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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 1,729 records · Page 96
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Reaction of Antimony-Uranium Composite Oxide in the Chlorination Treatment of Waste Catalyst - 13521

The effect of oxygen gas concentration on the chlorination treatment of antimony-uranium composite oxide catalyst waste was investigated by adding different concentrations of oxygen at 0-6 vol% to its chlorination agent of 0.6 or 6 vol% hydrogen chloride gas at 1173 K. The addition of oxygen tended to prevent the chlorination of antimony in the oxide. When 6 vol% hydrogen chloride gas was used, the addition of oxygen up to 0.1 vol% could convert the uranium contained in the catalyst to U{sub 3}O{sub 8} without any significant decrease in the reaction rate compared to that of the treatment without oxygen. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

Comparative Evaluation of Cutting Methods of Activated Concrete from Nuclear Power Plant Decommissioning - 13548

The amount of radioactive wastes from decommissioning of a nuclear power plant varies greatly depending on factors such as type and size of the plant, operation history, decommissioning options, and waste treatment and volume reduction methods. There are many methods to decrease the amount of decommissioning radioactive wastes including minimization of waste generation, waste reclassification through decontamination and cutting methods to remove the contaminated areas. According to OECD/NEA, it is known that the radioactive waste treatment and disposal cost accounts for about 40 percentage of the total decommissioning cost. In Korea, it is needed to reduce amount of decommissioning radioactive waste due to high disposal cost, about $7,000 (as of 2010) per a 200 liter drum for the low- and intermediate-level radioactive waste (LILW). In this paper, cutting methods to minimize the radioactive waste of activated concrete were investigated and associated decommissioning cost impact was assessed. The cutting methods considered are cylindrical and volume reductive cuttings. The study showed that the volume reductive cutting is more cost-effective than the cylindrical cutting. Therefore, the volume reductive cutting method can be effectively applied to the activated bio-shield concrete. (authors)

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DOE OSTI2013

Lessons Learned on University Education Programs of Chemical Engineering Principles for Nuclear Plant Operations - 13588

University education aims to supply qualified human resources for industries. In complex large scale engineering systems such as nuclear power plants, the importance of qualified human resources cannot be underestimated. The corresponding education program should involve many topics systematically. Recently a nuclear engineering program has been initiated in Dongguk University, South Korea. The current education program focuses on undergraduate level nuclear engineering students. Our main objective is to provide industries fresh engineers with the understanding on the interconnection of local parts and the entire systems of nuclear power plants and the associated systems. From the experience there is a huge opportunity for chemical engineering disciple in the context of giving macroscopic overview on nuclear power plant and waste treatment management by strengthening the analyzing capability of fundamental situations. (authors)

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DOE OSTI2012

Small Scale Mixing Demonstration Batch Transfer and Sampling Performance of Simulated HLW - 12307

The ability to effectively mix, sample, certify, and deliver consistent batches of High Level Waste (HLW) feed from the Hanford Double Shell Tanks (DST) to the Waste treatment Plant (WTP) has been recognized as a significant mission risk with potential to impact mission length and the quantity of HLW glass produced. At the end of 2009 DOE's Tank Operations Contractor, Washington River Protection Solutions (WRPS), awarded a contract to EnergySolutions to design, fabricate and operate a demonstration platform called the Small Scale Mixing Demonstration (SSMD) to establish pre-transfer sampling capacity, and batch transfer performance data at two different scales. This data will be used to examine the baseline capacity for a tank mixed via rotational jet mixers to transfer consistent or bounding batches, and provide scale up information to predict full scale operational performance. This information will then in turn be used to define the baseline capacity of such a system to transfer and sample batches sent to WTP. The Small Scale Mixing Demonstration (SSMD) platform consists of 43'' and 120'' diameter clear acrylic test vessels, each equipped with two scaled jet mixer pump assemblies, and all supporting vessels, controls, services, and simulant make up facilities. All tank internals have been modeled including the air lift circulators (ALCs), the steam heating coil, and the radius between the wall and floor. The test vessels are set up to simulate the transfer of HLW out of a mixed tank, and collect a pre-transfer sample in a manner similar to the proposed baseline configuration. The collected material is submitted to an NQA-1 laboratory for chemical analysis. Previous work has been done to assess tank mixing performance at both scales. This work involved a combination of unique instruments to understand the three dimensional distribution of solids using a combination of Coriolis meter measurements, in situ chord length distribution measurements, and electro-resistive tomography. This current work utilized the same instruments to monitor simulated waste transfers. This paper will discuss some of the scaling compromises when it came to the scaled sampling system design, handling of large quantities of material for sampling, and present data for the discuss of likely behavior of the full scale DST based on scaling correlations using a scale ratio exponent (SRE) from 0.25 to 0.45 and the behavior observed in the SSMD platform. This does not establish a scaling factor for DST mixing using paired jet mixers but is an attempt to envelope the likely performance ranges in terms of certification sampling bias, certification sample root-mean-square-deviation, and bath to batch relative standard deviation. (authors)

