Engineering Papers⌕ Search

SEARCH · Engineering Papers

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 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Commissioning and field tests of a van-mounted system for the detection of radioactive sources and Special Nuclear Material

MODES SNM project aimed to carry out technical research in order to develop a prototype for a mobile, modular detection system for radioactive sources and Special Nuclear Materials (SNM). Its main goal was to deliver a tested prototype of a modular mobile system capable of passively detecting weak or shielded radioactive sources with accuracy higher than that of currently available systems. By the end of the project all the objectives have been successfully achieved. Results from the laboratory commissioning and the field tests will be presented. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Network Time Synchronization of the Readout Electronics for a New Radioactive Gas Detection System

In systems with multiple radiation detectors, time synchronization of the data collected from different detectors is essential to reconstruct multi-detector events such as scattering and coincidences. In cases where the number of detectors exceeds the readout channels in a single data acquisition electronics module, multiple modules have to be synchronized, which is traditionally accomplished by distributing clocks and triggers via dedicated connections. To eliminate this added cabling complexity in the case of a new radioactive gas detection system prototype under development at the French Atomic Energy Commission, we implemented time synchronization between multiple XIA Pixie-Net detector readout modules through the existing Ethernet network, based on the IEEE 1588 precision time protocol. The detector system is dedicated to the measurement of radioactive gases at low activity and consists of eight large silicon pixels and two NaI(Tl) detectors, instrumented with a total of three 4-channel Pixie-Net modules. Detecting NaI(Tl)/silicon coincidences will make it possible to identify each radioisotope present in the sample. To allow these identifications at low activities, the Pixie-Net modules must be synchronized to a precision well below the targeted coincidence window of 500-1000 ns. Being equipped with an Ethernet PHY compatible with IEEE 1588 and synchronous Ethernet that outputs a locally generated but system-wide synchronized clock, the Pixie-Net can operate its analog to digital converters and digital processing circuitry with that clock and match time stamps for captured data across the three modules. Depending on the network configuration and synchronization method, the implementation is capable to achieve timing precisions between 300 ns and 200 ps.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2014

SU-E-T-388: Estimating the Radioactivity Inventory of a Cyclotron Based Pencil Beam Proton Therapy Facility

Purpose: Parts of the cyclotron and energy degrader are incidentally activated by protons lost during the acceleration and transport of protons for radiation therapy. An understanding of the radioactive material inventory is needed when regulatory requirements are assessed. Methods: First, the tumor dose and volume is used to determine the required energy deposition. For spot scanning, the tumor length along the beam path determines the number of required energy layers. For each energy layer the energy deposition per proton can be calculated from the residual proton range within the tumor. Assuming a typical layer weighting, an effective energy deposition per proton can then be calculated. The total number of required protons and the number of protons per energy layer can then be calculated. For each energy layer, proton losses in the energy degrader are calculated separately since its transmission efficiency, and hence the amount of protons lost, is energy dependent. The degrader efficiency also determines the number of protons requested from the cyclotron. The cyclotron extraction efficiency allows a calculation of the proton losses within the cyclotron. The saturation activity induced in the cyclotron and the degrader is equal to the production rate R for isotopes whose half-life is shorter that the projected cyclotron life time. R can be calculated from the proton loss rate and published production cross sections. Results: About 1/3 of the saturation activity is produced in the cyclotron and 2/3 in the energy degrader. For a projected case mix and a patient load of 1100 fractions per week at 1.8 Gy per fraction a combined activity of 180 mCi was estimated at saturation. Conclusion: Calculations were used to support to application of a radioactive materials license for the possession of 200 mCi of activity for isotopes with atomic numbers ranging from 1-83.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2016

SU-F-J-09: Radioactive Seed Localization for Breast Lumpectomy - Towards Optimization

