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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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DOE OSTI2011

NA-42 TI Shared Software Component Library FY2011 Final Report

The NA-42 TI program initiated an effort in FY2010 to standardize its software development efforts with the long term goal of migrating toward a software management approach that will allow for the sharing and reuse of code developed within the TI program, improve integration, ensure a level of software documentation, and reduce development costs. The Pacific Northwest National Laboratory (PNNL) has been tasked with two activities that support this mission. PNNL has been tasked with the identification, selection, and implementation of a Shared Software Component Library. The intent of the library is to provide a common repository that is accessible by all authorized NA-42 software development teams. The repository facilitates software reuse through a searchable and easy to use web based interface. As software is submitted to the repository, the component registration process captures meta-data and provides version control for compiled libraries, documentation, and source code. This meta-data is then available for retrieval and review as part of library search results. In FY2010, PNNL and staff from the Remote Sensing Laboratory (RSL) teamed up to develop a software application with the goal of replacing the aging Aerial Measuring System (AMS). The application under development includes an Advanced Visualization and Integration of Data (AVID) framework and associated AMS modules. Throughout development, PNNL and RSL have utilized a common AMS code repository for collaborative code development. The AMS repository is hosted by PNNL, is restricted to the project development team, is accessed via two different geographic locations and continues to be used. The knowledge gained from the collaboration and hosting of this repository in conjunction with PNNL software development and systems engineering capabilities were used in the selection of a package to be used in the implementation of the software component library on behalf of NA-42 TI. The second task managed by PNNL is the development and continued maintenance of the NA-42 TI Software Development Questionnaire. This questionnaire is intended to help software development teams working under NA-42 TI in documenting their development activities. When sufficiently completed, the questionnaire illustrates that the software development activities recorded incorporate significant aspects of the software engineering lifecycle. The questionnaire template is updated as comments are received from NA-42 and/or its development teams and revised versions distributed to those using the questionnaire. PNNL also maintains a list of questionnaire recipients. The blank questionnaire template, the AVID and AMS software being developed, and the completed AVID AMS specific questionnaire are being used as the initial content to be established in the TI Component Library. This report summarizes the approach taken to identify requirements, search for and evaluate technologies, and the approach taken for installation of the software needed to host the component library. Additionally, it defines the process by which users request access for the contribution and retrieval of library content.

99 GENERAL AND MISCELLANEOUS↗
NASA NTRS1989

AdaNET phase 0 support for the AdaNET Dynamic Software Inventory (DSI) management system prototype. Catalog of available reusable software components

The Ada Software Repository is a public-domain collection of Ada software and information. The Ada Software Repository is one of several repositories located on the SIMTEL20 Defense Data Network host computer at White Sands Missile Range, and available to any host computer on the network since 26 November 1984. This repository provides a free source for Ada programs and information. The Ada Software Repository is divided into several subdirectories. These directories are organized by topic, and their names and a brief overview of their topics are contained. The Ada Software Repository on SIMTEL20 serves two basic roles: to promote the exchange and use (reusability) of Ada programs and tools (including components) and to promote Ada education.

Hanley, Lionel↗
NASA NTRS2010

System and method for responding to ground and flight system malfunctions

A system for on-board anomaly resolution for a vehicle has a data repository. The data repository stores data related to different systems, subsystems, and components of the vehicle. The data stored is encoded in a tree-based structure. A query engine is coupled to the data repository. The query engine provides a user and automated interface and provides contextual query to the data repository. An inference engine is coupled to the query engine. The inference engine compares current anomaly data to contextual data stored in the data repository using inference rules. The inference engine generates a potential solution to the current anomaly by referencing the data stored in the data repository.

Fussell, Ronald M.↗
NASA NTRS2019

Data Preservation: Final Step in the Life Cycle of a Mission

Many NASA Earth Observing System (EOS) have either already reached the end of their active life or are nearing it. Preservmissionsation of data products is a fairly well defined task for the NASA EOS Data Centers or DAACs.The Goddard Earth Sciences Data and Information Services Center (GES-DISC) has implemented a repository system, which is capable of long-term archive of documentation artifacts and other associated digital content. The existing GES-DISC Repository System is based on Fedora Commons, an open-source repository management software, for cost savings and flexibility.The first mission to utilize the GES-DISC Repository System was the High Resolution Dynamics Limb Sounder (HIRDLS) on the Aura spacecraft. Since then, the GES DISC has gathered documentation from the UARS and TOMS into the Repository. The Microwave Limb Sounder (MLS) team has begun delivering some early pre-launch documents to the GES-DISC Repository System as well. Other missions in planning or progress include AIRS, OMI, SORCE, SNPP Sounder, and TRMM.

