimensional axisymmetric simulations were performed with the code WAKE-EP (Extended Performances), which allows computationally efficient simulations of such long scale plasma. The code is an upgrade of the quasi-static particle code, WAKE [P. Mora and T. M. Antonsen, Jr., Phys. Plasmas 4, 217 (1997)], to simulate the acceleration of an externally injected electron bunch (including beam loading effect) and propagation of the laser beam inside a dielectric capillary. The influence of the transverse electric field of the plasma wake on the radial loss of the accelerated electrons to the dielectric wall is investigated. The stable acceleration of electrons to multi-GeV energy with a non-resonant laser pulse with a large spot-size is demonstrated.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2011

Salinas : theory manual.

Salinas provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of structural systems. This manual describes the theory behind many of the constructs in Salinas. For a more detailed description of how to use Salinas, we refer the reader to Salinas, User's Notes. Many of the constructs in Salinas are pulled directly from published material. Where possible, these materials are referenced herein. However, certain functions in Salinas are specific to our implementation. We try to be far more complete in those areas. The theory manual was developed from several sources including general notes, a programmer notes manual, the user's notes and of course the material in the open literature.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2012

DECOMMISSIONING AND ENVRIONMENTAL CLEANUP OF SMALL ARMS TRAINING FACILITY

USDOE performed a (CERCLA) non-time critical removal (NTCR) action at the Small Arms Training Area (SATA) Site Evaluation Area (SEA) located at the Savannah River Site (SRS), in Aiken, South Carolina. From 1951 to May 2010, the SATA was used as a small weapons practice and qualifying firing range. The SATA consisted of 870.1 ha (2,150 ac) of woodlands and open field, of which approximately 2.9 ha (7.3 ac) were used as a firing range. The SATA facility was comprised of three small arms ranges (one static and two interactive), storage buildings for supplies, a weapons cleaning building, and a control building. Additionally, a 113- m (370-ft) long earthen berm was used as a target backstop during live-fire exercises. The berm soils accumulated a large amount of spent lead bullets in the berm face during the facilities 59- years of operation. The accumulation of lead was such that soil concentrations exceeded the U.S. Environmental Protection Agency (USEPA) residential and industrial worker regional screening levels (RSLs). The RSL threshold values are based on standardized exposure scenarios that estimate contaminant concentrations in soil that the USEPA considers protective of humans over a lifetime. For the SATA facility, lead was present in soil at concentrations that exceed both the current residential (400 mg/kg) and industrial (800 mg/kg) RSLs. In addition, the concentration of lead in the soil exceeded the Toxicity Characteristic Leaching Procedure (TCLP) (40 Code of Federal Regulations [CFR] 261.24) regulatory limit. The TCLP analysis simulates landfill conditions and is designed to determine the mobility of contaminants in waste. In addition, a principal threat source material (PTSM) evaluation, human health risk assessment (HHRA), and contaminant migration (CM) analysis were conducted to evaluate soil contamination at the SATA SEA. This evaluation determined that there were no contaminants present that constitute PTSM and the CM analysis revealed that no constituents posed a migration risk to groundwater. The NTCR action involved removal of approximately 12,092 m3 (15,816 yd3) of spent bullets and lead-impacted soil and off-site disposal. The removal action included soils from the berm area, a fill area that received scraped soils from the berm, and soil from a drainage ditch located on the edge of the berm area. Also included in the removal action was a mixture of soil, concrete, and asphalt from the other three range areas. Under this action, 11,796 m3 (15,429 yd3) of hazardous waste and impacted soil were removed from the SATA and transported to a permitted hazardous waste disposal facility (Lone Mountain Facility in Oklahoma) and 296 m3 (387 yd3) of nonhazardous waste (primarily concrete debris) were removed and transported to a local solid waste landfill for disposal. During the excavation process, the extent was continuously assessed through the use of a hand-held, field-portable X-ray fluorescence unit with results verified using confirmation sampling with certified laboratory analysis. Following the completion of the excavation and confirmation sampling, final contouring, grading, and establishment of vegetative cover was performed to stabilize the affected areas. The NTCR action began on August 17, 2010, and mechanical completion was achieved on April 27, 2011. The selected removal action met the removal action objectives (RAOs), is protective of human health and the environment both in the short- and long-term, was successful in removing potential ecological risks, and is protective of surface water and groundwater. Furthermore, the selected NTCR action met residential cleanup goals and resulted in the release of the SEA from restricted use contributing to the overall footprint reduction at SRS.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Decommissioning and Environmental Cleanup of a Small Arms Training Facility - 13225

