Results for “Hydrogen Production” — Page 40

DOE OSTI1993

Nuclear Safety [Vol. 34, No. 1, January-March 1993]

Nuclear Safety is a review journal that covers significant developments in the field of nuclear safety. Its scope includes the analysis and control of hazards associated with nuclear energy, operations involving fissionable materials, and the products of nuclear fission and their effects on the environment. Primary emphasis is on safety in reactor design, construction, and operation; however, the safety aspects of the entire fuel cycle, including fuel fabrication, spent-fuel processing, nuclear waste disposal, handling of radioisotopes, and environmental effects of these operations, are also treated. Table of Contents for this issue follows. GENERAL SAFETY CONSIDERATIONS: 1 An Integrated Regional Approach To Risk Management of Industrial Systems, S. Chakraborty and R. Stratton; 9 Annual Technical Meeting of the NRC Cooperative Severe Accident Research Program, E. G. Silver; ACCIDENT ANALYSIS: 13 Deterministic Severe Accident Criteria as Severe Accident Design Criteria and Policy for the New Production Reactor-Heavy Water Reactor, P. T. Rhoads; 20 Proposed Deterministic Severe Accident Criteria for the Heavy Water Reactor-New Production Reactor Containment, K. D. Bergeron, S. E. Slezak, and C. E. Leach; 33 Quasi-Static Core Liquid Level Depression and Long-Term Core Uncovery During a PWR LOCA, Y. Kukita, R. R. Schultz, H. Nakamura, and J. Katayama; 49 LIRA: An Advanced Containment System to Minimize the Accidental Radioactivity Releases, A. Turricchia; 63 Errata to “A Review of Hydrogen Production During Melt/Water Interaction in LWRs,” Vol. 33, No. 4; CONTROL AND INSTRUMENTATION: 64 The Nuplex 80+™ Advanced Control Complex from ABB Combustion Engineering, F. Ridolfo, D. Harmon, and K. Scarola; DESIGN FEATURES: 76 A Scheme for Passive Isolation of the Containment of a Reactor, A. K. Ghosh, V. V. Raj, and K. Kakodkar; 84 Utility Requirements for Safety in the Passive Advanced Light-Water Reactor, T. U. Marston, W. H. Layman, and G. Bockhold, Jr.; WASTE AND SPENT FUEL MANAGEMENT: 91 Activities Related to Waste and Spent Fuel Management, Compiled by M. D. Muhlheim and E. G. Silver; OPERATING EXPERIENCES: 103 Testing Deficiencies in Auxiliary Systems Feedwater Systems, J. D. Kueck; 110 Reactor Shutdown Experience, Compiled by J. W. Cletcher; 113 Selected Safety-Related Events, Compiled by G. A. Murphy; 115 Operating U.S. Power Reactors, Compiled by M. D. Muhlheim and E. G. Silver; RECENT DEVELOPMENTS: 133 General Administrative Activities, Compiled by M. D. Muhlheim and E. G. Silver; 145 Reports, Standards, and Safety Guides, D. S. Queener; 150 Proposed Rule Changes as of Sept. 30, 1992; ANNOUNCEMENTS: 75 Harvard Short Course on Risk: Science, Assessment, and Management; 102 International Conference on Reactor Physics and Reactor Computations; 102 The Fourth International Conference on Nuclear Waste Reprocessing and Waste Management [RECOD ’94]; 132 International Symposium on the Radiological Exposure of the Population of the European Community from Radioactivity in the Mediterranean Sea [MARINA-MED]; 162 International High-Level Radioactive Waste Conference ‘Technology Integration—Above and Below”; 154 The Authors; 158 Indexes to Nuclear Safety, Volume 33.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI1993

Nuclear Safety [Vol. 34, No. 1, January-March 1993]

