Detecting and imaging stress corrosion cracking in stainless steel, with application to inspecting storage canisters for spent nuclear fuel
Abstract not provided
Remillieux, Marcel C.↗
Engineering topics
Anderson, Brian E.
Publications and source records attributed to Anderson, Brian E..
A comparison of impulse response modification techniques for time reversal with application to crack detection
Not Available
Young, Sarah M.↗
Nonlinearity from stress corrosion cracking as a function of chloride exposure time using the time reversed elastic nonlinearity diagnostic
The Time Reversed Elastic Nonlinearity Diagnostic (TREND) has a long history of successful nondestructive detection of cracks in solids using nonlinear indicators. Recent research implemented TREND to find stress corrosion cracking (SCC) in the heat-affected zone adjacent to welds in stainless steel. SCC development around welds is likely to occur due to the temperature and chemical exposure of steel canisters housing spent nuclear fuel. The ideal SCC detection technique would quantify the size and extent of the SCC, rather than just locating it, as TREND has been used for in the past. The current paper explores TREND's ability to detect an assumed increase in SCC over time using 13 samples exposed to a magnesium chloride (MgCl 2 ) bath for different lengths of time. The samples are then scanned with TREND and nonlinearity is quantified for each scan point and each sample. The results suggest that TREND can be used to not only locate SCC in the heat-affected zone, but also track an increase in nonlinearity, and thereby an increase in damage, in samples exposed to the MgCl 2 solution for a longer duration.
42 ENGINEERING↗
Nonlinear resonant ultrasound spectroscopy of stress corrosion cracking in stainless steel rods
Stainless steel containers are susceptible to stress corrosion cracking (SCC) under certain stress and corrosion conditions. Nonlinear ultrasonic techniques are very sensitive to the early presence of damage, more so than linear techniques. Nonlinear Resonant Ultrasound Spectroscopy (NRUS) is used here to measure a nonlinear shift in the resonance frequency due to a cumulative amount of SCC. Steel rods are immersed in a heated magnesium chloride solution and removed after different exposure times. NRUS measurements are conducted using the fundamental longitudinal mode of vibration. Rods exposed longer generally have a larger resonance frequency shift and are therefore more nonlinear. Thus NRUS might offer a means of detecting a cumulative SCC damage in a sample.
36 MATERIALS SCIENCE↗
Estimating the Penetration Depth and Orientation of Stress Corrosion Cracks Using Time-Reversal Acoustics
Austenitic stainless steels are known to be susceptible to stress corrosion cracking (SCC), which is an aggressive type of corrosion that exists when a material under tensile stress is placed in a corrosive environment. This is of particular concern as the processing (i.e., cold rolling) and construction (welding) of storage canisters produce an inherent residual stress in metals that can lead to SCC. In this context, our objective is to study the formation of stress corrosion cracks within Type 304L stainless steel, which is frequently used in containers for used nuclear fuel disposal. The conditions present in storage canisters (i.e., elevated temperatures, high residual stresses near welds, and exposure to humidity and chloride) make them susceptible to SCC, potentially leading to critical through-wall failure, and thus loss of containment. The timescales on which through-wall failure is expected in a storage canister under typical conditions is on the order of tens of years. While through-wall flaws are catastrophic (e.g., release of helium and fission gases), the long timescales allow for routine inspection, and potentially mitigation, providing methods exist. This paper is focused on the former problem, i.e. detection of SCC, and the development of a tool for inspection of storage canisters. We will discuss the recent work we did on detecting the presence of SCC as well as imaging on its orientation and penetration depth using an acoustic technique developed at Los Alamos National Laboratory (LANL). This technique has been applied successfully in the laboratory on stainless steel samples with SCC provided by General Electric (GE) and the Electric Power Research Institute (EPRI). Recently, we have also demonstrated that this technique can be deployed for field inspections in tight and confined spaces. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Three-dimensional time reversal communications in elastic media
Our letter presents a series of vibrational communication experiments, using time reversal, conducted on a set of cast iron pipes. Time reversal has been used to provide robust, private, and clean communications in many underwater acoustic applications. Also, the use of time reversal to communicate along sections of pipes and through a wall is demonstrated here in order to overcome the complications of dispersion and multiple scattering. These demonstrations utilize a single source transducer and a single sensor, a triaxial accelerometer, enabling multiple channels of simultaneous communication streams to a single location.
