Interaction Of Beryllium Research Articles

Humidity effects on neutron irradiated beryllium

This study focuses on neutron-irradiated beryllium interactions with air of differing humidity, simulating water cooled fusion reactor malfunction.Beryllium in the form of ∼ 1 mm ∅ pebbles has been used in the study. Both non-irradiated and neutron-irradiated pebbles were thermally treated and studied using thermogravimetric/differential thermal analysis in dry airflow with relative humidity (RH) < 5 % and humid > 90% RH.Surface structure and composition was investigated with scanning electron microscopy (SEM) and energy dispersion X-ray spectrometry (EDX). Tritium release was monitored using a tritium monitor.Results show that elevated RH coupled with neutron irradiation damage on beryllium yields the largest mass increase of 180% (in relation to the initial mass) compared to non-irradiated Be treated in RH < 5% which resulted in 3 % mass increase. SEM and EDX revealed a substantial number of cracks as well as the formation of irregular shape micro-/nanoparticles of BeO. Tritium release took place at temperatures above ∼ 1040 K, reaching a peak after 1263 K. Overall tritium inventory was estimated to be up to 1.08∙1017 T atoms/g.

Molecular Dynamics Study of the Beryllium Interaction with C-S-H Phases

Beryllium has applications in fission and fusion reactors, and accordingly it is expected in specific waste streams in nuclear waste repositories. As a part of the multi-barrier system, cementitious materials were shown to strongly sorb beryllium, but the precise uptake mechanisms remain ill-defined. Computational simulations were used to study Be(II) uptake by calcium-silicate-hydrate (C-S-H) phases. Molecular dynamics (MD) calculations show that Be(II) sorbs on (001), (004), and (100) C-S-H surfaces through Ca-bridges and hydrogen bonds. Energy profiles indicate that surface complexes with the highest number of Ca-bridges are the most stable. MD simulations support also Be(II) retention in the C-S-H interlayer. Be(OH)3– is predominantly bound through the exchange of water molecules for deprotonated silanol groups or through multiple Ca-bridges, whereas Be(OH)42– is immobilized in the interlayer midplane. These results provide key inputs to understand the mechanisms driving Be(II) uptake by cementitious materials of relevance in the context of nuclear waste disposal.

Interaction of beryllium with 316H stainless steel in molten Li2BeF4 (FLiBe)

The increased demand in renewable energy resources has led to a renewed interest in nuclear reactors including a new generation of molten salt reactors. One of the issues encountered in handling of molten chloride or fluoride salts is the inability of metals to form and retain a protective oxide surface layer, generally chromium oxide. The low chromium content, nickel-based alloy INOR-8, later marketed as Hastelloy N, was specifically developed to contain molten fluorides. This alloy had some deficiencies, but its composition resulted in it incurring far less chromium depletion by the molten fluoride salts than alloys like 316 stainless steel. For the next generation of molten salt reactors, an alloy with pressure vessel code approval and higher temperature capability than Hastelloy N is required. Consequently, several reactor designers have reportedly chosen to build the reactor containment vessel from 316H stainless steel. In order to minimize corrosion of the stainless steel by the molten fluoride salt (2LiF-BeF2), it is proposed to add beryllium metal to the salt to react with impurities and provide a means to lower the oxidation potential thus making the salt less corrosive. However, there is a concern whether the beryllium would react with components of the stainless steel. To address this concern, static capsule tests were conducted in which selected amounts of beryllium were added to capsules containing 2LiF-BeF2 (FLiBe) salt and 316H stainless steel and Hastelloy N samples. Following exposure, the samples were cleaned and examined using a variety of analysis techniques including, optical microscopy, SEM-EDS, XPS, LIBS, XRD and EPMA. Tensile samples were also exposed in capsules, and those were subjected to tensile testing. It was found that for the level of beryllium additions used in this study, intermetallic compounds were formed which could be detrimental to the long-term performance of the 316H stainless steel.

