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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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Cyber Conservative Operations

In an era of increasingly sophisticated and pervasive cyber threats, robust cyber resilience strategies are more critical than ever. This paper introduces the concept of Cyber Conservative Operations, a proactive approach designed to assist critical infrastructure owners and operators in managing risk and maintaining resilience in the face of imminent, yet not occurring, cyber events. By leveraging the principles of Cyber-Informed Engineering (CIE) and the energy sector’s practice of conservative operations, Cyber Conservative Operations offer a framework for planning and executing coordinated active defense and resilience-oriented actions ahead of cyber events. This approach aims to minimize the consequences of digitally-enabled hazards and ensure swift recovery from anticipated cyber threats. Cyber Conservative Operations enhance the ability of owners and operators to execute pre-planned defense and resilience actions, thereby reducing the impact of digitally-enabled hazards. These operations are crucial for addressing impacts that cannot be precisely quantified or forecasted and for preparing organizations for rapid recovery from imminent digital threats. The paper begins with a discussion of conservative operations as applied to the bulk power system (BPS), a current mechanism allowing BPS entities to enact defensive operating plans to mitigate impending grid unreliability. Building on this model, we present a concept for implementing cyber conservative operations at asset owner facilities. The paper concludes with two case studies of cyber conservative operations drawn from high-profile cyber events, illustrating the practical application and benefits of this proactive approach.

42 - ENGINEERING↗
DOE OSTI2022

RHIC Run 22, 9 o'clock, a Snake in the Blue

The simulations detailed in this Tech. Note were aimed at determining new RHIC Blue 9 o’clock snake coil current and local closed orbit bump settings, together with updated - optimized - 3 o’clock snake settings, in order to recover from power supply dips which, early in the run (December 2021), caused the failure of 9 o’clock snake’s second coil in a first occurrence, and of its fourth coil in addition in a second occurrence, leaving the poor animal with just its coils 1 and 3. Documentation from a similar incident in Yellow in 2003 could be leaned on and allowed to promptly figure various necessary measures for swift recovery using the 9 o’clock Blue snake coils which survived the dip. Reference reports in particular that, in this 2003 incident, “[it was] decided to run the [failed] snake as a 88% partial snake while keeping the angles between the two snakes as 90° [...]. In general, the polarization level was not as good as Blue ring”. By contrast in this Run 22 incident, thorough simulations using the snake OPERA field maps helped determine new settings of the handicapped, 2-coil, Blue ring 9 o’clock snake currents and local closed orbit bump, and concurrently determine slight adjustment of the 3 o’clock snake currents, which allowed recovering full polarization at store, as good as could be expected from normal operation - even better over extended periods than in the Yellow ring.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Black Start of Unbalanced Microgrids Harmonizing Single- and Three-Phase Grid-Forming Inverters

As power systems are transforming with increasing penetrations of inverter-based resources (IBRs), system restoration using IBRs has drawn attention. Using distributed grid-forming (GFM) assets located near critical loads, either three-phase or single-phase, to establish microgrid voltages in the absence of a bulk grid, a distribution system could obtain high system survivability. For swift and secure recovery of a critical load in a single-phase lateral, local single-phase GFM inverters can form a microgrid, and then it can be combined with a neighbouring grid with the inverters remaining in GFM mode for voltage and frequency regulation until the bulk grid comes online. It leads to dynamic interoperation of single-phase GFM inverters with three-phase ones in the black start process. This paper studies the novel approach with electromagnetic transient (EMT) simulations. To evaluate the potential and the technical challenges of the heterogeneous IBR-driven black start, three-phase and single-phase GFM inverter models are developed, including negative-sequence control for voltage balance and a phase-by-phase current limiter (three-phase) and current magnitude limiter (single-phase). To examine dynamic aspects of the black-start process, the EMT simulation also models transformer and motor dynamics emulating their inrush and startup behavior as well as network dynamics. Involvement of grid-following assets to facilitate the black-start process is also modeled. By allowing multiple GFM inverters to collectively black start without leader-follower coordination, regardless of phases, a system can achieve extreme resilience. An inverter-driven black start of a heavily unbalanced 2-MVA distribution feeder using 1 three-phase and 3 single-phase GFM inverters is demonstrated. The simulation shows the heterogeneous system can maintain stability with the single-phase GFM dynamics coupled with the three-phase one.

