Search NASA⌕ Search

SEARCH · Search NASA

Results for “RADIOACTIVE DATING”

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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

The whisper of a whimper of a bang: 2400 d of the Type Ia SN 2011fe reveals the decay of 55Fe

ABSTRACT We analyse new multifilter Hubble Space Telescope (HST) photometry of the normal Type Ia supernova (SN Ia) 2011fe out to ≈2400 d after maximum light, the latest observations to date of a SN Ia. We model the pseudo-bolometric light curve with a simple radioactive decay model and find energy input from both 57Co and 55Fe are needed to power the late-time luminosity. This is the first detection of 55Fe in a SN Ia. We consider potential sources of contamination such as a surviving companion star or delaying the deposition time-scale for 56Co positrons but these scenarios are ultimately disfavored. The relative isotopic abundances place direct constraints on the burning conditions experienced by the white dwarf (WD). Additionally, we place a conservative upper limit of <10−3 M⊙ on the synthesized mass of 44Ti. Only two classes of explosion models are currently consistent with all observations of SN 2011fe: (1) the delayed detonation of a low-ρc, near-MCh (1.2–1.3 M⊙) WD, or (2) a sub-MCh (1.0–1.1 M⊙) WD experiencing a thin-shell double detonation.

Astronomy & Astrophysics↗
NASA NTRS1980

I-Xe dating of Allende inclusions - Antiquity and fine structure

Two inclusions from the Allende meteorite exhibit multiple I-Xe isochrons corresponding to an age difference of 3.7 + or - 1.5 m.y. for their constituent minerals. Consequently, I-Xe dating can establish, independently of thermodynamic models, a partial sequence of formation for minerals that incorporated radioactive I-1290. Additionally, the results give an estimate of the cooling rate for the solar nebula when validity of thermodynamic models is assumed.

Zaikowski, A.↗
NASA NTRS1982

Radioactivities in returned lunar materials and in meteorites

Carbon-14 measurements were made for meteorites with a Van der Graaf accelerator. Accelerator C-14 dating improved the precision by a factor of ten, allowed the use of smaller sample sizes, and gave speedier results than C-14 dating with counters. A methodology for determining the terrestrial ages of several antarctic meteorites is described and the results are listed.

Fireman, E. L.↗
DOE OSTI2021

Effects of HZ-PAN Sorbent Irradiation on Kr Adsorption

Idaho National Laboratory (INL) has developed and studied an engineered form hydrogen mordenite in polyacrylonitrile matrix (HZ-PAN) for krypton (Kr) adsorption. Adsorption studies to date have successfully separated and captured Kr from carrier gas streams, but those studies have used non-radioactive gases for testing. However, if utilized in a used nuclear fuel (UNF) reprocessing facility, this sorbent will be exposed to the potential deleterious effects of radiation. This report explores Kr adsorption behavior on HZ PAN after the sorbent was exposed to gamma radiation. A batch of HZ-PAN was divided into five segments, a control segment that was not exposed to radiation, and the other four segments that were exposed to progressively increased levels of radiation dose, up to 5 MGy. Samples were then analyzed to determine total surface area as well as their capacity to capture Kr. This study reveals HZ PAN retains its initial surface area and Kr-capture capacity after radiation exposure, indicating viability for service in radioactive gases.

42 - ENGINEERING↗
DOE OSTI2022

FY2021 Savannah River Site Composite Analysis Annual Summary Review

This document provides the Department of Energy (DOE) Order 435.1 and its manual, Radioactive Waste Management (DOE 2021a, 2021b) required Annual Review for the Savannah River Site (SRS) Composite Analysis (CA). Progress made to-date toward addressing the secondary issue from the LFRG review of the 2010 SRS CA has focused primarily upon inventory estimate improvements. Inventory impacts dose in a linear fashion and reduces the uncertainty with the CA conclusions. Maintenance items are addressed, as funding allows, based on the relative risk associated with meeting the performance objectives. Currently, there is minimal risk in exceeding the DOE 100 mrem/yr CA primary dose limit or the DOE 30 mrem/yr dose constraint (administrative limit).