Johnson, J.↗
DOE OSTI2017

Preliminary Concept of Operations for the Spent Fuel Management System--WM2017

The Nuclear Fuels Storage and Transportation Planning Project (NFST) within the U.S. Department of Energy s Office of Nuclear Energy is tasked with identifying, planning, and conducting activities to lay the groundwork for developing interim storage and transportation capabilities in support of an integrated waste management system. The system will provide interim storage for commercial spent nuclear fuel (SNF) from reactor sites and deliver it to a repository. The system will also include multiple subsystems, potentially including; one or more interim storage facilities (ISF); one or more repositories; facilities to package and/or repackage SNF; and transportation systems. The project team is analyzing options for an integrated waste management system. To support analysis, the project team has developed a Concept of Operations document that describes both the potential integrated system and inter-dependencies between system components. The goal of this work is to aid systems analysts in the development of consistent models across the project, which involves multiple investigators. The Concept of Operations document will be updated periodically as new developments emerge. At a high level, SNF is expected to travel from reactors to a repository. SNF is first unloaded from reactors and placed in spent fuel pools for wet storage at utility sites. After the SNF has cooled enough to satisfy loading limits, it is placed in a container at reactor sites for storage and/or transportation. After transportation requirements are met, the SNF is transported to an ISF to store the SNF until a repository is developed or directly to a repository if available. While the high level operation of the system is straightforward, analysts must evaluate numerous alternative options. Alternative options include the number of ISFs (if any), ISF design, the stage at which SNF repackaging occurs (if any), repackaging technology, the types of containers used, repository design, component sizing, and timing of events. These alternative options arise due to technological, economic, or policy considerations. As new developments regularly emerge, the operational concepts will be periodically updated. This paper gives an overview of the different potential alternatives identified in the Concept of Operations document at a conceptual level.

Cumberland, Riley M↗
DOE OSTI2012

Opportunities for the Multi Recycling of Used MOX Fuel in the US - 12122

Over the last 50 years the US has accumulated an inventory of used nuclear fuel (UNF) in the region of 64,000 metric tons in 2010, and adds an additional 2,200 metric tons each year from the current fleet of 104 Light Water Reactors. This paper considers a fuel cycle option that would be available for a future pilot U.S. recycling plant that could take advantage of the unique opportunities offered by the age and size of the large U.S. UNF inventory. For the purpose of this scenario, recycling of UNF must use the available reactor infrastructure, currently LWR's, and the main product of recycling is considered to be plutonium (Pu), recycled into MOX fuel for use in these reactors. Use of MOX fuels must provide the service (burn-up) expected by the reactor operator, with the required level of safety. To do so, the fissile material concentration (Pu-239, Pu-241) in the MOX must be high enough to maintain criticality, while, in current recycle facilities, the Pu-238 content has to be kept low enough to prevent excessive heat load, neutron emission, and neutron capture during recycle operations. In most countries, used MOX fuel (MOX UNF) is typically stored after one irradiation in an LWR, pending the development of the GEN IV reactors, since it is considered difficult to directly reuse the recycled MOX fuel in LWRs due to the degraded Pu fissile isotopic composition. In the US, it is possible to blend MOX UNF with LEUOx UNF from the large inventory, using the oldest UNF first. Blending at the ratio of about one MOX UNF assembly with 15 LEUOx UNF assemblies, would achieve a fissile plutonium concentration sufficient for reirradiation in new MOX fuel. The Pu-238 yield in the new fuel will be sufficiently low to meet current fuel fabrication standards. Therefore, it should be possible in the context of the US, for discharged MOX fuel to be recycled back into LWR's, using only technologies already industrially deployed worldwide. Building on that possibility, two scenarios are assessed where current US inventory is treated; Pu recycled in LWR MOX fuels, and used MOX fuels themselves are treated in a continuous partitioning-transmutation mode (case 2a) or until the whole current UNF inventory (64,000 MT in 2010) has been treated followed by disposal of the MOX UNF to a geologic repository (case 2b). In the recycling scenario, two cases (2a and 2b) are considered. Benefits achieved are compared with the once through scenario (case 1) where UNF in the current US inventory are disposed directly to a geologic repository. For each scenario, the heat load and radioactivity of the high activity wastes disposed to a geologic repository are calculated and the savings in natural resources quantified, and compared with the once-through fuel cycle. Assuming an initial pilot recycling facility with a capacity of 800 metric tons a year of heavy metal begins operation in 2030, ∼8 metric tons per year of Pu is recovered from the LEUOx UNF inventory, and is used to produce fresh MOX fuels. At a later time, additional treatment and recycling capacities are assumed to begin operation, to accommodate blending and recycling of used MOX Pu, up to 2,400 MT/yr treatment capacity to enable processing UNF slightly faster than the rate of generation. Results of this scenario analysis study show the flexibility of the recycling scenarios so that Pu is managed in a way that avoids accumulating used MOX fuels. If at some future date, the decision is made to dispose of the MOX UNF to a geologic repository (case 2b), the scenario is neutral to final repository heat load in comparison to the direct disposal of all UNF (case 1), while diminishing use of natural uranium, enrichment, UNF accumulation, and the volume of HLW. Further recycling of Pu at the end of the scenario (case 2a) would exhibit further benefits. As expected, Pu-241 and Am-241 are the source of long term HLW heat load and Am-241 and Np-237 are the source of long term radiotoxicity. When advanced technology is available, introduction of minor actinide recycling, in addition to Pu recycling, by the end of this scenario, or sooner, would have a major impact on final repository heat load and long term radiotoxicity of the HLW. This scenario is also compatible with a gradual introduction of a small number of FR's for Pu management. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2012

