Radiochemical Separation and Spectrometric Analyses of Americium and Plutonium [Thesis] [Slides]
Abstract not provided.
07 ISOTOPE AND RADIATION SOURCES↗
SEARCH · Engineering Papers
Results for “Isotopes and Radiation Sources”
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.
Radiological Consequence Evaluation for Dragonfly Mission
The scoping calculations presented in this report were developed to provide a conservative estimate of radiological dose consequences associated with launch accidents involving one multi-mission radioisotope thermoelectric generator (MMRTG) and possibly up to 43 light-weight radioisotope heater units (LWRHUs) for the upcoming National Aeronautics and Space Administration (NASA) Dragonfly mission. This report summarizes dose consequence analysis from SAND2019-11148, “Nuclear Risk Assessment 2019 Update for the Mars 2020 Mission Environmental Impact Statement,” referred to in this document as the Mars 2020 nuclear risk analysis (NRA) and compares those results to a parametric analysis used to analyze potential dose consequences for the Dragonfly mission.
07 ISOTOPE AND RADIATION SOURCES↗
Production of Radiohalogens: Bromine and Astatine for Imaging and Therapy
Objective: This collaborative proposal between the University of Alabama at Birmingham (UAB), University of Wisconsin, Madison (UWisc) and the University of Pennsylvania (Penn) aims to research the efficient production of high purity, clinical grade radiohalogens for preclinical and translational applications by optimizing the cyclotron targetry and separation chemistry of 76,77Br and 211At for use in imaging and therapy. Proposed Research and Methods: During the course of this project, faculty and trainees at our three institutions will use the complementary infrastructure available to examine the 76Se(p,n)76Br, 77Se(p,n)77Br, 78Se(p,2n)77Br, natAs(α,2n)77Br ,80Kr(p,α)77Br and 209Bi(α, 2n)211At reactions as routes to the production of these valuable radiohalogens for imaging and therapy. Working together we aim to optimize both solid and gas targetry, including reclamation of expensive enriched material. We will develop high yielding recovery processes based on dry distillation and ion exchange techniques. We will also create a comprehensive set of quality control procedures to ensure we are producing our radioisotopes in the highest radiochemical and chemical purity possible. By bringing three institutions together to perform research and development we provide the unique opportunity to build an everlasting cooperative culture in the field of nuclear medicine research by enabling academic centers to delve into the fields of radiohalogen chemistry. In addition, each institution involved holds different skills and expertise and a collaborative grant will facilitate the cross-pollination of ideas, techniques, and build strong bonds that unite under the DOE mission. Additionally, our work does not stop at the completion of this proposal, rather this proposal allows us to gain the momentum needed to get our research and developmental efforts off the ground thereby creating a network of three institutions dedicated to the advancement of isotope production for medical research.
07 ISOTOPE AND RADIATION SOURCES↗
The Science of the Bomb
Uranium is a naturally occurring element with wo isotopes of interest – U238 and U235; U235 is useful for its ability to sustain a chain reaction; Chain reactions are the fundamental way that nuclear reactors work, as well as how bombs work; Enrichment of U235 is important for both nuclear energy as well as nuclear weapons; A safety focus is at the center of all nuclear operations in the United States
07 ISOTOPE AND RADIATION SOURCES↗
Test Results for Checking Reliability of Selected ENDF/B-VIII.0 Evaluated Uncertainties
This report summarizes error messages obtained from counter-checking whether 1 H, 9 Be, 12 C, 27 Al, 235,238 U and 238–242 Pu relative uncertainties of ENDF/B-VIII.0 are realistic. Large parts of this report were generated automatically by the code CovVal. This code allows to test the reliability of relative uncertainties of any isotope. It gives generic error and warning messages if evaluated relative uncertainties of a particular reaction are likely under- or over-estimated. In addition to these error and warning messages, I added comments whether the flagged uncertainties are truly under- or overestimated. I call out these uncertainties that should be further investigated and corrected by an evaluator for an upcoming release of ENDF/B-VIII.1.
07 ISOTOPE AND RADIATION SOURCES↗
Utility of Sr and Nd isotope signatures in U ores and UOCs [Slides]
Abstract not provided.