grid-forming inverter↗
DOE OSTI2023

Black Start of Unbalanced Microgrids Harmonizing Single- and Three-Phase Grid-Forming Inverters: Preprint

As power systems are transforming with increasing penetrations of inverter-based resources (IBRs), system restoration using IBRs has drawn attention. Using distributed grid-forming (GFM) assets located near critical loads, either three-phase or single-phase, to establish microgrid voltages in the absence of a bulk grid, a distribution system could obtain high system survivability. For swift and secure recovery of a critical load in a single-phase lateral, local single-phase GFM inverters can form a microgrid, and then it can be combined with a neighbouring grid with the inverters remaining in GFM mode for voltage and frequency regulation until the bulk grid comes online. It leads to dynamic interoperation of single-phase GFM inverters with three-phase ones in the black start process. This paper studies the novel approach with electromagnetic transient (EMT) simulations. To evaluate the potential and the technical challenges of the heterogeneous IBR-driven black start, three-phase and single-phase GFM inverter models are developed, including negative-sequence control for voltage balance and a phase-by-phase current limiter (three-phase) and current magnitude limiter (single-phase). To examine dynamic aspects of the black-start process, the EMT simulation also models transformer and motor dynamics emulating their inrush and startup behavior as well as network dynamics. Involvement of grid-following assets to facilitate the black-start process is also modeled. By allowing multiple GFM inverters to collectively black start without leader-follower coordination, regardless of phases, a system can achieve extreme resilience. An inverter-driven black start of a heavily unbalanced 2-MVA distribution feeder using 1 three-phase and 3 single-phase GFM inverters is demonstrated. The simulation shows the heterogeneous system can maintain stability with the single-phase GFM dynamics coupled with the three-phase one.

grid-forming inverter↗
DOE OSTI2015

Damage correlations in semiconductor devices exposed to gamma and high energy swift heavy ions

NPN rf power transistors and N-channel depletion MOSFETs are irradiated by different high energy swift heavy ions and {sup 60}Co gamma radiation in the dose range of 100 krad to 100 Mrad. The damage created by different heavy ions and {sup 60}Co gamma radiation in NPN rf power transistors and N-channel depletion MOSFETs have been correlated and studied in the same dose range. The recoveries in the electrical characteristics of different swift heavy ions and {sup 60}Co gamma irradiated devices have been studied after annihilation.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Ionization-induced thermally activated defect-annealing process in SiC

Ionizing events can lead to panoply of irradiation effects, and in silicon carbide (SiC), they drastically modify the defect production rate or the initial density. To better comprehend this phenomenon, 6H-SiC single crystals were first predamaged using low-velocity 100-keV Fe + ions at three fluences in the range of 10 14 cm -2 to induce three different initial disorder levels peaking at values between ~0.8 and 1 (1 corresponding to full amorphization). Crystals were then submitted to swift heavy ion irradiation in the 10 13 cm -2 fluence range at both low (~100 K) and high (~770 K) temperature. Rutherford backscattering spectrometry in channeling conditions revealed that swift ions allow annealing part of the initial damage, the recovery efficiency increasing with the irradiation temperature and reaching 75% in initially severely disordered crystals. This temperature effect has been qualitatively predicted by molecular dynamics simulations. Transmission electron microscopy allowed imaging both the recovery and the difference in the microstructure of the layers irradiated at low or high temperature. Recovery cross sections are discovered to lie in the range of a few square nanometers, consistent with previously reported values. A scenario for a general, two-step annealing mechanism referred to as an ionization-activated, thermally assisted defect-annealing (IATADA) process is proposed. This mechanism rationalizes the diverse descriptions reported so far in the literature.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Real-Time Optimized Load Recovery Considering Frequency Constraints