Nuclear Safety is a review journal that covers significant developments in the field of nuclear safety. Its scope includes the analysis and control of hazards associated with nuclear energy, operations involving fissionable materials, and the products of nuclear fission and their effects on the environment. Primary emphasis is on safety in reactor design, construction, and operation; however, the safety aspects of the entire fuel cycle, including fuel fabrication, spent-fuel processing, nuclear waste disposal, handling of radioisotopes, and environmental effects of these operations, are also treated. Table of Contents for this issue follows. GENERAL SAFETY CONSIDERATIONS: 1 An Integrated Regional Approach To Risk Management of Industrial Systems, S. Chakraborty and R. Stratton; 9 Annual Technical Meeting of the NRC Cooperative Severe Accident Research Program, E. G. Silver; ACCIDENT ANALYSIS: 13 Deterministic Severe Accident Criteria as Severe Accident Design Criteria and Policy for the New Production Reactor-Heavy Water Reactor, P. T. Rhoads; 20 Proposed Deterministic Severe Accident Criteria for the Heavy Water Reactor-New Production Reactor Containment, K. D. Bergeron, S. E. Slezak, and C. E. Leach; 33 Quasi-Static Core Liquid Level Depression and Long-Term Core Uncovery During a PWR LOCA, Y. Kukita, R. R. Schultz, H. Nakamura, and J. Katayama; 49 LIRA: An Advanced Containment System to Minimize the Accidental Radioactivity Releases, A. Turricchia; 63 Errata to “A Review of Hydrogen Production During Melt/Water Interaction in LWRs,” Vol. 33, No. 4; CONTROL AND INSTRUMENTATION: 64 The Nuplex 80+™ Advanced Control Complex from ABB Combustion Engineering, F. Ridolfo, D. Harmon, and K. Scarola; DESIGN FEATURES: 76 A Scheme for Passive Isolation of the Containment of a Reactor, A. K. Ghosh, V. V. Raj, and K. Kakodkar; 84 Utility Requirements for Safety in the Passive Advanced Light-Water Reactor, T. U. Marston, W. H. Layman, and G. Bockhold, Jr.; WASTE AND SPENT FUEL MANAGEMENT: 91 Activities Related to Waste and Spent Fuel Management, Compiled by M. D. Muhlheim and E. G. Silver; OPERATING EXPERIENCES: 103 Testing Deficiencies in Auxiliary Systems Feedwater Systems, J. D. Kueck; 110 Reactor Shutdown Experience, Compiled by J. W. Cletcher; 113 Selected Safety-Related Events, Compiled by G. A. Murphy; 115 Operating U.S. Power Reactors, Compiled by M. D. Muhlheim and E. G. Silver; RECENT DEVELOPMENTS: 133 General Administrative Activities, Compiled by M. D. Muhlheim and E. G. Silver; 145 Reports, Standards, and Safety Guides, D. S. Queener; 150 Proposed Rule Changes as of Sept. 30, 1992; ANNOUNCEMENTS: 75 Harvard Short Course on Risk: Science, Assessment, and Management; 102 International Conference on Reactor Physics and Reactor Computations; 102 The Fourth International Conference on Nuclear Waste Reprocessing and Waste Management [RECOD ’94]; 132 International Symposium on the Radiological Exposure of the Population of the European Community from Radioactivity in the Mediterranean Sea [MARINA-MED]; 162 International High-Level Radioactive Waste Conference ‘Technology Integration—Above and Below”; 154 The Authors; 158 Indexes to Nuclear Safety, Volume 33.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2024

System design and analysis of thermal power dispatch systems for boiling water reactors

Nuclear power plants are crucial to meeting net zero emission goals and achieving energy sustainability. Integrating these plants with clean energy technologies such as high-temperature steam electrolysis (HTSE) may improve the efficiency and economic competitiveness of these plants. Here, the current study investigates the design and operation of a thermal power dispatch (TPD) system for coupling boiling water reactors (BWRs) to HTSE plants. The TPD system extracts a portion of the steam from the reactor’s main steam line and transfers its thermal energy to an HTSE plant through a power transport loop. A TPD system for 5 % steam extraction has been designed and the system performance during steady and transient operations has been analyzed. The TPD system dispatched a total of 197 MW thermal energy to the HTSE plant under nominal design conditions. Saturated steam at 7.17 MPa from the BWR plant was condensed and subcooled to a temperature of 168 °C, while a mass flow rate of 91.1 kg/s of superheated steam was dispatched to the HTSE plant. Furthermore, the system performance during transient operation showed a continuous transition from the initial hot standby mode to the nominal power dispatch level. The transient simulation results emphasized the importance of investigating component level performance for the TPD system design. The current results will guide future works on the development of integrated energy systems for hydrogen production or process heat applications.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2024

