Search NASA⌕ Search

SEARCH · Search NASA

Results for “Isotope Program”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Implementation of a Dose-based Compliance System for WCS - 19178

Waste Control Specialists LLC (WCS) operates a low-level radioactive waste (LLRW) disposal facility in Andrews, Texas. The site includes a compact waste facility (CWF) that began receiving waste in 2012, a federal waste facility (FWF) that started receiving waste in 2013, as well as a Resource Conservation and Recovery Act (RCRA) landfill and a byproduct facility. The current site license uses a complex system of concentration-based investigation levels and action levels (ILs and ALs) coupled with analytical decision levels (ADLs) that, when exceeded, require specific steps to be taken. These concentration-based ILs and ALs are media specific (i.e. air, soil, water), radionuclide specific, location specific, and disposal facility specific. This results in thousands of individual ILs, ALs, and ADLs that need to be managed and evaluated routinely in order to demonstrate compliance. Further, under the current system, each exceedance of an IL and AL can trigger comparisons to numerous additional isotopic ILs per sample, which is cumbersome, error prone, and costly. This paper describes implementation of a dose-based compliance system that has been developed to replace the existing system. The dose-based compliance system is implemented in RACER{sup C}, a cloud-based software developed by Risk Assessment Corporation (RAC). This system maintains all the analytical results related to the sampling and analysis conducted as part of the Radiological Environmental Monitoring Program (REMP) together with the geo-spatial data allowing instantaneous trending and analysis of the data. Further, the system contains the information needed to compare the analytical results to the new media-specific screening levels that have been developed, and the parameters and routines to compute doses using prescribed exposure scenarios and dose coefficients for compliance evaluation. Once measurement data are entered into RACER, the routines for continuous screening of air, soil, groundwater, and dosimeter data are triggered, and any sample result failing the screening step or exceeding the dose IL/AL is identified and flagged automatically for further review or action, as appropriate. Because RACER is cloud-based, the data, screening, and dose calculations can be accessed remotely at any time, providing a timely and efficient method for identifying any possible releases from the site to the environment as well as determining the potential dose consequences associated with a release. Furthermore, the system is accessible by the regulator providing transparency and ensuring they remain fully informed in an efficient manner. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2004

The Cassini-Huygens Mission: Exo/Astro/Cosmobiological Perspectives

One of the main objectives of the Cassini-Huygens mission is to explore Titan in great detail and to study in particular the many exobiological aspects of Titan, this exotic world which presents so many analogies with our planet. The Cassini orbiter and the Huygens probe, in a complementary way, will systematically study the many chemical and physical aspects of the different parts of what can be called the "geofluid" of Titan. Many of the twelve instruments of the Cassini orbiter and most of the six instruments of the Huygens probe will provide much information of crucial importance for our knowledge of the complexity of Titan's organic chemistry. This is particularly the case with the GC-M4S and ACP experiments which will provide the first in situ chemical (including isotopic and molecular) analyses of the gas and aerosol phases of Titan's atmosphere. Indeed, because of the presence of a dense atmosphere, mainly made of N2 with noticeable fraction of CH4, and of an environment very rich in organics, and of many couplings involved in the various parts of its geofluid, in spite of low temperatures and the absence of liquid water, Titan is a reference for studying prebiotic chemistry on a planetary scale. Many programs have recently been developed to study in detail Titan's chemistry, in direct connection with the Cassini-Huygens mission. They include new observations, development of photochemical models, laboratory determination of IR and UV spectra of organics of interest for Titan's atmosphere, and experimental studies, such as laboratory simulation of Titan's gas and aerosol organic chemistry. The paper will review the exobiological aspects of Titan. It will also present some of the new data concerning Titan s organic chemistry that have been obtained through the several possible approaches and discuss the exobiological implication of the potential scientific return of the Cassini-Huygens mission.