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

Industrial Stormwater Pollution Prevention Plan (SWPPP) for SNL/CA Reporting Year 2022-2023

The Sandia National Laboratories, California (SNL/CA) site comprises approximately 410 acres and is located in the eastern portion of Livermore, Alameda County, California. The property is owned by the United States Department of Energy and is being managed and operated by National Technology & Engineering Solutions of Sandia, LLC. The facility location is shown on the Site Map(s) in Appendix A. This Stormwater Pollution Prevention Plan (SWPPP) is designed to comply with California’s General Permit for Stormwater Discharges Associated with Industrial Activities (General Permit) Order No. 2015-0122-DWQ (NPDES No. CAS000001) issued by the State Water Resources Control Board (State Water Board) (Ref. 6.1). This SWPPP has been prepared following the SWPPP Template provided on the California Stormwater Quality Association Stormwater Best Management Practice Handbook Portal: Industrial and Commercial (CASQA 2014). In accordance with the General Permit, Section X.A, this SWPPP contains the following required elements: Facility Name and Contact Information; Site Map; List of Significant Industrial Materials; Description of Potential Pollution Sources; Assessment of Potential Pollutant Sources; Minimum BMPs; Advanced BMPs, if applicable; Monitoring Implementation Plan (MIP); Annual Comprehensive Facility Compliance Evaluation (Annual Evaluation); and, Date that SWPPP was Initially Prepared and the Date of Each SWPPP Amendment, if Applicable.

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

The Utility of Waste Tank Historical Reviews in Bulk Waste Removal Operations at the Savannah River Site – 25271

SRMC is actively working to remove, treat, and dispose radioactive waste generated by the separation facilities at SRS since their initial operations in the 1950s. The separation facilities at SRS have produced nuclear materials for a variety of purposes, particularly national defense, and continue to support the disposition of spent fuel through the Accelerated Basin Deinventory program. In almost 70 years of operation, nearly 625,000 m3 (165 million gallons) of radioactive waste have been generated and transferred to the tank farm facilities at SRS [1]. As a result of volume reduction (e.g., evaporation) and waste solidification (e.g., vitrification), approximately 127,000 m3 (33.5 million gallons) of material remain as of June 30, 2024 [2]. This liquid waste has since been stored in 51 large underground waste tanks present on the site. These waste tanks may contain up to 4,921 m3 (1.3 million gallons) of radioactive waste each in the form of saltcake or sludge. SRMC’s contract is to treat and dispose of this waste, clean the tanks, and operationally close them. To date, 8 of the 51 waste tanks have been operationally closed. Waste retrieval and tank closure activities are ongoing in an additional 17 tanks through either operations in the field or in design [3].

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

The Sporadic History of Rubidium and its Role in Corrosion of Steel Related to Nuclear Material Storage

The influence of rubidium (Rb), both in its metallic and oxidized states, on the corrosion resistance of steels has direct relevance to the storage of radioactive Kr-85 containing nuclear materials. Kr-85 undergoes a ß-decay to generate stable, metallic Rb. The literature to date is sparse, contained primarily in company reports and divisive as to whether Rb metal, or its oxides, can lead to corrosion of steel materials. In both the direct storage of Kr-85 and used nuclear fuel that will contain Kr-85, if Rb is corrosive then continual decay of the Kr-85 will generate an increasingly corrosive environment for the steel canister it is stored in. This review was written to consolidate the known data to date on Rb corrosion of steels to identify consistencies, contradictions and remaining gaps in our understanding of the Rb : steel system.

krypton, corrosion, steel, Rubidium↗
DOE OSTI2023

Characterization of Salt Waste Processing Facility August 2022 Tank 201 sample

Two Salt Waste Processing Facility (SWPF) Tank 201 samples were collected from the replacement of the decontaminated salt solution (DSS) coalescer at different times; one in December of 2021 and the other in August 2022. The December 2021 sample was collected after nitric and water flushing of the DSS Coalescer. The Aug 2022 sample was collected after water flushing only. The December 2021 Tank 201 solids were previously characterized and documented. SWPF requested the characterization of the August 2022 Tank 201 sample, and the comparison of the characterization results for these two Tank 201 solids collected at different dates.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