Stable water splitting using photoelectrodes with a cryogelated overlayer

Hydrogen production techniques based on solar-water splitting have emerged as carbon-free energy systems. Many researchers have developed highly efficient thin-film photoelectrochemical (PEC) devices made of low-cost and earth-abundant materials. However, solar water splitting systems suffer from short lifetimes due to catalyst instability that is attributed to both chemical dissolution and mechanical stress produced by hydrogen bubbles. A recent study found that the nanoporous hydrogel could prevent the structural degradation of the PEC devices. In this study, we investigate the protection mechanism of the hydrogel-based overlayer by engineering its porous structure using the cryogelation technique. Tests for cryogel overlayers with varied pore structures, such as disconnected micropores, interconnected micropores, and surface macropores, reveal that the hydrogen gas trapped in the cryogel protector reduce shear stress at the catalyst surface by providing bubble nucleation sites. The cryogelated overlayer effectively preserves the uniformly distributed platinum catalyst particles on the device surface for over 200 h. Our finding can help establish semi-permanent photoelectrochemical devices to realize a carbon-free society.

42 ENGINEERING↗

DOE OSTI2022

Impacts of ruthenium valence state on the electrocatalytic activity of ruthenium ion-complexed graphitic carbon nitride/reduced graphene oxide nanosheets towards hydrogen evolution reaction

Design and engineering of effective electrode catalysts represents a critical first step for hydrogen production by electrochemical water splitting. Nanocomposites based on ruthenium atomically dispersed within a carbon scaffold have emerged as viable candidates. In the present study, ruthenium metal centers are atomically embedded within graphitic carbon nitride/reduced graphene oxide nanosheets by thermal refluxing. Subsequent chemical reduction/oxidation leads to ready manipulation of the ruthenium valence state, as evidenced in microscopic and spectroscopic measurements, and hence enhancement/diminishment of the electrocatalytic activity towards hydrogen evolution reaction in both acidic and alkaline media. Further, this is largely ascribed to the increased/reduced contribution of the Ru valence electrons to the density of state near the Fermi level which dictates the binding and reduction of hydrogen. Results from this study highlight the significance of the valence state of metal centers in the manipulation and optimization of the catalytic performance of single atom catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRS1977

Competitively priced hydrogen via high-efficiency nuclear electrolysis

A fully dedicated nuclear-electrolytic hydrogen-production facility, based on advanced (1985) technology, has been synthesized and assessed at the conceptual level. The facility integrates an HTGR operating a binary shaftpower-extraction cycle at 980 C top temperature, direct dc electricity generation via acyclic generators, and high-current density high-pressure electrolyzers based on the solid polymer electrolyte approach. All subsystems are close-coupled and optimally interfaced. Pipeline-pressure hydrogen and coproduct oxygen are produced at 6900 kPa. On consistent costing bases, the advanced facility concept was found to provide hydrogen costs that were approximately half those associated with conventional, contemporary-technology nuclear electrolysis. The nuclear heat-to-hydrogen energy conversion efficiency for the advanced system was estimated as 43%, against 25% for the baseline present-day approach.