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DOE OSTI2012

Demonstration of Mixing and Transferring Settling Cohesive Slurry Simulants in the AY-102 Tank - 12323

In support of Hanford's feed delivery of high level waste (HLW) to the Waste Treatment and Immobilization Plant (WTP), pilot-scale testing and demonstrations with simulants containing cohesive particles were performed as a joint collaboration between Savannah River National Laboratory (SRNL) and the Pacific Northwest National Laboratory (PNNL) staff. The objective of the demonstrations was to determine the impact that cohesive particle interactions in the simulants, and the resulting non- Newtonian rheology, have on tank mixing and batch transfer of large and dense seed particles. The work addressed the impacts cohesive simulants have on mixing and batch transfer performance in a pilot-scale system. Kaolin slurries with a range of wt% concentrations to vary the Bingham yield stress were used in all the non-Newtonian simulants. To study the effects of just increasing the liquid viscosity (no yield stress) on mixing and batch transfers, a glycerol/water mixture was used. Stainless steel 100 micron particles were used as seed particles due to their density and their contrasting color to the kaolin and glycerol. Testing results show that water always transfers less seed particles, and is conservative when compared to fluids with a higher yield stress and/or higher viscosity at the same mixing/transfer parameters. The impact of non-Newtonian fluid properties depends on the magnitude of the yield stress. A higher yield stress in the carrier fluid resulted in more seed particles being transferred to the RTs. A dimensional analysis highlighting the role of a yield stress (due to cohesive particle interactions) defined four regions of behavior and indicates how the results obtained in this study can be applied to the full-scale mixing behavior of a high level waste tank. The analysis indicates that the regions of behavior for full-scale mixing have been adequately represented by the current small-scale tests. (authors)

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DOE OSTI2012

Riparian and Upland Restoration at the U.S. Department of Energy Rocky Flats, Colorado, Site - 12360

Remedial investigation and cleanup at the Rocky Flats, Colorado, Site was completed in 2005. Uplands, riparian, and wetland habitat were disturbed during cleanup and closure activities and required extensive revegetation. Unavoidable disturbances to habitat of the Preble's meadow jumping mouse (a federally listed species) and wetlands required consultation with regulatory agencies and mitigation. Mitigation wetlands were constructed in two drainages, and a third developed naturally where a soil borrow area intercepted the groundwater table. During the 50-plus years of site operations, 12 ponds were constructed in three drainages to manage and retain runoff and sewage treatment plant discharges prior to release off site. A batch-release protocol has been used for the past several decades at the terminal ponds, which has affected the riparian communities downstream. To return the hydrologic regime to a more natural flow-through system similar to the pre-industrial-use conditions, seven interior dams (of 12) have been breached, and the remaining five dams are scheduled for breaching between 2011 and 2020. At the breached dams, the former open water areas have transformed to emergent wetlands, and the stream reaches have returned to a flow-through system. Riparian and wetland vegetation has established very well. The valves of the terminal ponds were opened in fall 2011 to begin flow-through operations and provide water to the downstream plant communities while allowing reestablishment of vegetation in the former pond bottoms prior to breaching. A number of challenges and issues were addressed during the revegetation effort. These included reaching an agreement on revegetation goals, addressing poor substrate quality and soil compaction problems, using soil amendments and topsoil, selecting seeds, determining the timing and location of revegetation projects relative to continuing closure activities, weed control, erosion control, revegetation project field oversight, and contractual limitations. A variety of ecological restoration techniques were conducted at the site to meet these challenges. These efforts have resulted in vegetation becoming well established in most locations. (author)