Principles of Product Quality Control of German Radioactive Waste Forms from the Reprocessing of Spent Fuel: Vitrification, Compaction and Numerical Simulation - 12529

The German product quality control is inter alia responsible for control of two radioactive waste forms of heat generating waste: a) homogeneous vitrified HLW and b) heterogeneous compacted hulls, end-pieces and technological metallic waste. In either case, significantly different metrology is employed at the site of the conditioning plant for the obligatory nuclide inventory declaration. To facilitate an independent evaluation and checking of the accompanying documentation numerical simulations are carried out. The physical and chemical properties of radioactive waste residues are used to assess the data consistency and uncertainty margins, as well as to predict the long-term behavior of the radioactive waste. This is relevant for repository acceptance and safety considerations. Our new numerical approach follows a bottom-up simulation starting from the burn-up behavior of the fuel elements in the reactor core. The output of these burn-up calculations is then coupled with a program that simulates the material separation in the subsequent dissolution and extraction processes normalized to the mass balance. Follow-up simulations of the separated reprocessing lines of a) the vitrification of highly-active liquid and b) the compaction of residual intermediate-active metallic hulls remaining after fuel pellets dissolution, end-pieces and technological waste, allows calculating expectation values for the various repository relevant properties of either waste stream. The principles of the German product quality control of radioactive waste residues from the spent fuel reprocessing have been introduced and explained. Namely, heat generating homogeneous vitrified HLW and heterogeneous compacted metallic MLW have been discussed. The advantages of a complementary numerical property simulation have been made clear and examples of benefits are presented. We have compiled a new program suite to calculate the physical and radio-chemical properties of common nuclear waste residues. The immediate benefit is the independent assessment of radio-active inventory declarations and much facilitated product quality control of waste residues that need to be returned to Germany and submitted to a German HLW-repository requirements. Wherever possible, internationally accepted standard programs are used and embedded. The innovative coupling of burn-up calculations (SCALE) with neutron and gamma transport codes (MCPN-X) allows an application in the world of virtual waste properties. If-then-else scenarios of hypothetical waste material compositions and distributions provide valuable information of long term nuclide property propagation under repository conditions over a very long time span. Benchmarking the program with real residue data demonstrates the power and remarkable accuracy of this numerical approach, boosting the reliability of the confidence aforementioned numerous applications, namely the proof tool set for on-the-spot production quality checking and data evaluation and independent verification. Moreover, using the numerical bottom-up approach helps to avoid the accumulation of fake activities that may gradually build up in a repository from the so-called conservative or penalizing nuclide inventory declarations. The radioactive waste properties and the hydrolytic and chemical stability can be predicted. The interaction with invasive chemicals can be assessed and propagation scenarios can be developed from reliable and sound data and HLW properties. Hence, the appropriate design of a future HLW repository can be based upon predictable and quality assured waste characteristics. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Preliminary Concept of Operations for the Spent Fuel Management System+ - 17134