Escher, W. J. D.↗

DOE OSTI2024

ARIES / Flatirons Facility - Hydrogen System Capability Buildout

Under the "Advanced Research on Integrated Energy Systems" (ARIES) initiative, hydrogen system capabilities including a MW-scale electrolyzer, storage system, and MW-scale fuel cell generator will be designed and commissioned at NREL's Flatirons Campus. This hydrogen infrastructure will support H2@Scale goals by enabling integrated systems R&D to study the science of scaling for hydrogen energy systems.The system is designed with flexibility to provide a testbed to demonstrate systems integration, grid services, energy storage, direct renewable hydrogen production, and innovative end use applications (e.g. HD transportation, natural gas blending, etc.).

electrical grid↗

DOE OSTI2025

Advancing Photo(Electro)Chemical Water Splitting: The Promise of Atomically Dispersed Single‐, Dual‐, and Alloy‐Site Catalysts

Single-atom catalysts (SACs) have rapidly gained prominence as an emerging class of electrocatalysts for water splitting, owing to their uniform and precisely defined active sites. By maintaining uniform reaction pathways, SACs minimize the formation of unwanted byproducts, thus exhibiting extremely high selectivity and atomic efficiency. A key determinant of SAC performance lies in the interfacial interaction between the isolated metal atoms and the supporting material under strong metal–support coordination, which is vital for maintaining long-term activity. However, despite these benefits, reproducibly synthesizing SACs with high metal loadings while retaining uniform dispersion remains a significant challenge. To address the intrinsic challenges of SACs, recent research has expanded into dual-atom catalysts (DACs) and single-atom alloy catalysts (SAACs), providing synergistic active sites and combining the benefits of SACs with bimetallic systems. Furthermore, this review systematically explores the latest advancements in synthesis methods and innovations for SACs for electrochemical water splitting. Additionally, it examines the evolution of catalyst design, emphasizing the unique structural and electronic characteristics of single-site, dual-site, and alloyed SAC systems and highlighting their critical roles in accelerating water-splitting reaction kinetics as well as the prevailing challenges and outlining promising directions for advancing hydrogen production via water electrolysis.

08 HYDROGEN↗

DOE OSTI2025

Investigating the Role of Accident Tolerant Cladding on Source Term Reduction for High-Burnup PWRs Using MELCOR

The use of accident tolerant fuel (ATF) cladding can increase coping times during and beyond design basis accidents. While such gains may be incremental, they provide a margin that can potentially be recovered to enable high-burnup (HBU) operation. Realizing such a margin requires demonstrating that the combination of HBU and ATF has not led to an overall increase in source term. This study investigates the influence of cladding technology (Zr-based, Cr-coated Zr, and FeCrAl) and fuel cycle length (18 and 24 months) on radiological dose at the boundary of the exclusion zone for a four-loop pressurized water reactor to investigate whether ATF claddings can provide such benefits. We analyze a recovered large break loss-of-coolant accident scenario to investigate the impact of transient timescale on the benefits of such coping time increases. The simulations have been performed using the MELCOR and MELCOR Accident Consequence Code System codes. For the cases analyzed, increased fuel cycle length did not necessarily increase radionuclide release and hydrogen generation, as these were found to be sensitive to the core power distribution. Similarly, off-site dose consequence is dominated by short-lived radionuclides that tend to saturate earlier in the burnup, so higher burnup operation did not necessarily increase the source term for the phenomena and transients analyzed here. Delays in recovery of the lowpressure safety injection system increase hydrogen production and radionuclide release, especially between 780 s and 1620 s, due to the nonlinear oxidation and core degradation behavior. Results show that Cr-coated Zr enhances safety by delaying heatup and gap release. Here, when uncertainty propagation on oxidation properties is considered, FeCrAl exhibits the lowest overall radionuclide release and off-site dose throughout the spectrum. However, while the considered “base model” performance is superior under delayed injection scenarios, upper-bound cases display hydrogen generation risk comparable to the Zr-based cladding.

Accident Tolerant Fuel↗

DOE OSTI2021

Regional Hybrid Energy Systems Technoeconomic Analysis

The National Renewable Energy Laboratory (NREL) has been working with the Idaho National Laboratory (INL) and Argonne National Laboratory (ANL) to analyze the potential that hybridizing Xcel Energy's two nuclear power plants in Minnesota might have. The hybrid nuclear power plants would maximize sales of electricity when its price is high and reduce electricity sales to maximize hydrogen production when the price of electricity is low. This presentation summarizes the project's approach and status and communicates future direction.

