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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 973 records · Page 54
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

The Initial Development of a Computerized Operator Support System

A computerized operator support system (COSS) is a collection of resilient software technologies to assist operators in monitoring overall nuclear power plant performance and making timely, informed decisions on appropriate control actions for the projected plant condition. The COSS provides rapid assessments, computations, and recommendations to reduce workload and augment operator judgment and decision-making during fast- moving, complex events. A prototype COSS for a chemical volume control system at a nuclear power plant has been developed in order to demonstrate the concept and provide a test bed for further research. The development process identified four underlying elements necessary for the prototype, which consist of a digital alarm system, computer-based procedures, piping and instrumentation diagram system representations, and a recommender module for mitigation actions. An operational prototype resides at the Idaho National Laboratory (INL) using the U.S. Department of Energy’s (DOE) Light Water Reactor Sustainability (LWRS) Human Systems Simulation Laboratory (HSSL). Several human-machine interface (HMI) considerations are identified and incorporated in the prototype during this initial round of development.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2015

A COMPUTERIZED OPERATOR SUPPORT SYSTEM PROTOTYPE

A computerized operator support system (COSS) is proposed for use in nuclear power plants to assist control room operators in addressing time-critical plant upsets. A COSS is a collection of technologies to assist operators in monitoring overall plant performance and making timely, informed decisions on appropriate control actions for the projected plant condition. A prototype COSS was developed in order to demonstrate the concept and provide a test bed for further research. The prototype is based on four underlying elements consisting of a digital alarm system, computer-based procedures, piping and instrumentation diagram system representations, and a recommender module for mitigation actions. The initial version of the prototype is now operational at the Idaho National Laboratory using the Human System Simulation Laboratory.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2015

Significance of Dynamic and Transient Analysis in the Design and Operation of Hybrid Energy Systems

Energy systems were historically designed and operated with a specific energy conversion objective, while managing loads and resources. In the recent years, the increased utilization of non-dispatchable renewable sources such as wind and solar has played a role in power quality and the reliability of power systems. In order to mitigate the risk associated with the non-dispatchable resources an integrated approach, such as Hybrid Energy Systems (HES), has to be taken, integrating the loads and resource management between the traditional thermal power plants and the non-dispatchable resources. As our electric energy becomes more diverse in its generation resources, the HES with its operational control system, its real-time view and its dynamic decisions making will become an essential part of the integrated energy systems and improve the overall grid reliability. The operational constraints of the energy sources on both the thermal power plants and the non-dispatchable resources in HES, plays a vital role in the planning and design stage. It is an established fact that the choice of energy source depends on the available natural resources and possible infrastructure. A critical component of decision-making depends on the complementary nature and controllability of the energy sources to supply the load demands with high reliability. Controllability of complex HES to achieve desired performance and flexibility is implemented via coordinated control systems while simultaneously generating electricity and other useful products such as useful heat or hydrogen. These systems are based on instrumentation, signal processing, control theory, and engineering system design. The entire HES along with the control systems are characterized by widely varying time constants. Hence, for a well-coordinated control and operation, we propose physics based modeling of the subsystems to assist in a dynamic and transient analysis. Dynamic and transient analysis in real and non-real time domain of the potential sources is capable of providing satisfactory results at the feasibility analysis stage. A simplified HES consisting of complementary energy sources is used to demonstrate the proposed approach. Suitable real time simulations to perform dynamic and transient analysis will be performed to verify results from the non-real time analysis. The role of such analyses, especially the real time dynamic and transient analysis for manual controls is elaborated. It is also discussed that faster than real time simulation will pave the future for controller rooms and hence manual control procedures. Multiple tools such as Real Time Simulator, Matlab®, Simulink®, PSCAD®, MOOSE, etc. are expected to be used for the HES analysis.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2015

