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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.

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At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

A New Manufacturing Method of Bentonite Pellets as a Gap Filling Material for HLW Repository - 16110

In high-level waste (HLW) repositories in Japan, there is a need to properly deal with gaps that surround buffers made of bentonite-based material, which are inevitably generated during construction. Bentonite pellets are thought to be a candidate material for filling these gaps. To fill the gaps densely in order to ensure desired buffer quality, high-density pellets with spherical shape would be suitable, and we have developed a new method for manufacturing such bentonite pellets, which is different from conventional methods. The new method first produces spherical pellets by extrusion and spheronization by alternately using two commercially available pelletizing machines. Then, the pellets, which do not have a very high density because of their water content, are turned into high-density ones using dry shrinkage. For typical Japanese sodium bentonite, we confirmed that spherical pellets can be manufactured when the water content is relatively high within the range of 25 to 30%. We observed that proper dry shrinkage enables the wet spherical pellets with a low density of about 1,500 kg/m{sup 3} to turn into ones with a high dry density of about 2,000 kg/m{sup 3} . Drying slowly causes the proper dry shrinkage. We performed simple laboratory tests to evaluate the filling performance of pellets produced by the new manufacturing method. The maximum filling density obtained was 1,540 kg/m{sup 3} when large (20-mm diameter) and small (1-mm diameter) pellets were mixed in the proportion of 60 % to 40 %, which is considerably higher than the previously reported maximum filling density in Japan, which was about 1,300 kg/m{sup 3}. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Sorption and Transport Behavior of {sup 137}Cs, {sup 90}Sr, and {sup 99}Tc on Geological Media in Radioactive Waste Repository, South Korea - 16112

Sorption experiments and a behavior investigation for the radionuclides {sup 137}Cs, {sup 90}Sr, and {sup 99}Tc were conducted using groundwater and solid materials (mud-stone and sandstone) sampled from the Wolsong low- and intermediate-level radioactive waste repository at Gyeongju, Korea. After experiments involving batch sorption, diffusion, and a flow-through column, distribution coefficients (K{sub d}) of the radionuclides were obtained, and sorption properties for each radionuclide were analyzed. Increasing K{sub d} values were observed in the sequence {sup 137}Cs, {sup 90}Sr, and {sup 99}Tc regardless of the geological media tested. For all sorbing radionuclides, K{sub d} values for the mud-stone were observed to be higher than those for sandstone regardless of the groundwater. These higher K{sub d} values are the result of higher levels of total organic carbon in the mud-stone than were present in the sandstone. In addition, the chlorite, kaolinite, and montmorillonite contents in the mud-stone also were higher than in the sandstone. The mineralogical composition of the solid materials was observed to be important in the sorption of sorbing radionuclides. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Update on Construction Planning for the Bulgarian Low and Short-Lived Intermediate Level Radioactive Waste Repository - 16159