ENERGY PLANNING, POLICY, AND ECONOMY,HYDROGEN↗

DOE OSTI2022

Ligand-coordination effects on the selective hydrogenation of acetylene in single-site Pd-ligand supported catalysts

The selective hydrogenation of acetylene to ethylene is a critical step in the synthesis of polyethylenes. Achieving high conversion to ethylene without over-hydrogenation to ethane is a challenge that requires control of the transition metal site, which we achieve through a ligand-coordinated supported catalyst (LCSC) strategy. Using Pd catalysts coordinated to 1,10-phenanthroline-5,6-dione (PDO) ligands on CeO2 supports, we have discovered that the reaction selectivity depends strongly on the ligand:metal ratio with higher selectivity when more ligand is present in the catalyst. Catalyst structure was examined by extended X-ray absorption fine structure spectroscopy, transmission electron microscopy, and CO adsorption, which indicate single-atom character of the Pd. The ligand:metal ratio is determined by Xray photoelectron spectroscopy measurements and correlated with hydrogenation reactions under steady-state flow conditions to examine trends in hydrogenation activity and selectivity. Those trends can be better understood by density functional theory calculations that indicate hydrogen binding on the ligand to guide reaction selectivity toward the desired ethylene hydrogenation product. Here these results demonstrate the importance of considering the dynamic character of LCSCs and inform the design of future single-site heterogeneous catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2023

Silver-decorated palladium on carbon catalyst for enhanced ammonium formate dehydrogenation

Palladium (Pd)-based catalysts efficiently convert ammonium formate solution to hydrogen at low temperatures (<100 °C), but they tend to deactivate quickly during stability testing. This manuscript presents a systematic investigation into the catalytic properties of Pd–Ag bimetallic catalysts, focusing on their surface compositions and exploring the mechanisms behind the deactivation of Pd/Ag-based catalysts. Here this study reports a carbon-supported Pd–Ag bimetallic nanoparticle (NP) catalyst obtained through a galvanic replacement method, which showed enhanced formate dehydrogenation performance. The best catalyst, Pd 3 Ag 10 /ACA-G (Pd–Ag bimetallic NPs with a 3 : 10 mass ratio loaded on acid-washed activated carbon, prepared by the galvanic replacement method), presents the highest activity with a TOF of 5202 h -1 (~2.6-fold of commercial Pd/C). The enhanced electron density of Pd–Ag bimetallic nanoparticles, coupled with the advantages of a smaller nanoparticle size, and the modulation of hydrogen adsorption energy through the Ag/Pd surface alloy on the Ag/Pd(111) facet, collectively resulted in experimentally higher turnover rates of hydrogen production. The changes on the catalyst surface, including surface Ag fraction decrease, NP size growth, and O-containing species (carboxylate, etc.) adsorption, gradually resulted in catalyst deactivation.

08 HYDROGEN↗

DOE OSTI2024

Unraveling residual trapping for geologic hydrogen storage and production using pore-scale modeling

Not Available

08 HYDROGEN↗

DOE OSTI2020

All-solid-state Z-scheme BiVO 4 –Bi 6 O 6 (OH) 3 (NO 3 ) 3 heterostructure with prolonging electron-hole lifetime for enhanced photocatalytic hydrogen and oxygen evolution

As a visible-light response photocatalyst, BiVO 4 is widely used in photocatalytic oxygen evolution. In this study, a novel BiVO 4 –Bi 6 O 6 (OH) 3 (NO 3 ) 3 (BBN) heterostructure fabricates via a simple one-pot hydrothermal approach is certified to effectively restrain the recombination of carriers by efficient spatial charge separation. By employing BBN as a reductive-function photocatalyst, a solid-state Z-scheme is constructed to improve the photo-redox capacity of BiVO 4 and hydrogen production is realized in the BiVO 4 –BBN heterostructure for the first time. Furthermore, the solid-state Z-scheme introduced in the BiVO 4 –BBN ensures the photoexcited carriers with the powerful redox capacity to participate in the photocatalytic reaction.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Ultrathin platinum nanowire based electrodes for high-efficiency hydrogen generation in practical electrolyzer cells