42 ENGINEERING↗
Ultrasonic radiation from wedges of cubic profile: Experimental results
This work presents experimental results demonstrating the increase in ultrasonic radiation obtained from a wedge of cubic profile relative to a plate of uniform thickness. The wedge of cubic profile provides high efficiency sound radiation matching layer from a mounted piezoelectric transducer into the surrounding air. Previous research on structures with indentations of power-law profile has focused on vibration mitigation using the so called “acoustic black-hole” effect, whereas here such structures are used to enhance ultrasonic radiation. The work provides experimental verification of the numerical results of Remillieux et al. (2014).
30 DIRECT ENERGY CONVERSION↗
Depth profile of a time-reversal focus in an elastic solid
The out-of-plane velocity component is focused on the flat surface of an isotropic solid sample using the principle of time reversal. This experiment is often reproduced in the context of nondestructive testing for imaging features near the surface of the sample. However, it is not clear how deep the focus extends into the bulk of the sample and what its profile is. In this paper, this question is answered using both numerical simulations and experimental data. The profiles of the foci are expressed in terms of the wavelengths of the dominant waves, based on the interpretation of the Lamb’s problem and the use of the diffraction limit.
36 MATERIALS SCIENCE↗
Improving spatio-temporal focusing and source reconstruction through deconvolution
Not Available
Anderson, Brian E.↗
Three component vibrational time reversal communication
Time reversal provides an optimal prefilter matched signal to apply to a communication signal before signal transmission. Time reversal allows compensation for wave speed dispersion and can function well in reverberant environments. Time reversal can be used to focus elastic energy to each of the three components of motion independently. A pipe encased in concrete was used to demonstrate the ability to conduct communications of information using three component time reversal. Furthermore, the ability of time reversal to compensate for multi-path distortion (overcoming reverberation) will be demonstrated and the rate of signal communication will be presented. [The U.S. Department of Energy, through the LANL/LDRD Program, is gratefully acknowledged for supporting this work.]
42 ENGINEERING↗
Modern Application of Time-Reversal to Seismic Source characterization
This report describes the pleasant tenets of time-reversal.
58 GEOSCIENCES↗
Experimental Investigations – End of Year Technical Report
This report summarizes technical work conducted by LANL staff and international collaborators in support of the UFD Storage Experimentation effort. The current focus of this technical work is two-fold: 1) on the detection and imaging of a failure mechanism known as stress corrosion cracking (SCC) in stainless steel (304L) using the nonlinear ultrasonic technique known as TREND, and 2) on the evaluation of concrete integrity in structures with degradation and re-bar corrosion due to carbonation (i.e., CO 2 exposure), also using nonlinear ultrasonic techniques. The latter was performed in conjunction with the Aix-Marseille University and CNRS Mechanics and Acoustics laboratory as part of the French National Research Agency (ANR) EvaDéOs project. The conclusion to be made from these results is that nonlinear ultrasound, in particular TREND, is applicable as a spot inspection technique in both stainless steel and concrete, with the potential to be applied to be more broadly applied to other materials and environments. The nonlinear signature measured is related to the degree of damage/degradation. The localized nature of the measurement allows for identification of mechanical defects and localization of degraded regions. Further work is necessary to characterize the degradation (e.g., sensitivity, size of flaws, type of damage, residual strength, etc.)
25 ENERGY STORAGE↗
Impact Reduction in Football Helmets due to Application of Helmets due to Application of Externally Applied Foam [Slides]
Concussions, due to sports hard impacts, are a real concern for athletes, family members fans of the sport and the public health family members, fans of the sport and the public health. It is estimated that the number of sport-related concussions in the United States is around 1.6 and 3.8 million per year. The measurements utilize a football helmet placed on a mannequin head and consider the response of accelerometers and a high-precision microphone mounted to the mannequin head due to various types of impact tests.
36 MATERIALS SCIENCE↗
Identifying Cracks in Stainless Steel Using Time Reversal Techniques [Slides]
Nuclear power plants produce more used nuclear fuel (UNF) in their lifetime than they have capacity to store. Dry storage for UNF was made as a storage option in addition to on-site cooling pools. These casks of concrete and steel, intended to have a lifetime of a few decades, may need to be used for centuries. A method is needed to nondestructively test these casks for stress corrosion cracking (SCC).
36 MATERIALS SCIENCE↗
Experimental Investigations -- Midyear Status Report
This report summarizes technical work conducted by LANL staff and international collaborators in support of the UFD Storage Experimentation effort. The current focus of this technical work is two-fold: 1) on the stainless steel (304L) failure mechanism known as stress corrosion cracking (SCC), and 2) on the concrete integrity under degradation conditions (e.g., thermal, radiation, alkali-aggregate reactions). As these issues are common among our international partners, a significant effort has been put forth to engage foreign programs in a mutually beneficial collaborative program on these topics. Results from these collaborations, notably with Japan, France and Switzerland, are highlighted.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