Savannah River National Laboratory Research Articles

Spectroscopic analysis of Pu-bearing compounds in double-walled cells

Spectroscopic analysis of radiological materials has been historically limited to radiological labs with older or less advanced scientific instrumentation. The development of double-walled cells (DWCs) at the Savannah River National Laboratory (SRNL) has enabled Pu-bearing compounds to be removed from radiological laboratories and studied in our radiologically clean spectroscopy laboratory with state-of-the-art instrumentation. In this manuscript, we discuss the contributions of DWCs that have allowed the application of Raman spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), diffuse reflectance spectroscopy (DRS) in the shortwave infrared, and gamma spectroscopy at SRNL. Significant advances have been made in the understanding of the thermal decomposition of Pu(III) and Pu(IV) oxalates, alpha-induced damage to the PuO2 crystal lattice, and the effect of calcination temperatures on the quality of PuO2. These techniques have enabled methods to conduct PuO2 age dating since last calcination and estimate the calcination temperature with Raman spectroscopy and DRS. Additional spectroscopic information measured with DRIFTS has enabled the observation of the evolution of carbon species with calcination temperature, while gamma spectroscopy provides information on age dating since last purification.

Real-time infrared spectroscopy coupled with blind source separation for nuclear waste process monitoring

On-line infrared absorbance spectroscopy enables rapid measurement of solution-phase molecular species. Many spectra-to-concentration models exist for spectral data, with some models able to handle overlapping spectral bands and nonlinearities. However, model accuracy is limited by the quality of training data used in model fitting. The process spectra of nuclear waste simulants at the Savannah River Site display incongruity between training and process spectra; the glycolate spectral signature in the training data does not match the glycolate signature in Savannah River National Laboratory process data. A novel blind source separation algorithm is proposed that preprocesses spectral data so that process spectra more closely resemble training spectra, thereby improving model quantification accuracy when unexpected sources of variation appear in process spectra. The novel blind source separation preprocessing algorithm is shown to improve nitrate quantification from an R2 of 0.934 to 0.988 and from 0.267 to 0.978 in two instances analyzing nuclear waste simulants from the Slurry Receipt Adjustment Tank and Slurry Mix Evaporator cycle at the Savannah River Site.

Heuristic techniques for maximum likelihood localization of radioactive sources via a sensor network

Maximum likelihood estimation (MLE) is an effective method for localizing radioactive sources in a given area. However, it requires an exhaustive search for parameter estimation, which is time-consuming. In this study, heuristic techniques were employed to search for radiation source parameters that provide the maximum likelihood by using a network of sensors. Hence, the time consumption of MLE would be effectively reduced. First, the radiation source was detected using the k-sigma method. Subsequently, the MLE was applied for parameter estimation using the readings and positions of the detectors that have detected the radiation source. A comparative study was performed in which the estimation accuracy and time consumption of the MLE were evaluated for traditional methods and heuristic techniques. The traditional MLE was performed via a grid search method using fixed and multiple resolutions. Additionally, four commonly used heuristic algorithms were applied: the firefly algorithm (FFA), particle swarm optimization (PSO), ant colony optimization (ACO), and artificial bee colony (ABC). The experiment was conducted using real data collected by the Low Scatter Irradiator facility at the Savannah River National Laboratory as part of the Intelligent Radiation Sensing System program. The comparative study showed that the estimation time was 3.27 s using fixed resolution MLE and 0.59 s using multi-resolution MLE. The time consumption for the heuristic-based MLE was 0.75, 0.03, 0.02, and 0.059 s for FFA, PSO, ACO, and ABC, respectively. The location estimation error was approximately 0.4 m using either the grid search-based MLE or the heuristic-based MLE. Hence, heuristic-based MLE can provide comparable estimation accuracy through a less time-consuming process than traditional MLE.

The Highly Operational Team (HOT) toward f-Block Materials.