Coupled cluster investigation of the interaction of beryllium, magnesium, and calcium with pyridine: Implications for the adsorption on nitrogen-doped graphene

We performed benchmark calculations to study the complexes of pyridine with beryllium, magnesium, and calcium. In all cases, the σ structures, in which the alkaline-earth element interacts with nitrogen, were found to be more stable than the ones featuring interactions with the π cloud. At the CCSD(T)/CBS level of theory, the dissociation energies (De) are 6.5, 3.7 and 7.2 kcal/mol, for beryllium, magnesium, and calcium, respectively. Our estimation of the D0 of the calcium-pyridine complex is in excellent agreement with the experimental value. For comparative purposes, we studied the performance of the M06-2X, PBE-D3BJ, vdW-DF, and B2PLYP-D2BJ density functionals. All of the DFT methods employed significantly overestimated the dissociation energies. Finally, in light of the results obtained, pyridinic nitrogen is the doping configuration to be chosen in nitrogen-doped graphene to improve the adsorption of alkaline-earth elements on this material.

A molecular dynamics simulation of wear mechanism of diamond tool in nanoscale cutting of copper beryllium

In the present study, molecular dynamics simulation (MDS) is employed to study the wear mechanism of single crystal diamond tool during nanocutting of copper beryllium (CuBe). Two edge configurations, i.e., both sharp and worn out tools, are chosen to study the tool and workpiece interaction during the nanocutting of CuBe. Further, the study involves the experimental characterization techniques viz. scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy to confirm the simulation results. The results of the molecular dynamics simulation (MDS) show that the presence of Be as a hard particle in workpiece material influences the cutting forces which subsequently causes degradation of the sharp edge of the diamond tool. Furthermore, the carbon (C) atoms removed from the tool react with Be particles and as a result, it causes the formation of beryllium carbide (BeC). Beryllium interaction with the blunt edge configuration of the tool causes amorphization at the tool edge. Raman spectroscopy of the used diamond tool on CuBe reveals the similar phenomena of amorphization of the diamond at the tool edge. Moreover, surface generation is dependent on the tool edge condition as blunt edge tool leads to smoother surface compared to the surface generated by sharp edge configuration.

Evaluation of Cross Section of 10Be Radioactive Nuclei Production at Deuteron Interaction with 9Be

The demand for more precise nuclear data on beryllium interactions is growing along with the development of controlled fusion facilities, where beryllium is already used or is planned to be used as a structural material in the coating of the first inner wall of the tokamak (the tritium breeding blanket). Evaluated cross sections of the 9Be(d, x)10Begs reaction at deuteron energies ranging from 0 to 22 MeV are presented. All available experimental data and the mathematical tools of the SaBa [1] electronic library developed at the Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics are used to obtain these cross sections.

Paving a way to suppress hydrogen blistering by investigating the hydrogen–beryllium interaction in tungsten

We propose that beryllium (Be)-doping/pre-irradiation is a good choice to reduce hydrogen (H) retention and suppress H blistering in tungsten by investigating the Be–H interaction.

Interaction Between U-Mo Alloys and Alloys Al-Be

The main objective of the work is the experimental determination of the effect of doping on the kinetics of the interaction of beryllium, aluminum and uranium-molybdenum alloy dispersed in the nuclear fuel. It is shown that an increase in the content of Be in Al leads to a linear decrease in the rate of interaction of the alloy with uranium-molybdenum alloy. Besides AlBe-alloys have higher thermal and mechanical properties than other matrix alloys such as AlSi.