FY2020 Savannah River Site Composite Analysis Annual Summary Review

This document provides the Department of Energy (DOE) Order 435.1 and its manual, Radioactive Waste Management (DOE 2021a, 2021b) required Annual Review for the Savannah River Site (SRS) Composite Analysis (CA). Progress made to-date toward addressing the secondary issue from the LFRG review of the 2010 SRS CA has focused primarily upon inventory estimate improvements. Inventory impacts dose in a linear fashion and reduces the uncertainty with the CA conclusions. Maintenance items are addressed, as funding allows, based on the relative risk associated with meeting the performance objectives. Currently, there is minimal risk in exceeding the DOE 100 mrem/yr CA primary dose limit or the DOE 30 mrem/yr dose constraint (administrative limit). Proposed activities, discoveries, new information and changes potentially affecting the 2010 SRS CA are documented in this and earlier Annual Summary reports, and a consolidated list of changes since the 2010 CA is documented in this report. The impact to the CA of changes arising from updated performance assessment (PA) baselines [i.e., Saltstone Disposal Facility (SDF), E-Area Low-Level Waste Facility (ELLWF), and F & H Tank Farm (FTF & HTF) closures] is expected to be minor for the following reasons: The primary contributors to the SRS CA dose impact at the Upper Three Runs (UTR) point of assessment (POA) are the H-Canyon and Mixed Waste Management Facility (MWMF), contributing 68% and 9%, respectively, to the dose impact at that POA. The combined contribution to the UTR dose impact from all PA’s (SDF, ELLWF, FTF and HTF) is ~2% of this total. The 2010 SRS CA model validation performed indicates that the CA projected dose, while generally conservative, provides a reasonable representation of the maximum annual doses. Doses evaluated are well below the SRS established 15 mrem/yr administrative limit (Crapse et al. 2011). Based on the assessment presented within this annual review and collective engineering judgement, the conclusions of the 2010 SRS CA remain valid and there is reasonable assurance that SRS will meet the performance objectives delineated in DOE Manual 435.1-1. The 2010 SRS CA should be updated to incorporate PA changes, proposed changes to inventories and sources and model improvements accumulated since the 2010 CA. The timing will be dependent on the completion of the ongoing E-Area PA revision.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Electrolytically Assisted Surface Decontamination (EASD{sup TM}) for POCO Operations - 20282