The Nuclear Fuels Storage and Transportation Planning Project (NFST) within the US Department of Energy's Office of Nuclear Energy is tasked with identifying, planning, and conducting activities for developing interim storage and transportation capabilities in support of an integrated waste management system (IWMS). The IWMS is expected to transport Spent Nuclear Fuel (SNF) from a reactor and deliver it to a repository in a suitable container, with the possibility of interim storage. The system will be composed of multiple subsystems including possible interim storage facilities (ISFs), one or more repositories, facilities to package and/or repackage SNF, and transportation. The project team is analyzing options for an IWMS to identify viable options. To support analysis, the project team has developed a concept of operations framework for SNF related components of the potential integrated system and the interdependencies between those components. A goal of this work is to aid system analysts in developing consistent models across the project. The concept of operations framework will be updated periodically as new developments emerge. At a high level, SNF is expected to be transported from reactor sites to a repository. Initially, SNF is unloaded from reactors and placed in spent fuel pools (SFPs) for wet storage at utility sites. To maintain space in SFPs, SNF is placed in containers at reactor sites for storage and/or transportation only after the SNF has cooled enough to satisfy loading limits. Once transportation requirements are met, the SNF may be transported to an ISF, where it is stored until a repository is developed, or it is transported directly to a repository if one is available.While the high level operation of the system is straightforward, analysts must evaluate numerous alternatives, such as the number of ISFs (if any), ISF design, the stage at which SNF repackaging occurs (if needed), repackaging technology, types of containers used, repository design, component sizing, and timing of events. These alternatives arise due to technological, economic, or policy considerations. This paper provides an overview of the potential alternatives identified in the concept of operations framework at a conceptual level. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

There Are Safe Limits for Radioactivity - Does WIPP Need to Filter its Exhaust Air? - 17165

Pilot Plant (WIPP) underground repository resulted in the release of americium and plutonium (mostly {sup 241}Am) into the environment and contaminated portions of the repository, primarily along the ventilation path from the location of the incident. The WIPP uses a ventilation system to ensure that underground air is circulated through the repository and to ensure that air quality conditions are safe for the workers. Since the air in the repository exits to the surface through an exhaust shaft, this shaft is the sole potential pathway for airborne radioactivity release from the repository. During normal operations before the 2014 incident, exhaust air was released to the environment unfiltered, with an automatic switch to filtration when airborne radioactivity was detected immediately down-stream from the active waste disposal operation. However, since the radiation release event, the WIPP ventilation system has been, and will likely remain in what is called 'filtration mode,' (i.e., exhaust air is routed through a HEPA filter system). Redirection of the ventilation system through the HEPA (High Efficiency Particulate Air) filter system was necessary at the peak of the radiation release event to protect aboveground workers at the site and the public in the surrounding areas; however, it has hampered recovery efforts and has exacerbated the inherent safety issues of working underground. As a component of the Carlsbad Environmental Monitoring and Research Center's (CEMRC) WIPP environmental monitoring program, airborne radioactivity samples are collected daily in the exhaust shaft ventilation air as it reaches the surface, and before entering the HEPA filters. Since June 2014, airborne radiation levels entering the HEPA filters have averaged about 1% of a derived air concentration (DAC) for {sup 241}Am. An airborne radioactivity level of one DAC is equivalent to a potential worker internal dose exposure of 50 mSv per work year, if a worker were continuously exposed for a full work year (2000 hours). During Project Reach and throughout decontamination campaigns conducted in Panel 7 for several months in 2015, these unfiltered levels rose to 3-5% of a DAC, with a one week spike reaching almost one DAC in June 2015, during decontamination of the most heavily contaminated exhaust drift in Panel 7. Since that period, the unfiltered levels have never exceeded 2% of a DAC. Going forward, the question is, should WIPP resume unfiltered discharge of its underground ventilation air? Evaluation of more than two years of underground ventilation sampling data indicates that residual radioactivity levels in the underground no longer warrant HEPA filtration in order to meet either worker or environmental protection criteria. In terms of radiological risk at or in the vicinity of the WIPP site, the increased risk from resuming unfiltered ventilation is exceedingly small and would not result in a hypothetical dose to a member of the public in excess of the 100 micro Sv per year limit for periodic confirmatory sampling as required for operating repositories by the Environmental Protection Agency (40 CFR 191). In addition, the requirement for respiratory protection for workers underground exposed to 1-2% of a DAC is questionable, given the added industrial safety risk of heavy equipment operation while wearing respirators. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Encapsulation of ILW metals by melting technology - 15360