This invited Team Profile was created by the scientists in the Highly Operational Team (HOT) led by the Shustova group from the University of South Carolina (USA). HOT researchers are located at four universities (the University of South Carolina, Clemson University, the University of Florida, and Chulalongkorn University) and one national laboratory (Savannah River National Laboratory) from two different countries, USA and Thailand. The team recently published an article using the synergy among the HOT participants to reveal the synthetic pathways toward preparation of transuranic heterometallic extended metal-organic materials, providing mechanistic details for their formation, and establishing a structure-property relationship: "f-block MOFs: A Pathway to Heterometallic Transuranics", K. C. Park, P. Kittikhunnatham, J. Lim, G. C. Thaggard, Y. Liu, C. R. Martin, G. A. Leith, D. J. Toler, A. T. Ta, N. Birkner, I. Lehman-Andino, A. Hernandez-Jimenez, G. Morrison, J. W. Amoroso, H.-C. zur Loye, D. P. DiPrete, M. D. Smith, K. S. Brinkman, S. R. Phillpot, N. B. Shustova, Angew. Chem. Int. Ed. Engl. 2023, 62, e202216349.

The Highly Operational Team (HOT) toward f‐Block Materials

AbstractThis invited Team Profile was created by the scientists in the Highly Operational Team (HOT) led by the Shustova group from the University of South Carolina (USA). HOT researchers are located at four universities (the University of South Carolina, Clemson University, the University of Florida, and Chulalongkorn University) and one national laboratory (Savannah River National Laboratory) from two different countries, USA and Thailand. The team recently published an article using the synergy among the HOT participants to reveal the synthetic pathways toward preparation of transuranic heterometallic extended metal–organic materials, providing mechanistic details for their formation, and establishing a structure–property relationship: “f‐block MOFs: A Pathway to Heterometallic Transuranics”, K. C. Park, P. Kittikhunnatham, J. Lim, G. C. Thaggard, Y. Liu, C. R. Martin, G. A. Leith, D. J. Toler, A. T. Ta, N. Birkner, I. Lehman‐Andino, A. Hernandez‐Jimenez, G. Morrison, J. W. Amoroso, H.‐C. zur Loye, D. P. DiPrete, M. D. Smith, K. S. Brinkman, S. R. Phillpot, N. B. Shustova, Angew. Chem. Int. Ed. Engl. 2023, 62, e202216349.

C&EN talks with Christopher J. Bannochie, nuclear chemist at Savannah River National Laboratory

When Christopher J. Bannochie isn’t traveling the world, he works at the Savannah River National Laboratory (SRNL) and is a councilor for the American Chemical Society Savannah River Section. As a nuclear chemist, he has identified various species of mercury in radioactive waste. As an advocate for the LGBTQ+ community, he serves on the board of directors for the Open Chemistry Collaborative in Diversity Equity at Johns Hopkins University, represents the professional society Out to Innovate on the ACS Diversity, Equity, Inclusion, and Respect Experts Panel, and is the management sponsor for the Gay, Lesbian, or Bisexual Employees and Allies Association at the SRNL. Kieran Tarazona Carrillo spoke with Bannochie about his experience in chemistry, his advice for LGBTQ+ people, and the places he has traveled to. This interview has been edited for length and clarity. Can you tell me a bit about your current research and the most interesting

C&EN talks with Christopher J. Bannochie, nuclear chemist at Savannah River National Laboratory

C&EN talks with Christopher J. Bannochie, nuclear chemist at Savannah River National Laboratory

Ultra-low-level measurements of airborne fission products from the Fukushima Daiichi reactor accident using high volume collection systems at Savannah River National Laboratory

Ultra-low-level measurements of radionuclides in air have been conducted at the Savannah River National Laboratory (SRNL) to determine the atmospheric concentration of fission products released following the Fukushima Daiichi reactor accident on March 11, 2011. Air filter samples were acquired from two high-volume collection systems (a traditional filter-based system and an electrostatic precipitator-based system) to monitor airborne radionuclide concentrations in the period covering from 2 weeks to 3 years after the disaster. The world-wide spread of low-level concentrations of airborne fission products from the Fukushima event provided a unique opportunity to demonstrate SRNL's electrostatic particle collection technology and other improvements in environmental monitoring developed at the Savannah River Site (SRS). Detecting and analyzing the release allowed a comprehensive test of SRS systems for monitoring environmental radioactivity. Gamma-ray-emitting fission products (131,132I, 134,136,137Cs, and 129,132Te) and cosmogenic isotopes (7Be and 22Na) in air were detected and quantified by high-resolution gamma-ray spectroscopy at concentrations as low as 0.07 μBq per standard cubic meter (SCM) (50 mBq total 137Cs), while plutonium content was quantified by thermal ionization mass spectrometry (TIMS) at concentrations as low as 6.5 × 10−21 g/SCM (3.0 fg 239+240Pu). Isotope concentrations measured at SRNL from gamma-ray spectroscopy were compared to independent measurements from Chapel Hill, NC, located approximately 370 km (230 mi) NE of SRNL. Meteorological modeling was also used to predict radionuclide transport from the location of release to both measurement locations.