Purpose: The aim of this work is to propose a method to optimize radioactive source localization (RSL) for non-palpable breast cancer surgery. RSL is commonly used as a guiding technique during surgery for excision of non-palpable tumors. A collimated hand-held detector is used to localize radioactive sources implanted in tumors. Incisions made by the surgeon are based on maximum observed detector counts, and tumors are subsequently resected based on an arbitrary estimate of the counts expected at the surgical margin boundary. This work focuses on building a framework to predict detector counts expected throughout the procedure to improve surgical margins. Methods: A gamma detection system called the Neoprobe GDS was used for this work. The probe consists of a cesium zinc telluride crystal and a collimator. For this work, an I-125 Best Medical model 2301 source was used. The source was placed in three different phantoms, a PMMA, a Breast (25%- glandular tissue/75%- adipose tissue) and a Breast (75-25) phantom with a backscatter thickness of 6 cm. Counts detected by the probe were recorded with varying amounts of phantom thicknesses placed on top of the source. A calibration curve was generated using MATLAB based on the counts recorded for the calibration dataset acquired with the PMMA phantom. Results: The observed detector counts data used as the validation set was accurately predicted to within ±3.2%, ±6.9%, ±8.4% for the PMMA, Breast (75-25), Breast (25–75) phantom respectively. The average difference between predicted and observed counts was −0.4%, 2.4%, 1.4% with a standard deviation of 1.2 %, 1.8%, 3.4% for the PMMA, Breast (75-25), Breast (25–75) phantom respectively. Conclusion: The results of this work provide a basis for characterization of a detector used for RSL. Counts were predicted to within ±9% for three different phantoms without the application of a density correction factor.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Cold reaction valleys in the radioactive decay of superheavy {sup 286}112, {sup 292}114, and {sup 296}116 nuclei

Cold reaction valleys in the radioactive decay of superheavy nuclei {sup 286}112, {sup 292}114, and {sup 296}116 are studied taking Coulomb and Proximity Potential as the interacting barrier. It is found that in addition to alpha particle, {sup 8}Be, {sup 14}C, {sup 28}Mg, {sup 34}Si, {sup 50}Ca, etc. are optimal cases of cluster radioactivity since they lie in the cold valleys. Two other regions of deep minima centered on {sup 208}Pb and {sup 132}Sn are also found. Within our Coulomb and Proximity Potential Model half-life times and other characteristics such as barrier penetrability, decay constant for clusters ranging from alpha particle to {sup 68}Ni are calculated. The computed alpha half-lives match with the values calculated using Viola-Seaborg-Sobiczewski systematics. The clusters {sup 8}Be and {sup 14}C are found to be most probable for emission with T{sub 1/2} < 10{sup 30} s. The alpha-decay chains of the three superheavy nuclei are also studied. The computed alpha-decay half-lives are compared with the values predicted by Generalized Liquid Drop Model and they are found to match reasonably well.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, we detail the results from screening 286 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2013

Considerations of human intrusion in U.S. programs for deep geologic disposal of radioactive waste

Regulations in the United States that govern the permanent disposal of spent nuclear fuel and high-level radioactive waste in deep geologic repositories require the explicit consideration of hypothetical future human intrusions that disrupt the waste. Specific regulatory requirements regarding the consideration of human intrusion differ in the two sets of regulations currently in effect in the United States; one defined by the Environmental Protection Agency's 40 Code of Federal Regulations part 197, applied only to the formerly proposed geologic repository at Yucca Mountain, Nevada, and the other defined by the Environmental Protection Agency s 40 Code of Federal Regulations part 191, applied to the Waste Isolation Pilot Plant in New Mexico and potentially applicable to any repository for spent nuclear fuel and high-level radioactive waste in the United States other than the proposed repository at Yucca Mountain. This report reviews the regulatory requirements relevant to human intrusion and the approaches taken by the Department of Energy to demonstrating compliance with those requirements.

Swift, Peter N.↗
DOE OSTI2016

Complete Non-Radioactive Operability Tests for Cladding Hull Chlorination

Non-radioactive operability tests were made to test the metal chlorination reactor and condenser and their accessories using batch chlorinations of non-radioactive cladding samples and to identify optimum operating practices and components that need further modifications prior to installation of the equipment into the hot cell for tests on actual used nuclear fuel (UNF) cladding. The operability tests included (1) modifications to provide the desired heating and reactor temperature profile; and (2) three batch chlorination tests using, respectively, 100, 250, and 500 g of cladding. During the batch chlorinations, metal corrosion of the equipment was assessed, pressurization of the gas inlet was examined and the best method for maintaining solid salt product transfer through the condenser was determined. Also, additional accessing equipment for collection of residual ash and positioning of the unit within the hot cell were identified, designed, and are being fabricated.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

New research discovery may mean less radioactive contamination, safer nuclear power plants

Murph has now made another nanoparticle breakthrough that could benefit various work environments such as nuclear power plants. Murph and her team have created nanoparticle treated stainless steel filters that are capable to capturing radioactive vapor materials. Just like air filters capture dust and dirt, these filters are capable of capturing large amounts of radioactive vapors. The new research may one day mean that nuclear power plant workers, and other workers in related fields, will have a safer working environment.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2018

