Search NASA⌕ Search

SEARCH · Search NASA

Results for “RADIOACTIVE”

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 1,495 records · Page 83

Definition of "Small Gram Quantity Contents" for Type B Radioactive Material Transportation Packages: Activity-Based Content Limitations, Rev. 1

The results presented are a compendium of allowable masses (and activities) of a variety of different isotopes ( with varying impurity levels of beryllium in some of the actinide isotopes) that, when loaded in an unshielded packaging, do not result in an external dose rate on the surface of the package that exceeds 190 mrem/hr.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

BNFL 3013 Containers for Radioactive material Transportation

The DOE Standard, Stabilization, Packaging, and Storage of Plutonium-Bearing Materials, DOE-STD-3013-1994 — i.e., the 3013 Standard — was issued in December 1994, by the DOE weapons complex for the stabilization, packaging and safe storage of excess plutonium-bearing metal and oxides. Based on the 3013 Standard, the BNFL container was designed and developed to remove excess plutonium material from the Hanford and Rocky Flats Sites. The BNFL 3013 containers were put into certified transportation packages and sent to the Savannah River Site for storage and later disposition.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Development of Innovative Radioactive Isotope Production Techniques at the Pennsylvania State University Radiation Science and Engineering Center

The Penn State Breazeale Nuclear Reactor (PSBR) at the Radiation Science and Engineering Center (RSEC) has produced radioisotopes for research and commercial purposes since 1956. With the rebirth of the radiochemistry education and research program at the RSEC, the Center stands poised to produce a variety of radioisotopes for research and industrial work that is in line with the mission of the DOE Office of Science, Office of Nuclear Physics, Isotope Development and Production Research and Application Program. The RSEC received funding from the Office of Science in 2010 to improve production techniques and develop new capabilities. Under this program, we improved our existing techniques to provide four radioisotopes (Mn-56, Br-82, Na-24, and Ar-41) to researchers and industry in a safe and efficient manner. The RSEC is also working to develop new innovative techniques to provide isotopes in short supply to researchers and others in the scientific community, specifically Cu-64 and Cu-67. Improving our existing radioisotopes production techniques and investigating new and innovative methods are two of the main initiatives of the radiochemistry research program at the RSEC.

07 ISOTOPE AND RADIATION SOURCES↗

Thermal-Hydrology Simulations of Disposal of High-Level Radioactive Waste in a Single Deep Borehole

Simulations of thermal-hydrology were carried out for the emplacement of spent nuclear fuel canisters and cesium and strontium capsules using the PFLOTRAN simulator. For the cesium and strontium capsules the analysis looked at disposal options such as different disposal configurations and surface aging of waste to reduce thermal effects. The simulations studied temperature and fluid flux in the vicinity of the borehole. Simulation results include temperature and vertical flux profiles around the borehole at selected depths. Of particular importance are peak temperature increases, and fluxes at the top of the disposal zone. Simulations of cesium and strontium capsule disposal predict that surface aging and/or emplacement of the waste at the top of the disposal zone reduces thermal effects and vertical fluid fluxes. Smaller waste canisters emplaced over a longer disposal zone create the smallest thermal effect and vertical fluid fluxes no matter the age of the waste or depth of emplacement.

Hadgu, Teklu↗

Characterization of Aged Radioactive Pollucite

The objective of this task was to provide information to better understand the long-term effects of decay on the stability of crystalline pollucite (CsAlSi 2 O 6 , also known as Cs-leucite). This decay is a key scientific issue in the assessment of the long-term stability, and hence performance, of pollucite as a waste form for 137 Cs. Most previous work on radiation effects in waste forms focused on alpha radiation, which produces more displacements per decay than beta radiation. However, the results of decay with beta radiation, which changes both the ionic radius and the valence of the element undergoing decay (0.160 nm for Ba 2+ vs. 0.188 nm for Cs + ), are likely to predominate over cascade damage. The resulting changes in coordination chemistry may destabilize the waste form, permitting release of radionuclides to the accessible environment.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Monitoring Potential Transport of Radioactive Contaminants in Shallow Ephemeral Channels: FY2013 and FY2014 (revised)

The Desert Research Institute (DRI) is conducting a field assessment of the potential for contaminated soil to be transported from the Smoky Contamination Area (CA) as a result of storm runoff, which supports National Nuclear Security Administration (NNSA) efforts to complete regulatory closure of the Soils Corrective Action Unit (CAU) contamination areas. The work is intended to confirm the likely mechanism of transport and determine the meteorological conditions that might cause movement of contaminated soils, as well as determine the particle size fraction that is most closely associated with transported radionuclide-contaminated soils. These data will facilitate the appropriate closure design and post-closure monitoring program.

