Corrosion Tests of Zircaloy Hull Waste to Confirm Applicability of Corrosion Model and to Evaluate Influence Factors on Corrosion Rate under Geological Disposal Conditions

2014 ◽  
Vol 1665 ◽  
pp. 195-202 ◽  
Author(s):  
Osamu Kato ◽  
Hiromi Tanabe ◽  
Tomofumi Sakuragi ◽  
Tsutomu Nishimura ◽  
Tsuyoshi Tateishi
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Pure Water ◽  
Influence Factors ◽  
Spent Fuel ◽  
Geological Disposal ◽  
Corrosion Tests ◽  
Temperature Range ◽  
Corrosion Rates ◽  
Temperature Ranges

ABSTRACTCorrosion behavior is a key issue in the assessment of disposal performance for activated waste such as spent fuel assemblies (i.e., hulls and end-pieces) because corrosion is expected to initiate radionuclide (e.g., C-14) leaching from such waste. Because the anticipated corrosion rate is extremely low, understanding and modeling Zircaloy (Zry) corrosion behavior under geological disposal conditions is important in predicting very long-term corrosion. Corrosion models applicable in the higher temperature ranges of nuclear reactors have been proposed based on considerable testing in the 523−633 K temperature range.In this study, corrosion tests were carried out to confirm the applicability of such existing models to the low temperature range of geological disposal, and to examine the influence of material, environmental, and other factors on corrosion rates under geological disposal conditions. A characterization analysis of the generated oxide film was also performed.To confirm applicability, the corrosion rate of Zry-4 in pure water with a temperature change from 303 K to 433 K was obtained using a hydrogen measuring technique, giving a corrosion rate for 180 days of 8 × 10-3 μm/y at 303 K.To investigate the influence of various factors, corrosion tests were carried out. The corrosion rates for Zry-2 and Zry-4 were almost same, and increased with a temperature increase from 303 K to 353 K. The influence of pH (12.5) compared with pure water was about 1.4 at 180 days at 303 K.

Long-Term Corrosion of Zircaloy Hull Waste under Geological Disposal Conditions: Corrosion Correlations, Factors Influencing Corrosion, Corrosion Test Data, and Preliminary Evaluation

2014 ◽  
Vol 1665 ◽  
pp. 203-214 ◽  
Author(s):  
Hiromi Tanabe ◽  
Tomofumi Sakuragi ◽  
Hideaki Miyakawa ◽  
Ryota Takahashi
Keyword(s):  
Low Temperature ◽  
Corrosion Rate ◽  
Preliminary Evaluation ◽  
Leaching Tests ◽  
Geological Disposal ◽  
Temperature Range ◽  
Corrosion Rates ◽  
Factors Influencing ◽  
Hull Waste

ABSTRACTThe carbon-14 generated in Zircaloy (Zry) hull waste is considered an important radionuclide in the TRU waste geological disposal concept in Japan. Given that the metal Zry is highly corrosion-resistant in the anaerobic and low-temperature conditions of the repository, and that the C-14 release rate is assumed to be controlled by the corrosion rate, a variety of corrosion and leaching tests have been performed. However, since the Zry corrosion rate is extremely slow, it is not possible to predict long-term corrosion behavior through low-temperature corrosion tests conducted in a reasonable time period. A vast amount of testing has been conducted in the higher-temperature range of 523 to 633 K, and corrosion correlations have been obtained from these tests. Corrosion correlations have been used to predict the corrosion rate of Zry in a tuff repository. Long-term Zry autoclave corrosion data have been analyzed to develop new corrosion correlations. Extrapolating these correlations to a lower temperature range requires verification that the mechanisms do not change over the range of testing and extrapolation. Factors that influence corrosion rates under geological disposal conditions, such as material and environmental factors, should also be examined. Corrosion correlations, factors influencing corrosion rates, the results of corrosion and leaching tests, and a preliminary evaluation are discussed.

