Showing papers by "U. Kamachi Mudali published in 2017"
TL;DR: In this article, the corrosion behavior of TaNbHfZrTi high-entropy alloy (HEA) was investigated in nitric and fluorinated nitric acid at ambient (27°C) and boiling (120 °C) conditions.
58 citations
TL;DR: In this paper, the behavior of fly ash concrete exposed to sea water environments was investigated and a holistic idea about the behaviour of fly-ash concrete was obtained. But, the results of the experiment were limited to 280 days of exposure.
Abstract: The objective of this work was to get a holistic idea about the behavior of fly ash concrete exposed to sea water environments. Concrete mixes namely Normal Concrete (NC), concrete with fly ash and superplasticizer (FA) and concrete with superplasticizer alone (SP) were cast and immersed for a year to find out the strength, durability, biofilms formation and chemical composition. The pH, compressive strength, Half Cell Potential (HCP), Rapid Chloride Permeability Test (RCPT) and carbonation test showed better results in FA. Epifluorescence micrograph observed less number of fluorescing cells. Analysis of phase images of Lock- in thermography reveals the phase angle differences of concrete samples indicating the least deterioration on FA concrete. After 280 days of exposure, XRD showed higher loss of calcium elements in NC and SP concrete compared to FA. LRS also showed that Raman intensities of NC and SP were drastically reduced. However, LRS and XRD results of FA confirmed formation of more cementitious products due to secondary hydration explaining the reason for increased compressive strength.
27 citations
TL;DR: In this paper, the authors established the mechanism of this reaction under typical PUREX process conditions based on the concentration profiles of nitric and nitrous acids and NO X gas composition during the course of dissolution of sintered UO2 pellets in nitric acid.
Abstract: The mechanism of dissolution of sintered UO2 fuel pellets in nitric acid is the essential starting input information required for the design of a continuous dissolution system for spent nuclear fuel reprocessing. The current article establishes the mechanism of this reaction under typical PUREX process conditions based on the concentration profiles of nitric & nitrous acids and NO
X
gas composition during the course of dissolution of sintered UO2 pellets in nitric acid. The results would be useful in optimizing the dissolution process and improving the throughput of the dissolution system.
23 citations
TL;DR: The insulation resistance of conventional atmospheric plasma-sprayed alumina coatings with 10-15% porosity is ∼1011 Ω as mentioned in this paper, and the presence of pores, lamellae boundaries, and other non-fillings dampens the insulation.
Abstract: The insulation resistance of conventional atmospheric plasma-sprayed alumina coatings with 10–15% porosity is ∼1011 Ω. The presence of pores, lamellae boundaries, and other non-fillings dampens the...
18 citations
TL;DR: In this article, superhydrophobic (SHP) coatings on titanium were developed using a two-step method involving anodization and coating with silane and the robustness of the SHP coatings was assessed by sonication and water impact tests.
Abstract: Superhydrophobic (SHP) coatings on titanium were developed using a two-step method involving anodization and coating with silane The robustness of the SHP coatings was assessed by sonication and water impact tests The adhesion of the coatings was evaluated by ASTM standard tape test After evaluating the stability, the durability of superhydrophobic coatings developed on titanium was tested in seawater The long-term immersion in seawater showed minimal reduction in water contact angle (WCA) after the immersion Antibacterial activity of the SHP coatings after long-term exposure in seawater and bacterial pure cultures were also evaluated The present study aims to evaluate the stability, durability and shelf life of the SHP coatings developed on Ti using silanes for long-term practical applications
16 citations
TL;DR: In this article, self-assembled TiO2 nanopore arrays (TNPA) were developed by electrochemical anodization and microscopic studies revealed the presence of nanoporous surface with pore diameter and length of about 84 and 100 nm, respectively.
Abstract: Self-assembled TiO2 nanopore arrays (TNPA) were developed by electrochemical anodization. Microscopic studies revealed the presence of nanoporous surface with pore diameter and length of about 84 and 100 nm, respectively. Growth of apatite (HAp) on TNPA after immersion in Hank’s solution for different durations such as 3, 5, and 7 days was confirmed by various spectroscopic studies. Polarization study exhibited that the specimens after immersion in Hank’s solution showed high corrosion resistance which is attributed to the HAp growth on TNPA surface. Hence, TNPA is a viable material with required biocompatibility and corrosion resistance for use as orthopedic implants.
13 citations
31 Jul 2017-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this article, the effect of laser surface melting (LSM) on the microstructural variations and pitting corrosion resistance of 304L SS weldment fabricated by gas tungsten arc welding was presented.