The Bulgarian State Enterprise for Radioactive Waste Management (SERAW) is planning the construction of a near-surface repository for low and short-lived inter-mediate level radioactive waste, the National Disposal Facility (NDF), at the Radiana Site adjacent to the Kozloduy Nuclear Power Plant (KNPP). This paper presents an update on construction planning activities that were originally presented at the 2015 Waste Management Conference. The Site, a rectangular area approximately 1.2 km east-west by 0.4 north-south, is located on a slopping area between the second and sixth loess terraces above the River Danube with elevations ranging from approximately +40 m to elevation +95 m. Construction of the NDF will be divided into three phases separated by approximately 20 years each. The first phase will see the construction of the primary support facilities, referred to as the Auxiliary Buildings and including the Waste Reception and Buffer Storage (WRBS) Building, and the first set of 22 reinforced concrete disposal cells and supporting infrastructure, including a network of subsurface observation galleries, the Infiltration Network Control (ICN) Galleries. Each disposal cell will be 20.15 m long by 17.05 m wide by 9.45 m in height. The disposal cells will be arranged in two parallel rows. Disposal activities will be conducted using overhead cranes installed inside of track mounted mobile roofs. Each row of disposal cells will be serviced by one mobile roof. The mobile roofs will be supported by massive concrete foundations. Construction at the site will present several logistical challenges that will need to be overcome to fully realize the NDF. First in order to begin construction of these facilities nearly 1 million m{sup 3} of soil will require excavation and handling. Consistent with requirements to minimize potential environmental impacts identified in the site Environmental Safety Assessment (EIA) excavated soil will, to the extent possible, remain onsite. Approximately three quarters of the soil can be accommodated within the site boundaries. Another challenge results from requirements imposed by the ground conditions. The sub-grade at the site, which consists primarily of loess, will require considerable improvement. To this end a 5 m thick loess-cement cushion will be constructed across much of the site. Specifically, the cushion will be required beneath the disposal cells and the WRBS Building. The cushion beneath the disposal cells also contains embedded structures, including the ICN Galleries as well as the massive concrete foundation beams required for the two mobile roofs. Construction of these structures will require planned interruptions in the construction of the loess-cement cushion. Specific cement types and strict quality requirements will be required for completion of the loess-cement cushion as well as for the completion of the ICN Galleries. The construction planning will need to account for the large volumes of soil to be excavated as well as ensuring sufficient material supplies in terms of both quality as well as quantity. Large quantities of materials including both dry cement for mixing with the loess, and wet concrete for pouring of the mobile roof foundations are ac-counted for by the plan. However, even after completion of these activities additional challenges are addressed by the plan related to the contemporaneous construction management of the auxiliary buildings and the disposal cells. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Technical Approach for Retrieving Heat-Generating Waste from Repositories in Salt Formations - 16240

During the last decades, the management of SNF and HLW in Germany focused on deep geological disposal inside salt formations. The geological barrier of the rock salt is to safely isolate the waste over a period of one million years. In re-cent years, retrievability has moved into the focus of an ongoing public discus-sion about waste management strategies. The discussion is driven by socio-ethical, economical, safety and technical aspects. As DBE Technology GmbH has expertise in repository safety and technology, the development of technical concepts for retrieving SNF and HLW canisters was launched in an R and D project. This paper summarizes the latest results concerning the implementation of retrievability into existing emplacement concepts for rock salt in Germany and gives an overview of how retrieval could be realized safely and in a technically reliable manner. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

From Banned to Allowed: Pathway to Sub-seabed HLW Repositories - 16279

For many countries the disposal of high-level radioactive waste (HLW) has been delayed due to a number of factors including the Not-In-My-Backyard (NIMBY) syndrome. Sub-seabed disposal has no NIMBY concerns since the disposal facilities utilize sediments underlying approximately 4000 meters of international waters. The technical feasibility of the concept was demonstrated during a 12-year joint effort of over 200 researchers from 10 different countries. Social pressures to keep the oceans off-limits to most disposal activities resulted in termination of the coordinated international effort. However, the treaty banning the concept mandated a 25-year review frequency covering the latest scientific and technical information germane to the activity. An effort is underway to supply information to the signatories of the treaty, in their native languages, so they can make a fully-informed decision -- whether or not to approve an amendment that would allow sub-seabed disposal if determined to be protective of human health and the environment and permitted in accordance with guidelines provided by the International Atomic Energy Agency (IAEA). The information highlights the environmental and safety aspects of the disposal concept within a sensible global stewardship framework. With an amended treaty to allow sub-seabed HLW repositories, the global outlook for nuclear waste disposal would be altered dramatically: the number of potential disposal facilities scattered around the world could be reduced from over sixty land-based to approximately six (three land-based, three sub-seabed). (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Effects of Gamma Radiation on Cementitious Materials in Repository Environment - 16300

Cementitious materials are widely used in the management of radioactive waste and have to perform as required for the period of service life of the installation. In order to assess the long term durability of cement paste in a deep borehole for radioactive wastes, specimens were cast in laboratory and exposed to a gamma radiation field. The effects of the radiation in the specimens were evaluated by X-Ray Diffraction, as changes observed in the mineralogy and microstructure of the material after irradiation doses varying between 0 (without radiation) and 10 MGy. It was observed that the specimens exposed to higher doses of gamma radiation (up to 3 MGy) presented differences between surface and core, when compared with the samples with no radiation or exposed to low doses. These results are important to model the behavior of cementitious materials under the conditions expected in a borehole repository and to provide data for the safety assessment of the installation. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