NNL in collaboration with C-Tech Innovation Ltd and Sellafield Ltd has been exploring innovative technologies to enable a significant reduction of radiological hazards within facilities during the Post Operational Clean Out (POCO) phase of a nuclear plant's life cycle. Reducing the hazard by effectively decontaminating plants in-situ during POCO delivers huge cost reductions for future decommissioning operations. These cost reduction benefits are realized by reducing the number and complexity of remote operations as well as lowering the long-term waste disposal costs. Whilst chemical decontamination can achieve the desired level of decontamination, applying aggressive chemical reagents is hazardous, potentially difficult to control and requires there to be complimentary effluent treatment and waste routes. This work has aimed to develop flexible and controllable decontamination processes which could be operated without the additional complexity and issues associated with chemical decontamination. The processes needed to be relatively fast and effective to minimize the time operators would spend in an active area. In addition, there was a driver to produce decontamination methodologies which generated a secondary waste compatible with current routes and which takes advantage of current waste capacity. The strategy therefore was to come up with a solution that works with, rather than against, the science and engineering behind process plants at Sellafield. Electrolytically Assisted Surface Decontamination (EASD{sup TM}) is an innovative electrochemical decontamination process (developed by NNL and C-Tech Innovation Ltd) that can remove activity from contaminated metal in very short time periods. Application of the patented electric waveform to the surface when treating contaminated metal with nitric acid has been shown to significantly enhance the decontamination performance. When compared to proposed baseline washout procedures at Sellafield, the only change to the process is the applied electrical waveform which is temporary and controllable. The current causes dissolution of the metal surface being decontaminated which leads to activity transferring from the plant item into the nitric acid effluent stream. This innovation has the potential to transform the POCO process and allow a nitric acid based washout approach to deliver POCO quickly and cost effectively within the existing infrastructure. Several devices have now been designed that incorporate this EASD{sup TM} technology and enable the decontamination process to be applied to a range items commonly identified as being contaminated during nuclear decommissioning programmes such as pipework, tanks and hotspots of walls/floors. Inactive and active laboratory-scale testing has been completed using both simulated and 'real-life' contaminated (low level waste) metallic items retrieved from different nuclear sites. Active trials demonstrated that contaminated items could be treated to free release levels within minutes. Engineering scale tests are currently being performed, with guidance from Sellafield's system engineers and plant managers, to provide the necessary re-assurance the designed devices could be successfully deployed in an on-plant scenario. The final stage of this development work is to carry out an active demonstration of the decontamination technology on Thorp at Sellafield. This paper aims to highlight progress made to date with the EASD{sup TM} technology and, more specifically, the development of an in-situ decontamination device for deployment within radioactive pipework. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2026

Creating high-precision reference gas standards of 85Kr for groundwater age-dating

Absolute gas counting (AGC) was applied to two gas blends of 85Kr in argon-methane (P10) counting gas to establish a high-precision specific activity (Bq/cm3) reference value for characterizing 85Kr detection efficiency for groundwater age dating measurements. The AGC or length-compensated technique has been utilized by the metrology community for decades and is an accepted method for developing radioactive gas standards. The AGC capability at Pacific Northwest National Laboratory (PNNL) uses a set of nine unequal-length proportional counters with precisely-measured internal volumes, and a gas loading system with high-precision pressure and temperature sensors. A series of AGC measurements were collected at multiple pressures to determine the inverse pressure relationship (1/P) for 85Kr and define a wall-effect correction that accounts for events decaying into the detector wall and not depositing sufficient energy in the gas to be detected. In addition to the wall-effect, two additional corrections were evaluated and are discussed in detail. Specifically, the threshold effect which accounts for events deposited below the analysis threshold and a detection efficiency as a function of detector volume effect that was observed during analysis. A robust uncertainty model was developed using the Guide to the expression of Uncertainty in Measurements (GUM) approach. The combination of carefully scrutinized correction factors, precise measurements of pressure, temperature and detector volume, and robust counting statistics resulted in the determination of high-precision specific activity values with 0.50% or less total combined uncertainty for two Kr-in-P10 reference gas standards (KP10) that will enable new groundwater age-dating measurements at PNNL.

Kr-85↗
DOE OSTI2020

Peer Review Comments on the Authorized Limits Technical Document (OREM-19-2573) for Disposal of Waste Containing Residual Radioactive Material at the U.S. Department of Energy Industrial Landfill IV, Y-12 National Security Complex, Oak Ridge, Tennessee

Argonne National Laboratory is assigned responsibility by DOE/EM-4 to conduct a peer review of the proposed Authorized Limits (ALs) for disposal of waste containing residual radioactive material at the U.S. Department of Energy (DOE) Industrial Landfill IV, Y-12 National Security Complex, Oak Ridge, Tennessee. The ALs document package (Document Number OREM-19-2573, dated May 2020) was sent to Argonne by DOE on June 1, 2020 (Oak Ridge 2020a). Argonne started the review immediately and held several BlueJeans meetings with Oak Ridge and DOE to discuss review comments. The first BlueJeans meeting was June 17, 2020. Oak Ridge presented a briefing of the AL package, followed by discussion of the assumptions, methodology, and parameters used in the analysis. A follow-up BlueJeans meeting was held on June 24, 2020, at which Argonne presented both general and specific review comments in PowerPoint slides. This set of slides - Review Comments on the “Authorized Limits for Disposal of Waste Containing Residual Radioactive Material at DOE Industrial Landfill IV, Y-12 National Security Complex, Oak Ridge, Tennessee” - was then emailed to Oak Ridge and DOE after the BlueJeans meeting on June 24, 2020. A PDF version of this slide set is included as Appendix A.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2026