Raulin, F.↗
DOE OSTI2022

BoxScore - A real-time beam-diagnosis program for the CAEN digitizer x730 series

BoxScore is a real-time beam diagnosis and monitoring program for the CAEN x730 series digitizer, developed for the ATLAS in-flight system at Argonne National Laboratory. The CAEN x730 series digitizer, with built-in Digital Pulse Processing for the Pulse-Height-Analysis, digitizes the input signal in real-time and processes it using a trapezoidal filter. BoxScore reads the digitizer’s buffer directly, builds and saves events to local files, plots histograms for particle identification, and outputs the rates of selected isotopes every second. Implementation of BoxScore has shortened the time needed for in-flight beam-tuning and has potential applications for other nuclear physics experiments.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Play Fairway Analysis: Structurally Controlled Geothermal Systems in the Eastern Great Basin Extensional Regime, Utah

A research team with membership from the University of Utah/Energy & Geoscience Institute, the University of Utah/Dept. of Geology & Geophysics, and the Utah Geological Survey, undertook a play fairway analysis (PFA) for geothermal resources in the Eastern Great Basin (EGB) extensional tectonic regime of western Utah. This is a high-priority region for geothermal exploration because active Basin and Range (B&R) extension with volcanism having a N-S strike is superimposed upon pre-existing E-W belts of plutonic rocks and large-scale structural lineaments. Cumulative heat flow along the N-S strike of the state totals approximately 5 GWt above background stable interior. Three electricity producing power plants currently exist with substantial potential for increase. Succinctly, our PFA approach aims to resolve potential sources of heat and permeability in the region, which are the two principal criteria for establishing a geothermal resource. An initial Phase 1 was carried out using only existing geoscientific data in the area. Criteria selected for focusing heat potential include direct heat flow measurements in boreholes, magnetotelluric (MT) low resistivity anomalies, fluid/gas geochemistry, and proximity to recent volcanic eruptions. Permeability is established through geological structures (fault density, critically stressed areas, seismicity, gravity), and MT low resistivity anomalies. In Phase II of this PFA project, additional geological, geophysical and geochemical data were acquired and analysis carried out primarily over promising composite common risk (CCR) areas initially identified in Phase I in order to focus prospectivity and prepare for drilling recommendations. These prospects are near the Twin Peaks rhyolite field, high heat flow areas north of the producing Cove Fort system, and geophysical structure beneath the Crater Knoll area off the northeast flank of the Mineral Mountains. Additional data included MT site fill-in, structural mapping and analysis using high-resolution imagery, gravity and on-ground mapping, Nodal 3C passive seismic collection, and passive 3He surveying. Heat source and permeability potential are again expressed in terms of their individual common risk segment (CRS) maps, with a color scheme using green for most favorable (low risk) and red for least favorable (high risk). Diverse data types are united through the technique of probability kriging, which establishes prospectivity thresholds for each data type and then computes probability of exceeding that threshold over the PFA area. Modified CRS and CCRS maps are compared to those of Phase I to highlight tighter prospectivity focus. In doing so, the prospectivity threshold for heat was increased significantly to narrow the targeting. In the final Phase III of this project where a recommended deep thermal gradient hole was sited, additional geophysical, geochemical and geological field collection and analysis was carried out to refine drill hole targeting. This includes prospect-scale MT, gravity, structure, passive seismic deployment (Cove Fort area), and detailed 3He isotope profiling. It was the recommendation of the DOE Technical Monitoring Team (TMT) that one or more holes be sited in the north-ern Cove Fort area where legacy TG gradient holes showed high cumulative heat flow. These were to be of moderate depth, 2000-3000 feet, to reach the geothermal fluid table expected to start in excess of 1000 feet depth. The drilling organization stipulated by the DOE/GTO was that of the USGS Research Drilling Program (RDP) centered in Las Vegas, NV. A detailed well plan, appended to this report, was developed principally by Dr. Ben Barker consulting to University of Utah, Dr. Steve Pye on the DOE TMT, Mr. Steven Crawford of the USGS-RDP, and the project PI Phil Wannamaker. However, temperature and possible H 2 S at the systems lead to cancellation of the drilling last-minute as this appeared outside the experience base of the USGS-RDP. We hope to have the opportunity to revisit the test drilling and expand the Play Fairway Analysis of this region at some point in the future.

