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DOE OSTI2018

Numerical Modeling of Ion-Optical Systems for Extraction of a Beam of Negative Hydrogen Ions and Its Acceleration and Matching with a Radio-Frequency Quadrupole Accelerator

A source of negative hydrogen ions is constructed at the Institute for High Energy Physics in order to raise the intensity of the U-70 accelerator complex using multiturn charge-exchange injection. The 3D ion-optical IBSimu simulation package was used to model and optimize the system for extraction of an ion beam from plasma, its acceleration to 100 keV, and matching with a radio-frequency quadrupole (RFQ) accelerator. The system of extraction of an ion beam with a current of 50 mA and electron-flow suppression was modeled. The magnetic transport channels with two solenoids and six quadrupole lenses were compared. The end goals of analysis of the matching channel were to obtain the needed Twiss parameters and to minimize the emittance growth at the RFQ input.

43 PARTICLE ACCELERATORS↗

DOE OSTI2014

Vacuum Permeator Analysis for Extraction of Tritium from DCLL Blankets

It is envisioned that tritium will be extracted from DCLL blankets using a vacuum permeator. We derive here an analytical solution for the extraction efficiency of a permeator tube, which is a function of only two dimensionless numbers: one that indicates whether radial transport is limited in the PbLi or in the solid membrane, and another that is the ratio of axial and radial transport times in the PbLi. The permeator efficiency is maximized by decreasing the velocity and tube diameter, and increasing the tube length. This is true regardless of the mass transport correlation used; we review several here and find that they differ little, and the choice of correlation is not a source of significant uncertainty here. The PbLi solubility, on the other hand, is a large source of uncertainty, and we identify upper and lower bounds from the literature data. Under the most optimistic assumptions, we find that a ferritic steel permeator operating at 550 °C will need to be at least an order of magnitude larger in volume than previous conceptual designs using niobium and operating at higher temperatures.

DCLL↗

DOE OSTI2016

In Situ Visualization and Production of Extract Databases

Simulations running at high concurrency on HPC systems generate large volumes of data that are impractical to write to disk due to time and storage constraints. Applications often adapt by saving data infrequently, resulting in datasets with poor temporal resolution. This can make datasets difficult to interpret during post hoc visualization and analysis, or worse, it can lead to lost science. In Situ visualization and analysis can enable efficient production of small data products such as rendered images or surface extracts that consist of polygonal geometry plus fields. These data products are far smaller than their source data and can be processed much more economically in a traditional post hoc workflow using far fewer computational resources. We used the SENSEI and Libsim in situ infrastructures to implement rendering workflow and surface data extraction workflows in the AVF-LESLIE combustion code. Finally, these workflows were then demonstrated at high levels of concurrency and showed significant data reductions and limited impact on the simulation runtime.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2016

Magnetic Nanofluid Rare Earth Element Extraction Process Report, Techno Economic Analysis, and Results for Geothermal Fluids

This GDR submission is an interim technical report and raw data files from the first year of testing on functionalized nanoparticles for rare earth element extraction from geothermal fluids. The report contains Rare Earth Element uptake results (percent removal, mg Rare Earth Element/gram of sorbent, distribution coefficient) for the elements of Neodymium, Europium, Yttrium, Dysprosium, and Cesium. A detailed techno economic analysis is also presented in the report for a scaled up geothermal rare earth element extraction process. All rare earth element uptake testing was done on simulated geothermal brines with one rare earth element in each brine. The rare earth element uptake testing was conducted at room temperature.