Radioactive aerosols training

An introduction to radioactive aerosols will be presented in this class. There will be a specific focus on transuranic materials, typical to those used in operations at Los Alamos. The uptake of radioactive aerosols is affected by the physical characteristics of the airborne material, the behavior of the aerosol in air (or gas), and the interaction of the material with the worker. Aerosol behavior in the radiological workplace will influence filtration, release control, and dose considerations. This course will review the basics of aerosol technology, distinguishing between the classical (Newtonian) and molecular (quantized) regimes. Particles from about 1 to 10 microns (diameter) are described by classical physics, but particles from about 0.01 to 0.3 microns must be understood through modern molecular theory (i.e. Einstein, 1905). The class will discuss relevant LANL accidents that involved aerosol releases from the years 1971, 1994, 2000, 2003 and 2005.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2019

Remediation Report for TA-53 P-Rad Radioactive Liquid Spill

Following several soil excavations, EPC-ES and DESHF-LFO finds that the residual radioactive materials associated with the spill area within AOC 53-013 at TA53 are below the 25 mrem/yr remediation criteria set for cleanup of the radioactive spill at TA-53.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Study of Neutron-Induced Stable and Radioactive Nuclides in a Post Detonation Urban Environment

In the event of a nuclear detonation in an urban environment, response time for triage by first responders, and forensic sample collection are of the utmost importance. When it comes to response planning, decision makers within the government need to have the most up-to-date information regarding several quantities of interest so that the maximum amount of lives can be saved. Quantities of interest in a post-detonation scenario include the spatial distribution of neutron-induced stable and radioactive isotopes in the environment, fallout patterns, blast and re damage zones [1]. The UMPRINDER toolkit is developed to calculate the prompt neutron-induced stable and radioactive isotopes in the surrounding environment in a nuclear forensics post-detonation scenario. The distribution of these isotopes in the environment can be used to provide guidance in determining best routes for first responders in order to minimize dose, debris sample collection routes for subsequent radiochemical analysis, and provide initial radionuclide inventories to fallout codes in order to improve fallout zone fidelity. Other methods have approached isotope transmutation on unstructured mesh for the fusion community concerning shutdown dose rates associated with fusion reactors. UMPRINDER is the first method to be focused on calculating some of the quantities of interest for the nuclear forensics and weapon effects communities.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2021

Boson Fermion Nucleus Explanation for Violation of Parity in the Radioactive Decay of Cobalt-60: Monograph #12

In 1957, Chien-Shuing Wu subjected cobalt-60 to supercooled temperatures and a strong magnetic field while measuring radioactive decay. This experiment showed violation of parity— a long-held, fundamental precept in physics stating that nuclear radioactive-decay emission flux will not vary in the solid angle about the nucleus. During Wu’s experiment, beta particles (electrons) exhibited asymmetry, preferentially exiting the cobalt-60 nuclei in the polar region opposite the applied magnetic field. Gamma-ray emissions were anisotropic, preferring to exit the nucleus around the equatorial region. The boson fermion nucleus (BFN) explains the origins of these observed phenomena, where the nuclear structure is pinned in the strong magnetic field with minimal motion in supercooled conditions, while beta particles and gamma rays are emitted from specific locations within the nuclear structure.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Remote Detection of Radioactive Materials Using Long Wavelength Infrared Laser Driven Avalanche Breakdown [Slides]

The yearly goals of the "Remote Detection of Radioactive Materials Using Long Wavelength Infrared Laser Driven Avalanche Breakdown" experiment are broken into two parts. Year 1: Perform proof-of-concept scaling experiments for detection of radioactive materials at 10m standoff distance, characterizing avalanche breakdowns with the 9.2μm long pulse beam line and optimizing diagnostics. Years 2-3: Extend technique to 30m detection distance, characterizing the effect of long propagation paths on sensitivity, improving diagnostic sensitivity and resolution, and characterizing the effects of turbulence and aerosols.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2022

Capability Needs for Irradiated and Radioactive Materials Research (Ad hoc Committee Summary Report)

It is essential for the U.S. nuclear energy community to have access to world-leading equipment suitable for conducting research on both nuclear fuels and structural materials, including neutron irradiated–and therefore activated–materials. To address future research infrastructure requirements to support the DOE-NE mission, the Office of Reactor Fleet and Advanced Reactor Deployment established an ad hoc committee to gather information on potential capability gaps for radioactive materials and radiation effects research. This document summarizes the discussions of the committee addressing the high-level challenges in irradiated and radioactive materials research and the capabilities needed to address these challenges. After considering the various needs, the committee agreed on the four top-level targets and priority capability gaps.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2025