Significant reduction of noble metal catalyst loading and simplification of electrode fabrication are urgently needed in order to lower the cost of proton exchange membrane electrolyzer cells (PEMECs) for large-scale hydrogen production. Herein, we report an integrated electrode design comprising in-situ grown platinum nanowires (PtNW) on ultrathin titanium liquid/gas diffusion layers (LGDLs) via a cost-effective and green chemical synthesis approach. The ultrathin integrated PtNW electrodes showed a low cell voltage of 1.643 V and high efficiency of 90.08% at 1000 mA cm -2 using about 15 times lower catalyst loadings than a conventional catalyst-coated membrane in PEMEC tests. Ex-situ electrochemical characterizations and microscale visualizations further reveal that PtNW electrodes display highly efficient hydrogen evolution reactions and excellent electrode durability due to high active surface area, favorable bubble detachment, and structural stability. This work provides new insights into catalyst layer design and facile ultrathin electrode fabrication for more compact and low-cost PEM electrolyzers, fuel cells and other systems.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2021

Current research in low temperature proton exchange membrane-based electrolysis and a necessary shift in focus

While hydrogen has limited use in energy markets today, significant growth is possible in grid storage and as an energy carrier in other sectors. Along with lower electricity prices, further hydrogen cost reduction can enable electrochemical water splitting, particularly as the use of intermittent, renewable power sources increases and the quantity and duration of storage requirements limit electrical storage options. With the improved viability of large-scale hydrogen production, research in low temperature electrolysis has dramatically increased. The overwhelming majority of research efforts within proton exchange membrane-based systems has focused on catalyst development, although a smaller set have developed transport layers as well. As proton exchange membrane-based electrolysis shifts into higher technology readiness levels, however, there is a growing need for work optimizing materials integration, developing component-specific and device-level accelerated stress tests, and addressing manufacturing considerations. These areas directly impact electrolyzer performance, durability, and cost, and are critical to advancing hydrogen’s value and electrochemical water splitting.

08 HYDROGEN↗

DOE OSTI2025

Application of a temporal multiscale method for efficient simulation of degradation in PEM Water Electrolysis under dynamic operating conditions

Hydrogen is emerging as a vital energy carrier, driven by the need to reduce carbon emissions. Proton Electrolyte Membrane Water Electrolysis (PEMWE) enables hydrogen production under fluctuating renewable power conditions but requires improved understanding and stability of the anode catalyst layer under dynamic operating conditions, especially with low noble metal loadings. Long-term degradation experiments are both time-consuming and costly; therefore, a systematic, model-aided approach is essential. In the present work, a temporal multiscale method is applied to reduce the computational effort of simulating long-term degradation processes in PEMWE, with an exemplary focus on catalyst dissolution. A mechanistic model incorporating the oxygen evolution reaction, catalyst dissolution, and hydrogen permeation from the cathode to the anode was hypothesized and implemented. In this way, the local periodicity of transport and reaction processes in dynamic PEMWE operation, which influence the gradual degradation of the catalyst layer, is captured. The temporal multiscale method significantly reduces the computational effort of simulation, decreasing processing time from hours to mere minutes. This efficiency gain is attributed to the limited evolution of Slow-Scale variables during each period of time P of the Fast-Scale variables. Consequently, simulation is required only until local periodicity is achieved within each Slow-Scale time step. Hence, the fully resolved dynamic problem is decoupled into these two scales, employing a heterogeneous multiscale technique. The developed approach effectively accelerates parameter estimation and predictive simulations, supporting systematic modeling of PEMWE degradation under dynamic conditions.

08 HYDROGEN↗

DOE OSTI2024

Potential Integration Between Residual Biogenic Process Resources and Green Hydrogen [Slides]

This presentation highlights previously published analysis on the use of off-gases from biomass pyrolysis processes towards energy utilities. The potential for use of pyrolysis off-gases in existing steam reformers for green hydrogen production is assessed. Impacts on various operations within a steam reforming system (with natural gas as the primary base feed) from the introduction of pyrolysis off-gases in various proportions are quantified to assess the feasibility of reusing existing industrial facilities with renewably sourced gases.

09 BIOMASS FUELS↗