Catalytic Effects of Silver in Iodine Reactors for Dissolved Used Nuclear Fuel

The dissolution of used nuclear fuel generates a variety of off-gasses including flammable hydrogen and other species that are a concern for environmental release. The H-Canyon facility at the Savannah River Site is currently dissolving aluminum-clad research reactor fuel from material test reactors and the High Flux Isotope Reactor (HFIR) using a mercury-catalyzed nitric acid flowsheet. Savannah River National Laboratory recently developed and deployed a Raman spectrometer to monitor the off-gas stream from the dissolution process. Results from these measurements indicated a lack of the expected hydrogen, nitrous oxide, and nitric oxide in the off-gas stream. It was proposed that the silver on the silver nitrate–coated berl saddles present in the reactors for iodine capture were acting as a catalytic hydrogen recombiner. Nitric oxide is readily oxidized to nitrogen dioxide under normal conditions, but it was unclear what happened to the nitrous oxide. A laboratory-scale iodine reactor was assembled and filled with silver nitrate–coated berl saddles to help ascertain the fate of nitrous oxide and hydrogen. Testing with this laboratory-scale reactor observed the recombination of hydrogen when a simulated dissolver off-gas was passed through the reactor containing silver nitrate–coated berl saddles at the approximate temperatures seen in H-Canyon. However, the nitrous oxide concentration was unchanged, suggesting a more complex process occurring within the off-gas stream before it reaches the iodine reactors at H-Canyon.

Alloying of Pu-Al with Stainless Steel for Material Disposition

The Savannah River National Laboratory has evaluated several options for the disposition of stainless steel (SS)–clad plutonium metal alloy. One of the technologies under consideration is alloying of the material with SS. The resulting SS-Pu alloy would be a nonproliferable waste form consisting of a secondary Pu composition region microencapsulated in the refractory SS. Two 8-kg ingots were made at SS-1.8Zr-0.4Pu alloys (in weight percent); 8 kg was determined in a previous study to be the maximum mass of SS ingot at the maximum target Pu loading of 350 g that would result in a SS-4.4Pu alloy (in weight percent). Two smaller 500-g ingots were also produced at SS-1.6Zr-1.4Pu and SS-1.4Pu (in weight percent). The alloying of 500-g ingots at a higher Pu concentration than in the 8-kg ingots was evaluated, and the necessity of adding Zr metal to incorporate the Pu and control Pu oxidation was evaluated. Zirconium addition was found to be unnecessary to incorporate the Pu and control Pu oxidation. Drill turnings were collected from the large and small ingots, and metallographic samples were directly cut from the small ingots. Both were analyzed to validate the structure and composition region formation. Chemical analyses of turnings proved that the Pu was dispersed within the SS ingots.

Alloying of U-Al-SS as a Simulant for Pu-Al-SS Alloying

The Savannah River National Laboratory evaluated several options for disposition of stainless steel (SS)–clad plutonium metal, particularly Pu-10.6 at. % Al (Pu- 1.3 wt% Al) alloy fuel. One technology considered was alloying fuel with SS. The goal of the alloying would be to make a SS-Pu alloy that was a nonproliferable waste form with secondary Pu-rich microencapsulated regions distributed throughout the refractory SS. The microencapsulation of the Pu regions should therefore allow the waste form to meet the requirements for a low attractiveness waste as defined by the U.S. Department of Energy. Plutonium-bearing alloys at these levels could potentially be suitable for disposal at a waste isolation pilot plant. Four metal ingots were successfully fabricated using U and Al as a surrogate for Pu-Al. The U was distributed and microencapsulated by the alloy matrix, thereby setting the stage for subsequent tests using SS-clad fuel elements containing Pu-10.6Al.