This paper outlines how encapsulation using melting technology can be performed and describe the positive effects in a handling and repository perspective. Based on a feasibility study of a conditioning method for reactor core components and other ILW metals with a high content of long-lived radionuclides, the paper gives an overview of the concept and how the method can be facilitated. The paper covers identification and analysis of alternative techniques that supports the aim from a repository perspective, which is to strengthen the defense in depth for long-lived waste to be disposed. Embedding of radioactive metallic ILW components can isolate the activated component from corrosion and leakage of radionuclides into the repository barrier systems. By implementing a system that delays the mobility of nuclides the leakage to the biosphere can be delayed and by then decreased significantly. Conditioning by embedding has potential to strengthen a repository concept significantly. It may in certain cases also reduce the requirements on the repository barriers. In addition to the above, embedding also serves as an efficient radiation protection, which simplifies post treatment handling of the waste. The concept can be applied on a wide spectrum of metallic components. Positive effects in a handling and repository perspective can be achieved if low level metal not subject to free release is used as embedding material, since conditioning of metallic ILW waste can be carried out at significant lower dose rates and without increasing the total amount to be disposed. The paper discuss why there are embedding alternatives for ILW metals that are considered to be both technically feasible and reasonable in cost both with regards to investment and operational cost. A cost-benefit analysis as well as a risk analysis is discussed in order to support the feasibility assessment of a facility for encapsulation of ILW metals by melting technology. (authors)

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

Salt Rock - the 60-Year-Old Prodigy Host Rock for Consent-Based Disposal of Long-Lived Radioactive Waste - 16010

The USA's HLW-disposal program has been on hold since 2010 pending enabling legislation for its only candidate HLW-repository since 1987 at the Yucca Mountain site in Nevada and/or other, 'consent-based', HLW-disposition solutions. Related projections in 2008 and 2012 suggested they might open 9-12 years and 35 years after being adequately enabled, respectively. In 2014, domestic HLW arisings exceeded the capacity of the candidate repository by >4,000 metric tons (MT) and they were projected to grow by 2,000-2,300 MT/year. One or more new HLW repositories are thus highly-likely in the future. In the meantime, the DOE should make every effort to promptly take title to civilian-generated HLW by other means. Historical evidence in the USA and abroad during the past 30+ years shows that all HLW-repository siting and development schedules and costs are governed by the inherent, intricate, relationships and related domino effects of the: 1. Maturity/robustness of the disposal concept; 2. Related levels of relevant domestic repository-sciences/engineering expertise, data, institutional knowledge, and applicable regulations; 3. Abundance and 'ease' of physical access to potentially-suitable host-rock sites; 4. 'Trust' in the implementing and regulating organizations; 5. Timely resolution of inevitable contentions and lawsuits; 6. Facility-host-acceptance level; 7. Timely and adequate enabling legislation, and therefore, ultimately, by 8. Prevailing Political Will. Based upon their respective status at the end of 2015, salt rock still offers the most, but not the only, promising path forward for new, mined, HLW repositories in the USA, and ∼5-km-deep boreholes offer the most-promising disposal-solution for small HLW containers/packages/pellets. (authors)

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

A Conceptual World Information Library (WIL) and Land Use Information System (LUIS) - 16181