Development of a Helical Closure for Radioactive Material Shipping Packages

Radioactive Material (RAM) Packagings Used to transport radioactive material • Weapons components • Medical isotopes • Spent nuclear fuel • Etc. • Packages must adhere to 10 CFR 71 which drive to NUREGs, ASME codes, etc. • Transport Index (A2 values) determine if a package is Type A, Type AF, Type B, Type B(U)F

Housley, William M. [Savannah River National Labor↗
DOE OSTI2026

Radioactivity-in-materials lead for nEXO (Final Scientific Report)

Abstract, introduction, and summary of work completed and products produced by DOE award SC002466. Primary products were six peer-reviewed publications and two PhD theses. This award also supported the operation of an underground HPGe detector and several radioassay measurements: one in a stand alone publication in Phys. Rev. C and the others in an upcoming nEXO radioassay summary paper. The nEXO collaboration aims to demonstrate the Majorana nature of the neutrino by observing the neutrinoless double-beta decay of 136 Xe with a next-generation experiment. The University of Kentucky nEXO group (UKY) operates a world-leading ultra-low-background γ-ray spectrometer as part of the nEXO radioactive background control R&D effort. The nEXO project is a proposed ton-scale neutrinoless double-beta decay experiment. The UKY PI is leading the radioactivity content assessment for all materials required by the nEXO project. As a subset of this task, UKY is also responsible for project-wide management of all low-background γ-ray spectrometry measurements; material assays with these types of instruments, together with ICP-MS, neutron-activation-analysis, and α-spectrometry, are critical to ensuring that the nEXO project can achieve its design sensitivity

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Comparative Uptake Patterns of Radioactive Iodine and [18F]-Fluorodeoxyglucose (FDG) in Metastatic Differentiated Thyroid Cancers

Background: Metastatic differentiated thyroid cancer (DTC) represents a molecularly heterogeneous group of cancers with varying radioactive iodine (RAI) and [ 18 F]-fluorodeoxyglucose (FDG) uptake patterns potentially correlated with the degree of de-differentiation through the so-called “flip-flop” phenomenon. However, it is unknown if RAI and FDG uptake patterns correlate with molecular status or metastatic site. Materials and Methods: A retrospective analysis of metastatic DTC patients (n = 46) with radioactive 131-iodine whole body scan (WBS) and FDG-PET imaging between 2008 and 2022 was performed. The inclusion criteria included accessible FDG-PET and WBS studies within 1 year of each other. Studies were interpreted by two blinded radiologists for iodine or FDG uptake in extrathyroidal sites including lungs, lymph nodes, and bone. Cases were stratified by BRAF V600E mutation status, histology, and a combination of tumor genotype and histology. The data were analyzed by McNemar’s Chi-square test. Results: Lung metastasis FDG uptake was significantly more common than iodine uptake (WBS: 52%, FDG: 84%, p = 0.04), but no significant differences were found for lymph or bone metastases. Lung metastasis FDG uptake was significantly more prevalent in the papillary pattern sub-cohort (WBS: 37%, FDG: 89%, p = 0.02) than the follicular pattern sub-cohort (WBS: 75%, FDG: 75%, p = 1.00). Similarly, BRAF V600E+ tumors with lung metastases also demonstrated a preponderance of FDG uptake (WBS: 29%, FDG: 93%, p = 0.02) than BRAF V600E- tumors (WBS: 83%, FDG: 83%, p = 1.00) with lung metastases. Papillary histology featured higher FDG uptake in lung metastasis (WBS: 39%, FDG: 89%, p = 0.03) compared with follicular histology (WBS: 69%, FDG: 77%, p = 1.00). Patients with papillary pattern disease, BRAF V600E+ mutation, or papillary histology had reduced agreement between both modalities in uptake at all metastatic sites compared with those with follicular pattern disease, BRAF V600E- mutation, or follicular histology. Low agreement in lymph node uptake was observed in all patients irrespective of molecular status or histology. Conclusions: The pattern of FDG-PET and radioiodine uptake is dependent on molecular status and metastatic site, with those with papillary histology or BRAF V600E+ mutation featuring increased FDG uptake in distant metastasis. Further study with an expanded cohort may identify which patients may benefit from specific imaging modalities to recognize and surveil metastases.

60 APPLIED LIFE SCIENCES↗