A self-healing power grid can mitigate the impact of power outages and recover the affected area swiftly. To properly size the optimal amount and location of de-energized loads in the presence of both conventional and renewable sources, a precise optimization-based load recovery tool is proposed herein. The steady-state and transient behaviors of loads have been taken into account. The proposed tool contains three separate problems that interact with each other during the restoration period. The first-level problem determines the dispatching of generation units. The second-level problem comprises the non-linear algebraic equations, whose task is to provide the initial conditions for the third-level problem. Finally, the third-level problem intends to determine the optimal location and amount of load pickup through modeling the governor of generators as well as loads' dynamic behaviors. To examine the effectiveness of the proposed tool, a modified IEEE 39-system under a partial blackout condition has been tested. The results are verified by a commercial time-domain simulation software (PSS/E) to demonstrate the accuracy of the proposed approach. Ultimately, the impact of wind turbine frequency control on the load recovery process has been studied under different penetration levels.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2020

Key Accomplishments & Results: Sustainable Wastewater Infrastructure of the Future

This fact sheet summarizes the key accomplishments and results from DOE's Better Buildings Sustainable Wastewater Infrastructure of the Future (SWIFt) Accelerator. The Accelerator was a 3-year effort between DOE and state and local jurisdictions to promote energy data management practices in wastewater operations in an effort to increase energy efficiency in wastewater facilities around the country. Accelerator participants shared implementation plans, and DOE combined the results into a final toolkit.

wastewater, water resource recovery facilities, en↗
DOE OSTI2017

Thermal defect annealing of swift heavy ion irradiated ThO 2

Neutron total scattering and Raman spectroscopy were used to characterize the structural recovery of irradiated polycrystalline ThO 2 (2.2 GeV Au, = 1 x 10 13 ions/cm 2 ) during isochronal annealing. Here, neutron diffraction patterns showed that the Bragg signal-to-noise ratio increases and the unit cell parameter decreases as a function of isochronal annealing temperature, with the latter reaching its pre-irradiation value by 750 °C. Diffuse neutron scattering and Raman spectroscopy measurements indicate that an isochronal annealing event occurs between 275$-$425 °C. This feature is attributed to the annihilation of oxygen point defects and small oxygen defect clusters.

36 MATERIALS SCIENCE↗
DOE OSTI2015

In situ defect annealing of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell

Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron Xray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performing in situ defect annealing and thermal expansion studies of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction. The advantages of the in situ HDAC technique over conventional annealing methods include: rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature- and apparatus stability at high temperatures. Isochronal annealing between 300 K and 1100 K revealed 2-stage and 1-stage defect recovery processes for irradiated CeO 2 and ThO 2 , respectively; indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high temperature defect recovery mechanisms of CeO 2 and ThO 2 .

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

Implementation and Validation of a Generalized Actuator Disk Parameterization for Wind Turbine Simulations Within the FastEddy Model

ABSTRACT Fast and accurate large‐eddy simulation (LES) of the atmospheric boundary layer plays a crucial role in advancing wind energy research. Long‐duration wind farm studies at turbine‐resolving scales have become increasingly important to understand the intricate interactions between large wind farms and the atmospheric boundary layer. However, the prohibitive computational cost of these turbulence‐ and turbine‐resolving simulations has precluded such modeling to be exercised on a regular basis. To that end, we implement and validate the generalized actuator disk (GAD) model in the computationally efficient, graphics processing unit (GPU)–resident, LES model FastEddy. We perform single‐turbine simulations under three atmospheric stabilities (neutral, unstable, and stable) and compare them against observations from the Scaled Wind Farm Technology (SWiFT) facility and other LES codes from the recent Wakebench turbine wake model benchmark. Our idealized LES results agree well with observed wake velocity deficit and downstream recovery across stability regimes. Turbine response in terms of rotational speed, generated power, torque, and thrust coefficient are well predicted across stability regimes and are consistent with the LES results from the benchmark. The FastEddy simulations are found to be at least two orders of magnitude more efficient than the traditional CPU‐based LES models, opening the door for realistic LES simulations of full wind plants as a viable standard practice.