US DOE performed a (CERCLA) non-time critical removal (NTCR) action at the Small Arms Training Area (SATA) Site Evaluation Area (SEA) located at the Savannah River Site (SRS), in Aiken, South Carolina. From 1951 to May 2010, the SATA was used as a small weapons practice and qualifying firing range. The SATA consisted of 870.1 ha (2,150 ac) of woodlands and open field, of which approximately 2.9 ha (7.3 ac) were used as a firing range. The SATA facility was comprised of three small arms ranges (one static and two interactive), storage buildings for supplies, a weapons cleaning building, and a control building. Additionally, a 113- m (370-ft) long earthen berm was used as a target backstop during live-fire exercises. The berm soils accumulated a large amount of spent lead bullets in the berm face during the facilities 59- years of operation. The accumulation of lead was such that soil concentrations exceeded the U.S. Environmental Protection Agency (USEPA) residential and industrial worker regional screening levels (RSLs). The RSL threshold values are based on standardized exposure scenarios that estimate contaminant concentrations in soil that the USEPA considers protective of humans over a lifetime. For the SATA facility, lead was present in soil at concentrations that exceed both the current residential (400 mg/kg) and industrial (800 mg/kg) RSLs. In addition, the concentration of lead in the soil exceeded the Toxicity Characteristic Leaching Procedure (TCLP) (40 Code of Federal Regulations [CFR] 261.24) regulatory limit. The TCLP analysis simulates landfill conditions and is designed to determine the mobility of contaminants in waste. In addition, a principal threat source material (PTSM) evaluation, human health risk assessment (HHRA), and contaminant migration (CM) analysis were conducted to evaluate soil contamination at the SATA SEA. This evaluation determined that there were no contaminants present that constitute PTSM and the CM analysis revealed that no constituents posed a migration risk to groundwater. The NTCR action involved removal of approximately 12,092 m{sup 3} (15,816 yd{sup 3}) of spent bullets and lead-impacted soil and off-site disposal. The removal action included soils from the berm area, a fill area that received scraped soils from the berm, and soil from a drainage ditch located on the edge of the berm area. Also included in the removal action was a mixture of soil, concrete, and asphalt from the other three range areas. Under this action, 11,796 m{sup 3} (15,429 yd{sup 3}) of hazardous waste and impacted soil were removed from the SATA and transported to a permitted hazardous waste disposal facility (Lone Mountain Facility in Oklahoma) and 296 m{sup 3} (387 yd{sup 3}) of nonhazardous waste (primarily concrete debris) were removed and transported to a local solid waste landfill for disposal. During the excavation process, the extent was continuously assessed through the use of a hand-held, field-portable X-ray fluorescence unit with results verified using confirmation sampling with certified laboratory analysis. Following the completion of the excavation and confirmation sampling, final contouring, grading, and establishment of vegetative cover was performed to stabilize the affected areas. The NTCR action began on August 17, 2010, and mechanical completion was achieved on April 27, 2011. The selected removal action met the removal action objectives (RAOs), is protective of human health and the environment both in the short- and long-term, was successful in removing potential ecological risks, and is protective of surface water and groundwater. Furthermore, the selected NTCR action met residential cleanup goals and resulted in the release of the SEA from restricted use contributing to the overall footprint reduction at SRS. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Performance Analysis of Speculative Parallel Adaptive Local Timestepping for Conservation Laws