Sources of Operational Flexibility, Greening the Grid

Changes in electricity demand and generation must be constantly balanced to maintain power system stability and reliability. Operational flexibility refers to the ability of a power system to respond to these changes. Power systems are designed and operated to efficiently manage variability and uncertainty in electricity demand and resource availability. Variable renewable energy (VRE) increases this inherent variability and uncertainty, and thus increases the need for flexibility. Systems with significant variability and uncertainty require flexible generators that can rapidly change output, operate efficiently at lower outputs, and operate for short durations. This flexibility in turn can reduce the need to curtail (decrease the output of) solar and wind generation; improve investor confidence in VRE and revenue streams; decrease the risk of negative market pricing (which results when conventional generators cannot turn down to low outputs during times of high VRE output); and reduce environmental impacts by increasing system efficiency and maximizing the utilization of VRE.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2019

Drivetrain Reliability from Inherent to Operational

Despite reliability improvements made to wind turbine drivetrains over the years, premature component failures are still challenging the wind industry. There are, however, opportunities to understand drivetrain reliability challenges and investigate potential mitigation solutions. This presentation discusses a few research and development (R&D) activities on drivetrain reliability carried out by the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) over the last ten years. It covers two angles of reliability, inherent and operational, and goes into detail on specific R&D activities. Some inherent reliability challenges covered include gearbox planetary stage loads investigation, high speed shaft and main bearing operational condition understanding, dynamic modeling approaches, and recommended practices. The R&D activities on operational reliability improvements covered include benchmarking, performance and condition monitoring, and predictions on the remaining useful life of components. The presentation concludes with a list of necessary drivetrain reliability improvements that could close the loop between operational and inherent reliability efforts. The team hopes that some of these lessons learned can contribute to relevant international standards or recommended practices.

17 WIND ENERGY↗
DOE OSTI2022

Changes in Hydropower Resource Operations Following Participation in the CAISO Energy Imbalance Market - A Case Study

Portland General Electric (PGE), an investor-owned electric utility serving nearly 900,000 customers in 51 Oregon cities, joined Western Energy Imbalance Market (EIM) – a California Independent System Operator (CAISO) platform for sharing cleaner and more efficient generation resources among multiple states in the Western U.S. While participation in EIM brings a new set of economic opportunities for PGE by capturing flexibility needs in the market, it also changes operational patterns (e.g., more frequent start/stop, off-nominal power output, and ramping) of PGE’s conventional generation fleet, including hydropower units. With 492 MW of hydropower capacity, which constitutes 15\% of PGE’s generation mix, it is important for PGE (as any other EIM-participant utility) to understand how participation in EIM impacts its hydropower assets, and how a techno-economically sustainable operation of those assets could be accomplished. In this paper, a case study is performed with PGE's hydropower generation facilities to assess and quantify EIM-participation driven changes in hydropower operational patterns.

hydropower, operational patterns, energy imbalance↗
DOE OSTI2023

Applying Cyber-Informed Engineering to Power System Operations

This presentation covers the interaction of the discipline of system operations with the growing body of knowledge around Cyber-Informed Engineering (CIE). First is discussion of a number of fundamental concepts for system operators - organizational division of responsibilities, human and machine cooperation, goals, and priorities. The next section covers the reasons why CIE was developed, what it is, and the key design and operational, and organizational principles of CIE. Finally, some thoughts on how CIE can be applied to power system operations are offered, along with some examples of how an organization can approach applying CIE principles in their particular circumstances.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

GOOML - Real World Applications of Machine Learning in Geothermal Operations

GOOML (Geothermal Operational Optimization with Machine Learning) is a machine-learning based framework that enables geothermal power plant operators to explore optimization opportunities for their assets in an efficient and robust digital environment. Backed by real-world data sources, thermodynamic constraints and steamfield intelligence, the GOOML environment provides new tools to explore how to best operate steamfields as well as test new scenarios and configurations prior to implementation in the field. To prove the effectiveness of GOOML, we have undertaken optimization experiments using reinforcement learning (RL) to generate operational suggestions using a balance of mass-take targets, sustainability considerations and net generation. Our experiments use the GOOML construct to explore different field parameters and perform multiple reinforcement learning experiments. Like a comprehensive laboratory workbench, we can change out components of a steamfield to perform testing under a variety of conditions (restrict mass, increase pressure, reroute steam, etc.). This flexibility allows us to explore conditions that would require significant infrastructure changes in a real-world setting at a fraction of the cost and time in a digital environment. The results highlight the benefits of using digital twins and advanced data analytics for the geothermal industry.