15 GEOTHERMAL ENERGY↗

DOE OSTI2011

RESULTS OF ROUTINE STRIP EFFLUENT HOLD TANK AND DECONTAMINATED SALT SOLUTION HOLD TANK SAMPLES FROM MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT DURING MACROBATCH 3 OPERATIONS

Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the 'microbatches' of Integrated Salt Disposition Project (ISDP) Salt Batch ('Macrobatch') 3 have been analyzed for {sup 238}Pu, {sup 90}Sr, {sup 137}Cs, and by Inductively Coupled Plasma Emission Spectroscopy (ICPES). The results indicate good decontamination performance within process design expectations. While the data set is sparse, the results of this set and the previous set of results for Macrobatch 3 samples indicate consistent operations. However, the Decontamination Factors for plutonium and strontium removal have declined in Macrobatch 3, compared to Macrobatch 2. This may be due to the differences in the Pu concentration or the bulk chemical concentrations in the feed material. SRNL is considering the possible reasons for this decline. The DSSHT samples show continued presence of titanium, likely from leaching of the monosodium titanate in ARP. During operation of the ISDP, quantities of salt waste are processed through the Actinide Removal Process (ARP) and MCU in batches of {approx}3800 gallons. Monosodium titanate (MST) is used in ARP to adsorb actinides and strontium from the salt waste and the waste slurry is then filtered prior to sending the clarified salt solution to MCU. The MCU uses solvent extraction technology to extract cesium from salt waste and concentrate cesium in an acidic aqueous stream (Strip Effluent - SE), leaving a decontaminated caustic salt aqueous stream (Decontaminated Salt Solution - DSS). Sampling occurs in the Decontaminated Salt Solution Hold Tank (DSSHT) and Strip Effluent Hold Tank (SEHT) in the MCU process. The MCU sample plan requires that batches be sampled and analyzed for plutonium and strontium content by Savannah River National Lab (SRNL) to determine MST effectiveness. The cesium measurement is used to monitor cesium removal effectiveness and the inductively coupled plasma emission spectroscopy (ICPES) is used to monitor inorganic carryover.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2011

RESULTS FROM ANALYSIS OF THE FIRST AND SECOND STRIP EFFLUENT COALESCER ELEMENTS FROM RADIOACTIVE OPERATIONS OF THE MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT

The coalescer elements for the Strip Effluent (SE) acid within the Modular Caustic-Side Solvent Extraction Unit (MCU) experienced elevated differential pressure drop during radioactive operations. Following the end of operations for the first Macrobatch campaign and soon after start of the second Macrobatch campaign, personnel removed the coalescer media and provided to Savannah River National Laboratory (SRNL) for diagnostic investigation of the causes of reduced flow. This report summarizes those studies. Two Strip Effluent (SE) coalescers were delivered to the Savannah River National Laboratory (SRNL). One was removed from the Modular Caustic-Side Solvent Extraction Unit (MCU) between processing of Macrobatch 1 and 2 (coalescer 'Alpha'), and the second was removed from MCU after processing of {approx}24,000 gallons of salt solution (coalescer 'Beta'). Both coalescers underwent the same general strip acid flush program to reduce the dose and were delivered to SRNL for analysis of potential occluding solids. Analysis of Coalescer Alpha indicates the presence of aluminum hydroxide solids and aluminosilicate solids, while analysis of Coalescer Beta indicates the presence of aluminum hydroxide solids, but no aluminosilicates. Leaching studies on sections of both coalescers were performed. The results indicate that the coalescers had different amounts of solids present on them at the time of removal. Finally, samples of free liquids retrieved from both coalescers indicate no excessive amounts of CSSX solvent present. Given the strip acid flushing that occurred in the SE coalescers, the solids we detected on the coalescers are probably indicative of a larger quantity of these solids present before the strip acid flushing. Under this scenario, the excessive pressure drops are due to the solids and not from organic fouling.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2011