Stable simulation of conservation laws, such as those used to model fluid dynamics and plasma physics applications, requires the satisfaction of the so-called Courant-Friedrichs-Lewy condition. By allowing regions of the mesh to advance with different timesteps that locally satisfy this stability constraint, significant work reduction can be attained when compared to a time integration scheme using a single timestep size. However, parallelizing this algorithm presents considerable difficulty. Since the stability condition depends on the state of the system, dependencies become dynamic and potentially non-local. In this article, we present an adaptive local timestepping algorithm using an optimistic (Timewarp-based) parallel discrete event simulation. We introduce waiting heuristics to limit misspeculation and a semi-static load balancing scheme to eliminate load imbalance as parts of the mesh require finer or coarser timesteps. Last, we outline an interface for separating the physics of the specific conservation law from the temporal integration allowing for productive adoption of our proposed algorithm. We present a misspeculation study for three conservation laws, demonstrating both the productivity of the local timestepping API, for which 74% of the lines of code are reused across different conservation laws, and the robustness of the waiting heuristics—at most 1.5% of element updates are rolled back. Our performance studies demonstrate up to a 2.8× speedup versus a baseline unoptimized local timestepping approach, a 4x improvement in per-node throughput compared to an MPI parallelization of synchronous timestepping, and scalability up to 3,072 cores on NERSC’s Cori Haswell partition.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2026

Assessing plasma face component thermal response to rotating 3D magnetic fields for SPARC tokamak

Thermal response simulations of plasma-facing components (PFCs) in the SPARC tokamak, performed with the HEAT code, show that three-dimensional (3D) heat loads resulting from stationary n=1 perturbations require highly radiative scenarios, with up to 95% of the power crossing the separatrix (P SOL ) being radiated, to maintain PFC temperatures within acceptable operational limits, whereas the application of slowly rotating 3D fields substantially reduces the thermal loads. The HEAT module, developed to predict heat loads from non-axisymmetric plasmas, is extended to model time-dependent heat flux patterns generated by rotating 3D fields, and a comprehensive thermal analysis is performed on PFCs subjected to both the maximum and minimum power loads, as well as to rotating heat flux distributions, to evaluate the temperature evolution for varying perturbation amplitudes and rotation frequencies. The extension of this analysis to 3D fields with toroidal mode number n=2 shows that this configuration leads to weaker localized heat flux peaks relative to the n=1 case, enabling safe operation with less than 80% of the power radiated when static 3D fields of low amplitude are applied, while using slowly rotating fields at higher amplitudes. These results indicate that n=2 perturbations are generally less detrimental to divertor power exhaust, emphasizing the strong dependence of divertor power exhaust on the characteristics of the applied 3D fields.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2015

CMB and BAO constraints for an induced gravity dark energy model with a quartic potential

We study the predictions for structure formation in an induced gravity dark energy model with a quartic potential. By developing a dedicated Einstein-Boltzmann code, we study self-consistently the dynamics of homogeneous cosmology and of linear perturbations without using any parametrization. By evolving linear perturbations with initial conditions in the radiation era, we accurately recover the quasi-static analytic approximation in the matter dominated era. We use PLANCK 2013 data and a compilation of baryonic acoustic oscillation (BAO) data to constrain the coupling γ to the Ricci curvature and the other cosmological parameters. By connecting the gravitational constant in the Einstein equation to the one measured in a Cavendish-like experiment, we find γ < 0.0012 at 95% CL with PLANCK 2013 and BAO data. This is the tightest cosmological constraint on γ and on the corresponding derived post-Newtonian parameters. Because of a degeneracy between γ and the Hubble constant H{sub 0}, we show how larger values for γ are allowed, but not preferred at a significant statistical level, when local measurements of H{sub 0} are combined in the analysis with PLANCK 2013 data.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

