SEARCH · Engineering Papers
Results for “FLIBE”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Corrosion of 316 stainless steel in high temperature molten Li2BeF4 (FLiBe) salt
Not Available
Density and Thermal Expansivity of Molten 2LiF-BeF 2 (FLiBe): Measurements and Uncertainty Quantification
Not Available
Modeling LiF and FLiBe Molten Salts with Robust Neural Network Interatomic Potential
Not Available
Thermodynamic and Transport Properties of LiF and FLiBe Molten Salts with Deep Learning Potentials
Not provided.
Method for the Determination of Oxygen in FLiBe via Inert Gas Fusion
Not Available
Approach to using 3D laser-induced breakdown spectroscopy (LIBS) data to explore the interaction of FLiNaK and FLiBe molten salts with nuclear-grade graphite
Nuclear graphite has historically been a key component of many nuclear reactor designs and has emerged as key to numerous advanced nuclear reactor design concepts. Molten salt reactors (MSRs) are one broad group of advanced reactor designs currently being pursued by industry for commercialization. Several MSR designs under consideration use graphitic materials that directly interface with a molten salt, whether it is a fuel salt, coolant salt, or both. Therefore, the interaction of graphite materials with molten salts must be understood. To gain this required understanding, a range of data is needed including porosity, strength, and composition as a function of different salt exposure parameters. In this study, a laser-induced breakdown spectroscopy (LIBS) measurement and data analysis methodology was developed to obtain spatially resolved elemental composition information for graphite samples exposed to a molten fluoride salt. Traditional univariate emission line analysis of atomic, ionic, and molecular optical emission signals was coupled via correlation analysis with spectral decomposition of the data using principal component analysis. Elemental depth profiling and elemental mapping were also performed to visualize salt–graphite interactions. LIBS was demonstrated to be useful for measuring key analytes such as fluorine and hydrogen, which are troublesome for other analysis techniques. Evidence for complex behavior was found, thereby demonstrating the usefulness of the developed approach for future systematic studies.
Complex Structure of Molten FLiBe (2 Li F – Be F 2 ) Examined by Experimental Neutron Scattering, X-Ray Scattering, and Deep-Neural-Network Based Molecular Dynamics
The use of molten salts as coolants, fuels, and tritium breeding blankets in the next generation of fission and fusion nuclear reactors benefits from furthering the characterization of the molecular structure of molten halide salts, paving the way to predictive capability of the chemical and thermophysical properties of molten salts. Due to its neutronic, chemical, and thermochemical properties, 2 Li F - Be F 2 is a candidate molten salt for several fusion- and fission-reactor designs. We performed neutron and x-ray total-scattering measurements to determine the atomic structure of liquid 2 Li F - Be F 2 . We also performed and neural-network molecular-dynamics simulations to predict the structure obtained by neutron- and x-ray-diffraction experiments. The use of machine learning provides improvements to the efficiency in predicting the structure at a longer length scales than is achievable with simulations at significantly lower computational expense while retaining near accuracy. We found that the NNMD simulations accurately predicted the Be F 4 2 − oligomer formations seen in the experimental first-structure-factor peak. Our combination of high-resolution measurements with large-scale molecular dynamics provided an avenue to explore and experimentally verify the intermediate-range ordering beyond the first-nearest neighbor that has posed too many experimental and computational challenges in previous works. With a deeper understanding of the salt structure and ion ordering, the evolution of salt chemistry over the lifetime of a reactor can be better predicted, which is crucial to the licensing and operation of advanced fission and fusion reactors that employ molten salts. To this end, this work will serve as a reference for future studies of salt structure and macroscopic properties with and without the addition of solutes. Published by the American Physical Society 2024
Characterization of a Thermodynamic Reference Electrode for Molten LiF-BeF 2 (FLiBe): Part II. Materials Analysis
Not Available
Tritium Extraction From a FLiBe IFE Blanket Using the CoRExt Process: Xcimer-SRNL INFUSE preliminary results
Explore the source record for details and available documents.
Electrochemical Evaluation of Hydrogen Concentration and Diffusivity in FLiBe
Final Report for INFUSE Project, DE-SC0024473
Compatibility of 316H in Static and Flowing FLiBe and FLiNaK Salts at 550°-650°C
Explore the source record for details and available documents.