(Invited) H-Mat Materials Compatibility Consortium

The H-Mat consortium (https://h-mat.org) was launched by the U.S. Department of Energy’s Hydrogen and Fuel Cell Technologies Office within the Office of Energy Efficiency and Renewable Energy to address R&D challenges regarding materials compatibility with hydrogen. H-Mat is led by Sandia National Laboratories and Pacific Northwest National Laboratory, and includes participation from Savannah River National Laboratory, Oak Ridge National laboratory, and Argonne National Laboratory, along with partners across industry and academia collaborating on joint R&D projects and coordinated R&D efforts. Key R&D thrusts include: 1) addressing the compatibility of pipeline materials with blends of hydrogen and natural gas, as part of DOE’s HyBlend project, 2) enhancing the life of polymers (e.g. seal materials) in high-pressure hydrogen service, 3) improving fracture resistance of low-cost steels in hydrogen service to enable their use in high-pressure hydrogen component, 4) assessing the rate at which cracks initiate in metals in hydrogen environments, to inform longer component service lives, and 5) assessing performance of metals in cryogenic hydrogen, at temperatures as low as 20K. This presentation will describe their ongoing R&D activities and prior accomplishments that have informed design and development of hydrogen components and associated codes and standards.

Large Transformer Criticality, Threats, and Opportunities

Large power transformers (LPTs) represent a critical “tent‐pole” in national electric power grid, and national resiliency. They are essential to both the generation and transmission sectors of our electric power grid. They are known to be targets in adversaries' plans to debilitate our critical infrastructures. Their high cost and supply chain issues involving months to years of replacement times dictate the importance of survivability assurance. Transformer vulnerability and protection are addressed for physical attacks, cyber, and electromagnetic effects, including solar weather geomagnetic disturbance (GMD) and high altitude burst nuclear electromagnetic pulse (EMP) effects. Programs have been underway to improve transformer and transformer substation cyber and physical resiliency. Similar programs are lagging for electromagnetic threats. Transformer vulnerability to EMP remains a subject of conjecture since no large power transformer has undergone threat‐level EMP testing. Prevalent claims that LPTs are immune to EMP are premature.The Savannah River National Laboratory has developed a test program and designed a test bed to complete testing on LPTs including physical set‐up, injection sources, and measurement equipment to enable transformer testing under real load conditions without harming the larger power grid. The SNRL test bed will enable tests to determine both transformer vulnerability thresholds and the effectiveness of protection devices. A concerted national effort is needed to determine LPT vulnerabilities and to expeditiously develop and certify effective EMP and GMD protection approaches.

Pressurization Analysis for Heating of a Screw Top Utility Can Loaded With Plutonium Oxide Powder by a 1273 K Fire

AbstractThe documented safety analysis for the Savannah River National Laboratory (SRNL) evaluates the consequences of a postulated 1273 K fire in a glovebox. The radiological dose consequences for a pressurized release of plutonium oxide powder during such a fire depend on the maximum pressure that is attained inside the oxide storage containers. The oxide storage configuration selected for analysis is can/bag/can, comprised of oxide powder inside an 8.38 × 10−6 m3 stainless steel B vial inside 0.006 kg of polyethylene bagging inside a one-quart screw top utility can of the type commonly used to package solvents or rubber cements. To enable evaluation of the dose consequences, temperature and pressure transients have been calculated for exposure of a typical set of storage containers to the fire. The pressurization analysis credits venting to and from the B vial but does not credit venting or leakage from the can. Due to the low rate of venting from the B vial into the can gas space, the can pressure is nearly independent of the B vial pressure. Calculated maximum pressures are compared to the utility can burst pressure. In lieu of a structural analysis of the utility cans, burst pressures and leakage rates were measured using compressed nitrogen gas. The measured gauge burst pressure was 0.250 ± 0.043 MPa. The measured burst pressures are lower than the calculated maximum pressure due to fire exposure, indicating that the utility cans could burst during exposure to a 1273 K fire.

Scaling Trivalent Actinide and Lanthanide Recovery by Diglycolamide Resin from Savannah River Site’s Mark-18A Targets

The Savannah River National Laboratory is implementing a separation flowsheet to recover rare isotopes and transplutonium elements from irradiated 242Pu targets known as Mark-18A targets. The Mark-...

Failure Analysis of Gas Spray Atomization Crucible Materials

An attempted induction melt for gas spray atomization of a Pd alloy at Savannah River National Laboratory experienced a series of faulty thermocouple readings leading to failure of multiple alumina ceramic components and the loss of the metal charge. The spherical powders are used in the research and development efforts for hydrogen storage applications. The failure of the thermocouples led to high operating temperatures exceeding the expected operating temperatures. Estimated temperatures of the liquid metal were established by the comparison of the radio frequency power output and multiple temperature readings and determined to have exceeded the functional temperature range of the alumina components. Failure analyses of the event included characterization of the components using visual observation and X-ray computed tomography of the frozen ingot.