RISK MONITORING CAPABILITES FROM DYNAMIC PRA DATA

Risk Monitors (RMs) are software tools that are employed in nuclear power plants to monitor the safety properties of the plant itself during operation. These safety properties are generated using classical PRA methods which are typically based on static Boolean structures such as Fault-Trees (FTs) and Event-Trees (ETs). The outcomes of these methods are Core Damage Frequency (CDF) and risk importance values of plant components (e.g., valves and pumps). Examples of Risk Importance Measures (RIMs) commonly used are: Risk Achievement Worth (RAW), Risk Reduction Worth (RRW), Birnbaum (B) and Fussell-Vesely (FV) [1,2]. In a RM these values are updated in real time once plant components status is updated (e.g., under maintenance, off-line, testing). In addition, RMs can be used to optimize maintenance schedules so those safety features of the plant are below plant standard values. This paper presents an approach to create temporal profiles of RIMs (i.e., RM capabilities) given a temporal change of the plant configuration. Instead of employing data generated by ETs and FTs, the proposed approach will employ data generated by Dynamic PRA methods. In contrast to classical PRA methods, Dynamic PRA methods couple stochastic methods with safety analysis codes to determine risk associate to complex systems such as nuclear plants. Compared to classical PRA methods, they can evaluate with higher resolution the safety impact of timing and sequencing of events on the accident progression. We will describe how classical RIMs can be generated by Dynamic PRA data and then we will show how the temporal profiles of the RIMs can be generated given a temporal profile of the system configuration.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2016

Investigation of static and dynamic behavior of functionally graded piezoelectric actuated Poly-Si micro cantilever probe

In the present paper a novel functionally graded piezoelectric (FGP) actuated Poly-Si micro cantilever probe is proposed for atomic force microscope. The shear piezoelectric coefficient d{sub 15} has much higher value than coupling coefficients d{sub 31} and d{sub 33}, hence in the present work the micro cantilever beam actuated by d{sub 15} effect is utilized. The material properties are graded in the thickness direction of actuator by a simple power law. A three dimensional finite element analysis has been performed using COMSOL Multiphysics® (version 4.2) software. Tip deflection and free vibration analysis for the micro cantilever probe has been done. The results presented in the paper shall be useful in the design of micro cantilever probe and their subsequent utilization in atomic force microscopes.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Ab Initio Molecular Dynamics Analysis of Xenon Incorporation in Uranium Dioxide

The fission process in nuclear fuel produces volatile fission product gases, such as xenon, that migrate out of the fuel and into surrounding structures. Consequently, these fission product gases may affect thermal performance and integrity of the fuel. Fission gas release models, used in modern fuel performance codes such as BISON, are currently under investigation to improve their accuracy and ability to simulate the fission gas release phenomenon and its consequences. For uranium dioxide (UO{sub 2}), the most commonly used fuel in commercial power reactors, fission gas release models are known to have significant uncertainties. In the interest of improving such models, several complex diffusional mechanisms have been examined using a variety of techniques such as Nudge Elastic Band (NEB), utilizing both Density Functional Theory (DFT) and semi-empirical inter-atomic potential functions. One proposed diffusion mechanism in UO{sub 2} is through tetra-vacancy (i.e., 2U{sub V} + 2O{sub V}) structures, which is expected to provide a suitable means for the incorporation and diffusion of xenon in the fuel crystal. In this work, a model was developed to study the incorporation of xenon in UO{sub 2} via a tetra-vacancy using ab initio molecular dynamics (AIMD). This is a first principles technique that abandons the use empirical force fields as usually is the case of classical MD analysis. Furthermore, in contrast with static transition analysis tools such as NEB, AIMD is able to capture the dynamics of a given process. The translation of xenon within a tetra-vacancy has been investigated using ab-initio molecular dynamics. The transition frequency, barrier energy, and incorporation energy were extracted from the model, demonstrating its ability to capture a variety of parameters and its potential for use in studying fission gas diffusive behavior. Future refinements to the model will seek to develop additional insight into Xe and Kr mobility and will likely involve executing more elaborate AIMD simulations to investigate this phenomenon. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2016

