Stainless Steel Container Research Articles

Corrosion of carbon steel components in the French high-level waste programme: evolution of disposal concept and selection of materials

ABSTRACTIn France, the reference concept for the geological disposal of high-level waste (HLW) consists of horizontal micro-tunnels, containing carbon steel casing and overpacks (around a stainless steel container containing vitrified waste). The overpacks and casing will be exposed to an environment that will evolve over time: from a hot and humid atmosphere containing oxygen, to an anoxic environment saturated with water at the geothermal temperature. Lots of corrosion experiments have been performed in representative environments to study steel corrosion modes (general corrosion, pitting and crevice corrosion, stress corrosion cracking, hydrogen embrittlement…) while taking into account the influence of temperature, radiation, mechanical stresses and microorganisms. Some key results have influenced the design of the HLW disposal cell, including the carbon steel grades and dimensions of the casing and overpacks, or the addition of an alkaline grout material between the casing and the host rock.This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems.

Thermal properties of simulated Hanford waste glasses

AbstractThe Hanford Tank Waste Treatment and Immobilization Plant will vitrify the mixed hazardous wastes generated from 45 years of plutonium production at the Hanford Site in Washington State. The molten glasses will be poured into stainless steel containers or canisters and subsequently cooled for storage and disposal. For appropriate facility design and operations to handle such highly energy‐consuming processes, knowledge of the material properties is required. The thermal properties (heat capacity, thermal diffusivity, and thermal conductivity) of representative high‐level and low‐activity waste glasses were studied as functions of temperature in the range of 200°C‐800°C (relevant to the cooling process). Simultaneous differential scanning calorimetry‐thermal gravimetry (DSC‐TGA), Xe‐flash diffusivity, pycnometry, and dilatometry were implemented. The study showed that simultaneous DSC‐TGA would be a reliable method for obtaining the heat capacity of various glasses in the temperature range of interest. Accurate thermal properties from this study were shown to provide a more realistic guideline for capacity and time constraints of the heat removal process when compared to the original conservative design‐basis engineering estimates. The estimates, though useful for design in the absence of measured physical properties, can now be supplanted and the measured thermal properties can be used in design verification activities.

Stress Corrosion Cracking on a Stainless Steel Container Triggered by the Ageing of a Polyurethane Insulation

Abstract A failure in the form of leakages caused by crack formation occurred after approximately 25 years of operationn on a type 1.4301 stainless steel container thermally insulated with polyurethane. From the appearance of the damages it was clear that the failure was caused by stress corrosion cracking. It was shown that chloride release by the ageing of the PU foam was responsible for the corrosion. The damages were documented via 3D digital microscopy and metallography. To avoid these kinds of damages, insulation materials free of halogen compounds should be used. Regular checks of old stainless steel reactors insulated with PU foam and operated at elevated temperatures are recommended.

Nanostructured ZnO films on stainless steel are highly safe and effective for antimicrobial applications.

The safety and effectiveness of antimicrobial ZnO films must be established for general applications. In this study, the antimicrobial activity, skin irritation, elution behavior, and mechanical properties of nanostructured ZnO films on stainless steel were evaluated. ZnO nanoparticle (NP) and ZnO nanowall (NW) structures were prepared with different surface roughnesses, wettability, and concentrations using an RF magnetron sputtering system. The thicknesses of ZnO NP and ZnO NW were approximately 300 and 620nm, respectively, and ZnO NW had two diffraction directions of [0002] and [01-10] based on high-resolution transmission electron microscopy. The ZnO NW structure demonstrated 99.9% antimicrobial inhibition against Escherichia coli, Staphylococcus aureus, and Penicillium funiculosum, and no skin irritation was detected using experimental rabbits. Approximately 27.2±3.0μgL-1 Zn ions were eluted from the ZnO NW film at 100°C for 24h, which satisfies the WHO guidelines for drinking water quality. Furthermore, the Vickers hardness and fracture toughness of ZnO NW films on stainless steel were enhanced by 11 and 14% compared to those of the parent stainless steel. Based on these results, ZnO NW films on STS316L sheets are useful for household supplies, such as water pipes, faucets, and stainless steel containers.