The Organization for Economic Co-operation and Development Nuclear Energy Agency initiative on the Preservation of Records, Knowledge and Memory is addressing the topic of communicating with future generations on the location, specific contents, and potential risks associated with deep geologic nuclear waste repositories. At the Waste Isolation Pilot Plant (WIPP) in the United States, the U.S. Department of Energy (DOE) has committed, prior to the facility closure, to develop a Passive Institutional Controls (PICs) program designed to last as long as practicable. A portion of this PICs program includes development of records packages, selection of data storage materials and methods, and a determination of records retention/storage locations. The approved plan for record retention at WIPP includes the storage of information including hard copies of data, figures and maps in multiple libraries and archive record centers. With this in mind, it is easy to envision reams of various paper documents in a robust physical archive record center similar to one of the museums in Washington D.C., or DOE's Legacy Management facility in Morgantown, West Virginia. While some portion of records for nuclear waste burial sites should be maintained in this fashion for near-term retrieval purposes, it is widely accepted that this is not an efficient way to communicate with future generations even 1,000 years from now. Transmitting large detailed volumes of information to the future should be captured in an electronic format; maintained on computers, translated by computers, and perhaps updated by artificial intelligence as machine and human languages change over the centuries. In addition to a physical records development and storage process for transmittal to future generations, a web-based electronic database system should be developed. A World Electronic Library (WEL) database could be funded from various nations and perhaps sanctioned by the United Nations and/or the IAEA. This WEL could contain information regarding several different subjects with the intent of being a one-stop-information-shop for future generations. This database would require updates and maintenance for as long as there is a recipient. One subset of the WEL would be a spatial database containing all the information available to any set of GPS coordinates, anywhere within the world. This Land Use Information System (LUIS) database would contain information on past and present land use, natural resources, known geology, hydrology and atmospheric conditions, potential warnings, and other pertinent information. The LUIS database is where specific electronic information, a subset of all the records data gathered for a nuclear waste repository, could reside. For not only would LUIS provide the information on a nuclear waste repository when specific GPS coordinates were entered; but a search from the LUIS on 'Nuclear Waste Repositories' could bring up information, including data on location of repositories, radionuclides, operations, D and D, maps, and regulations, plus many other details for locations throughout the world. This tool could be used by future generations for a number of land use or resource exploration decisions. So what can we do now? We can agree to the types of information that should be captured into an electronic database for nuclear waste repositories. We can agree to the levels of detail, the file names and the formats, for ease of combining information sets in the future. Perhaps we can agree to a central electronic data storage site, or sites, where this information will reside for import into a centralized electronic record system, if one is ever developed. (authors)

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

Realization of the National Disposal Facility for Radioactive Waste in Bulgaria - 16611

Radioactive waste is generated in the Republic of Bulgaria from the operation and decommissioning of the country's nuclear power plants and from other sources in research, medical applications, and the industry. The need for building a National Disposal Facility (NDF) is recognized by the Bulgarian government and described and justified in its Environment Impact Assessment Decision. The Bulgarian State Enterprise for Radioactive Waste Management (SERAW) is endeavoring to build a near-surface repository for short-lived low- and intermediate-level radioactive waste (SL-LILW) to discharge its statutory responsibilities in waste management is. The European Union (EU) finances the establishment of the NDF through the Kozloduy International Decommissioning Support Fund (KIDSF). After an international tendering procedure, SERAW placed a contract for the development of the design of the NDF to the Consortium of Westinghouse Electric Spain S.A.R and DBE Technology GmbH of Germany, with ENRESA, the Spanish National Waste Management Agency providing technical review and support. Two Bulgarian companies participate also in the project as subcontractors - EQE Bulgaria and to a lesser extent KK-Project. The repository project official name is 'Technical Design and ISAR Preparation for the National Disposal Facility at Bulgaria', usually abbreviated as 'R-Project 5'. After obtaining SERAW's approval for the preferred repository conceptual design variant, the R Project 5 focused on developing the Technical Design on the one hand, and on preparing the Intermediate Safety Analysis Report (ISAR) to demonstrate the safety and suitability of the proposed NDF design on the other. These documents were handed over to the Bulgarian Nuclear Regulatory Authority (BNRA) as well as to the different authorities involved in the comprehensive licensing process required for nuclear facilities in the country. The corresponding permits have mostly been received or are expected for early 2016. In the last quarter of 2015 the procurement procedure for repository construction as turn-key project was started with the pre-qualification of possible constructors for the Phase I repository realization on a lump sum contract basis. Repository construction is now expected to start in 2016, with the start of waste disposal now scheduled for around 2020. With the realization of the Bulgarian National Disposal Facility an important milestone for waste disposal in the European Union is about to be achieved. This paper is a sequel of previously presented papers on the NDF construction, now including details of the complex licensing process that this disposal facility underwent, now in its final stages. (authors)

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

Reduction of the Waste Occupied Area by Nuclide Separation and Horizontal Emplacement of the Waste Packages - 20422