forecasting↗
DOE OSTI2023

AI-ENABLED MONITORING OPTIONS TOWARDS SECURE MICROREACTOR DEPLOYMENT AND OPERATIONS

Global nuclear energy deployment scenarios suggest favorable economics for smaller, more versatile, and self-contained reactor technologies. Recognizing their key features as integrated, autonomous and either semi-remotely operated or fully remotely operated systems, microreactors are expected to be deployed in large numbers servicing off/micro-grids, many in geographically remote locations. Integrated nature of these systems as well as ease of their transportation as complete units, simplified installation and relocation/decommissioning challenge traditional continuity-of-knowledge practices used for conventional light water reactors where refueling is done onsite at designated times only replacing portions of their cores and only after their full commissioning for operations including completion of their containment building with security and safeguards measures in place. This effort is exploring AI (artificial intelligence)-enabled monitoring options that would be design agnostic and would assure secure unit deployment and operations. The principle is to maintain situational awareness via real-time evaluations of simultaneous and remotely transmitted monitoring data capturing key safeguards attributes including such characteristics as temperature, radiation, vibrational signals (inter alia), and others. The key principle is to provide reliable and resilient security options while maintaining simplified and economical deployment. The paper will review feasible options for AI-enabled solutions for such evaluations.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2018

Conception and Operation of a New Treatment Center for Radioactive Waste from High Energy Accelerators - 18293

CERN has operated high-energy accelerators for more than 60 years of research in fundamental physics. The side-product of this activity is the generation of low- and intermediate-level radioactive waste, most of which is in solid form and free of surface contamination. Today, one operational year produces about 400 tons of radioactive waste which need to be disposed of towards the final repositories of the two CERN Host States, France and Switzerland. A new facility for the collection, interim storage, characterization and treatment of radioactive waste became operational at CERN in 2015. This facility was specifically conceived for an accelerator complex with a wide range of challenging waste items, which are often unique in their irradiation history as well as in their physical, chemical and radiological characteristics. The disposal rate was ramped up in 2016 with a unique treatment process tailored for metallic low-level waste. In 2017, two parallel processes were successfully tested for the elimination of radioactive cables and for the recycling of valuable metals. This paper gives an overview of the challenges in the design, commissioning and operation of the CERN radioactive waste treatment center. It outlines the methodology followed for the conception of the elimination processes, which can be of guidance for the development of similar facilities. (authors)

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

Peculiarities of Transition from Operation to Decommissioning for the Chernobyl NPP - 18486

Usually the transition period is supposed to last around 5 years and to cover the eventual defueling of the reactor and the reactor cooling pool, completion of the characterization survey and preparation of all necessary documents to start the decommissioning activities in accordance with the decommissioning strategy chosen and the decommissioning plan approved. It was not the case for the Chernobyl NPP due to a number of reasons and obstacles, including delayed defueling due to unavailability of the storage capacities, lack of preparatory work due to prescheduled decommissioning, luck of experience of RBMK-type reactors decommissioning, influence of the destroyed Chernobyl-4 Unit and related works on site. All these factors not only delayed the completion of the characterization survey, but added complications to development of the decommissioning strategy and the decommissioning plan. De facto the issue of end state is still open as the end state for the destroyed Chernobyl-4 as well as the prospects of the exclusion zone transformation need further clarifications and justifications. As a result, the need to reconsider the standard concept of transition period was recognized already by the end of 2000, when Chernobyl-1 and Chernobyl-2 were out of operation for a few years. It was clear that the personnel had generally a bad perception of the prescheduled permanent shutdown decision and a low motivation to change and to learn. The first signs of organizational degradation were visible and the framework of the operational license did not fit well to prevent it. So it was decided to start the legal and organizational transformation into the decommissioning mode without waiting for polishing of the decommissioning strategy and decommissioning plan as in this case both documents seemed to need further adjustments anyway. The transition period (or the termination of operation as it called in the national nuclear safety regulations) was considered as the first phase of decommissioning to be covered by the decommissioning license. The detailed plan of activities for the transition period with proper safety justification documents was the main part of the relevant license application. Human resource management plan and adoption of the management system were important constituents as well. It was also considered reasonable to start some dismantling works already at this phase to avoid further delays and degradation, the works being carefully justified. Eventually such approach added to streamlining the decommissioning process and to avoid further organizational and technical degradation. Flexibility in transition from operation to decommissioning seems necessary in cases of prescheduled or post-accidental decommissioning but may be also beneficial for a scheduled decommissioning case. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Concept for Operation of the Belgian Geological Disposal Facility for Category B and C Wastes - 19247