High-Temperature Corrosion of Ni3Al+ 2.9%Cr Alloy in Ar-0.2%SO2 Gas

2018 ◽  
Vol 775 ◽  
pp. 441-447
Author(s):  
Dong Bok Lee ◽  
Min Jung Kim ◽  
Gyu Chul Cho ◽  
Soon Young Park ◽  
Poonam Yadav
Keyword(s):  
High Temperature ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Kirkendall Effect ◽  
High Temperature Corrosion ◽  
Scale Spallation ◽  
Corrosion Tests ◽  
Cooling Period ◽  
Corrosion Kinetics ◽  
Period 2

The high-temperature corrosion behavior of Ni3Al+2.9 wt% Cr alloy was studied in SO2-containing environment. Corrosion tests were carried out at 900, 1000, and 1100 °C for 100 h in atmospheric Ar-0.2% SO2 gas. The alloy corroded relatively slowly due mainly to formation of Al2O3 in the scale. Its corrosion kinetics deviated from the parabolic corrosion rate law to a certain extent owing to ensuing scale spallation. This was attributed to (1) stress generated during scaling and the subsequent cooling period, (2) voids that formed due to the Kirkendall effect, and (3) incorporation of sulfur in the scale. The scale that formed after corrosion at 900 °C consisted of the outer NiO scale, middle NiAl2O4 scale, and inner Al2O3 scale. The increased corrosion rate at 1000 and 1100 °C led to formation of the outer NiO scale, and inner Al2O3 scale.

scholarly journals The Corrosion Behavior of Sputter-Deposited Nanocrystalline W-Cr Alloys in Nacl and NaohaSolutions

1970 ◽  
Vol 25 ◽  
pp. 53-61
Author(s):  
Minu Basnet ◽  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Chromium Content ◽  
Open Circuit ◽  
Nacl Solution ◽  
Corrosion Rates ◽  
Naoh Solution ◽  
Order Of Magnitude ◽  
Sputter Deposited

The corrosion behavior of the sputter-deposited nanocrystalline W-Cr alloys wasstudied in 0.5 M NaCl and alkaline 1 M NaOH solutions at 25°C, open to air usingimmersion tests and electrochemical measurements. Chromium metal acts synergisticallywith tungsten in enhancing the corrosion resistance of the sputter-deposited W-Cr alloys soas to show higher corrosion resistance than those of alloy-constituting elements in both 0.5M NaCl and 1 M NaOH solutions. In particular, the nanocrystalline W-Cr alloys containing25-91 at% chromium showed about one order of magnitude lower corrosion rates (that is,about 1-2 × 10-3 mm.y-1) than those of tungsten and chromium metals even for prolongedimmersion in 0.5 M NaCl solution at 25°C. On the other hand, the corrosion rate of thesputter-deposited W-Cr alloys containing 25-75 at % chromium was decreased significantlywith increasing chromium content and showed lowest corrosion rates (that is, 1.5-2.0 × 10-3 mm.y-1) after immersed for prolonged immersion in 1 M NaOH solution. The corrosion ratesof these nanocrystalline W-(25-75)Cr alloys are nearly two orders of magnitude lower thanthat of tungsten and more than one order of magnitude lower corrosion rate than that ofsputter-deposited chromium metal in 1 M NaOH solution. The corrosion-resistant of all theexamined sputter-deposited W-Cr alloys in 0.5 M NaCl solution is higher than in alkaline 1M NaOH solution at 25°C. Open circuit potentials of all the examined W-Cr alloys areshifted to more noble direction with increasing the chromium content in the alloys afterimmersion for 72 h in both 0.5 M NaCl and 1 M NaOH solutions at 25°C, open to air.Keywords: Sputter deposition, nanocrystalline W-Cr alloys, corrosion test, electrochemicalmeasurement, NaCl and NaOH solutions.DOI:  10.3126/jncs.v25i0.3300Journal of Nepal Chemical Society Volume 25, 2010 pp 53-61

A Comparison and Abstraction of the Commercial Spent Fuel Corrosion Experiments in the U.S.