Two of the key objectives for realizing the advanced nuclear fuel cycle are to reduce the volume of high-level radioactive waste and to reduce the foot-print of the geological repository. To achieve these objectives, research and development on nuclide separation technologies is a prerequisite. In this context, it is necessary to consider the vitrification conditions and the design of the geological repository where separation technologies would be implemented to achieve effective reductions in the volume of vitrified waste and the foot-print of the geological repository. In this study, the effects of the vitrification conditions on the number of vitrified waste units and the disposal area were evaluated, based on the assumption that separation of Cs and Sr from the spent nuclear fuel had been performed. In addition, with reference to the design of the geological repository, the impact on the foot-print of the repository for different emplacement methods of the waste packages was examined. As a result, it was clarified that the waste-occupied area could be reduced by horizontal emplacement of the vitrified waste with low heat generation. In addition, it was demonstrated that a low waste-loaded vitrified waste contributed to a reduction in the foot-print of the geological repository in the case of horizontal emplacement, although the number of vitrified waste units increased. (authors)

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

Technical Evaluation of the Department of Energy Research and Development Activities in Underground Research Laboratories - 20287

Congress created the U.S. Nuclear Waste Technical Review Board (NWTRB) in the 1987 Nuclear Waste Policy Amendments Act (Public Law 100-203) to evaluate the technical and scientific validity of activities undertaken by the Secretary of Energy to implement the Nuclear Waste Policy Act. Since 2012, DOE has collaborated in research conducted in several underground research laboratories (URLs) located in Europe and Asia. According to DOE, these international collaborations have been beneficial to its spent nuclear fuel (SNF) and high-level waste radioactive (HLW) disposal research program, particularly after the termination of the Yucca Mountain repository program when DOE began generic research on alternative host rocks (crystalline, clay, and salt) and repository environments very different from those at Yucca Mountain. In accordance with its mandate, the NWTRB is reviewing the DOE research and development (R and D) activities related to URLs. The NWTRB's review is documented in a report to Congress and the Secretary of Energy that will be released in January 2020, and this paper summarizes the NWTRB review and findings. The NWTRB held a fact-finding meeting with DOE and subsequently held a workshop on international URL collaborations in April of 2019. Based on the presentations and discussions at the workshop and at the fact-finding meeting, as well as information from reports published by DOE and others, there are four principal findings related to DoE's URL-related R and D activities. First, DOE participation in URL-related international research greatly benefits the U.S. geologic disposal R and D program by furthering its understanding of generic and site-specific disposal issues relevant to alternative repository host rocks and environments. DOE-funded R and D activities also are benefiting the URL-related research of other countries, especially in the area of complex analytical and numerical model/software development. Second, the more developed repository programs in other countries have focused on creating and strengthening their safety cases and making them transparent to the public. Repository programs in other countries use URLs to explain the technical bases underlying their safety cases, periodically reassess knowledge gaps and define new activities to strengthen the technical bases, and demonstrate the technology that will allow implementation of the proposed safety concept. Third, countries with more developed geologic disposal programs have found domestic URLs essential to their repository programs. DOE needs domestic URLs to advance geologic disposal efforts over the next decades and further its ability to train the next generation of scientists, engineers, and skilled technical workers. Fourth, DoE's international URL collaborations have advanced its generic disposal R and D program, including development of modeling capabilities recognized internationally as state-of-the-art, but further work on its coupled thermal-hydrological-mechanical-chemical models and URL- and laboratory-based research can strengthen its program. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Should WIPP Resume Unfiltered Discharge of Underground Ventilation?

On February 14, 2014 an incident in Panel 7, Room 7 of the Waste Isolation Pilot Plant (WIPP) underground repository resulted in the release of americium and plutonium (mostly {sup 241}Am) into the environment and contaminated portions of the repository primarily along the ventilation path from the location of the incident. The WIPP uses a ventilation system to ensure that underground air is circulated throughout the repository and to ensure that conditions are safe for the workers. Since the air in the repository exits to the surface through an exhaust shaft, this shaft is the sole potential pathway for airborne radioactivity release from the repository. During normal operations, exhaust air is released to the environment unfiltered. However, since the radiation release event, the WIPP ventilation system has been, and will likely remain in what is called 'filtration mode', (i.e., exhaust air is routed through a HEPA filter system). Redirection of the ventilation system through the HEPA (High Efficiency Particulate Air) filter system was necessary at the peak of the radiation release event to protect aboveground workers at the site and the public in the surrounding areas. However, evaluation of more than two years of underground ventilation sampling data indicates that residual radioactivity levels in the underground no longer warrant HEPA filtration in order to meet either worker or environmental protection criteria. WIPP should consider resumption of the unfiltered discharge of underground ventilation to the environment. Recent sampling data indicate that there have been no detectable releases that would have resulted in a hypothetical dose to a worker or a member of the public in excess of the 0.1 mSv (10 mrem) per year limit for periodic confirmatory sampling as required for operating repositories by the Environmental Protection Agency (40 CFR 191)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Temperature-dependent microbial reactions by indigenous microbes in bentonite under Fe(III)- and sulfate-reducing conditions