NWMO Canadian used nuclear fuel repository - 16314

A brief introduction to Canada's Used Fuel Repository Plan, including the status of site selection and the conceptual design. Canada's plan for the long-term care of used nuclear fuel is known as Adaptive Phased Management (APM). It emerged from dialogue with Canadians and experts and best meets the key priorities considered important by citizens. The Federal Government selected APM as Canada's plan in June 2007. The plan is consistent with the long-term management approach adopted by other countries with nuclear power programs, such as Finland, Sweden, Switzerland, the United Kingdom and France. Canada's plan is both a technical method and a management system. The project is designed to be implemented in phases over many decades. New learning and social priorities will be incorporated into Canada's plan for the long-term management of used nuclear fuel, driving refinement and adaptation of the plan throughout its implementation. The major phases for the APM project are described.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Need for an Independent Monitoring of Nuclear Waste Repository: Lessons from WIPP Experience - 18130

The Waste Isolation Pilot Plant (WIPP) is the only operating deep geological repository for the permanent disposal of defense transuranic (TRU) waste in the world. The facility recently resumed waste disposal operations after recovering from a February 2014 accident involving a radiological release from a waste container in the WIPP underground. WIPP had been a DOE success story, operating nearly 15 years with no significant incidents or accidents. Many factors contributed to this success, one of the most important being the overwhelming support exhibited by the local community and the local elected officials. One component of the broad public acceptance by the citizens of Southeast New Mexico has been the concept of independent, third party monitoring of environmental effluents at the site. Independent environmental monitoring ensures a role for the local community in ongoing evaluation of the safety and performance of the site. At WIPP this has been achieved through an independent environmental monitoring program operated by the Carlsbad Environmental Monitoring and Research Center (CEMRC). The CEMRC has been conducting independent environmental monitoring activities on and around the WIPP site since 1991 and makes the results of monitoring activities available and easily accessible to members the general public. The public's free and open access to this data and their direct participation in the CEMRC's whole body counting program provides transparency, which is key to maintaining public trust and confidence. The circumstances following the 2014 radiological release event at WIPP reinforced the value of independent environmental monitoring in order to maintain the high level of transparency necessary for long term local acceptance and support for nuclear facilities. Following what was a minor radiological release event, there were understandably fearful reactions from a number of citizens residing in Carlsbad and the nearby communities of Hobbs, Loving, and Artesia. CEMRC's independent environmental monitoring program and their early public engagement proved invaluable in providing timely and accurate environmental data to local community leaders and members of the general public. The data, and open communication from CEMRC, helped reassure citizens in Carlsbad and the surrounding area that the release was extremely low and the extent was very limited. CEMRC further communicated that the probability of any environmental or health impacts from the release was extremely low. It is unlikely the local community would have placed the same level of trust in similar assurances of safety coming from DOE or other State and Federal regulators. The CEMRC's performance in the days following the release meant the local community had access to independent monitoring data and an independent voice in the dialogue with DOE and state officials that shaped the recovery and eventual re-opening of the WIPP facility. The WIPP radiological release event yielded a plethora of lessons learned that will frame the next phase of operational, oversight, and emergency planning surrounding the facility. In this presentation we will be discussing the value and viability of federally-funded, university-housed independent monitoring programs in maintaining trust of state officials and the local communities. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Potential for Salt Repositories - 18693

Progress toward nuclear waste disposal in the US has been badly corrupted. Since passing and amending the Nuclear Waste Policy Act, the US is further away from geologic disposal than it was in 1987, which was 30 years ago. The waste inventory, liability costs, and elements for dealing with the burgeoning problem continue to increase in complexity - largely because of inaction. The Nuclear Waste Policy Act, as amended, remains the national law in the US. Even if a repository at Yucca Mountain can be licensed, constructed, operated, and closed, the national nuclear waste imperative will not be solved by these actions. Our national challenge includes broad technical problems that are exacerbated by national procrastination, while other countries suffer similarly. This paper discusses several roadblocks that deny progress in our nuclear waste-disposal program, many of which are shared internationally. Recommendations for moving this seemingly overwhelming problem toward solutions are also included. (author)