The interaction of beryllium with benzene and graphene: a comparative investigation based on DFT, MP2, CCSD(T), CAS-SCF and CAS-PT2

The interaction of beryllium with benzene, graphene and graphitic compounds involves multi-reference electronic states, Jahn-Teller distortion, charge transfer and van der Waals interactions. This is investigated herein using periodic and molecular models at different levels of theory: (i) the second-order Møller-Plesset (MP2) perturbation theory, (ii) the coupled cluster method with inclusion of single double and perturbative triple excitations (CCSD(T)), (iii) the complete active space self-consistent field (CAS-SCF) and (iv) the complete active space with perturbation theory truncated at the 2nd order (CAS-PT2). Molecular and periodic Density Functional Theory (DFT) methods are also used. The two major failures of DFT are addressed with regard to the beryllium benzene and graphene interaction: the degeneracy problem is the source of no specific problem while the delocalization error causes DFT with the Perdew Burke, Ernzerhof functional plus the Grimme correction (DFT/PBE-D2) to be over-binding by about 0.4 eV at a short-range. The agreement between DFT/PBE-D2 and wave-function based methods is nevertheless good; DFT/PBE-D2 provides an accurate description of the electronic structure of the system. By the end of this work, we shall get a better insight into the mechanisms leading beryllium to physisorb on graphene and to chemisorb into the bilayer of graphite.

Adsorption of beryllium atoms and clusters both on graphene and in a bilayer of graphite investigated by DFT

We herein investigate the interaction of beryllium with a graphene sheet and in a bilayer of graphite by means of periodic DFT calculations. In all cases, we find the beryllium atoms to be more weakly bonded on graphene than in the bilayer. Be2 forms both magnetic and non-magnetic structures on graphene depending on the geometrical configuration of adsorption. We find that the stability of the Be/bilayer system increases with the size of the beryllium clusters inserted into the bilayer of graphite. We also find a charge transfer from beryllium to the graphite layers. All these results are analysed in terms of electronic structure.

Interaction of beryllium containing plasma with ITER materials

Beryllium-seeded deuterium plasma is used in PISCES-B to investigate mixed-material erosion and redeposition properties of ITER relevant divertor materials. The beryllium containing plasma simulates the erosion of first wall material into the ITER sol plasma and its subsequent flow towards the carbon divertor plates. The experiments are designed to quantify the behaviour of plasma created mixed Be/C and Be/W surfaces. Developing an understanding of the mixed material surface behaviour is crucial to accurately predict the tritium accumulation rate within the ITER vacuum vessel. The temporal evolution of the plasma interactions with the various mixed surfaces are examined to better understand the fundamental mechanisms in play at the surface and to allow scaling of these results to the conditions expected in the ITER divertor. A new periodic heat pulse deposition system is also installed on PISCES-B to simulate the transient temperature excursions of surfaces expected to occur in the ITER divertor during edge localized modes (ELMs) and other off-normal events. These periodically applied heat pulses allow us to study the effects of transient power loading on the formation, stability and tritium content of mixed-material surfaces that are created during the experiments.

Oxidation of beryllium—a scanning Auger investigation

Beryllium is considered to be a candidate material for the first wall of nuclear fusion plasma experiments, e.g. ITER. In this application, the interaction of beryllium with oxygen is important for two reasons. One aspect is the reaction of hot beryllium with air in case of a catastrophic leak, the other is the action of beryllium as a getter, binding oxygen impurities and thus helping to keep the level of contamination in the plasma low. We therefore investigated the interaction of beryllium with air at elevated temperatures up to 600°C on a microscopic level, using a high resolution Auger electron microscope. At 390°C, a thin protective oxide film is formed, while at 500°C oxidation starts to enter into the grain boundaries, leading to the loosening of small particles of beryllium already at 600°C. The expected diffusion of oxygen from the surface into the bulk has not been observed up to 390°C, the highest temperature to be safely applied inside the Auger microscope. Exposure to hydrogen atmosphere showed no change up to 600°C, exposure to hydrogen plasma resulted in an equilibrium thickness of the oxide layer, which is most likely due to impurities in the plasma. Thus, an operation of beryllium liners as a non-evaporable getter is not to be expected in this temperature range. Getter activity linked to the transport of beryllium from the liner to some deposition areas is, however, possible.