Bentonite is a promising buffer material for constructing spent nuclear fuel (SNF) repositories. However, indigenous microbes in bentonite can be introduced to the repository and subsequent sealing of the repository develops anoxic conditions over time which may stimulate fermentation and anaerobic respiration, possibly affecting bentonite structure and SNF repository stability. Moreover, the microbial activity in the bentonite can be impacted by the heat generated from radionuclides decay. Therefore, to investigate the temperature effect on microbial activities in bentonite, we created microcosms with WRK bentonil (a commercial bentonite) using lactate as the electron donor, and sulfate and/or ferrihydrite (Fe(III)) as electron acceptors with incubation at 18 °C and 50 °C. Indigenous WRK microbes reduced sulfate and Fe(III) at both temperatures but with different rates and extents. Lactate was metabolized to acetate at both temperatures, but only to propionate at 18 °C during early-stage microbial fermentation. More Fe(III)-reduction at 18 °C but more sulfate-reduction at 50 °C was observed. Thermophilic and/or metabolically flexible microbes were involved in both fermentation and Fe(III)/ sulfate reduction. In conclusion, our findings illustrate the necessity of considering the influence of temperature on microbial activities when employing bentonite as an engineered buffer material in construction of SNF repository barriers.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Dataset for "Evaluating Deep Learning Approaches for Predictions in Unmonitored Basins with Continental-scale Stream Temperature Models" Willard et al. (2024)

This data release provides all data and code used in the paper " "Evaluating Deep Learning Approaches for Predictions in Unmonitored Basins with Continental-scale Stream Temperature Models" Willard et al. (2024)" to model stream temperature, evaluate, and assess results. The associated manuscript explores current open questions in prediction in ungauged and unmonitored basins concerning top-down versus bottom-up approaches, tradeoffs between data available and input requirements, and the appropriate representation of catchment attributes as inputs to deep learning models. Modeling was done primarily with long short-term memory (LSTM) models, and stream site coverage spans 1362 locations across the conterminous United States. The data is organized into these items items:Code repository and data for the paper " "Evaluating Deep Learning Approaches for Predictions in Unmonitored Basins with Continental-scale Stream Temperature Models" Willard et al. (2024)".Code: stream_temp_ml_regionalization.zip contains the code repositoryData to run the code: - data_dir.zip -- contains all files that should be moved to the "DATA_DIR" variable defined in the "set_env_vars.sh" script in the code repository- metadata_dir.zip -- contains all files that should be moved to the "METADATA_DIR" variable defined in the "set_env_vars.sh" script in the code repository- error_analysis_attribute_and_groundwater_dir.zip - workflows for the extended error analysis by stream attribute and groundwater influenceData produced by the code and used in the paper:- outputs_dir.zip - contains model output and results (outputs_dir/results), model weights (outputs_dir/models), and all other outputs used for the paper including feature importances.To cite this code, please use the following BibTeX or MLA entries:bibtex:@misc{willard2024streamdata, author = {Jared Willard and Fabio Ciulla and Helen Weierbach and Vipin Kumar and Charuleka Varadharajan}, title = {Dataset for "Evaluating Deep Learning Approaches for Predictions in Unmonitored Basins with Continental-scale Stream Temperature Models"}, year = {2024}, doi = {10.15485/2448016}, publisher = {ESS-DIVE Repository}, url = {https://doi.org/10.15485/2448016}}MLA: Willard, Jared, et al. Dataset for "Evaluating Deep Learning Approaches for Predictions in Unmonitored Basins with Continental-scale Stream Temperature Models". 2024. ESS-DIVE Repository, doi:10.15485/2448016.

54 ENVIRONMENTAL SCIENCES↗