07 ISOTOPE AND RADIATION SOURCES↗
Gamma ray analysis of the K2 containers
The K2 containers contain PuO2 with 238 Pu being the most abundant isotope of all plutonium isotopes. The purpose of this analysis is to determine the light element impurities in the PuO2. These light elements can interact with the alpha particles from plutonium decay to release gamma rays, protons, and neutrons through the reactions (α,α’), (α,p), and (α,n) respectively. The gamma rays released by the interactions can be measured and compared with the gamma rays released by the plutonium. The ratios of the gamma rays from the interactions and the plutonium gamma rays allow for the determination of the impurities in the items. The elements that can be detected are Lithium (Z=3), Beryllium (Z=4), Boron (Z=5), Fluorine (Z=9), Sodium (Z=11), Magnesium (Z=12), Aluminum (Z=13), Silicon (Z=14), Phosphorous (Z=15), Chlorine (Z=17), and Potassium (Z=19).
07 ISOTOPE AND RADIATION SOURCES↗
Gamma spectrometry uranium isotopic analysis rodeo: Summary of GADRAS results
This report summarizes GADRAS methods and gamma spectrometry rodeo uranium isotopic analysis results for high energy resolution H3D M400 cadmium zinc telluride (CZT) and ORTEC Micro Detective high-purity germanium (HPGe) spectra of uranium isotopic standards collected at Oak Ridge National Laboratory (ORNL) and Lawrence Livermore National Laboratory (LLNL) over a two-year measurement campaign. During the campaign, measurements were performed with the detectors unshielded, side shielded, and collimated. In addition, measurements of the uranium isotopic standards were performed unshielded and shielded.
07 ISOTOPE AND RADIATION SOURCES↗
Operational and Mission Highlights A Monthly Summary of Top Achievements February 2022
To support the Laboratory’s pit mission, the Associate Laboratory Directorate for Plutonium Infrastructure on January 31, 2022, took the first step in establishing operations at TA-55 that run 24 hours a day, seven days a week.
07 ISOTOPE AND RADIATION SOURCES↗
Recommended Updates to Solubility Controls for Modeling Leaching of Technetium, Uranium, Neptunium, Plutonium, and Iodine from the Residual Waste Layer of Closed Savannah River Site High Level Waste Tanks
The objective of this report is to relate waste leaching experiments by the Savannah River National Laboratory (SRNL) to performance assessment modeling of release of several radionuclides from residual waste in closed high-level waste tanks. SRNL leached residual waste from Tanks 18F and 12H with solutions simulating the modeled evolution of pore fluids in residual waste layers of closed tanks through various stages of grout degradation. Tc-99, uranium isotopes, Np-237, plutonium isotopes, and I-129 were analyzed in the leachate multiple times over 90 days.
07 ISOTOPE AND RADIATION SOURCES↗
NACS 2022 FRIB Investment Strategy
The Facility for Rare Isotope Beams (FRIB) that will begin operations later this year will vastly increase the number of unstable isotopes available for experiments that, together with new theoretical developments will expand our understanding of nuclear structure and nuclear reactions that produce the elements of the periodic table and power the cosmos. The knowledge and understanding gained from FRIB will benefit a variety of applications including stockpile science, nuclear forensics, nonproliferation, nuclear energy, and nuclear medicine. LLNL is actively involved in a variety of basic and applied science activities related to FRIB. These activities are listed below and documented in the following sections: 1. FRIB Decay Station, 2. Isotope Harvesting, 3. Direct Reactions, 4. Surrogate Reactions, 5. Nuclear Structure and Collectivity, 6. Nuclear Fission, and 7. Nuclear Theory.