Non-Ideal Behavior in Solvent Extraction

This report presents a summary of the work performed to meet FCR&D level 3 milestone M31SW050801, 'Complete the year-end report summarizing FY11 experimental and modeling activities.' This work was carried out under the auspices of the Non-Ideality in Solvent Extraction Systems FCR&D work package. The report summarizes our initial considerations of potential influences that non-ideal chemistry may impose on computational prediction of outcomes in solvent extraction systems. The report is packaged into three separate test cases where a robustness of the prediction by SXFIT program is under scrutiny. The computational exercises presented here emphasize the importance of accurate representation of both an aqueous and organic mixtures when modeling liquid-liquid distribution systems. Case No.1 demonstrates that non-ideal behavior of HDEHP in aliphatic diluents, such as n-dodecane, interferes with the computation. Cases No.2 and No.3 focus on the chemical complexity of aqueous electrolyte mixtures. Both exercises stress the need for an improved thermodynamic model of an aqueous environment present in the europium distribution experiments. Our efforts for year 2 of this project will focus on the improvements of aqueous and non-aqueous solution models using fundamental physical properties of mixtures acquired experimentally in our laboratories.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

DOE OSTI2013

Recommended Guanidine Suppressor for the Next-Generation Caustic-Side Solvent Extraction Process

The guanidine recommended for the Next-Generation Caustic-Side is N,N',N'-tris(3,7-dimethyloctyl)guanidine (TiDG). Systematic testing has shown that it is significantly more lipophilic than the previously recommended guanidine DCiTG, the active extractant in the commercial guanidine product LIX -79, while not otherwise changing the solvent performance. Previous testing indicated that the extent of partitioning of the DCiTG suppressor to the aqueous strip solution is significantly greater than expected, potentially leading to rapid depletion of the suppressor from the solvent and unwanted organic concentrations in process effluents. Five candidate guanidines were tested as potential replacements for DCiTG. The tests included batch extraction with simulated waste and flowsheet solutions, third-phase formation, emulsion formation, and partition ratios of the guanidine between the solvent and aqueous strip solution. Preliminary results of a thermal stability test of the TiDG solvent at one month duration indicated performance approximately equivalent to DCiTG. Two of the guanidines proved adequate in all respects, and the choice of TiDG was deemed slightly preferable vs the next best guanidine BiTABG.

cesium↗

DOE OSTI2013

Sharp Interface Tracking in Rotating Microflows of Solvent Extraction

The objective of this project is to develop a specialized sharp interface tracking simulation capability for predicting interaction of micron-sized drops and bubbles in rotating flows relevant to optimized design of contactor devices used in solvent extraction processes of spent nuclear fuel reprocessing. The primary outcomes of this project include the capability to resolve drops and bubbles micro-hydrodynamics in solvent extraction contactors, determining from first principles continuum fluid mechanics how micro-drops and bubbles interact with each other and the surrounding shearing fluid for realistic flows. In the near term, this effort will play a central role in providing parameters and insight into the flow dynamics of models that average over coarser scales, say at the millimeter unit length. In the longer term, it will prove to be the platform to conduct full-device, detailed simulations as parallel computing power reaches the exaflop level. The team will develop an accurate simulation tool for flows containing interacting droplets and bubbles with sharp interfaces under conditions that mimic those found in realistic contactor operations. The main objective is to create an off-line simulation capability to model drop and bubble interactions in a domain representative of the averaged length scale. The technical approach is to combine robust interface tracking software, subgrid modeling, validation quality experiments, powerful computational hardware, and a team with simulation modeling, physical modeling and technology integration experience. Simulations will then fully resolve the microflow of drops and bubbles at the microsecond time scale. This approach is computationally intensive but very accurate in treating important coupled physical phenomena in the vicinity of interfaces. The method makes it possible to resolve spatial scales smaller than the typical distance between bubbles and to model some non-equilibrium thermodynamic features such as finite critical tension in cavitating liquids

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2013

Algal Lipid Extraction and Upgrading to Hydrocarbons Technology Pathway

In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This technology pathway case investigates the cultivation of algal biomass followed by further lipid extraction and upgrading to hydrocarbon biofuels. Technical barriers and key research needs have been assessed in order for the algal lipid extraction and upgrading pathway to be competitive with petroleum-derived gasoline, diesel and jet range hydrocarbon blendstocks.