Abstract: The manuscript presents the effect of laser surface melting (LSM) on the microstructural variations and pitting corrosion resistance of 304L SS weldment fabricated by gas tungsten arc welding of 304L SS plates using 308L SS filler wire. The weld region was examined by X-ray radiography for defect detection. LSM of 304L SS weldment was performed using Nd:YAG pulsed laser. Microstructural evaluation was carried out using optical and electron back scatter diffraction techniques. The microstructure of 304L SS base was found to be austenitic, while the weld region of 304L SS weldment contained delta ferrite distributed in austenite matrix. The microstructure of LSM 304L SS weldment was found to be homogeneous austenite matrix with sparsely distributed ferrite. Ferrite measurements showed a decrease in the percentage ferrite in the fusion zone of 304L SS weldment after LSM. A profound enhancement in the pitting corrosion resistance was observed after LSM, which could be attributed to the homogeneous microstructure and decrease in the ferrite content. Pit density was found to be higher in the heat-affected zone of the weldment. Very few pits were observed in the LSM 304L SS weldment compared to the as-weldment.
11 citations
TL;DR: In this article, experiments were conducted for U(VI) extraction from simulated highly-active feed with 30% TBP/n-dodecane (PUREX solvent) and 36% TiAP/N-dodaane (alternate PUREX solvent), at demanding residence times of typically 0.25
Abstract: Kinetics of U(VI) extraction, in centrifugal flow-field under PUREX conditions, is reported to be quite fast with a time constant of about 2–5 s. To test the limits of extraction under micro-mixing conditions, experiments were conducted for U(VI) extraction from simulated highly-active feed with 30% TBP/n-dodecane (PUREX solvent) and 36% TiAP/n-dodecane (alternate PUREX solvent) solutions in a micromixer-settler at demanding residence times of typically 0.25 s. Although employed residence times for mixing were fractions of time constants, reported in the literature, a quantitative extraction (and back extraction) was observed as indicated by excellent recoveries of U(VI) in the experiments.
11 citations
TL;DR: In this paper, an experimental study has been taken up to assess the compatibility of few candidate materials for sacrificial layer, with liquid sodium at high temperature conditions, based on literature, alumina and Yttria Stabilized Zirconia (YSZ) are chosen due to their favorable properties like high melting point and lower thermal conductivity.
11 citations
TL;DR: In this paper, two ceramic coatings were investigated for its application as a layer of sacrificial material on the top of core catcher to enhance its capability, and they were tested for their suitability as thermal barrier layer for core catcher.
Abstract: Currently, stainless steel grade 316LN is the material of construction widely used for core catcher of sodium-cooled fast reactors. Design philosophy for core catcher demands its capability to withstand corium loading from whole core melt accidents. Towards this, two ceramic coatings were investigated for its application as a layer of sacrificial material on the top of core catcher to enhance its capability. Plasma-sprayed thermal barrier layer of alumina and partially stabilised zirconia (PSZ) with an intermediate bond coat of NiCrAlY are selected as candidate material and deposited over 316LN SS substrates and were tested for their suitability as thermal barrier layer for core catcher. Coated specimens were exposed to high-temperature thermite melt to simulate impingement of molten corium. Sodium compatibility of alumina and PSZ coatings were also investigated by exposing samples to molten sodium at 400 °C for 500 h. The surface morphology of high-temperature thermite melt-exposed samples and sodium-exposed samples was examined using scanning electron microscope. Phase identification of the exposed samples was carried out by x-ray diffraction technique. Observation from sodium exposure tests indicated that alumina coating offers better protection compared to PSZ coating. However, PSZ coating provided better protection against high-temperature melt exposure, as confirmed during thermite melt exposure test.
10 citations
TL;DR: In this paper, an attempt was made to explore the electrochemical behavior of Titanium (Ti) condenser material under seawater biofilms, which was subjected to microscopic examinations and electrochemical studies such as cyclic voltammetry (CV), electrochemical impedance spectroscopy, open circuit potential monitoring and anodic polarization.
Abstract: An attempt was made to explore the electrochemical behavior of Titanium (Ti) condenser material under seawater biofilms. The Ti specimens with seawater biofilm were subjected to microscopic examinations and electrochemical studies such as cyclic voltammetry (CV), electrochemical impedance spectroscopy, open circuit potential monitoring and anodic polarization. The CV curves of Ti specimens with 15 days old biofilms showed characteristic redox peaks with high cathodic current indicating the electroactive biofilms. Similarly impedance spectra clearly showed two time constants with decrease in charge transfer resistance and increase in capacitance as the biofilms growth increased on the Ti specimens. Polarization curve showed the ennoblement of corrosion potential and increase in passive current with the growth of biofilm on Ti. Based on these data, a possibility of Ti passive film integrity loss by electroactive seawater biofilms has been discussed.