15 GEOTHERMAL ENERGY↗
DOE OSTI2017

Considerations and Lessons Learned from the Use of Gamma Spectroscopy Systems at FUSRAP Project Sites - 17459

This paper will discuss the application of gamma spectroscopy systems for analysis of environmental media samples for parents and daughter progeny of the Natural Uranium and Thorium Decay Series radionuclides. The concentrations and relative ratios of naturally occurring isotopes are used to confirm the presence of FUSRAP-related wastes and for understanding the associated potential dose and health risks. Focus will be given to lessons learned from the set-up and operation of onsite gamma spectroscopy laboratories used to provide stakeholders with defensible and timely results to support FUSRAP site investigations and remediation including adaptive survey design implementation, physical remediation and waste transport, and confirmatory final status survey activities. This paper focuses on the potential impacts to gamma spectroscopy measurement accuracy from the following: - Bias caused by sample matrix effects as well as use of different library reference values between performance evaluation study providers and testing laboratories; - Use of calibration sources with limited energy ranges, and; - Selection of available alternative isotopic decay reference data for the input of line energies and their intensities. These lessons learned include discussing how inter-laboratory measurement differences from blind performance evaluation samples are affected by the manufacturer's measurement method, including equilibrium assumptions; the isotope decay information source library used by the study provider and participating laboratories; and calibration source geometry/density variances from actual sample conditions. Any of these factors can significantly impact the accuracy of reported results data. Deepening the reader's understanding of the various factors that impact the accuracy, interpretation, and overall usability of gamma spectroscopy results data from laboratories will help ensure defensible decision-making and cost-effective mission implementation within FUSRAP and similar remediation programs. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Investigation of candidates for reactor produced radioactive materials in support of radiological training exercises

Bromine-82, Potassium-42 and Copper-64 have been successfully adopted as radioactive surrogates for outdoor large area contamination training. The goal of this project was to discover new materials that could supplement potassium bromide (KBr) and copper pellets in radiological dispersal device (RDD) training events to reduce the down time of the training fields and to broaden the toolbox of the RDD surrogate training event program at Idaho National Laboratory. Of the ten different materials investigated, sodium nitrite, gallium metal, and gallium oxide presented the greatest promise as potential materials to replace potassium bromide in RDD training events.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2022

Hot Cell Manipulator Inventory and Recommendations

During the spring of 2021 repeated manipulator failures in the hot cells of Building 7920 contributed to significant delays in Californium-252 ( 252 Cf) mission execution and loss of rapidly decaying 252Cf product. At the same time, funds became available in the 252 Cf program budget for equipment purchases and upgrades. Accordingly, the 252 Cf program manager requested (1) an inventory of the manipulators used in six Oak Ridge National Laboratory (ORNL) buildings (7920, 7930, 4501, 3047, 3025E, and 3525), (2) an inventory of spare manipulators, and (3) a recommendation on whether to invest 252 Cf funds to purchase additional or upgraded manipulators.