54 ENVIRONMENTAL SCIENCES↗

File format for normalizing radiological concentration exposure rate and dose rate data for the effects of radioactive decay and weathering processes

This report specifies the electronic file format that was agreed upon to be used as the file format for normalized radiological data produced by the software tool developed under this TI project. The NA-84 Technology Integration (TI) Program project (SNL17-CM-635, Normalizing Radiological Data for Analysis and Integration into Models) investigators held a teleconference on December 7, 2017 to discuss the tasks to be completed under the TI program project. During this teleconference, the TI project investigators determined that the comma-separated values (CSV) file format is the most suitable file format for the normalized radiological data that will be outputted from the normalizing tool developed under this TI project. The CSV file format was selected because it provides the requisite flexibility to manage different types of radiological data (i.e., activity concentration, exposure rate, dose rate) from other sources [e.g., Radiological Assessment and Monitoring System (RAMS), Aerial Measuring System (AMS), Monitoring and Sampling). The CSV file format also is suitable for the file format of the normalized radiological data because this normalized data can then be ingested by other software [e.g., RAMS, Visual Sampling Plan (VSP)] used by the NA-84’s Consequence Management Program.

97 MATHEMATICS AND COMPUTING↗

Monitoring Potential Transport of Radioactive Contaminants in Shallow Ephemeral Channels: FY2015 and FY2016

The Desert Research Institute (DRI) is conducting a field assessment of the potential for contaminated soil to be transported from the Smoky Contamination Area (CA) as a result of storm runoff. This activity supports Nevada Nuclear Security Administration (NNSA) efforts to complete regulatory closure of the Soils Corrective Action Unit (CAU) contamination areas. The work is intended to confirm the likely mechanism of transport and determine the meteorological conditions that might cause movement of contaminated soils, as well as determine the particle size fraction that is most closely associated with transported radionuclide-contaminated soils. These data will facilitate the appropriate closure design and post-closure monitoring program.

54 ENVIRONMENTAL SCIENCES↗

Monitoring Potential Transport of Radioactive Contaminants in Shallow Ephemeral Channels: FY2017

The Desert Research Institute (DRI) is conducting a field assessment of the potential for contaminated soil to be transported from the Smoky Site Contamination Area (CA) as a result of storm runoff. This activity supports U.S. Department of Energy (DOE) Environmental Management Nevada Program (EM-NV) efforts to establish post-closure monitoring plans for the Smoky Site Soils Corrective Action Unit (CAU) 550. The work is intended to confirm the likely mechanism of transport and determine the meteorological conditions that might cause the movement of contaminated soils, as well as determine the particle size fraction that is most closely associated with transported radionuclide-contaminated soils. These data will facilitate the design of the appropriate post-closure monitoring program. In 2011, DRI installed a meteorological monitoring station on the west side of the Smoky Site CA and a hydrologic (runoff) monitoring station within the CA, near the east side. Air temperature, wind speed, wind direction, relative humidity, precipitation, solar radiation, barometric pressure, soil temperature, and soil water content are collected at the meteorological station. The maximum, minimum, and average or total values (as appropriate) for each of these parameters are recorded for each 10-minute interval. The maximum, minimum, and average water depth in the flume installed at the hydrology station are also recorded for every 10-minute interval. This report presents data collected from these stations during fiscal year (FY) 2017.

(CA)↗

Second Line of Defense Program Radioactive Source Information and Policy Guide. Revision 1.2

The Second Line of Defense (SLD) Program works with partner countries to enhance their capabilities in deterring, detecting, and interdicting the illicit trafficking of nuclear and radiological materials through international borders by providing radiation detection equipment and related training. The program supports sustainability by working with partner countries to establish the functional and operational requirements for people, processes, and equipment that promote proficient performance throughout the lifetime of the radiation detection system.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

Computational Studies of Solid Stoppers for Generating Intense Exotic Radioactive Ion Beams at FRIB

Low-emittance beams of rare isotopes at low energies (less than 3 MeV/u) are required for many high precision measurements in nuclear science research. Such beams will be produced at the Facility for Rare Isotope Beams (FRIB) by first slowing down and thermalizing or stopping fast fragmentation beams, and subsequently reaccelerating them to the required energies for experiments. The use of a solid stopper has the potential to provide high-intensity reaccelerated beams of many species. We performed simulations of the processes critical for generating beams in solid stoppers, including beam heating, external heating, diffusive release, effusive transport, and surface sticking. Using a variety of software tools, we investigated the viability of numerous solid stopper system designs for FRIB. We present our computational approach, the physical processes we modeled, the codes we used, and our results. We conclude with a proof-of-concept solid stopper system that releases ions sufficiently quickly for experiments with unstable reaccelerated beams at FRIB.

47 OTHER INSTRUMENTATION↗