TL;DR: In this article, the authors measured properties such as density, viscosity, interfacial tension (IFT) and phase disengagement time (PDT) after subjecting tri-iso-amyl phosphate (TiAP)-based solvent.
Abstract: Physiochemical properties such as density, viscosity, interfacial tension (IFT) and phase disengagement time (PDT) were measured after subjecting tri-iso-amyl phosphate (TiAP)-based solvent...
TL;DR: In this article, shot noise and wavelet analysis were used to analyze three austenitic stainless steels (SSs) with different molybdenum contents, including 304LN, 316LN and 317LN. The results showed that the total number of current transients, as well as transients with high current amplitude, decreased with increase in Mo content indicating increased resistance to pitting corrosion.
Abstract: Electrochemical noise (EN) studies were conducted on three austenitic stainless steels (SSs) with different molybdenum contents, 0.02 wt% Mo (Type 304LN SS), 2.53 wt% Mo (Type 316LN SS), and 3.58 wt% Mo (Type 317LN SS), in 0.01 M FeCl3 solution at the corrosion potential (Ecorr) and at a sampling frequency of 1 Hz. The EN data were analyzed using shot noise and wavelet analysis techniques. Current transient analysis showed that the total number of current transients, as well as transients with high current amplitude, decreased with increase in Mo content indicating increased resistance to pitting corrosion. Shot noise analysis revealed higher normalized characteristic charge (q)N at low frequency in Type 304LN SS as compared to Type 316LN SS and Type 317LN SS, implying increase in pitting corrosion resulting from the absence of Mo in this steel. Pit current decreased substantially with increase in Mo content. These results were supported by the standard deviation of partial signal (SDPS) values generated ...
TL;DR: In this paper, 8-9% yttria-stabilized zirconia (YSZ) ceramic coating was applied on 9Cr-1Mo steel by atmospheric plasma spray process.
Abstract: For the electrorefining step in the pyrochemical reprocessing of spent metallic fuels of future sodium cooled fast breeder reactors, 9Cr-1Mo steel has been proposed as the container material. The electrorefining process is carried out using 5-6 wt.% UCl3 in LiCl-KCl molten salt as the electrolyte at 500 °C under argon atmosphere. In the present study, to protect the container vessel from hot corrosion by the molten salt, 8-9% yttria-stabilized zirconia (YSZ) ceramic coating was deposited on 9Cr-1Mo steel by atmospheric plasma spray process. The hot corrosion behavior of YSZ-coated 9Cr-1Mo steel specimen was investigated in molten UCl3-LiCl-KCl salt at 600 °C for 100-, 500-, 1000- and 2000-h duration. The results revealed that the weight change in the YSZ-coated specimen was insignificant even after exposure to molten salt for 2000 h, and delamination of coating did not occur. SEM examination showed the lamellar morphology of the YSZ coating after the corrosion test with occluded molten salt. The XRD analysis confirmed the presence of tetragonal and cubic phases of ZrO2, without any phase change. Formation of UO2 in some regions of the samples was evident from XRD results.
TL;DR: In this article, the oxidation behavior of Ni 60 Nb 30 Ta 10 metallic glass in air was investigated below its glass transition temperature (665°C), and the oxidation kinetics followed two-stage parabolic rate law at 450 and 550°C.
TL;DR: In this paper, the effect of carbonate precursors on the capacitive storage performance of MnCO 3 was investigated using powder X-ray diffraction (PXRD), infra-red spectroscopy (IR), surface area analysis, scanning and transmission electron microscopic techniques.
TL;DR: In this article, the authors present the methodology used for manufacturing the Zircaloy-4 tubes required for the dissolver assembly and the evolution of the microstructure at different stages of different stages.
Abstract: This paper presents the methodology used for manufacturing the Zircaloy-4 tubes required for the Zircaloy-4 mock-up dissolver assembly. The evolution of the microstructure at different stages of pr...
01 Jan 2017
TL;DR: In this paper, issues of material selection, fabrication, testing and evaluation, corrosion protection methodologies, including coatings, surface modification, corrosion monitoring of major components employed for liquid sodium, steam water, seawater, nitric acid, and molten chloride environments employed in nuclear industry will be briefly addressed in a coherent manner.
