[en] This document describes the purpose and execution of the Zircaloy spent fuel cladding electrochemical corrosion experiment at 170⁰C and approx.120 psia H₂O (liquid water present). The experimental sample materials and design are described as are the equipment, procedures and post-experiment sample evaluation

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[en] This document describes the purpose and execution of the electrochemical corrosion scoping experiments. The design of the spent fuel cladding bundles that represent the loaded canister in the repository environment is reviewed. The experimental procedures and post-experiment cladding evaluation are described in detail

[en] A potential dye sensitizer material for solar cell composed of a ruthenium-(4, 4'dimethyl-2, 2'-bipyridine)-isothiocyanato-tungsten-[bis-(phenyl-1, 2-ethilenodithiolenic)] bimetallic complex structure was successfully developed using Density Functional Theory (DFT) calculations. The optimal structure was realized by calculations using the generalized gradient approximation (GGA) framework in a double numeric plus polarization (DNP) basis set using the following three functional methods: Becke-Pardew (BP), Becke-Lee-Yang-Parr (BLYP) and Perdew-Burke-Ernzerhof (PBE). The PBE calculation gave a structure with bond lengths and angles that approximated the experimental data. The restricted-spin calculation of PBE found that BM has 339 molecular orbitals in which the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are located at orbital numbers 312 and 313, respectively. The HOMO was delocalized over the W(S₂C₂) ring, the ruthenium metal center and the thiocyanate bridging ligand. In contrast, the LUMO was found mainly at the bipyridyl ligand with a small contribution from the ruthenium metal center. Electron excitation from the HOMO→LUMO occurred at 2964 nm with an excitation energy of 0.42 eV, which is depicted by the charge transfer from one metal to another (intervalence charge transfer, IVCT) or as a manifestation of the NCS bridging ligand. (author)

[en] The terms of electrochemical corrosion are defined, EC is generally a type of corrosion in which electrochemical processes occur. It only takes course in the presence of an electrolyte. The corrosion need not be immediately caused by an electrolytic abrasion here, it can also be the result of reaction with an electrochemically produced intermediate product (e.g. atomic hydrogen). A characteristic feature of electrochemical corrosion is the dependence of the corrosion procedures on the electrode potential. (orig./LH)

[en] Corrosion rates of three types of welded 304 stainless steel specimens immersed in 1 N H₂SO₄ solution at room temperature were obtained from potentiodynamic polarization curves, Tafel plots and polarization resistance curves. Corrosion rate measurements by using AC impedance technique were also carried out in order to investigate whether these values agreed fairly well with the values obtained from other electrochemical techniques. Corrosion rates of welded specimens were increased with increasing frequency of GTAW and decreasing current density of GTAW. It was concluded that an A.C. impedance technique could be successfully utilized for determining a local corrosion rate of welded parts. (Author)

[en] Process for welding components such as fins on to parts like tubes which avoids the formation of a copper deposit on the tube that would encourage corrosion. Cuts are made through part of the width of a strip. This strip is folded along its length and then wrapped around the part to be fitted with fins. The uncut part of the strip is made to bear on the periphery of the part to form the foot of the fin so that the cut part fans open forming segmented fins. A wheel is pressed on to the foot of a fin and another wheel is likewise pressed on to the foot of another fin in contact with the tube to close the electric circuit to the generator, the wheels and the tube being actuated rotationally in relation to each other so that the heat, generated in each successive contact between the fin to be welded and tube, welds the fin to the tube

[en] To evaluate the effects of flow field on FAC, orifice flow was measured using LDV and simulated by LES. FAC rate was also measured in a test loop. The LDV measurements indicated the flow structure did not depend on the flow velocity. Flow field predicted by RANS and LES agreed well with LDV data. The metal loss increased linearly with time downstream from the orifice but gradually decreased upstream. FAC rate increased as velocity increased. FAC rate predicted by LES had a clear relationship with the predicted RMS of wall shear stress. (author)

[en] This paper presents the findings of the research properties evaluation pastes of commercial cement (CPC), mixed with fly ash (FA) and granulated blast furnace slag (GBFS). Initially, the sample of 30 combinations were evaluated in terms of compressive strength to establish the optimal proportions from raw material. After that, four optimized blends were characterized during the setting and hardening process. Electrochemical tests were performed on concrete cylinders samples prepared with cementitious materials and a structural steel rod placed in the center of the specimen. With the objective to evaluate the performance before corrosion, thermodynamic and kinetic aspects were taken into consideration. The findings showed that commercial cements blended with fly ash and blast furnace slag as the ones used in this research presents a decreased behavior in mechanical and corrosion strength regarding to CPC. (Author)

[en] This work presents briefly the current status of the electrochemical kinetics, with a particular stress on corrosion in a H₂O-H₂S environment. Experimental methods are described. On the basis of the obtained results a comparison is given concerning the performances and the limitations of the different working modalities. Depending on the specific method adopted ways of optimization are indicated