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

Panel Session 24B: Records, Knowledge, and Memory for Radioactive Waste Repositories: Generational Equity Focus

This panel focused on the latest thoughts, ideas, and methodologies being explored throughout the world on how to communicate with future generations regarding nuclear waste disposal. Scientists determined many years ago that geological disposal in a repository was the preferred solution for nuclear waste disposal given the longevity concerns of the waste(s). Future generations must be informed through records, memory keeping and permanent markers to ensure they are aware of, and knowledgeable of, the dangers associated with nuclear waste isolated from the biosphere. Panelists with presentations: You Want to Drill Where? Human Intrusion Messaging Considerations (Thomas Peake, Jonathan Major); Ethical Reflections on the Basic Reasons for RK and M Measures (Carl-Reinhold Brakenhielm); NEA Activities on Information, Data and Knowledge Management (Rebecca Tadesse); Records, Knowledge and Memory (RK and M) Across Generations: Recent Activities and Progress in Sweden (Claudio Pescatore)

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

Fostering Geothermal Machine Learning Success: Elevating Big Data Accessibility and Automated Data Standardization in the Geothermal Data Repository: Preprint

The Department of Energy's (DOE) Geothermal Data Repository (GDR) has implemented improvements to both its data lakes and its data standards and automated data pipelines. The GDR data lakes have reduced storage and compute-related barriers to using large geothermal datasets, enabling these large datasets to be accessed by anyone with a modern computer and internet access. More recently, the GDR has been working to further reduce barriers through streamlining the data intake process, educating users on the process and requirements, and aiding users in accessing data from the data lakes. These improvements have augmented the quantity of datasets the GDR is able to accept into its data lakes and have enabled users who are new to cloud tools to access these datasets more easily, overall increasing the accessibility of big geothermal data for use in machine learning and other projects. In addition, the GDR now has built-in data standards and pipelines for drilling data, geospatial data, and distributed acoustic sensing (DAS) data. These standardization efforts aim to enhance the real-world applicability of geothermal machine learning outcomes by improving the quality of training data. Specifically, through standardizing high-value datasets, the GDR is reducing project-specific data curation requirements, thus allowing more time for actual research. By automating this process, the burden of standardization is lifted from the user, ultimately increasing the availability of standardized data.

accessibility↗
DOE OSTI2025

Fostering Geothermal Machine Learning Success: Elevating Big Data Accessibility and Automated Data Standardization in the Geothermal Data Repository

The Department of Energy's (DOE's) Geothermal Data Repository (GDR) has implemented improvements to both its data lakes and its data standards and automated data pipelines. The GDR data lakes have reduced storage and compute-related barriers to using large geothermal datasets, enabling these large datasets to be accessed by anyone with a modern computer and internet access. More recently, the GDR has been working to further reduce barriers through streamlining the data intake process, educating users on the process and requirements, and helping users access data from the data lakes. These improvements have augmented the quantity of datasets the GDR is able to accept into its data lakes and have enabled users who are new to cloud tools to access these datasets more easily, overall increasing the accessibility of big geothermal data for use in machine learning and other projects. In addition, the GDR now has built-in data standards and pipelines for drilling data, geospatial data, and distributed acoustic sensing (DAS) data. These standardization efforts aim to enhance the real-world applicability of geothermal machine learning outcomes by improving the quality of training data. Specifically, through standardizing high-value datasets, the GDR is reducing project-specific data curation requirements, thus allowing more time for actual research. By automating this process, the burden of standardization is lifted from the user, ultimately increasing the availability of standardized data. This paper provides an update on recent improvements made to the GDR's data lakes and automated data pipelines, including: (1) streamlining the data lake intake process, (2) better educating users on the process and requirements through a new data lakes page, (3) adding data lake direct access links to GDR data lake submission pages, (4) implementing a DAS data pipeline to convert DAS data uploaded in SEG-Y format to a standardized hierarchical data format v5 (HDF5), (5) extending this pipeline to encompass data in the GDR data lake, (6) adding metadata requirements for geospatial data, (7) making user interface/user experience (UX) enhancements to the data pipelines' documentation pages, and (8) improving the GDR's data standards and pipelines pages to better guide users in ensuring that their data is standardized by the GDR's automated data pipelines. 2024 Geothermal Resources Council. All rights reserved.