Abstract: The ever-increasing temperature, pressure, stresses, and aggressive environments of the industrial processes demand efficient materials and advanced manufacturing technologies for good performance and prolonged service of the component. Corrosion is one of the major degradation mechanisms by which materials used in the industries fail prematurely and result in significant economic losses. The science of corrosion prevention and control is highly complex in hostile environments, influenced by the fact that corrosion manifests in many forms and is affected by numerous factors, including microstructure, composition, environment, temperature, radiation, pressure, etc. Selecting appropriate material for the hostile environment is the first step in avoiding corrosion at an early stage of service. Fabrication of components from the chosen material without any deviation from design, distortion, defects, and heterogeneous microstructures is the next step in saving the components from undergoing corrosion issues during operation. During service and operation maneuvers, impurities and contamination or malfunctioning of components can lead to initiation and propagation of corrosion processes, shortening the useful service life of the components. Finally, the aging and limitation of the material due to environmental conditions of the operating plant limit the performance. In this chapter issues of material selection, fabrication, testing and evaluation, corrosion protection methodologies, including coatings, surface modification, corrosion monitoring of major components employed for liquid sodium, steam water, seawater, nitric acid, and molten chloride environments employed in nuclear industry will be briefly addressed in a coherent manner. The mechanism and type of corrosion will be briefly explained followed by protection method adopted for the various environments, and the critical issues and insight into the material-environment combination will be addressed. The choice of various materials like Cr-Mo steels, stainless steels, nickel alloys, titanium and zirconium and their alloys, as well as various types of coatings like thermal barrier coatings, double oxide coatings and mixed oxide coatings, superhydrophobic coatings, self-healing repair coatings, and antifouling coatings, will be explained based on their application for various hostile environments.
TL;DR: In this article, the sensitization behavior of Type 316LN stainless steel (SS) with varying nitrogen content in 0% to 25% cold worked (CW) as well as in the as-received condition was evaluated.
Abstract: The sensitization behavior of Type 316LN stainless steel (SS) with varying nitrogen content (007 wt% and 022 wt%) in 0% to 25% cold worked (CW) as well as in the as-received condition was evaluated Time-temperature-sensitization diagrams were established for the cold worked Type 316LN SS (nitrogen content: 007 wt% and 022 wt%), using ASTM A262 Practice-E test The time required for sensitization (ts) was found to decrease and critical cooling rates (CCR) increased up to 10% CW in the alloy with 007 wt% N At higher CW, ts increased and CCR decreased Similarly, ts decreased and CCR increased up to 15% CW in the alloy with 022 wt% N and at higher CW, ts increased and CCR decreased To understand the sensitization behavior of Type 316LN SS with varying nitrogen content during thermal aging at 923 K for various durations, nondestructive electrochemical techniques like double loop electrochemical potentiokinetic reactivation (DL-EPR) technique and electrochemical reactivation technique (ERT) were adopt
TL;DR: In this article, a simulation of a distillation column for the separation of tributyl phosphate (TBP) and normal paraffin hydrocarbon (NPH) is presented.
TL;DR: In this article, a study on modified 9Cr-1Mo steel was carried out to understand its corrosion as well as passive film characteristics in caustic environment and the results showed increased corrosion attack during passivation with increase in concentration of alkali and temperature.
Abstract: Studies were carried out on modified 9Cr–1Mo steel to understand its corrosion as well as passive film characteristics in caustic environment. Potentiodynamic anodic polarization studies were carried out in 1–8 M sodium hydroxide solutions at room temperature (RT) and in boiling conditions. The specimens were passivated at 0.0 V(SCE) for 1 h in 3 and 8 M sodium hydroxide solutions at RT as well as in boiling condition. Laser Raman spectroscopic (LRS) analysis was carried out to examine the nature of oxides/hydroxides formed on the surface of the specimens. Corrosion rates increased by one order of magnitude whereas passive current density increased by almost two orders of magnitude in boiling solution compared to the RT values. Appearance of only maghemite (γ-Fe2O3) peaks in passivated steel in 3 M sodium hydroxide solution at RT compared to that in the 8 M sodium hydroxide solution, which showed Fe(OH)2, maghemite, magnetite, goethite (α-FeOOH) and CrO(OH), Cr2O3 peaks, indicated corrosion attack on the outer layer of the passive film. The passivated steel specimens in 3 and 8 M boiling solutions showed maghemite, magnetite, goethite, hematite (α-Fe2O3) (only in 8 M) and extremely weak peaks of Cr(OH)3 and Cr2O5. These observations indicated dissolution of the outermost part of the passive film with superficial attack on the inner part of the passive film exposing Cr oxide/hydroxides in boiling 3 M solution. However, passivated steel in 8 M solution showed molybdenum oxides, apart from the other iron and chromium oxides/oxyhydroxides. The scanning electron microscopic (SEM) studies on the morphology of the corrosion products along with LRS analysis/characterization confirmed these observations. These results showed increased corrosion attack during passivation with increase in concentration of alkali and temperature.