07 ISOTOPE AND RADIATION SOURCES↗
NASA NTRS1996

Research activities in nuclear astrophysics and related areas

NASA/GRO grant NAG 5-2081, at the University of Chicago, has provided support for a broad program of theoretical research in nuclear astrophysics and related areas, with regard to gamma-ray and hard X-ray emission from classical nova explosions. This research emphasized the possible detection of 22Na gamma-ray line emission from nearby novae involving ONeMg white dwarfs, the detailed examination of 26Al production in novae, and the possible detection of the predicted early gamma ray emission from novae that arises from the decay of the short lived, positron emitting isotopes of CNO elements. Studies of nova related problems have consumed an increasing fraction of the Principal Investigator's research efforts over the past decade. Current research addresses problems associated with the standard model for the outbursts of the classical novae: the occurrence of thermonuclear runaways (TNR) in the accreted hydrogen rich envelopes on white dwarfs in close binary systems (see, e.g., the reviews by Truran 1982; and Shara 1989). Research in progress and planned for the next three years has three main objectives: (1) to gain an improved understanding of the early evolution of the light curves of, particularly, the fastest novae; (2) to gain an improved understanding of the relative importance of the various possible mechanisms of envelope hydrogen depletion (e.g. winds, common envelope driven mass loss, and nuclear burning) to the long term evolution of novae in outburst; and (3) to seek to provide a somewhat more definitive statement of the role of classical novae in nucleosynthesis. Our proposed 2-D studies of convection during the early phases of the TNR and our systematic attempt to incorporate an improved treatment of radiation hydrodynamics into the hydrodynamic code utilized in our calculations, are particularly relevant to the first of these objectives. Further 2-D studies of the effects of common envelope evolution are intended to provide more realistic constraints on the mass depletion mechanisms. Finally, detailed calculations of the thermonuclear history of the matter ejected in novae will be carried out for representative nova configurations involving both carbon-oxygen (CO) and oxygen-neon-magnesium (ONeMg) white dwarfs.

Source record↗
DOE OSTI2019

The Need for Minor Actinide Production

The US Department of Energy (DOE) manages an inventory of materials that contains a range of long-lived radioactive isotopes that were produced from the 1960s through the 1980s by irradiating targets in production reactors to produce special heavy isotopes for DOE programmatic use, scientific research, and industrial and medical applications. Oak Ridge National Laboratory (ORNL) used many of these materials as feedstock in the calutron Electromagnetic Isotope Enrichment Facility (EIEF), one of only two facilities in the world with capabilities to enrich radioisotopes in multigram quantities. Both the production reactors and enrichment facilities have been shut down, and many of these unique materials will never be produced again. ORNL maintains a major portion of the United States’ inventory of these materials and uses them in DOE’s center for production, storage, and distribution of transuranium isotopes (plutonium through californium) to the user community. The US inventory of enriched actinides is being depleted, and attempts for over a decade to obtain critical supplies from foreign sources have been unsuccessful. Significant strides have been made recently in the development of new and improved enrichment technologies to replace the previous electromagnetic separations techniques. This paper summarizes the US’s need for production of high-purity enriched actinides by national security, nuclear nonproliferation, and basic research programs.

Robinson, Sharon↗
DOE OSTI2019

r-Process Nucleosynthesis: Connecting Rare-Isotope Beam Facilities with the Cosmos

This is a pivotal time for the study of r-process nucleosynthesis. Recently, a neutron star merger GW170817 was observed in extraordinary detail with gravitational waves and electromagnetic radiation from radio to γ rays. The very red color of the associated kilonova suggests that neutron star mergers are an important r-process site. Astrophysical simulations of neutron star mergers and core collapse supernovae are making rapid progress. Detection of both electron neutrinos and antineutrinos from the next Galactic supernova will constrain the composition of neutrino-driven winds and provide unique nucleosynthesis information. Finally, FRIB and other rare-isotope beam facilities will soon have dramatic new capabilities to synthesize many neutron-rich nuclei that are involved in the r-process. The new capabilities can significantly improve our understanding of the r-process and likely resolve one of the main outstanding problems in classical nuclear astrophysics. Yet, to make best use of the new experimental capabilities and to fully interpret the results, a great deal of infrastructure is needed in many related areas of astronomy, astrophysics, and nuclear theory. We place these experiments in context by discussing astrophysical simulations and observations of r-process sites, observations of stellar abundances, Galactic chemical evolution, and nuclear theory for the structure and reactions of very neutron-rich nuclei. This review paper was initiated at a three week International Collaborations in Nuclear Theory program in June 2016, where we explored promising r-process experiments and discussed their likely impact, and their astronomical, astrophysical, and nuclear theory context.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1977