For more than 40 years, ONDRAF/NIRAS (the federal agency responsible for managing radioactive waste and enriched fissile materials in Belgium) has been studying the concept of a geological disposal facility (GDF) in poorly indurated clays as an option for the long-term management of both category B waste (low-level and intermediate-level long-lived waste - LILW-LL) and category C waste (high-level waste - HLW and spent fuel). In the absence of a policy decision, the proposed Belgian reference option for disposal of such waste is a GDF in poorly indurated clays, located at a depth of between 200 m and 600 m. Within the framework of the first Safety and Feasibility Case (SFC-1) undertaken by ONDRAF/NIRAS, the organization is updating its former GDF layout, which dates back from 2003. The SFC-1 GDF concept is characterized by a central zone in which shafts, joined by a central connecting gallery, provide two surface connections. On opposing sides of the central gallery, four (two on each side) access galleries branch off to connect the disposal areas for B- and C-waste, respectively. Disposal dead end galleries, 400 m long, branch off perpendicular to the access galleries. Both waste areas will be operated during two separate time frames. The current underground layout has been significantly modified from the previous 2003 layout. The modifications are largely based on several R and D studies with regard to the future operations of the GDF carried out by BGE Technology GmbH in support to ONDRAF/NIRAS. This paper focuses on major operational processes such as waste transport and emplacement. In addition, the current conceptual design of the backfilling and closure concept is presented. Optimization studies on the further development of the operational process are also presented. (authors)

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

Assessment of Reactor BN-350 Impact on the Environment During Its Operation Period

Fast neutron reactor BN-350 was designed for dual purposes: steam production and plutonium generation. The steam produced in the reactor was used to generate electricity (150 MW) and desalination of seawater (up to 120 000 tons/day). The BN-350 reactor began operating in July 1973 with a design lifetime of 20 years. After the end of the reactor design lifetime in July 1993, its further operation was managed on the basis of annual decisions taken to extend the operating life for one year. The reactor was in downtime beginning in December 1998 and on 22 April 1999 the RK Government Resolution no. 456 'About decommissioning of the BN-350 reactor in Aktau, Mangistau region' was adopted. Thus, the total actual reactor operational period was more than 25 years. In the framework of work under the approved 'Plan of priority measures for decommissioning of the BN-350 reactor in Aktau', the specialists of the Institute of Nuclear Physics (INP) and the Mangystau Nuclear Power Complex performed a radiation survey of the plant area, the sanitary protection zone and reactor BN-350 monitoring area. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

SIT Makeup Effect on the Loss of Residual Heat Removal during Mid-loop Operation

For the loss of cooling during the mid-loop operation, the plant needs to have a sufficient time for operator action without active makeup measures such as a loss of alternating current (AC) power. This concern is raised after the Fukushima accident. Especially, in addition to the loss of residual heat removal (LORHR), if the AC power or active makeup measures are unavailable, the passive makeup using gravity feed or pressurized feed will provide sufficient time before core uncovery. This paper investigates means of the passive makeup measures using safety injection tank (SIT) after the LORHR event to prevent or delay the core uncovery and fuel failure for the typical advanced power reactor 1400 (APR1400). Unfortunately, the refueling water storage tank of APR1400 cannot be used for gravity makeup since it is located on the bottom of the containment with a lower elevation than the reactor vessel. So, the SIT makeup and the effect on the core uncovery are investigated. The results show that gravity makeup of a SIT provides insufficient means but the slightly pressurized SIT is required for sufficient operator action time for the LORHR with the station black out (SBO) during the mid-loop operation for the APR1400. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2024