SU-F-T-526: A Comparative Study On Gating Efficiency of Varian RPM Device and Calypso System

Purpose: In general, the linear accelerator is gated using respiratory signal obtained by way of external sensors to account for the breathing motion during radiotherapy. One of the commonly used gating devices is the Varian RPM device. Calypso system that uses electromagnetic tracking of implanted or surface transponders could also be used for gating. The aim of this study is to compare the gating efficiency of RPM device and the calypso system by phantom studies. Methods: An ArcCheck insert was used as the phantom with a Gafchromic film placed in its holder. The ArcCheck insert was placed on a Motion Sim platform and moved in the longitudinal direction simulating a respiratory motion with a period of 5 seconds and amplitude of ±6mm. The Gafchromic film was exposed to a 2 × 2cm{sup 2} field, i) with the phantom static, ii) phantom moving but ungated iii) gated with gating window of 2mm and 3mm. This was repeated with Calypso system using surface transponders with the same gating window. The Gafchromic films were read with an EPSON 11000 flatbed scanner and analysed with ‘Medphysto’ software. Results: The full width at half maximum (FWHM) as measured with film at the level of the film holder was 1.65cm when the phantom was static. FWHM measured with phantom moving and without gating was 1.16 cm and penumbra was 7 mm (80–20%) on both sides. When the beam was gated with 2 mm gating window the FWHM was 1.8 cm with RPM device and 1.9 cm with Calypso. Similarly, when the beam was gated with 3 mm window, the FWHM was 1.9cm with RPM device and 2cm with Calypso. Conclusion: This work suggests that the gating efficiency of RPM device is better than that of the Calypso with surface transponder, with reference to the latency in gating.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Energy Implications of In-Line Filtration in California

Occupant concern about indoor air quality (IAQ) issues has led to the increased use of more effective air filters in residential heating and cooling systems. This study performed measurements in ten California houses to determine the effects of changing filter performance and related characteristics on the energy use of the heating and cooling systems. Multiple filters were evaluated covering a wide range of filter effectiveness from simple low filtration fiberglass filters up to high efficiency filters that might be used by occupants concerned about IAQ. Sophisticated analysis and simulation tools used the field-testing results to determine filter impacts for a wide range of parameters and California climates. The results indicate that for MERV 10/11/13 filters the effects on energy use are moderate (<5%) over a wide range of performance conditions and climates. Using higher MERV 16 filters can lead to significantly increased energy use (>5%). The high airflow resistance of MERV 16 filters led to excess noise in some test houses from air bypassing the filter and the blower motor. Filter loading rates varied more from house to house than by MERV rating and overall were quite low in many of the homes. Filter related energy use does not need to be addressed for filters of MERV 10/11/13 and MERV 16 filters should only be used with low leakage tested ducts unless the filter is mounted at the blower compartment. MERV 16 filters should only be used if the filter area is sufficient to prevent noise issues and if the duct system has low air flow resistance and low leakage. Filters should be labeled for their air flow resistance, or static pressure at a particular flow rate, that would allow codes and standards to reference a particular performance specification and allow contractors and homeowners to make informed purchases.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Study of spatial spin-modulated structures by Mössbauer spectroscopy using SpectrRelax

SpectrRelax is an application for analysis and fitting of absorption and emission Mössbauer spectra. It includes a large selection of static and relaxation spectrum models, and allows fitting and searching for optimal model parameters. Recently, we have added new models for Mössbauer spectra of nuclides in spatial spin modulated structures. In these structures, spin density or direction changes in a periodic way along a single direction, and this wave is incommensurate with the underlying lattice. The models include Spin/Charge density wave, where the shape of this wave is represented as a sum of odd harmonics, Anharmonic spin modulation where the spin direction has a cycloidal type modulation, and a Spiral-like spin structure, in which magnetic moments rotate in a plane perpendicular to the wave propagation vector, forming a spiral.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