AR-39Ar-40 dating of basalts and rock breccias from Apollo 17 and the malvern achondrite

The principles and the potential of the Ar-39/Ar-40 dating technique are illustrated by means of results obtained for 12 Apollo 17 rocks. Emphasis is given to methodical problems and the geological interpretation of lunar rock ages. Often it is ambigious to associate a given lunar breccia with a certain formation, or a formation with a basin. In addition, large-scale events on the Moon have not necessarily reset radiometric clocks completely. One rock fragment has a well-defined plateau age of 4.28 b.y., but the ages of two Apollo 17 breccias define an upper limit for the formation age of the Serenitatis basin at 4.05 b.y. Ages derived from five mare basalts indicate cessation of mare volcanism at Taurus-Littrow approximately 3.78 b.y. ago. Ca/Ar-37 exposure ages show that Camelot Crater was formed by an impact approximately 95 m.y. ago. After a short summary of the lunar timetable as it stands at the end of the Apollo program, we report about Ar-39/Ar-40 and rare gas studies on the Malvern meteorite. This achondrite resembles lunar highland breccias in texture as well as in rare-gas patterns. It was strongly annealed at some time between 3.4 and 3.8 b.y. ago. The results indicate that very similar processes have occurred on the Moon and on achondritic parent bodies at comparable times, leading to impact breccias with strikingly similar features, including the retention of rare-gas isotopes from various sources.

Kirsten, T.↗
NASA NTRS1977

Cosmic ray investigation for the Voyager missions: Energetic particle studies in the outer heliosphere - and beyond

The Voyager mission cosmic ray detector system, consisting entirely of solid-state charged-particle detectors, is designed to measure the energy spectrum of electrons in the range 3 to 110 MeV and the energy spectra and elemental composition of cosmic ray nuclei from hydrogen through iron in the range 1 to 500 MeV/nuc; for isotopes of hydrogen through sulfur the range is approximately 2 to 75 MeV/nuc. The cosmic ray investigation deals with the energy content, origin and acceleration process, and dynamics of cosmic rays in the galaxy, with particular attention given to low-energy phenomena in interstellar space and the outer solar system. The precise measurement of three-dimensional stream patterns of nuclei from H to Fe, as well as electrons over a wide energy range, is the data acquisition program emphasized.

Stone, E. C.↗
DOE OSTI2017

Volatility Studies of Lanthanide Hexafluoroacetylacetone Chelates

The Advanced Fuels Campaign within the Fuel Cycle Research and Development program of the Department of Energy (DOE) Office of Nuclear Energy is currently investigating a number of advanced nuclear fuel cladding concepts to improve the accident tolerance of light water reactors (LWRs). Some of the leading candidates to replace traditional zirconium-based cladding are alumina-forming ferritic alloys (e.g., FeCrAl) and silicon carbide (SiC) composites. Oak Ridge National Laboratory has developed experimental designs to irradiate thin-walled cladding tubes with representative geometry in the High Flux Isotope Reactor (HFIR) under relevant LWR temperatures and in some cases under prototypic heat flux. These designs allow for post-irradiation examination (PIE) of cladding which closely resembles expected commercially viable geometries and microstructures. PIE will include studies of dimensional change, microstructure variation, mechanical performance, etc. The experiments were designed using relatively inexpensive rabbit capsules for the irradiation vehicle. The simplistic designs combined with the extremely high neutron flux in the HFIR allow for rapid testing of a large test matrix, thus reducing the time and cost for moving advanced cladding materials closer to commercialization. This work describes the capsule designs that have been developed at ORNL, some initial results, and plans for future irradiations.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

HydroEcoLSTM: A Python package with graphical user interface for hydro-ecological modeling with long short-term memory neural network