Formation of a surface alloy in the beryllium–tungsten system

The interaction of beryllium and tungsten is investigated by deposition of thin beryllium layers (several nanometers) from the vapor phase onto polycrystalline tungsten substrates and analysis by means of X-ray photoelectron spectroscopy (XPS). Already after room temperature deposition we observe formation of a surface alloy, limited to the interface between the layer and the substrate. The alloy intensity increases continuously between 670K and 1070K. The alloy formation is restricted to a depth of 1.2nm in maximum. Be in excess to this layer thickness desorbs from the sample surface. No Be diffusion or dissolution in the W bulk is observed. Sputter depth profiles before and after annealing experiments in combination with TRIDYN calculations demonstrate that Be is limited to the near-surface area of the tungsten substrate.

Potential binding modes of beryllium with the class II major histocompatibility complex HLA-DP: a combined theoretical and structural database study

In an effort to understand the molecular basis of chronic beryllium disease (CBD), a study of the chemical relationship between beryllium, antigen, and the major histocompatibility complex II, HLA-DP, was undertaken. A homology model of the HLA-DP protein was developed. An analysis of the sequences of HLA-DPB1 and HLA-DPA1 alleles most common among CBD patients revealed several carboxylate rich regions in the peptide-binding cleft. These regions contain many hard Lewis base sites that may provide bonding opportunities for beryllium, a hard Lewis acid. Quantum chemistry calculations and structural database results support the presence of beryllium clusters, bridged by carboxylate, hydroxo, and/or oxo ligands, in the HLA-DP binding cleft. These results strongly suggest that beryllium clusters are an integral part of the antigen, and may even act solely as antigen. This work provides an initial model for thinking about beryllium interactions with proteins relevant to CBD and other metal-induced diseases.

Interaction of beryllium(II) in aqueous solution with bidentate ligands containing phosphonate groups

The complexes formed by beryllium(II) with ligands derived from phosphonoacetic acid (H 3pa) and methylenediphosphonic acid (H 4mdp) have been investigated in aqueous solution using both potentiometric and multinuclear magnetic resonance measurements. The protonation constants of the two ligands were determined at 298 K at ionic strength 0.5 mol dm −3 made up with NaClO 4 and [(CH 3) 4N]Cl. Seven phosphonoacetate complexes [Be(pa)] −, [Be(pa) 2] 4−, [Be(Hpa)], [Be(Hpa)(pa)] 3−, [Be(Hpa) 2] 2−, [Be 3(OH) 3(pa)] and [Be 3(OH) 3(pa) 3] 6− and seven methylenediphosphonate complexes, [Be(mdp)] 2−, [Be(mdp) 2] 6−, [Be(Hmdp)] −, [Be(H 2mdp)], [Be(Hmdp)(mdp)] 5−, [Be(Hmdp) 2] 4− and [Be(H 2mdp)] 2−, have been assumed to be present as major complex species. The corresponding formation constants were determined at 25°C at ionic strength 0.5 mol dm −3 (NaClO 4). In general, mdp complexes are more stable than the pa complexes having comparable stoichiometry. Phosphonate is able to displace water from [Be(H 2O) 4] 2+ without the assistance of a chelate effect, even at very low pH values. The complexes [BeL 2] n− ,(L = pa, n = 4; L = mdp, n = 6), are the most predominant species at physiological pH values; the mdp derivative is more stable than the pa one which, in turn, is much more stable than the corresponding malonate complex. The complex K 2[Be(H 2mdp) 2]·2H 2O was isolated in the solid state from reaction of Be(OH) 2 with H 4mdp and KOH, in aqueous solution, at pH 2.60 and its composition has been confirmed through ESMS spectra.

Studies of tritium desorption from beryllium and characterization of erosion products under plasma–beryllium interaction

The paper describes results of two studies related to the use of beryllium as plasma facing material in fusion reactors. The first study is devoted to the burst release of tritium and helium from neutron irradiated beryllium under high heating rates (up to 100 K s −1), and to reduction of temperatures corresponding to the gas release peaks with growth of the heating rates as well as to mechanisms of the above mentioned phenomena. Experiments were accompanied with theoretical estimates. Beryllium sputtering under hydrogen ion bombardment was under the second study. The microstructure of beryllium surfaces and redeposited films were investigated. Thickness of the redeposited film, sizes of erosion products, and hydrogen accumulation in it were measured.