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DOE OSTI2017

Current Efforts in Immobilized Low-Activity Waste Glass Testing to Support the Hanford Site Integrated Disposal Facility - 17119

Cleanup plans for Hanford site high-level radioactive mixed tank waste calls for separating the waste into high-level waste (HLW) and low-activity waste (LAW) fractions. The fractions will be vitrified separately at the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The HLW glass will be sent to an offsite geological disposal facility while the immobilized low-activity waste (ILAW) glass will be disposed at the onsite Integrated Disposal Facility (IDF). In order to inform models used to predict the performance of ILAW glass at IDF, it is necessary to understand the corrosion behavior of the glass. In this paper, we discuss tests that account for the effects of 1) solution chemistry, 2) the ion exchange reaction, and 3) secondary phase formation on the glass dissolution rate. To quantify the effects of solution chemistry, specifically changes in pH, T, and Si concentration, the single-pass flow-through (SPFT) test method is applied. A designed set of these tests results in a set of kinetic rate law parameters that are used in a glass dissolution rate law based on transition-state theory. Furthermore, for SPFT tests with relatively high concentrations of Si, an ion exchange rate is provided. Additionally, through tests such as the pressurized unsaturated flow (PUF) test method, a suite of secondary phases can be compiled. The collection of kinetic rate law parameters, the ion exchange term, and the suite of secondary phases are provided to IDF performance assessment (PA) modelers. Lastly, we present a description of the efforts made to verify and validate the use of these parameters and secondary phases through the use of a field lysimeter present at the Hanford site. (authors)

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DOE OSTI2017

Low Activity Waste Pretreatment System Bench-Scale Testing: Supporting Integrated Testing and Facility Safety Analyses - 17171

The Low Activity Waste Pretreatment System (LAWPS) is being designed to enable the direct feed of waste to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) facility to be immobilized. Prior to construction of the LAWPS, pilot-scale integrated testing of the key unit operations (crossflow filtration, ion exchange using spherical resorcinol-formaldehyde (sRF) resin) will be conducted by a team led by Washington River Protection Solutions (WRPS) to increase the technology maturation level of the facility's critical technology elements. As a part of this effort, Pacific Northwest National Laboratory (PNNL) has conducted a series of tests to perform two major objectives: (1) support pilot-scale integrated testing of the LAWPS by supplying information or performance data in advance of operating the pilot-scale facility (1/9. scale); and (2) collect data needed to establish or confirm assumptions/approaches planned for implementation in the LAWPS safety basis. The first objective was focused in two technical areas: developing simulants that are representative of expected waste feed and can be produced at larger scales, and using these simulants in a bench-scale crossflow filter to establish expected solid-liquid separation performance. The crossflow filter was also used to observe the efficacy (with respect to filter production rate) of selected operational strategies. The second objective also included two technical areas: measuring the effect of sRF resin on hydrogen generation rate under irradiation, and demonstrating that the planned hydrogen management approach is effective and robust. The hydrogen management strategy involves fluidization of the sRF resin bed in the ion exchange columns and recirculating the liquid, a scenario that is planned for testing at full column height. The full height tests at PNNL also supported full-scale IX column testing conducted as part of the technology maturation plan. The experimental approaches used at PNNL in these four technical areas are summarized and selected key preliminary results are provided. (authors)

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DOE OSTI2017

Use of Layered Double Hydroxide (LDH) Sorbents to Remove Radioactive Iodine Species - 17178