17 WIND ENERGY↗
DOE OSTI2014

The long-term post-outburst spin down and flux relaxation of magnetar swift J1822.3–1606

The magnetar Swift J1822.3–1606 entered an outburst phase in 2011 July. Previous X-ray studies of its post-outburst rotational evolution yielded inconsistent measurements of the spin-inferred magnetic field. Here we present the timing behavior and flux relaxation from over two years of Swift, RXTE, and Chandra observations following the outburst. We find that the ambiguity in previous timing solutions was due to enhanced spin down that resembles an exponential recovery following a glitch at the outburst onset. After fitting out the effects of the recovery, we measure a long-term spin-down rate of ν-dot =(−3.0 ± 0.3)×10{sup −16} s{sup –2} which implies a dipolar magnetic field of 1.35 × 10{sup 13} G, lower than all previous estimates for this source. We also consider the post-outburst flux evolution, and fit it with both empirical and crustal cooling models. We discuss the flux relaxation in the context of both crustal cooling and magnetospheric relaxation models.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Recovery effects due to the interaction between nuclear and electronic energy losses in SiC irradiated with a dual-ion beam

Single and dual-beam ion irradiations of silicon carbide (SiC) were performed to study possible Synergetic effects between Nuclear (S{sub n}) and Electronic (S{sub e}) Energy Losses. Results obtained combining Rutherford backscattering in channeling conditions, Raman spectroscopy, and transmission electron microscopy techniques show that dual-beam irradiation of SiC induces a dramatic change in the final sample microstructure with a substantial decrease of radiation damage as compared to single-beam irradiation. Actually, a defective layer containing dislocations is formed upon dual-beam irradiation (S{sub n} and S{sub e}), whereas single low-energy irradiation (S{sub n} alone) or even sequential (S{sub n} + S{sub e}) irradiations lead to full amorphization. The healing process is ascribed to the electronic excitation arising from the electronic energy loss of swift ions. These results shed new light on the long-standing puzzling problem of the existence of a possible synergy between S{sub n} and S{sub e} in ion-irradiation experiments. This work is interesting for both fundamental understanding of the ion-solid interactions and technological applications in the nuclear industry where recovery S{sub n}/S{sub e} effects may preserve the integrity of nuclear devices.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Ion Tracks and Microstructures in Barium Titanate Irradiated with Swift Heavy Ions: A Combined Experimental and Computational Study

Tetragonally structured BaTiO3 single crystals were irradiated using 635 MeV 238U+ ions to fluences of 1E7, 5E10 and 1.4E12 ions/cm2 at room temperature. Subsequent sample characterizations were performed using ion channeling, x-ray diffraction (XRD), helium ion microscopy, and transmission electron microscopy. The results show that there are lattice relaxation and recovery of pre-existing defects in the irradiated samples. Various structures representing different regimes of electronic and nuclear interactions along the ion track are observed. The track on the surface has an amorphous core of up to ~10 nm in diameter, surrounded by a strained lattice structure. The core size is roughly proportional to the square root of the electronic stopping power. Satellite-like defects around the core are also present. The ring of cubic phase expected to form around the amorphous core does not appear, probably due to a reversible phase transition as confirmed by an in-situ XRD study. Modeling and simulation are also attempted to interpret the data and gain physical insights. We have developed a partial charge model for cubic BaTiO3 that reproduces its lattice constants, elastic constants, and melting temperature. Using the interatomic potential, we have performed molecular dynamics simulations of the irradiation damage in BaTiO3. The results show that an amorphous track of ~1.2 nm in radius forms under thermal energy deposition at dE(T)/dx = 5 keV/nm. At 20 keV/nm, the radius increases to ~4.5 nm with an order of magnitude increase in the number of defects. The simulation also reveals details of the bonding environments and shows that the amorphous zones produced at different dE(T)/dx values have different densities. The combined experimental and computational data suggest that there is a significant interfacial recrystallization of the as-created amorphous cores during the cooling-down stage of thermal spikes.

barium titanate↗