SU-E-T-83: A Study On Evaluating the Directional Dependency of 2D Seven 29 Ion Chamber Array Clinically with Different IMRT Plans

Purpose: To evaluate the directional dependency of 2D seven 29 ion chamber array clinically with different IMRT plans. Methods: 25 patients already treated with IMRT plans were selected for the study. Verification plans were created for each treatment plan in eclipse 10 treatment planning system using the AAA algorithm with the 2D array and the Octavius CT phantom. Verification plans were done 2 times for a single patient. First plan with real IMRT (plan-related approach) and second plan with zero degree gantry angle (field-related approach). Measurements were performed on a Varian Clinac-iX, linear accelerator equipped with a millennium 120 multileaf collimator. Fluence was measured for all the delivered plans and analyzed using the verisoft software. Comparison was done by selecting the fluence delivered in static gantry (zero degree gantry) versus IMRT with real gantry angles. Results: The gamma pass percentage is greater than 97 % for all IMRT delivered with zero gantry angle and between 95%–98% for real gantry angles. Dose difference between the TPS calculated and measured for IMRT delivered with zero gantry angle was found to be between (0.03 to 0.06Gy) and with real gantry angles between (0.02 to 0.05Gy). There is a significant difference between the gamma analysis between the zero degree and true angle with a significance of 0.002. Standard deviation of gamma pass percentage between the IMRT plans with zero gantry angle was 0.68 and for IMRT with true gantry angle was found to be 0.74. Conclusion: The gamma analysis for IMRT with zero degree gantry angles shows higher pass percentage than IMRT delivered with true gantry angles. Verification plans delivered with true gantry angles lower the verification accuracy when 2D array is used for measurement.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Hyper-fidelity depletion coupled with discrete pebble motion in pebble bed reactors

Pebble bed reactors have raised new interest during the past decade due to their attractive characteristics. Therefore, accurate simulations must be performed to better understand these systems and ensure optimal and safe designs. Most current methods use lower fidelity approaches with representative unit-cells or macro-zones with uniform fluxes, which have accuracy and flexibility limitations. A novel hyper-fidelity method for pebble bed reactors depletion is presented and internally couples Serpent 2 and a pseudo-motion routine. Pseudo-motion is applied handling vertical shifts of compositions in a static pebble bed, random reinsertion of used pebbles, insertion of fresh pebbles and used pebbles discarding. Associated with individual depletion to correctly determine the flux spectrum and composition in each pebble, this hyper-fidelity approach paves the way towards more accurate depletion calculation in pebble bed reactors. Using this method, a demonstration is completed on a small-scale reactor. In this application, the core reaches equilibrium, and the following data is extracted: core-wise parameters evolution, pebble-wise spatial and statistical distribution. Discarded pebbles are analyzed, and relevant information is shown. This work proves the feasibility of hyper fidelity depletion with Serpent 2, and the range of use for this method: reactor design and analysis for equilibrium and slow transients, lower fidelity methods validation and feeding fuel performance, thermal-hydraulics, or waste management models. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2015

SU-C-BRD-06: Sensitivity Study of An Automated System to Acquire and Analyze EPID Exit Dose Images