Influence of humidity on tribo-electric charging and segregation in shaken granular media.

We study the effect of humidity on the charge accumulation of polymer granulates shaken vertically in a stainless steel container. This setup allows us to control the humidity level from 5% to 100%RH while performing automated charge measurements in a Faraday cup directly connected to the shaking container. We find that samples of approximately 2000 polymer spheres become highly charged at low humidity levels (<30%RH), but acquire almost no charge for humidity levels above 80%RH. The transition between these two regimes does depend on the material, as does the sign of the charge. For the latter we find a correlation with the contact angle of the polymer with only very hydrophilic particles attaining positive charges. We show that this humidity dependence of tribo-charging can be used to control segregation in shaken binary mixtures.

옹기가 빵 품질에 미치는 영향

How do we use onggi, Korean earthenware, for container of dough during fermentation instead of stainless steel container? How does it affect the flavor of bread if onggi tray is used in baking instead of steel tray? We tried to confirm those. As a result, the characteristics of onggi made positive effect on dough in fermenting room. The time, when the temperature of the center in the dough is equilibrated to that of surface on the dough, take shorter in onggi than in stainless steel. It could make the temperature of dough maintained evenly with little deviation, which could result in shorter fermentation time. Volume and surface color of the bread baked on onggi tray were better than on steel tray. The bread baked on onggi tray got higher score on overall acceptability in sensory test than on steel tray. Therefore, if onggi is used during baking, it could produce better quality of bread like making positive effect on fermented foods.

Characterisation of Pinotage Wine During Maturation on Different Oak Products

The effect of oak contact on the phenolic composition, total antioxidant capacity (TAC) and colour of Pinotage wines was investigated during maturation. Oak maturation included traditional treatments, such as new, second-fill and third-fill barrels, as well as alternative treatments (oak chips, staves, extract and dust) applied in old barrels over a period of 28 weeks. Oak maturation using traditional and alternative treatments improved the objective colour of Pinotage wine by decreasing the L* value. Losses in TAC caused by decreased concentrations of monomeric phenolic compounds (most anthocyanins, flavan-3-ols, flavonols and hydroxycinnamic acids) during oak maturation were negated by increased concentrations of gallic acid and the formation of new oligomeric and polymeric pigments. Wine maturation in stainless steel containers also resulted in a decrease in anthocyanin content. The decrease in phenolic acid content for wines matured in stainless steel was less pronounced, while their flavan-3-ol content remained stable. The new-barrel treatment had the most pronounced effect on all parameters. Oak maturation can be used for the production of Pinotage wine when the retention of TAC is a high priority.

An approach to design a 90Sr radioisotope thermoelectric generator using analytical and Monte Carlo methods with ANSYS, COMSOL, and MCNP

In this study, a 90Sr radioisotope thermoelectric generator (RTG) with power of milliWatt was designed to operate in the determined temperature (300–312K). For this purpose, the combination of analytical and Monte Carlo methods with ANSYS and COMSOL software as well as the MCNP code was used. This designed RTG contains 90Sr as a radioisotope heat source (RHS) and 127 coupled thermoelectric modules (TEMs) based on bismuth telluride. Kapton (2.45mm in thickness) and Cryotherm sheets (0.78mm in thickness) were selected as the thermal insulators of the RHS, as well as a stainless steel container was used as a generator chamber. The initial design of the RHS geometry was performed according to the amount of radioactive material (strontium titanate) as well as the heat transfer calculations and mechanical strength considerations. According to the Monte Carlo simulation performed by the MCNP code, approximately 0.35 kCi of 90Sr is sufficient to generate heat power in the RHS. To determine the optimal design of the RTG, the distribution of temperature as well as the dissipated heat and input power to the module were calculated in different parts of the generator using the ANSYS software. Output voltage according to temperature distribution on TEM was calculated using COMSOL. Optimization of the dimension of the RHS and heat insulator was performed to adapt the average temperature of the hot plate of TEM to the determined hot temperature value. This designed RTG generates 8mW in power with an efficiency of 1%. This proposed approach of combination method can be used for the precise design of various types of RTGs.