To more efficiently manage the radioactive iodine waste, layered double hydroxides (LDHs) were synthesized and characterized using XRD, FT-IR, SEM-EDS, and ICP-AES. Batch adsorption experiments to remove I{sup -} and IO{sub 3}{sup -} under DIW condition were conducted to check overall removal efficiencies with and without calcination using ICP-MS. Synthesized MgFe-Cl-C-21 LDHs consisting of Mg{sup 2+} and Fe{sup 3+} in a 2:1 concentration ratio of the divalent ion to the trivalent ion after calcination showed the highest I- removal efficiency, 89.2 % and synthesized CoCr-Cl-NC-41 LDHs consisting of Co{sup 2+} and Cr{sup 3+} in a 4:1 concentration ratio of the divalent ion to the trivalent ion without calcination showed the highest IO{sub 3}- removal efficiency, 97.0 %. (authors)

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DOE OSTI2017

Direct Feed Options for Hanford High Level Waste Vitrification - 17318

In the high level waste (HLW) direct feed (DF) option that is under consideration for early operations of the Hanford Tank Waste Treatment and Immobilization Plant (WTP), the pretreatment facility would be bypassed in order to support an earlier start-up of the HLW vitrification facility. For HLW, this would mean that the ultrafiltration and caustic leaching operations that would otherwise have been performed in the pretreatment facility would either not be performed or would be replaced by an interim pretreatment function (in-tank washing and settling, for example). These changes could result in higher aluminum contents, higher chromium contents, a higher fraction of supernate in the HLW feed, and lower solids contents. This would likely affect glass formulations and waste loadings and have impacts on the downstream vitrification operations. In the present work, new high waste loading glass formulations have been developed and characterized for the DF HLW option. A series of scaled melter tests was then conducted to assess the impacts of increased supernate content resulting from less effective washing on wastes from candidate source tanks for the direct feed option. The melter tests were conducted at solids contents extending below the current WTP baseline, which are likely for the direct feed option. The effects on glass production rate, melter operations, and off-gas carryover were determined, as was the ability of increased bubbling to compensate for the increased evaporative load. A series of waste compositions were investigated that span the range of in-tank washing efficiencies between the baseline WTP full-wash case and the no-wash case. The tests included wastes from tank AY-102 as well as high plutonium wastes from tank A-104. The results from this work provide the initial basis for assessments of the relative merits of progressively more intensive pretreatment in HLW direct feed options versus the practical benefits of minimal pretreatment. Together, these results illustrate that the optimum washing strategy will depend on the specific tank waste composition and will need to be evaluated on a tank-by-tank basis. (authors)

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DOE OSTI2017

Engaging the Public on Complex Issues: Communication challenges and Solutions - 17521

Public buy-in and support can make or break a project that has local environmental effects and implications, especially if that project takes place in a large community that is in-touch with its local and national government. Because of this, effective public communication is essential to the future of projects that can have an impact on a local community. This paper addresses the challenges and methods of communicating complex, scientific and/or technical issues with the public in an easy-to-understand, engaging manner while still accomplishing the communication goals of the organization. For consideration in particular is the challenge of communicating the proposed path forward and ongoing progress being made at ORP's tank farms and Waste Treatment and Immobilization Plant project to help build support and acceptance with local and national audiences. By using a variety of engagement opportunities and communication tools, we are able to educate the public on the issues being addressed by the organization, the possible solutions to these issues, and the challenges involved. An engaged and well-informed public can assist the organization in accomplishing its mission by educating and influencing audiences that have an impact on the organization. (authors)