Purpose: The dosimetric consequences of errors in patient setup or beam delivery and anatomical changes are not readily known. A new product, PerFRACTION (Sun Nuclear Corporation), is designed to detect these errors by comparing the EPID exit dose image from each field of each fraction to those from baseline fraction images. This work investigates the sensitivity of PerFRACTION to detect the deviation of induced errors in a variety of realistic scenarios. Methods: Eight plans were created mimicking potential delivery or setup errors. The plans consisted of a nominal field and the field with an induced error. These were used to irradiate the EPID simulating multiple fractions with and without the error. Integrated EPID images were acquired in clinical mode and saved in ARIA. PerFRACTION automatically pulls the images into its database and performs the user defined comparison. In some cases, images were manually pushed to PerFRACTION. We varied the distance-to-agreement or dose tolerance until PerFRACTION showed failing pixels in the affected region and recorded the values. We induced errors of 1mm and greater in jaw, MLC, and couch position, 2 degree collimation rotation (patient yaw), and 0.5% to 1.5% in machine output. Both static and arc fields with the rails in or out were also acquired and compared. Results: PerFRACTION detected position errors of the jaws, MLC, and couch with an accuracy of better than 0.5 mm, and 0.2 degrees for collimator and gantry error. PerFRACTION detected a machine output error within 0.2% and detected the change in rail position. Conclusion: A new automated system for monitoring daily treatments for machine or patient variations from the first fraction using integrated EPID images was found to be sensitive enough to detect small positional, angular, and dosimetric errors within 0.5mm, 0.2 degrees, and 0.2%, respectively. Sun Nuclear Corporation has provided a software license for the product described.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Nevada National Security Site 2018 Data Report: Groundwater Monitoring Program, Area 5 Radioactive Waste Management Site

This report is a compilation of the groundwater and waste cell leachate sampling results from the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site, Nye County, Nevada. Groundwater samples from the aquifer immediately below the Area 5 RWMS have been collected and analyzed and static water levels have been measured in this aquifer since 1993. These groundwater data are evaluated for evidence of effects on the aquifer related to the Area 5 RWMS. Leachate from one lined mixed waste cell at the Area 5 RWMS (Cell 18) has been sampled since the cell opened in 2011. These leachate data are analyzed for hazardous contaminants to determine appropriate leachate handling and disposal. A second lined mixed waste cell at the Area 5 RWMS (Cell 25) began receiving waste in August 2018, but no leachate samples were collected or analyzed during 2018. This report includes data from 2014 through 2018 but focuses on the 2018 data. During 2018, groundwater samples were collected and static water levels were measured at three wells surrounding the Area 5 RWMS. Groundwater samples were collected at wells UE5PW-1, UE5PW-2, and UE5PW-3 on March 6 and August 14, 2018. Static water levels were measured at each of these wells on March 5, June 4, August 13, and October 25, 2018. Groundwater monitoring at the Area 5 RWMS complies with Title 40 Code of Federal Regulations (CFR) Part 264.97, General ground-water monitoring requirements , and 40 CFR 264.98, Detection monitoring program. Groundwater samples were analyzed for indicators of contamination (pH, specific conductance [SC], total organic carbon, total organic halides, and tritium) and, beginning in 2017, toxicity characteristic metals (arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver). General water chemistry parameters (calcium, iron, magnesium, manganese, potassium, sodium, sulfate, chloride, fluoride, bicarbonate, and silicate) were also measured. Results from samples collected in 2018 are within the limits for each parameter established by the Nevada Division of Environmental Protection in Resource Conservation and Recovery Act (RCRA) Permit NEV HW0101, Revision 6. Data from the shallow aquifer indicate there has been no measurable impact to the uppermost aquifer from the Area 5 RWMS, and there were no significant changes in measured groundwater parameters compared to previous years. Leachate from lined mixed waste Cell 18 drains into a sump and is pumped into an above ground tank. Samples are collected from the tank when the leachate volume approaches the 3,000-gallon tank capacity. During 2018, leachate samples were collected on March 1, 2018 and August 1, 2018. All leachate analysis results are below the regulatory levels for toxicity characteristic contaminants (40 CFR 261.24) and below the investigation levels for polychlorinated biphenyls (PCBs), tritium, pH, and SC specified in RCRA Permit NEV HW0101, Revision 6. No quantifiable PCB levels were detected in any leachate sample. Based on the leachate analysis results, RCRA Permit NEV HW0101 allowed all leachate collected from Cell 18 to be pumped from the collection tank and used for dust control at Cell 18.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