Seeking frequent episodes in baseline data of In-Situ Decommissioning (ISD) Sensor Network Test Bed with temporal data mining tools

Savannah River National Laboratory (SRNL) has established an In-Situ Decommissioning (ISD) Sensor Network Test Bed—a unique, small scale, and configurable environment— for the assessment of prospective sensors on actual ISD system at minimal cost. The temporal data mining (TDM) technique can be employed to process the extensive data collected by the ISD sensors well because these data are time-specific, age-specific, and development stage-specific. This paper analyzed the baseline data collected by ISD Sensor Network Test Bed in recent years with the assistant of TDM algorithms to work out frequency episodes in the event stream. The results have confirmed that TDM techniques are effective tools to validate ISD performance, and the frequent episodes found in the data stream not only showed the daily cycle of the sensor responses, but also established the response sequences of different types of sensors, which was verified by the actual experimental setup. Some abnormal patterns may have the potential for prediction of system failures.

Tritium Aging Effects on Fracture Toughness of Stainless Steel Weldments

The long-term embrittlement effects of tritium and decay helium on the structural properties of stainless steels have been studied for years at Savannah River National Laboratory (Savannah River) to provide required data for establishing safe operating conditions and the lifetimes of the pressure vessels used to contain tritium gas. In this study, the fracture toughness properties of the longest-aged tritium-precharged stainless steel base metals and weldments tested at Savannah River were measured and compared to earlier results. The fracture toughness values were the lowest recorded here for tritium-exposed stainless steel. As-forged and as-welded specimens were thermally precharged with tritium gas at 34.5 MPa and 623 K, then aged for up to 17 years to build in decay helium prior to testing. American Society for Testing and Materials J-integral fracture mechanics analyses, transmission electron microscopy (TEM), and small-angle neutron scattering (SANS) examinations were conducted to characterize the effects of tritium and its radioactive decay product 3He. Results show that the fracture toughness values were reduced to less than 2% to 4% of the as-forged values for specimens with more than 1300 atomic parts per million helium from tritium decay. The trend of decreasing fracture toughness values with increasing helium content was consistent with earlier observations, and the data show that Type 304L stainless steel is more resistant to tritium-induced cracking than Type 21-6-9 stainless steel at similar decay helium levels. The fracture toughness properties of long-aged weldments were also affected, but the reductions were not as severe over time because the weldments did not retain as much tritium as did the base metals. TEM observations were used to characterize the effects of decay helium bubbles on the deformation substructures, but nanometer-sized helium bubbles were not easily resolved because of high dislocation densities within the forged microstructures. SANS results are presented that suggest the technique can provide information on decay helium bubble size, spacing, and distribution in these steels.

GENOMIC, METABOLIC, AND PHYSIOLOGICAL CHARACTERIZATION OF SERRATIA SP. SRS‐8‐S‐2018 ISOLATED FROM HEAVY METAL CONTAMINANT SOILS OF THE SAVANNAH RIVER SITE, USA