Preparative, potentiometric and NMR studies of the interaction of beryllium(II) with oxalate and malonate. X-ray structure of K 3[Be 3(OH) 3(O 2C–CH 2–CO 2) 3]·6H 2O

The complexes formed by beryllium(II) with the bidentate ligands oxalate, L=(O 2C–CO 2) 2−, and malonate, L=(O 2C–CH 2–CO 2) 2−, have been investigated in aqueous solution using both potentiometric and 9Be NMR measurements. The species [BeL(H 2O) 2], [BeL 2] 2−, [Be 3(OH) 3L 3] 3− and [Be 3(OH) 3(H 2O) 3L] + have been identified and their formation constants have been determined at 25°C in 0.5 mol dm −3 NaClO 4. The malonate complexes are much more stable than the oxalate ones. New crystalline salts of formula K 3[Be 3(OH) 3L 3]· nH 2O have been isolated using conditions established with the aid of speciation calculations. The structure of K 3[Be 3(OH) 3(malonate) 3]·6H 2O has been determined by an X-ray structure analysis: orthorhombic, space group Pc2 1 n, a=9.011(3), b=14.041(4), c=18.761(9) Å, Z=4. Each beryllium atom is tetrahedrally coordinated by two hydroxo groups and two oxygen atoms from the chelating malonate. The (Be(OH)) 3 core is a puckered six-membered ring with each hydroxo group bridging two beryllium centres.

Compatibility of stainless steels and lithium based ceramics with beryllium

Abstract The introduction of beryllium as a neutron multiplier in ceramic blankets of thermonuclear fusion reactors may give rise to the following compatibility problems: (i) oxidation of Be by ceramics (lithium aluminate and silicates) or by water vapour; (ii) interaction between beryllium and austenitic and martensitic steels. The studies were done in contact tests under vacuum and in tests under wet sweeping helium. The contact tests under vacuum have revealed that the interaction of beryllium with ceramics seems to be low up to 700°C, the interaction of beryllium with steels is significant and is characterized by the formation of a diffusion layer and of a brittle Be-Fe-Ni compound. With type 316 L austenitic steel, this interaction appears quite large at 600°C whereas it is noticeable only at 700°C with martensitic steels. The experiments carried out with sweeping wet helium at 600°C have evidenced a slight oxidation of beryllium due to water vapour which can be enhanced in the front of uncompletely dehydrated ceramics.

Compatibility problems in tritium breeding blankets

The compatibility between tritium breeding materials (liquid or solid), neutron multiplier and structural steels is a concern for the choice of a tritium breeding blanket for NET. For solid tritium breeding blanket, it seems that the more severe compatibility problem is due to the interaction of beryllium with steel. As for the water-cooled Pb17Li blanket, the first results obtained in experimental conditions closed to the concept have evidenced lower corrosion rates than those measured in thermal convection loops.

Formation mechanism and kinetics of non-aqueous fluorides of rare metals through interaction of their oxides with fluorine hydride

The study on kinetics and synthesis mechanism of non-aqueous fluorides of rare metals by interaction of their oxides with fluorine hydride has been carried out in polythermal and isothermal regimes in the range 425-875 K.The polythermal kinetic curves, obtained at a steady temperature rise of the sample, have been compared with the model equation, which were presented by several authors as tabulagrames. The comparison of that kind ensures reliable postulating for certain for reaction mechanism of an oxide and fluorine hydride interaction.Quantitative kinetic equations have been calculated pertaining to the interaction of beryllium,scandium, yttrium,lanthanum, gadolinium, erbium, zirconium, hafnium and thorium oxides with fluorine hydride in a wide range of temperature and concentrations.