23 May 2017
TL;DR: The phase transition induced by severe plastic deformation (SPD) was confirmed in metastable AISI type 304L austenitic stainless steel (SS) SPD via cryo-rolling in liquid nitrogen (L-N2) temperature is the adopted route for correlating the phase transition and corrosion resistance as discussed by the authors.
Abstract: The phase transition induced by Severe Plastic Deformation (SPD) was confirmed in metastable AISI type 304L austenitic stainless steel (SS) SPD via cryo-rolling in liquid nitrogen (L-N2) temperature is the adopted route for correlating the phase transition and corrosion resistance The thickness of the annealed AISI type 304L SS at 1050°C sheet was reduced step by step from 15% to 50% of its initial thickness The phase changes and phase transformation are qualitatively analyzed by X-Ray Diffraction (XRD) method During the process, the XRD of each Cryo-Rolled and annealed sample was analyzed and different phases and phase transitions are measured The investigated AISI type 304L SS by SPD reveals a microstructure of γ-austenite; α’-marternsite and e-martensite formation depending on the percentage of cryo-rolling The Vickers hardness (HV) of the samples is also measured The corrosion rate of the annealed sheet and cryo rolled sample was estimated in boiling nitric acid as per ASTM A-262 practice-C testThe phase transition induced by Severe Plastic Deformation (SPD) was confirmed in metastable AISI type 304L austenitic stainless steel (SS) SPD via cryo-rolling in liquid nitrogen (L-N2) temperature is the adopted route for correlating the phase transition and corrosion resistance The thickness of the annealed AISI type 304L SS at 1050°C sheet was reduced step by step from 15% to 50% of its initial thickness The phase changes and phase transformation are qualitatively analyzed by X-Ray Diffraction (XRD) method During the process, the XRD of each Cryo-Rolled and annealed sample was analyzed and different phases and phase transitions are measured The investigated AISI type 304L SS by SPD reveals a microstructure of γ-austenite; α’-marternsite and e-martensite formation depending on the percentage of cryo-rolling The Vickers hardness (HV) of the samples is also measured The corrosion rate of the annealed sheet and cryo rolled sample was estimated in boiling nitric acid as per ASTM A-262 practice-C test
TL;DR: In this paper, the authors measured the activation energy of viscous flow in binary mixtures of polyethylene glycol-1000 (PEG-1000) and water in the temperature range 293.15-343.15 K at atmospheric pressure using a high precision viscometer.
Abstract: Abstract Viscosities of binary mixtures of polyethylene glycol-1000 (PEG-1000) and water were measured precisely in the temperature range 293.15–343.15 K at atmospheric pressure using a high precision viscometer. Viscosity data were used to calculate the activation energy of viscous flow. The activation energy was observed to increase with increase in the concentration of aqueous solutions of PEG which indicated that more energy is required to move the molecule inside the structure with increase in concentration. The measured data provided better understanding to explain the behaviour of macromolecules with respect to change in concentration and temperature. The results were discussed in the light of polymer-solvent interactions. At lower concentration range, the molecules exhibit weak interaction due to dominant repulsive force and at higher concentration the entanglement of polymer chain increases. In view of greater force of interaction between solute and solvent molecules forming hydrogen bonding, there will be an increase in interaction with temperature and concentration.
TL;DR: In this paper, 9Cr-1Mo steel with and without YSZ coating was evaluated in LiCl-KCl-UCl3 molten salt at 600 °C under argon atmosphere for various durations (100, 250, 500 and 1000 h).