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DOE OSTI2015

Novel inorganic sorbent for iodine removal in pump and treat system - 15020

The radioisotope {sup 129}I is one of the key risk components in the migrating subsurface plumes present in the Hanford Site vadose zone due to its long half-life, large inventory, high toxicity, and high mobility in the aquifer. Removal of iodine from groundwater in the 200 Area is an essential component for managing the Hanford Site cleanup and protecting the Columbia River. In the subsurface aquatic environment it mainly exist as iodide, iodate, and organic derivatives of iodine. Because of different chemical properties of these species and significantly lower concentration than other constituents in the subsurface plumes their removal using commercial ion exchange resins is problematic. In addition, availability of a stable matrix for a long-term waste form for iodine is needed. Novel engineered inorganic composites that possess superior characteristics including large surface area, high sorption capacity, and good chemical-mechanical-thermal stability may potentially offer a solution. These two-in-one novel materials can be designed to serve as an efficient sorbent for the simultaneous removal of the dissimilar iodine species and a durable waste form under environmentally relevant conditions. This paper describes our current results on identification, characterization, and testing of the iodine-selective inorganic sorbents. (authors)

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DOE OSTI2015

Benefits from R. and D. for D. and D. projects - 15089

CEA (French Alternative Energies and Atomic Energy Commission) is both the operator of important nuclear facilities all over the nuclear cycle, in charge of major new built or D and D projects and a R and D group with dynamic policy of technology transfer: second in France for patents deposit, active partnership agreements with industries, and support for Start-ups. The position of CEA in D and D is unique because of the number and the wide diversity of facilities under decommissioning, with some high level of contamination. Innovative solutions are being developed in 6 main axes to protect the operators, to minimize the overall costs and the volumes of waste: - Investigations in the facilities - Radiological measurement of waste - Robotics, laser cutting devices, virtual reality to simulate and choose the best way to operate, - Decontamination of soils and structures - Waste treatment and conditioning - Methods and Information Technology (IT)Tools for project and waste management The last developments are shown and examples of industrial applications given: encapsulation of Magnesium or vitrification of high level waste for UP1 retreatment plant, treatment of sodium for Phenix fast breeder, treatment of organic liquids, etc. CEA is willing to share actions in partnership with other operators or with industrials so they can use the results for other contracting authorities. (authors)

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DOE OSTI2015

Improving high level waste solids mobilization and transfer through Hanford double-shell tanks - 15099

The Hanford Tank Operations Contractor (TOC) and the Hanford Waste Treatment and Immobilization Plant (WTP) contractor are both engaged in demonstrating mixing, sampling, and transfer system capabilities using simulated Hanford High-Level Waste (HLW) formulations. Efficient and effective handling of solid radioactive waste is essential to the successful completion of River Protection Project (RPP) mission and the Department of Energy's Hanford site. The TOC ust transfer over 416 million liters (110 million gallons) of HLW slurry through a complex system of 28 double shell tanks (DSTs) of approximately 3.8 million liters (1 million gallons) each as it is staged and delivered to the WTP. Through the use of scaled tanks and non-radioactive simulants, the TOC has identified operational methodologies for mixer pumps that enhance the movement of the solids through the DST system which will minimize the amount of solids remaining for final tank closeout. (authors)

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DOE OSTI2015

Selective separation of Sr by potassium titanates from solution of nitrate - 15248

The radioactive waste treatment is planned in LWTF (Low-level radioactive Waste Treatment Facility, JAEA) for the low-level liquid wastes generated from Tokai-reprocessing facility [1]. The target liquid wastes mainly consist of highly concentrated sodium nitrate (4.7 M NaNO{sub 3}) containing low level radioactive {sup 137}Cs and {sup 90}Sr, while the conventional adsorbent (Titanic acid-PAN) has some problems in the adsorption performance and irradiation resistance. In this study, the adsorption properties of Sr{sup 2+} ions, leaching properties of Sr{sup 2+} and irradiation properties were clarified by using the novel adsorbent of potassium titanates (KT-1). Relatively large uptake percentage (99%) and maximum uptake capacity (0.37 mmol/g) were obtained for the KT-1 compared to that of Titanic acid-PAN. As for the breakthrough properties, KT-1 had the smoother breakthrough carve and larger 5% breakthrough capacity compared to Titanic acid-PAN. From the results of batch and column experiments, KT-1 was effective for the uptake of Sr{sup 2+} ions in the presence of highly concentrated Na{sup +} ions. The leached percentages of Sr{sup 2+} ions form calcined products of Sr-KT-1 in pure water and 0.1 M NaOH were less than the detection limit of ICP-AES, and those in 0.1 M HCl tended to markedly decrease with calcining temperature; the formation of SrTiO{sub 3} phase above 800 deg. deg. C was effective for the lowering of leachability. The irradiation stability of the adsorbent was examined by instrumental analyses and the evaluation for the uptake percentage of Sr{sup 2+} ions by batch method. The growth of surface crystal was observed by SEM, but no significant change in X-ray diffraction peak was observed, and Sr{sup 2+} uptake (%) was almost constant. The novel adsorbent of KT-1 had excellent characteristics for Sr selectivity, uptake capacity, leachability and irradiation resistance. KT-1 is thus effective for the treatment and disposal in LWTF. (authors)