accessibility↗
DOE OSTI2023

Long-length Scintillating Fibers for Nuclear Waste Repositories (Conference Record)

This paper describes the fabrication, testing, and characterization of long-length, up to 50 m, scintillating fibers for the purpose of radiation monitoring in inaccessible radiological and nuclear waste repositories. The fabrication aspect was focused on ruggedizing the 1-mm diameter fiber and limiting external light interference for fibers. Testing and characterization were performed in a laboratory setting with radiation sources, a photosensor module and a multi-channel analyzer. Light attenuation was studied as a function of distance by analyzing both the spectrum and count rate. Additionally, the scintillating fibers were coupled to optical communication fibers (100 m) to extend the reach of the system. This paper also includes the optical spectrometry results from the sensitivity and response of the signal attenuation. Lastly, the paper covers the field testing of the scintillating fibers in a relevant environment.

47 - OTHER INSTRUMENTATION↗
DOE OSTI2013

Deep in Data: Empirical Data Based Software Accuracy Testing Using the Building America Field Data Repository

This paper describes progress toward developing a usable, standardized, empirical data-based software accuracy test suite using home energy consumption and building description data. Empirical data collected from around the United States have been translated into a uniform Home Performance Extensible Markup Language format that may enable software developers to create translators to their input schemes for efficient access to the data. This could allow for modeling many homes expediently, and thus implementing software accuracy test cases by applying the translated data.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Impacts of Crystalline Host Rock on Repository Barrier Materials at 250 °C: Hydrothermal Co-Alteration of Wyoming Bentonite and Steel in the Presence of Grimsel Granodiorite

Direct disposal of dual-purpose canisters (DPC) has been proposed to streamline the disposal of spent nuclear fuel. However, there are scenarios where direct disposal of DPCs may result in temperatures in excess of the specified upper temperature limits for some engineered barrier system (EBS) materials, which may cause alteration within EBS materials dependent on local conditions such as host rock composition, chemistry of the saturating groundwaters, and interactions between barrier materials themselves. Here we report the results of hydrothermal experiments reacting EBS materials—bentonite buffer and steel—with an analogue crystalline host rock and groundwater at 250 °C. Experiment series explored the effect of reaction time on the final products and the effects of the mineral and fluid reactants on different steel types. Post-mortem X-ray diffraction, electron microprobe, and scanning electron microscopy analyses showed characteristic alteration of both bentonite and steel, including the formation of secondary zeolite and calcium silicate hydrate minerals within the bentonite matrix and the formation of iron-bearing clays and metal oxides at the steel surfaces. Swelling clays in the bentonite matrix were not quantitatively altered to non-swelling clay species by the hydrothermal conditions. The combined results of the solution chemistry over time and post-mortem mineralogy suggest that EBS alteration is more sensitive to initial groundwater chemistry than the presence of host rock, where limited potassium concentration in the solution prohibits conversion of the smectite minerals in the bentonite matrix to non-swelling clay species.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

The Zooplankton International Geospatial dataset: A global repository of spatiotemporal freshwater zooplankton community composition data from lakes and reservoirs to support ecological research

Zooplankton transfer substantial energy in aquatic food webs and are used as indicators of environmental change. Syntheses of zooplankton community dynamics globally require datasets that span a wide range of environmental gradients; however, these datasets are limited due to methodological differences across programs, taxonomic inconsistencies, and a lack of standardized metadata. To reconcile these challenges, we created the Zooplankton International Geospatial (ZIG) dataset, which includes original zooplankton, water physical and chemical variables, and lake morphometric data from 311 inland lakes and reservoirs. ZIG includes waterbodies ranging in size from 0.005 to 82,100 km2 and spanning broad latitudinal (−47.26 to 64.90) and longitudinal ranges (−165.04 to 176.53). Temporal coverage for individual waterbodies ranges between 1 and 60 yr with sampling frequency ranging from annually to weekly. With its extensive coverage and content, we consider ZIG to be a cornerstone for future investigations of global scale lake biodiversity change.

Figary, Stephanie [Cornell University, Ithaca, NY]↗