Machine learning (ML) is emerging as a promising tool for modeling hydro-ecological processes due to the increasing availability of large environmental data. However, the use of ML requires sufficient programming knowledge due to a lack of a graphical user interface (GUI). In this study, we introduced a GUI package, named HydroEcoLSTM, with the long short-term memory network (LSTM) as the core model, that allows non-ML experts to utilize their domain knowledge to construct complex ML models. We demonstrated the functionalities of HydroEcoLSTM with two practical examples, including (1) predictions of streamflow in both gauged and ungauged catchments and (2) predictions of multiple outputs (i.e., streamflow and isotope transport from two catchments). The simulation results obtained in both case experiments are satisfactory. In the first example, the average Nash–Sutcliffe Efficiency (NSE) for streamflow simulation during the testing period is 0.79 while the application of the trained model in two assumed ungauged catchments also achieves the average NSE of 0.68. In the second example, the average NSE for streamflow and instream isotope simulation during the testing period is 0.71. Ultimately, applications of HydroEcoLSTM with real-world examples demonstrate its potential use for practical applications and research without requiring extensive coding skills.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1991

Stratospheric spectroscopy with the far-infrared spectrometer (FIRS-2) - Overview and recent results

The Smithsonian Astrophysical Observatory's program of balloon-borne stratospheric spectroscopic measurements is described, including instrumentation, recent scientific results, and future plans. The design and operation of the FIRS-2 far-infrared spectrometer is discussed. The current status of our efforts to recover mixing-ratio profiles with about 1 percent precision is presented. Representative recent results are shown giving mixing-ratio profiles from 20 to 50 km, selected from the suite HOCl, HCl, HF, NO2, N2O, HNO3, OH, HO2, H2O2, H2O (and isotopes), O2 (and isotopes), O3 (and isotopes), and CO2 (and isotopes). The utility of O2 and CO2 spectral lines for information on view angle or temperature and pressure is discussed. Future plans are mentioned, including the use of FIRS-2 on a balloon platform for UARS correlative measurements, the use of FIRS-2 on the NASA DC-8 platform for polar measurements, and the potential benefits of a FIRS instrument on a Shuttle platform.

Traub, Wesley A.↗
NASA NTRS2023

Technical Basis Related to the Posture of NASA’s Office of Safety and Mission Assurance for the Launch of Radioactive Material Other than Space Nuclear Systems: Volume 1–Overview of Analysis and Results

NASA has launched and reentered payloads containing radioactive material for over 50 years. The isotopes, their quantity, and their form have varied significantly. The handling of this material prior to its integration into the spacecraft at the launch Center (and after its return to Earth after flight, if applicable) falls under the purview of the Office of the Chief Health and Medical Officer, while after the radioactive material is integrated into the spacecraft at the launch Center, it falls under the purview of the Office of Safety and Mission Assurance’s (OSMA) Nuclear Flight Safety Program. Historically, OSMA concurrence was required for any launch or reentry involving radioactive material. However, OSMA recently revisited this posture due to changes in the Federal policy in this area, and the significant accrued experience. The current report represents the more quantitative study envisioned in the recent change in posture. More specifically, this document addresses the potential risks and other considerations associated with launching small quantities of radioactive material (below the level requiring the Federally-mandated process in National Security Presidential Memorandum- (NSPM-) 20, “Presidential Memorandum on Launch of Spacecraft Containing Space Nuclear Systems” (USG, 2019) to provide the technical basis for when such activities require OSMA concurrence versus notification, as it relates to nuclear flight safety.

Don Helton↗
NASA NTRS1976

Petrology of lunar rocks and implication to lunar evolution

Recent advances in lunar petrology, based on studies of lunar rock samples available through the Apollo program, are reviewed. Samples of bedrock from both maria and terra have been collected where micrometeorite impact penetrated the regolith and brought bedrock to the surface, but no in situ cores have been taken. Lunar petrogenesis and lunar thermal history supported by studies of the rock sample are discussed and a tentative evolutionary scenario is constructed. Mare basalts, terra assemblages of breccias, soils, rocks, and regolith are subjected to elemental analysis, mineralogical analysis, trace content analysis, with studies of texture, ages and isotopic composition. Probable sources of mare basalts are indicated.

Ridley, W. I.↗