Deep Nonparametric Estimation of Operators between Infinite Dimensional Spaces

Learning operators between infinitely dimensional spaces is an important learning task arising in machine learning, imaging science, mathematical modeling and simulations, etc. This paper studies the nonparametric estimation of Lipschitz operators using deep neural networks. Non-asymptotic upper bounds are derived for the generalization error of the empirical risk minimizer over a properly chosen network class. Under the assumption that the target operator exhibits a low dimensional structure, our error bounds decay as the training sample size increases, with an attractive fast rate depending on the intrinsic dimension in our estimation. Our assumptions cover most scenarios in real applications and our results give rise to fast rates by exploiting low dimensional structures of data in operator estimation. We also investigate the influence of network structures (e.g., network width, depth, and sparsity) on the generalization error of the neural network estimator and propose a general suggestion on the choice of network structures to maximize the learning efficiency quantitatively.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

Risk-Informed Operations and Maintenance Decision Making Using Deep Reinforcement Learning

A challenge for operating nuclear power plants is the significant cost of operations and maintenance, at times consuming up to 66% of annual operating costs. This project aims to build a framework for a risk-informed asset-management tool that integrates inspections, repairs, spare-part inventory, supply chain, and business choices to lower overall O&M costs. Our approach uses a combination of data-driven modeling and deep reinforcement learning to create and implement optimal maintenance policies for the existing nuclear fleet, as well as new advanced reactors. The creation of an asset management tool that uses these advanced methods will give operators new capabilities to help reduce the burden of O&M spending in nuclear power plants.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2023

Simultaneous Enhancement of Efficiency And Operational-Stability of Mesoscopic Perovskite Solar Cells via Interfacial Toughening

The combined effects of compact TiO 2 (c-TiO 2 ) electron-transport layer (ETL) are investigated without and with mesoscopic TiO 2 (m-TiO 2 ) on top, and without and with an iodine-terminated silane self-assembled monolayer (SAM), on the mechanical behavior, opto–electronic properties, photovoltaic (PV) performance, and operational-stability of solar cells based on metal-halide perovskites (MHPs). The interfacial toughness increases almost threefold in going from c-TiO 2 without SAM to m-TiO 2 with SAM. This is attributed to the synergistic effect of the m-TiO 2 /MHP nanocomposite at the interface and the enhanced adhesion afforded by the iodine-terminated silane SAM. The combination of m-TiO 2 and SAM also offers a significant beneficial effect on the photocarriers extraction at the ETL/MHP interface, resulting in perovskite solar cells (PSCs) with power-conversion efficiency (PCE) of over 24% and 20% for 0.1 and 1 cm 2 active areas, respectively. These PSCs also have exceptionally long operational stability lives extrapolated T80 (duration at 80% initial PCE retained) is ≈18 000 and 10 000 h for 0.1 and 1 cm 2 active areas, respectively. In conclusion, postmortem characterization and analyses of the operational-stability-tested PSCs are performed to elucidate the possible mechanisms responsible for the long operational-stability.

14 SOLAR ENERGY↗
DOE OSTI2020

Optimal economic operation of liquid petroleum products pipeline systems

The majority of overland transport needs for crude petroleum and refined petroleum products are met using pipelines. Numerous studies have developed optimization methods for design of these systems in order to minimize construction costs while meeting capacity requirements. Here, we formulate problems to optimize the operations of existing single liquid commodity pipeline systems subject to physical flow and pump engineering constraints. The objectives are to maximize the economic value created for users of the system and to minimize operating costs. We present a general computational method for this class of continuous, non-convex nonlinear programs, and examine the use of pump operating settings and flow allocations as decision variables. Furthermore, the approach is applied to compute optimal operating regimes and perform engineering economic sensitivity analyses for a case study of a crude oil pipeline developed using publicly available data.

02 PETROLEUM↗