algae↗

DOE OSTI2013

Soil Vapor Extraction System Optimization, Transition, and Closure Guidance

Soil vapor extraction (SVE) is a prevalent remediation approach for volatile contaminants in the vadose zone. A diminishing rate of contaminant extraction over time is typically observed due to 1) diminishing contaminant mass, and/or 2) slow rates of removal for contamination in low-permeability zones. After a SVE system begins to show indications of diminishing contaminant removal rate, SVE performance needs to be evaluated to determine whether the system should be optimized, terminated, or transitioned to another technology to replace or augment SVE. This guidance specifically addresses the elements of this type of performance assessment. While not specifically presented, the approach and analyses in this guidance could also be applied at the onset of remediation selection for a site as a way to evaluate current or future impacts to groundwater from vadose zone contamination. The guidance presented here builds from existing guidance for SVE design, operation, optimization, and closure from the U.S. Environmental Protection Agency, U.S. Army Corps of Engineers, and the Air Force Center for Engineering and the Environment. The purpose of the material herein is to clarify and focus on the specific actions and decisions related to SVE optimization, transition, and/or closure.

guidance↗

DOE OSTI2014

Selective Gaseous Extraction: Research, Development and Training for Isotope Production, Final Technical Report

General Atomics and the University of Missouri Research Reactor (MURR) completed research and development of selective gaseous extraction of fission products from irradiated fuel, which included training and education of MURR students. The process used porous fuel and after irradiation flowed product gases through the fuel to selectively removed desired fission products with the primary goal of demonstrating the removal of rhodium 105. High removal rates for the ruthenium/rhodium (Ru/Rh), tellurium/iodine (Te/I) and molybdenum/technetium (Mo/Tc) series were demonstrated. The success of this research provides for the reuse of the target for further production, significantly reducing the production of actinide wastes relative to processes that dissolve the target. This effort was conducted under DOE funding (DE-SC0007772). General Atomics objective of the project was to conduct R&D on alternative methods to produce a number of radioactive isotopes currently needed for medical and industry applications to include rhodium-105 and other useful isotopes. Selective gaseous extraction was shown to be effective at removing radioisotopes of the ruthenium/rhodium, tellurium/iodine and molybdenum/technetium decay chains while having trace to no quantities of other fission products or actinides. This adds a new, credible method to the area of certain commercial isotope production beyond current techniques, while providing significant potential reduction of process wastes. Waste reduction, along with reduced processing time/cost provides for superior economic feasibility which may allow domestic production under full cost recovery practices. This provides the potential for improved access to domestically produced isotopes for medical diagnostics and treatment at reduced cost, providing for the public good.

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2014

Next Generation Solvent Development for Caustic-Side Solvent Extraction of Cesium

This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Inter laboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2017

High temperature high velocity direct power extraction using an open-cycle oxy-combustion system