Thermo-mechanical behaviour during encapsulation of glass in a steel vessel

Quantitative numerical simulations and qualitative evaluations are conducted to elucidate thermo-mechanical behaviour during pouring and solidification of molten glass into a stainless-steel cylindrical container. Residual stress and structural integrity in this casting/vitrification process is important because it can be used for long-term storage of high-level nuclear wastes. The predicted temperature and stress distributions in the glass and container agree well with previous measurements of the temperature histories and residual stresses. Three different thermal-stress models are developed using the finite-element method and compared. Two simple slice models were developed based on the generalized plane strain assumption as well as a detailed two-dimensional axi-symmetric model that adds elements according to the stages of pouring glass into the stainless steel container. The results reveal that mechanical interaction between the glass and the wall of the stainless steel container generates residual tensile stresses that approach the yield strength of the steel. Together, these results reveal important insights into the mechanism of stress generation in the process, the structural integrity of the product, and accuracy of the modelling-tool predictions.

A Small-scale Model to Assess the Risk of Leachables from Single-use Bioprocess Containers through Protein Quality Characterization.

Leachables from single-use systems often exist in small quantities and are difficult to detect with existing analytical methods. The presence of relevant detrimental leachables from single-use bioprocess containers (BPCs) can be indirectly detected by studying the stability of monoclonal antibodies via changes by size exclusion chromatography, capillary electrophoresis sodium dodecyl sulfate, and visible/sub-visible particles using a small-scale stress model containing high surface area-to-volume ratio at elevated temperature alongside with an appropriate control (e.g., glass vials or stainless steel containers). These changes in protein quality attributes allowed the evaluation of potential risks associated with adopting single-use bioprocess containers for storage as well as bag quality and bag differences between earlier and later batches. These leachables appear to be generated during the bag sterilization process by gamma irradiation. Improvements in protein stability after storage in "preheated" bags indicated that these leachables may be thermally unstable or volatile. The effect of surfactant levels, storage temperatures, surface area-to-volume ratios, filtration, and buffer exchange on leachables and protein stability were also assessed.

Tritium permeation characterization of Al2O3/FeAl coatings as tritium permeation barriers on 321 type stainless steel containers

Accurate tritium transport properties of prospective tritium permeation barriers (TPBs) are essential to tritium systems in fusion reactors. By passing a temperature and rate-controlled sweeping gas over specimen surfaces to carry the permeated tritium to an ion chamber, the gas-driven permeation of tritium has been performed on 321 type stainless steel containers with Al2O3/FeAl barriers, to determine the T-permeation resistant performance and mechanism of the barrier. The tritium permeability of the Al2O3/FeAl coated container was reduced by 3 orders of magnitude at 500–700 °C by contrast with that of the bare one, which meets the requirement of the tritium permeation reduction factor (PRF) of TPBs for tritium operating components in the CN-HCCB TBM. The Al2O3/FeAl barrier resists the tritium permeation by the diffusion in the bulk substrate at a limited number of defect sites with an effective area and thickness, suggesting that the TPB quality is a very important factor for efficient T-permeation resistance.