Establishing a Database of High Temperature Salt Properties for Nuclear Applications
The Fluoride-Salt-Cooled High-Temperature Reactor (FHR) is a new reactor concept employing a high temperature liquid salt fluoride coolant. The thermophysical property data for candidate salt coolants is very limited. The uncertainties of these properties are quite high and not well documented. For researchers exploring reactor designs such as the FHR, a database of high temperature liquid salts for nuclear applications is being established. Researchers can use the database, which will be updated with new experimental data, to find thermophysical properties and associated uncertainties for salt coolants to use in their analyses. This paper serves as an introduction of the database and highlights the main three coolants in the database that are considered for use in the FHR design. The salts considered for the Fluoride-Salt-Cooled High- Temperature Reactor (FHR) include LiF-BeF{sub 2} (flibe) and NaFZrF{sub 4} (nafzirf) as potential primary loop coolants and LiF-NaFKF (flinak) as a secondary loop coolant. Flibe is the primary candidate for the primary loop coolant. It has the lowest neutron cross section, is chemically stable with low corrosion rates in high-nickel alloy systems, and is weakly radioactive with the primary activation product tritium resulting in very low radiation levels in the primary loop. Flibe does have some disadvantages, which include toxicity of beryllium and the need to enrich lithium to at least 99.995% Li-7 to maintain a low nuclear cross section. For design analysis, the baseline salt used is nafzirf because it has less attractive neutronic and thermophysical properties. The benefits of nafzirf over flibe including no direct tritium production and lower cost. By designing a reactor to operate using nafzirf, it is assumed that the reactor will operate better using flibe as the coolant. Thus, one can consider the coolants flibe and nafzirf to be bounding primary salt coolants for reactor design. (authors)
Temperature-Dependent Properties of Molten Li 2 BeF 4 Salt Using Ab Initio Molecular Dynamics
Molten lithium tetrafluoroberyllate (Li 2 BeF 4 ) salt, also known as FLiBe, with a 2:1 mixture of LiF and BeF 2 is being proposed as a coolant and solvent in advanced nuclear reactor designs, such as the molten salt reactor or the fluoride salt cooled high-temperature reactor. We present the results on the structure and properties of FLiBe over a wide range of temperatures, 0–2000 K, from high-throughput ab initio molecular dynamics simulation using a supercell model of 504 atoms. The variations in the local structures of solid and liquid FLiBe with temperature are discussed in terms of a pair distribution function, coordination number, and bond angle distribution. The temperature-dependent electronic structure and optical and mechanical properties of FLiBe are calculated. The optical and mechanical property results are reported for the first time. The results above and below the melting temperature (~732 K) are compared with the experimental data and with data for crystalline FLiBe. The electronic structure and interatomic bonding results are discussed in correlation with the mechanical strength. A novel concept of total bond order density (TBOD), an important quantum mechanical parameter, is used to characterize the internal cohesion and strength in the simulated models. The results show a variation in the rate of change in properties in solid and liquid phases with anomalous behavior across the melting region. The observed trend is the decrease in mechanical strength, band gap, and TBOD in a nonlinear fashion as a function of temperature. The refractive index shows a surprising minimum at 850 K, among the tested temperatures, which lies above the melting point. These findings provide a new platform to understand the interplay between the temperature-dependent structures and properties of FLiBe salt.
Microstructural Characterization of In-reactor Corrosion Tested Hastelloy N{sup R} and 316 Stainless Steel
The success of the Molten Salt Reactor Experiment (MSRE) at the Oak Ridge National Laboratory (ORNL) in the period 1950's-70's has rekindled the interested in molten salt-cooled reactors. The most recent form of this type of reactor, the Fluoride salt-cooled High-temperature nuclear Reactors (FHRs) is emerging as a leading reactor concept for the next generation nuclear reactors because it offers, among other benefits, a high degree of passive safety, high thermal efficiency, and low spent fuel. Since 2011, two three-year Integrated Research Projects (IRPs) were awarded by the U. S. Department of Energy (DoE) to the Massachusetts Institute of Technology (MIT) in partnership with the University of California, Berkeley and the University of Wisconsin-Madison to develop a 'path forward' for the development of the FHR. One primary challenge in these projects is to evaluate the corrosion and compatibility of structural alloys in the potential primary coolant of molten Li{sub 2}BeF{sub 4} (FLiBe) salt at 700 deg. C in a neutron irradiation environment. In support of structural materials development for the FHR, the static in-reactor corrosion tests of two promising alloys, nickel-based Hastelloy N{sup R} and 316 stainless steel, in {sup 7}Li-enriched molten FLiBe have been conducted in both metal-lined and graphite crucibles in the MIT nuclear research reactor in 2013. This work focuses on the microstructural characterization of the in-reactor corrosion tested alloys for understanding of their performance in high-temperature molten FLiBe salt. Our preliminary results indicate significant thermal effects, graphite effects, and irradiation effects on the alloys' performance in high-temperature molten FLiBe salt, particularly for the in-reactor corrosion tests. The neutron irradiation induces tritium generation in molten salt which could combine with fluorine ions to form corrosive HF to dramatically attack alloys. Additionally, the neutron irradiation introduces structural defects into alloys which probably alter alloys' corrosion resistivity to high temperature molten FLiBe salt. The effect of graphite on the alloys' corrosion in a nuclear reactor is also possibly different from the out-of-reactor corrosion. All these issues will be better understood by characterizing the microstructure of in-reactor corrosion tested alloy samples in our near future plans. The experimental data in this study provides valuable input for evaluating structural materials performance in the FHR. (authors)