Abstract: 9Cr–1Mo steel has been proposed as the container material for the electrorefining process of pyrochemical reprocessing of spent metallic fuels from the future sodium cooled fast breeder reactors. The electrorefining process was carried out using LiCl–KCl–UCl3 molten salt as the electrolyte at 500 °C under argon atmosphere. To protect the electrorefining vessel, made of 9Cr–1Mo steel from the attack by the electrolyte, yttria stabilized zirconia (YSZ) ceramic coating was deposited on 9Cr–1Mo steel by thermal spray process. The corrosion behavior of 9Cr–1Mo steel with and without YSZ coating was evaluated in LiCl–KCl–UCl3 molten salt at 600 °C under argon atmosphere for various durations (100, 250, 500 and 1000 h). The results revealed that with increase in exposure time, the weight loss of uncoated 9Cr–1Mo steel samples increased, while YSZ coated 9Cr–1Mo steel samples exhibited insignificant weight loss. SEM examination of exposed uncoated 9Cr–1Mo steel samples showed Cr depletion on the surface and formation of chromium based oxides as corrosion products. After the corrosion experiment, SEM/EDS and XRD analyses of both coated and uncoated samples showed the presence of Fe–Cr and UO2.
TL;DR: Pyrolytic graphite (PyG) as discussed by the authors is a highly oriented, dense and crystalline form of graphite, which exhibits superior air oxidation resistance, corrosion resistance, and favorable mechanical, thermal, and annealing properties.
Abstract: Pyrolytic graphite (PyG) is a highly oriented, dense and crystalline form of graphite, which exhibits superior air oxidation resistance, corrosion resistance, and favourable mechanical, thermal, an...
TL;DR: In this paper, the surface morphology and the chemical state of the oxide scales were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively.
Abstract: Modified 9Cr–1Mo steel was oxidized in air at 550 and 750 °C for 25, 100, 250 and 500 h and the oxide scales formed were analysed. The surface morphology and the chemical state of the oxide scales were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The different exposure temperatures and time showed significant variations on the surface morphologies, the nature of oxide scale, and oxide constituents. The energy dispersive X-ray spectroscopic (EDS) analysis revealed the segregation of Mn at 750 °C even for short exposure time. Grazing incidence X-ray diffraction (GIXRD) patterns revealed the scales to be enriched with haematite and less intense magnetite peaks. Detailed XPS characterization indicated the presence of mixed oxides of iron (Fe), chromium (Cr) and manganese (Mn) in the oxide scales. The Fe–Cr spinel in the oxide scale offered resistance to oxidation of the steel, whereas Mn–Cr spinel was deleterious in nature as it promoted cracking and formation of blisters.
TL;DR: In this article, a study of the dissolution behavior of the ferritic layer on SS 316LN samples formed by exposure to liquid sodium at 823 K was carried out by monitoring the H2 released during the chemical interaction with decontamination formulation.
Abstract: The Prototype Fast Breeder Reactor (PFBR) is nearing completion at Kalpakkam, India. Sodium is the heat transfer medium for PFBR, and austenitic steel SS 316LN is the material of construction for the sodium circuits of the reactor. During reactor service, the inner surfaces of the sodium circuit pipelines undergo corrosion by interacting with liquid sodium, forming ferritic layers. Radioactive nuclides formed by the activation of corrosion products are deposited on the ferritic surface, resulting in a radioactive burden on maintenance personnel. Chemical decontamination is generally carried out by dissolving the surface ferritic layer on the inside surface of the sodium circuit. In this context, a study of the dissolution behavior of the ferritic layer on SS 316LN samples formed by exposure to liquid sodium at 823 K was carried out by monitoring the H2 released during the chemical interaction with decontamination formulation. The decontamination chemical formulation was a mixture of sulfuric acid and phos...
TL;DR: In this paper, a hybrid self-assembled nanophase particle process (HSNAP) was used for the localized corrosion resistance of modified 9Cr-1Mo steel in 0.05 mM NaCl solution.
Abstract: Corrosion protection coatings were developed based on a hybrid self-assembled nanophase particle process (HSNAP) for the localized corrosion resistance of modified 9Cr–1Mo steel in 0.05 M NaCl solution. The coating sol was prepared using silane-zirconia precursors and a polymeric crosslinking agent. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to study the morphology and composition of the coated specimens, respectively. The thickness of the coatings was determined by a thickness gauge meter and Raman imaging analysis. The corrosion resistance of coated specimens was analyzed using electrochemical impedance spectroscopy, and it was observed that HSNAP-coated specimens showed superior resistance to localized corrosion than the as-received specimens in chloride medium.
11 Feb 2017
TL;DR: In this article, the authors investigated the feasibility of using gadolinium as soluble neutron poison for ensuring nuclear criticality safety during the processing of FBR spent fuel containing higher concentrations of fissile material.