07 ISOTOPE AND RADIATION SOURCES↗
NorthStar Helium Cooling System. Final Report on LANL Contribution
From the beginning of NNSA support to the NorthStar development of a production facility for the medical isotope Molybdenum-99 (Mo99), LANL has been responsible for the design and testing of a target and its cooling. The target is comprised of a stack of Mo100 disks separated by coolant flow gaps between the disks and between the first disk and a housing window, which separates the target and its coolant from the vacuum of the beam line. The target, and therefore its cooling requirements, evolved steadily over the years of system development
07 ISOTOPE AND RADIATION SOURCES↗
Solvent Recovery and Management at the Savannah River Site H-Canyon Facility
NIOWAVE, Inc. is a domestic supplier of medical and industrial isotopes from uranium and radium. The Savannah River National laboratory (SRNL) is currently providing support to NIOWAVE, which plans to deploy a superconducting electron linear accelerator (LINAC) to fission uranium for Mo-99 production without the need for a nuclear reactor or HEU. The uranium from the Mo-99 production targets will be purified using a modified PUREX (Plutonium Uranium Reduction Extraction) solvent extraction process to recover the uranium in the product stream. The uranium will then be precipitated as an oxalate which is calcined to U 3 O 8 to fabricate pellets for new Mo-99 targets. In previous support provided to NIOWAVE, the SRNL demonstrated a solvent washing process to remove degradation products from the tributyl phosphate (TBP) solvent used in the modified PUREX process under development for uranium recovery. To supplement this technology demonstration, NIOWAVE requested the SRNL to provide summary information on the solvent recovery and management activities which are used at the Savannah River Site (SRS) H-Canyon facility. An existing reference document for the reprocessing of irradiated HEU fuels at the SRS was used as the primary reference for the solvent management activities; although, other reference documents were used to provide supplementary information. The information provided includes a brief summary of the solvent degradation issues which have been observed in the H-Canyon solvent extraction cycles and resulting process safety concerns. The solvent recovery processes for the three cycles of solvent extraction used in the H-Canyon were subsequently described including the process equipment which consists of the continuous and batch solvent washers, pumps, and tanks. A final section is provided on the monitoring and analysis of solvent quality based on the previous work performed at the SRNL for NIOWAVE and past research and development activities performed to support the solvent extraction processes in both the SRS F-Canyon and H-Canyon facilities.
07 ISOTOPE AND RADIATION SOURCES↗
Nuclear Forensics
Nuclear forensics is a key part of the nuclear security strategy for the United States and the international community. The NACS Division is central to the leadership role that LLNL has had in nuclear forensics over the past 25 years. Our current nuclear forensic program includes conducting R&D on provenance and attribution signatures, collaborating with international partners, training the next generation of nuclear forensic experts, developing test materials for verification and validation exercises, and providing expert advice to national and international policy makers. Key to our success in these areas has been the strong and continuing involvement in nuclear forensic casework obtained through law enforcement and intelligence channels as well as our outstanding analytical capabilities. NACS must continue to conduct forward-thinking R&D in nuclear forensics that supports operational programs and addresses intelligence gaps. To maintain leadership in nuclear forensics, we must attract, develop, and retain the best talent. The NNSA has a central leadership role in developing educational initiatives for nuclear forensics. In concert with the Glenn T. Seaborg Institute, the NACS Division will continue to participate in all nuclear forensic educational initiatives (undergraduate, graduate, postdoctoral) and incorporate LLNL’s D&I vision into its student and postdoc recruitment efforts. We will continue to build formal relationships with key academic partners and institutions with active and emerging nuclear forensic research interests. We will also strengthen relationships with NNSA DNN and SSAA funded university consortia (e.g. NSSC, ACE, CNEC, CVT, ETI, MTV), helping them conduct research of interest and relevance to nuclear forensics, while at the same time evaluating and recruiting promising talent from these programs.
07 ISOTOPE AND RADIATION SOURCES↗
Monte Carlo Simulations in Support of NorthStar Irradiation Facility Commissioning Procedure
NorthStar Medical Radioisotopes LLC is constructing an irradiation facility at which electron accelerators will induce photo-transmutation (i.e., neutron knockout) of molybdenum-100 (Mo-100) to produce medically useful Mo-99. The facility will house two high-intensity electron RhodotronTM accelerators developed by IBA Industrial. The nominal power of each Rhodotron is 125kW at 40 MeV beam energy. The production target is made of metallic molybdenum enriched with Mo-100 isotope. It will be irradiated by electron beams and will itself play a role in electron conversion to intense X-rays. A full description of the NorthStar target as well as the concept of radiation shielding of the facility can be found in our previous report. The NorthStar irradiation facility is under commissioning now. The goal of the present work is to support the commissioning process by: (1) Studying residual radiation and activation to minimize personnel exposure and inform radiation waste management; (2) Using computational fluid dynamics (CFD) of the irradiated target to ensure the facility design is safe and reliable; and (3) Helping to determine radiation protection requirements during operation. Monte Carlo simulations are used for the analyses. Most of the results are presented as 3D arrays representing spatial distribution of values across simulated geometries: radiation energy depositions, ambient doses, residual isotopes accumulated, and residual doses.