Assessing the Thermal Performance of Phase Change Material in a Photovoltaic/Thermal System

Photovoltaic/ thermal (PV/T) systems refer to systems which integrate photovoltaic and solar thermal technologies and have the added advantage of producing both electrical and thermal energy. This study has been carried out to experimentally investigate the application of phase change material (PCM) in a thermal system under the climatic conditions of Ireland. In this system, a stainless steel container of PCM was integrated with a PV panel. PCM absorbs heat generated by the PV during daylight hours. Water is piped through the PCM and absorbs heat stored by the PCM. The application of the PCM alone was found to regulate the temperature of the PV panel by approximately 5°C under climatic conditions of Ireland. This paper presents a method to assess the performance of a photovoltaic/thermal system with integrated PCM taking into account the useful heat energy gained by the water, stored by the PCM and the delay in available heat factor.

Introducing Donor Milk in a Neonatal Intensive Care Unit: A Developing Country's Perspective.

To replace 75% of formula feeds by donor human milk (DHM) feeds in the first three days of life in neonates admitted to the neonatal intensive care unit (NICU). It was a prospective observational study in the NICU in a resource-limited set up in India. All neonates admitted during December 2013 and August 2014, were included in the study without any exclusion. Expressed DHM was administered within 2-3h of manual expression without refrigeration or pasteurization. It was left standing at room temperature in a covered stainless steel container prior to use. Prospective entries of 2 hourly neonatal feeds, for first 3 d of life, (36 entries) were made in the charts. Main outcome was the desired percentage replacement of formula feeds. Total 168 neonates were admitted to the NICU over the study period. Their median [Interquartile range (IQR); Range] gestation and birth weight was 37 (36, 38; 24-42) wk and 2300 (2100, 2700; 500-2950) g respectively. A total of 4136/6027 (68.6%) charted feeds were of human milk and 1891(31.4%) were of formula milk. Thus, 68.6% of formula feeds were replaced by DHM. Neonates weighing ≤2kg were at a lower risk of getting >25% formula feeds. A simple low cost method was effective in replacing a significant proportion of formula feeds by DHM in the first three days of life for neonates in a resource poor set up.

Research on Energy Loss Distribution of an Augmented Railgun

In order to analyze the characteristics of energy loss distribution of the electromagnetic launcher (EML), a calculation model considering contact resistance, contact velocity skin effect, and friction force was established. First, a comparison between the calculation results and the experimental results was employed to verify the accuracy and the reliability of this model. Second, the energy loss of every component of the EML system was calculated and analyzed. Based on this model, the energy loss distribution is easily obtained and visually understood, which is helpful for the EML optimization design. Finally, we discussed the difference of the energy loss distribution between an augmented railgun with stainless steel containment and without containment. Results show that the stainless steel containment decreases the launch efficiency and make more electric energy transformed into resistance loss in the EML system.

ChemInform Abstract: On the Fluorination of Plutonium Dioxide by Ammonium Hydrogen Fluoride.

AbstractFollowing a literature survey on published PuF3 syntheses in view of its use within the fuel cycle of advanced molten salt fast nuclear reactors, the authors′ own method comprises fluorination of PuO2 with NH4HF2 (Ni crucible in stainless steel container, 350 °C, 24 h, 92% yield).

옹기가 빵 품질에 미치는 영향

How do we use onggi, Korean earthenware, for container of dough during fermentation instead of stainless steel container? How does it affect the flavor of bread if onggi tray is used in baking instead of steel tray? We tried to confirm those. As a result, the characteristics of onggi made positive effect on dough in fermenting room. The time, when the temperature of the center in the dough is equilibrated to that of surface on the dough, take shorter in onggi than in stainless steel. It could make the temperature of dough maintained evenly with little deviation, which could result in shorter fermentation time. Volume and surface color of the bread baked on onggi tray were better than on steel tray. The bread baked on onggi tray got higher score on overall acceptability in sensory test than on steel tray. Therefore, if onggi is used during baking, it could produce better quality of bread like making positive effect on fermented foods.

