Impact of thermal and chemical treatment on the mechanical properties of E110 and E110G cladding tubes

M. Kir aly,Z. Hozer,M. Horvath,T. Novotny,E. Perez-Fero,N. Ver 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.2

The mechanical and corrosion behavior of the Russian zirconium fuel cladding alloy E110, predominantlyused in VVERs, has been investigated for many decades. The recent commercialization of a new, optimizedE110 alloy, produced on a sponge zirconium basis, gave the opportunity to compare the mechanicalproperties of the old and the new E110 fuel claddings. Axial and tangential tensile test experiments were performed with samples from both claddings in theMTA EK. Due to the anisotropy of the cladding tubes, the axial tensile strength was 10e15% higher thanthe tangential (measured by ring tensile tests). The tensile strength of the new E110G alloy was 11%higher than that of the E110 cladding at room temperature. Some samples underwent chemical treatment e slight oxidation in steam or hydrogenation e or heattreatment e in argon atmosphere at temperatures between 600 and 1000 C. The heat treatment duringthe oxidation had more significant effect on the tensile strength of the claddings than the oxidation itself,which lowered the tensile strength as the thickness of the metal decreased. The hydrogenation of thecladding samples slightly lowered the tensile strength and the samples but they remained ductile even atroom temperature.

OECD/NEA Sandia Fuel Project phase I: Benchmark of the ignition testing

Adorni, M.,Herranz, L.E.,Hollands, T.,Ahn, K.I.,Bals, C.,D'Auria, F.,Horvath, G.L.,Jaeckel, B.S.,Kim, H.C.,Lee, J.J.,Ogino, M.,Techy, Z.,Velazquez-Lozad, A.,Zigh, A.,Rehacek, R. North-Holland Pub. Co 2016 Nuclear engineering and design Vol.307 No.-

The OECD/NEA Sandia Fuel Project provided unique thermal-hydraulic experimental data associated with Spent Fuel Pool (SFP) complete drain down. The study conducted at Sandia National Laboratories (SNL) was successfully completed (July 2009 to February 2013). The accident conditions of interest for the SFP were simulated in a full scale prototypic fashion (electrically heated, prototypic assemblies in a prototypic SFP rack) so that the experimental results closely represent actual fuel assembly responses. A major impetus for this work was to facilitate severe accident code validation and to reduce modeling uncertainties within the codes. Phase I focused on axial heating and burn propagation in a single PWR 17x17 assembly (i.e. ''hot neighbors'' configuration). Phase II addressed axial and radial heating and zirconium fire propagation including effects of fuel rod ballooning in a 1x4 assembly configuration (i.e. single, hot center assembly and four, ''cooler neighbors''). This paper summarizes the comparative analysis regarding the final destructive ignition test of the phase I of the project. The objective of the benchmark is to evaluate and compare the predictive capabilities of computer codes concerning the ignition testing of PWR fuel assemblies. Nine institutions from eight different countries were involved in the benchmark calculations. The time to ignition and the maximum temperature are adequately captured by the calculations. It is believed that the benchmark constitutes an enlargement of the validation range for the codes to the conditions tested, thus enhancing the code applicability to other fuel assembly designs and configurations. The comparison of lumped parameter and CFD computer codes represents a further valuable achievement.

Relaxation issues in nanoindentation experiments

P.M. Nagy,P. Horvath,D. Aranyi,E. Kalman 한국물리학회 2006 Current Applied Physics Vol.6 No.2

ples and antimony doped SnO2 thin lms (ATO) by depth sensing indentation (nanoindentation) experiment. The combination ofnanoindentation and atomic force microscopy provides a straightforward method to follow the indentation and relaxation processof the material, revealing not only the hardness and Young.s modulus of the sample, but also gaining information on the deforma-tion process taking place during the indentation. A method was worked out based on computer evaluation of AFM images of nano-pyramid. It provides a quantitative method to investigate the relaxation characteristic of dierent materials. Single grains incoarse-grained titanium and the ATO layers were investigated by this combined method, anisotropy and relaxation eects were stud-ied. The hardness and Young.s modulus of the ATO layers have been found to be dependent on the preparation method, but therelaxation of various layers are largely uniform. Dierent Ti grains, however, have uniform hardness and Young.s modulus, but the relaxation effects in these samples show orientation dependence.

SURFACE ROUGHNESS EFFECTS ON THE COERCIVITY OF THIN FILM HEADS

Hyunkyu Kim,M. Pardavi Horvath 한국자기학회 1995 韓國磁氣學會誌 Vol.5 No.5

The domain wall motion coercivity, Hc, of magnetic materials arises from the dependence of the wall energy on localized changes in material parameters (magnetization, anisotropy, exchange energy densities). However, in an otherwise perfectly homogeneous material, the domain wall energy might change due to the change in the volume of the wall versus the wall position. Thus, any surface roughness contributes to the coercivity. Assuming different two-dimensional surface profiles, characterized by average wavelengths λx and λy, and relative thickness variations dh/h, the coercivity due to the surface roughness has been calculated. Compared to the one dimensional case, the 2D coercivity is reduced. Depending on the ratio of λ to the domain wall width, Hc has a maximum around 2, and increasing with dh/h. With the decreasing thickness of the thin film and GMR heads, it might be the domain factor in determining the coercivity.

Aqueous and non aqueous chemistry studies of high purity aluminum nitride powders

Martin P. Harmer,Frederick M. Fowkes,Stephen F. Horvath 한양대학교 세라믹연구소 2004 Journal of Ceramic Processing Research Vol.5 No.4

Tubular inorganic nanostructures

I. Kiricsi,D. Fudala,D. Mehn,A. Kukovecz,Z. Konya,M. Hodos,E. Horvath,M. Urban,T. Kanyo,E. Molnar,R. Smajda 한국물리학회 2006 Current Applied Physics Vol.6 No.2

Tubular inorganic nanostructures are high aspect ratio nanomaterials possessing few nanometer wide inner channels. We reporton our studies about engineering the chemical composition, morphology and pore size of carbon, silica and titania nanotubes as wellas of mesoporous silicate MCM-41. The former three systems represent three dierent classes of inorganic nanotubes, since theyexhibit superior catalyst support properties as well.

실행 요약: 당뇨병의 진단과 관리에서 검사실적 분석에 대한 지침과 권고안

David B. Sacks,Mark Arnold,George L. Bakris,David E. Bruns,Andrea Rita Horvath,M. Sue Kirkman,Ake Lernmark,Boyd E. Metzger,David M. Nathan 대한진단검사의학회 2011 Laboratory Medicine Online Vol.1 No.4

Background: Multiple laboratory tests are used in the diagnosis and management of patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially. Approach: An expert committee compiled evidencebased recommendations for the use of laboratory analysis in patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. A draft of the guidelines was posted on the Internet, and the document was modified in response to comments. The guidelines were reviewed by the joint Evidence-Based Laboratory Medicine Committee of the AACC and the National Academy of Clinical Biochemistry and were accepted after revisions by the Professional Practice Committee and subsequent approval by the Executive Committee of the American Diabetes Association. Content: In addition to the long-standing criteria based on measurement of venous plasma glucose, diabetes can be diagnosed by demonstrating increased hemoglobin A1c (HbA1c) concentrations in the blood. Monitoring of glycemic control is performed by the patients measuring their own plasma or blood glucose with meters and by laboratory analysis of Hb A1c. The potential roles of noninvasive glucose monitoring, genetic testing,and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed. Summary: The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are found to have minimal clinical value at the present time, and measurement of them is not recommended.