The implementation of oxy-fuel technology in fossil-fuel power plants may contribute to increased system efficiencies and a reduction of pollutant emissions. One technology that has potential to utilize the temperature of undiluted oxy-combustion flames is open-cycle magnetohydrodynamic (MHD) power generators. These systems can be configured as a topping cycle and provide high enthalpy, electrically conductive flows for direct conversion of electricity. This report presents the design and modeling strategies of a MHD combustor operating at temperatures exceeding 3000 K. Throughout the study, computational fluid dynamics (CFD) models were extensively used as a design and optimization tool. A lab-scale 60 kWth model was designed, manufactured and tested as part of this project. A fully-coupled numerical method was developed in ANSYS FLUENT to characterize the heat transfer in the system. This study revealed that nozzle heat transfer may be predicted through a 40% reduction of the semi-empirical Bartz correlation. Experimental results showed good agreement with the numerical evaluation, with the combustor exhibiting a favorable performance when tested during extended time periods. A transient numerical method was employed to analyze fuel injector geometries for the 60-kW combustor. The ANSYS FLUENT study revealed that counter-swirl inlets achieve a uniform pressure and velocity ratio when the ports of the injector length to diameter ratio (L/D) is 4. An angle of 115 degrees was found to increase distribution efficiency. The findings show that this oxy-combustion concept is capable of providing a high-enthalpy environment for seeding, in order to render the flow to be conductive. Based on previous findings, temperatures in the range of 2800-3000 K may enable magnetohydrodynamic power extraction. The heat loss fraction in this oxy-combustion system, based on CFD and analytical calculations, at optimal operating conditions, was estimated to be less than 10 percent. Furthermore, the heat transfer design removed approximately 7 MW/m2. The results observed in the lab-scale system were employed to develop a 1-MW scaled prototype. Scaling methods were based on critical design criteria found in similar systems, aimed at replicating combustion flow fields and reducing possible instabilities. A numerical simulation of the combustor wall was developed for a combined thermal steady model and static structural model. This combined model was developed predict combined stress parameters within the wall during testing conditions. Both models were developed within ANSYS FEA software package. The relative accuracy presented as well major performance parameters are discussed to assess the design's validity and ensure safety. The scaled prototype was manufactured through selective laser melting (SLM)-based additive manufacturing to reduce lead times and increase geometrical complexity. Additional CFD models were developed to optimize coolant manifold system parameters and perform a parametric study on channel geometry. An investigation on coolant manifold geometry demonstrated improvements in channel flow distribution when enlarging manifold lengths and increasing the number of tubes feeding into the flow. A three-dimensional model based on a single channel was developed to capture the effect of variable properties and thermal stratification. All cases in the simulation exhibited higher wall temperatures and lower convective coefficients than those determined through 1-D analytical equations. This implies that pressure and velocity safety factors must be implemented during system operation. Overall, the findings made in this investigation are thought to be of value to researchers and industrial practitioners when designing oxy-fuel direct power extraction systems operating at temperatures exceeding 3000 K. In addition to this, the implementation of the developed technology at pilot and commercial scales could result in a significant improvement in the efficiencies of heritage and next-generation power cycles.

03 NATURAL GAS↗

DOE OSTI2018

Extraction of Uranium from Seawater: Design and Testing of a Symbiotic System

The U.S. Department of Energy in October 2014 awarded the Massachusetts Institute of Technology (MIT) a Nuclear Energy University Program grant (DE-NE0008268) to investigate the design and testing of a symbiotic system to harvest uranium from seawater. As defined in the proposal, the goals for the project are: 1. Address the design of machines for seawater uranium mining. 2. Develop design rules for a uranium harvesting system that would be integrated into an offshore wind power tower. 3. Fabricate a 1/50th size scale prototype for bench and pool-testing to verify initial analysis and theory. 4. Design, build, and test a second 1/10th size scale prototype in the ocean for more comprehensive testing and validation. This report describes work done as part of DE-NE0008268 from 10/01/2014 to 11/30/2017 entitled, “Extraction of Uranium from Seawater: Design and Testing of a Symbiotic System.” This effort is part of the Seawater Uranium Recovery Program. This report details the publications and presentations to date on the project, an introduction to the project’s goals and background research into previous work done to achieve these goals thus far. From there, the report describes an algorithm developed during the project used to optimize the adsorption of uranium by changing mechanical parameters such as immersion time and adsorbent reuses is described. Next, a design tool developed as part of the project to determine the global feasibility of symbiotic uranium harvesting systems. Additionally, the report details work done on shell enclosures for uranium adsorption. Moving on, the results from the design, building, and testing of a 1/50th physical scale prototype of a highly feasible symbiotic uranium harvester is described. Then, the report describes the results from flume experiment used to determine the affect of enclosure shells on the uptake of uranium by the adsorbent they enclose. From there the report details the design of a Symbiotic Machine for Ocean uRanium Extraction (SMORE). Next, the results of the 1/10th scale physical scale prototype of a highly feasible symbiotic uranium harvester are presented. The report then details the design and results of an experiment to examine the hydrodynamic effects of a uranium harvester on the offshore wind turbine it is attached to using a 1/150th Froude scale tow tank test. Finally, the report details the results of an initial cost-analysis for the production of uranium from seawater from such a symbiotic device.