Effect of Annealing Time on the Formability of a Ultra Purified Ferritic Stainless Steel Containing Copper

For developing of a ultra-purified ferritic anti-bacterial stainless steel, 1.4 Cu % was added in 21% Cr ferritic stainless steel. The effect of annealing time on the formability was analyzed. The micro texture of steel was measured by using electron back scattering diffraction analysis. The Cu precipitates through different annealing periods were investigated by means of transmission electron microscopy. Average plastic strain ratio was calculated by the r values at 0, 45°and 90° directions measured by tensile testing. The results shows that with the extension of annealing time, the morphology of the Cu precipitates became into rod from spherical and the size increased. Average plastic strain ratio increased first and then decreased, while the change trend of anisotropy index was opposite. The higher formability is due to the {111} texture components increase significantly, while more {001}&lt;110&gt; component at 60 min was adverse for the formability. And anisotropy index was determined by γ components and {110}&lt;110&gt; components.

Corrosion behaviour of 304L stainless steel and 5754 aluminium alloy for intermediate‐level radioactive waste containers

300 series stainless steels are the most common materials used in the manufacture of container for the intermediate storage of low‐ and intermediate‐level radioactive wastes. Today, aluminium alloys are being considered as an alternative as they would enable gamma measurements to be performed directly through the container. However, reactions which occur during storage, lead to the formation of corrosive species. An investigation and comparison of the corrosion behaviour of a 5754 aluminium alloy container with that of a 304L stainless steel container was realised. Samples were introduced in corrosive environment during several months and then characterised by SEM. Results allow or not to validate the use of this aluminium alloy as nuclear container material.

Synthesis of Biodegradable Mg-Zn Alloy by Mechanical Alloying: Effect of Milling Time

Magnesium (Mg) is one such promising light weight metal, which is currently utilized for bio-engineering applications. Mg possesses a number of attractive characteristics that make Mg-based materials potential candidates to serve as implants for load-bearing applications in the medical industry due to its good biocompatibility and biodegradability. However, Mg and its alloys are susceptible to suffer attack in chloride containing solutions, e.g. the human body fluid or blood plasma. Thus, alloying with other metal elements is the most effective tool to improve mechanical properties and corrosion resistance of Mg. In this current work, binary Mg-Zn alloy was produced using mechanical alloying (MA) followed by compaction and sintering. The aim of this work was to study the effect of milling time on binary magnesium-zinc (Mg-Zn) alloy synthesized by mechanical alloying. A powder mixture of Mg and Zn with the composition of Mg-10wt%Zn was milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Milling process was carried out at 250rpm for various milling times i.e. 1, 2, 5, 10 and 15hours. 3% n-heptane solution was added prior to milling process to avoid excessive cold welding of the powder. Then, as-milled powder was compacted under 400MPa and sintered in a tube furnace at 350°C in argon flow. The refinement analysis of the x-ray diffraction patterns shows the presence of Mg-Zn solid solution and formation of MgZn2 when Mg-Zn powder was mechanically milled for 2hours and further. A prolonged milling time has increased the density and microhardness of the sintered Mg-Zn alloy.

Development of Biodegradable Mg-Ti Alloy Synthesized Using Mechanical Alloying

The aim of this work was to study the effect of milling time on binary magnesium-titanium (Mg-Ti) alloy synthesized by mechanical alloying. A powder mixture of Mg and Ti with the composition of Mg-15wt%Ti was milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Milling process was carried out at 400 rpm for various milling time of 2, 5, 10, 15 and 30 hours. 3% n-heptane solution was added prior to milling process to avoid excessive cold welding of the powder. Then, as-milled powder was compacted under 400 MPa and sintered in a tube furnace at 500 °C in argon flow. The refinement analysis of the x-ray diffraction patterns shows the presence of Mg-Ti solid solution when Mg-Ti powder was mechanically milled for 15 hours and further. Enhancements of Mg-Ti phase formation with a reduction in Mg crystallite size were observed with the increase in milling time. A prolonged milling time has increased the density and hardness of the sintered Mg-Ti alloy.