07 ISOTOPE AND RADIATION SOURCES↗
Revisions of ORNL 188 W Process Based on Nonradiological Experiments
Tungsten-188 is in widespread use in the 188 W(t 1/2 = 69 d)/ 188 Re(t 1/2 =16.9 h) biomedical generator. Oak Ridge National Laboratory (ORNL) has been providing this product to the world since 1999. At ORNL, 188 W is produced via irradiation in ORNL’s High Flux Isotope Reactor (HFIR). Enriched 186 W targets in the form of sintered metallic pellets or rings achieve a compact loading in the irradiation vessel, providing a high yield per unit target. The enrichment of the target is >90% 186 W and this isotope undergoes double neutron capture to produce the desired 188W product. While 188 W is produced by neutron bombardment, 191 Os(t 1/2 = 15.4 d) is simultaneously produced as a byproduct requiring separation from 188 W by post irradiation treatment. In the current processing pathway, the irradiated W metal pellets or rings are first converted into an oxide form of WO 3 by heating the irradiated W metal target at 750°C in a quartz reaction vessel inside a vertical furnace under a constant flow of air. During heating, W metal reacts with oxygen in the air to produce WO 3 , which is soluble in 6 M NaOH for later purification process. This oxidation process also converts 188 Os (the decay daughter of 188 W) and 191 Os (the irradiation produced byproduct) into OsO 4 , a highly volatile and toxic gas. The gaseous effluents driven from the quartz reaction vessel are passed through a scrubbing array to remove OsO 4 before the air is discharged from the process. This heterogeneous oxidation method simultaneously achieves two goals: 1). converting metal target to a soluble oxide form and 2). separating volatile OsO 4 away from the solid WO 3 product, although harmful 191 OsO 4 is unfavorable but being taken care of by the down road scrubbing array. In the past twenty years the existing OsO 4 scrubbing array served well in preventing OsO 4 from being released into the environment, until July of 2020 when a minor amount of 191 Os was found to have been released into the environment which resulted in a standby of building 4501 from July 2020 to February 2021.Since October 20 of 2020 a team of researchers from groups of RSTD and NEFD were organized to work for the following tasks: (1) Fully understand the root causes of the July incident of 191 Os release and create a redesigned 191 Os scrubbing array to eliminate the possibility of 191 Os release in future 188 W processes; (2) In Phase-1 tests, select a correct air (O 2 ) flow rate in 188 W process, that provides sufficient oxygen for the oxidation of tungsten metal, while still allowing sufficient resonance time for 191 Os removal by the scrubbers; (3) In Phase-2 tests, confirm the efficiency of the redesigned scrubbing array to absorb excessive amount of non-rad OsO 4 (generated from Os metal powder) at the selected air flow; (4) In Phase-3 tests, simulate the hot cell 188 W process by heating pressed non-rad W-Os pellets in a quartz vessel of new design and the new array under operation parameters selected in Phase-1 and -2; (5) Complete a new operation procedure for 188 W process in hot cell and a TM report as a summary of the Os Mitigation Project. This TM report summarizes the investigation on root causes from technical aspects in July 191 Os release and the correspondent improvement towards the redesigned 191 Os scrubbing system. The report presents the efforts made on selection of optimal operational parameter with the new scrubbing array and the quartz vessel of new design, based on experiment data obtained in Phase-1, -2 and -3 tests. Further renovations for 188 W process and additional improvement of W target treatment will also be discussed.
07 ISOTOPE AND RADIATION SOURCES↗
Light Weight Radioisotope Heater Unit User’s Guide
This user's guide provides an overview of Light Weight Radioisotope Heater Units (LWRHU), including aspects of its physical design and performance under normal operations. This guide also identifies the planning and execution involved in launching a nuclear payload. Physical characteristics, interfaces, and environmental characteristics of the LWRHU are discussed in detail. Information relating to project management interfaces and effort.
07 ISOTOPE AND RADIATION SOURCES↗
Technical Guidance on Use of the Linseis Vertical Dilatometer L75
Linseis vertical Dilatometer L75 thermal expansion equipment is a complete system which can be used for measuring change of the absolute length of a sample, determination of the thermal expansion coefficient (CTE), shrinkage, and sintering. The 238 Pu Supply Program is interested in re-establishing the capability to determine CTE and measuring the change of the absolute length of various 237 Np Al/cermet samples during heating. The change in length of the measured sample is recorded using a highly sensitive Linear Variable Differential Transformer (LVDT). The dilatometer is user-friendly and simple to operate which will allow technicians to be trained easily on its use. This equipment was designed to be used specifically for ceramics. It has a highly vacuum tight push rod dilatometer, a high-resolution inductive transducer using innovative and comprehensive temperature controls which provide excellent performance as a measurement system yielding high accuracy, reproducibility, and long-term stability.
07 ISOTOPE AND RADIATION SOURCES↗