Serratia sp. SRS‐8‐S‐2018 was isolated from mercury (Hg) contaminated soil samples collected from the Savannah River Site (SRS). SRS is located on the northeast bank of the Savannah River (South Carolina, USA). Strain SRS‐8‐S‐2018 grew in various levels of Hg ranging from 5–30 μg/ml. To understand metabolic and physiological features of strain SRS‐8‐S‐2018, Biolog Ecoplate assays were performed under different Hg concentrations, which demonstrated that strain SRS‐8‐S‐2018 actively metabolized carbohydrates, amino acids, carboxy acids, polymers, and esters; however, the physiological response was significantly hampered at increasing concentrations of Hg from 1–5 μg/ml. a draft genome sequence of strain SRS‐8‐S‐2018 was conducted, which revealed a genomic size of 5,323 630 bp and an average G+C content of 59.48 %. The genome consisted of 159 contigs, N50 of 101301 bases and L50 of 17, a coding sequence of 5,261 proteins (CDS), 55 genes for tRNA, and three genes for rRNA, An in‐depth, genome‐wide comparison between strain SRS‐8‐S‐2018 and its four closest taxonomic relatives revealed 1159 distinct genes, with multiple functions including antibiotic resistance and heavy metal resistance respectively. Further annotations revealed that strain SRS‐8‐S‐2018 consisted of 585 subsystems with the following top six categories belonging to amino acid metabolism 428 genes; carbohydrate metabolism 391 genes; vitamin and cofactor metabolism 197 genes; protein metabolism 116 genes; membrane transport 136 genes and fatty acids and lipids 136 genes respectively. Several gene homologs previously shown to be involved in the resistance against heavy metals/radionuclides, including the cobalt‐zinc‐cadmium efflux system, membrane transporters, and antimicrobial extrusion proteins, were also identified, which likely facilitates the survival of strain SRS‐8‐S‐2018 in an Hg‐contaminated soil habitat. Additionally, several genes homologous for antibiotic resistance were also identified in strain SRS‐8‐S‐2018. The relationship between heavy metal contamination and antibiotic resistance was performed using the Biolog phenotype microarray assay which confirmed the widespread resistance of strain SRS‐8‐S‐2018 to a variety of different antibiotics. Specifically, 48 different types of antibiotics were screened which unequivocally showed resistance of strain SRS‐8‐S‐2018 to 81.25% of the tested antibiotics. Overall, this study indicates that heavy metal contaminants not only pose ecological and public health toxicity risks but also stress the environmental microbiomes, which respond by acquiring metal resistant genes (MRGs) via horizontal gene transfer (HGT) or genomic mutations for survival. The metal resistant genes can possess antimicrobial activities or facilitate the recruitment of additional antimicrobial‐resistant genes (ARGs), thus exacerbating the environmental toxicity issuesSupport or Funding InformationThis work was supported by the Department of Energy (DOE) Minority Serving Institution Partnership Program (MSIPP) managed by the Savannah River National Laboratory under SRNS contract #DE‐AC09‐08SR22470 [Task Order Agreements (TOAs) 0000403081 and 0000403082].Conflict 0

Integrated Electrochemical-Thermal System for High Efficiency and Low Cost Hydrogen Compression

Three approaches to transport and delivery hydrogen at large scale have been identified by the US Department of Energy [1]. Each of the approaches requires the presence of high-pressure hydrogen compression systems. Currently DOE set its fueling station pressure targets at approximately 875 bar with flow rates up to 100 kg/h [1]. Among the other targets for hydrogen compression systems, DOE identified the uninstalled cost target for the FY 2020 at 275,000 $, the energy requirement at 1.6 kWh/kg, availability equal to 85% and annual maintenance cost equal to 4% of the uninstalled cost[1] [1]. The current mechanical compressors cannot achieve the DOE targets and they have several additional drawbacks working at the specified operating conditions, especially in terms of reliability, efficiency and investment and lifetime costs. Valid alternative processes are represented by electrochemical compression (EC) systems and thermal compression systems, exploiting the properties of suitable hydrogen absorption materials. A two-stage hybrid compressor system is proposed, with a first stage (lower pressure) EC, coupled in series with a second stage (higher pressure) metal hydride (MH) thermal compression system. The EC operates at compression ratios on the order of 10-20, reaching pressures of about 100-200 bar. Molecular hydrogen is oxidized at the anode producing protons and electrons. They are driven through the proton exchange membrane and combine with electrons at the cathode to deliver high pressure hydrogen. The outlet pressure is maintained at relatively low values (≤ 100-200 bar) in order to avoid hydrogen back diffusion. The second stage of the system, operating at higher pressures, is comprised of a thermal compression system, based on MH materials. Such compounds absorb hydrogen in an exothermic chemical reaction and release the absorbed hydrogen in the reverse endothermic chemical reaction. Their equilibrium pressure is a direct exponential function of the operating temperature. Therefore, providing high temperature thermal power during the desorption process, the hydrogen pressure can be increased without the use of electricity. The paper presents the results obtained from a project funded by DOE, involving Greenway Energy, Savannah River National Laboratory and Sustainable Innovation. An electrochemical system, using Nafion-117® membrane, was successfully tested at high operating temperatures (≈ 150 °C) and pressures up to 100 bar, representing the baseline configuration for the first stage of the compression system. The second stage of the compressor, based on metal hydride systems, was tested using a commercially available Ti1.1CrMn material as the baseline alloy, achieving pressures on the order of 500-600 bar at temperatures on the order of 150 °C. A novel heat transfer system was also identified and designed to recover the available waste heat from the electrochemical system and drive the thermal compression process in the MH system. Overall system efficiency and costs were also assessed, with the results presented and discussed.