Radionuclide tracing based in situ corrosion and mass transport monitoring of 316L stainless steel in a molten salt closed loop.

In the study, we report an in situ corrosion and mass transport monitoring method developed using a radionuclide tracing technique for the corrosion study of 316L stainless steel (316L SS) in a NaCl-MgCl eutectic molten salt natural circulation loop. This method involves cyclotron irradiation of a small tube section with 16 MeV protons, later welds at the hot leg of the molten salt flow loop, generating radionuclides Cr, Mn, and Co at the salt-alloy interface. By measuring the activity variations of these radionuclides at different sections along the loop, both the in situ monitoring of the corrosion attack depth of 316L SS and corrosion product transport and its precipitation in flowing NaCl-MgCl molten salt are achieved.

Radionuclide Tracing Based in situ Corrosion and Mass Transport Monitoring of 316L Stainless Steel in a Molten Salt Closed Loop.

In the study, we report an corrosion and mass transport monitoring method developed using a radionuclide tracing technique for the corrosion study of 316L stainless steel (316L SS) in a NaCl-MgCl eutectic molten salt natural circulation loop. This novel method involved cyclotron irradiation of a small tube section with 16 MeV protons, later welded at the hot leg of the molten salt flow loop, generating radionuclides , , and at the salt-alloy interface. By measuring the activity variations of these radionuclides at different sections along the loop, both the monitoring of the corrosion attack depth of 316L SS and corrosion product transport and its precipitation in flowing NaCl-MgCl molten salt were achieved.

Integrated High-Throughput and Machine Learning Methods to Accelerate Discovery of Molten Salt Corrosion-Resistant Alloys.

Insufficient availability of molten salt corrosion-resistant alloys severely limits the fruition of a variety of promising molten salt technologies that could otherwise have significant societal impacts. To accelerate alloy development for molten salt applications and develop fundamental understanding of corrosion in these environments, here an integrated approach is presented using a set of high-throughput (HTP) alloy synthesis, corrosion testing, and modeling coupled with automated characterization and machine learning. By using this approach, a broad range of CrFeMnNi alloys are evaluated for their corrosion resistances in molten salt simultaneously demonstrating that corrosion-resistant alloy development can be accelerated by 2 to 3 orders of magnitude.

In Situ Corrosion Monitoring of the T91 Alloy in a Molten Chloride Salt Using a Miniaturized Electrochemical Probe for High-Throughput Applications.

Corrosion sensing is essential to monitor and safeguard materials' health in molten salts. The present study developed a three-electrode-array minisensor for high-temperature molten salt corrosion monitoring. By using the developed sensor, the impurity-driven corrosion of T91 by a fission product, europium, in the LiCl-KCl eutectic molten salt has been studied.

Temperature-Dependent Properties of Molten LiBeF Salt Using Molecular Dynamics.

Molten lithium tetrafluoroberyllate (LiBeF) salt, also known as FLiBe, with a 2:1 mixture of LiF and BeF is being proposed as a coolant and solvent in advanced nuclear reactor designs, such as the molten salt reactor or the fluoride salt cooled high-temperature reactor. We present the results on the structure and properties of FLiBe over a wide range of temperatures, 0-2000 K, from high-throughput molecular dynamics simulation using a supercell model of 504 atoms. The variations in the local structures of solid and liquid FLiBe with temperature are discussed in terms of a pair distribution function, coordination number, and bond angle distribution.

Corrosion and Thermal Stability of CrMnFeNi High Entropy Alloy in Molten FLiBe Salt.

The corrosion behavior of the FCC CrMnFeNi high entropy alloy (HEA) after exposure to molten FLiBe salt at 700 °C for 1000 hours, has been investigated. Results show that the HEA lost a higher mass compared to the reference 316 H stainless steel due to the dissolution of Mn into the molten salt. The loss of Mn from the alloy appeared to discourage the dissolution of Cr in the molten fluoride salts which is widely recognized as the mechanism of corrosion degradation.

Best practices for preparing radioactive specimens for EBSD analysis.

A wide variety of specimen preparation techniques are available for ensuring that specimen surface finish has the acceptable quality for electron backscatter diffraction (EBSD) analysis. These techniques include but are not limited to vibratory polishing, broad, and focused ion beam milling. They have been widely implemented in the field of nuclear materials science with a varying degree of success.

Tribochemical Wear of Diamond-Like Carbon-Coated Atomic Force Microscope Tips.

Nanoscale wear is a critical issue that limits the performance of tip-based nanomanufacturing and nanometrology processes based on atomic force microscopy (AFM). Yet, a full scientific understanding of nanoscale wear processes remains in its infancy. It is therefore important to quantitatively understand the wear behavior of AFM tips.

Ultralow nanoscale wear through atom-by-atom attrition in silicon-containing diamond-like carbon.

Understanding friction and wear at the nanoscale is important for many applications that involve nanoscale components sliding on a surface, such as nanolithography, nanometrology and nanomanufacturing. Defects, cracks and other phenomena that influence material strength and wear at macroscopic scales are less important at the nanoscale, which is why nanowires can, for example, show higher strengths than bulk samples. The contact area between the materials must also be described differently at the nanoscale.