2002 ◽  
Vol 757 ◽  
Author(s):  
Eric R. Siegmann
Keyword(s):  
Corrosion Rate ◽  
Spent Fuel ◽  
Release Rates ◽  
Water Contact ◽  
Contact Mode ◽  
Corrosion Rates ◽  
Single Temperature ◽  
Flow Through ◽  
Distribution Sensitivity ◽  
Temperature Dependent Model

ABSTRACTThis paper compares the results of three different fuel corrosion experiments by taking the existing corrosion data reported for various temperatures and recalculating corrosion rates at a single temperature of 25°C using a temperature dependent model developed elsewhere. Three types of light water reactor fuel corrosion tests (sometimes called dissolution or alteration tests) were performed in support of Yucca Mountain Project. The tests used three water contact modes and various fuel burnups. All measurements were adjusted for temperature differences and then compared. Five different isotopes (cesium, technetium, iodine, strontium, and, in the flow-through tests, uranium) were considered as a measure of corrosion. The data used represent over ten years of experiments with about nine different fuel types. Most experiments were with repository type fluids, containing dissolved constituents such as carbonate, calcium and silicon. The results show that all of the experiments predict similar fuel corrosion rates. Small differences in the isotope release rates are observed and incorporated in the abstracted uncertainty. Water contact mode (flow-through, batch, or drip) does not seem to be very important although the drip tests introduced larger variations. In developing a corrosion abstraction, all of the isotope measurements were considered equally. The distribution of release rates was used directly to develop the uncertainty. The mean corrosion rate was 1.8 × 10-4 fraction/year at 25°C (5%-95% range = 5.7 × 10-5 to 1.7 × 10-3). Using the derived corrosion rate for 25°C, and considering rapid axial splitting of the cladding, the CSNF fuel rod is expected to corrode in less than 2,000 years. The abstraction uses all the available experiments performed with water containing carbonates, silicon, or calcium and irradiated fuel to produce a corrosion rate distribution. Sensitivity studies using this corrosion rate abstraction in the TSPA-SR analysis show very small changes in dose (3%) in response to changes in the UO2 corrosion abstraction.

The Corrosion Behavior of Niobium in Hydrochloric Acid Solutions

CORROSION ◽  
1980 ◽  
Vol 36 (10) ◽  
pp. 554-558 ◽  
Author(s):  
B. S. COVINO ◽  
J. P. CARTER ◽  
S. D. CRAMER
Keyword(s):  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Mineral Resources ◽  
The United States ◽  
General Corrosion ◽  
Ferric Ion ◽  
Acid Solutions ◽  
Corrosion Rates ◽  
Hydrochloric Acid Solutions

Abstract Studies to better understand the corrosion behavior of niobium in hydrochloric acid solutions have been conducted as part of the Bureau of Mines’ effort to conserve the United States’ mineral resources. A study of the general corrosion behavior of niobium as a function of acid concentration, time, oxygen, and added ferric ion is reported. Weight loss (corrosion) tests were performed in air saturated (agitated and static) and helium saturated (agitated) hydrochloric acid solutions ranging from 1N to 10N at temperatures from 35 to 100 C and exposures up to 60 days. The 30 day corrosion rates ranged from 0.0 μm/y in 35 C air saturated (agitated) 1N HCl to 230 μm/y in air saturated (static) 9.8N HCl at 85 C. Although the corrosion rates decreased rapidly for times up to 30 days, the rates for 30 and 60 days were essentially identical. The presence of air did not affect the corrosion rate of niobium, while the presence of only 70 ppm of ferric ion reduced the corrosion rate in most air saturated 5N and 10N HCl solutions.