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DOE OSTI2015

Managing the interfaces for successful waste treatment operations at the river protection project - 15347

The Department of Energy (DOE) is constructing the Waste Treatment and Immobilization Plant (WTP) at the Hanford site in Washington to treat and immobilize(vitrify) approximately 432 million liters (114 million gallons) of high level radioactive waste (after all single-shell retrievals are accomplished). The tank operating contractor (TOC) is charged with delivering feed, with preconditioning if required. Other Hanford contractors are charged with providing utilities and other services and waste disposal facilities. In all, four DOE contractors, two DOE offices along with DOE headquarters, and two Washington state regulators play essential roles in enabling successful treatment operations eliminate the radioactive and hazardous waste threats to the public and the environment. DOE has decided that the appropriate approach is to proceed with operations at the WTP's Low-Activity Waste (LAW) vitrification facility ahead of completing the WTP Pretreatment and High Level Waste (HLW) waste vitrification facilities, This paper outlines the approach that is being taken to ensure that all the functions, reviews, and approvals needed for radioactive operations are achieved to allow successful feed delivery, startup, and operations of the WTP in a direct feed to LAW mode. A massive effort is needed to be successful and a One System organization, jointly managed and staffed by WTP and TOC personnel is tasked with achieving the integration, coordination, tracking, and reporting necessary for the endeavor. (authors)

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DOE OSTI2015

Technetium and iodine getters to improve Cast Stone performance - 15420

Technetium-99 ({sup 99}Tc) and iodine-129 ({sup 129}I) have been determined to be tank waste components contributing most to the environmental impacts associated with the cleanup of the Hanford site. Cast Stone, which has the ability to immobilize {sup 99}Tc, {sup 129}I, and other contaminants of concern, is being considered as a low temperature waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) An environmental assessment of Cast Stone performance, using measured diffusivities of the radionuclides from the Cast Stone product, calculates groundwater at the 100 m down-gradient in excess of the allowable maximum permissible concentrations for both radionuclides. Therefore, an opportunity exists to improve the performance of Cast Stone. One method for improvement is through the addition of immobilizing agents known as 'getters' that selectively sequester Tc and I. In the present paper, we report on seven getter materials that have been tested for Tc and five materials that have been tested for I to determine their effectiveness for radionuclide removal in a series of batch sorption tests in 18.2 MΩ DI H{sub 2}O and a 7.8 M Na Ave LAW waste simulant. Contact experiments have been carried out in anoxic conditions at room temperature, with varying solid-to-solution ratios, and in the presence and absence of competing species. Results indicate that most materials perform better in the 18.2 MΩ DI H{sub 2}O compared to the 7.8 M Na LAW waste simulant for both Tc and I getter. Radionuclide sequestration may be affected by the presence of the redox sensitive Cr(VI) in the simulant. The top performing Tc getter materials, Sn(II)-apatite, BFS-2, KMS-2 and Sn-hydroxyapatite, were examined through various solid-state characterization techniques such as SEM/XEDS, XANES and EXAFS. Tc removal is theorized to occur through reduction of the highly soluble Tc(VII) species to the less soluble Tc(IV). Solution results from the series of I tests show that iodide is effectively removed from solution via, most likely, a precipitation reaction of AgI. A wide range of I getter materials and the silver exchanged zeolite getter performed well in both DI water and the simulant. (authors)

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