Developing a Process for Collaboration-Based Siting of a Federal Consolidated Interim Storage Facility in the United States: Learning from Communities Living with Legacy Waste

In June of 2023, the U.S. Department of Energy (DOE), Office of Nuclear Energy (NE) announced the selection of its Collaboration-Based Siting (CBS) Consortia, a group of 12 awardees, including the Consortium for Risk Evaluation with Stakeholder Participation (CRESP) (led by Vanderbilt University) to assist DOE-NE with the development of its process for siting a federal consolidated interim storage facility (FCISF) for spent nuclear fuel (SNF) storage. At this time, DOE NE is not soliciting interested host communities, rather the CBS Consortia are tasked with in-depth engagement, mutual learning, and capacity building to provide DOE NE with feedback on the CBS process. CRESP’s objective is to engage communities in two regions (the Pacific Northwest and the Southeast) with sites currently storing defense- and research-related SNF to foster learning concerning the best and worst practices in community participation in risk-informed decision making. This includes learning from existing structures for public input in radioactive waste management decision making [e.g. citizen advisory boards (CABs)] and other local parties about how to build and sustain trust among the parties. CRESP has been working to engage stakeholders and Tribes surrounding two DOE sites historically differing in receptiveness to engaging with DOE and trusting in DOE to accomplish its missions. CRESP’s approach to date has consisted of (1) engaging voluntarily members and former members of the DOE Office of Environmental Management’s CABs to develop a mutual understanding of their perspectives, values, and experiences related to risk and participatory decision making; (2) engaging members of those communities that would likely be part of any radioactive waste management discussions and who may provide valuable feedback for the development of the CBS process; and in the longer term, (3) engaging communities to foster knowledge sharing on understanding and definitions of risk and how risk is factored into community decision making. Our emphasis is to identify opportunities for improving risk communication frameworks, strategies, and decision making. The selection of a future FCISF site is likely to result in the creation of a structure similar to a CAB composed of members of the local community. We anticipate that these insights can help DOE NE learn from existing participatory risk communication structures in place at sites storing defenseor research-related SNF to understand best practices for fostering enduring and participatory relationships with future CABs. Within this paper, we (1) describe CRESP’s overall approach to assisting DOE NE with maturing the CBS process; (2) present a summary of preliminary phase 1 project results, including the development of a body of knowledge (describing available resources to support community engagement, risk communica tion, and participatory decision making) and community ecosystem information (leveraging demographic, social, economic, and environmental attribute mapping and advanced sentiment analysis of social media data); and (3) based on these results, provide observations for future research opportunities to support the development of CBS processes for radioactive waste management facilities, generally.

collaboration-based siting↗
DOE OSTI2021

A novel experimental system for the KDK measurement of the 40 K decay scheme relevant for rare event searches

Potassium-40 ( 40 K) is a long-lived, naturally occurring radioactive isotope. The decay products are prominent backgrounds for many rare event searches, including those involving NaI-based scintillators. 40 K also plays a role in geochronological dating techniques. The branching ratio of the electron capture directly to the ground state of argon-40 has never been measured, which can cause difficulty in interpretingcertain results or can lead to lack of precision depending on the field and analysis technique. Additionally, the KDK (Potassium (K) Decay (DK)) collaboration is measuring this decay. A composite method has a silicon drift detector with an enriched, thermally deposited 40 K source inside the Modular Total Absorption Spectrometer. This setup has been characterized in terms of energy calibration, gamma tagging efficiency, live time and false negatives and positives. A complementary, homogeneous, method is also discussed; it employs a KSr 2 I 5 :Eu scintillator as source and detector.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