42 ENGINEERING↗

DOE OSTI2025

Rapid Sensing to Facilitate Purification of Rare Earth Element-Containing Process Streams Produced Through Membrane-Assisted Solvent Extraction

The development of an economically competitive domestic supply of rare earth elements and yttrium (REY) is necessary for our nation’s economic growth and national security. The achievement of a secure domestic supply of REY requires not only the development of effective processes for recovery of REY from naturally occurring materials and/or recycled products, but also the development of downstream processes for the ultimate production of high-REY content solids. An impediment to the development of such processes is the scarcity of analytical methods that provide rapid determination of the process stream compositions. In this work, a membrane-based extraction process was used to selectively recover REYs from a dilute solution in the presence of much higher concentrations of Ca and Al. In tandem, the use of a portable spectrometer equipped with an immobilized zinc adeninate benzene tricarboxylate metal-organic framework sensing material makes possible the rapid detection of the presence of ppm concentrations of Tb and Eu in both weakly acidic and strongly acidic process streams within minutes. A solvent extraction processing time of 15-60 min maximized REY selectivity over gangue ions while achieving up to 80% REY and minimal gangue ion recovery. Taken together, these experiments highlight not only an innovative method for REY purification but also the importance of inexpensive, portable characterization methods for near real-time analysis of REY content.

Membrane-assisted solvent extraction↗

DOE OSTI2026

Final Scientific/Technical Report: Simultaneous Lithium Extraction and Thin-Film Deposition of Lithium Metal for Low-Cost, High-Energy Anodes from Brine Resources

This report describes the scale-up and pilot validation of Alpha-En's Reductive Lithium Extraction (RLE) process, which directly converts lithium ions from aqueous brine-derived feedstocks into thin-film lithium metal anodes, demonstrating greater than 50% extraction efficiency, battery performance matching or exceeding commercial lithium metal controls in coin and pouch cells, and continuous roll-to-roll production of a meter-scale lithium metal anode strip.

25 ENERGY STORAGE↗

DOE OSTI2010

Radiation chemistry in solvent extraction: FY2010 Research

This report summarizes work accomplished under the Fuel Cycle Research and Development (FCR&D) program in the area of radiation chemistry during FY 2010. The tasks assigned during FY 2010 included: • Development of techniques to measure free radical reaction kinetics in the organic phase. • Initiation of an alpha-radiolysis program • Initiation of an effort to understand dose rate effects in radiation chemistry • Continued work to characterize TALSPEAK radiation chemistry Progress made on each of these tasks is reported here. Briefly, a method was developed and used to measure the kinetics of the reactions of the •NO3 radical with solvent extraction ligands in organic solution, and the method to measure •OH radical reactions under the same conditions has been designed. Rate constants for the CMPO and DMDOHEMA reaction with •NO3 radical in organic solution are reported. Alpha-radiolysis was initiated on samples of DMDOHEMA in alkane solution using He ion beam irradiation and 211At isotope irradiation. The samples are currently being analyzed for comparison to DMDOHEMA ?-irradiations using a custom-developed mass spectrometric method. Results are also reported for the radiolytic generation of nitrous acid, in ?-irradiated nitric acid. It is shown that the yield of nitrous acid is unaffected by an order-of-magnitude change in dose rate. Finally, recent results for TALSPEAK radiolysis are reported, summarizing the effects on solvent extraction efficiency due to HDEHP irradiation, and the stable products of lactic acid and DTPA irradiation. In addition, results representing increased scope are presented for the radiation chemistry program. These include an investigation of the effect of metal complexation on radical reaction kinetics using DTPA as an example, and the production of a manuscript reporting the mechanism of Cs-7SB radiolysis. The Cs-7SB work takes advantage of recent results from a current LDRD program to understand the fundamental chemistry of nitration under radiolysis conditions. Finally, work toward understanding the chemistry of irradiated formic acid is presented. This is important because all organic compounds eventually produce formic acid under long-term irradiation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