Corrosion of Refinery Equipment During Acid Cleaning★

CORROSION ◽  
1958 ◽  
Vol 14 (12) ◽  
pp. 43-49 ◽  
Author(s):  
K. R. WALSTON ◽  
A. DRAVNIEKS
Keyword(s):  
Hydrogen Sulfide ◽  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Iron Oxides ◽  
Chemical Cleaning ◽  
Refinery Equipment ◽  
Acid Cleaning ◽  
Corrosion Rates ◽  
Temperature Ranges ◽  
Practical Temperature

Abstract Economical, effective and relatively easy to handle, hydrochloric acid is being widely used as a solvent for chemical cleaning of refinery equipment. Inhibitors must be added to retard corrosion during cleaning operations, but these inhibitors must not prevent dissolution of the scale to be removed. Practical temperature ranges for cleaning are given. The corrosion rate increases exponentially with temperature and with acid concentration. The corrosion .rates of various metals in 5 percent inhibited hydrochloric acid are given. The influence of inhibitors on the rates of dissolution of iron oxides and sulfides are shown. Four typical cases of corrosion occurring during acid cleaning are discussed with special safety precautions that should be observed during cleaning operations. The influence of commonly present substances such as hydrogen sulfide is shown to increase the rate of corrosion. 5.9.2

Effect of CO2 Partial Pressure on CO2/H2S Corrosion of Oil Tube Steels

2014 ◽  
Vol 962-965 ◽  
pp. 407-410
Author(s):  
Ying Wang
Keyword(s):  
Corrosion Rate ◽  
Partial Pressure ◽  
Corrosion Morphology ◽  
Corrosion Tests ◽  
Corrosion Rates ◽  
Tube Steels ◽  
Corrosion Behaviors ◽  
Rate Calculation

The CO2/H2S corrosion behaviors of oil tube steels N80 and P110 at different CO2 partial pressure (45psi, 135psi, 225psi, 315psi) were investigated by corrosion tests, corrosion rate calculation and corrosion morphology observation. The results show that at different CO2 partial pressure, super-serious CO2/H2S corrosion occurs on steel N80 and steel P110. With the increase of CO2 partial pressure, the CO2/H2S corrosion rates of both steels increase gradually.

The corrosion behavior of marine aluminum alloy MIG welded joints in a simulated tropical marine atmosphere

2021 ◽  
Vol 63 (2) ◽  
pp. 151-156
Author(s):  
Lihua Gong ◽  
Weimin Guo ◽  
Feng Pan
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Rate ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Welded Joint ◽  
Salt Spray ◽  
Atmospheric Environment ◽  
Cycle Period ◽  
Corrosion Tests ◽  
Immersion Corrosion

Abstract The influence of metal inert-gas arc welding (MIG) on the corrosion behavior of 6061-T6 aluminum alloy in a simulated tropical marine atmospheric environment (related to high temperature, high humidity and high salt spray) were examined by dry-wet alternate immersion corrosion tests. The equivalent conversion was used to design the accelerated test time. The results show that in the initial stage, the intermetallic compound, rich in Fe, Si and Cu, had little influence on corrosion resistance in the heat-affected zone. For a corrosion time of 3 days in a tropical marine atmospheric environment, the corrosion rate of the welded joint increased rapidly, even reaching 3.5 times that of the base metal. Though the corrosion products had significant impact on slowing down the corrosion rate, as with the base metal, the corrosion rate of the welded joint was nearly double that of the base metal during the longest cycle period involving alternate immersion corrosion tests for 20 days.

Effect of Sn on Corrosion Resistance of Mg-6Al-1.2Y-0.9Nd Alloy

2011 ◽  
Vol 117-119 ◽  
pp. 1334-1337 ◽  
Author(s):  
Hai Juan Kang ◽  
Quan An Li ◽  
Wei Zhou ◽  
Qing Zhang
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Scale Analysis ◽  
Nacl Solution ◽  
Corrosion Tests ◽  
Corrosion Scale ◽  
Static Corrosion

The effect of Sn addition on corrosion behavior of Mg-6Al-1.2Y-0.9Nd alloy in 3.5wt.% NaCl solution has been researched by static corrosion tests, corrosion morphologies observation, microstructure and corrosion scale analysis. The result shows that, with the content of Sn increasing, the corrosion rate decreases at first and then increases. When the addition of Sn is 1wt.%, the corrosion rate is the lowest and the corrosion resistance is improved obviously.

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